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Sample records for wedge high tibial

  1. Open wedge high tibial osteotomy using three-dimensional printed models: Experimental analysis using porcine bone.

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    Kwun, Jun-Dae; Kim, Hee-June; Park, Jaeyoung; Park, Il-Hyung; Kyung, Hee-Soo

    2017-01-01

    The purpose of this study was to evaluate the usefulness of three-dimensional (3D) printed models for open wedge high tibial osteotomy (HTO) in porcine bone. Computed tomography (CT) images were obtained from 10 porcine knees and 3D imaging was planned using the 3D-Slicer program. The osteotomy line was drawn from the three centimeters below the medial tibial plateau to the proximal end of the fibular head. Then the osteotomy gap was opened until the mechanical axis line was 62.5% from the medial border along the width of the tibial plateau, maintaining the posterior tibial slope angle. The wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The open wedge HTO surgery was reproduced in porcine bone using the 3D-printed model and the osteotomy site was fixed with a plate. Accuracy of osteotomy and posterior tibial slope was evaluated after the osteotomy. The mean mechanical axis line on the tibial plateau was 61.8±1.5% from the medial tibia. There was no statistically significant difference (P=0.160). The planned and post-osteotomy correction wedge angles were 11.5±3.2° and 11.4±3.3°, and the posterior tibial slope angle was 11.2±2.2° pre-osteotomy and 11.4±2.5° post-osteotomy. There were no significant differences (P=0.854 and P=0.429, respectively). This study showed that good results could be obtained in high tibial osteotomy by using 3D printed models of porcine legs. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Stress analysis of the tibial plateau according to the difference of blade path entry in opening wedge high tibial osteotomy

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    Lee, Jun Woo; Xin, YuanZhu; Yang, Seok Jo [Chungnam National University, Daejeon (Korea, Republic of); Ji, Jong Hun; Panchal, Karnav; Kwon, Oh Soo [The Catholic University of Korea, Daejeon (Korea, Republic of)

    2015-03-15

    High tibial osteotomy (HTO) has been used to successfully treat patients with genu varus deformities that can improve mechanical function and condition in the knee joint. Clinical studies have reported that bow legs often occur with a concentrated load on the varus of the tibia. This study aimed to analyze and verify the clinical test data result by utilizing the three-dimensional (3D) static finite element method (FEM). The 3D model of lower extremities, which include the femur, tibia, meniscus, and knee articular cartilage, was created using the images from a computer tomography scan and magnetic resonance imaging. In this report, we compared changes in stress distribution and force reaction on the tibial plateau because of critical problems caused by unexpected changes in the tibial posterior-slope angle because of HTO. The results showed that the 5 .deg. wedge-angle virtual opening wedge HTO without and with the posterior-slope angle shows has a load concentration of approximately 60% and 45% in the medial region, respectively.

  3. Changes in patellofemoral alignment do not cause clinical impact after open-wedge high tibial osteotomy.

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    Lee, Yong Seuk; Lee, Sang Bok; Oh, Won Seok; Kwon, Yong Eok; Lee, Beom Koo

    2016-01-01

    The objectives of this study were (1) to evaluate the clinical and radiologic outcomes of open-wedge high tibial osteotomy focusing on patellofemoral alignment and (2) to search for correlation between variables and patellofemoral malalignment. A total of 46 knees (46 patients) from 32 females and 14 males who underwent open-wedge high tibial osteotomy were included in this retrospective case series. Outcomes were evaluated using clinical scales and radiologic parameters at the last follow-up. Pre-operative and final follow-up values were compared for the outcome analysis. For the focused analysis of the patellofemoral joint, correlation analyses between patellofemoral variables and pre- and post-operative weight-bearing line (WBL), clinical score, posterior slope, Blackburn Peel ratio, lateral patellar tilt, lateral patellar shift, and congruence angle were performed. The minimum follow-up period was 2 years and median follow-up period was 44 months (range 24-88 months). The percentage of weight-bearing line was shifted from 17.2 ± 11.1 to 56.7 ± 12.7%, and it was statistically significant (p patellofemoral malalignment, the pre-operative weight-bearing line showed an association with the change in lateral patellar tilt and lateral patellar shift (correlation coefficient: 0.3). After open-wedge high tibial osteotomy, clinical results showed improvement, compared to pre-operative values. The patellar tilt and lateral patellar shift were not changed; however, descent of the patella was observed. Therefore, mild patellofemoral problems should not be a contraindication of the open-wedge high tibial osteotomy. Case series, Level IV.

  4. The results of high tibial open wedge osteotomy in patients with varus deformity

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    Mahmood Jabalameli

    2013-07-01

    Full Text Available Background: High tibial open wedg osteotomy is one of the most important modality for treatment of varus deformity in order to correct deformity and improving signs and symptoms of patients with primary degenerative osteoarthritis. The aim of this study was to investigate the results of high tibial open wedge osteotomy in patients with varus deformities.Methods: This retrospective study conducted on twenty nine patients (36 knees undergone proximal tibial osteotomy operation in Shafa Yahyaian University Hospital from 2004 to 2010. Inclusion criteria were: age less than 60 years, high physical activity, varus deformity and involvement of medical compartment of knee. Patients with obesity, smoking, patelofemoral pain, lateral compartment lesion, deformity degree more than 20 degree, extension limitation and range of motion less than 90 degree were excluded. The clinical and radiologic characteristics were measured before and after operation.Results: Fourteen patients were females. All of them were younger than 50 years, with mean (±SD 27.64 (±10.88. The mean (±SD of follow up time was 4.33 (±1.7. All the patients were satisfied with the results of operation. Tenderness and pain decreased in all of them. In all patients autologus bone graft were used, in 15 cases (42.5% casting and in the rest T.Buttress plate were used for fixation of fractures. In both groups of primary and double varus the International knee documentation committee (IKDC and modified Larson indices were improved after operation, but there was no significant difference between two groups.Conclusion: High tibial open wedge osteotomy can have satisfying results in clinical signs and symptoms of patients with primary medial joint degenerative osteoarthritis. This procedure also may correct the deformity and improves the radiologic parameters of the patients.

  5. Early weight bearing versus delayed weight bearing in medial opening wedge high tibial osteotomy: a randomized controlled trial.

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    Lansdaal, Joris Radboud; Mouton, Tanguy; Wascher, Daniel Charles; Demey, Guillaume; Lustig, Sebastien; Neyret, Philippe; Servien, Elvire

    2017-12-01

    The need for a period of non-weight bearing after medial opening wedge high tibial osteotomy remains controversial. It is hypothesized that immediate weight bearing after medial opening wedge high tibial osteotomy would have no difference in functional scores at one year compared to delayed weight bearing. Fifty patients, median age 54 years (range 40-65), with medial compartment osteoarthritis, underwent a medial opening wedge high tibial osteotomy utilizing a locking plate without bone grafting. Patients were randomized into an Immediate or a Delayed (2 months) weight bearing group. All patients were assessed at one-year follow-up and the two groups compared. The primary outcome measure was the IKS score. Secondary outcome measures included the IKDC score, the VAS pain score and rate of complications. The functional scores significantly improved in both groups. The IKS score increased from 142 ± 31 to 171 ± 26 in the Immediate group (p bearing after medial opening wedge high tibial osteotomy had no effect on functional scores at 1 year follow-up and did not significantly increase the complication rate. Immediate weight bearing after medial opening wedge high tibial osteotomy appears to be safe and can allow some patients a quicker return to activities of daily living and a decreased convalescence period. II.

  6. High tibial closing wedge osteotomy for medial compartment osteoarthrosis of knee

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    Tuli S

    2008-01-01

    Full Text Available Background: Most patients of symptomatic osteoarthrosis of knee are associated with varus malalignment that is causative or contributory to painful arthrosis. It is rational to correct the malalignment to transfer the functional load to the unaffected or less affected compartment of the knee to relieve symptoms. We report the outcome of a simple technique of high tibial osteotomy in the medial compartment of osteoarthrosis of the knee. Materials and Methods: Between 1996 and 2004 we performed closing wedge osteotomy in 78 knees in 65 patients. The patients selected for osteotomy were symptomatic essentially due to medial compartment osteoarthrosis associated with moderate genu varum. Of the 19 patients who had bilateral symptomatic disease 11 opted for high tibial osteotomy of their second knee 1-3 years after the first operation. Preoperative grading of osteoarthrosis and postoperative function was assessed using Japanese Orthopaedic Association (JOA rating scale. Results: At a minimum follow-up of 2 years (range 2-9 years 6-10° of valgus correction at the site of osteotomy was maintained, there was significant relief of pain while walking, negotiating stairs, squatting and sitting cross-legged. Walking distance in all patients improved by two to four times their preoperative distance of 200-400 m. No patient lost any preoperative knee function. The mean JOA scoring improved from preoperative 54 (40-65 to 77 (55-85 at final follow-up. Conclusion: Closing wedge high tibial osteotomy performed by our technique can be undertaken in any setup with moderate facilities. Operation related complications are minimal and avoidable. Kirschner wire fixation is least likely to interfere with replacement surgery if it becomes necessary.

  7. Open-Wedge High Tibial Osteotomy: RCT 2 Years RSA Follow-Up.

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    Lind-Hansen, Thomas Bruno; Lind, Martin Carøe; Nielsen, Poul Torben; Laursen, Mogens Berg

    2016-11-01

    We investigated the influence of three different bone grafting materials on stability and clinical outcome of the healing open-wedge high tibial osteotomy (OW-HTO) with immediate partial weight bearing. A total of 45 (3 × 15) patients were randomized to injectable calcium phosphate cement (Calcibon; Biomet-Merck Biomaterials GmbH, Darmstadt, Germany), local bone autograft, or iliac crest autograft. Stability of the bony healing was evaluated with radiostereometric analysis (RSA) up to 24 months postoperatively. Clinical outcome was evaluated with the knee injury and osteoarthritis outcome score (KOOS). RSA revealed translations and rotations close to zero regardless of bone grafting material, with no statistically significant differences between the groups. Clinically, the Calcibon group had lower quality of life KOOS subscore at 2 years follow-up. We conclude that with a stable implant and 6 weeks of partial weight bearing, local autografting is sufficient to achieve solid bone consolidation following OW-HTO. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Clinical Experience Using a 3D-Printed Patient-Specific Instrument for Medial Opening Wedge High Tibial Osteotomy

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    Jesse Chieh-Szu Yang

    2018-01-01

    Full Text Available Purpose. High tibial osteotomy (HTO has been adopted as an effective surgery for medial degeneration of the osteoarthritis (OA knee. However, satisfactory outcomes necessitate the precise creation and distraction of osteotomized wedges and the use of intraoperative X-ray images to continually monitor the wedge-related manipulation. Thus HTO is highly technique-demanding and has a high radiation exposure. We report a patient-specific instrument (PSI guide for the precise creation and distraction of HTO wedge. Methods. This study first parameterized five HTO procedures to serve as a design rationale for an innovative PSI guide. Preoperative X-ray and computed tomography- (CT- scanning images were used to design and fabricate PSI guides for clinical use. The weight-bearing line (WBL of the ten patients was shifted to the Fujisawa’s point and instrumented using the TomoFix system. The radiological results of the PSI-guided HTO surgery were evaluated by the WBL percentage and tibial slope. Results. All patients consistently showed an increased range of motion and a decrease in pain and discomfort at about three-month follow-up. This study demonstrates the satisfactory accuracy of the WBL adjustment and tibial slope maintenance after HTO with PSI guide. For all patients, the average pre- and postoperative WBL are, respectively, 14.2% and 60.2%, while the tibial slopes are 9.9 and 10.1 degrees. The standard deviations are 2.78 and 0.36, respectively, in postoperative WBL and tibial slope. The relative errors of the pre- and postoperative WBL percentage and tibial slope averaged 4.9% and 4.1%, respectively. Conclusion. Instead of using navigator systems, this study integrated 2D and 3D preoperative planning to create a PSI guide that could most likely render the outcomes close to the planning. The PSI guide is a precise procedure that is time-saving, radiation-reducing, and relatively easy to use. Precise osteotomy and good short-term results were

  9. Improvement of the knee center of rotation during walking after opening wedge high tibial osteotomy.

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    Kim, Kyungsoo; Feng, Jun; Nha, Kyung Wook; Park, Won Man; Kim, Yoon Hyuk

    2015-06-01

    Accurate measurement of the center of rotation of the knee joint is indispensable for prediction of joint kinematics and kinetics in musculoskeletal models. However, no study has yet identified the knee center of rotations during several daily activities before and after high tibial osteotomy surgery, which is one surgical option for treating knee osteoarthritis. In this study, an estimation method for determining the knee joint center of rotation was developed by applying the optimal common shape technique and symmetrical axis of rotation approach techniques to motion-capture data and validated for typical activities (walking, squatting, climbing up stairs, walking down stairs) of 10 normal subjects. The locations of knee joint center of rotations for injured and contralateral knees of eight subjects with osteoarthritis, both before and after high tibial osteotomy surgery, were then calculated during walking. It was shown that high tibial osteotomy surgery improved the knee joint center of rotation since the center of rotations for the injured knee after high tibial osteotomy surgery were significantly closer to those of the normal healthy population. The difference between the injured and contralateral knees was also generally reduced after surgery, demonstrating increased symmetry. These results indicate that symmetry in both knees can be recovered in many cases after high tibial osteotomy surgery. Moreover, the recovery of center of rotation in the injured knee was prior to that of symmetry. This study has the potential to provide fundamental information that can be applied to understand abnormal kinematics in patients, diagnose knee joint disease, and design a novel implants for knee joint surgeries. © IMechE 2015.

  10. Reliability of the imaging software in the preoperative planning of the open-wedge high tibial osteotomy.

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    Lee, Yong Seuk; Kim, Min Kyu; Byun, Hae Won; Kim, Sang Bum; Kim, Jin Goo

    2015-03-01

    The purpose of this study was to verify a recently developed picture-archiving and communications system-photoshop method by comparing reliabilities between real-size paper template and the PACS-photoshop methods in preoperative planning of open-wedge high tibial osteotomy. A prospective case series was conducted, including patients with medial osteoarthritis undergoing open-wedge high tibial osteotomy. In the preoperative planning, the picture-archiving and communications system-photoshop method and real-size paper template method were used simultaneously in all patients. Preoperative hip-knee-ankle angle, height, and angle of the osteotomy were evaluated. The reliability of this newly devised method was evaluated, and the consistency between the two methods was also evaluated using intra-class correlation coefficient. Using the picture-archiving and communications system-photoshop method, the mean correction angle and height of osteotomy gap of rater-1 were 11.7° ± 3.6° and 10.7 ± 3.6 mm, respectively. The mean correction angle and height of osteotomy gap of rater-2 were 12.0 ± 2.6 and 10.8 ± 3.6, respectively. The inter- and intra-rater reliabilities of the correction angle were 0.956 ~ 0.979 and 0.980 ~ 0.992, respectively. The inter- and intra-rater reliabilities of the height of the osteotomy gap were 0.968 ~ 0.985 and 0.971 ~ 0.994, respectively (p photoshop method, mean values of the correction angle and height of the osteotomy gap were 11.9° ± 3.6° and 10.8 ± 3.6 mm, respectively. Consistency between the two methods by comparing the means of the correction angle and the height of the osteotomy gap were 0.985 and 0.985, respectively (p photoshop method enables direct measurement of the height of the osteotomy gap with high reliability.

  11. A predictive factor for acquiring an ideal lower limb realignment after opening-wedge high tibial osteotomy.

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    Bito, Haruhiko; Takeuchi, Ryohei; Kumagai, Ken; Aratake, Masato; Saito, Izumi; Hayashi, Riku; Sasaki, Yohei; Aota, Yoichi; Saito, Tomoyuki

    2009-04-01

    Obtaining a correct postoperative limb alignment is an important factor in achieving a successful clinical outcome after an opening-wedge high tibial osteotomy (OWHTO). To better predict some of the aspects that impact upon the clinical outcomes following this procedure, including postoperative correction loss and over correction, we examined the changes in the frontal plane of the lower limb in a cohort of patients who had undergone OWHTO using radiography. Forty-two knees from 33 patients (23 cases of osteoarthritis and 10 of osteonecrosis) underwent a valgus realignment OWHTO procedure and were radiographically assessed for changes that occurred pre- and post-surgery. The mean femorotibial angle (FTA) was found to be 182.1 +/- 2.0 degrees (12 +/- 2.0 anatomical varus angulation) preoperatively and 169.6 +/- 2.4 degrees (10.4 +/- 2.4 anatomical valgus angulation) postoperatively. These measurements thus revealed significant changes in the weight bearing line ratio (WBL), femoral axis angle (FA), tibial axis angle (TA), tibia plateau angle (TP), tibia vara angle (TV) and talar tilt angle (TT) following OWHTO. In contrast, no significant change was found in the weight bearing line angle (WBLA) after these treatments. To assess the relationship between the correction angle and these indexes, 42 knees were divided into the following three groups according to the postoperative FTA; a normal correction group (168 degrees FTA FTA FTA > 172 degrees ). There were significant differences in the delta angle [DA; calculated as (pre FTA - post FTA) - (pre TV - post TV)] among each group of patients. Our results thus indicate a negative correlation between the DA and preoperative TA (R(2) = 0.148, p < 0.05). Hence, given that the correction errors in our patients appear to negatively correlate with the preoperative TA, postoperative malalignments are likely to be predictable prior to surgery.

  12. EVALUATION OF FUNCTIONAL RESULTS OF MEDIAL OPENING WEDGE HIGH TIBIAL OSTEOTOMY FOR UNICOMPARTMENTAL OSTEOARTHRITIS VARUS KNEE

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    Shyam Sundar Bakki

    2017-01-01

    Full Text Available BACKGROUND Osteoarthritis commonly affects the medial compartment of knee giving rise to varus deformity in majority of cases. Significant varus deformity further aggravates the pathology due to medialisation of the weight bearing line osteotomy of the proximal tibia realigns this weight bearing axis, thereby relieving pressure on the damaged medial compartment. OWHTO is a promising option in this scenario because it is associated with high accuracy in correcting the deformity and less number of complications when compared to lateral closing wedge HTO or UKA. In this study, we evaluate the functional outcome of HTO in patients with unicompartmental osteoarthritis. MATERIALS AND METHODS This is a prospective study of patients who attended the orthopaedic outpatient clinic in Government Hospital, Kakinada, between August 2013 to August 2015. The patients were evaluated by clinical examination and weight bearing radiographs. The patients who were found to have unicompartmental osteoarthritis with knee pain not relieved by conservative management and who satisfy the inclusion criteria were selected. RESULTS Excellent results can be achieved by appropriate selection criteria and planning with long limb weight bearing radiographs. There is an excellent relief of pain, which can be achieved within first few months postoperatively, which is assessed by VAS score. The KSS- knee score is excellent in 35%, good in 40%, fair in 20% and poor in 5%. The KSS- function score is excellent in 30%, good in 45%, fair in 20% and poor in 5%. There is significant improvement in the range of movement of the knee joint postoperatively. CONCLUSION In this study, we conclude that medial OWHTO is the preferred modality for unicompartmental OA in those aged <60 years and in developing nations like India where squatting is an important function, it has major role as it can restore near normal knee function without disturbing anatomy.

  13. The value of the intra-operative clinical mechanical axis measurement in open-wedge valgus high tibial osteotomies

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    van de Pol, G.J.; Verdonschot, Nicolaas Jacobus Joseph; van Kampen, A.

    2012-01-01

    Introduction: In high tibial osteotomies (HTO) the correction needs to be precise and intra-operative assessment is essential. The purpose of this study was to evaluate the use of the intra-operative clinical mechanical axis measurement and compare it to the post-operative weight bearing situation

  14. [Combined closing-wedge high tibial osteotomy with arthroscopy for varus knee and medial compartment osteoarthritis: clinical results at a minimum follow-up for five years].

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    Liu, Jin-Song; Li, Zhi-Yao

    2013-09-01

    To study the results of closing-wedge high tibial osteotomy and arthroscopy for the treatment of medial compartment osteoarthritis of the knee. From October 2005 to June 2007, 25 patients met with our inclusion criteria. All the patients with medial compartment knee osteoarthritis were treated with arthroscopy and closing-wedge high tibial osteotomy. There were 11 males and 14 females,with a mean age of 53 years old. The pre-operative HSS knee score was 67.6 +/- 2.8, FTA was (185.54 +/- 1.11) degrees, and aLPTA was (96.54 +/- 0.52) degrees in average. The patients were followed up and evaluated according to HSS knee score. The efficacy of the osteotomy was evaluated by FTA and aLPTA. All surgeries were successful without serious complication. All the patients were followed up, and the duration ranged from 5 to 7 years. The HSS was 85.5 +/- 3.7 at the 1st year and 80.3 +/- 5.4 at the latest follow-up. There was significant difference between every two scores of before operation and the two after operation (t = -33.135, P = 0.000; t = -13.215, P = 0.000). The FTA was (173.65 +/- 0.92) degrees at the 1st year and (174.34 +/- 0.53) degrees at the latest follow-up. There was significant difference between every two angles of before operation and after operation (t = 28.739, P = 0.000; t = 2.331, P = 0.048). The aLPTA was (87.32 +/- 0.33) degrees at the 1st year and (87.67 +/- 2.82) degrees at the latest follow-up. There was significant difference between every two angles of before operation and after operation (t = 37.264, P = 0.000; t = 2.469, P = 0.039). Indication is important and good surgical technique is critical for good clinical outcome. A detailed plan before operation is essential for the operation. Arthroscopy is helpful for treating the intra-articular pathology. The osteoarthritis is still in progress but in a slow mode. The combined method of arthroscopy and closing-wedge high tibial osteotomy is a reliable way for medial compartment osteoarthritis of the

  15. Effect of open wedge high tibial osteotomy on the lateral tibiofemoral compartment in sheep. Part III: analysis of the microstructure of the subchondral bone and correlations with the articular cartilage and meniscus.

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    Ziegler, Raphaela; Goebel, Lars; Seidel, Roland; Cucchiarini, Magali; Pape, Dietrich; Madry, Henning

    2015-09-01

    First, to evaluate whether medial open wedge high tibial osteotomy (HTO) induces alterations of the microstructure of the lateral tibial subchondral bone plate of sheep. Second, to test the hypothesis that specific correlations exist between topographical structural alterations of the subchondral bone, the cartilage and the lateral meniscus. Three experimental groups received biplanar osteotomies of the right proximal tibiae: (a) closing wedge HTO (4.5° of tibial varus), (b) opening wedge HTO (4.5° tibial valgus; standard correction) and (c) opening wedge HTO (9.5° of valgus; overcorrection), each of which was compared to the non-osteotomised contralateral proximal tibiae. After 6 months, subchondral bone structure indices were measured by computed tomography. Correlations between the subchondral bone, the articular cartilage and the lateral meniscus were determined. Increased loading by valgus overcorrection led to an enlarged specific bone surface (BS/BV) in the subarticular spongiosa compared with unloading by varisation. The subchondral bone plate was 3.9-fold thicker in the central region of the lateral tibial plateau than in the submeniscal periphery. Its thickness in the central region significantly correlated with the thickness of the articular cartilage. In the submeniscal region, such correlation did not exist. In general, a higher degree of osteoarthritis (OA) correlated with alterations of the subchondral bone plate microstructure. OA of the submeniscal articular cartilage also correlated with worse matrix staining of the lateral meniscus. Osteoarthritis changes are associated with alterations of the subchondral bone plate microstructure. Specific topographical relationships exist in the central region between the articular cartilage and subchondral bone plate thickness, and in the submeniscal periphery between and the articular cartilage and lateral meniscus. From a clinical perspective, the combined follow-up data from this and the previous two

  16. Patellofemoral Osteoarthritis Progression and Alignment Changes after Open-Wedge High Tibial Osteotomy Do Not Affect Clinical Outcomes at Mid-term Follow-up.

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    Goshima, Kenichi; Sawaguchi, Takeshi; Shigemoto, Kenji; Iwai, Shintaro; Nakanishi, Akira; Ueoka, Ken

    2017-10-01

    To evaluate the clinical and radiological outcomes of open-wedge high tibial osteotomy (OWHTO) with respect to the patellofemoral joint and to assess whether patellofemoral osteoarthritis (OA) progression and alignment changes after OWHTO affect clinical outcomes. Inclusion criteria were consecutive patients who underwent OWHTO from March 2005 to September 2013. Exclusion criteria were loss to follow-up within 2 years and absence of second-look arthroscopy findings at the time of plate removal. The clinical parameters, including anterior knee pain while climbing stairs, Japanese Orthopedic Association score, and Oxford Knee Score, were evaluated. Radiological outcomes, including weight-bearing line ratio, modified Blackburne-Peel ratio, posterior tibial slope, tilting angle, lateral shift ratio, and patellofemoral OA (Kellgren-Lawrence grade), were evaluated preoperatively and at the final follow-up. Cartilage status (International Cartilage Repair Society grade) was evaluated at the initial HTO and at plate removal. Fifty-three patients (60 knees) were included in this study. The mean follow-up was 58.2 ± 22.4 months. Two knees (3%) presented with mild anterior knee pain after OWHTO. The mean Japanese Orthopedic Association score (66.9 ± 11.2 to 91.2 ± 9.7) significantly improved (P patellofemoral OA had progressed in 15 knees (27%), and arthroscopically patellofemoral cartilage degeneration had progressed in 27 knees (45%). However, there was no significant correlation between changes in patellofemoral alignment and clinical outcomes. Changes in patellofemoral alignment and patellofemoral OA progression did not affect the clinical outcomes of OWHTO at mid-term follow-up. Level IV, therapeutic case series. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  17. Clinical and radiographic outcomes of medial open-wedge high tibial osteotomy with Anthony-K plate: prospective minimum five year follow-up data.

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    Altay, Mehmet Akif; Ertürk, Cemil; Altay, Nuray; Mercan, Ahmet Şükrü; Sipahioğlu, Serkan; Kalender, Ali Murat; Işıkan, Uğur Erdem

    2016-07-01

    The purpose of this study was to prospectively evaluate the clinical and radiographic outcomes, and complication rates, after a minimum of five years of follow-up after medial open wedge high tibial osteotomy (MOWHTO) using an Anthony-K plate. MOWHTO was performed on 35 knees of 34 consecutive patients. A visual analogue scale (VAS), and Western Ontario and McMaster University Osteoarthritis (WOMAC) and Lysholm scores, were used in clinical evaluation. Upon radiographic assessment, alignment was expressed as the femorotibial angle (FTA). The posterior tibial slope (PTS) and the Insall-Salvati Index (ISI) were also measured. VAS, WOMAC, and Lysholm scores improved significantly upon follow-up (p FTA was 4.68 ± 4.39° varus pre-operatively; at the last post-operative follow-up, the value was 8.43 ± 2.02° valgus. The mean correction angle was 13.1 ± 2.7°. A significant increase in PTS was evident (p < 0.01), as was a significant decrease in the ISI (p < 0.01). The overall complication rate was 8.6 %. The Anthony-K plate affords accurate correction, initially stabilises the osteotomy after surgery, and maintains such stability until the osteotomy gap is completely healed, without correction loss. The plate survival rate was 97.2 % after a minimum of five years of follow-up. The plate increased the PTS, as do other medial osteotomy fixation plates.

  18. Total knee replacement for tricompartmental arthritis in a patient with a below-knee amputation after a previous closing wedge high tibial osteotomy

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    Mark A. Fleming, MBBCH, FC orth(SA, MMED

    2016-06-01

    Full Text Available This is a report of a 64-year-old man who had undergone a high tibial osteotomy (HTO 17 years ago of his right knee for medial compartment osteoarthritis; 5 days later, he received a below-knee amputation owing to a missed popliteal artery injury at the time of the HTO. We elected to perform a total knee replacement (TKR for progressive arthritis of the ipsilateral knee 17 years after the transtibial amputation. Although there is a plethora of literature regarding TKR in the contralateral knee of amputees, there is a paucity of data of TKR in the ipsilateral knee. Using medical search engines including Google Scholar and PubMed, we were only able to identify 4 case reports of TKR in the ipsilateral knee of below-knee amputees. This is the first description in the English literature that has the following rare pathology list: tricompartmental arthritis with a previous closing wedge HTO with a resultant truncated valgus tibia and short transtibial amputation.

  19. Role of an anatomically contoured plate and metal block for balanced stability between the implant and lateral hinge in open-wedge high-tibial osteotomy.

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    Jang, Young Woong; Lim, DoHyung; Seo, Hansol; Lee, Myung Chul; Lee, O-Sung; Lee, Yong Seuk

    2018-07-01

    Open-wedge high tibial osteotomy (OWHTO) is a well-established surgical option for medial compartment osteoarthritis of the varus knee. The initial strength of the fixation plate is critical for successful correction maintenance and healing of the osteotomy site. This study was conducted to verify if a newly designed anatomical plate (LCfit) improves the stability of both the medial implant and lateral hinge area, as well as to evaluate how the metal block contributes to both medial and lateral stability. A finite element (FE) tibial model was combined with TomoFix plate, a LCfit plate with and without a metal block. Data analysis was conducted to evaluate the balanced stability, which refers to the enforced lateral stability resulting from redistribution of overall stress. We assessed the balanced stability of the medial implant and lateral hinge area in three cases using the same Sawbones and loads using the tibia FE model. The LCfit plate reduced stress by 23.1% at the lateral hinge compared to the TomoFix plate (TomoFix vs. LCfit: 34.2 ± 23.3 MPa vs. 26.3 ± 17.5 MPa). The LCfit plate with a metal block reduced stress by 40.1% at the medial plate (210.1 ± 64.2 MPa vs. 125.8 ± 65.7 MPa) and by 31.2% (26.3 ± 17.5 MPa vs. 18.1 ± 12.1 MPa) at the lateral hinge area compared to the reduction using the LCfit plate without a metal block. The newly designed fixation system for OWHTO balanced the overall stress distribution and reduced stress at the lateral hinge area compared to that using a conventional fixation system. The addition of the metal block showed additional benefits for balanced stability between the medial implant and lateral hinge area. However, this conclusion could only be drawn using the FE model in this study. Therefore, further clinical studies are necessary to reveal the clinical effect of reduced lateral stress on the occurrence of the lateral hinge fracture and the biologic effect of the metal block on the

  20. Primary stability of different plate positions and the role of bone substitute in open wedge high tibial osteotomy.

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    Takeuchi, Ryohei; Woon-Hwa, Jung; Ishikawa, Hiroyuki; Yamaguchi, Yuichiro; Osawa, Katsunari; Akamatsu, Yasushi; Kuroda, Koichi

    2017-12-01

    The purpose of this study was to compare the mechanical fixation strengths of anteromedial and medial plate positions in osteotomy, and clarify the effects of bone substitute placement into the osteotomy site. Twenty-eight sawbone tibia models were used. Four different models were prepared: Group A, the osteotomy site was open and the plate position was anteromedial; Group B, bone substitutes were inserted into the osteotomy site and the plate position was anteromedial; Group C, the osteotomy site was open and the plate position was medial; and Group D, bone substitutes were inserted into the osteotomy site and the plate position was medial. The loading condition ranged from 0 to 800N and one hertz cycles were applied. Changes of the tibial posterior slope angle (TPS), stress on the plate and lateral hinge were measured. The changes in the TPS and the stress on the plate were significantly larger in Group A than in Group C. These were significantly larger in Group A than in Group B, and in Group C than in Group D. There was no significant difference between Group B and Group D, and no significant difference between knee flexion angles of 0° and 10°. Stress on the lateral hinge was significantly smaller when bone substitute was used. A medial plate position was biomechanically superior to an anteromedial position if bone substitute was not used. Bone substitute distributed the stress concentration around the osteotomy gap and prevented an increase in TPS angle regardless of the plate position. Copyright © 2017. Published by Elsevier B.V.

  1. Mid-term survival analysis of closed wedge high tibial osteotomy: A comparative study of computer-assisted and conventional techniques.

    Science.gov (United States)

    Bae, Dae Kyung; Song, Sang Jun; Kim, Kang Il; Hur, Dong; Jeong, Ho Yeon

    2016-03-01

    The purpose of the present study was to compare the clinical and radiographic results and survival rates between computer-assisted and conventional closing wedge high tibial osteotomies (HTOs). Data from a consecutive cohort comprised of 75 computer-assisted HTOs and 75 conventional HTOs were retrospectively reviewed. The Knee Society knee and function scores, Hospital for Special Surgery (HSS) score and femorotibial angle (FTA) were compared between the two groups. Survival rates were also compared with procedure failure. The knee and function scores at one year postoperatively were slightly better in the computer-assisted group than those in conventional group (90.1 vs. 86.1) (82.0 vs. 76.0). The HSS scores at one year postoperatively were slightly better for the computer-assisted HTOs than those of conventional HTOs (89.5 vs. 81.8). The inlier of the postoperative FTA was wider in the computer-assisted group than that in the conventional HTO group (88.0% vs. 58.7%), and mean postoperative FTA was greater in the computer-assisted group that in the conventional HTO group (valgus 9.0° vs. valgus 7.6°, pclinical and radiographic results were better in the computer-assisted group that those in the conventional HTO group. Mid-term survival rates did not differ between computer-assisted and conventional HTOs. A comparative analysis of longer-term survival rate is required to demonstrate the long-term benefit of computer-assisted HTO. III. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Satisfactory functional and radiological outcomes can be expected in young patients under 45 years old after open wedge high tibial osteotomy in a long-term follow-up.

    Science.gov (United States)

    Hantes, Michael E; Natsaridis, Prodromos; Koutalos, Antonios A; Ono, Yohei; Doxariotis, Nikolaos; Malizos, Konstantinos N

    2017-11-30

    To report the long-term outcomes of medial open wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis in patients younger than 45 years old. It was hypothesized that the correction of knee alignment would result in preservation of knee function in a long-term follow-up. Patients under 45 years old, who underwent MOWHTO for symptomatic medial compartment knee osteoarthritis between 2001 and 2005 were retrospectively reviewed after a minimum of 10 years. The osteotomy was performed utilizing a locking plate without the use of bone graft. Patients were evaluated pre- and postoperatively using the International Knee Documentation Committee Score, the Oxford Knee Score, the Knee injury Osteoarthritis Outcome Score and the Short Form-12 Score. Standardized standing whole-limb radiographs were also obtained to assess mechanical tibiofemoral angle (mTFA) and the grade of osteoarthritis. A total of 20 patients (18 males, 2 females, mean age 35.4 years) with a mean follow-up of 12.3 years were included in the study. During the follow-up period, one patient required conversion to total knee replacement (95% survival rate). All clinical outcome scores (IKDC, KOOS, OKS, and SF-12) significantly improved postoperatively (p satisfactory and the survival rate is 95%, 12 years after the procedure. Level IV therapeutic, retrospective, cohort study.

  3. Patella height changes post high tibial osteotomy

    Directory of Open Access Journals (Sweden)

    Siew Ghim Gooi

    2017-01-01

    Full Text Available Background: Medial opening wedge high tibial osteotomy (HTO is a well-described treatment in early medial compartmental osteoarthritis of the knee. However, two undesirable sequelae may follow –patella baja and changes in the posterior tibial slope (TS. Materials and Methods: We conducted a retrospective study in patients who underwent HTO in our center between September 2009 and February 2017. Preoperative and 6-week postoperative long-leg weight bearing films and lateral knee radiographs were assessed. Pre- and postoperative radiological measurements include the Caton-Deschamps Index (CDI, the mechanical axis deviation (MAD, and the posterior TS. Independant t-test and Pearson correlation test were performed. Results: A total of 106 knees were recruited. The mean age was 48.8 ± 10.8 years. 66 (62.3% and 40 (37.7% knees were from males and females, respectively. The mean pre- and postoperative measurements was (−9.70° ± 3.67° to 0.08° ± 2.80° (−varus; +valgus for the MAD, (7.14° ± 1.78° to 8.72° ± 3.11° for posterior TS, and (0.93° ± 0.084° to 0.82° ± 0.13° for CDI (P ≤ 0.001 for all. The association between patella height change and the level of osteotomy (supra-tubercle vs. infra-tubercle was statistically significant (P < 0.001. A supra-tubercle osteotomy cut significantly lowering patella height (P = 0.011. There was otherwise no statistically significant correlations between patella height changes and the correction angle (P = 0.187 or posterior TS change (P = 0.744. Conclusions: A medial opening wedge HTO above the tibial tubercle was significantly associated with lowering patella height or reducing CDI postoperatively. Based on our results, we would recommend the use of an infra-tubercle osteotomy during the corrective surgery to prevent the complication of patella baja.

  4. Monoplanar versus biplanar medial open-wedge proximal tibial osteotomy for varus gonarthrosis: a comparison of clinical and radiological outcomes.

    Science.gov (United States)

    Elmalı, Nurzat; Esenkaya, Irfan; Can, Murat; Karakaplan, Mustafa

    2013-12-01

    We compared clinical and radiological results of two proximal tibial osteotomy (PTO) techniques: monoplanar medial open-wedge osteotomy and biplanar retrotubercle medial open-wedge osteotomy, stabilised by a wedged plate. We evaluated 88 knees in 78 patients. Monoplanar medial open-wedge PTO was performed on 56 knees in 50 patients with a mean age of 55 ± 9 years. Biplanar retrotubercle medial open-wedge PTO was performed on 32 knees in 28 patients with a mean age of 57 ± 7 years. Mean follow-up periods were 40.6 ± 7 months for the monoplanar PTO group and 38 ± 5 months for the biplanar retrotubercle PTO group. Clinical outcome was evaluated using the hospital for special surgery scoring system, and radiological outcome was evaluated by the measurements of femorotibial angle (FTA), patellar height and tibial slope changes. In both groups, post-operative HSS scores increased significantly. No significant difference was found between groups in FTA alteration, but the FTA decreased significantly in both groups. Patellar index ratios decreased significantly in the monoplanar PTO group (Insall-Salvati Index by 0.07, Blackburne-Peel Index by 0.07), but not in the biplanar retrotubercle PTO group. Tibial slopes were increased significantly in the monoplanar PTO group, but not in the retrotubercle PTO group. Biplanar retrotubercle medial open-wedge osteotomy and monoplanar medial open-wedge osteotomy are both clinically effective for the treatment for varus gonarthrosis. Retrotubercle osteotomy also prevents patella infera and tibial slope changes radiologically.

  5. Differences between opening versus closing high tibial osteotomy on clinical outcomes and gait analysis.

    Science.gov (United States)

    Deie, Masataka; Hoso, Takayuki; Shimada, Noboru; Iwaki, Daisuke; Nakamae, Atsuo; Adachi, Nobuo; Ochi, Mitsuo

    2014-12-01

    High tibial osteotomy (HTO) for medial knee osteoarthritis (OA) is mainly performed via two procedures: closing wedge HTO (CW) and opening wedge HTO (OW). In this study, differences between these procedures were assessed by serial clinical evaluation and gait analysis before and after surgery. Twenty-one patients underwent HTO for medial knee OA in 2011 and 2012, with 12 patients undergoing CW and nine undergoing OW. The severity of OA was classified according to the Kellgren-Lawrence classification. The Japanese Orthopedic Association score for assessment of knee OA (JOA score), the Numeric Rating Scale (NRS), and the femoral tibial angle (FTA) on X-ray were evaluated. For gait analysis, gait speed, varus moment, varus angle and lateral thrust were calculated. The JOA score and NRS were improved significantly one year postoperatively in both groups. The FTA was maintained in both groups at one year. Varus angle and varus moment were significantly improved in both groups at each postoperative follow-up, when compared preoperatively. Lateral thrust was significantly improved at three months postoperatively in both groups. However, the significant improvement in lateral thrust had disappeared in the CW group six months postoperatively, whereas it was maintained for at least one year in the OW group. This study found that clinical outcomes were well maintained after HTO. OW reduced knee varus moment and lateral thrust, whereas CW had little effect on reducing lateral thrust. Level IV. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The preclinical sheep model of high tibial osteotomy relating basic science to the clinics: standards, techniques and pitfalls.

    Science.gov (United States)

    Pape, Dietrich; Madry, Henning

    2013-01-01

    To develop a preclinical large animal model of high tibial osteotomy to study the effect of axial alignment on the lower extremity on specific issues of the knee joint, such as in articular cartilage repair, development of osteoarthritis and meniscal lesions. Preoperative planning, surgical procedure and postoperative care known from humans were adapted to develop a HTO model in the adult sheep. Thirty-five healthy, skeletally mature, female Merino sheep between 2 and 4 years of age underwent a HTO of their right tibia in a medial open-wedge technique inducing a normal (group 1) and an excessive valgus alignment (group 2) and a closed-wedge technique (group 3) inducing a varus alignment with the aim of elucidating the effect of limb alignment on cartilage repair in vivo. Animals were followed up for 6 months. Solid bone healing and maintenance of correction are most likely if the following surgical principles are respected: (1) medial and longitudinal approach to the proximal tibia; (2) biplanar osteotomy to increase initial rotatory stability regardless of the direction of correction; (3) small, narrow but long implant with locking screws; (4) posterior plate placement to avoid slope changes; (5) use of bicortical screws to account for the brittle bone of the tibial head and to avoid tibial head displacement. Although successful high tibial osteotomy in sheep is complex, the sheep may--because of its similarities with humans--serve as an elegant model to induce axial malalignment in a clinically relevant environment, and osteotomy healing under challenging mechanical conditions.

  7. High-resolution axial MR imaging of tibial stress injuries

    Directory of Open Access Journals (Sweden)

    Mammoto Takeo

    2012-05-01

    Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

  8. High-resolution axial MR imaging of tibial stress injuries

    Science.gov (United States)

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  9. The Effect of Malrotation of Tibial Component of Total Knee Arthroplasty on Tibial Insert during High Flexion Using a Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Kei Osano

    2014-01-01

    Full Text Available One of the most common errors of total knee arthroplasty procedure is a malrotation of tibial component. The stress on tibial insert is closely related to polyethylene failure. The objective of this study is to analyze the effect of malrotation of tibial component for the stress on tibial insert during high flexion using a finite element analysis. We used Stryker NRG PS for analysis. Three different initial conditions of tibial component including normal, 15° internal malrotation, and 15° external malrotation were analyzed. The tibial insert made from ultra-high-molecular-weight polyethylene was assumed to be elastic-plastic while femoral and tibial metal components were assumed to be rigid. Four nonlinear springs attached to tibial component represented soft tissues around the knee. Vertical load was applied to femoral component which rotated from 0° to 135° while horizontal load along the anterior posterior axis was applied to tibial component during flexion. Maximum equivalent stresses on the surface were analyzed. Internal malrotation caused the highest stress which arose up to 160% of normal position. External malrotation also caused higher stress. Implanting prosthesis in correct position is important for reducing the risk of abnormal wear and failure.

  10. Change in gait after high tibial osteotomy: A systematic review and meta-analysis.

    Science.gov (United States)

    Lee, Seung Hoon; Lee, O-Sung; Teo, Seow Hui; Lee, Yong Seuk

    2017-09-01

    We conducted a meta-analysis to analyze how high tibial osteotomy (HTO) changes gait and focused on the following questions: (1) How does HTO change basic gait variables? (2) How does HTO change the gait variables in the knee joint? Twelve articles were included in the final analysis. A total of 383 knees was evaluated. There were 237 open wedge (OW) and 143 closed wedge (CW) HTOs. There were 4 level II studies and 8 level III studies. All studies included gait analysis and compared pre- and postoperative values. One study compared CWHTO and unicompartmental knee arthroplasty (UKA), and another study compared CWHTO and OWHTO. Five studies compared gait variables with those of healthy controls. One study compared operated limb gait variables with those in the non-operated limb. Gait speed, stride length, knee adduction moment, and lateral thrust were major variables assessed in 2 or more studies. Walking speed increased and stride length was increased or similar after HTO compared to the preoperative value in basic gait variables. Knee adduction moment and lateral thrust were decreased after HTO compared to the preoperative knee joint gait variables. Change in co-contraction of the medial side muscle after surgery differed depending on the degree of frontal plane alignment. The relationship between change in knee adduction moment and change in mechanical axis angle was controversial. Based on our systematic review and meta-analysis, walking speed and stride length increased after HTO. Knee adduction moment and lateral thrust decreased after HTO compared to the preoperative values of gait variables in the knee joint. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Anterior tibial stress fractures treated with anterior tension band plating in high-performance athletes.

    Science.gov (United States)

    Cruz, Alexandre Santa; de Hollanda, João Paris Buarque; Duarte, Aires; Hungria Neto, José Soares

    2013-06-01

    The non-surgical treatment of anterior tibial cortex stress fractures requires long periods of abstention from sports activities and often results in non-union. Many different surgical techniques have already been previously described to treat these fractures, but there is no consensus on the best treatment. We describe the outcome of treatment using anterior tibial tension band plating in three high-performance athletes (4 legs) with anterior tibial cortex stress fractures. Tibial osteosynthesis with a 3.5-mm locking compression plate in the anterolateral aspect of the tibia was performed in all patients diagnosed with anterior tibial stress fracture after September 2010 at Santa Casa Hospital. All of the fractures were consolidated within a period of 3 months after surgery, allowing for an early return to pre-injury levels of competitive sports activity. There were no infection, non-union, malunion or anterior knee pain complications. Anterior tibial tension band plating leads to prompt fracture consolidation and is a good alternative for the treatment of anterior tibial cortex stress fractures. Bone grafts were shown to be unnecessary.

  12. The influence of wedge diffuser blade number and divergence angle on the performance of a high pressure ratio centrifugal compressor

    Science.gov (United States)

    Wang, Yi; Han, Ge; Lu, Xingen; Zhu, Junqiang

    2018-02-01

    Wedge diffuser is widely used in centrifugal compressors due to its high performance and compact size. This paper is aimed to research the influence of wedge diffuser blade number and divergence angle on centrifugal compressor performance. The impact of wedge diffuser blade number on compressor stage performance is investigated, and then the wedge diffusers with different divergence angle are studied by varying diffuser wedge angle and blade number simultaneously. It is found that wedge diffuser with 27 blades could have about 0.8% higher adiabatic efficiency and 0.14 higher total pressure ratio than the wedge diffuser with 19 blades and the best compressor performance is achieved when diffuser divergence angle is 8.3°.These results could give some advices on centrifugal compressor design.

  13. Wedge Splitting Test on Fracture Behaviour of Fiber Reinforced and Regular High Performance Concretes

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2013-01-01

    The fracture behaviour of three fiber reinforced and regular High Performance Concretes (HPC) is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix developed by CONTEC ApS (Denmark). The wedge splitting test setup with 48 cubical specimens...

  14. High resolution ultrasonography of the tibial nerve in diabetic peripheral neuropathy.

    Science.gov (United States)

    Singh, Kunwarpal; Gupta, Kamlesh; Kaur, Sukhdeep

    2017-12-01

    High-resolution ultrasonography of the tibial nerve is a fast and non invasive tool for diagnosis of diabetic peripheral neuropathy. Our study was aimed at finding out the correlation of the cross sectional area and maximum thickness of nerve fascicles of the tibial nerve with the presence and severity of diabetic peripheral neuropathy. 75 patients with type 2 diabetes mellitus clinically diagnosed with diabetic peripheral neuropathy were analysed, and the severity of neuropathy was determined using the Toronto Clinical Neuropathy Score. 58 diabetic patients with no clinical suspicion of diabetic peripheral neuropathy and 75 healthy non-diabetic subjects were taken as controls. The cross sectional area and maximum thickness of nerve fascicles of the tibial nerves were calculated 3 cm cranial to the medial malleolus in both lower limbs. The mean cross sectional area (22.63 +/- 2.66 mm 2 ) and maximum thickness of nerve fascicles (0.70 mm) of the tibial nerves in patients with diabetic peripheral neuropathy compared with both control groups was significantly larger, and statistically significant correlation was found with the Toronto Clinical Neuropathy Score ( p peripheral neuropathy had a larger mean cross sectional area (14.40 +/- 1.72 mm 2 ) and maximum thickness of nerve fascicles of the tibial nerve (0.40 mm) than healthy non-diabetic subjects (12.42 +/- 1.01 mm 2 and 0.30 mm respectively). The cross sectional area and maximum thickness of nerve fascicles of the tibial nerve is larger in diabetic patients with or without peripheral neuropathy than in healthy control subjects, and ultrasonography can be used as a good screening tool in these patients.

  15. Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy.

    Science.gov (United States)

    Hernigou, Philippe; Huys, Maxime; Pariat, Jacques; Roubineau, François; Flouzat Lachaniette, Charles Henri; Dubory, Arnaud

    2018-02-01

    There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy. We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically. The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis. Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile

  16. Traumatic Dislodgement of Tibial Polyethylene Insert after a High-Flex Posterior-Stabilized Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Juan Felix Astoul Bonorino

    2015-01-01

    Full Text Available Many pathologic entities can produce a painful total knee replacement (TKR that may lead to potential prosthetic failure. Polyethylene insert dissociation from the tibial baseplate has been described most frequently after mobile-bearing and cruciate-retaining TKRs. However, only 3 tibial insert dislocations in primary fixed-bearing High-Flex posterior-stabilized TKRs have been reported. We present a new case of tibial insert dislocation in a High-Flex model that shares similarities and differences with the cases reported, facilitating the analysis of the potential causes, which still remain undefined.

  17. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges.

    Science.gov (United States)

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-05-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10(-3) S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10(-1) S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front.

  18. Three Years of High Resolution Year-Round Monitoring of Ice-Wedge Thermal Contraction Cracking in Svalbard

    Science.gov (United States)

    Christiansen, H. H.

    2006-12-01

    Most likely ice-wedges are the most widespread periglacial landform in lowlands with continuous permafrost. With a changing climate it is important to understand better the geomorphological processes controlling ice- wedge growth and decay, as they might cause large changes to the surface of the landscape, particularly if the active layer thickness increases causing melting of the most ice-rich permafrost top layer. As most settlements on permafrost are located in lowland areas, ice-wedge formation can also influence the infrastructure. Understanding the processes of ice-wedge growth and their thaw transformation into ice-wedge casts are essential when using contemporary ice wedges as analogues of Pleistocene thermal contraction cracking in palaeoenvironmental reconstructions. As ice-wedges are largely controlled by winter conditions, improved understanding of the factors controlling their growth will enable better palaeoclimatic reconstructions both directly from ice-wedges, but also from ice-wedge casts, than just mean winter temperatures. Detailed studies of ice-wedge dynamics, including quantification of movement, have only been done in very few places in the Arctic. In high arctic Svalbard at 78°N climate at sea level locates these islands close to the southern limit of the continuous permafrost zone, with MAAT of as much as -4 to -6°C. However, thermal contraction cracking is demonstrated to be widespread in the Adventdalen study area in Svalbard. The year-round field access from the University Centre in Svalbard, UNIS, has enabled the collection of different continuous or high frequency ice-wedge process monitoring data since 2002 to improve the understanding of the geomorphological activity of this landform. In all the winters the air temperature was below -30°C for shorter or longer periods. During all the winters, the temperature in the top permafrost was below -15°C both in the ice-wedge top for shorter or longer periods. The snow cover was

  19. Open-wedge osteotomy using an internal plate fixator in patients with medial-compartment gonarthritis and varus malalignment

    DEFF Research Database (Denmark)

    Niemeyer, Philipp; Schmal, Hagen; Hauschild, Oliver

    2010-01-01

    PURPOSE: Our purpose was to evaluate the 3-year clinical results of patients with medial-compartment osteoarthritis of the knee and varus malalignment who underwent open-wedge high tibial osteotomy (HTO) with an internal plate fixator (TomoFix; Synthes, Solothurn, Switzerland). Clinical results a...

  20. The effect of platelet-rich plasma on osseous healing in dogs undergoing high tibial osteotomy.

    Directory of Open Access Journals (Sweden)

    Samuel P Franklin

    Full Text Available The purpose of this study was to investigate whether platelet-rich plasma (PRP enhances osseous healing in conjunction with a high tibial osteotomy in dogs.Randomized controlled trial.Sixty-four client-owned pet dogs with naturally occurring rupture of the anterior cruciate ligament and that were to be treated with a high tibial osteotomy (tibial plateau leveling osteotomy were randomized into the treatment or control group. Dogs in the treatment group received autologous platelet-rich plasma activated with calcium chloride and bovine thrombin to produce a well-formed PRP gel that was placed into the osteotomy at the time of surgery. Dogs in the control group received saline lavage of the osteotomy. All dogs had the osteotomy stabilized with identical titanium alloy implants and all aspects of the surgical procedure and post-operative care were identical among dogs of the two groups. Bone healing was assessed at exactly 28, 49, and 70 days after surgery with radiography and ultrasonography and with MRI at day 28. The effect of PRP on bone healing was assessed using a repeated measures analysis of covariance with radiographic and ultrasonographic data and using a t-test with the MRI data.Sixty dogs completed the study. There were no significant differences in age, weight, or gender distribution between the treatment and control groups. Twenty-seven dogs were treated with PRP and 33 were in the control group. The average platelet concentration of the PRP was 1.37x106 platelets/μL (±489x103 with a leukocyte concentration of 5.45x103/μL (±3.5x103. All dogs demonstrated progressive healing over time and achieved clinically successful outcomes. Time since surgery and patient age were significant predictors of radiographic healing and time since surgery was a significant predictor of ultrasonographic assessment of healing. There was no significant effect of PRP treatment as assessed radiographically, ultrasonographically, or with MRI.The PRP used

  1. Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes.

    Science.gov (United States)

    Zbeda, Robert M; Sculco, Peter K; Urch, Ekaterina Y; Lazaro, Lionel E; Borens, Olivier; Williams, Riley J; Lorich, Dean G; Wellman, David S; Helfet, David L

    2015-07-01

    Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures. Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing. Case series; Level of evidence, 4. Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition. Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion. Anterior tension band plating for chronic tibial stress

  2. Wedges I

    International Nuclear Information System (INIS)

    DeWitt-Morette, C.; Low, S.G.; Schulman, L.S.; Shiekh, A.Y.

    1986-01-01

    The wedge problem, that is, the propagation of radiation or particles in the presence of a wedge, is examined in different contexts. Generally, the paper follows the historical order from Sommerfeld's early work to recent stochastic results - hindsights and new results being woven in as appropriate. In each context, identifying the relevant mathematical problem has been the key to the solution. Thus each section can be given both a physics and a mathematics title: Section 2: diffraction by reflecting wedge; boundary value problem of differential equations; solutions defined on multiply connected spaces. Section 3: geometrical theory of diffraction; identification of function spaces. Section 4: path integral solutions; path integration on multiply connected spaces; asymptotics on the boundaries of function spaces. Section 5: probing the shape of the wedge and the roughness of its surface; stochastic calculus. Several propagators and Green functions are given explicitly, some old ones and some new ones. They include the knife-edge propagator for Dirichlet and Neumann boundary conditions, the absorbing knife edge propagator, the wedge propagators, the propagator for a free particle on a /sigma phi/-sheeted Riemann surface, the Dirichlet and the Neumann wedge Green function

  3. Wedge Splitting Test and Inverse Analysis on Fracture Behaviour of Fiber Reinforced and Regular High Performance Concretes

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2014-01-01

    The fracture behaviour of three fiber reinforced and regular HPC (high performance concretes) is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix developed by CONTEC ApS (Denmark). The wedge splitting test setup with 48 cubical specimens...

  4. Anterior tension band plating for anterior tibial stress fractures in high-performance female athletes: a report of 4 cases

    NARCIS (Netherlands)

    Borens, Olivier; Sen, Milan K.; Huang, Russel C.; Richmond, Jeffrey; Kloen, Peter; Jupiter, Jesse B.; Helfet, David L.

    2006-01-01

    Stress fracture of the anterior tibial cortex is an extremely challenging fracture to treat, especially in the high-performance female athlete who requires rapid return to competition. Previous reports have not addressed treating these fractures in the world-class athlete with anterior plating. We

  5. Combined Anterior Cruciate Ligament Reconstruction and High Tibial Osteotomy in Anterior Cruciate Ligament-Deficient Varus Knees

    Directory of Open Access Journals (Sweden)

    Ayman M. Ebied

    2017-12-01

    Conclusion: The combined procedure of ACL reconstruction and high tibial osteotomy restored knee stability and reduced pain over the medial compartment. Although the combined procedure has a longer period of rehabilitation than an isolated ACL reconstruction, the elimination of lateral thrust and preservation of articular cartilage of the medial compartment are of paramount importance to the future of these knees.

  6. Prediction of microstructure and ductile damage of a high-speed railway axle steel during cross wedge rolling

    OpenAIRE

    Huo, Y; Lin, J; Bai, Q; Wang, B; Tang, X; Ji, H

    2016-01-01

    Microstructure and ductile damage have a significant influence on the deformation behavior of high-speed railway axles during hot cross wedge rolling (CWR) and its final performance. In this study, based on the continuum damage mechanics, a multiaxial constitutive model coupling microstructure and ductile damage was established to predict the evolution of microstructure and ductile damage of 25CrMo4 during hot CWR processes. Material constants within the multiaxial constitutive model were det...

  7. High Rate of Recurrence Following Proximal Medial Opening Wedge Osteotomy for Correction of Moderate Hallux Valgus.

    Science.gov (United States)

    Iyer, Sravisht; Demetracopoulos, Constantine A; Sofka, Carolyn M; Ellis, Scott J

    2015-07-01

    The proximal medial opening wedge (PMOW) osteotomy has become more popular to treat moderate to severe hallux valgus with the recent development of specifically designed, low-profile modular plates. Despite the promising results previously reported in the literature, we have noted a high incidence of recurrence in patients treated with a PMOW. The purpose of this study was to report the clinical and radiographic outcomes of an initial cohort of patients treated with a PMOW osteotomy for moderate hallux valgus. We retrospectively analyzed prospectively gathered data on a cohort of 17 consecutive patients who were treated by the senior author using a PMOW osteotomy for moderate hallux valgus deformity. Average time to follow-up was 2.4 years (range, 1.0-3.5 years). The intermetatarsal angle (IMA), the hallux valgus angle (HVA), and the distal metatarsal articular angle (DMAA) were assessed on standard weightbearing radiographs of the foot preoperatively and at all follow-up visits. The Foot and Ankle Outcome Score (FAOS) was collected on all patients preoperatively and at final follow-up. Despite demonstrating good correction of their deformity initially, 11 of the 17 patients (64.7%) had evidence of recurrence of their hallux valgus deformity at final follow-up. Patients who recurred had a greater preoperative HVA (P = .023) and DMAA (P = .049) than patients who maintained their correction. Improvement in the quality-of-life subscale of the FAOS was noted at final follow-up for all patients (P = .05). There was no significant improvement in any of the other FAOS subscales. There was a high rate of recurrence of the hallux valgus deformity in this cohort of patients. Recurrence was associated with greater preoperative deformity and an increased preoperative DMAA. The PMOW without a concomitant distal metatarsal osteotomy may be best reserved for patients with mild hallux valgus deformity without an increased DMAA. Level IV, retrospective case series. © The Author

  8. Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review

    NARCIS (Netherlands)

    Mallee, Wouter H.; Weel, Hanneke; van Dijk, C. Niek; van Tulder, Maurits W.; Kerkhoffs, Gino M.; Lin, Chung-Wei Christine

    2015-01-01

    To compare surgical and conservative treatment for high-risk stress fractures of the anterior tibial cortex, navicular and proximal fifth metatarsal. Systematic searches of CENTRAL, MEDLINE, EMBASE, CINAHL, SPORTDiscus and PEDro were performed to identify relevant prospective and retrospective

  9. Long-term outcomes of wedge resection at the limbus for high irregular corneal astigmatism after repaired corneal laceration

    Directory of Open Access Journals (Sweden)

    Jun Du

    2016-06-01

    Full Text Available AIM: To evaluate the clinical value of wedge resection at corneal limbus in patients with traumatic corneal scarring and high irregular astigmatism. METHODS: Patients with traumatic corneal astigmatism received wedge resection at least 6mo after suture removal from corneal wound. The uncorrected distance visual acuities (UCVA and best corrected distance visual acuities (BCVA, pre- and post-operation astigmatism, spherical equivalent (SE, safety and complications were evaluated. RESULTS: Ten eyes (10 patients were enrolled in this study. Mean follow-up time after wedge resection was 37.8±15.4mo (range, 20-61mo. The mean UCVA improved from +1.07±0.55 logMAR to +0.43±0.22 logMAR (P=0.000 and the mean BCVA from +0.50±0.30 logMAR to +0.15±0.17 logMAR (P=0.000. The mean astigmatism power measured by retinoscopy was -2.03±2.27 D postoperatively and -2.83±4.52 D preoperatively (P=0.310. The mean SE was -0.74±1.61 D postoperatively and -0.64±1.89 D preoperatively (P=0.601. Two cases developed mild pannus near the sutures. No corneal perforation, infectious keratitis or wound gape occurred. CONCLUSION: Corneal-scleral limbal wedge resection with compression suture is a safe, effective treatment for poor patients with high irregular corneal astigmatism after corneal-scleral penetrating injury. Retinoscopy can prove particularly useful for high irregular corneal astigmatism when other measurements are not amenable.

  10. Rethinking wedges

    Science.gov (United States)

    Davis, Steven J.; Cao, Long; Caldeira, Ken; Hoffert, Martin I.

    2013-03-01

    Abstract Stabilizing CO2 emissions at current levels for fifty years is not consistent with either an atmospheric CO2 concentration below 500 ppm or global temperature increases below 2 °C. Accepting these targets, solving the climate problem requires that emissions peak and decline in the next few decades, and ultimately fall to near zero. Phasing out emissions over 50 years could be achieved by deploying on the order of 19 'wedges', each of which ramps up linearly over a period of 50 years to ultimately avoid 1 GtC y-1 of CO2 emissions. But this level of mitigation will require affordable carbon-free energy systems to be deployed at the scale of tens of terawatts. Any hope for such fundamental and disruptive transformation of the global energy system depends upon coordinated efforts to innovate, plan, and deploy new transportation and energy systems that can provide affordable energy at this scale without emitting CO2 to the atmosphere. 1. Introduction In 2004, Pacala and Socolow published a study in Science arguing that '[h]umanity can solve the carbon and climate problem in the first half of this century simply by scaling up what we already know how to do' [1]. Specifically, they presented 15 options for 'stabilization wedges' that would grow linearly from zero to 1 Gt of carbon emissions avoided per year (GtC y-1 1 Gt = 1012 kg) over 50 years. The solution to the carbon and climate problem, they asserted, was 'to deploy the technologies and/or lifestyle changes necessary to fill all seven wedges of the stabilization triangle'. They claimed this would offset the growth of emissions and put us on a trajectory to stabilize atmospheric CO2 concentration at 500 ppm if emissions decreased sharply in the second half of the 21st century. The wedge concept has proven popular as an analytical tool for considering the potential of different technologies to reduce CO2 emissions. In the years since the paper was published, it has been cited more than 400 times, and

  11. Medial tibial stress syndrome in high school cross-country runners: incidence and risk factors.

    Science.gov (United States)

    Plisky, Melody S; Rauh, Mitchell J; Heiderscheit, Bryan; Underwood, Frank B; Tank, Robert T

    2007-02-01

    Prospective cohort. To determine (1) the cumulative seasonal incidence and overall injury rate of medial tibial stress syndrome (MTSS) and (2) risk factors for MTSS with a primary focus on the relationship between navicular drop values and MTSS in high school cross-country runners. MTSS is a common injury among runners. However, few studies have reported the injury rate and risk factors for MTSS among adolescent runners. Data collected included measurement of bilateral navicular drop and foot length, and a baseline questionnaire regarding the runner's height, body mass, previous running injury, running experience, and orthotic or tape use. Runners were followed during the season to determine athletic exposures (AEs) and occurrence of MTSS. The overall injury rate for MTSS was 2.8/1000 AEs. Although not statistically different, girls had a higher rate (4.3/1000 AEs) than boys (1.7/1000 AEs) (P = .11). Logistic regression modeling indicated that only gender and body mass index (BMI) were significantly associated with the occurrence of MTSS. However, when controlled for orthotic use, only BMI was associated with risk of MTSS. No significant associations were found between MTSS and navicular drop or foot length. Our findings suggest that navicular drop may not be an appropriate measure to identify runners who may develop MTSS during a cross-country season; thus, additional studies are needed to identify appropriate preseason screening tools.

  12. Imaging of posterior tibial tendon dysfunction—Comparison of high-resolution ultrasound and 3 T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldner, Michael A., E-mail: michael.arnoldner@meduniwien.ac.at [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria); Gruber, Michael [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria); Syré, Stefanie [Medical University of Vienna, Vienna General Hospital, Department of Trauma-Surgery, Währinger Gürtel 18-20, 1090 Vienna (Austria); Kristen, Karl-Heinz [Foot & Ankle Centre Vienna, Alser Straße 43/8, 1080 Vienna (Austria); Trnka, Hans-Jörg [Foot & Ankle Centre Vienna, Alser Straße 43/8, 1080 Vienna (Austria); Orthopaedic Hospital Vienna, Speisinger Straße 109, 1130 Vienna (Austria); Kainberger, Franz; Bodner, Gerd [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria)

    2015-09-15

    Highlights: • 18 MHz high-resolution ultrasound appears to be slightly more accurate than 3 T MRI in the diagnosis of PTTD. • High-resolution ultrasound is recommended as an initial diagnostic tool. • Long-lasting PTT discomfort may require MRI. • Other pathologies can mimic PTTD. - Abstract: Purpose: Posterior tibial tendon dysfunction is the most common cause of acquired asymmetric flatfoot deformity. The purpose of this study was to determine and compare the diagnostic value of MRI and high-resolution ultrasound (HR-US) in posterior tibial tendon dysfunction (PTTD), and assess their correlation with intraoperative findings. Materials and methods: We reviewed 23 posterior tibial tendons in 23 patients with clinical findings of PTTD (13 females, 10 males; mean age, 50 years) with 18 MHz HR-US and 3 T MRI. Surgical intervention was performed in nine patients. Results: HR-US findings included 2 complete tears, 6 partial tears, 10 tendons with tendinosis, and 5 unremarkable tendons. MRI demonstrated 2 complete tears, 7 partial tears, 10 tendons with tendinosis, and 4 unremarkable tendons. HR-US and MRI were concordant in 20/23 cases (87%). Image findings for HR-US were confirmed in six of nine patients (66.7%) by intraoperative inspection, whereas imaging findings for MRI were concordant with five of nine cases (55.6%). Conclusion: Our results indicate that HR-US can be considered slightly more accurate than MRI in the detection of PTTD.

  13. Imaging features of iBalance, a new high tibial osteotomy: what the radiologist needs to know.

    Science.gov (United States)

    Alaia, Erin FitzGerald; Burke, Christopher J; Alaia, Michael J; Strauss, Eric J; Ciavarra, Gina A; Rossi, Ignacio; Rosenberg, Zehava Sadka

    2017-01-01

    To describe the post-surgical imaging appearance and complications of high tibial osteotomy in patients with the iBalance implant system (iHTO; Arthrex, Naples, FL, USA). Retrospective, institutional review board-approved, Health Insurance Portability and Accountability Act-compliant review of imaging after 24 iBalance procedures was performed with attention to: correction of varus malalignment, healing at the osteotomy site, resorption of the osteoinductive compound, and complications. Immediate correction of the varus deformity was present in all cases. Lobular radiolucency was present in all cases, more pronounced on the lateral knee radiograph, simulating infection or erosive disease. Four radiographic signs of healing were observed: blurring at the opposing osteotomy bony margins and at the osteoinductive compound and the adjacent bone interface, callus formation, and resorption of the osteoinductive compound. Complications were present in 33 % of cases, including fracture through the lateral tibial cortex (21 %), genu varum recurrence (8 %), painful exuberant bone formation (4 %), persistent pain, requiring total knee arthroplasty (4 %), and non-union (after >6 months' follow-up), with suspected infection (4 %). Radiologists should be aware of the normal radiographic appearance following iBalance high tibial osteotomy, which may be confused with infection. Radiologists should also be aware of potential post-operative complications and compare all post-operative radiographs with the immediate post-operative examination to detect collapse of the osteotomy site and recurrence of varus angulation.

  14. Wedged multilayer Laue lens

    International Nuclear Information System (INIS)

    Conley, Ray; Liu Chian; Qian Jun; Kewish, Cameron M.; Macrander, Albert T.; Yan Hanfei; Maser, Joerg; Kang, Hyon Chol; Stephenson, G. Brian

    2008-01-01

    A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures

  15. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  16. Treatment of open tibial fracture with bone defect caused by high velocity missiles: A case report

    Directory of Open Access Journals (Sweden)

    Golubović Zoran

    2013-01-01

    Full Text Available Introduction .Tibia fracture caused by high velocity missiles is mostly comminuted and followed by bone defect which makes their healing process extremely difficult and prone to numerous complications. Case Outline. A 34-year-old male was wounded at close range by a semi-automatic gun missile. He was wounded in the distal area of the left tibia and suffered a massive defect of the bone and soft tissue. After the primary treatment of the wound, the fracture was stabilized with an external fixator type Mitkovic, with convergent orientation of the pins. The wound in the medial region of the tibia was closed with the secondary stitch, whereas the wound in the lateral area was closed with the skin transplant after Thiersch. Due to massive bone defect in the area of the rifle-missile wound six months after injury, a medical team placed a reconstructive external skeletal fixator type Mitkovic and performed corticotomy in the proximal metaphyseal area of the tibia. By the method of bone transport (distractive osteogenesis, the bone defect of the tibia was replaced. After the fracture healing seven months from the secondary surgery, the fixator was removed and the patient was referred to physical therapy. Conclusion. Surgical treatment of wounds, external fixation, performing necessary debridement, adequate antibiotic treatment and soft and bone tissue reconstruction are essential in achieving good results in patients with the open tibial fracture with bone defect caused by high velocity missiles. Reconstruction of bone defect can be successfully treated by reconstructive external fixator Mitkovic. [Projekat Ministarstva nauke Republike Srbije, br. III 41017 i br. III 41004

  17. Analysis of Outcomes for High Tibial Osteotomies Performed With Cartilage Restoration Techniques.

    Science.gov (United States)

    Kahlenberg, Cynthia A; Nwachukwu, Benedict U; Hamid, Kamran S; Steinhaus, Michael E; Williams, Riley J

    2017-02-01

    To evaluate reported medium- to long-term outcomes after high tibial osteotomy (HTO) with associated cartilage restoration procedures. A review of the MEDLINE database was performed. The inclusion criteria were English language, clinical outcome study with HTO as the primary procedure, use of a form of cartilage repair included, and the mean follow-up period of at least 2 years. Each identified study was reviewed for study design, patient demographics, type of procedures performed, clinical outcomes, progression to total knee arthroplasty, and complications. Eight hundred and twenty-seven patients (839 knees) were included. The most common cartilage preservation technique used in conjunction with HTO was microfracture (4 studies; 22.2%). The mean Lyscholm scores, reported in 50% of the studies, ranged from 40 to 65.7 preoperatively and improved to a range of 67 to 94.6 postoperatively. Four studies (22.2%) used a visual analog scale for evaluation of pain and all had a mean visual analog scale of less than 3 postoperatively. Among studies evaluating conversion to arthroplasty, the rate of conversion was 6.8% and the range of mean number of years from HTO to conversion was 4.9 to 13.0. The overall reported complication rate was 10.3%. HTO with cartilage restoration procedures provides reliable improvement in functional status in the medium- to long-term period after surgery and has potential to delay or avoid the need for knee arthroplasty surgery. Level IV, systematic review of Level I to IV studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  18. Increased cartilage volume after injection of hyaluronic acid in osteoarthritis knee patients who underwent high tibial osteotomy.

    Science.gov (United States)

    Chareancholvanich, Keerati; Pornrattanamaneewong, Chaturong; Narkbunnam, Rapeepat

    2014-06-01

    High tibial osteotomy (HTO) is a surgical procedure used to correct abnormal mechanical loading of the knee joint; additionally, intra-articular hyaluronic acid injections have been shown to restore the viscoelastic properties of synovial fluid and balance abnormal biochemical processes. It was hypothesized that combining HTO with intra-articular hyaluronic acid injections would have benefit to improve the cartilage volume of knee joints. Forty patients with medial compartment knee osteoarthritis (OA) were randomly placed into 1 of 2 groups. The study group (n = 20) received 2 cycles (at 6-month intervals) of 5 weekly intra-articular hyaluronic acid injections after HTO operation. The control group (n = 20) did not receive any intra-articular injections after HTO surgery. Cartilage volume (primary outcome) was assessed by magnetic resonance imaging (MRI) pre-operatively and 1 year post-operatively. Treatment efficacy (secondary outcomes) was evaluated with the Western Ontario and McMaster Universities OA Index (WOMAC) and by the comparison of the total rescue medication (paracetamol/diclofenac) used (weeks 6, 12, 24, 48). MRI studies showed a significant increase in total cartilage volume (p = 0.033), lateral femoral cartilage volume (p = 0.044) and lateral tibial cartilage volume (p = 0.027) in the study group. Cartilage volume loss was detected at the lateral tibial plateau in the control group. There were significant improvements after surgery in both groups for all subscales of WOMAC scores (p hyaluronic acid injections may be beneficial for increasing total cartilage volume and preventing the loss of lateral tibiofemoral joint cartilage after HTO. Therapeutic study, Level I.

  19. Greenhouse Gas Dynamics in a Salt-Wedge Estuary Revealed by High Resolution Cavity Ring-Down Spectroscopy Observations.

    Science.gov (United States)

    Tait, Douglas R; Maher, Damien T; Wong, WeiWen; Santos, Isaac R; Sadat-Noori, Mahmood; Holloway, Ceylena; Cook, Perran L M

    2017-12-05

    Estuaries are an important source of greenhouse gases to the atmosphere, but uncertainties remain in the flux rates and production pathways of greenhouse gases in these dynamic systems. This study performs simultaneous high resolution measurements of the three major greenhouse gases (carbon dioxide, methane, and nitrous oxide) as well as carbon stable isotope ratios of carbon dioxide and methane, above and below the pycnocline along a salt wedge estuary (Yarra River estuary, Australia). We identified distinct zones of elevated greenhouse gas concentrations. At the tip of salt wedge, average CO 2 and N 2 O concentrations were approximately five and three times higher than in the saline mouth of the estuary. In anaerobic bottom waters, the natural tracer radon ( 222 Rn) revealed that porewater exchange was the likely source of the highest methane concentrations (up to 1302 nM). Isotopic analysis of CH 4 showed a dominance of acetoclastic production in fresh surface waters and hydrogenotrophic production occurring in the saline bottom waters. The atmospheric flux of methane (in CO 2 equivalent units) was a major (35-53%) contributor of atmospheric radiative forcing from the estuary, while N 2 O contributed <2%. We hypothesize that the release of bottom water gases when stratification episodically breaks down will release large pulses of greenhouse gases to the atmosphere.

  20. Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review

    NARCIS (Netherlands)

    Mallee, W.H.; Weel, H.; van Dijk, C.N.; van Tulder, M.W.; Kerkhoffs, G.M.; Lin, C.W.C.

    2015-01-01

    Aim To compare surgical and conservative treatment for high-risk stress fractures of the anterior tibial cortex, navicular and proximal fifth metatarsal. Methods Systematic searches of CENTRAL, MEDLINE, EMBASE, CINAHL, SPORTDiscus and PEDro were performed to identify relevant prospective and

  1. [Tibial periostitis ("medial tibial stress syndrome")].

    Science.gov (United States)

    Fournier, Pierre-Etienne

    2003-06-01

    Medial tibial stress syndrome is characterised by complaints along the posteromedial tibia. Runners and athletes involved in jumping activities may develop this syndrome. Increased stress to stabilize the foot especially when excessive pronation is present explain the occurrence this lesion.

  2. Portal dosimetry in wedged beams

    NARCIS (Netherlands)

    Spreeuw, Hanno; Rozendaal, Roel; Camargo, Priscilla; Mans, Anton; Wendling, Markus; Olaciregui-Ruiz, Igor; Sonke, Jan-Jakob; van Herk, Marcel; Mijnheer, Ben

    2015-01-01

    Portal dosimetry using electronic portal imaging devices (EPIDs) is often applied to verify high-energy photon beam treatments. Due to the change in photon energy spectrum, the resulting dose values are, however, not very accurate in the case of wedged beams if the pixel-to-dose conversion for the

  3. Association between knee alignment and knee pain in patients surgically treated for medial knee osteoarthritis by high tibial osteotomy. A one year follow-up study

    DEFF Research Database (Denmark)

    W-Dahl, Annette; Toksvig-Larsen, Sören; Roos, Ewa

    2009-01-01

    on for knee OA by high tibial osteotomy. METHODS: 182 patients (68% men) mean age 53 years (34 - 69) with varus alignment having tibial osteotomy by the hemicallotasis technique for medial knee OA were consecutively included. Knee alignment was assessed by the Hip-Knee-Ankle (HKA) angle from radiographs...... including the hip and ankle joints. Knee pain was measured by the subscale pain (0 - 100, worst to best scale) of the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at one year follow-up. To estimate the association between knee alignment and knee pain multivariate regression...... with every degree of HKA angle, adjusted analysis 0.3 points (95% CI -1.3 - 0.6).The mean postoperative knee alignment was 184 degrees (171 - 185). The mean change in knee alignment was 13 degrees (0 - 30). The mean change in KOOS pain was 32 (-16 - 83). There was neither any association between change...

  4. Measurement of hepatic venous pressure gradient revisited: Catheter wedge vs balloon wedge techniques

    Directory of Open Access Journals (Sweden)

    S Timothy Chelliah

    2011-01-01

    Full Text Available Aims: To evaluate the accuracy of measurement of hepatic venous pressure gradient by catheter wedge as compared to balloon wedge (the gold standard. Materials and Methods: Forty-five patients having a clinical diagnosis of intrahepatic portal hypertension were subjected to the two different types of pressure measurements (catheter wedge and balloon wedge during transjugular liver biopsy under fluoroscopic guidance. Statistical Analysis: Spearman′s rank correlation coefficient, Bland-Altman plot for agreement, and single measure intraclass correlation were used for analysis of data. Results: There was a close correlation between the results obtained by both the techniques, with highly significant concordance (P < 0.0001. Hepatic venous pressure gradients as measured by the catheter wedge technique were either equal to or less than those obtained by the balloon wedge technique. Conclusions: The difference in hepatic venous pressure gradients measured by the two techniques is insignificant.

  5. Modelling the wedge shape for the virtual wedge

    International Nuclear Information System (INIS)

    Chang Liyun; Ho Shengyow; Chen, Helen H W

    2003-01-01

    We present a method to model the virtual wedge shape in a 3D treatment planning system as a physical wedge. The virtual wedge shape was determined using the measured dose profile of the virtual wedge at a chosen reference depth. The differences between the calculated and the measured dose profiles for the virtual wedge were within 0.5% at the reference depth, and within 2.5% at other depths. This method provides a fast and accurate way to implement the virtual wedge into our planning system for any wedge angles. This method is also applicable to model the physical wedge shapes with comparable good results

  6. Tibial valgus aperture osteotomy

    International Nuclear Information System (INIS)

    De los Rios G, Adolfo Leon; Saavedra Abadia, Adolfo Leon; Palacios, Julio

    2005-01-01

    This study is based on work carried out a The knee clinic at the arthroscopic surgery unit of the Institute of osteo-articular diseases, Imbanaco Medical Centre, The University Hospital of the Valle (Cali-Colombia) and The Fractures Clinic Ltd. (Palmira-Valle). This is a descriptive study, which demonstrates very positive outcomes for aperture osteotomy, without detracting from the importance of, and the progress made in uni-compartmental and total joint articular replacements of the knee. 10 patients were treated with a highs tibial open osteotomy between November 1988 and December 2002: 3 had post-traumatic deformities, without arthrosic alterations; 1 had pseudo-arthrosis caused by a failed corrective procedure; 1 had complex instability of the knee with osseous varus; 6 had a degenerative lesion of the medial meniscus with medial condral alterations. Follow-up was form 12 to 54 months. Treatment involved a tibial valgus aperture osteotomy and osteo-synthesis. Evaluation was carried out using the International Knee Documentation Committee (IKDC) scale, the For Special Surgery and The Knee Society Score

  7. Effect and safety of early weight-bearing on the outcome after open-wedge high tibial osteotomy: a systematic review and meta-analysis.

    Science.gov (United States)

    Lee, O-Sung; Ahn, Soyeon; Lee, Yong Seuk

    2017-07-01

    The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of early weight-bearing by comparing clinical and radiological outcomes between early and traditional delayed weight-bearing after OWHTO. A rigorous and systematic approach was used. The methodological quality was also assessed. Results that are possible to be compared in two or more than two articles were presented as forest plots. A 95% confidence interval was calculated for each effect size, and we calculated the I 2 statistic, which presents the percentage of total variation attributable to the heterogeneity among studies. The random-effects model was used to calculate the effect size. Six articles were included in the final analysis. All case groups were composed of early full weight-bearing within 2 weeks. All control groups were composed of late full weight-bearing between 6 weeks and 2 months. Pooled analysis was possible for the improvement in Lysholm score, but there was no statistically significant difference shown between groups. Other clinical results were also similar between groups. Four studies reported mechanical femorotibial angle (mFTA) and this result showed no statistically significant difference between groups in the pooled analysis. Furthermore, early weight-bearing showed more favorable results in some radiologic results (osseointegration and patellar height) and complications (thrombophlebitis and recurrence). Our analysis supports that early full weight-bearing after OWHTO using a locking plate leads to improvement in outcomes and was comparable to the delayed weight-bearing in terms of clinical and radiological outcomes. On the contrary, early weight-bearing was more favorable with respect to some radiologic parameters and complications compared with delayed weight-bearing.

  8. CyberKnife with tumor tracking: An effective alternative to wedge resection for high-risk surgical patients with stage I non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Sean eCollins

    2012-02-01

    Full Text Available Published data suggests that wedge resection for stage I NSCLC results in improved overall survival compared to stereotactic body radiation therapy (SBRT. We report CyberKnife outcomes for high-risk surgical patients with biopsy-proven stage I NSCLC. PET/CT imaging was completed for staging. Three-to-five gold fiducial markers were implanted in or near tumors to serve as targeting references. Gross tumor volumes (GTVs were contoured using lung windows; the margins were expanded by 5 mm to establish the planning treatment volume (PTV. Treatment plans were designed using hundreds of pencil beams. Doses delivered to the PTV ranged from 42-60 Gy in 3 fractions. The 30-Gy isodose contour extended at least 1cm from the GTV to eradicate microscopic disease. Treatments were delivered using the CyberKnife system with tumor tracking. Examination and PET/CT imaging occurred at 3-month follow-up intervals. Forty patients (median age 76 with a median maximum tumor diameter of 2.6 cm (range, 1.4-5.0 cm and a mean post-bronchodilator percent predicted forced expiratory volume in 1 second (FEV1 of 57% (range, 21 - 111% were treated. A mean dose of 50 Gy was delivered to the PTV over 3 to 13 days (median, 7 days. The 30-Gy isodose contour extended a mean 1.9 cm from the GTV. At a median 44 months (range, 12 -72 months follow-up, the 3-year Kaplan-Meier locoregional control and overall survival estimates compare favorably with contemporary wedge resection outcomes at 91% and 75% , respectively. CyberKnife is an effective treatment approach for stage I NSCLC that is similar to wedge resection, eradicating tumors with 1 to 2 cm margins in order to preserve lung function. Prospective randomized trials comparing CyberKnife with wedge resection are necessary to confirm equivalence.

  9. Physical characteristics comparison of virtual wedge device with physical wedge

    International Nuclear Information System (INIS)

    Cho, Jung Keun; Choi, Kye Sook; Lim, Cheong Hwan; Kim, Jeong Koo; Jung, Hong Ryang; Lee, Jung Ok; Lee, Man Goo

    2001-01-01

    We compared the characteristics of Siemens virtual wedge device with physical wedges for clinical application. We investigated the characteristics of virtual and physical wedges for various wedge angles (15, 30, 45, and 60) using 6- and 15- MV photon beams. Wedge factors were measured in water using an ion chamber for various field sizes and depths. In case of virtual wedge device, as upper jaw moves during irradiation, wedge angles were estimated by accumulated doses. These measurements were performed at off-axis points perpendicular to the beam central axis in water for a 15 cm x 20 cm radiation field size at the depth of 10 cm. Surface does without and with virtual or physical wedges were measured using a parallel plate ion chamber at surface. Field size was 15 cm * 20 cm and a polystyrene phantom was used. For various field sizes, virtual and physical wedge factors were changed by maximum 2.1% and 3.9%, respectively. For various depths, virtual and physical wedge factors were changed by maximum 1.9% and 2.9%, respectively. No major difference was found between the virtual and physical wedge angles and the difference was within 0.5. Surface dose with physical wedge was reduced by maximum 20% (x-ray beam : 6 MV, wedge angle : 45, SSD : 80 cm) relative to one with virtual wedge or without wedge. Comparison of the characteristics of Siemens virtual wedge device with physical wedges was performed. Depth dependence of virtual wedge factor was smaller than that of physical wedge factor. Virtual and physical wedge factors were nearly independent of field sizes. The accuracy of virtual and physical wedge angles was excellent. Surface dose was found to be reduced using a physical wedge

  10. Physical characteristics comparison of virtual wedge device with physical wedge

    International Nuclear Information System (INIS)

    Choi, Dong Rak; Shin, Kyung Hwan; Lee, Kyu Chan; Kim, Dae Yong; Ahn, Yong Chan; Lim, Do Hoon; Kim, Moon Kyung; Huh, Seung Jae

    1999-01-01

    We have compared the characteristics of Siemens virtual wedge device with physical wedges for clinical application. We investigated the characteristics of virtual and physical wedges for various wedge angles (15, 30, 45, and 60 ) using 6- and 15MV photon beams. Wedge factors were measured in water using an ion chamber for various field sizes and depths. In case of virtual wedge device, as upper jaw moves during irradiation, wedge angles were estimated by accumulated doses. These measurements were performed at off-axis points perpendicular to the beam central axis in water for a 15 cm x 20 cm radiation field size at the depth of 10 cm. Surface doses without and with virtual or physical wedges were measured using a parallel plate ion chamber at surface. Field size was 15 cm x 20 cm and a polystyrene phantom was used. For various field sizes, virtual and physical wedge factors were changed by maximum 2.1% and 3.9%, respectively. For various depths, virtual and physical wedge factors were changed by maximum 1.9% and 2.9%, respectively. No major difference was found between the virtual and physical wedge angles and the difference was within 0.5 .deg. . Surface dose with physical wedge was reduced by maximum 20% (x-ray beam: 6 MV, wedge angle: 45 .deg. , SSD: 80cm) relative to one with virtual wedge or without wedge. Comparison of the characteristics of Siemens virtual wedge device with physical wedges was performed. Depth dependence of virtual wedge factor was smaller than that of physical wedge factor. Virtual and physical wedge factors were nearly independent of field sizes. The accuracy of virtual and physical wedge angles was excellent. Surface dose was found to be reduced using physical wedge

  11. Fraturas do planalto tibial Tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Maurício Kfuri Júnior

    2009-01-01

    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  12. A developed wedge fixtures assisted high precision TEM samples pre-thinning method: Towards the batch lamella preparation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2017-04-01

    Full Text Available Ion milling, wedge cutting or polishing, and focused ion beam (FIB milling are widely-used techniques for the transmission electron microscope (TEM sample preparation. Especially, the FIB milling provides a site-specific analysis, deposition, and ablation of materials in the micrometer and nanometer scale. However, the cost of FIB tools has been always a significant concern. Since it is inevitable to use the FIB technique, the improvement of efficiency is a key point. Traditional TEM sample preparation with FIB was routinely implemented on a single sample each time. Aiming at cost efficiency, a new pre-thinning technique for batch sample preparation was developed in this paper. The present proposal combines the sample preparation techniques with multi-samples thinning, cross-section scanning electron microscopy (SEM, wedge cutting, FIB and other sample pre-thinning techniques. The new pre-thinning technique is to prepare an edge TEM sample on a grinding and polishing fixture with a slant surface. The thickness of the wedges sample can be measured to 1∼2 μm under optical microscope. Therefore, this fixture is superior to the traditional optical method of estimating the membrane thickness. Moreover, by utilizing a multi-sample holding fixture, more samples can be pre-thinned simultaneously, which significantly improved the productivity of TEM sample preparation.

  13. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  14. Wedges of Anxiety

    DEFF Research Database (Denmark)

    Hellström, Maria; Brandt, Eva

    2005-01-01

    The Heraclitian notion of a reality in constant flux seems to have settled even in the public consciousness. We are, to an ever-increasing extent, on the move; in motion between different places of abode, between domiciles and places of residence, between temporary addresses and provisory settlem...... cones of light, as the cut their way into the unknown, like wedges of anxiety...

  15. High electron mobility through the edge states in random networks of c-axis oriented wedge-shaped GaN nanowalls grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Bhasker, H. P.; Dhar, S.; Sain, A.; Kesaria, Manoj; Shivaprasad, S. M.

    2012-01-01

    Transport and optical properties of random networks of c-axis oriented wedge-shaped GaN nanowalls grown spontaneously on c-plane sapphire substrates through molecular beam epitaxy are investigated. Our study suggests a one dimensional confinement of carriers at the top edges of these connected nanowalls, which results in a blue shift of the band edge luminescence, a reduction of the exciton-phonon coupling, and an enhancement of the exciton binding energy. Not only that, the yellow luminescence in these samples is found to be completely suppressed even at room temperature. All these changes are highly desirable for the enhancement of the luminescence efficiency of the material. More interestingly, the electron mobility through the network is found to be significantly higher than that is typically observed for GaN epitaxial films. This dramatic improvement is attributed to the transport of electrons through the edge states formed at the top edges of the nanowalls.

  16. Importance of tibial slope for stability of the posterior cruciate ligament deficient knee.

    Science.gov (United States)

    Giffin, J Robert; Stabile, Kathryne J; Zantop, Thore; Vogrin, Tracy M; Woo, Savio L-Y; Harner, Christopher D

    2007-09-01

    Previous studies have shown that increasing tibial slope can shift the resting position of the tibia anteriorly. As a result, sagittal osteotomies that alter slope have recently been proposed for treatment of posterior cruciate ligament (PCL) injuries. Increasing tibial slope with an osteotomy shifts the resting position anteriorly in a PCL-deficient knee, thereby partially reducing the posterior tibial "sag" associated with PCL injury. This shift in resting position from the increased slope causes a decrease in posterior tibial translation compared with the PCL-deficient knee in response to posterior tibial and axial compressive loads. Controlled laboratory study. Three knee conditions were tested with a robotic universal force-moment sensor testing system: intact, PCL-deficient, and PCL-deficient with increased tibial slope. Tibial slope was increased via a 5-mm anterior opening wedge osteotomy. Three external loading conditions were applied to each knee condition at 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 120 degrees of knee flexion: (1) 134-N anterior-posterior (A-P) tibial load, (2) 200-N axial compressive load, and (3) combined 134-N A-P and 200-N axial loads. For each loading condition, kinematics of the intact knee were recorded for the remaining 5 degrees of freedom (ie, A-P, medial-lateral, and proximal-distal translations, internal-external and varus-valgus rotations). Posterior cruciate ligament deficiency resulted in a posterior shift of the tibial resting position to 8.4 +/- 2.6 mm at 90 degrees compared with the intact knee. After osteotomy, tibial slope increased from 9.2 degrees +/- 1.0 degrees in the intact knee to 13.8 degrees +/- 0.9 degrees. This increase in slope reduced the posterior sag of the PCL-deficient knee, shifting the resting position anteriorly to 4.0 +/- 2.0 mm at 90 degrees. Under a 200-N axial compressive load with the osteotomy, an additional increase in anterior tibial translation to 2.7 +/- 1.7 mm at 30 degrees was

  17. Recognition and characterization of networks of water bodies in the Arctic ice-wedge polygonal tundra using high-resolution satellite imagery

    Science.gov (United States)

    Skurikhin, A. N.; Gangodagamage, C.; Rowland, J. C.; Wilson, C. J.

    2013-12-01

    Arctic lowland landscapes underlain by permafrost are often characterized by polygon-like patterns such as ice-wedge polygons outlined by networks of ice wedges and complemented with polygon rims, troughs, shallow ponds and thermokarst lakes. Polygonal patterns and corresponding features are relatively easy to recognize in high spatial resolution satellite imagery by a human, but their automated recognition is challenging due to the variability in their spectral appearance, the irregularity of individual trough spacing and orientation within the patterns, and a lack of unique spectral response attributable to troughs with widths commonly between 1 m and 2 m. Accurate identification of fine scale elements of ice-wedge polygonal tundra is important as their imprecise recognition may bias estimates of water, heat and carbon fluxes in large-scale climate models. Our focus is on the problem of identification of Arctic polygonal tundra fine-scale landscape elements (as small as 1 m - 2 m width). The challenge of the considered problem is that while large water bodies (e.g. lakes and rivers) can be recognized based on spectral response, reliable recognition of troughs is more difficult. Troughs do not have unique spectral signature, their appearance is noisy (edges are not strong), their width is small, and they often form connected networks with ponds and lakes, and thus they have overlapping spectral response with other water bodies and surrounding non-water bodies. We present a semi-automated approach to identify and classify Arctic polygonal tundra landscape components across the range of spatial scales, such as troughs, ponds, river- and lake-like objects, using high spatial resolution satellite imagery. The novelty of the approach lies in: (1) the combined use of segmentation and shape-based classification to identify a broad range of water bodies, including troughs, and (2) the use of high-resolution WorldView-2 satellite imagery (with resolution of 0.6 m) for this

  18. Clinical Application of Wedge Factor

    International Nuclear Information System (INIS)

    Choi, Dong Rak; Ahn, Yong Chan; Huh, Sueng Jae

    1995-01-01

    Purpose : In general. The wedge factors which are used clinical practices are ignored of dependency on field sizes and depths. In this present, we investigated systematically the depth and field size dependency to determine the absorbed dose more accurately. Methods : The wedge factors for each wedge filter were measured at various depth (depth of Dmax, 5cm, 10cm, and 15cm) and field sizes (5 X 5cm, 10 X 10cm, 15 X 15cm, 20 X 20 cm) by using 4-,6-, and 10-MV X rays. By convention, wedge factors are determined by taking the ratio of the central axis ionization readings when the wedge filter is in place to those of the open field in same field size and measurement depth. In this present work, we determined the wedge factors for 4-, 6-, and 10-MV X rays from Clinac 600C and 2100C linear accelerators (manufactured by Varian Associates, Inc., Palo Alto, CA). To confirm that the wedge was centered., measurements were done with the two possible wedge position and various collimator orientations. Results : The standard deviations of measured values are within 0.3% and the depth dependence of wedge factor is greater for the lower energies. Especially, the variation of wedge factor is no less than 5% for 4- and 6- MV X rays with more than 45 .deg. wedge filter. But there seems to be a small dependence on field size. Conclusion : The results of this study show a dependence on the point of measurement. There also seems to be a small dependence on field size. And so, we should consider the depth and field size dependence in determining the wedge factors. If one wedge factor were to be used for each wedge filter, it seems that the measurement for a 10cm X 10cm field size at a depth of 10cm would be a reasonable choice

  19. Diffraction by an immersed elastic wedge

    CERN Document Server

    Croisille, Jean-Pierre

    1999-01-01

    This monograph presents the mathematical description and numerical computation of the high-frequency diffracted wave by an immersed elastic wave with normal incidence. The mathematical analysis is based on the explicit description of the principal symbol of the pseudo-differential operator connected with the coupled linear problem elasticity/fluid by the wedge interface. This description is subsequently used to derive an accurate numerical computation of diffraction diagrams for different incoming waves in the fluid, and for different wedge angles. The method can be applied to any problem of coupled waves by a wedge interface. This work is of interest for any researcher concerned with high frequency wave scattering, especially mathematicians, acousticians, engineers.

  20. Decarbonization Wedges. November 2015. Report

    International Nuclear Information System (INIS)

    Alazard-Toux, N.; Criqui, P.; Devezeaux de Lavergne, J.G.; Chevallet, L.; Gentier, S.; Hache, E.; Le Net, E.; Menanteau, Ph.; Thais, Fr.; Achard, JL.; Allard, Fr.; Authier, O.; Babarit, A.; Badin, Fr.; Bazile, F.; Bernard, O.; Birat, JP.; Brault, P.; Burnol, A.; Carre, Fr.; Delrue, F.; Dufour, A.; Duplan, JL.; Durand, P.; Duval, O.; Fabriol, H.; Ferrant, P.; Flamant, G.; Forti, L.; Garnier, J.; Gimenez, M.; Goyeneche, O.; Hadj Said, N.; Jasserand, Fr.; Kalaydjian, F.; Le Boulluec, M.; Legrand, J.; Lorne, D.; Lucchese, P.; Magand, S.; Malbranche, Ph.; Mermillod, N.; Monot, F.; Olivier, B.; Pacaud, P.; Papillon, Ph.; Ponsot-Jacquin, C.; Quenard, D.; Rachez, X.; Rapin, M.; Rocher, Ph.; Sanjuan, B.; Sauvant-Moynot, V.; Tilagone, R.; Vinot, S.; Berthomieu, R.; Vajnovszki, A.

    2015-01-01

    2015 is a particularly eventful year in the field of energy. From 30 November through 11 December, France will host the 21. Conference of the Parties on Climate Change (COP21) in Paris. The expectations for this international event are high. Its main goal is to obtain an agreement to keep global warming below 2 deg. C by securing a set of voluntary commitments from the various countries and regions of the world to reduce global greenhouse gas emissions and by mobilizing $100 billion per year from 2020 onwards to finance climate change policies, especially in developing countries. In France, the year 2015 was also marked by the adoption of the Energy Transition and Green Growth Act that set a course and defined a road-map, through a set of objectives, aimed at helping our country reduce its CO 2 emissions in the field of energy. In this context, ANCRE (French National Alliance for Energy Research Coordination) would like to reiterate the major role of energy research and innovation in reducing anthropogenic (i.e. human induced) greenhouse gas emissions through research conducted on decarbonization wedges, a key technology in the fight against climate change in the field of energy on a planetary scale. Limiting the temperature increase on the earth's surface to 2 deg. C by 2100 is a challenging target, but it could be achievable with the rapid, sustained development and wide dissemination of a broad set of technologies. However, to achieve this goal, it is indispensable to conduct research aimed at speeding up low carbon technologies deployment and at reducing their cost. Through this joint report to which numerous researchers and experts contributed, ANCRE wishes to continue its efforts to build a global strategic vision that an Alliance comprising nearly 19 different research institutions can provide. This study follows the work conducted on energy transition scenarios for France and the road-maps drawn up by the ten programmatic groups structuring the

  1. Wedge silicon detectors for the inner trackering system of CMS

    International Nuclear Information System (INIS)

    Catacchini, E.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Meschini, M.; Parrini, G.; Pieri, M.; Wheadon, R.

    1997-01-01

    One ''wedge'' double sided silicon detector prototype for the CMS forward inner tracker has been tested both in laboratory and on a high energy particle beam. The results obtained indicate the most reliable solutions for the strip geometry of the junction side. Three different designs of ''wedge'' double sided detectors with different solutions for the ohmic side strip geometry are presented. (orig.)

  2. Modification of the cranial closing wedge ostectomy technique for the treatment of canine cruciate disease. Description and comparison with standard technique.

    Science.gov (United States)

    Wallace, A M; Addison, E S; Smith, B A; Radke, H; Hobbs, S J

    2011-01-01

    To describe a modification of the cranial closing wedge ostectomy (CCWO) technique and to compare its efficacy to the standard technique on cadaveric specimens. The standard and modified CCWO technique were applied to eight pairs of cadaveric tibiae. The following parameters were compared following the ostectomy: degrees of plateau levelling achieved (degrees), tibial long axis shift (degrees), reduction in tibial length (mm), area of bone wedge removed (cm²), and the area of proximal fragment (cm²). The size of the removed wedge of bone and the reduction in tibial length were significantly less with the modified CCWO technique. The modified CCWO has two main advantages. Firstly a smaller wedge is removed, allowing a greater preservation of bone stock in the proximal tibia, which is advantageous for implant placement. Secondly, the tibia is shortened to a lesser degree, which might reduce the risk of recurvatum, fibular fracture and patella desmitis. These factors are particularly propitious for the application of this technique to Terrier breeds with excessive tibial plateau angle, where large angular corrections are required. The modified CCWO is equally effective for plateau levelling and results in an equivalent tibial long-axis shift. A disadvantage with the modified technique is that not all of the cross sectional area of the distal fragment contributes to load sharing at the osteotomy.

  3. Tibial hyperostosis: A diagnostic approach

    International Nuclear Information System (INIS)

    Touraine, Sébastien; Parlier-Cuau, Caroline; Bousson, Valérie; Sverzut, Jean-Michel; Genah, Idan

    2013-01-01

    Tibial hyperostosis may be encountered in musculoskeletal imaging, incidentally or during the investigation of a leg pain. Hyperostosis involves the exuberant production of osseous tissue and results in cortical, periosteal and/or endosteal thickening of the bone. As a long bone with thick cortices, the tibia has a significant probability of being affected by ubiquitous bone diseases. As a tubular long bone, the tibia is likely to be involved in extensive infectious conditions such as osteomyelitis. As a bone of the lower limb, the tibia undergoes high stresses and may be affected by decrease in bone strength or repetitive submaximal stress. The tibia is also particularly involved in some bone sclerosing dysplasias and Paget's disease. In this work, we aim at highlighting the main conditions leading to tibial hyperostosis and try to provide key elements to narrow down the several diagnostic possibilities. Osteoid osteomas, fatigue or insufficiency fractures, infectious conditions, vascular lesions, sclerosing bone dysplasias and Paget's disease represent the main challenging diagnoses to discuss

  4. Tibial hyperostosis: A diagnostic approach

    Energy Technology Data Exchange (ETDEWEB)

    Touraine, Sébastien, E-mail: sebastien.touraine@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Parlier-Cuau, Caroline, E-mail: caroline.parlier@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Bousson, Valérie, E-mail: valerie.bousson@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Sverzut, Jean-Michel, E-mail: jmsverzut21@hotmail.com [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); Centre d’imagerie du centre cardiologique du Nord, 32-36 rue des Moulins Gémeaux, 93200 Saint-Denis (France); Genah, Idan, E-mail: idan.genah@lrb.aphp.fr [Radiologie ostéo-articulaire, Hôpital Lariboisière, 2 rue Ambroise Paré, 75475 Paris Cedex 10 (France); and others

    2013-12-01

    Tibial hyperostosis may be encountered in musculoskeletal imaging, incidentally or during the investigation of a leg pain. Hyperostosis involves the exuberant production of osseous tissue and results in cortical, periosteal and/or endosteal thickening of the bone. As a long bone with thick cortices, the tibia has a significant probability of being affected by ubiquitous bone diseases. As a tubular long bone, the tibia is likely to be involved in extensive infectious conditions such as osteomyelitis. As a bone of the lower limb, the tibia undergoes high stresses and may be affected by decrease in bone strength or repetitive submaximal stress. The tibia is also particularly involved in some bone sclerosing dysplasias and Paget's disease. In this work, we aim at highlighting the main conditions leading to tibial hyperostosis and try to provide key elements to narrow down the several diagnostic possibilities. Osteoid osteomas, fatigue or insufficiency fractures, infectious conditions, vascular lesions, sclerosing bone dysplasias and Paget's disease represent the main challenging diagnoses to discuss.

  5. In Situ Field Sequencing and Life Detection in Remote (79°26′N Canadian High Arctic Permafrost Ice Wedge Microbial Communities

    Directory of Open Access Journals (Sweden)

    J. Goordial

    2017-12-01

    Full Text Available Significant progress is being made in the development of the next generation of low cost life detection instrumentation with much smaller size, mass and energy requirements. Here, we describe in situ life detection and sequencing in the field in soils over laying ice wedges in polygonal permafrost terrain on Axel Heiberg Island, located in the Canadian high Arctic (79°26′N, an analog to the polygonal permafrost terrain observed on Mars. The life detection methods used here include (1 the cryo-iPlate for culturing microorganisms using diffusion of in situ nutrients into semi-solid media (2 a Microbial Activity Microassay (MAM plate (BIOLOG Ecoplate for detecting viable extant microorganisms through a colourimetric assay, and (3 the Oxford Nanopore MinION for nucleic acid detection and sequencing of environmental samples and the products of MAM plate and cryo-iPlate. We obtained 39 microbial isolates using the cryo-iPlate, which included several putatively novel strains based on the 16S rRNA gene, including a Pedobacter sp. (96% closest similarity in GenBank which we partially genome sequenced using the MinION. The MAM plate successfully identified an active community capable of L-serine metabolism, which was used for metagenomic sequencing with the MinION to identify the active and enriched community. A metagenome on environmental ice wedge soil samples was completed, with base calling and uplink/downlink carried out via satellite internet. Validation of MinION sequencing using the Illumina MiSeq platform was consistent with the results obtained with the MinION. The instrumentation and technology utilized here is pre-existing, low cost, low mass, low volume, and offers the prospect of equipping micro-rovers and micro-penetrators with aggressive astrobiological capabilities. Since potentially habitable astrobiology targets have been identified (RSLs on Mars, near subsurface water ice on Mars, the plumes and oceans of Europa and Enceladus

  6. Group based prenatal care in a low-and high risk population in the Netherlands: a study protocol for a stepped wedge cluster randomized controlled trial.

    Science.gov (United States)

    van Zwicht, Birgit S; Crone, Matty R; van Lith, Jan M M; Rijnders, Marlies E B

    2016-11-15

    CenteringPregnancy (CP) is a multifaceted group based care-model integrated in routine prenatal care, combining health assessment, education, and support. CP has shown some positive results on perinatal outcomes. However, the effects are less obvious when limited to the results of randomized controlled trials: as there are few trials and there is a variation in reported outcomes. Furthermore, former research was mostly conducted in the United States of America and in specific (often high risk) populations. Our study aims to evaluate the effects of CP in the Netherlands in a general population of pregnant women (low and high risk). Furthermore we aim to explore the mechanisms leading to the eventual effects by measuring potential mediating factors. We will perform a stepped wedge cluster randomized controlled trial, in a Western region in the Netherlands. Inclusion criteria are care, women in the intervention period (starting at the randomized time-point) will be offered the choice between individual care or CP. Primary outcomes are maternal and neonatal morbidity, retrieved from a national routine database. Secondary outcomes are health behavior, psychosocial outcomes, satisfaction, health care utilization and process outcomes, collected through self-administered questionnaires, group-evaluations and individual interviews. We will conduct intention-to-treat analyses. Also a per protocol analysis will be performed comparing the three subgroups: control group, CP-participants and non-CP-participants, using multilevel techniques to account for clustering effects. This study contributes to the evidence regarding the effect of CP and gives a first indication of the effect and implementation of CP in both low and high-risk pregnancies in a high-income Western society other than the USA. Also, measuring factors that are hypothesized to mediate the effect of CP will enable to explain the mechanisms that lead to effects on maternal and neonatal outcomes. Dutch Trial

  7. Are Pericentric Inversions Reorganizing Wedge Shell Genomes?

    Directory of Open Access Journals (Sweden)

    Daniel García-Souto

    2017-12-01

    Full Text Available Wedge shells belonging to the Donacidae family are the dominant bivalves in exposed beaches in almost all areas of the world. Typically, two or more sympatric species of wedge shells differentially occupy intertidal, sublittoral, and offshore coastal waters in any given locality. A molecular cytogenetic analysis of two sympatric and closely related wedge shell species, Donax trunculus and Donax vittatus, was performed. Results showed that the karyotypes of these two species were both strikingly different and closely alike; whilst metacentric and submetacentric chromosome pairs were the main components of the karyotype of D. trunculus, 10–11 of the 19 chromosome pairs were telocentric in D. vittatus, most likely as a result of different pericentric inversions. GC-rich heterochromatic bands were present in both species. Furthermore, they showed coincidental 45S ribosomal RNA (rRNA, 5S rRNA and H3 histone gene clusters at conserved chromosomal locations, although D. trunculus had an additional 45S rDNA cluster. Intraspecific pericentric inversions were also detected in both D. trunculus and D. vittatus. The close genetic similarity of these two species together with the high degree of conservation of the 45S rRNA, 5S rRNA and H3 histone gene clusters, and GC-rich heterochromatic bands indicate that pericentric inversions contribute to the karyotype divergence in wedge shells.

  8. The Tax Wedge in Slovenia: International Comparison and Policy Recommendations

    Directory of Open Access Journals (Sweden)

    Primož Dolenc

    2005-09-01

    Full Text Available When taxes on labor are introduced, a “tax wedge” appears between the labor costs paid by the employer (gross wage and the net wage received by an employee. At a certain level of wage, a higher tax wedge increases unemployment and decreases employment, all other things being equal. The paper tackles three main questions: the characteristics of the tax wedge, unemployment and employment rates in OECD countries in the recent past, tax wedge policy in the EU15 and the new EU members and the tax system and its effects on the unemployment and employment rates in Slovenia. We found that the OECD countries can be classified into two groups of countries if the tax wedge, the unemployment rate and the employment rate are taken into consideration. The first group is the high tax wedge, high unemployment rate and low employment rate group of countries, whereas the other group has the opposite characteristics. European member states (old and new have on average a higher tax burden on labor than the OECD average, consequently suffering from higher unemployment rates. Slovenia has an unreasonably high tax wedge; in the EU only Belgium and Germany have a higher tax burden. According to previous and our empirical findings we suggest that Slovenia could benefit from a reduction in the tax wedge.

  9. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  10. BWR reactor water cleanup system flexible wedge gate isolation valve qualification and high energy flow interruption test

    International Nuclear Information System (INIS)

    DeWall, K.G.; Steele, R. Jr.

    1989-10-01

    This report presents the results of research performed to develop technical insights for the NRC effort regarding Generic Issue 87, ''Failure of HPCI Steam Line Without Isolation.'' Volume III of this report contains the data and findings from the original research performed to assess the qualification of the valves and reported in EGG-SSRE-7387, ''Qualification of Valve Assemblies in High Energy BWR Systems Penetrating Containment.'' We present the original work here to complete the documentation trail. The recommendations contained in Volume III of this report resulted in the test program described in Volume I and II. The research began with a survey to characterize the population of normally open containment isolation valves in those process lines that connect to the primary system and penetrate containment. The qualification methodology used by the various manufacturers identified in the survey is reviewed and deficiencies in that methodology are identified. Recommendations for expanding the qualification of valve assemblies for high energy pipe break conditions are presented. 11 refs., 1 fig., 2 tabs

  11. Complications of Open Tibial Fracture Management: Risk Factors and Treatment

    OpenAIRE

    Lua, JYC; Tan, VH; Sivasubramanian, H; Kwek, EBK

    2017-01-01

    Open tibial fractures result in high rates of complications. This study aims to elucidate the risk factors causing these complications, and suggest antimicrobial regimens based on the organisms grown in post-operative infections. Over a period of five years, 173 patients had sustained open tibial fractures and undergone operative treatment at a single institution. All surgical data was gathered retrospectively through online medical records. Thirty-one patients (17.9%) had sustained post-oper...

  12. Employment and productivity: The role of the tax wedge

    Directory of Open Access Journals (Sweden)

    Andrea FESTA

    2015-11-01

    Full Text Available After the economic crisis, many countries aim at reducing unemployment and foster productivity. To address these issues one of the most common policy indications recommends lowering the tax wedge on labour in order to increase employment and growth. As a consequence, a review of the empirical studies focused on the relation between tax wedge, employment and productivity is an useful and demanding exercise, especially in those European countries where the topic is on the front page of the domestic policy debate because the productivity growth is low and the tax wedge on labour is high.

  13. OPTIMAL SURGICAL MANAGEMENT OF HIGH VELOCITY POSTERIOR TIBIAL PLATEAU FRACTURE SUBLUXATIONS (DUPARC, REVISED CLASSIFICATION, GROUP – V: POSTERO - MEDIAL FRACTURE BY DIRECT, DORSAL APPROACH – A CHANGING TREND: A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Pardhasaradhi

    2015-10-01

    Full Text Available INTRODUCTION : High - energy tibial plateau fractures are infrequent and technically demanding to treat especially if those are shearing type, coronal plane, displaced fractures. The most widely used the Schatzker system of classification , [1] ( B ased on the AP radiograph is more than likely to miss postero - medial and postero - lateral shear fractures, best visible on the lateral, than the AP radiograph. These fractures have recently been characterised by two studies, highlighti ng their clinical relevance [ 2,3] and showing that less invasive surgery and indirect reduction techniques are often inadequate. Hohl described unicondylar c oronal plane splitting fractures of the medial tibial plateau, noted that these injuries be considered as fracture - dislocations. Connolly and others have suggested that the mechanism involved in this fracture pattern is one of knee flexion, varus, and inter nal rotation of the medial femoral condyle . [4,5,6 ] Consistent among these and other authors is that the occurrence of this fragment is relatively unusual and that the use of a posteriorly based exposure with direct fracture visualization, anatomic reductio n and absolute stability appears to result in satisfactory outcomes. Though variations of a postero - medial approach been previously described ( by Trickey et al and also by Burks et al.,, more recently, Lobenhoffer et al described direct posterior exposure , Wang et al described postero - medial approach and Luo et al. described the approach for the management of posterior bicondylar tibial plateau fractures . [7,8] These approaches have been used in isolation or as a dual - incision approach for treating tibial plateau fractures . [9,10,11,12,13,14, 15] PURPOSE : The purpose of this study is to describe this unfamiliar direct posterior surgical (Medial Gastrocnemius approach to a general orthopod, highlighting the relevant anatomy and presenting our experience using this approach in treating a

  14. Scattering of wedges and cones with impedance boundary conditions

    CERN Document Server

    Lyalinov, Mikhail

    2012-01-01

    This book is a systematic and detailed exposition of different analytical techniques used in studying two of the canonical problems, the wave scattering by wedges or cones with impedance boundary conditions. It is the first reference on novel, highly efficient analytical-numerical approaches for wave diffraction by impedance wedges or cones. The applicability of the reported solution procedures and formulae to existing software packages designed for real-world high-frequency problems encountered in antenna, wave propagation, and radar cross section.

  15. Chevron closing base wedge bunionectomy.

    Science.gov (United States)

    Bruyn, J M

    1993-01-01

    The Chevron-base wedge Association for Osteosynthesis fixated bunionectomy provides a stable, aggressive correction of the severe hallux abducto valgus deformity. It is intended for the bunion requiring a double osteotomy in order to adequately reduce both intermetatarsal and proximal articular facet angle with minimal shortening and elevation. This article presents the rationale for the procedure, technique, and a 4-year follow-up of six patients with eight Chevron-base wedge bunionectomies.

  16. Effect of Mantle Wedge Hybridization by Sediment Melt on Geochemistry of Arc Magma and Arc Mantle Source - Insights from Laboratory Experiments at High Pressures and Temperatures

    Science.gov (United States)

    Mallik, A.; Dasgupta, R.; Tsuno, K.; Nelson, J. M.

    2015-12-01

    Generation of arc magmas involves metasomatism of the mantle wedge by slab-derived H2O-rich fluids and/or melts and subsequent melting of the modified source. The chemistry of arc magmas and the residual mantle wedge are not only regulated by the chemistry of the slab input, but also by the phase relations of metasomatism or hybridization process in the wedge. The sediment-derived silica-rich fluids and hydrous partial melts create orthopyroxene-rich zones in the mantle wedge, due to reaction of mantle olivine with silica in the fluid/melt [1,2]. Geochemical evidence for such a reaction comes from pyroxenitic lithologies coexisting with peridotite in supra-subduction zones. In this study, we have simulated the partial melting of a parcel of mantle wedge modified by bulk addition of sediment-derived melt with variable H2O contents to investigate the major and trace element chemistry of the magmas and the residues formed by this process. Experiments at 2-3 GPa and 1150-1300 °C were conducted on mixtures of 25% sediment-derived melt and 75% lherzolite, with bulk H2O contents varying from 2 to 6 wt.%. Partial reactive crystallization of the rhyolitic slab-derived melt and partial melting of the mixed source produced a range of melt compositions from ultra-K basanites to basaltic andesites, in equilibrium with an orthopyroxene ± phlogopite ± clinopyroxene ± garnet bearing residue, depending on P and bulk H2O content. Model calculations using partition coefficients (from literature) of trace elements between experimental minerals and silicate melt suggest that the geochemical signatures of the slab-derived melt, such as low Ce/Pb and depletion in Nb and Ta (characteristic slab signatures) are not erased from the resulting melt owing to reactive crystallization. The residual mineral assemblage is also found to be similar to the supra-subduction zone lithologies, such as those found in Dabie Shan (China) and Sanbagawa Belt (Japan). In this presentation, we will also

  17. Phase Space Exchange in Thick Wedge Absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-01-01

    The problem of phase space exchange in wedge absorbers with ionization cooling is discussed. The wedge absorber exchanges transverse and longitudinal phase space by introducing a position-dependent energy loss. In this paper we note that the wedges used with ionization cooling are relatively thick, so that single wedges cause relatively large changes in beam phase space. Calculation methods adapted to such “thick wedge” cases are presented, and beam phase-space transformations through such wedges are discussed.

  18. Measurement of Posterior Tibial Slope Using Magnetic Resonance Imaging.

    Science.gov (United States)

    Karimi, Elham; Norouzian, Mohsen; Birjandinejad, Ali; Zandi, Reza; Makhmalbaf, Hadi

    2017-11-01

    Posterior tibial slope (PTS) is an important factor in the knee joint biomechanics and one of the bone features, which affects knee joint stability. Posterior tibial slope has impact on flexion gap, knee joint stability and posterior femoral rollback that are related to wide range of knee motion. During high tibial osteotomy and total knee arthroplasty (TKA) surgery, proper retaining the mechanical and anatomical axis is important. The aim of this study was to evaluate the value of posterior tibial slope in medial and lateral compartments of tibial plateau and to assess the relationship among the slope with age, gender and other variables of tibial plateau surface. This descriptive study was conducted on 132 healthy knees (80 males and 52 females) with a mean age of 38.26±11.45 (20-60 years) at Imam Reza hospital in Mashhad, Iran. All patients, selected and enrolled for MRI in this study, were admitted for knee pain with uncertain clinical history. According to initial physical knee examinations the study subjects were reported healthy. The mean posterior tibial slope was 7.78± 2.48 degrees in the medial compartment and 6.85± 2.24 degrees in lateral compartment. No significant correlation was found between age and gender with posterior tibial slope ( P ≥0.05), but there was significant relationship among PTS with mediolateral width, plateau area and medial plateau. Comparison of different studies revealed that the PTS value in our study is different from other communities, which can be associated with genetic and racial factors. The results of our study are useful to PTS reconstruction in surgeries.

  19. Understanding the etiology of the posteromedial tibial stress fracture.

    Science.gov (United States)

    Milgrom, Charles; Burr, David B; Finestone, Aharon S; Voloshin, Arkady

    2015-09-01

    Previous human in vivo tibial strain measurements from surface strain gauges during vigorous activities were found to be below the threshold value of repetitive cyclical loading at 2500 microstrain in tension necessary to reduce the fatigue life of bone, based on ex vivo studies. Therefore it has been hypothesized that an intermediate bone remodeling response might play a role in the development of tibial stress fractures. In young adults tibial stress fractures are usually oblique, suggesting that they are the result of failure under shear strain. Strains were measured using surface mounted unstacked 45° rosette strain gauges on the posterior aspect of the flat medial cortex just below the tibial midshaft, in a 48year old male subject while performing vertical jumps, staircase jumps and running up and down stadium stairs. Shear strains approaching 5000 microstrain were recorded during stair jumping and vertical standing jumps. Shear strains above 1250 microstrain were recorded during runs up and down stadium steps. Based on predictions from ex vivo studies, stair and vertical jumping tibial shear strain in the test subject was high enough to potentially produce tibial stress fracture subsequent to repetitive cyclic loading without necessarily requiring an intermediate remodeling response to microdamage. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. [Magnetic resonance imaging of tibial periostitis].

    Science.gov (United States)

    Meyer, X; Boscagli, G; Tavernier, T; Aczel, F; Weber, F; Legros, R; Charlopain, P; Martin, J P

    1998-01-01

    Tibial periostitis frequently occurs in athletes. We present our experience with MRI in a series of 7 patients (11 legs) with this condition. The clinical presentation and scintigraphic scanning suggested the diagnosis. MRI exploration of 11 legs demonstrated a high band-like juxta-osseous signal enhancement of SE and IR T2 weighted sequences in 6 cases, a signal enhancement after i.v. contrast administration in 4. Tibial periostitis is a clinical diagnosis and MRI and scintigraphic findings can be used to assure the differential diagnosis in difficult cases with stress fracture. MRI can visualize juxta-osseous edematous and inflammatory reactions and an increased signal would appear to be characteristic when the band-like image is fixed to the periosteum.

  1. Tibial condylar valgus osteotomy (TCVO) for osteoarthritis of the knee: 5-year clinical and radiological results.

    Science.gov (United States)

    Chiba, Ko; Yonekura, Akihiko; Miyamoto, Takashi; Osaki, Makoto; Chiba, Goji

    2017-03-01

    Tibial condylar valgus osteotomy (TCVO) is a type of opening-wedge high tibial osteotomy for advanced medial knee osteoarthritis (OA) with subluxated lateral joint. We report the concept, the current surgical technique with a locking plate, and the short-term clinical and radiological results of this procedure. 11 knees with medial OA and a widened lateral joint were treated by TCVO (KL stage III: 6, IV: 5). In this procedure, by the L-shaped osteotomy from the medial side of the proximal tibia to the intercondylar eminence and the valgus correction, lateralization of the mechanical axis and reduction of the subluxated lateral joint are obtained with early postoperative weight-bearing. Before, 6 months, 1, and 5 years after the operation, a visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), alignment of the lower extremity, and congruency and stability of the femorotibial joint were investigated. The VAS improved from an average of 73 mm to 13 mm, and the total WOMAC score from 52 to 14 before to 5 years after the operation, respectively. The mechanical axis changed from 1 to 60%, and the FTA changed from 186° to 171°. The joint line convergence angle (JLCA) changed from 6° to 1°, and the angle difference of JLCA between varus and valgus stress improved from 8° to 4° after the procedure. Improvements in pain and activities of daily living were observed by TCVO along with valgus correction of the lower extremity and stabilization of the femorotibial joint.

  2. Fine scale monitoring of ice ablation following convective heat transfer: case study based on ice-wedge thermo-erosion on Bylot Island (Canadian High Arctic) and laboratory observations

    Science.gov (United States)

    Godin, E.; Fortier, D.

    2011-12-01

    the excavated channel just before the water got in contact with the ice surface. The field experiment where flowing water at Tw = 277 K, Ti = 273 K with a water discharge of 0.01 m3 s-1 resulted in a measured Ar of 0.01 to 0.02 m min-1. Water discharge and temperature difference between water and the melting ice were fundamental to ice ablation rate. The recent climate warming in the Canadian High Arctic will likely strongly contribute to the interaction and importance of the thermo-erosion and gullying processes in the High Arctic. Combined factors such as earlier or faster snowmelt, precipitation changes during the summer and positive feedback effects will probably increase the hydrological input to gullies and therefore enhance their development by thermo-erosion. Costard F. et al. 2003. Fluvial thermal erosion investigations along a rapidly eroding river bank: Application to the Lena River (central Siberia). Earth Surface Processes and Landforms 28: 1349-1359. Fortier D. et al. 2007. Observation of rapid drainage system development by thermal erosion of ice wedges on Bylot island, Canadian Arctic Archipelago. Permafrost and Periglacial Processes 18: 229-243.

  3. Field size dependence of wedge factor: miniphantom vs full phantom measurements

    International Nuclear Information System (INIS)

    Allen Li, X.; Szanto, J.; Soubra, M.; Gerig, L. H.

    1995-01-01

    It is empirically known that the transmission factor for wedge in a high-energy photon beam is dependent upon field size and depth of measurement. The field-size dependence of wedge factors may be attributed to changes in (i) head scatter, (ii) phantom scatter, and (iii) backscatter from the wedge into the linac monitor chamber. In this work we present the results of studies designed to examine each of these factors in isolation. The wedge factors for wedges with nominal wedge angles of 15 deg. , 30 deg. , 45 deg. and 60 deg. were measured with a 3-g/cm 2 -diameter narrow cylindrical phantom (miniphantom), a brass cap with 1.5-g/cm 2 side-wall thickness and a full water phantom for 6-, 10- and 18-MV photon beams. The measurements were performed with and without flattening filter in place. The wedge factors measured with the miniphantom and the brass cap exclude the phantom scatter contribution. It has been found that the field-size behaviour of wedge factor measured with full water phantom is similar to that measured with the miniphantom and cap. This indicates that the head scatter radiation is the major contributor to the field size dependence of wedge factors. Wedge factors measured with water phantom are up to 5.0% smaller than those measured with miniphantom. This difference increases with wedge angle. When Measured with the flattening filter removed, the field size dependence of the wedge factor is reduced. This justify that the flattening filter is one of the major contributors to head scatters. The measurement results made with the brass cap agree well with those made by using the miniphantom. By measuring the monitor chamber output, it is found that the backscatters from the wedge into the linac ion chamber have little effect on the field size dependence of the wedge factor

  4. TIBIAL SHAFT FRACTURES.

    Science.gov (United States)

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2011-01-01

    The long-bone fractures occur most frequently in the tibial shaft. Adequate treatment of such fractures avoids consolidation failure, skewed consolidation and reoperation. To classify these fractures, the AO/OTA classification method is still used, but it is worthwhile getting to know the Ellis classification method, which also includes assessment of soft-tissue injuries. There is often an association with compartmental syndrome, and early diagnosis can be achieved through evaluating clinical parameters and constant clinical monitoring. Once the diagnosis has been made, fasciotomy should be performed. It is always difficult to assess consolidation, but the RUST method may help in this. Radiography is assessed in two projections, and points are scored for the presence of the fracture line and a visible bone callus. Today, the dogma of six hours for cleaning the exposed fracture is under discussion. It is considered that an early start to intravenous antibiotic therapy and the lesion severity are very important. The question of early or late closure of the lesion in an exposed fracture has gone through several phases: sometimes early closure has been indicated and sometimes late closure. Currently, whenever possible, early closure of the lesion is recommended, since this diminishes the risk of infection. Milling of the canal when the intramedullary nail is introduced is still a controversial subject. Despite strong personal positions in favor of milling, studies have shown that there may be some advantage in relation to closed fractures, but not in exposed fractures.

  5. Medial tibial stress syndrome.

    Science.gov (United States)

    Reshef, Noam; Guelich, David R

    2012-04-01

    MTSS is a benign, though painful, condition, and a common problem in the running athlete. It is prevalent among military personnel, runners, and dancers, showing an incidence of 4% to 35%. Common names for this problem include shin splints, soleus syndrome, tibial stress syndrome, and periostitis. The exact cause of this condition is unknown. Previous theories included an inflammatory response of the periosteum or periosteal traction reaction. More recent evidence suggests a painful stress reaction of bone. The most proven risk factors are hyperpronation of the foot, female sex, and history of previous MTSS. Patient evaluation is based on meticulous history taking and physical examination. Even though the diagnosis remains clinical, imaging studies, such as plain radiographs and bone scans are usually sufficient, although MRI is useful in borderline cases to rule out more significant pathology. Conservative treatment is almost always successful and includes several options; though none has proven more superior to rest. Prevention programs do not seem to influence the rate of MTSS, though shock-absorbing insoles have reduced MTSS rates in military personnel, and ESWT has shortened the duration of symptoms. Surgery is rarely indicated but has shown some promising results in patients who have not responded to all conservative options.

  6. Coherent beam combination using self-phase locked stimulated Brillouin scattering phase conjugate mirrors with a rotating wedge for high power laser generation.

    Science.gov (United States)

    Park, Sangwoo; Cha, Seongwoo; Oh, Jungsuk; Lee, Hwihyeong; Ahn, Heekyung; Churn, Kil Sung; Kong, Hong Jin

    2016-04-18

    The self-phase locking of a stimulated Brillouin scattering-phase conjugate mirror (SBS-PCM) allows a simple and scalable coherent beam combination of existing lasers. We propose a simple optical system composed of a rotating wedge and a concave mirror to overcome the power limit of the SBS-PCM. Its phase locking ability and the usefulness on the beam-combination laser are demonstrated experimentally. A four-beam combination is demonstrated using this SBS-PCM scheme. The relative phases between the beams were measured to be less than λ/24.7.

  7. Clinical implementation of enhanced dynamic wedge

    International Nuclear Information System (INIS)

    Klein, Eric E.; Zhu Xiaorong; Low, Daniel A.; Drzymala, Robert E.; Harms, William B.; Purdy, James A.

    1996-01-01

    Purpose/Objective: Our clinic has been using dynamic wedge since 1993. We appreciate the customized wedge shaped distributions (independent of field size) and the positive aspects of replacing filters with dynamic jaw motion. Varian recently introduced enhanced dynamic wedge (EDW) software. The EDW can be delivered over; a 30 cm field, asymmetric fields (in both wedged and non-wedged directions), and additional wedge angles (10, 15, 20, 25, 30, 45, 60). The EDW software creates customized segmented treatment tables (STTs) for the desired wedge angle and field size. The STT is created from a 'golden' fluence profile of 60 deg. over 30 cm. The wedge STT is derived using ratio-of-tangents and the truncated field segment extracted from the 'golden' table. A review of our dosimetric studies will be presented as well as a discussion of clinical implementation issues including treatment planning and quality assurance. Methods and Materials: We tested a set of angle and field size combinations chosen to encompass clinical needs. The wedge factor (WF) was measured using an ionization chamber along central axis for symmetric fields ranging from 4 to 20 cm, and asymmetric fields to 30 cm. The non-wedged field dimension was found to be inconsequential. An algorithm was developed to predict the wedge factor for any angle and field dimension. Isodoses were measured with film and used for profile evaluation and treatment planning development. The 'golden' fluence table was used to create a universal 60 deg. 'physical' wedge for planning. The universal wedge is combined with an open field (to derive intermediate wedge angles) and blocked according to the treatment field segment. A quality assurance program was developed that relies on multi-point diode measurements. Results: We found the WF is a function of wedge angle and field settings of the final sweep position. There is a nearly linear dependence of WF vs. field size thus allowing a minimal WF table. This eliminates a

  8. Calibration of the Wedge Prism

    Science.gov (United States)

    Charles B. Briscoe

    1957-01-01

    Since the introduction of plotless cruising in this country by Grosenbaugh and the later suggestion of using a wedge prism as an angle gauge by Bruce this method of determining basal area has been widely adopted in the South. One of the factors contributing to the occasionally unsatisfactory results obtained is failure to calibrate the prism used. As noted by Bruce the...

  9. Primary Ankle Arthrodesis for Severely Comminuted Tibial Pilon Fractures.

    Science.gov (United States)

    Al-Ashhab, Mohamed E

    2017-03-01

    Management of severely comminuted, complete articular tibial pilon fractures (Rüedi and Allgöwer type III) remains a challenge, with few treatment options providing good clinical outcomes. Twenty patients with severely comminuted tibial pilon fractures underwent primary ankle arthrodesis with a retrograde calcaneal nail and autogenous fibular bone graft. The fusion rate was 100% and the varus malunion rate was 10%. Fracture union occurred at a mean of 16 weeks (range, 13-18 weeks) postoperatively. Primary ankle arthrodesis is a successful method for treating highly comminuted tibial pilon fractures, having a low complication rate and a high satisfaction score. [Orthopedics. 2017; 40(2):e378-e381.]. Copyright 2016, SLACK Incorporated.

  10. Analysis of surface and build up region dose for motorized wedge and omni wedge

    International Nuclear Information System (INIS)

    Panta, Raj Kumar; Sundarum, T.

    2008-01-01

    Megavoltage x-ray beam exhibits the well known phenomenon of dose build-up within the first few millimeters of incident phantom surface or skin. The skin sparing effect of high energy gamma or x-ray photon may be reduced or even lost, if the beam is contaminated with electron or low energy photons. Since skin dose in the treatment of deeply seated tumor may be a limiting factor in the delivery of tumoricidal dose due to possible complications such as erythema, desquamation, fibrosis, necrosis and epilation, the dose distribution in the build up region should be known. The objective of this study was to measure and investigate the surface and build-up region dose for 6 MV and 15 MV photon beam for Motorized wedge and Omni wedge in Precise Digital Linear Accelerator (Elekta)

  11. Diffusion induced flow on a wedge-shaped obstacle

    International Nuclear Information System (INIS)

    Zagumennyi, Ia V; Dimitrieva, N F

    2016-01-01

    In this paper the problem of evolution of diffusion induced flow on a wedge-shaped obstacle is analyzed numerically. The governing set of fundamental equations is solved using original solvers from the open source OpenFOAM package on supercomputer facilities. Due to breaking of naturally existing diffusion flux of a stratifying agent by the impermeable surface of the wedge a complex multi-level vortex system of compensatory fluid motions is formed around the obstacle. Sharp edges of the obstacle generate extended high-gradient horizontal interfaces which are clearly observed in laboratory experiments by high-resolution Schlieren visualization. Formation of an intensive pressure depression zone in front of the leading vertex of the wedge is responsible for generation of propulsive force resulting in a self-displacement of the obstacle along the neutral buoyancy horizon in a stably stratified environment. The size of the pressure deficiency area near the sharp vertex of a concave wedge is about twice that for a convex one. This demonstrates a more intensive propulsion mechanism in case of the concave wedge and, accordingly, a higher velocity of its self-movement in a continuously stratified medium. (paper)

  12. Pseudoarthrosis of medial tibial plateau fracture-role of alignment procedure

    Directory of Open Access Journals (Sweden)

    Devgan Ashish

    2013-04-01

    Full Text Available 【Abstract】 Nonunion in tibial plateau fractures is very rare. Limited literature is available on Pubmed search on intraarticular tibial nonunion. Most of the cases reported have been following failed surgical treatment and none was neglected fractures. Three patients of isolated and neglected medial tibial plateau nonunion with almost similar demo-graphic profile are reported in this paper. All the three pa-tients were managed by minimally invasive compression fixation using lag screws supplemented with limb realign-ment procedure of high tibial osteotomy. We discussed the injury mechanism, management and rehabilitation in such cases and reviewed the available literature regarding such a presentation. Key words: Fracture healing; Tibial fractures; Frac-ture fixation; Osteotomy

  13. Medial tibial “spackling” to lessen chronic medial tibial soft tissue irritation

    Directory of Open Access Journals (Sweden)

    J. Ryan Martin, MD

    2016-09-01

    Full Text Available We describe a unique, utilitarian reconstructive treatment option known as tibial “spackling” for chronic, localized medial joint line pain corresponding with progressive radiographic peripheral medial tibial bone loss beneath a well-fixed revision total knee arthroplasty tibial baseplate. It is believed that this localized pain is due to chronic irritation of the medial capsule and collateral ligament from the prominent medial edge of the tibial component. In the setting of failed nonoperative treatment, our experience with utilizing bone cement to reconstruct the medial tibial bone defect and create a smooth medial tibial surface has been successful in eliminating chronic medial soft tissue irritation.

  14. Medial tibial stress syndrome: a critical review.

    Science.gov (United States)

    Moen, Maarten H; Tol, Johannes L; Weir, Adam; Steunebrink, Miriam; De Winter, Theodorus C

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise, with pain on palpation of the tibia over a length of at least 5 cm. Histological studies fail to provide evidence that MTSS is caused by periostitis as a result of traction. It is caused by bony resorption that outpaces bone formation of the tibial cortex. Evidence for this overloaded adaptation of the cortex is found in several studies describing MTSS findings on bone scan, magnetic resonance imaging (MRI), high-resolution computed tomography (CT) scan and dual energy x-ray absorptiometry. The diagnosis is made based on physical examination, although only one study has been conducted on this subject. Additional imaging such as bone, CT and MRI scans has been well studied but is of limited value. The prevalence of abnormal findings in asymptomatic subjects means that results should be interpreted with caution. Excessive pronation of the foot while standing and female sex were found to be intrinsic risk factors in multiple prospective studies. Other intrinsic risk factors found in single prospective studies are higher body mass index, greater internal and external ranges of hip motion, and calf girth. Previous history of MTSS was shown to be an extrinsic risk factor. The treatment of MTSS has been examined in three randomized controlled studies. In these studies rest is equal to any intervention. The use of neoprene or semi-rigid orthotics may help prevent MTSS, as evidenced by two large prospective studies.

  15. Triangular metal wedges for subwavelength plasmon-polariton guiding at telecom wavelengths

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Volkov, V.S.; Nielsen, Rasmus Bundgaard

    2008-01-01

    We report on subwavelength plasmon-polariton guiding by triangular metal wedges at telecom wavelengths. A high-quality fabrication procedure for making gold wedge waveguides, which is also mass- production compatible offering large-scale parallel fabrication of plasmonic components, is developed...

  16. [Operative treatment for complex tibial plateau fractures].

    Science.gov (United States)

    Song, Qi-Zhi; Li, Tao

    2012-03-01

    To explore the surgical methods and clinical evaluation of complex tibial plateau fractures resulted from high-energy injuries. From March 2006 to May 2009,48 cases with complex tibial plateau fractures were treated with open reduction and plate fixation, including 37 males and 11 females, with an average age of 37 years (ranged from 18 to 63 years). According to Schatzker classification, 16 cases were type IV, 20 cases type V and 12 cases type VI. All patients were examined by X-ray flim and CT scan. The function of knee joint were evaluated according to postoperative follow-up X-ray and Knee Merchant Rating. Forty-eight patients were followed up with a mean time of 14 months. According to Knee Merchant Rating, 24 cases got excellent results, 16 cases good, 6 cases fair and 2 cases poor. Appropriate operation time, anatomical reduction, suitable bone graft and reasonable rehabilitation exercises can maximally recovery the function of knee joint.

  17. Comparing virtual with physical wedge for the transmission factors

    International Nuclear Information System (INIS)

    Lin Kuei-Hua; Lin Jao-Perng; Chu Tieh-Chi; Liu Mu-Tai

    2000-01-01

    This paper investigates the discrepancies between virtual wedge and physical wedge at the standard wedge angles of 15, 30, 45, and 60 degrees. The dose distributions for virtual wedge and physics wedge were measured by using a commercial multichamber detector array. The transmission factors of each virtual wedge and physical wedge were measured for Siemens PRIMUS 3008 linear accelerator by single ion chamber. These factors were used to set-up the clinical treatment data tables for clinical dosimetry for virtual wedge utilization. The Wellhoefer IC15, 0.13cc chamber was installed on the chamber frame of Wellhoefer water phantom (48x48x40 cm 3 ). The surface of water was at 100 cm SSD. The output factor in water were measured on the central axis of each field at 5 cm depth for 6MV or 10 cm depth for 15MV X-ray on virtual wedge and physical wedge. Comparing virtual wedge with physical wedge for transmission factor as field size range from 4x4 to 25x25 cm 2 . We have measured the dose distributions using the chamber array for 25x25 cm 2 virtual wedge fields and physical wedge fields at wedge angles of 15deg to 60deg. The dose profiles at various depths were also measured using the chamber array. The transmission factors of each physical wedge were slowly increased as field sizes increase, and had different value for each wedge angle. The transmission factors of each virtual wedge were almost constant value as 1.0 for each wedge angle. The results show that the dose profiles including the penumbra dose measured by the chamber array for virtual wedge agree with those measured for the physical wedge. For transmission factors of virtual wedge were constant value as 1.0 for each angles, namely output without wedge is almost equal to output with wedge on the central axis. Virtual wedge has practical and dosimetric advantages over physical wedge. (author)

  18. MR imaging findings of medial tibial crest friction

    International Nuclear Information System (INIS)

    Klontzas, Michail E.; Akoumianakis, Ioannis D.; Vagios, Ilias; Karantanas, Apostolos H.

    2013-01-01

    Objective: Medial tibial condyle bone marrow edema (BME), associated with soft tissue edema (STe) surrounding the medial collateral ligament, was incidentally observed in MRI examinations of young and athletic individuals. The aim of the present study was to 1. Prospectively investigate the association between these findings and coexistence of localized pain, and 2. Explore the possible contribution of the tibial morphology to its pathogenesis. Methods: The medial tibial condyle crest was evaluated in 632 knee MRI examinations. The angle and depth were measured by two separate evaluators. The presence of STe and BME was recorded. A third evaluator blindly assessed the presence of pain at this site. Results: BME associated with STe was found in 24 patients (with no history of previous trauma, osteoarthritis, tumor or pes anserine bursitis). The mean crest angle was 151.3° (95%CI 147.4–155.3°) compared to 159.4° (95%CI 158.8–160°) in controls (Mann–Whitney test, P < 0.0001). MRI findings were highly predictive of localized pain (sensitivity 92% specificity 99%, Fisher's exact test, P < 0.0001). Conclusion: Friction at the medial tibial condyle crest is a painful syndrome. MRI is a highly specific and sensitive imaging modality for its diagnosis

  19. MR imaging findings of medial tibial crest friction

    Energy Technology Data Exchange (ETDEWEB)

    Klontzas, Michail E., E-mail: miklontzas@gmail.com; Akoumianakis, Ioannis D., E-mail: ioannis.akoumianakis@gmail.com; Vagios, Ilias, E-mail: iliasvagios@gmail.com; Karantanas, Apostolos H., E-mail: akarantanas@gmail.com

    2013-11-01

    Objective: Medial tibial condyle bone marrow edema (BME), associated with soft tissue edema (STe) surrounding the medial collateral ligament, was incidentally observed in MRI examinations of young and athletic individuals. The aim of the present study was to 1. Prospectively investigate the association between these findings and coexistence of localized pain, and 2. Explore the possible contribution of the tibial morphology to its pathogenesis. Methods: The medial tibial condyle crest was evaluated in 632 knee MRI examinations. The angle and depth were measured by two separate evaluators. The presence of STe and BME was recorded. A third evaluator blindly assessed the presence of pain at this site. Results: BME associated with STe was found in 24 patients (with no history of previous trauma, osteoarthritis, tumor or pes anserine bursitis). The mean crest angle was 151.3° (95%CI 147.4–155.3°) compared to 159.4° (95%CI 158.8–160°) in controls (Mann–Whitney test, P < 0.0001). MRI findings were highly predictive of localized pain (sensitivity 92% specificity 99%, Fisher's exact test, P < 0.0001). Conclusion: Friction at the medial tibial condyle crest is a painful syndrome. MRI is a highly specific and sensitive imaging modality for its diagnosis.

  20. Dosimetry and clinical implementation of dynamic wedge

    International Nuclear Information System (INIS)

    Klein, Eric E.; Low, Daniel A.; Meigooni, Ali S.; Purdy, James A.

    1995-01-01

    Purpose: Wedge-shaped isodoses are desired in a number of clinical situations. Physical wedge filters have provided nominal angled isodoses with dosimetric consequences of beam hardening, increased peripheral dosing, nonidealized gradients at deep depths, along with the practical consequences of filter handling and placement problems. Dynamic wedging uses a combination of a moving jaw and changing dose rate to achieve angled isodoses. The clinical implementation of dynamic wedge and an accompanying quality assurance program are discussed in detail. Methods and Materials: The accelerator at our facility has two photon energies (6 MV and 18 MV), currently with dynamic wedge angles of 15 deg. , 30 deg. , 45 deg. , and 60 deg. . The segmented treatment tables (STT) that drive the jaw in concert with a changing dose rate are unique for field sizes ranging from 4.0 cm to 20.0 cm in 05 cm steps, resulting in 256 STTs. Transmission wedge factors were measured for each STT with an ion chamber. Isodose profiles were accumulated with film after dose conversion. For treatment-planning purposes, d max orthogonal dose profiles were measured for open and dynamic fields. Physical filters were assigned empirically via the ratio of open and wedge profiles. Results: A nonlinear relationship with wedge factor and field size was found. The factors were found to be independent of the stationary field setting or second order blocking. Dynamic wedging provided more consistent gradients across the field compared with physical filters. Percent depth doses were found to be closer to open field. The created physical filters provided planned isodoses that closely resembled measured isodoses. Comparative isodose plans show improvement with dynamic wedging. Conclusions: Dynamic weding has practical and dosimetric advantages over physical filters. Table collisions with physical filters are alleviated. Treatment planning has been solved with an empirical solution. Dynamic wedge is a positive

  1. The transverse ligament as a landmark for tibial sagittal insertions of the anterior cruciate ligament: a cadaveric study.

    Science.gov (United States)

    Kongcharoensombat, Wirat; Ochi, Mitsuo; Abouheif, Mohamed; Adachi, Nobuo; Ohkawa, Shingo; Kamei, Goki; Okuhara, Atushi; Shibuya, Hoyatoshi; Niimoto, Takuya; Nakasa, Tomoyuki; Nakamae, Atsuo; Deie, Masataka

    2011-10-01

    The purpose of this study was to determine the relation between the position of the transverse ligament, the anterior edge of the anterior cruciate ligament (ACL) tibial footprint, and the center of the ACL tibial insertion. We used arthroscopy for localization of the anatomic landmarks, followed by insertions of guide pins under direct visualization, and then the position of these guide pins was checked on plain lateral radiographs. The transverse ligament and the anterior aspect of the ACL tibial footprint were identified by arthroscopy in 20 unpaired cadaveric knees (10 left and 10 right). Guide pins were inserted with tibial ACL adapter drill guides under direct observation at the transverse ligament, the anterior aspect of the tibial footprint, and the center of tibial insertion of the ACL. Then, plain lateral radiographs of specimens were taken. The Amis and Jakob line was used to define the attachment of the ACL tibial insertion and the transverse ligament. A sagittal percentage of the location of the insertion point was determined and calculated from the anterior margin of the tibia in the anteroposterior direction. The transverse ligament averaged 21.20% ± 4.1%, the anterior edge of the ACL tibial insertion averaged 21.60% ± 4.0%, and the center of the ACL tibial insertion averaged 40.30% ± 4.8%. There were similar percent variations between the transverse ligament and the anterior edge of the ACL tibial insertion, with no significant difference between them (P = .38). Intraobserver and interobserver reliability was high, with small standard errors of measurement. This study shows that the transverse ligament coincides with the anterior edge of the ACL tibial footprint in the sagittal plane. The transverse ligament can be considered as a new landmark for tibial tunnel positioning during anatomic ACL reconstruction. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  2. Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw

    International Nuclear Information System (INIS)

    Vonk, J E; Mann, P J; Spencer, R G M; Bulygina, E B; Holmes, R M; Dowdy, K L; Davydova, A; Davydov, S P; Zimov, N; Eglinton, T I

    2013-01-01

    Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic permafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by sediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved and highly biologically available (biolabile) upon thaw. A better understanding of the processes regulating Yedoma degradation is important to improve estimates of the response and magnitude of permafrost carbon feedbacks to climate warming. In this study, we examine the composition of ice wedges and the influence of ice wedge thaw on the biolability of Yedoma OM. Incubation assays were used to assess OM biolability, fluorescence spectroscopy to characterize the OM composition, and potential enzyme activity rates to examine the controls and regulation of OM degradation. We show that increasing amounts of ice wedge melt water in Yedoma-leached incubations enhanced the loss of dissolved OM over time. This may be attributed to the presence of low-molecular weight compounds and low initial phenolic content in the OM of ice wedges, providing a readily available substrate that promotes the degradation of Yedoma OC. The physical vulnerability of ice wedges upon thaw (causing irreversible collapse), combined with the composition of ice wedge-engrained OM (co-metabolizing old OM), underlines the particularly strong potential of Yedoma to generate a positive feedback to climate warming relative to other forms of non-ice wedge permafrost. (letter)

  3. Tibial Fractures in Alpine Skiing and Snowboarding in Finland: A Retrospective Study on Fracture Types and Injury Mechanisms in 363 Patients.

    Science.gov (United States)

    Stenroos, A; Pakarinen, H; Jalkanen, J; Mälkiä, T; Handolin, L

    2016-09-01

    Alpine skiing and snowboarding share the hazards of accidents accounting for tibial fractures. The aim of this study was to evaluate the fracture patterns and mechanisms of injury of tibial fractures taking place in downhill skiing and snowboarding. All patients with tibial fracture due to alpine skiing or snowboarding accident treated in four trauma centers next to the largest ski resorts in Finland were analyzed between 2006 and 2012. The hospital records were retrospectively reviewed for data collection: equipment used (skis or snowboard), age, gender, and mechanism of injury. Fractures were classified according to AO-classification. There were 342 skiing and 30 snowboarding related tibial fractures in 363 patients. Tibial shaft fracture was the most common fracture among skiers (n = 215, 63%), followed by proximal tibial fractures (n = 92, 27%). Snowboarders were most likely to suffer from proximal tibial fracture (13, 43%) or tibial shaft fracture (11, 37%). Snowboarders were also more likely than skiers to suffer complex AO type C fractures (23% vs 9%, p jumping (46%). The most important finding was the relatively high number of the tibial plateau fractures among adult skiers. The fracture patterns between snowboarding and skiing were different; the most common fracture type in skiers was spiral tibial shaft fracture compared to proximal tibial fractures in snowboarders. Children had more simple fractures than adults. © The Finnish Surgical Society 2016.

  4. Contact Stress Generation on the UHMWPE Tibial Insert

    Directory of Open Access Journals (Sweden)

    S. Petrović Savić

    2014-12-01

    Full Text Available Total knee replacement (TKR is considered, during last years, as a very successful surgical technique for removing knee joint deformities and eliminating pain caused by cartilage damage. In literature, as primary causes for knee joint endoprothesis damage are cited complex movements which cause occurrences of complex stress conditions, sagital radius conformity, sliding, types of materials etc. Aim of this study is analysis of contact stresses that occur on tibial implant for 15°, 45° and 60° knee flexion and 50 kg, 75 kg, 100 kg and 125 kg weight. Knee joint prosthesis model and finite elements method (FEM analysis are done in software Catia V5. For this analysis we used ultra-high molecular weight polyethylene (UHMWPE for tibial implant material and AISI 316, AISI 317, AISI 321, 17-4PH, CoCrMo, Ti6Al4V and SAE A-286 for femoral component materials. Results show that area of maximal contact stress is identified in medial and lateral part of tibial implant. Von Mises stress values vary regarding of flexion degree and weight, but values are approximate for types of chosen materials. Contact stress location corresponds to damage that occur on tibial implant during exploitation.

  5. Medial tibial stress syndrome: a critical review

    NARCIS (Netherlands)

    Moen, Maarten H.; Tol, Johannes L.; Weir, Adam; Steunebrink, Miriam; de Winter, Theodorus C.

    2009-01-01

    Medial tibial stress syndrome (MTSS) is one of the most common leg injuries in athletes and soldiers. The incidence of MTSS is reported as being between 4% and 35% in military personnel and athletes. The name given to this condition refers to pain on the posteromedial tibial border during exercise,

  6. Incomplete linear tibial fractures in two horses

    International Nuclear Information System (INIS)

    Johnson, P.J.; Allhands, R.V.; Baker, G.J.; Boero, M.J.; Foreman, J.H.; Hyyppa, T.; Huhn, J.C.

    1988-01-01

    Incomplete linear tibial fractures were identified in two horses with the aid of scintigraphy. Both horses were treated successfully by strict stall confinement, and both returned to normal athletic activity. Scintigraphy can be used to facilitate the generally difficult diagnosis of incomplete tibial fractures

  7. Isolating active orogenic wedge deformation in the southern Subandes of Bolivia

    Science.gov (United States)

    Weiss, Jonathan R.; Brooks, Benjamin A.; Foster, James H.; Bevis, Michael; Echalar, Arturo; Caccamise, Dana; Heck, Jacob; Kendrick, Eric; Ahlgren, Kevin; Raleigh, David; Smalley, Robert; Vergani, Gustavo

    2016-08-01

    A new GPS-derived surface velocity field for the central Andean backarc permits an assessment of orogenic wedge deformation across the southern Subandes of Bolivia, where recent studies suggest that great earthquakes (>Mw 8) are possible. We find that the backarc is not isolated from the main plate boundary seismic cycle. Rather, signals from subduction zone earthquakes contaminate the velocity field at distances greater than 800 km from the Chile trench. Two new wedge-crossing velocity profiles, corrected for seasonal and earthquake affects, reveal distinct regions that reflect (1) locking of the main plate boundary across the high Andes, (2) the location of and loading rate at the back of orogenic wedge, and (3) an east flank velocity gradient indicative of décollement locking beneath the Subandes. Modeling of the Subandean portions of the profiles indicates along-strike variations in the décollement locked width (WL) and wedge loading rate; the northern wedge décollement has a WL of ~100 km while accumulating slip at a rate of ~14 mm/yr, whereas the southern wedge has a WL of ~61 km and a slip rate of ~7 mm/yr. When compared to Quaternary estimates of geologic shortening and evidence for Holocene internal wedge deformation, the new GPS-derived wedge loading rates may indicate that the southern wedge is experiencing a phase of thickening via reactivation of preexisting internal structures. In contrast, we suspect that the northern wedge is undergoing an accretion or widening phase primarily via slip on relatively young thrust-front faults.

  8. In vivo biological performance of a novel highly bioactive glass-ceramic (Biosilicate®): A biomechanical and histomorphometric study in rat tibial defects.

    Science.gov (United States)

    Granito, Renata N; Rennó, Ana Claudia; Ravagnani, Christian; Bossini, Paulo S; Mochiuti, Daniel; Jorgetti, Vanda; Driusso, Patricia; Peitl, Oscar; Zanotto, Edgar D; Parizotto, Nivaldo A; Oishi, Jorge

    2011-04-01

    This study aimed to investigate bone responses to a novel bioactive fully crystallized glass-ceramic of the quaternary system P(2)O(5)-Na(2)O-CaO-SiO(2) (Biosilicate®). Although a previous study demonstrated positive effects of Biosilicate® on in vitro bone-like matrix formation, its in vivo effect was not studied yet. Male Wistar rats (n = 40) with tibial defects were used. Four experimental groups were designed to compare this novel biomaterial with a gold standard bioactive material (Bioglass® 45S5), unfilled defects and intact controls. A three-point bending test was performed 20 days after the surgical procedure, as well as the histomorphometric analysis in two regions of interest: cortical bone and medullary canal where the particulate biomaterial was implanted. The biomechanical test revealed a significant increase in the maximum load at failure and stiffness in the Biosilicate® group (vs. control defects), whose values were similar to uninjured bones. There were no differences in the cortical bone parameters in groups with bone defects, but a great deal of woven bone was present surrounding Biosilicate® and Bioglass® 45S5 particulate. Although both bioactive materials supported significant higher bone formation; Biosilicate® was superior to Bioglass® 45S5 in some histomorphometric parameters (bone volume and number of osteoblasts). Regarding bone resorption, Biosilicate® group showed significant higher number of osteoclasts per unit of tissue area than defect and intact controls, despite of the non-significant difference in the osteoclastic surface as percentage of bone surface. This study reveals that the fully crystallized Biosilicate® has good bone-forming and bone-bonding properties. Copyright © 2011 Wiley Periodicals, Inc.

  9. Tibial slope correction combined with second revision ACL produces good knee stability and prevents graft rupture.

    Science.gov (United States)

    Dejour, David; Saffarini, Mo; Demey, Guillaume; Baverel, Laurent

    2015-10-01

    Revision ACL reconstruction requires careful analysis of failure causes particularly in cases of two previous graft ruptures. Intrinsic factors as excessive tibial slope or narrow femoral notch increase failure risks but are rarely addressed in revision surgery. The authors report outcomes, at minimum follow-up of 2 years, for second revision ACL reconstructions combined with tibial deflexion osteotomy for correction of excessive slope (>12°). Nine patients that underwent second revision ACL reconstruction combined with tibial deflexion osteotomy were retrospectively studied. The mean age was 30.3 ± 4.4 years (median 28; range 26-37), and mean follow-up was 4.0 ± 2.0 years (median 3.6; range 2.0-7.6). Autografts were harvested from the quadriceps tendon (n = 8) or hamstrings (n = 1), and tibial osteotomy was done by anterior closing wedge, without detachment of the patellar tendon, to obtain a slope of 3° to 5°. All patients had fused osteotomies, stable knees, and there were no intraoperative or postoperative complications. The mean posterior tibial slope decreased from 13.2° ± 2.6° (median 13°; range 12°-18°) preoperatively to 4.4° ± 2.3° (median 4°; range 2°-8°) postoperatively. The mean Lysholm score was 73.8 ± 5.8 (median 74; range 65-82), and the IKDC-SKF was 71.6 ± 6.1 (median 72.8; range 62.2-78.5). The satisfactory results of second revision ACL reconstruction combined with tibial deflexion osteotomy at minimum follow-up of 2 years suggest that tibia slope correction protects reconstructed ACL from fatigue failure in this study. The authors stress the importance of careful analysis failure causes prior to revision ACL reconstruction, and recommend correction of tibial slope if it exceeds 12°, to reduce the risks of graft retear. III.

  10. Anthropometric measurements of tibial plateau and correlation with the current tibial implants.

    Science.gov (United States)

    Erkocak, Omer Faruk; Kucukdurmaz, Fatih; Sayar, Safak; Erdil, Mehmet Emin; Ceylan, Hasan Huseyin; Tuncay, Ibrahim

    2016-09-01

    The aim of the study was to make an anthropometric analysis at the resected surfaces of the proximal tibia in the Turkish population and to compare the data with the dimensions of tibial components in current use. We hypothesized that tibial components currently available on the market do not fulfil the requirements of this population and a new tibial component design may be required, especially for female patients with small stature. Anthropometric data from the proximal tibia of 226 knees in 226 Turkish subjects were measured using magnetic resonance imaging. We measured the mediolateral, middle anteroposterior, medial and lateral anteroposterior dimensions and the aspect ratio of the resected proximal tibial surface. All morphological data were compared with the dimensions of five contemporary tibial implants, including asymmetric and symmetric design types. The dimensions of the tibial plateau of Turkish knees demonstrated significant differences according to gender (P < 0.05). Among the different tibial implants reviewed, neither asymmetric nor symmetric designs exhibited a perfect conformity to proximal tibial morphology in size and shape. The vast majority of tibial implants involved in this study tend to overhang anteroposteriorly, and a statistically significant number of women (21 %, P < 0.05) had tibial anteroposterior diameters smaller than the smallest available tibial component. Tibial components designed according to anthropometric measurements of Western populations do not perfectly meet the requirements of Turkish population. These data could provide the basis for designing the optimal and smaller tibial component for this population, especially for women, is required for best fit. II.

  11. Outcomes of Surgical Treatment for Anterior Tibial Stress Fractures in Athletes: A Systematic Review.

    Science.gov (United States)

    Chaudhry, Zaira S; Raikin, Steven M; Harwood, Marc I; Bishop, Meghan E; Ciccotti, Michael G; Hammoud, Sommer

    2017-12-01

    Although most anterior tibial stress fractures heal with nonoperative treatment, some may require surgical management. To our knowledge, no systematic review has been conducted regarding surgical treatment strategies for the management of chronic anterior tibial stress fractures from which general conclusions can be drawn regarding optimal treatment in high-performance athletes. This systematic review was conducted to evaluate the surgical outcomes of anterior tibial stress fractures in high-performance athletes. Systematic review; Level of evidence, 4. In February 2017, a systematic review of the PubMed, MEDLINE, Cochrane, SPORTDiscus, and CINAHL databases was performed to identify studies that reported surgical outcomes for anterior tibial stress fractures. Articles meeting the inclusion criteria were screened, and reported outcome measures were documented. A total of 12 studies, published between 1984 and 2015, reporting outcomes for the surgical treatment of anterior tibial stress fractures were included in this review. All studies were retrospective case series. Collectively, surgical outcomes for 115 patients (74 males; 41 females) with 123 fractures were evaluated in this review. The overall mean follow-up was 23.3 months. The most common surgical treatment method reported in the literature was compression plating (n = 52) followed by drilling (n = 33). Symptom resolution was achieved in 108 of 123 surgically treated fractures (87.8%). There were 32 reports of complications, resulting in an overall complication rate of 27.8%. Subsequent tibial fractures were reported in 8 patients (7.0%). Moreover, a total of 17 patients (14.8%) underwent a subsequent procedure after their initial surgery. Following surgical treatment for anterior tibial stress fracture, 94.7% of patients were able to return to sports. The available literature indicates that surgical treatment of anterior tibial stress fractures is associated with a high rate of symptom resolution and return

  12. Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Yohei Tanikake

    2016-12-01

    Full Text Available A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.

  13. Two brittle ductile transitions in subduction wedges, as revealed by topography

    Science.gov (United States)

    Thissen, C.; Brandon, M. T.

    2013-12-01

    Subduction wedges contain two brittle ductile transitions. One transition occurs within the wedge interior, and a second transition occurs along the decollement. The decollement typically has faster strain rates, which suggests that the brittle ductile transition along the decollement will be more rearward (deeper) than the transition within the interior. However, the presence of distinct rheologies or other factors such as pore fluid pressure along the decollement may reverse the order of the brittle-ductile transitions. We adopt a solution by Williams et al., (1994) to invert for these brittle ductile transitions using the wedge surface topography. At present, this model does not include an s point or sediment loading atop the wedge. The Hellenic wedge, however, as exposed in Crete presents an ideal setting to test these ideas. We find that the broad high of the Mediterranean ridge represents the coulomb frictional part of the Hellenic wedge. The rollover in topography north of the ridge results from curvature of the down going plate, creating a negative alpha depression in the vicinity of the Strabo, Pliny, and Ionian 'troughs' south of Crete. A steep topographic rise out of these troughs and subsequent flattening reflects the brittle ductile transition at depth in both the decollement and the wedge interior. Crete exposes the high-pressure viscous core of the wedge, and pressure solution textures provide additional evidence for viscous deformation in the rearward part of the wedge. The location of the decollement brittle ductile transition has been previously poorly constrained, and Crete has never experienced a subduction zone earthquake in recorded history. Williams, C. A., et al., (1994). Effect of the brittle ductile transition on the topography of compressive mountain belts on Earth and Venus. Journal of Geophysical Research Solid Earth

  14. The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: an in vitro study.

    Science.gov (United States)

    Kowaleski, Michael P; Apelt, Detlef; Mattoon, John S; Litsky, Alan S

    2005-01-01

    To compare centered versus distal tibial plateau leveling osteotomy (TPLO) position on cranial tibial subluxation, postoperative tibial plateau angle (TPA), and tibial long axis shift (TLAS). In vitro biomechanical evaluation. Six pairs of canine cadaveric hind limbs. One limb of each pair was randomly assigned to the distal (TPLO-D) or centered (TPLO-C) osteotomy group. Cranial tibial subluxation (CTS) under load was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transection, and after TPLO; a corrected CTS value was also calculated. Postoperative TPA and TLAS were measured. Comparisons were made using 1-way repeated measures ANOVA with a Tukey's multiple comparison post hoc test for CTS, and a Wilcoxon's sign rank test for TPA and TLAS. Significance was set at Pcranial tibial thrust. The centered osteotomy position is geometrically more precise, and biomechanically more effective than the distal position.

  15. Use of Wedge Absorbers in MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Summers, D. [Univ. of Mississippi, Oxford, MS (United States); Mohayai, T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Snopok, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Rogers, C. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL)

    2017-03-01

    Wedge absorbers are needed to obtain longitudinal cooling in ionization cooling. They also can be used to obtain emittance exchanges between longitudinal and transverse phase space. There can be large exchanges in emittance, even with single wedges. In the present note we explore the use of wedge absorbers in the MICE experiment to obtain transverse–longitudinal emittance exchanges within present and future operational conditions. The same wedge can be used to explore “direct” and “reverse” emittance exchange dynamics, where direct indicates a configuration that reduces momentum spread and reverse is a configuration that increases momentum spread. Analytical estimated and ICOOL and G4BeamLine simulations of the exchanges at MICE parameters are presented. Large exchanges can be obtained in both reverse and direct configurations.

  16. Bilateral double level tibial lengthening in dwarfism.

    Science.gov (United States)

    Burghardt, Rolf D; Yoshino, Koichi; Kashiwagi, Naoya; Yoshino, Shigeo; Bhave, Anil; Paley, Dror; Herzenberg, John E

    2015-12-01

    Outcome assessment after double level tibial lengthening in patients with dwarfism. Fourteen patients with dwarfism were analyzed after bilateral simultaneous double level tibial lengthening. Average age was 15.1 years. Average lengthening was 13.5 cm. The two levels were lengthened by an average of 7.5 cm proximally and 6.0 cm distally. Concomitant deformities were also addressed during lengthening. External fixation treatment time averaged 8.8 months. Healing index averaged 0.7 months/cm. Bilateral tibial lengthening for dwarfism is difficult, but the results are usually quite gratifying.

  17. Measurement of tibial torsion by computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jend, H.H.; Heller, M.; Dallek, M.; Schoettle, H. (Hamburg Univ. (Germany, F.R.))

    1981-01-01

    A CT procedure for objective measurements of tibial torsion independent of axial rotation in the nearby joints is described. Transverse sections in defined planes of the tibia permit easy calculation of normal and abnormal congenital or posttraumatic angles of torsion. In 69 limbs normal tibial torsion was 40/sup 0/+-9/sup 0/. In a series of 42 limbs with complicated healing of a fracture of both bones of the leg it is shown that tibial maltorsion is a deformity which in most cases leads to arthrosis of the ankle joint.

  18. Measurement of tibial torsion by computer tomography

    International Nuclear Information System (INIS)

    Jend, H.-H.; Heller, M.; Dallek, M.; Schoettle, H.

    1981-01-01

    A CT procedure for objective measurements of tibial torsion independent of axial rotation in the nearby joints is described. Transverse sections in defined planes of the tibia permit easy calculation of normal and abnormal congenital or posttraumatic angles of torsion. In 69 limbs normal tibial torsion was 40 0 +-9 0 . In a series of 42 limbs with complicated healing of a fracture of both bones of the leg it is shown that tibial maltorsion is a deformity which in most cases leads to arthrosis of the ankle joint. (Auth.)

  19. A Wedge Absorber Experiment at MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermilab; Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [IIT, Chicago; Summers, Don [Mississippi U.

    2017-05-01

    Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

  20. Inclined indentation of smooth wedge in rock mass

    Science.gov (United States)

    Chanyshev, AI; Podyminogin, GM; Lukyashko, OA

    2018-03-01

    The article focuses on the inclined rigid wedge indentation into a rigid-plastic half-plane of rocks with the Mohr–Coulomb-Mohr plasticity. The limiting loads on different sides of the wedge are determined versus the internal friction angle, cohesion and wedge angle. It is shown that when the force is applied along the symmetry axis of the wedge, the zone of plasticity is formed only on one wedge side. In order to form the plasticity zone on both sides of the wedge, it is necessary to apply the force asymmetrically relative to the wedge symmetry axis. An engineering solution for the asymmetrical case implementation is suggested.

  1. Improving tibial component coronal alignment during total knee arthroplasty with use of a tibial planing device.

    Science.gov (United States)

    Patil, Shantanu; D'Lima, Darryl D; Fait, James M; Colwell, Clifford W

    2007-02-01

    The outcomes of knee arthroplasty have been shown to be affected by component alignment. Intramedullary and extramedullary alignment instrumentation are fairly effective for achieving the desired mean tibial component coronal alignment. However, there are outliers representing >3 degrees of varus or valgus alignment with respect to the anatomic tibial shaft axis. We measured the efficacy of a custom tibial planing device for reducing the outliers in tibial alignment. We designed a tibial planing tool in an effort to improve tibial alignment. In one cohort (100 knees), we used traditional intramedullary alignment instrumentation to make the tibial bone cut. In a second cohort (120 knees), we used intramedullary alignment instrumentation to make the cut and also used a custom tool to check the cut and to correct an inexact cut. Tibial tray alignment relative to the long axis of the tibial shaft was measured in the coronal and sagittal planes on postoperative radiographs. The target coronal alignment was 90 degrees with respect to the tibial shaft axis (with alignment). A total of 100 anteroposterior radiographs and sixty-five lateral radiographs were analyzed for the group that was treated with traditional instrumentation alone, and a total of 120 anteroposterior radiographs and fifty-five lateral radiographs were analyzed for the group that was treated with use of the custom tibial planing device. The mean coronal alignment of the tibial component was 89.5 degrees +/- 2.1 degrees in the group that was treated with traditional instrumentation alone and 89.6 degrees +/- 1.4 degrees in the group that was treated with use of the custom planing device. Although the mean coronal alignment was not significantly different, the number of outliers was substantially reduced when the custom planing device was used. All 120 components that had been aligned with use of the custom planing device were within 3 degrees of the target coronal alignment, compared with only eighty

  2. Utilization of an electronic portal imaging device for measurement of dynamic wedge data

    International Nuclear Information System (INIS)

    Elder, Eric S.; Miner, Marc S.; Butker, Elizabeth K.; Sutton, Danny S.; Davis, Lawrence W.

    1996-01-01

    Purpose/Objective: Due to the motion of the collimator during dynamic wedge treatments, the conventional method of collecting comprehensive wedge data with a water tank and a scanning ionization chamber is obsolete. It is the objective of this work to demonstrate the use of an electronic portal imaging device (EPID) and software to accomplish this task. Materials and Methods: A Varian Clinac[reg] 2300 C/D, equipped with a PortalVision TM EPID and Dosimetry Research Mode experimental software, was used to produce the radiation field. The Dosimetry Research Mode experimental software allows for a band of 10 of 256 high voltage electrodes to be continuously read and averaged by the 256 electrometer electrodes. The file that is produced contains data relating to the integrated ionization at each of the 256 points, essentially the cross plane beam profile. Software was developed using Microsoft C ++ to reformat the data for import into a Microsoft Excel spreadsheet allowing for easy mathematical manipulation and graphical display. Beam profiles were measured by the EPID with a 100 cm TSD for various field sizes. Each field size was measured open, steel wedged, and dynamically wedged. Scanning ionization chamber measurements performed in a water tank were compared to the open and steel wedged fields. Ionization chamber measurements taken in a water tank were compared with the dynamically wedged measurements. For the EPID measurements the depth was varied using Gammex RMI Solid Water TM placed directly above the EPID sensitive volume. Bolus material was placed between the Solid Water TM and the EPID to avoid an air gap. Results: Comparison of EPID measurements with those from an ion chamber in a water tank showed a discrepancy of ∼5%. Scans were successfully obtained for open, steel wedged and dynamically wedged beams. Software has been developed to allow for easy graphical display of beam profiles. Conclusions: Measurement of dynamic wedge data proves to be easily

  3. Studying wedge factors and beam profiles for physical and enhanced dynamic wedges

    Directory of Open Access Journals (Sweden)

    Ahmad Misbah

    2010-01-01

    Full Text Available This study was designed to investigate variation in Varian′s Physical and Enhanced Dynamic Wedge Factors (WF as a function of depth and field size. The profiles for physical wedges (PWs and enhanced dynamic wedges (EDWs were also measured using LDA-99 array and compared for confirmation of EDW angles at different depths and field sizes. WF measurements were performed in water phantom using cylindrical 0.66 cc ionization chamber. WF was measured by taking the ratio of wedge and open field ionization data. A normalized wedge factor (NWF was introduced to circumvent large differences between wedge factors for different wedge angles. A strong linear dependence of PW Factor (PWF with depth was observed. Maximum variation of 8.9% and 4.1% was observed for 60° PW with depth at 6 and 15 MV beams respectively. The variation in EDW Factor (EDWF with depth was almost negligible and less than two per cent. The highest variation in PWF as a function of field size was 4.1% and 3.4% for thicker wedge (60° at 6 and 15 MV beams respectively and decreases with decreasing wedge angle. EDWF shows strong field size dependence and significant variation was observed for all wedges at both photon energies. Differences in profiles between PW and EDW were observed on toe and heel sides. These differences were dominant for larger fields, shallow depths, thicker wedges and low energy beam. The study indicated that ignoring depth and field size dependence of WF may result in under/over dose to the patient especially doing manual point dose calculation.

  4. Bypass grafting to the anterior tibial artery.

    Science.gov (United States)

    Armour, R H

    1976-01-01

    Four patients with severe ischaemia of a leg due to atherosclerotic occlusion of the tibial and peroneal arteries had reversed long saphenous vein grafts to the patent lower part of the anterior tibial artery. Two of these grafts continue to function 19 and 24 months after operation respectively. One graft failed on the fifth postoperative day and another occluded 4 months after operation. The literature on femorotibial grafting has been reviewed. The early failure rate of distal grafting is higher than in the case of femoropopliteal bypass, but a number of otherwise doomed limbs can be salvaged. Contrary to widely held views, grafting to the anterior tibial artery appears to give results comparable to those obtained when the lower anastomosis is made to the posterior tibial artery.

  5. Prediction of Tibial Rotation Pathologies Using Particle Swarm Optimization and K-Means Algorithms.

    Science.gov (United States)

    Sari, Murat; Tuna, Can; Akogul, Serkan

    2018-03-28

    The aim of this article is to investigate pathological subjects from a population through different physical factors. To achieve this, particle swarm optimization (PSO) and K-means (KM) clustering algorithms have been combined (PSO-KM). Datasets provided by the literature were divided into three clusters based on age and weight parameters and each one of right tibial external rotation (RTER), right tibial internal rotation (RTIR), left tibial external rotation (LTER), and left tibial internal rotation (LTIR) values were divided into three types as Type 1, Type 2 and Type 3 (Type 2 is non-pathological (normal) and the other two types are pathological (abnormal)), respectively. The rotation values of every subject in any cluster were noted. Then the algorithm was run and the produced values were also considered. The values of the produced algorithm, the PSO-KM, have been compared with the real values. The hybrid PSO-KM algorithm has been very successful on the optimal clustering of the tibial rotation types through the physical criteria. In this investigation, Type 2 (pathological subjects) is of especially high predictability and the PSO-KM algorithm has been very successful as an operation system for clustering and optimizing the tibial motion data assessments. These research findings are expected to be very useful for health providers, such as physiotherapists, orthopedists, and so on, in which this consequence may help clinicians to appropriately designing proper treatment schedules for patients.

  6. Asymmetry in gait pattern following tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

    2017-01-01

    INTRODUCTION: Despite the high number of studies evaluating the outcomes following tibial shaft fractures, the literature lacks studies including objective assessment of patients' recovery regarding gait pattern. The purpose of the present study was to evaluate whether gait patterns at 6 and 12...... months post-operatively following intramedullary nailing of a tibial shaft fracture are different compared with a healthy reference population. PATIENTS AND METHODS: The study design was a prospective cohort study. The primary outcome measurement was the gait patterns at 6 and 12 months post......-operatively measured with a 6-metre-long pressure-sensitive mat. The mat registers footprints and present gait speed, cadence as well as temporal and spatial parameters of the gait cycle. Gait patterns were compared to a healthy reference population. RESULTS: 49 patients were included with a mean age of 43.1 years (18...

  7. Neglected, semimembranosus osteochondral avulsion fracture of the posteromedial tibial plateau

    Directory of Open Access Journals (Sweden)

    Rakesh John

    2018-06-01

    Full Text Available Semimembranosus avulsion fracture is infrequently reported and is easy to miss on plain radiographs; the mechanism of injury is highly controversial. Initial reports linked it to anterior cruciate ligament and medial meniscal tears. We report an osteochondral semimembranosus avulsion fracture of the posteromedial tibial plateau with associated posterior cruciate ligament rupture. Also described is a novel surgical fixation technique for such osteochondral fractures where the surgical exposure is limited due to the obliquity of the fracture line resulting in a greater involvement of the articular cartilage than the small bony component. The fixation technique described may be used for osteochondral fractures where the application of a conventional compression screw may not be feasible. Keywords: Osteochondral fracture, Semimembranosus avulsion fracture, Posteromedial tibial plateau, Neglected, Nonunion

  8. Incidence and epidemiology of tibial shaft fractures.

    Science.gov (United States)

    Larsen, Peter; Elsoe, Rasmus; Hansen, Sandra Hope; Graven-Nielsen, Thomas; Laessoe, Uffe; Rasmussen, Sten

    2015-04-01

    The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Retrospective reviews of clinical and radiological records. A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010. The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have the highest frequency between the age of 30 and 40. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. The majority of tibial shaft fractures occur during walking, indoor activity and sports. The distribution among genders shows that males present a higher frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Mantle wedge serpentinization effects on slab dips

    Directory of Open Access Journals (Sweden)

    Eh Tan

    2017-01-01

    Full Text Available The mechanical coupling between a subducting slab and the overlying mantle wedge is an important factor in controlling the subduction dip angle and the flow in mantel wedge. This paper investigates the role of the amount of mantle serpentinization on the subduction zone evolution. With numerical thermos-mechanical models with elasto-visco-plastic rheology, we vary the thickness and depth extent of mantle serpentinization in the mantle wedge to control the degree of coupling between the slab and mantle wedge. A thin serpentinized mantle layer is required for stable subduction. For models with stable subduction, we find that the slab dip is affected by the down-dip extent and the mantle serpentinization thickness. A critical down-dip extent exists in mantle serpentinization, determined by the thickness of the overriding lithosphere. If the down-dip extent does not exceed the critical depth, the slab is partially coupled to the overriding lithosphere and has a constant dip angle regardless of the mantle serpentinization thickness. However, if the down-dip extent exceeds the critical depth, the slab and the base of the overriding lithosphere would be separated and decoupled by a thick layer of serpentinized peridotite. This allows further slab bending and results in steeper slab dip. Increasing mantle serpentinization thickness will also result in larger slab dip. We also find that with weak mantle wedge, there is no material flowing from the asthenosphere into the serpentinized mantle wedge. All of these results indicate that serpentinization is an important ingredient when studying the subduction dynamics in the mantle wedge.

  10. Treatment of segmental tibial fractures with supercutaneous plating.

    Science.gov (United States)

    He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

    2014-08-01

    Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. Copyright 2014, SLACK Incorporated.

  11. Optical dating of relict sand wedges and composite-wedge pseudomorphs in Flanders, Belgium

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Ghysels, Günther; Murray, Andrew S.

    2009-01-01

    We report on quartz Optically Stimulated Luminescence (OSL) dating of the infill of 14 relict sand wedges and composite-wedge pseudomorphs at 5 different sites in Flanders, Belgium. A laboratory dose recovery test indicates that the single-aliquot regenerative-dose (SAR) procedure is suitable for...

  12. Direct FVM Simulation for Sound Propagation in an Ideal Wedge

    Directory of Open Access Journals (Sweden)

    Hongyu Ji

    2016-01-01

    Full Text Available The sound propagation in a wedge-shaped waveguide with perfectly reflecting boundaries is one of the few range-dependent problems with an analytical solution. This provides a benchmark for the theoretical and computational studies on the simulation of ocean acoustic applications. We present a direct finite volume method (FVM simulation for the ideal wedge problem, and both time and frequency domain results are analyzed. We also study the broadband problem with large-scale parallel simulations. The results presented in this paper validate the accuracy of the numerical techniques and show that the direct FVM simulation could be applied to large-scale complex acoustic applications with a high performance computing platform.

  13. Innovative wedge axe in making split firewood

    International Nuclear Information System (INIS)

    Mutikainen, A.

    1998-01-01

    Interteam Oy, a company located in Espoo, has developed a new method for making split firewood. The tools on which the patented System Logmatic are based are wedge axe and cylindrical splitting-carrying frame. The equipment costs about 495 FIM. The block of wood to be split is placed inside the upright carrying frame and split in a series of splitting actions using the innovative wedge axe. The finished split firewood remains in the carrying frame, which (as its name indicates) also serves as the means for carrying the firewood. This innovative wedge-axe method was compared with the conventional splitting of wood using an axe (Fiskars -handy 1400 splitting axe costing about 200 FIM) in a study conducted at TTS-Institute. There were eight test subjects involved in the study. In the case of the wedge-axe method, handling of the blocks to be split and of the finished firewood was a little quicker, but in actual splitting it was a little slower than the conventional axe method. The average productivity of splitting the wood and of the work stages related to it was about 0.4 m 3 per effective hour in both methods. The methods were also equivalent of one another in terms of the load imposed by the work when measured in terms of the heart rate. As regards work safety, the wedge-axe method was superior to the conventional method, but the continuous striking action and jolting transmitted to the arms were unpleasant (orig.)

  14. [Tibial plateau fractures in winter sports. Current treatment options].

    Science.gov (United States)

    Zimmermann, V

    2014-01-01

    Tibial plateau fractures overall and especially in winter sports are rare. However, the incidence in recent years is increasing. In a retrospective study from 2009-2012, we found 52 injuries affiliated with winter sports. Noticeable was the high rate of severe injury patterns. In 20 of the 52 cases, there were complete articular or bicondylar fractures (38 %). In 25 cases (48 %), fragment dislocation corresponding to the Moore classification was observed. The operative algorithm was based on the initial soft tissue damage and the type of fracture. A two or more stage procedure with first line soft tissue management and temporary external fixation stabilization was performed 12 times. The final internal osteosynthesis was based on the morphology of the fracture, i.e., direct exposition and stabilization of relevant fracture patterns. In 24 cases (46 %), there was a need for two (or more) approaches. In the anterior aspect of the tibial head, customary implants were used; posterior pathologies were stabilized with low-dimension implants. Summarizing with regard to the literature, there is a more discriminating view of tibial plateau fractures, regarding all relevant fracture patterns. Thus, different options in operative access and choice of implants can be made.

  15. Evaluation method of lead measurement accuracy of gears using a wedge artefact

    International Nuclear Information System (INIS)

    Komori, Masaharu; Takeoka, Fumi; Kubo, Aizoh; Okamoto, Kazuhiko; Osawa, Sonko; Sato, Osamu; Takatsuji, Toshiyuki

    2009-01-01

    The reduction of the vibration and noise of gears is an important issue in mechanical devices such as vehicles and wind turbines. The characteristics of the vibration and noise of gears are markedly affected by deviations of the tooth flank form of micrometre order; therefore, a strict quality control of the tooth flank form is required. The accuracy of the lead measurement for a gear-measuring instrument is usually evaluated using a master gear or a lead master. However, it is difficult to manufacture masters with high accuracy because the helix is a complicated geometrical form. In this paper, we propose a method of evaluating a gear-measuring instrument using a wedge artefact, which includes a highly precise plane surface. The concept of the wedge artefact is described and a mathematical model of the measuring condition of the wedge artefact is constructed. Theoretical measurement results for the wedge artefact are calculated. The wedge artefact is designed and produced on the basis of the theoretical measurement results. A measurement experiment using the wedge artefact is carried out and its effectiveness is verified

  16. A paired wedge filter system for compensation in dose differences

    International Nuclear Information System (INIS)

    Kobayashi, H.; Sakurai, Y.; Kondo, S.; Abe, S.; Hayakawa, N.; Aoyama, Y.; Obata, Y.; Ishigaki, T.

    1998-01-01

    Objective: In radiotherapy, it is important to conform the high dose volume to the planned target volume. A variable thickness paired wedge filter system was developed to compensate for dose inhomogeneity arising from field width segment variation in conformal irradiation. Materials and methods: The present study used a 6 MV linear accelerator equipped with multileaf collimator leaves and a paired wedge compensating filter system. The dose variation due to field width was measured in each field segment width. The variation in attenuation of the compensators was measured as a function of filter position. As the field width increases, the relative absorbed dose also increases; this is the point of requiring compensation, so it can be in reverse proportion. Results: As the field width increases, the relative absorbed dose also increases; this is why compensation is required and thus it must be in reverse proportion. Attenuation of the absorbed dose by the paired filters was in proportion to the filter position. The filter position to compensate for the difference of absorbed doses was defined by the square root of the field width. For a field varying in width from 4 to 16 cm, the variation in the absorbed dose across the field was reduced from 12% to 2.7%. Conclusion: This paired wedge filter system reduced absorbed dose variations across multileaf collimator shaped fields and can facilitate treatment planning in conformal therapy. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Stacking and metamorphism of continuous segments of subducted lithosphere in a high-pressure wedge: The example of Alpine Corsica (France)

    Science.gov (United States)

    Vitale Brovarone, Alberto; Beyssac, Olivier; Malavieille, Jacques; Molli, Giancarlo; Beltrando, Marco; Compagnoni, Roberto

    2013-01-01

    Alpine Corsica consists of a stack of variably metamorphosed units of continental and Tethys-derived rocks. It represents an excellent example of high-pressure (HP) orogenic belt, such as the Western Alps, exposed over a small and accessible area. Compared to the Western Alps, the geology of Alpine Corsica is poorly unraveled. During the 1970s-80s, based on either lithostratigraphic or metamorphic field observations, various classifications of the belt have been proposed, but these classifications have been rarely matched together. Furthermore, through time, the internal complexity of large domains has been progressively left aside in the frame of large-scale geodynamic reconstructions. As a consequence, major open questions on the internal structure of the belt have remained unsolved. Apart from a few local studies, Alpine Corsica has not benefited of modern developments in petrology and basin research. This feature results in several uncertainties when combining lithostratigraphic and metamorphic patterns and, consequently, in the definition of an exhaustive architecture of the belt. In this paper we provide a review on the geology of Alpine Corsica, paying particular attention to the available lithostratigraphic and metamorphic classifications of the metamorphic terranes. These data are completed by a new and exhaustive metamorphic dataset obtained by means of thermometry based on Raman Spectroscopy of Carbonaceous Material (RSCM). This technique provides reliable insights on the peak temperature of the metamorphic history for CM-bearing metasediments. A detailed metamorphic characterization of metasediments, which have been previously largely ignored due to retrogression or to the lack of diagnostic mineralogy, is thus obtained and fruitfully coupled with the available lithostratigraphic data. Nine main tectono-metamorphic units are defined, from subgreenschist (ca. 280-300 °C) to the lawsonite-eclogite-facies (ca. 500-550 °C) condition. These units are

  18. Convolution-wedge product of fields

    International Nuclear Information System (INIS)

    Diep, D.N.; Duc, D.V.; Tan, H.V.; Viet, N.A.

    2007-07-01

    In this paper we use the pair of electric-magnetic (or GNO, or Langlands) duality groups G = Sp(1) and L G = SO(3) and the T-transformation in mirror symmetry (or the S-duality, or the Fourier-Mukai transformation) to define the wedge product of fields: first by using gauge transformation, we reduce the fields with values in LieG = sp(1) to the fields with values in the Lie algebra of the maximal torus t subset of LieG = sp(1). Next we use the Fourier-Mukai transformation of fields to have the images as fields with values in the Lie algebra of the Langlands dual torus L t in Lie L G = so(3). The desired wedge product of two fields is defined as the pre-image of the ordinary wedge product of images with values in L t subset of so(3). (author)

  19. Surgical quality of wedge resection affects overall survival in patients with early stage non-small cell lung cancer.

    Science.gov (United States)

    Ajmani, Gaurav S; Wang, Chi-Hsiung; Kim, Ki Wan; Howington, John A; Krantz, Seth B

    2018-07-01

    Very few studies have examined the quality of wedge resection in patients with non-small cell lung cancer. Using the National Cancer Database, we evaluated whether the quality of wedge resection affects overall survival in patients with early disease and how these outcomes compare with those of patients who receive stereotactic radiation. We identified 14,328 patients with cT1 to T2, N0, M0 disease treated with wedge resection (n = 10,032) or stereotactic radiation (n = 4296) from 2005 to 2013 and developed a subsample of propensity-matched wedge and radiation patients. Wedge quality was grouped as high (negative margins, >5 nodes), average (negative margins, ≤5 nodes), and poor (positive margins). Overall survival was compared between patients who received wedge resection of different quality and those who received radiation, adjusting for demographic and clinical variables. Among patients who underwent wedge resection, 94.6% had negative margins, 44.3% had 0 nodes examined, 17.1% had >5 examined, and 3.0% were nodally upstaged; 16.7% received a high-quality wedge, which was associated with a lower risk of death compared with average-quality resection (adjusted hazard ratio [aHR], 0.74; 95% confidence interval [CI], 0.67-0.82). Compared with stereotactic radiation, wedge patients with negative margins had significantly reduced hazard of death (>5 nodes: aHR, 0.50; 95% CI, 0.43-0.58; ≤5 nodes: aHR, 0.65; 95% CI, 0.60-0.70). There was no significant survival difference between margin-positive wedge and radiation. Lymph nodes examined and margins obtained are important quality metrics in wedge resection. A high-quality wedge appears to confer a significant survival advantage over lower-quality wedge and stereotactic radiation. A margin-positive wedge appears to offer no benefit compared with radiation. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  20. Irradiation of parametria by double-wedge

    International Nuclear Information System (INIS)

    Weisz, Csaba; Katona, Ernoe; Zarand, Pal; Polgar, Istvan; Nemeth, Gyoergy

    1984-01-01

    The dose distribution of a cobalt unit modified with a double-wedge as well as its combination with intracavitary radiotherapy was investigated. The measurements were made in both Alderson-Rando and wather phantom by using film densitometry, thermoluminescence dosimetry and ionization chambers. The dose distribution calculated on the basis of the Van de Geij program was in good agreement with the measurements. A homogeneous irradiation of the parametria can be obtained by using a combination of intracavitary and external double-wedge irradiation. (author)

  1. Graphene Plasmons in Triangular Wedges and Grooves

    DEFF Research Database (Denmark)

    Gonçalves, P. A. D.; Dias, E. J. C.; Xiao, Sanshui

    2016-01-01

    and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a system, including the complete determination of their spectrum and corresponding induced potential...... and electric-field distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their flat-graphene plasmon counterparts, but now scaled by a (purely) geometric factor in which all the information about the system’s geometry is contained. We...

  2. Anatomic single-bundle ACL surgery: consequences of tibial tunnel diameter and drill-guide angle on tibial footprint coverage.

    Science.gov (United States)

    Van der Bracht, H; Verhelst, L; Stuyts, B; Page, B; Bellemans, J; Verdonk, P

    2014-05-01

    To investigate the consequences of differences in drill-guide angle and tibial tunnel diameter on the amount of tibial anatomical anterior cruciate ligament (ACL) footprint coverage and the risk of overhang of the tibial tunnel aperture over the edges of the native tibial ACL footprint. Twenty fresh-frozen adult human knee specimens with a median age of 46 years were used for this study. Digital templates mimicking the ellipsoid aperture of tibial tunnels with a different drill-guide angle and a different diameter were designed. The centres of these templates were positioned over the geometric centre of the tibial ACL footprint. The amount of tibial ACL footprint coverage and overhang was calculated. Risk factors for overhang were determined. Footprint coverage and the risk of overhang were also compared between a lateral tibial tunnel and a classic antero-medial tibial tunnel. A larger tibial tunnel diameter and a smaller drill-guide angle both will create significant more footprint coverage and overhang. In 45% of the knees, an overhang was created with a 10-mm diameter tibial tunnel with drill-guide angle 45°. Furthermore, a lateral tibial tunnel was found not to be at increased risk of overhang. A larger tibial tunnel diameter and a smaller drill-guide angle both will increase the amount of footprint coverage. Inversely, larger tibial tunnel diameters and smaller drill-guide angles will increase the risk of overhang of the tibial tunnel aperture over the edges of the native tibial ACL footprint. A lateral tibial tunnel does not increase the risk of overhang.

  3. The Effect of Patient-Specific Instrumentation Incorporating an Extramedullary Tibial Guide on Operative Efficiency for Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Oh-Ryong Kwon

    2017-01-01

    Full Text Available This retrospective study was to determine if patient-specific instrumentation (PSI for total knee arthroplasty (TKA leads to shortened surgical time through increased operating room efficiency according to different tibial PSI designs. 166 patients underwent primary TKA and were categorized into three groups as follows: PSI without extramedullary (EM tibial guide (group 1, n=48, PSI with EM tibial guide (group 2, n=68, and conventional instrumentation (CI group (group 3, n=50. Four factors were compared between groups, namely, operative room time, thickness of bone resection, tibial slope, and rotation of the component. The mean surgical time was significantly shorter in the PSI with EM tibial guide group (group 2, 63.9±13.6 min compared to the CI group (group 3, 82.8±24.9 min (P<0.001. However, there was no significant difference in the PSI without EM tibial guide group (group 1, 75.3±18.8 min. This study suggests that PSI incorporating an EM tibial guide may lead to high operative efficiency in TKA compared to CI. This trial is registered with KCT0002384.

  4. A PROSPECTIVE STUDY OF DISTAL TIBIAL FRACTURES BY MIPO (LCP

    Directory of Open Access Journals (Sweden)

    Chandra Sekharam Naidu

    2015-05-01

    Full Text Available INTRODUCTION: D istal tibial fractures represent a significant challenge to most of the surgeons even today. They constitute 1 - 10% of all lower extremity fractures . 1 The difficulty in treating the fractures of distal tibial end is exemplif ied by orthopedists, who in the first half of twentieth century, believed these injuries were so severe and fraught with so many complications, that these fractures were deemed not amenable for surgical reconstruction . 2 Conservative treatment by POP cast l ead to prolonged immobilization, leading to ankle and knee stiffness affecting quality of life of the patient . 3 Operative treatment is indicated for most tibial fractures caused by high energy trauma. Operative treatment allows early motion, and avoids sho rtening and other complications associated with prolonged immobilization . 4 The fundamental goal of treatment of distal tibial fractures is restoration of normal or near normal alignment and articular congruity and finally to obtain a well healed fracture; pain free weight bearing ; and functional ROM of ankle joint. For the past decade, plating has been successful in treating complex fractures of the lower extremity especially distal tibia . 5 Conventional ORIF have been associated with complications like infe ction and delayed or non - union due to devitalisation of bony fragments and additional damage to the soft tissues . 6 To improve fracture healing, more “biological” methods have been developed in the last decade to lessen the surgical dissection, preserving b lood supply to bony fragments and containing at least partially the fracture haematoma . 7 Recently, the trend is towards use of a Locking compression plate for treatment of fractures of the distal part of the tibia 8 . Compared with a conventional plate, a Lo cking compression plate imparts a higher degree of stability and provides better protection against primary and secondary losses of reduction and minimization of bone

  5. Tibial bone fractures occurring after medioproximal tibial bone grafts for oral and maxillofacial reconstruction.

    Science.gov (United States)

    Kim, Il-Kyu; Cho, Hyun-Young; Pae, Sang-Pill; Jung, Bum-Sang; Cho, Hyun-Woo; Seo, Ji-Hoon

    2013-12-01

    Oral and maxillofacial defects often require bone grafts to restore missing tissues. Well-recognized donor sites include the anterior and posterior iliac crest, rib, and intercalvarial diploic bone. The proximal tibia has also been explored as an alternative donor site. The use of the tibia for bone graft has many benefits, such as procedural ease, adequate volume of cancellous and cortical bone, and minimal complications. Although patients rarely complain of pain, swelling, discomfort, or dysfunction, such as gait disturbance, both patients and surgeons should pay close attention to such after effects due to the possibility of tibial fracture. The purpose of this study is to analyze tibial fractures that occurring after osteotomy for a medioproximal tibial graft. An analysis was intended for patients who underwent medioproximal tibial graft between March 2004 and December 2011 in Inha University Hospital. A total of 105 subjects, 30 females and 75 males, ranged in age from 17 to 78 years. We investigated the age, weight, circumstance, and graft timing in relation to tibial fracture. Tibial fractures occurred in four of 105 patients. There were no significant differences in graft region, shape, or scale between the fractured and non-fractured patients. Patients who undergo tibial grafts must be careful of excessive external force after the operation.

  6. [Surgical approaches to tibial plateau fractures].

    Science.gov (United States)

    Krause, Matthias; Müller, Gunnar; Frosch, Karl-Heinz

    2018-06-06

    Intra-articular tibial plateau fractures can present a surgical challenge due to complex injury patterns and compromised soft tissue. The treatment goal is to spare the soft tissue and an anatomical reconstruction of the tibial articular surface. Depending on the course of the fracture, a fracture-specific access strategy is recommended to provide correct positioning of the plate osteosynthesis. While the anterolateral approach is used in the majority of lateral tibial plateau fractures, only one third of the joint surface is visible; however, posterolateral fragments require an individual approach, e. g. posterolateral or posteromedial. If necessary, osteotomy of the femoral epicondyles can improve joint access for reduction control. Injuries to the posterior columns should be anatomically reconstructed and biomechanically correctly addressed via posterior approaches. Bony posterior cruciate ligament tears can be refixed via a minimally invasive posteromedial approach.

  7. Recession wedge trochleoplasty as an additional procedure in the surgical treatment of patellar instability with major trochlear dysplasia: early results.

    Science.gov (United States)

    Thaunat, M; Bessiere, C; Pujol, N; Boisrenoult, P; Beaufils, P

    2011-12-01

    The importance of a dysplastic trochlea as a component of patellar instability has long been recognized. An original trochleoplasty technique consisting in retro-trochlear recession wedge osteotomy was described by Goutallier et al. The aim is not to fashion a groove but to reduce the bump without modifying patellofemoral congruence. This retrospective study reports the operative technique and short-term outcomes of a consecutive case series of 17 patients (19 knees) who underwent recession wedge trochleoplasty for patellofemoral instability associated with severe trochlear dysplasia. Other contributing factors of patellar instability were also corrected as part of the surgical procedure: tibial tuberosity transfer (n=18), MPFL reconstruction (n=8). Minimum follow-up was 12 months (mean, 34 months; range, 12 to 71 months). The trochlear prominence was reduced from a mean 4.8mm (range, 0 to 8mm) to -0.8mm (range, -8 to 6mm). Patellar tilt was reduced from a mean 14° (range, 6° to 26°) to 6° (range, -1° to 24°). Two cases showed recurrent patellofemoral instability. Mean Kujala, KOOS and IKDC score were respectively 80 (± 17), 70 (± 18) and 67 (± 17) at last follow-up. Three patients required further operations, apart from removal of metal screws: arthroscopic arthrolysis for stiffness (n=1), revision for tibial tuberosity non-union (n=1), and supratrochlear exostosectomy (n=1). Recession wedge trochleoplasty is a feasible additional procedure addressing bony trochlear abnormality in the surgical treatment of patellar instability. Our attitude is to perform it never in isolation but associated to realignment of the extensor apparatus according to the à la carte surgery concept. It seems to be effective in preventing future patellar dislocation and reducing anterior knee pain in case of painful patellofemoral instability with a major dysplastic trochlea, or in revision cases when other realignment procedures have failed. Copyright © 2011 Elsevier Masson SAS

  8. Tibial Stress Injuries: Decisive Diagnosis and Treatment of "Shin Splints."

    Science.gov (United States)

    Couture, Christopher J.; Karlson, Kristine A.

    2002-01-01

    Tibial stress injuries, commonly called shin splints, often result when bone remodeling processes adopt inadequately to repetitive stress. Physicians who are caring for athletic patients must have a thorough understanding of this continuum of injuries, including medial tibial stress syndrome and tibial stress fractures, because there are…

  9. Navigating high-risk surgery: protocol for a multisite, stepped wedge, cluster-randomised trial of a question prompt list intervention to empower older adults to ask questions that inform treatment decisions.

    Science.gov (United States)

    Taylor, Lauren J; Rathouz, Paul J; Berlin, Ana; Brasel, Karen J; Mosenthal, Anne C; Finlayson, Emily; Cooper, Zara; Steffens, Nicole M; Jacobson, Nora; Buffington, Anne; Tucholka, Jennifer L; Zhao, Qianqian; Schwarze, Margaret L

    2017-05-29

    Older patients frequently undergo operations that carry high risk for postoperative complications and death. Poor preoperative communication between patients and surgeons can lead to uninformed decisions and result in unexpected outcomes, conflict between surgeons and patients, and treatment inconsistent with patient preferences. This article describes the protocol for a multisite, cluster-randomised trial that uses a stepped wedge design to test a patient-driven question prompt list (QPL) intervention aimed to improve preoperative decision making and inform postoperative expectations. This Patient-Centered Outcomes Research Institute-funded trial will be conducted at five academic medical centres in the USA. Study participants include surgeons who routinely perform vascular or oncological surgery, their patients and families. We aim to enrol 40 surgeons and 480 patients over 24 months. Patients age 65 or older who see a study-enrolled surgeon to discuss a vascular or oncological problem that could be treated with high-risk surgery will be enrolled at their clinic visit. Together with stakeholders, we developed a QPL intervention addressing preoperative communication needs of patients considering major surgery. Guided by the theories of self-determination and relational autonomy, this intervention is designed to increase patient activation. Patients will receive the QPL brochure and a letter from their surgeon encouraging its use. Using audio recordings of the outpatient surgical consultation, patient and family member questionnaires administered at three time points and retrospective chart review, we will compare the effectiveness of the QPL intervention to usual care with respect to the following primary outcomes: patient engagement in decision making, psychological well-being and post-treatment regret for patients and families, and interpersonal and intrapersonal conflict relating to treatment decisions and treatments received. Approvals have been granted by the

  10. Cyclicity, episodicity, and continuity in accretionary wedge evolution: insights from geophysical imaging and physical analogue experiments

    Science.gov (United States)

    Kukowski, N.

    2009-04-01

    Geophysical profiles across active convergent margins reveal different styles and locations of sediment accretion, thrust slices dipping successively steeper towards the hinterland, splay faults, and blind thrusts as well as accumulation spaces e. g. thrust top basins and larger basins formed by regional subsidence, of very variable size and position. Morphologically, the continental slope at most margins can be sub-divided in a lower, middle, and upper slope, with often the middle slope being the most shallowly inclined, suggesting segmented wedges. Beneath the forearc, a subduction channel of a few hundred meters to a few km thickness marks a layer of material transport into greater depth that also hosts the plate interface and décollement zone. The petrographical composition of accretionary wedges and subduction channels as well as related pressures and temperatures are accessible through deep drilling or sampling fossil accretionary complexes now exhumed. The structure, lithology, and tectonic history of forearcs as identified from geophysical and geology field observations hint to parameters possibly controlling material transfer at convergent margins. Among them, sediment supply, which itself is largely controlled by climate, width of the subduction channel, and interplate frictional properties, which also exhibit control on plate coupling and therefore the seismic potential of a forearc, are suggested to be of major importance. These parameters further may undergo temporal fluctuation, e.g. when climate changes or when different material is entering the trench and therefore potentially also the subduction channel. High resolution monitoring of material flux and the evolution of fault zone kinematics of analogue experimental wedges made of granular materials exhibiting frictional behaviour equivalent to that of upper crustal rocks shows that accretionary cycles proceed as a chain of sub-processes, i.e. the development of a thrust slice from initial failure

  11. Quench propagation across the copper wedges in SSC dipoles

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Robins, K.E.; Sampson, W.B.

    1986-01-01

    The effect of copper wedges on quench propagation in SSC windings has been studied. The results indicate that the turn-to-turn quench transit time for conductors separated by an insulated copper wedge can be predicted with reasonable accuracy from the bulk quench properties and the mean wedge thickness

  12. 49 CFR 215.113 - Defective plain bearing wedge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing wedge. 215.113 Section 215... Suspension System § 215.113 Defective plain bearing wedge. A railroad may not place or continue in service a car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  13. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    International Nuclear Information System (INIS)

    Burnstein, M.I.; De Smet, A.A.; Breed, A.L.; Thomas, J.R.; Hafez, G.R.

    1989-01-01

    A patient is described with lower extremity mesomelic dwarfism associated with bilateral congenital elbow, hip, and knee dislocations. Rhomboid-shaped tibiae and delayed ossification of the primary fibular ossification centers were demonstrated at birth. Plain films and magnetic resonance imaging revealed that the tibial deformities were due to the presence of longitudinal epiphyseal brackets. These brackets were observed at surgery and confirmed histologically. Recognition of the longitudinal epiphyseal bracket and its relationship to the tibial deformities seen in this patient with Nievergelt syndrome is important for planning surgical treatment. (orig.)

  14. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Burnstein, M.I.; De Smet, A.A.; Breed, A.L.; Thomas, J.R.; Hafez, G.R.

    1989-04-01

    A patient is described with lower extremity mesomelic dwarfism associated with bilateral congenital elbow, hip, and knee dislocations. Rhomboid-shaped tibiae and delayed ossification of the primary fibular ossification centers were demonstrated at birth. Plain films and magnetic resonance imaging revealed that the tibial deformities were due to the presence of longitudinal epiphyseal brackets. These brackets were observed at surgery and confirmed histologically. Recognition of the longitudinal epiphyseal bracket and its relationship to the tibial deformities seen in this patient with Nievergelt syndrome is important for planning surgical treatment. (orig.).

  15. Tibial and fibular developmental fields defects

    International Nuclear Information System (INIS)

    Khoury, N.J.; Haddad, M.C.; Hourani, M.H.

    1999-01-01

    Malformations of the lower limbs are rare and heterogeneous anomalies. To explain the diversity and complexity of these abnormalities, authors introduced the concept of tibial and fibular developmental fields. Defects in these fields are responsible for different malformations, which have been described, to our knowledge, in only one report in the radiology literature. We present a case of a newborn with femoral bifurcation, absent fibulae and talar bones, ankle and foot malformations, and associated atrial septal defect. Our case is an example of defects in both fibular and tibial developmental fields. (orig.)

  16. Contralateral breast dose reduction using a virtual wedge

    International Nuclear Information System (INIS)

    Yeo, In Hwan; Kim, Dae Yong; Kim, Tae Hyun; Shin, Kyung Hwan; Chie, Eui Kyu; Park, Won; Lim, Do Hoon; Huh, Seung Jae; Ahn, Yong Chan

    2005-01-01

    To evaluate the contralateral breast dose using a virtual wedge compared with that using a physical wedge and an open beam in a Siemens linear accelerator. The contralateral breast dose was measured using diodes placed on a humanoid phantom. Diodes were placed at 5.5 cm (position 1), 9.5 cm (position 2), and 14 cm (position 3) along the medial-lateral line from the medial edge of the treatment field. A 6-MV photon beam was used with tangential irradiation technique at 50 and 230 degrees of gantry angle. Asymmetrically collimated 17 x 10 cm field was used. For the first set of experiment, four treatment set-ups were used, which were an open medial beam with a 30-degree wedged lateral beam (physical and virtual wedges, respectively) and a 15-degree wedge medial beam with a 15-degree wedged lateral beam (physical and virtual wedges, respectively). The second set of experiment consists of setting with medial beam without wedge, a 15-degree wedge, and a 60-degree wedge (physical and virtual wedges, respectively). Identical monitor units were delivered. Each set of experiment was repeated for three times. In the first set of experiment, the contralateral breast dose was the highest at the position 1 and decreased in order of the position 2 and 3. The contralateral breast dose was reduced with open beam on the medial side (2.70± 1.46%) compared to medial beam with a wedge (both physical and virtual) (3.25 ± 1.59%). The differences were larger with a physical wedge (0.99 ± 0.18%) than a virtual wedge (0.10 ± 0.01%) at all positions. The use of a virtual wedge reduced the contralateral breast dose by 0.12% to 1.20% of the prescribed dose compared to a physical wedge with same technique. In the second experiment, the contralateral breast dose decreased in order of the open beam, the virtual wedge, and the physical wedge at the position 1, and it decreased in order of a physical wedge, an open beam, and a virtual wedge at the position 2 and 3. The virtual wedge equipped

  17. Measured Hydrologic Storage Characteristics of Three Major Ice Wedge Polygon Types, Barrow, Alaska

    Science.gov (United States)

    Chamberlain, A. J.; Liljedahl, A.; Wilson, C. J.; Cable, W.; Romanovsky, V. E.

    2014-12-01

    Model simulations have suggested that the hydrologic fluxes and stores of Arctic wetlands are constrained by the micro-topographical features of ice wedge polygons, which are abundant in lowland tundra landscapes. Recently observed changes in ice wedge polygon landscapes - in particular, ice wedge degradation and trough formation - emphasize the need to better understand how differing ice wedge polygon morphologies affect the larger hydrologic system. Here we present three seasons of measured end-of-winter snow accumulation, continuous soil moisture and water table elevations, and repeated frost table mapping. Together, these describe the hydrologic characteristics of three main ice wedge polygon types: low centered polygons with limited trough development (representative of a ~500 year old vegetated drained thaw lake basin), and low- and high-centered polygons with well-defined troughs. Dramatic spatiotemporal variability exists both between polygon types and between the features of an individual polygon (e.g. troughs, centers, rims). Landscape-scale end-of-winter snow water equivalent is similar between polygon types, while the sub-polygon scale distribution of the surface water differs, both as snow and as ponded water. Some sub-polygon features appear buffered against large variations in water levels, while others display periods of prolonged recessions and large responses to rain events. Frost table elevations in general mimic the ground surface topography, but with spatiotemporal variability in thaw rate. The studied thaw seasons represented above long-term average rainfall, and in 2014, record high June precipitation. Differing ice wedge polygon types express dramatically different local hydrology, despite nearly identical climate forcing and landscape-scale snow accumulation, making ice wedge polygons an important component when describing the Arctic water, nutrient and energy system.

  18. Climate adaptation wedges: a case study of premium wine in the western United States

    International Nuclear Information System (INIS)

    Diffenbaugh, Noah S; Ashfaq, Moetasim; White, Michael A; Jones, Gregory V

    2011-01-01

    Design and implementation of effective climate change adaptation activities requires quantitative assessment of the impacts that are likely to occur without adaptation, as well as the fraction of impact that can be avoided through each activity. Here we present a quantitative framework inspired by the greenhouse gas stabilization wedges of Pacala and Socolow. In our proposed framework, the damage avoided by each adaptation activity creates an 'adaptation wedge' relative to the loss that would occur without that adaptation activity. We use premium winegrape suitability in the western United States as an illustrative case study, focusing on the near-term period that covers the years 2000-39. We find that the projected warming over this period results in the loss of suitable winegrape area throughout much of California, including most counties in the high-value North Coast and Central Coast regions. However, in quantifying adaptation wedges for individual high-value counties, we find that a large adaptation wedge can be captured by increasing the severe heat tolerance, including elimination of the 50% loss projected by the end of the 2030-9 period in the North Coast region, and reduction of the projected loss in the Central Coast region from 30% to less than 15%. Increased severe heat tolerance can capture an even larger adaptation wedge in the Pacific Northwest, including conversion of a projected loss of more than 30% in the Columbia Valley region of Washington to a projected gain of more than 150%. We also find that warming projected over the near-term decades has the potential to alter the quality of winegrapes produced in the western US, and we discuss potential actions that could create adaptation wedges given these potential changes in quality. While the present effort represents an initial exploration of one aspect of one industry, the climate adaptation wedge framework could be used to quantitatively evaluate the opportunities and limits of climate adaptation

  19. Do running speed and shoe cushioning influence impact loading and tibial shock in basketball players?

    Directory of Open Access Journals (Sweden)

    Wing-Kai Lam

    2018-05-01

    Full Text Available Background Tibial stress fracture (TSF is a common injury in basketball players. This condition has been associated with high tibial shock and impact loading, which can be affected by running speed, footwear condition, and footstrike pattern. However, these relationships were established in runners but not in basketball players, with very little research done on impact loading and speed. Hence, this study compared tibial shock, impact loading, and foot strike pattern in basketball players running at different speeds with different shoe cushioning properties/performances. Methods Eighteen male collegiate basketball players performed straight running trials with different shoe cushioning (regular-, better-, and best-cushioning and running speed conditions (3.0 m/s vs. 6.0 m/s on a flat instrumented runway. Tri-axial accelerometer, force plate and motion capture system were used to determine tibial accelerations, vertical ground reaction forces and footstrike patterns in each condition, respectively. Comfort perception was indicated on a 150 mm Visual Analogue Scale. A 2 (speed × 3 (footwear repeated measures ANOVA was used to examine the main effects of shoe cushioning and running speeds. Results Greater tibial shock (P 0.14; η2 = 0.13. Discussion There may be an optimal band of shoe cushioning for better protection against TSF. These findings may provide insights to formulate rehabilitation protocols for basketball players who are recovering from TSF.

  20. TIBIAL PERIPROSTHETIC FRACTURE COMBINED WITH TIBIAL STEM STRESS FRACTURE FROM TOTAL KNEE ARTHROPLASTY

    OpenAIRE

    Fonseca, Fernando; Rebelo, Edgar; Completo, Antonio

    2011-01-01

    Total knee arthroplasty complications related to the prosthetic material are very rare, except for polyethylene wear. We report the case of a 58-year-old woman who came to the emergency service of our hospital with a periprosthetic tibial fracture (Mayo Clinic type I). Careful examination showed that this fracture was concomitantly associated with a tibial stem fatigue fracture. The prosthesis and the stem were sent to an independent biomechanics laboratory for evaluation. A finite-element CA...

  1. TIBIAL LANDMARKS IN ACL ANATOMIC REPAIR

    Directory of Open Access Journals (Sweden)

    M. V. Demesсhenko

    2016-01-01

    Full Text Available Purpose: to identify anatomical landmarks on tibial articular surface to serve as reference in preparing tibial canal with respect to the center of ACL footprint during single bundle arthroscopic repair.Materials and methods. Twelve frozen knee joint specimens and 68 unpaired macerated human tibia were studied using anatomical, morphometric, statistical methods as well as graphic simulation.Results. Center of the tibial ACL footprint was located 13,1±1,7 mm anteriorly from posterior border of intercondylar eminence, at 1/3 of the distance along the line connecting apexes of internal and external tubercles and 6,1±0,5 mm anteriorly along the perpendicular raised to this point.Conclusion. Internal and external tubercles, as well as posterior border of intercondylar eminence can be considered as anatomical references to determine the center of the tibial ACL footprint and to prepare bone canals for anatomic ligament repair.

  2. A posterior tibial tendon skipping rope

    NARCIS (Netherlands)

    van Sterkenburg, M. N.; Haverkamp, D.; van Dijk, C. N.; Kerkhoffs, G. M. M. J.

    2010-01-01

    This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord

  3. Incidence and epidemiology of tibial shaft fractures

    DEFF Research Database (Denmark)

    Larsen, Peter; Elsøe, Rasmus; Hansen, Sandra Hope

    2015-01-01

    Introduction: The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large....... The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have...... frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. Conclusion: This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type...

  4. Tibial shaft fractures in football players

    Directory of Open Access Journals (Sweden)

    Daisley Susan

    2007-06-01

    Full Text Available Abstract Background Football is officially the most popular sport in the world. In the UK, 10% of the adult population play football at least once a year. Despite this, there are few papers in the literature on tibial diaphyseal fractures in this sporting group. In addition, conflicting views on the nature of this injury exist. The purpose of this paper is to compare our experience of tibial shaft football fractures with the little available literature and identify any similarities and differences. Methods and Results A retrospective study of all tibial football fractures that presented to a teaching hospital was undertaken over a 5 year period from 1997 to 2001. There were 244 tibial fractures treated. 24 (9.8% of these were football related. All patients were male with a mean age of 23 years (range 15 to 29 and shin guards were worn in 95.8% of cases. 11/24 (45.8% were treated conservatively, 11/24 (45.8% by Grosse Kemp intramedullary nail and 2/24 (8.3% with plating. A difference in union times was noted, conservative 19 weeks compared to operative group 23.9 weeks (p Conclusion Our series compared similarly with the few reports available in the literature. However, a striking finding noted by the authors was a drop in the incidence of tibial shaft football fractures. It is likely that this is a reflection of recent compulsory FIFA regulations on shinguards as well as improvements in the design over the past decade since its introduction.

  5. Checking the virtual treatment modality Wedge from Siemens; Verificacion de la modalidad de tratamiento virtual WEDGE de SIEMENS

    Energy Technology Data Exchange (ETDEWEB)

    Suero Rodrigo, M. A.; Marques Fraguela, E.

    2011-07-01

    The treatment modality Virtual Wedge (VW) or implemented by Siemens virtual wedge in electron linear accelerators achieved dose distributions are similar but not identical, to those obtained with physical wedges. Among the advantages against the latter is the greater ease of use, wedge factor close to one, and lower peripheral dose. However, these benefits are to be effective requires a through quality control dependence because a larger number of parameters that control the generation of the beam, the dose monitor system and the movement of the jaws of the collimator. We performed a study of the wedge taking into account different configurations that can affect their behavior from the dosimetric point of view.

  6. Multiple Osteochondral Allograft Transplantation with Concomitant Tibial Tubercle Osteotomy for Multifocal Chondral Disease of the Knee.

    Science.gov (United States)

    Cotter, Eric J; Waterman, Brian R; Kelly, Mick P; Wang, Kevin C; Frank, Rachel M; Cole, Brian J

    2017-08-01

    Symptomatic patellofemoral chondral lesions are a challenging clinical entity, as these defects may result from persistent lateral patellar maltracking or repetitive microtrauma. Anteromedializing tibial tubercle osteotomy has been shown to be an effective strategy for primary and adjunctive treatment of focal or diffuse patellofemoral disease to improve the biomechanical loading environment. Similarly, osteochondral allograft transplantation has proven efficacy in physiologically young, high-demand patients with condylar or patellofemoral lesions, particularly without early arthritic progression. The authors present the surgical management of a young athlete with symptomatic tricompartmental focal chondral defects with fresh osteochondral allograft transplantation and anteromedializing tibial tubercle osteotomy.

  7. Filling Transitions in Acute and Open Wedges.

    Czech Academy of Sciences Publication Activity Database

    Malijevský, Alexandr; Parry, A.O.

    2015-01-01

    Roč. 91, č. 5 (2015), s. 052401 ISSN 1539-3755 R&D Projects: GA ČR GA13-09914S Grant - others:EPSRC(GB) EP/J009636/1; EPSRC(GB) EP/I019111/1 Institutional support: RVO:67985858 Keywords : wetting transitions * wedges * density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.288, year: 2014

  8. Comments related to infinite wedge representations

    OpenAIRE

    Grieve, Nathan

    2016-01-01

    We study the infinite wedge representation and show how it is related to the universal extension of $g[t,t^{-1}]$ the loop algebra of a complex semi-simple Lie algebra $g$. We also give an elementary proof of the boson-fermion correspondence. Our approach to proving this result is based on a combinatorial construction with partitions combined with an application of the Murnaghan-Nakayama rule.

  9. Elastic wave diffraction by infinite wedges

    Energy Technology Data Exchange (ETDEWEB)

    Fradkin, Larissa; Zernov, Victor [Sound Mathematics Ltd., Cambridge CB4 2AS (United Kingdom); Gautesen, Arthur [Mathematics Department, Iowa State University and Ames Laboratory (United States); Darmon, Michel, E-mail: l.fradkin@soundmathematics.com [CEA-LIST, CEA-Saclay, 91191 Gif-sur-Yvette (France)

    2011-01-01

    We compare two recently developed semi-analytical approaches to the classical problem of diffraction by an elastic two dimensional wedge, one based on the reciprocity principle and Fourier Transform and another, on the representations of the elastodynamic potentials in the form of Sommerfeld Integrals. At present, in their common region of validity, the approaches are complementary, one working better than the other at some isolated angles of incidence.

  10. Localization of observables in the Rindler wedge

    Science.gov (United States)

    Asorey, M.; Balachandran, A. P.; Marmo, G.; de Queiroz, A. R.

    2017-11-01

    One of the striking features of QED is that charged particles create a coherent cloud of photons. The resultant coherent state vectors of photons generate a nontrivial representation of the localized algebra of observables that do not support a representation of the Lorentz group: Lorentz symmetry is spontaneously broken. We show in particular that Lorentz boost generators diverge in this representation, a result shown also by Balachandran et al. [Eur. Phys. J. C 75, 89 (2015), 10.1140/epjc/s10052-015-3305-0] (see also the work by Balachandran et al. [Mod. Phys. Lett. A 28, 1350028 (2013), 10.1142/S0217732313500284]. Localization of observables, for example in the Rindler wedge, uses Poincaré invariance in an essential way [Int. J. Geom. Methods Mod. Phys. 14, 1740008 (2017)., 10.1142/S0219887817400084]. Hence, in the presence of charged fields, the photon observables cannot be localized in the Rindler wedge. These observations may have a bearing on the black hole information loss paradox, as the physics in the exterior of the black hole has points of resemblance to that in the Rindler wedge.

  11. Prolonged operative time increases infection rate in tibial plateau fractures.

    Science.gov (United States)

    Colman, Matthew; Wright, Adam; Gruen, Gary; Siska, Peter; Pape, Hans-Christoph; Tarkin, Ivan

    2013-02-01

    Fractures of the tibial plateau present a treatment challenge and are susceptible to both prolonged operative times and high postoperative infection rates. For those fractures treated with open plating, we sought to identify the relationship between surgical site infection and prolonged operative time as well as to identify other surgical risk factors. We performed a retrospective controlled analysis of 309 consecutive unicondylar and bicondylar tibial plateau fractures treated with open plate osteosynthesis at our institution's level I trauma centre during a recent 5-year period. We recorded operative times, injury characteristics, surgical treatment, and need for operative debridement due to infection. Operative times of infected cases were compared to uncomplicated surgical cases. Multivariable logistic regression analysis was performed to identify independent risk factors for postoperative infection. Mean operative time in the infection group was 2.8h vs. 2.2h in the non-infected group (p=0.005). 15 fractures (4.9%) underwent four compartment fasciotomies as part of their treatment, with a significantly higher infection rate than those not undergoing fasciotomy (26.7% vs. 6.8%, p=0.01). Open fracture grade was also significantly related to infection rate (closed fractures: 5.3%, grade 1: 14.3%, grade 2: 40%, grade 3: 50%, pinfection rates (13.9% vs. 8.7%, p=0.36). Multivariable logistic regression analysis of the entire study group identified longer operative times (OR 1.78, p=0.013) and open fractures (OR 7.02, psite infection. Operative times approaching 3h and open fractures are related to an increased overall risk for surgical site infection after open plating of the tibial plateau. Dual incision approaches with bicolumnar plating do not appear to expose the patient to increased risk compared to single incision approaches. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Proximal tibial osteophytes and their relationship with the height of the tibial spines of the intercondylar eminence: paleopathological study

    International Nuclear Information System (INIS)

    Hayeri, Mohammad Reza; Shiehmorteza, Masoud; Trudell, Debra J.; Resnick, Donald; Hefflin, Tori

    2010-01-01

    Tibial spiking (i.e., spurring of tibial spines), eburnation, and osteophytes are considered features of osteoarthritis. This investigation employed direct inspection of the medial and lateral tibial plateaus in paleopathological specimens to analyze the frequency and morphological features of osteoarthritis and to define any relationship between the size of osteophytes and that of the intercondylar tibial spines. A total of 35 tibial bone specimens were evaluated for the degree of osteoarthritis and presence of eburnation. Each plateau was also divided into four quadrants and the presence and size of bone outgrowths were recorded in each quadrant. The ''medial/lateral tibial intercondylar spine index'' for each specimen was calculated as follows: (medial/lateral intercondylar tibial spine height)/(anteroposterior width of the superior tibial surface). The relationships between medial and lateral tibial height indexes with the degree of osteoarthritis were then tested. Osteophytes were observed more frequently in the anterior quadrants of both tibial plateaus than in the posterior quadrants (29 vs 16 for the medial tibial plateau [p = 0.01] and 28 vs 20 for the lateral tibial plateau [p = 0.04]). Eburnation was seen more frequently in the posterior regions of both tibial plateaus than in the anterior regions (17 vs 5, p < 0.01). In specimens with no signs of osteoarthritis the lateral intercondylar tibial index was significantly lower than that in specimens with some degree of osteoarthritis (p = 0.02). The medial intercondylar tibial index of the specimens with no signs of osteoarthritis was not significantly different from that of the specimens with some degree of osteoarthritis (p = 0.45). There was a positive correlation between the lateral spine height index and the overall grading of osteoarthritis, (r = 0.6, p < 0.01). In the anteromedial and posteromedial quadrants of the lateral tibial plateau, the association between the lateral intercondylar tibial spine

  13. Proximal tibial osteophytes and their relationship with the height of the tibial spines of the intercondylar eminence: paleopathological study

    Energy Technology Data Exchange (ETDEWEB)

    Hayeri, Mohammad Reza [Children' s National Medical Center, Department of Radiology, Washington, DC (United States); Shiehmorteza, Masoud; Trudell, Debra J.; Resnick, Donald [University of California San Diego, Department of Radiology, San Diego, CA (United States); Hefflin, Tori [Museum of Man San Diego, San Diego, CA (United States)

    2010-09-15

    Tibial spiking (i.e., spurring of tibial spines), eburnation, and osteophytes are considered features of osteoarthritis. This investigation employed direct inspection of the medial and lateral tibial plateaus in paleopathological specimens to analyze the frequency and morphological features of osteoarthritis and to define any relationship between the size of osteophytes and that of the intercondylar tibial spines. A total of 35 tibial bone specimens were evaluated for the degree of osteoarthritis and presence of eburnation. Each plateau was also divided into four quadrants and the presence and size of bone outgrowths were recorded in each quadrant. The ''medial/lateral tibial intercondylar spine index'' for each specimen was calculated as follows: (medial/lateral intercondylar tibial spine height)/(anteroposterior width of the superior tibial surface). The relationships between medial and lateral tibial height indexes with the degree of osteoarthritis were then tested. Osteophytes were observed more frequently in the anterior quadrants of both tibial plateaus than in the posterior quadrants (29 vs 16 for the medial tibial plateau [p = 0.01] and 28 vs 20 for the lateral tibial plateau [p = 0.04]). Eburnation was seen more frequently in the posterior regions of both tibial plateaus than in the anterior regions (17 vs 5, p < 0.01). In specimens with no signs of osteoarthritis the lateral intercondylar tibial index was significantly lower than that in specimens with some degree of osteoarthritis (p = 0.02). The medial intercondylar tibial index of the specimens with no signs of osteoarthritis was not significantly different from that of the specimens with some degree of osteoarthritis (p = 0.45). There was a positive correlation between the lateral spine height index and the overall grading of osteoarthritis, (r = 0.6, p < 0.01). In the anteromedial and posteromedial quadrants of the lateral tibial plateau, the association between the lateral

  14. Investigation of turbulent wedges generated by different single surface roughness elements

    Science.gov (United States)

    Traphan, Dominik; Meinlschmidt, Peter; Lutz, Otto; Peinke, Joachim; Gülker, Gerd

    2013-11-01

    It is known that small faults on rotor blades of wind turbines can cause significant power loss. In order to better understand the governing physical effects, in this experimental study, the formation of a turbulent wedge over a flat plate induced by single surface roughness elements is under investigation. The experiments are performed at different ambient pressure gradients, thus allowing conclusions about the formation of a turbulent wedge over an airfoil. With respect to typical initial faults on operating airfoils, the roughness elements are modified in both size and shape (raised or recessed). None intrusive experimental methods, such as stereoscopic PIV and LDA, enable investigations based on temporally and spatially highly resolved velocity measurements. In this way, a spectral analysis of the turbulent boundary layer is performed and differences in coherent structures within the wedge are identified. These findings are correlated with global measurements of the wedge carried out by infrared thermography. This correlation aims to enable distinguishing the cause and main properties of a turbulent wedge by the easy applicable method of infrared thermography, which is of practical relevance in the field of condition monitoring of wind turbines.

  15. [Application of tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty].

    Science.gov (United States)

    Li, Guoliang; Han, Guangpu; Zhang, Jinxiu; Ma, Shiqiang; Guo, Donghui; Yuan, Fulu; Qi, Bingbing; Shen, Runbin

    2013-07-01

    To explore the application value of self-made tibial mechanical axis locator in tibial extra-articular deformity in total knee arthroplasty (TKA) for improving the lower extremity force line. Between January and August 2012, 13 cases (21 knees) of osteoarthritis with tibial extra-articular deformity were treated, including 5 males (8 knees) and 8 females (13 knees) with an average age of 66.5 years (range, 58-78 years). The disease duration was 2-5 years (mean, 3.5 years). The knee society score (KSS) was 45.5 +/- 15.5. Extra-articular deformities included 1 case of knee valgus (2 knees) and 12 cases of knee varus (19 knees). Preoperative full-length X-ray films of lower extremities showed 10-21 degrees valgus or varus deformity of tibial extra joint. Self-made tibial mechanical axis locator was used to determine and mark coronal tibial mechanical axis under X-ray before TKA, and then osteotomy was performed with extramedullary positioning device according to the mechanical axis marker.' All incisions healed by first intention, without related complications of infection and joint instability. All patients were followed up 5-12 months (mean, 8.3 months). The X-ray examination showed case of 2.9 degrees knee deviation angle at 3 days after operation, and the accurate rate was 95.2%. No loosening or instability of prosthesis occurred during follow-up. KSS score was 85.5 +/- 15.0 at last follow-up, showing significant difference when compared with preoperative score (t=12.82, P=0.00). The seft-made tibial mechanical axis locator can improve the accurate rate of the lower extremity force line in TKA for tibia extra-articular deformity.

  16. Assessment of an amorphous silicon EPID for quality assurance of enhanced dynamic wedge

    International Nuclear Information System (INIS)

    Greer, P.

    2004-01-01

    measurements made with an ionisation chamber under the same conditions. The reproducibility of the EPID measured wedge-factors was determined by comparing three weekly measurement results. EPID profiles measured were in good agreement (within 5%) of Profiler measurements for both wedge angles and all field sizes. The EPID profiles had flood-field corrections removed to give the raw-response of the EPID system. Normalised EPID 60 deg wedge profiles measured at weekly intervals were within 0.5% of each other excluding the penumbra region. The EPID measured wedge-factors are shown. These were all within 0.6% of the mean result from routine weekly ion-chamber measurements. The standard deviation of the three measurements was 0.27% which is similar to the standard deviation of the routine ion-chamber measurements of 0.4%. The amorphous silicon EPID is highly suited to routine quality assurance of EDW. Measurements of both wedge-factors and wedge profiles are accurate and reproducible. The quality assurance measurements can be made in a matter of a few minutes, with virtually no experimental set-up time. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  17. Baseline Vitamin D Status is Predictive of Longitudinal Change in Tibial BMD in Knee Osteoarthritis (OA)

    Science.gov (United States)

    With its lack of effective treatment and high prevalence, the public health impact of OA is substantial. Peri-articular bone in OA can be evaluated with the medial:lateral tibial BMD ratio (M:L BMD) obtained from dual x-ray absorptiometry (DXA). Higher M:L BMD is associated with medial OA features...

  18. Observation of the dispersion of wedge waves propagating along cylinder wedge with different truncations by laser ultrasound technique

    Science.gov (United States)

    Jia, Jing; Zhang, Yu; Han, Qingbang; Jing, Xueping

    2017-10-01

    The research focuses on study the influence of truncations on the dispersion of wedge waves propagating along cylinder wedge with different truncations by using the laser ultrasound technique. The wedge waveguide models with different truncations were built by using finite element method (FEM). The dispersion curves were obtained by using 2D Fourier transformation method. Multiple mode wedge waves were observed, which was well agreed with the results estimated from Lagasse's empirical formula. We established cylinder wedge with radius of 3mm, 20° and 60°angle, with 0μm, 5μm, 10μm, 20μm, 30μm, 40μm, and 50μm truncations, respectively. It was found that non-ideal wedge tip caused abnormal dispersion of the mode of cylinder wedge, the modes of 20° cylinder wedge presents the characteristics of guide waves which propagating along hollow cylinder as the truncation increasing. Meanwhile, the modes of 60° cylinder wedge with truncations appears the characteristics of guide waves propagating along hollow cylinder, and its mode are observed clearly. The study can be used to evaluate and detect wedge structure.

  19. Biomechanical Factors in Tibial Stress Fracture

    Science.gov (United States)

    2001-08-01

    Relationship between Loading Rates and Tibial Accelerometry in Forefoot Strike Runners. Presented at the Annual American Society of Biomechanics Mtg...of the APTA, Seattle, WA, 2/99. McClay, IS, Williams, DS, and Manal, KT. Lower Extremity Mechanics of Runners with a Converted Forefoot Strike ...Management, Inc, 1998-1999 The Effect of Different Orthotic Devices on Lower Extremity Mechanics of Rearfoot and Forefoot Strikers, $3,500. Foot Management

  20. Anterior Tibial Artery Pseudoaneurysm: Case Report

    Directory of Open Access Journals (Sweden)

    Funda Tor

    2012-06-01

    Full Text Available The aneurysmsatic changes of the infrapopliteal arteries are rarely seen. They are pseudoaneurysms rather than true aneursyms. The most important cause of them is trauma. There is not a standart treatment for infrapopliteal aneursyms. In this study, we have evaluated a case operated for anterior tibial artery pseudoaneurysm developed after penetrant trauma and diagnosed two weeks later. [Cukurova Med J 2012; 37(3.000: 172-175

  1. Dysplasia epiphysealis hemimelica of the tibial tubercle

    Energy Technology Data Exchange (ETDEWEB)

    Thacker, M.M.; Scully, S.P.; Pitcher, J.D.; Temple, H. Thomas [University of Miami, Department of Orthopedics and Rehabilitation, FL (United States); Azouz, E.M. [University of Miami, Department of Radiology, FL (United States)

    2006-03-15

    Dysplasia epiphysealis hemimelica (DEH) is a rare skeletal dysplasia with epiphyseal involvement first described by Mouchet and Belot in 1926. Lower extremity involvement is common and might involve a single or multiple epiphyses in the affected extremity. We report an unusual case of involvement of the tibial tubercle in a girl aged 4 years 8 months, and we present the clinical, radiographic and pathologic findings. We discuss the role of MRI in the diagnosis and treatment plan. (orig.)

  2. Contemporary sand wedge development in seasonally frozen ground and paleoenvironmental implications

    Science.gov (United States)

    Wolfe, Stephen A.; Morse, Peter D.; Neudorf, Christina M.; Kokelj, Steven V.; Lian, Olav B.; O'Neill, H. Brendan

    2018-05-01

    Contemporary sand wedges and sand veins are active in seasonally frozen ground within the extensive discontinuous permafrost zone in Northwest Territories, Canada. The region has a subarctic continental climate with 291 mm a-1 precipitation, -4.1 °C mean annual air temperature, warm summers (July mean 17.0 °C), and cold winters (January mean -26.6 °C). Five years of continuous observations indicate that interannual variation of the ground thermal regime is dominantly controlled by winter air temperature and snow cover conditions. At sandy sites, thin snow cover and high thermal conductivity promote rapid freezing, high rates of ground cooling, and low near-surface ground temperatures (-15 to -25 °C), resulting in thermal contraction cracking to depths of 1.2 m. Cracking potentials are high in sandy soils when air temperatures are air temperatures are ≤-17 °C, and snow cover is conditions in peatlands maintain permafrost, but thermal contraction cracking does not occur because thicker snow cover and the thermal properties of peat prolong freezeback and maintain higher winter ground temperatures. A combination of radiocarbon dating, optical dating, and stratigraphic observations were used to differentiate sand wedge types and formation histories. Thermal contraction cracks that develop in the sandy terrain are filled by surface (allochthonous) and/or host (autochthonous) material during the thaw season. Epigenetic sand wedges infilled with allochthonous sand develop within former beach sediments beneath an active eolian sand sheet. Narrower and deeper syngenetic wedges developed within aggrading eolian sand sheets, whereas wider and shallower antisyngenetic wedges developed in areas of active erosion. Thermal contraction cracking beneath vegetation-stabilized surfaces leads to crack infilling by autochthonous host and overlying organic material, with resultant downturning and subsidence of adjacent strata. Sand wedge development in seasonally frozen ground

  3. Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture

    International Nuclear Information System (INIS)

    Khan, I.; Javed, S.; Khan, G.N.; Aziz, A.

    2013-01-01

    Objective: To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Study Design: Case series. Place and Duration of Study: Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Methodology: Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Results: Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Conclusion: Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function. (author)

  4. Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture.

    Science.gov (United States)

    Khan, Irfanullah; Javed, Shahzad; Khan, Gauhar Nawaz; Aziz, Amer

    2013-03-01

    To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Case series. Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function.

  5. Systematic radiographic evaluation of tibial hemimelia with orthopedic implications

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan-List, Katia [Rochester General Hospital, Department of Diagnostic Imaging, Rochester, NY (United States); Klionsky, Nina B. [University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY (United States); Golisano Children' s Hospital, Department of Radiology, Rochester, NY (United States); Sanders, James O. [University of Rochester Medical Center, School of Medicine and Dentistry, Rochester, NY (United States); Golisano Children' s Hospital, Department of Orthopaedics, Rochester, NY (United States); Golisano Children' s Hospital, Department of Pediatrics, Rochester, NY (United States); Katz, Michael E. [St. Mary' s Medical Center and Palm Beach Children' s Hospital, Department of Radiology, West Palm Beach, FL (United States)

    2017-04-15

    Tibial hemimelia is a rare lower-extremity pre-axial longitudinal deficiency characterized by complete or partial absence of the tibia. The reported incidence is 1 in 1 million live births. In this pictorial essay, we define tibial hemimelia and describe associated conditions and principles of preoperative imaging assessment for a child with tibial hemimelia. We also indicate the imaging findings that might influence the choice of treatment, describe the most widely used classification systems, and briefly discuss current treatment approaches. (orig.)

  6. Systematic radiographic evaluation of tibial hemimelia with orthopedic implications

    International Nuclear Information System (INIS)

    Kaplan-List, Katia; Klionsky, Nina B.; Sanders, James O.; Katz, Michael E.

    2017-01-01

    Tibial hemimelia is a rare lower-extremity pre-axial longitudinal deficiency characterized by complete or partial absence of the tibia. The reported incidence is 1 in 1 million live births. In this pictorial essay, we define tibial hemimelia and describe associated conditions and principles of preoperative imaging assessment for a child with tibial hemimelia. We also indicate the imaging findings that might influence the choice of treatment, describe the most widely used classification systems, and briefly discuss current treatment approaches. (orig.)

  7. Forces in Motzkin paths in a wedge

    International Nuclear Information System (INIS)

    Janse van Rensburg, E J

    2006-01-01

    Entropic forces in models of Motzkin paths in a wedge geometry are considered as models of forces in polymers in confined geometries. A Motzkin path in the square lattice is a path from the origin to a point in the line Y = X while it never visits sites below this line, and it is constrained to give unit length steps only in the north and east directions and steps of length √2 in the north-east direction. Motzkin path models may be generalized to ensembles of NE-oriented paths above the line Y = rX, where r > 0 is an irrational number. These are paths giving east, north and north-east steps from the origin in the square lattice, and confined to the r-wedge formed by the Y-axis and the line Y = rX. The generating function g r of these paths is not known, but if r > 1, then I determine its radius of convergence to be t r = min (r-1)/r≤y≤r/(r+1) [y y (1-r(1-y)) 1-r(1-y) (r(1-y)-y) r(1-y)-y ] and if r is an element of (0, 1), then t r = 1/3. The entropic force the path exerts on the line Y rX may be computed from this. An asymptotic expression for the force for large values of r is given by F(r) = log(2r)/r 2 - (1+2log(2r))/2r 3 + O (log(2r)/r 4 ). In terms of the vertex angle α of the r-wedge, the moment of the force about the origin has leading terms F(α) log(2/α) - (α/2)(1+2log(2/α)) + O(α 2 log(2/α)) as α → 0 + and F(α) = 0 if α is element of [π/4, π/2]. Moreover, numerical integration of the force shows that the total work done by closing the wedge is 1.085 07... lattice units. An alternative ensemble of NE-oriented paths may be defined by slightly changing the generating function g r . In this model, it is possible to determine closed-form expressions for the limiting free energy and the force. The leading term in an asymptotic expansions for this force agrees with the leading term in the asymptotic expansion of the above model, and the subleading term only differs by a factor of 2

  8. Radiographic quantitative assessment of cranial tibial subluxation before and after tibial plateau leveling osteotomy in dogs.

    Science.gov (United States)

    Kim, Stanley E; Lewis, Daniel D; Pozzi, Antonio; Seibert, Rachel L; Winter, Matthew D

    2011-03-01

    To determine the influence of stifle joint flexion angle, cranial cruciate ligament (CrCL) integrity, tibial plateau leveling osteotomy (TPLO), and cranial tibial subluxation on the distance between the location of the origin and insertion of the CrCL (CrCL(d)) in dogs. 4 pairs of pelvic limbs from adult dog cadavers weighing 23 to 34 kg. Procedures-Mediolateral projection radiographs of each stifle joint were obtained with the joint flexed at 90°, 105°, 120°, 135°, and 150°. Radiopaque markers were then placed at the sites of origin and insertion of the CrCL. Afterward, radiography was repeated in the same manner, before and after CrCL transection, with and without TPLO. Following CrCL transection, radiographs were obtained before and after inducing overt cranial tibial subluxation. Interobserver variation in measuring the CrCL(d) without fiduciary markers was assessed. The effect of CrCL integrity, cranial tibial subluxation, flexion angle, and TPLO on CrCL(d) was also determined. Interobserver agreement was strong, with an intraclass correlation coefficient of 0.859. The CrCL(d) was significantly shorter (Cranial tibial subluxation caused a 25% to 40% increase in CrCL(d). No effect of TPLO on CrCL(d) was found, regardless of CrCL integrity, forced stifle joint subluxation, or flexion angle. Overt cranial tibial subluxation in CrCL-deficient stifle joints can be detected on mediolateral projection radiographs by comparing CrCL(d) on neutral and stressed joint radiographs at joint angles between 105° and 150°, regardless of whether a TPLO has been performed.

  9. Wedge geometry, frictional properties and interseismic coupling of the Java megathrust

    Science.gov (United States)

    Koulali, Achraf; McClusky, Simon; Cummins, Phil; Tregoning, Paul

    2018-06-01

    The mechanical interaction between rocks at fault zones is a key element for understanding how earthquakes nucleate and propagate. Therefore, estimating frictional properties along fault planes allows us to infer the degree of elastic strain accumulation throughout the seismic cycle. The Java subduction zone is an active plate boundary where high seismic activity has long been documented. However, very little is known about the seismogenic processes of the megathrust, especially its shallowest portion where onshore geodetic networks are insensitive to recover the pattern of elastic strain. Here, we use the geometry of the offshore accretionary prism to infer frictional properties along the Java subduction zone, using Coulomb critical taper theory. We show that large portions of the inner wedge in the eastern part of the Java subduction megathrust are in a critical state, where the wedge is on the verge of failure everywhere. We identify four clusters with an internal coefficient of friction μint of ∼ 0.8 and hydrostatic pore pressure within the wedge. The average effective coefficient of friction ranges between 0.3 and 0.4, reflecting a strong décollement. Our results also show that the aftershock sequence of the 1994 Mw 7.9 earthquake halted adjacent to a critical segment of the wedge, suggesting that critical taper wedge areas in the eastern Java subduction interface may behave as a permanent barrier to large earthquake rupture. In contrast, in western Java topographic slope and slab dip profiles suggest that the wedge is mechanically stable, i.e deformation is restricted to sliding along the décollement, and likely to coincide with a seismogenic portion of the megathrust. We discuss the seismic hazard implications and highlight the importance of considering the segmentation of the Java subduction zone when assessing the seismic hazard of this region.

  10. Cementless Hip Stem Anteversion in the Dysplastic Hip: A Comparison of Tapered Wedge vs Metaphyseal Filling.

    Science.gov (United States)

    Taniguchi, Naofumi; Jinno, Tetsuya; Koga, Daisuke; Hagino, Tetsuo; Okawa, Atsushi; Haro, Hirotaka

    2017-05-01

    Appropriate stem anteversion is important for achieving stability of the prosthetic joint in total hip arthroplasty. Anteversion of a cementless femoral stem is affected by the femoral canal morphology and varies according to stem geometry. We investigated the difference and variation of the increase in anteversion between 2 types of cementless stems, and the correlation between each stem and the preoperative femoral anteversion. We retrospectively compared 2 groups of hips that underwent total hip arthroplasty using a metaphyseal filling stem (78 hips) or a tapered wedge stem (83 hips). All the patients had osteoarthritis due to hip dysplasia. Computed tomography was used to measure preoperative femoral anteversion at 5 levels and postoperative stem anteversion. The increase in anteversion of the tapered wedge stem group (22.7° ± 11.6°) was more than that of the metaphyseal filling stem group (17.2° ± 8.3°; P = .0007). The variation of the increase in the tapered wedge stem group was significantly larger than that in the metaphyseal filling stem group (P = .0016). The metaphyseal filling stem group was more highly and positively correlated with femoral anteversion than the tapered wedge stem group. Femoral anteversion affects stem anteversion differently according to stem geometry. The tapered wedge stems had greater variation of the increase in anteversion than did the metaphyseal filling stems. Based on the results of this study, it is difficult to preoperatively estimate the increase in stem anteversion for tapered wedge stems. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Arthroscopic guided biopsy and radiofrequency thermoablation of a benign neoplasm of the tibial spines area: a treatment option

    Directory of Open Access Journals (Sweden)

    Zoccali Carmine

    2012-04-01

    Full Text Available Abstract Background Lesions located in the area of the tibial spines are rare. In most cases, treatment follows histological diagnosis, but when imaging and clinical data are considered to be "very" characteristic for benign lesions, such as chondroblastoma or osteoid osteoma, treatment may be performed without biopsy. Traditional curettage requires opening the joint, which presents a high risk of contamination of the joint itself and surrounding structures, such as the popliteal area, with possible contamination of the neurovascular bundle when performing curettage with the posterior approach. In this case, the re-excision of a local recurrence would be extremely difficult. Results We describe a technique using arthroscopic guidance for radiofrequency thermoablation of a benign lesion in the tibial spines area. We report on an illustrative case. The patient so treated, reported immediate relief from the pain, and after two weeks, was free of pain. The biopsy performed before the treatment confirmed the radiological diagnosis of chondroblastoma. At one year of follow-up, the patient is without pain, with a 0-130°range of motion, has no activity limitations and is apparently free of disease. Conclusion This technique allows a radiofrequency thermoablation of a lesion in the tibial spines area and in the posterior tibial surface to be performed without opening the joint, monitoring the tibial plateau surface, probably decreasing the risk of cartilage damage. Unfortunately, in the case presented, the high pressure from the arthroscopy's pump broke the tibial plateau surface creating a communication to the tibial tunnel used for thermoablation.

  12. Strain measurements of the tibial insert of a knee prosthesis using a knee motion simulator.

    Science.gov (United States)

    Sera, Toshihiro; Iwai, Yuya; Yamazaki, Takaharu; Tomita, Tetsuya; Yoshikawa, Hideki; Naito, Hisahi; Matsumoto, Takeshi; Tanaka, Masao

    2017-12-01

    The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3-2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.

  13. Minimally-invasive plate osteosynthesis in distal tibial fractures: Results and complications.

    Science.gov (United States)

    Vidović, Dinko; Matejčić, Aljoša; Ivica, Mihovil; Jurišić, Darko; Elabjer, Esmat; Bakota, Bore

    2015-11-01

    Distal tibial or pilon fractures are usually the result of combined compressive and shear forces, and may result in instability of the metaphysis, with or without articular depression, and injury to the soft tissue. The complexity of injury, lack of muscle cover and poor vascularity make these fractures difficult to treat. Surgical treatment of distal tibial fractures includes several options: external fixation, IM nailing, ORIF and minimally-invasive plate osteosynthesis (MIPO). Management of distal tibial fractures with MIPO enables preservation of soft tissue and remaining blood supply. This is a report of a series of prospectively studied closed distal tibial and pilon fractures treated with MIPO. A total of 21 patients with closed distal tibial or pilon fractures were enrolled in the study between March 2008 and November 2013 and completed follow-up. Demographic characteristics, mechanism of injury, time required for union, ankle range of motion and complications were recorded. Fractures were classified according to the AO/OTA classification. Nineteen patients were initially managed with an ankle-spanning external fixator. When the status of the soft tissue had improved and swelling had subsided enough, a definitive internal fixation with MIPO was performed. Patients were invited for follow-up examinations at 3 and 6 weeks and then at intervals of 6 to 8 weeks until 12 months. Mean age of the patients was 40.1 years (range 19-67 years). Eighteen cases were the result of high-energy trauma and three were the result of low-energy trauma. According to the AO/OTA classification there were extraarticular and intraarticular fractures, but only simple articular patterns without depression or comminution. The average time for fracture union was 19.7 weeks (range 12-38 weeks). Mean range of motion was 10° of dorsiflexion (range 5-15°) and 28.3° of plantar flexion (range 20-35°). Three cases were metalwork-related complications. Two patients underwent plate removal

  14. Surface Geophysical Measurements for Locating and Mapping Ice-Wedges

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Larsen, S.H.

    2012-01-01

    to test the applicability of DC electrical resistivity tomography (ERT) and Ground Penetrating Radar (GPR) to identifying and mapping ice-wedge occurrences. The site is located in Central West Greenland, and the ice-wedges are found in a permafrozen peat soil with an active layer of about 30 cm. ERT...

  15. Beam profiles in the nonwedged direction for dynamic wedges

    International Nuclear Information System (INIS)

    Lydon, J.M.; Rykers, K.L.

    1996-01-01

    One feature of the dynamic wedge is the improved flatness of the beam profile in the nonwedged direction when compared to fixed wedges. Profiles in the nonwedged direction for fixed wedges show a fall-off in dose away from the central axis when compared to the open field profile. This study will show that there is no significant difference between open field profiles and nonwedged direction profiles for dynamically wedged beams. The implications are that the dynamic wedge offers an improved dose distribution in the nonwedged direction that can be modelled by approximating the dynamically wedged field to an open field. This is possible as both the profiles and depth doses of the dynamically wedged fields match those of the open fields, if normalized to d max of the same field size. For treatment planning purposes the effective wedge factor (EWF) provides a normalization factor for the open field depth dose data set. Data will be presented to demonstrate that the EWF shows relatively little variation with depth and can be treated as being independent of field size in the nonwedged direction. (author)

  16. Anterior cruciate ligament reconstruction with tibial attachment preserving hamstring graft without implant on tibial side

    Directory of Open Access Journals (Sweden)

    Skand Sinha

    2018-01-01

    Full Text Available Background: Tibial attachment preserving hamstring graft could prevent potential problems of free graft in anterior cruciate ligament (ACL reconstruction such as pull out before graft-tunnel healing or rupture before ligamentization. Different implants have been reportedly used for tibial side fixation with this technique. We investigated short-term outcome of ACL reconstruction (ACLR with tibial attachment sparing hamstring graft without implant on the tibial side by outside in technique. Materials and Methods: Seventy nine consecutive cases of ACL tear having age of 25.7 ± 6.8 years were included after Institutional Board Approval. All subjects were male. The mean time interval from injury to surgery was of 7.5 ± 6.4 months. Hamstring tendons were harvested with open tendon stripper leaving the tibial insertion intact. The free ends of the tendons were whip stitched, quadrupled, and whip stitched again over the insertion site of hamstring with fiber wire (Arthrex. Single bundle ACLR was done by outside in technique and the femoral tunnel was created with cannulated reamer. The graft was pulled up to the external aperture of femoral tunnel and fixed with interference screw (Arthrex. The scoring was done by Lysholm, Tegner, and KT 1000 by independent observers. All cases were followed up for 2 years. Results: The mean length of quadrupled graft attached to tibia was 127.65 ± 7.5 mm, and the mean width was 7.52 ± 0.78 mm. The mean preoperative Lysholm score of 47.15 ± 9.6, improved to 96.8 ± 2.4 at 1 year. All cases except two returned to the previous level of activity after ACLR. There was no significant difference statistically between preinjury (5.89 ± 0.68 and postoperative (5.87 ± 0.67 Tegner score. The anterior tibial translation (ATT (KT 1000 improved from 11.44 ± 1.93 mm to 3.59 ± 0.89 mm. The ATT of operated knee returned to nearly the similar value as of the opposite knee (3.47 ± 1.16 mm. The Pivot shift test was negative in

  17. The Valgus Inclination of the Tibial Component Increases the Risk of Medial Tibial Condylar Fractures in Unicompartmental Knee Arthroplasty.

    Science.gov (United States)

    Inoue, Shinji; Akagi, Masao; Asada, Shigeki; Mori, Shigeshi; Zaima, Hironori; Hashida, Masahiko

    2016-09-01

    Medial tibial condylar fractures (MTCFs) are a rare but serious complication after unicompartmental knee arthroplasty. Although some surgical pitfalls have been reported for MTCFs, it is not clear whether the varus/valgus tibial inclination contributes to the risk of MTCFs. We constructed a 3-dimensional finite elemental method model of the tibia with a medial component and assessed stress concentrations by changing the inclination from 6° varus to 6° valgus. Subsequently, we repeated the same procedure adding extended sagittal bone cuts of 2° and 10° in the posterior tibial cortex. Furthermore, we calculated the bone volume that supported the tibial component, which is considered to affect stress distribution in the medial tibial condyle. Stress concentrations were observed on the medial tibial metaphyseal cortices and on the anterior and posterior tibial cortices in the corner of cut surfaces in all models; moreover, the maximum principal stresses on the posterior cortex were larger than those on the anterior cortex. The extended sagittal bone cuts in the posterior tibial cortex increased the stresses further at these 3 sites. In the models with a 10° extended sagittal bone cut, the maximum principal stress on the posterior cortex increased as the tibial inclination changed from 6° varus to 6° valgus. The bone volume decreased as the inclination changed from varus to valgus. In this finite element method, the risk of MTCFs increases with increasing valgus inclination of the tibial component and with increased extension of the sagittal cut in the posterior tibial cortex. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Intrinsic factors associated with medial tibial stress syndrome in ...

    African Journals Online (AJOL)

    Intrinsic factors associated with medial tibial stress syndrome in athletes: A large case-control study. ... Medial tibial stress syndrome (MTSS) is the most common lower-leg injury in athletes, and is thought to be caused by ... from 32 Countries:.

  19. The soleal line: a cause of tibial pseudoperiostitis.

    Science.gov (United States)

    Levine, A H; Pais, M J; Berinson, H; Amenta, P S

    1976-04-01

    An unusually prominent soleal line (a normal anatomic variant) may mimic periosteal reaction along the posterior margin of the proximal tibial shaft. This area of pseudoperiostitis is differentiated from hyperostoses arising from the anterior tibial tubercle and the interosseous membrane. It is always associated with normal, undisturbed architecture of the underlying bone.

  20. Coverage of extensive tibial bone exposure in burn patients with ...

    African Journals Online (AJOL)

    Covering tibial bone exposure from third degree burns to the lower limbs is a challenging task for the plastic surgeon. We present our experience of covering tibial exposure from burns in three different patients, where four limbs were involved and three muscular flaps were used in conjunction with one another; i.e. the ...

  1. Tax wedge in Croatia, Austria, Hungary, Poland and Greece

    Directory of Open Access Journals (Sweden)

    Marin Onorato

    2016-06-01

    Full Text Available The aim of this paper is to compare the tax burden on labour income in Croatia, Austria, Greece, Hungary and Poland in 2013. The Taxing Wages methodology has been applied to hypothetical units across a range of gross wages in order to calculate net average tax wedge, net average tax rate, as well as other relevant indicators. When it comes to single workers without children, the smallest tax wedge for workers earning less than the average gross wage was found in Croatia, while Poland had the smallest tax wedge for above-average wages. Due to a progressive PIT system, the tax wedge for a single worker in Croatia reaches 50% at 400% of the average gross wage, equalling that of Austria, Greece and Hungary. Tax wedges for couples with two children show a similar trend.

  2. Therapeutical Management of the Tibial Plateau Fractures

    Directory of Open Access Journals (Sweden)

    Obada B.

    2016-11-01

    Full Text Available The study was aimed to identify the role of surgical treatment of tibial plateau fractures, its functional outcome and complications. Demographic data for the patients and details of current clinical and radiological follow-up findings were obtained to assess range of motion, clinical stability, alignment of the knee, and posttraumatic arthrosis (Kellgren/Lawrence score. 64 cases of tibial plateau fractures treated by different surgical methods and variuos implants type were studied from 2013 to 2015 and followed-up for minimum period of 6 months. The systematisation of the casuitry was made using Schatzker and AO classifications. The treatment methods consist of: percutaneous cannulated cancellous screws, ORIF with buttress plate with or without bone grafting, locking or nonlocking plates, external fixator. As complications we found: redepression 4 case, malunion 2 cases, knee stiffness 9, wound dehiscence in 1 cases and non-union or infection in none of our cases. The average flexion of the injured knee was significantly lower in comparison with the contralateral side (124.9°/135.2°. Knee stability did not differ statistically significantly. There were no signs of posttraumatic arthrosis in 45% of cases, mild signs in 30%, clear signs in 18%, and severe signs in 7%. As conclusion we found that surgical management of tibial plateau fractures will give excellent anatomical reduction and rigid fixation to restore articular congruity, facilitate early motion and reduce arthrosis risk and hence to achieve optimal knee function. The choice of optimal surgical methods, proper approach and implant is made in relation to fracture type according Schatzker and AO classification.

  3. Effects of counteracting external valgus moment on lateral tibial cartilage contact conditions and tibial rotation.

    Science.gov (United States)

    Shriram, Duraisamy; Parween, Rizuwana; Lee, Yee Han Dave; Subburaj, Karupppasamy

    2017-07-01

    Knee osteoarthritis that prevalently occurs at the medial compartment is a progressive chronic disorder affecting the articular cartilage of the knee joint, and lead to loss of joint functionality. Valgus braces have been used as a treatment procedure to unload the medial compartment for patients with medial osteoarthritis. Valgus braces through the application of counteracting external valgus moment shift the load from medial compartment towards the lateral compartment. Previous biomechanical studies focused only on the changes in varus moments before and after wearing the brace. The objective of this study was to investigate the influence of opposing external valgus moment applied by knee braces on the lateral tibial cartilage contact conditions using a 3D finite element model of the knee joint. Finite element simulations were performed on the knee joint model without and with the application of opposing valgus moment to mimic the unbraced and braced conditions. Lateral tibial cartilage contact pressures and contact area, and tibial rotation (varus-valgus and internal-external) were estimated for the complete walking gait cycle. The opposing valgus moment increased the maximum contact pressure and contact area on the lateral tibial cartilage compared to the normal gait moment. A peak contact pressure of 8.2 MPa and maximum cartilage loaded area of 28% (loaded cartilage nodes) on the lateral cartilage with the application of external valgus moment were induced at 50% of the gait cycle. The results show that the use of opposing valgus moment may significantly increase the maximum contact pressures and contact area on the lateral tibial cartilage and increases the risk of articular cartilage damage on the lateral compartment.

  4. Two-dimensional electronic spectroscopy with birefringent wedges

    Energy Technology Data Exchange (ETDEWEB)

    Réhault, Julien; Maiuri, Margherita; Oriana, Aurelio; Cerullo, Giulio [IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2014-12-15

    We present a simple experimental setup for performing two-dimensional (2D) electronic spectroscopy in the partially collinear pump-probe geometry. The setup uses a sequence of birefringent wedges to create and delay a pair of phase-locked, collinear pump pulses, with extremely high phase stability and reproducibility. Continuous delay scanning is possible without any active stabilization or position tracking, and allows to record rapidly and easily 2D spectra. The setup works over a broad spectral range from the ultraviolet to the near-IR, it is compatible with few-optical-cycle pulses and can be easily reconfigured to two-colour operation. A simple method for scattering suppression is also introduced. As a proof of principle, we present degenerate and two-color 2D spectra of the light-harvesting complex 1 of purple bacteria.

  5. Dosimetry verifications of the physical parameters of virtual wedge on a Siemens accelerator

    International Nuclear Information System (INIS)

    Zhong Heli; Li Xiaodong; Li Longxing

    2002-01-01

    Objective: To verify the wedge angle of virtual wedge and the relation between wedge factor and beam energy, field size, wedge angle and to study the difference in percent depth dose (PDD) of virtual wedge field, hard wedge field and open field. Methods: Using wedge angle and wedge factor of 15 degree, 30 degree, 45 degree and 60 degree virtual wedge of Siemens Mevatron 6 MV and Primus 8 MV, 18 MV X rays were measured by RFA-plus 3D water phantom and RK finger chamber the PDD of the virtual wedge field, hard wedge field and open field were measured by Kodak XV-2 verifying film and FDM-300 film dosimeter. These PDDs were normalized to Dmax then compared. Results: There was good conformation between virtual wedge measured by four point method and set value. The virtual wedge was almost equal to 1, with a maximal variation of 0.031 no matter what the value of beam energy, field size or wedge angle was. Generally, for certain energy and field size, the wedge factor of larger wedge angle was slightly larger than smaller wedge angle. For certain energy and wedge angle, the wedge factor of larger field was also a little larger than smaller field. The PDD of virtual wedge field was similar to that of open field. Conclusions: The four point method measurement for virtual wedge angle is good for daily QA. Radiotherapy of virtual wedge field is not only simpler than hard wedge field, but also spares the beam output. The PDD conferment between virtual field and open field simplifies radiation treatment planning and increases the accuracy of wedge field therapy

  6. Effects of Lateral Heel Wedges and Lateral Forefoot Wedge on the Knee Adduction Moment in Healthy Male Students

    Directory of Open Access Journals (Sweden)

    Fatemeh Shamsi

    2012-01-01

    Full Text Available Objective: Lateral wedged insoles have been designed to decrease the force applied on the medial knee compartment. The aim of this study was to assess the effects of laterally wedged insoles regarding to the placement of the wedge under the sole (under the heel or under the forefoot on the knee adduction moment and the ground reaction forces. Material & Methods: In this pretest-posttest study, three-dimensional gait analysis was performed on 20 healthy men between 18-30 years old. Knee adduction moment and ground reaction forces were compared among following three types of insoles: a flat insole, a 6˚ laterally inclined heel wedged insole and a 6˚ laterally- inclined forefoot wedged insole. Results: there was no difference between three conditions (flat insole (9.72±1.501, lateral heel wedge (9.866±2.141 and lateral forefoot wedge (9.952±1.986 in peak knee adduction moment (P>0.05. Ground reaction forces and spatiotemporal parameters of gait were not affected by any types of these insoles (P>0.05. Conclusion: Based on the current finding, placement of the lateral wedge under the sole, that is, under the heel or under the forefoot has no effect on the efficacy of these insoles on the adduction moment of the knee and ground reaction forces.

  7. Manual cross check of computed dose times for motorised wedged fields

    International Nuclear Information System (INIS)

    Porte, J.

    2001-01-01

    If a mass of tissue equivalent material is exposed in turn to wedged and open radiation fields of the same size, for equal times, it is incorrect to assume that the resultant isodose pattern will be effectively that of a wedge having half the angle of the wedged field. Computer programs have been written to address the problem of creating an intermediate wedge field, commonly known as a motorized wedge. The total exposure time is apportioned between the open and wedged fields, to produce a beam modification equivalent to that of a wedged field of a given wedge angle. (author)

  8. Slamming pressures on the bottom of a free-falling vertical wedge

    Science.gov (United States)

    Ikeda, C. M.; Judge, C. Q.

    2013-11-01

    High-speed planing boats are subjected to repeat impacts due to slamming, which can cause structural damage and injury to passengers. A first step in understanding and predicting the physics of a craft re-entering the water after becoming partially airborne is an experimental vertical drop test of a prismastic wedge (deadrise angle, β =20° beam, B = 300 mm; and length, L = 600 mm). The acrylic wedge was mounted to a rig allowing it to free-fall into a deep-water tank (5.2m × 5.2m × 4.2m deep) from heights 0 camera (1000 fps, resolution of 1920 × 1200 pixels) is mounted above the wedge model to record the wetted surface as the wedge descended below the free surface. The pressure measurements taken with both conventional surface pressure transducers and the pressure mapping system agree within 10% of the peak pressure values (0.7 bar, typical). Supported by the Office of Naval Research.

  9. A new algorithm for finite element simulation of wedge osteotomies in voxel models with application to the tibia

    Directory of Open Access Journals (Sweden)

    Thomas Pressel

    2010-01-01

    Full Text Available Thomas Pressel1, Markus D Schofer1, Jörg Meiforth2, Markus Lengsfeld1, Jan Schmitt11Department of Orthopaedics and Rheumatology, University Hospital Marburg, Marburg, Germany; 2St. Vincentius Kliniken, Klinik für Orthopädie, Karlsruhe, GermanyAbstract: Wedge osteotomies are used to correct bone deformities or change the forces acting on bones and joints in the human body. Finite element models can be employed to simulate the effect of such operations on the bone or adjacent joints. The automatic generation of voxel models derived from computed tomography data is a common procedure, but the major drawback of the method lies in irregular model surfaces. Therefore, the concept of hybrid models combining voxel and tetrahedron meshes was developed. We present an algorithm to simulate wedge osteotomies in voxel models by adding tetrahedron to brick elements. Applicability of the procedure was tested by performing a parametric study using a tibia model created from computed tomography scans taken in vivo applying individually calculated force conditions. The osteotomy angle largely affected maximum stresses: at 2.5 degrees valgus, the stresses at the medial and lateral tibial plateau were equivalent, while increasing valgus angles reduced medial stresses. The algorithm described here is an improvement of former mesh generation procedures and allows a better representation of the geometry at the osteotomy level. The algorithm can be used for all wedge osteotomies and is not limited to the tibia.Keywords: finite element/osteotomy/voxel/pre-operative planning, simulation, mesh algorithm

  10. Climate adaptation wedges: a case study of premium wine in the western United States

    Energy Technology Data Exchange (ETDEWEB)

    Diffenbaugh, Noah [Stanford University; White, Michael A [Utah State University (USU); Jones, Gregory V [Southern Oregon University, Ashland, OR; Ashfaq, Moetasim [ORNL

    2011-01-01

    Design and implementation of effective climate change adaptation activities requires quantitative assessment of the impacts that are likely to occur without adaptation, as well as the fraction of impact that can be avoided through each activity. Here we present a quantitative framework inspired by the greenhouse gas stabilization wedges of Pacala and Socolow. In our proposed framework, the damage avoided by each adaptation activity creates an 'adaptation wedge' relative to the loss that would occur without that adaptation activity. We use premium winegrape suitability in the western United States as an illustrative case study, focusing on the near-term period that covers the years 2000 39. We find that the projected warming over this period results in the loss of suitable winegrape area throughout much of California, including most counties in the high-value North Coast and Central Coast regions. However, in quantifying adaptation wedges for individual high-value counties, we find that a large adaptation wedge can be captured by increasing the severe heat tolerance, including elimination of the 50% loss projected by the end of the 2030 9 period in the North Coast region, and reduction of the projected loss in the Central Coast region from 30% to less than 15%. Increased severe heat tolerance can capture an even larger adaptation wedge in the Pacific Northwest, including conversion of a projected loss of more than 30% in the Columbia Valley region of Washington to a projected gain of more than 150%. We also find that warming projected over the near-term decades has the potential to alter the quality of winegrapes produced in the western US, and we discuss potential actions that could create adaptation wedges given these potential changes in quality. While the present effort represents an initial exploration of one aspect of one industry, the climate adaptation wedge framework could be used to quantitatively evaluate the opportunities and limits of climate

  11. Linking Serpentinite Geochemistry with Possible Alteration and Evolution of Supra-Subduction Wedge Mantle

    Science.gov (United States)

    Scambelluri, M.; Cannaò, E.; Agostini, S.; Gilio, M.

    2016-12-01

    Serpentinites are able to transport and release volatiles and fluid-mobile elements (FME) found in arc magmas. Constraining the trace element compositions of these rocks and of fluids released by de-serpentinization improves our knowledge of mass transfer from subduction zones to volcanic arcs, and of the role of slab and wedge mantle in this global process. Studies of high-pressure ultramafic rocks exhumed from plate interface settings reveal the fluid/rock interactions atop the slab and the processes that can affect the mantle wedge. Alpine eclogite-facies antigorite serpentinite (Voltri Massif) and fully de-serpentinized meta-peridotite (Cima di Gagnone) are enriched in sediment-derived As, Sb, U, Pb before peak dehydration. Their Sr, Pb and B isotopic compositions are reset during prograde (forearc) interaction with slab fluids. The eclogitic garnet and olivine from the Cima di Gagnone metaperidotite trap primary inclusions of the fluid released during breakdown of antigorite and chlorite. The inclusions display FME enrichments (high Cl, S; variable Cs, Rb, Ba, B, Pb, As, Sb) indicating element release from rocks to fluids during dehydration under subarc conditions. Our studies show that serpentinized mantle rocks from subduction zones sequester FME from slab fluids and convey these components and radiogenic isotopes into the mantle wedge upon dehydration. The geochemical processes revealed by such plate-interface rocks can apply to the supra-subduction mantle. Shallow element release from slabs to mantle wedge, downdrag of this altered mantle and its subsequent (subarc) dehydration transfers crust-derived FMEs to the arc magma sources without the need of concomitant subarc dehydration/melting of metasedimentary slab components. The slab signature detected in arc lavas can thus result from geochemical mixing of sediment, oceanic crust and ultramafic reservoirs into altered wedge-mantle rocks, rather than being attributed to multiple fluids.

  12. Nature of the Coastal Range Wedge Along the Rupture Area of the 2015, Illapel Chile Earthquake Mw 8.4

    Science.gov (United States)

    Farías, M.; Comte, D.; Roecker, S. W.; Brandon, M. T.

    2017-12-01

    Wedge theory is usually applied to the pro-side of active subduction margins, where fold-and-thrust belts related to frontal accretion develop, but rarely to the entire wedge, where the retro-side is also relevant. We present a new 3D body wave tomographic image that combines data from the Chile-Illapel Aftershock Experiment (CHILLAX) with previous temporary seismic networks, with the aim of illuminating the nature of the wedge of the continental margin above the seismogenic part of the subducting slab. The downdip extent of the coupled part, called the S-point in the wedge theory, corresponds to the place where upper plate completely decouples from the subducting slab. This point is characterized by a Vp/Vs contrast at about 60 km depth that extends upward-and-eastward in a west-dipping ramp-like geometry. This ramp emerges about 180 km from the trench, near the topographic break related to the front of the Andean retro-side. The Coastal wedge domain is characterized by a monotonous east-dipping homocline with the older rocks of this region along the coast. The offshore region, corresponding to the pro-side, exhibits normal faulting and a very small frontal accretionary complex. Normal faulting in this region is related to rapid uplift of marine terraces since ca. 2 Ma, suggesting strong basal accretion and thus high friction on the thrust. In fact, the epicentral region of the 2015 Illapel Earthquake coincides with the highest elevations along the coast, i.e., the region with the highest slope of the margin. In this region, the lack of a continental forearc basin suggests an overlapping between the Andean and Coastal wedges. The western edge of the Andean wedge is also part of the homocline about 10 km east of the topographic boundary between both wedges, suggesting that the Coastal wedge has been deforming a part of the retro-side of the Andean wedge during the Miocene. The east-ward tilting of the retro-side was acquired mainly before the late Miocene, since at

  13. Group sequential designs for stepped-wedge cluster randomised trials.

    Science.gov (United States)

    Grayling, Michael J; Wason, James Ms; Mander, Adrian P

    2017-10-01

    The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into

  14. Optical wedge method for spatial reconstruction of particle trajectories

    International Nuclear Information System (INIS)

    Asatiani, T.L.; Alchudzhyan, S.V.; Gazaryan, K.A.; Zograbyan, D.Sh.; Kozliner, L.I.; Krishchyan, V.M.; Martirosyan, G.S.; Ter-Antonyan, S.V.

    1978-01-01

    A technique of optical wedges allowing the full reconstruction of pictures of events in space is considered. The technique is used for the detection of particle tracks in optical wide-gap spark chambers by photographing in one projection. The optical wedges are refracting right-angle plastic prisms positioned between the camera and the spark chamber so that through them both ends of the track are photographed. A method for calibrating measurements is given, and an estimate made of the accuracy of the determination of the second projection with the help of the optical wedges

  15. PCL tibial avulsion with an associated medial meniscal tear in a child: a case report on diagnosis and management.

    LENUS (Irish Health Repository)

    2012-02-01

    Posterior cruciate ligament (PCL) injuries from tibial avulsions are rare in the paediatric setting. One would need a high index of suspicion as clinical examination may be difficult, especially in the early period. Magnetic resonance imaging is an excellent diagnostic modality for this condition and other associated injuries within the knee. We report a rare case in which the patient had a PCL avulsion off the tibial insertion site with an associated posterior horn medial meniscal tear off the posterior capsule. He was treated through open reduction and internal fixation of the avulsed fragment with suture repair of the meniscal tear. We emphasize the importance of diagnosing and managing associated intra-articular injuries when dealing with the rare condition of PCL tibial avulsion in the paediatric setting.

  16. Cartilaginous avulsion fracture of the tibial spine in a 5-year-old girl

    International Nuclear Information System (INIS)

    Kim, Jung Ryul; Song, Ji Hun; Lee, Ju Hong; Lee, Sang Yong; Yoo, Wan Hee

    2008-01-01

    Fractures of the tibial spine usually occur in children aged 8 to 14 years. Usually, radiographs will demonstrate a tibial spine fracture, with the degree of displacement. Tibial spine fractures in younger children have not been reported in the previously published literature. We report a tibial spine fracture that occurred in 5-year-old girl. The cartilaginous avulsion fracture of the tibial spine was not revealed by radiographs because it was limited to the cartilaginous portion of the proximal tibia. (orig.)

  17. Bilateral metachronous periosteal tibial amyloid tumors

    International Nuclear Information System (INIS)

    Murata, H.; Kusuzaki, Katsuyuki; Hashiguchi, S.; Ueda, Hidetaka; Hirasawa, Yasusuke

    2000-01-01

    Localized primary periosteal amyloid tumors are extremely rare. A case of bilateral tibial amyloid tumor is presented. A 62-year-old woman initially presented with a painful mass in the anterior aspect of the right leg. There was no evidence of underlying systemic disease, including chronic infection or malignancy. Based on the results of resistance with Congo red staining to treatment with potassium permanganate and positivity for kappa light chain, we classified this particular case as AL-type amyloidosis. The patient noticed a swelling in the opposite leg 2 years later. The second tumor was also an AL-type amyloidoma. Amyloid tumors are generally solitary. This is the first case of bilateral periosteal amyloid tumors of the AL-type occurring in the tibiae. (orig.)

  18. Computed tomography of tibial plateau fractures

    International Nuclear Information System (INIS)

    Rafii, M.; Firooznia, H.; Golimbu, C.; Bonamo, J.

    1984-01-01

    Twenty patients with tibial plateau fractures were studied by conventional tomography and computed tomography (CT) in order to determine the role and feasibility of CT in management of such patients. CT resulted in less discomfort to the patient and provided optimal visualization of the plateau defect and the split fragments. It proved more accurate than conventional tomography in assessing depressed and split fractures when they involved the anterior or posterior border of the plateau and in demonstrating the extent of fracture comminution. Split fragments with an oblique plane of fracture also were seen better by CT. The degree of fracture depression and separation as measured by the computerized technique was often more accurate than measurements obtained from conventional tomograms

  19. Physichal parameters for wedge filters used in radiotherapy

    International Nuclear Information System (INIS)

    Strunga, Emil

    1995-01-01

    Wedge filters using in radiotherapy up two important problems: attenuation of gamma rays introduced by the presence of wedge filters and spinning of isodoses curves plate. Depending of irradiation geometry, characterised by D w , - source filter distance, D c - source dose's estimate point distance, a - side of irradiation field; nature and size filter: α - wedge angle, μ - linear adsorption coefficient, ε - filter cover attenuation w - filter side, and nature of target volume characterised by μ' - linear absorption coefficient of medium has been estimated absorption factor of wedge filter (k w ) for two irradiation geometry: and spinning angle of isodose plate (Θ): 3) tg θ (μD w (μ'D c - 2 Calculated values has been compared with the experimental measured values, for a cobaltotherapy unit Rokus-M, and the result was that between the two series of dates it is a good concordance

  20. Numerical Study on Critical Wedge Angle of Cellular Detonation Reflections

    International Nuclear Information System (INIS)

    Gang, Wang; Kai-Xin, Liu; De-Liang, Zhang

    2010-01-01

    The critical wedge angle (CWA) for the transition from regular reflection (RR) to Mach reflection (MR) of a cellular detonation wave is studied numerically by an improved space-time conservation element and solution element method together with a two-step chemical reaction model. The accuracy of that numerical way is verified by simulating cellular detonation reflections at a 19.3° wedge. The planar and cellular detonation reflections over 45°–55° wedges are also simulated. When the cellular detonation wave is over a 50° wedge, numerical results show a new phenomenon that RR and MR occur alternately. The transition process between RR and MR is investigated with the local pressure contours. Numerical analysis shows that the cellular structure is the essential reason for the new phenomenon and the CWA of detonation reflection is not a certain angle but an angle range. (fundamental areas of phenomenology(including applications))

  1. Pilot Study: Foam Wedge Chin Support Static Tolerance Testing

    Science.gov (United States)

    2017-10-24

    AFRL-SA-WP-SR-2017-0026 Pilot Study: Foam Wedge Chin Support Static Tolerance Testing Austin M. Fischer, BS1; William W...COVERED (From – To) April – October 2017 4. TITLE AND SUBTITLE Pilot Study: Foam Wedge Chin Support Static Tolerance Testing 5a. CONTRACT NUMBER...PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) USAF School of Aerospace

  2. Ten-year survival and patient-reported outcomes of a medial unicompartmental knee arthroplasty incorporating an all-polyethylene tibial component.

    Science.gov (United States)

    Scott, Chloe E H; Wade, Frazer A; MacDonald, Deborah; Nutton, Richard W

    2018-05-01

    Biomechanical studies have suggested that proximal tibial strain is elevated in UKAs incorporating all-polyethylene tibial components with concern that this leads to premature failure. This study reports minimum 10-year outcomes for a UKA incorporating an all-polyethylene tibial component to determine whether these concerns were realised. 109 fixed bearing UKAs (97 patients, mean age 68 (range 48-87), 54/97 (56%) female) with all-polyethylene tibial components were followed up for ≥ 10 years with Oxford Knee Scores, Forgotten Joint Scores and Kaplan-Meier analysis. 106/109 implants were 7 mm, 3 were 9.5 mm. Ten-year survival was 85.5% (78.6-92.4 95% CI) with the end-point failure for any reason. Unexplained pain was the commonest mode of failure (6/17) followed by lateral compartment osteoarthritis (5/17) and tibial subsidence/loosening (4/17). Revision rate was highest at 2-5 years due to revisions for unexplained pain. Ten-year survival was worse in patients  30 (p = 0.017) and in those with postoperative increases in medial tibial sclerosis (p  30 was 2.9 (1.2-6.9 95% CI). In those with intact UKAs at 10 years, mean Oxford Knee Score was 34.8 ± 10.7, Forgotten Joint Score was 37.9 ± 26.7 and 96% were satisfied with their knee. The high rate of early failure between 2 and 5 years in this all-polyethylene tibial component UKA did not persist in the long term. Though medial proximal tibial metabolic changes appear to persist they are not necessarily symptomatic. BMI > 30 and age < 65 years were significant risk factors for revision.

  3. Comparison of Clinical Results and Injury Risk of Posterior Tibial Cortex Between Attune and Press Fit Condylar Sigma Knee Systems.

    Science.gov (United States)

    Song, Sang Jun; Park, Cheol Hee; Liang, Hu; Kang, Se Gu; Park, Jong Jun; Bae, Dae Kyung

    2018-02-01

    We compared clinical and radiographic results after total knee arthroplasty (TKA) using Attune and Press Fit Condylar Sigma, and investigated whether use of the current prosthesis increased injury risk to the tibial cortex in Asian patients. We also assessed whether a preoperative posterior tibial slope angle (PSA) is associated with the injury when using the current prosthesis. The 300 TKAs with Attune (group A) were compared to the 300 TKAs with Press Fit Condylar Sigma (group B). Demographics were not different, except follow-up periods (24.8 vs 33.3 months, P Universities Index and range of motion were compared. A minimum distance between tibial component stem and posterior tibial cortex (mDSC) was compared. The correlation between preoperative PSA and mDSC was analyzed in group A. The postoperative Western Ontario and McMaster Universities Index and range of motion of group A were better than those of group B (17.7 vs 18.8, P = .004; 131.4° vs 129.0°, P = .008). The mDSC was shorter in group A (6.3 vs 7.0 mm, P < .001), which made up a higher proportion of the high-risk group for posterior tibial cortical injury with an mDSC of <4 mm (20.0% vs 10.7%, P = .002). A negative correlation was found between the preoperative PSA and mDSC in group A (r = -0.205, P < .001). The TKA using the current prosthesis provided more satisfactory results than the TKA using the previous prosthesis. However, the injury risk to the posterior tibial cortex increased in the knees with a large PSA when using the current prosthesis for Asian patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Do Capacitively Coupled Electric Fields Accelerate Tibial Stress Fracture Healing

    National Research Council Canada - National Science Library

    Hoffman, Andrew

    2002-01-01

    A convenience sample based on availability of tibial stress fracture cases at local Sports Medicine Clinics will be selected over 2-3 years until forty subjects (20 male, 20 female) have been treated...

  5. Do Capacity Coupled Electric Fields Accelerate Tibial Stress Fracture Healing?

    National Research Council Canada - National Science Library

    Hoffman, Andrew

    2004-01-01

    A convenience sample based on availability of tibial stress fracture cases a% local Sports Medicine Clinics will be selected over 4 years until forty subjects (20 male, 20 female) have been treated...

  6. Do Capacitively Coupled Electric Fields Accelerate Tibial Stress Fracture Healing

    National Research Council Canada - National Science Library

    Hoffman, Andrew

    2003-01-01

    A convenience sample based on availability of tibial stress fracture cases at local Sports Medicine Clinics will be selected over 2-3 years until forty subjects (20 male, 20 female) have been treated...

  7. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures.

    Science.gov (United States)

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

    Statically locked, reamed intramedullary nailing remains the standard treatment for displaced tibial shaft fractures. Establishing an appropriate starting point is a crucial part of the surgical procedure. Recently, suprapatellar nailing in the semi-extended position has been suggested as a safe and effective surgical technique. Numerous reduction techiques are available to achieve an anatomic fracture alignment and the treating surgeon should be familiar with these maneuvers. Open reduction techniques should be considered if anatomic fracture alignment cannot be achieved by closed means. Favorable union rates above 90 % can be achieved by both reamed and unreamed intramedullary nailing. Despite favorable union rates, patients continue to have functional long-term impairments. In particular, anterior knee pain remains a common complaint following intramedullary tibial nailing. Malrotation remains a commonly reported complication after tibial nailing. The effect of postoperative tibial malalignment on the clinical and radiographic outcome requires further investigation.

  8. SU-E-T-362: Enhanced Dynamic Wedge Output Factors for Varian 2300CD and the Case for a Reference Database

    International Nuclear Information System (INIS)

    Njeh, C

    2015-01-01

    Purpose: Dose inhomogeneity in treatment planning can be compensated using physical wedges. Enhanced dynamic wedges (EDW) were introduced by Varian to overcome some of the short comings of physical wedges. The objectives of this study were to measure EDW output factors for 6 MV and 20 MV photon energies for a Varian 2300CD. Secondly to review the literature in terms of published enhanced dynamic wedge output factors (EDWOF) for different Varian models and thereby adding credence to the case of the validity of reference databases. Methods: The enhanced dynamic wedge output factors were measured for the Varian 2300CD for both 6 MV and 20 MV photon energies. Twelve papers with published EDWOF for different Varian Linac models were found in the literature. Results: The EDWOF for 6 MV varied from 0.980 for a 5×5 cm 10 degree wedge to 0.424 for 20×20 cm 60 degree wedge. Similarly for 20 MV, the EDWOF varied from 0.986 for 5×5 cm 10 degree wedge to 0.529 for 20×20 cm 60 degree wedge. EDWOF are highly dependent on field size. Comparing our results with the published mean, we found an excellent agreement for 6 MV EDWOF with the percentage differences ranging from 0.01% to 0.57% with a mean of 0.03%. The coefficient of variation of published EDWOF ranged from 0.17% to 0.85% and 0.1% to 0.9% for the for 6 MV and 18MV photon energies respectively. This paper provides the first published EDWOF for 20 MV photon energy. In addition, we have provided the first compendium of EDWOFs for different Varian linac models. Conclusion: The consistency of EDWOF across models and institution provide further support that, a standard data set of basic photon and electron dosimetry could be established, as a guide for future commissioning, beam modeling and quality assurance purposes

  9. Effects of laterally wedged insoles on symptoms and disease progression in medial knee osteoarthritis: a protocol for a randomised, double-blind, placebo controlled trial

    Directory of Open Access Journals (Sweden)

    Osborne Richard

    2007-09-01

    Full Text Available Abstract Background Whilst laterally wedged insoles, worn inside the shoes, are advocated as a simple, inexpensive, non-toxic self-administered intervention for knee osteoarthritis (OA, there is currently limited evidence to support their use. The aim of this randomised, double-blind controlled trial is to determine whether laterally wedges insoles lead to greater improvements in knee pain, physical function and health-related quality of life, and slower structural disease progression as well as being more cost-effective, than control flat insoles in people with medial knee OA. Methods/Design Two hundred participants with painful radiographic medial knee OA and varus malalignment will be recruited from the community and randomly allocated to lateral wedge or control insole groups using concealed allocation. Participants will be blinded as to which insole is considered therapeutic. Blinded follow up assessment will be conducted at 12 months after randomisation. The outcome measures are valid and reliable measures recommended for OA clinical trials. Questionnaires will assess changes in pain, physical function and health-related quality-of-life. Magnetic resonance imaging will measure changes in tibial cartilage volume. To evaluate cost-effectiveness, participants will record the use of all health-related treatments in a log-book returned to the assessor on a monthly basis. To test the effect of the intervention using an intention-to-treat analysis, linear regression modelling will be applied adjusting for baseline outcome values and other demographic characteristics. Discussion Results from this trial will contribute to the evidence regarding the effectiveness of laterally wedged insoles for the management of medial knee OA. Trial registration ACTR12605000503628; NCT00415259.

  10. Displaced tibial shaft fractures treated with ASIF compression internal fixation

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Larsen, T K; Petersen, O C

    1990-01-01

    Fifty-one tibial shaft fractures treated by ASIF compression osteosynthesis were seen at follow-up at a median time of 46 weeks after injury. Twenty-four were open fractures and the patients received prophylactic antibiotics. The median stay in hospital was 15 days for open fractures and 6 days f...... for closed fractures. There were complications in 26 cases, with deep infection in 9 cases. At present we cannot advocate the use of ASIF compression osteosynthesis for displaced tibial fractures....

  11. Physeal growth arrest after tibial lengthening in achondroplasia

    Science.gov (United States)

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

  12. A PROSPECTIVE STUDY OF DISTAL TIBIAL FRACTURES BY MIPO (LCP)

    OpenAIRE

    Chandra Sekharam Naidu; Ch.Murali Krishna; Sankara Rao; Dharma Rao; Ashok Kumar

    2015-01-01

    INTRODUCTION: D istal tibial fractures represent a significant challenge to most of the surgeons even today. They constitute 1 - 10% of all lower extremity fractures . 1 The difficulty in treating the fractures of distal tibial end is exemplif ied by orthopedists, who in the first half of twentieth century, believed these injuries were so severe and fraught with so many complications, that these fractures wer...

  13. The medial tibial stress syndrome. A cause of shin splints.

    Science.gov (United States)

    Mubarak, S J; Gould, R N; Lee, Y F; Schmidt, D A; Hargens, A R

    1982-01-01

    The medial tibial stress syndrome is a symptom complex seen in athletes who complain of exercise-induced pain along the distal posterior-medial aspect of the tibia. Intramuscular pressures within the posterior compartments of the leg were measured in 12 patients with this disorder. These pressures were not elevated and therefore this syndrome is a not a compartment syndrome. Available information suggests that the medial tibial stress syndrome most likely represents a periostitis at this location of the leg.

  14. Sandbox Simulations of the Evolution of a Subduction Wedge following Subduction Initiation

    Science.gov (United States)

    Brandon, M. T.; Ma, K. F.; DeWolf, W.

    2012-12-01

    Subduction wedges at accreting subduction zones are bounded by a landward dipping pro-shear zone (= subduction thrust) and a seaward-dipping retro-shear zone in the overriding plate. For the Cascadia subduction zone, the surface trace of the retro-shear zone corresponds to the east side of the Coast Ranges of Oregon and Washington and the Insular Mountains of Vancouver Island. This coastal high or forearc high shows clear evidence of long-term uplift and erosion along its entire length, indicating that it is an active part of the Cascadia subduction wedge. The question addressed here is what controls the location of the retro-shear zone? In the popular double-sided wedge model of Willet et al (Geology 1993), the retro-shear zone remains pinned to the S point, which is interpreted to represent where the upper-plate Moho intersects the subduction zone. For this interpretation, the relatively strong mantle is considered to operate as a flat backstop. That model, however. is somewhat artificial in that the two plates collide in a symmetric fashion with equal crustal thicknesses on both sides. Using sandbox experiments, we explore a more realistic configuration where the upper and lower plate are separated by a gentle dipping (10 degree) pro-shear zone, to simulate the initial asymmetric geometry of the subduction thrust immediately after initiation of subduction. The entire lithosphere must fail along some plane for subduction to begin and this failure plane must dip in the direction of subduction. Thus, the initial geometry of the overriding plate is better approximated as a tapered wedge than as a layer of uniform thickness, as represented in the Willett et al models. We demonstrate this model using time-lapse movies of a sand wedge above a mylar subducting plate. We use particle image velocimetry (PIV) to show the evolution of strain and structure within the overriding plate. Material accreted to the tapered end of the overriding plate drives deformation and causes

  15. [Custom-designed 3D tibial augmentation for knee replacement].

    Science.gov (United States)

    Jirman, R; Vavrík, P; Horák, Z

    2009-02-01

    Reconstruction with the use of custom-made implants aims at optimal replacement of lost or damaged bone structures and restoration of their funkction. In this study the development and construction of a custom-made implant and the operative technique used for the treatment of an extensive tibial defect are described. The patient was a 65-year-old man treated for over 20 years for psoriatic arthritis and severe instability of the right knee, particularly in the frontal plane, with a worsening varus deformity. The radiogram showed an extensive destruction of the medial tibial condyle that also deeply involved the lateral condyle. The extent of defect made it impossible to use any commercial tibial augmentation. The geometry of the custom-designed implant for the medial tibial condyle was constructed on the basis of a 3D defect model and the shape of the medial tibial condyle of the collateral knee seen on CT scans. After its correct shape was verified on a plastic model, its coordinates were set in the software of a machine tool, and a titanium augmentation otherwise compatible with a standard knee replacement was produced.The use of such a custom implant to complete standard total knee arthroplasty has so far been demanding in terms of organisation and manufacture. Its production in the future could be facilitated by substituting titanium for plastic material such as poly-ether-ether-ketone (PEEK). Key words: custom-made implant, tibial augmentation, knee prosthesis.

  16. Gender differences in passive knee biomechanical properties in tibial rotation.

    Science.gov (United States)

    Park, Hyung-Soon; Wilson, Nicole A; Zhang, Li-Qun

    2008-07-01

    The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender-specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60 degrees of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction.

  17. Precision of tibial cartilage morphometry with a coronal water-excitation MR sequence

    Energy Technology Data Exchange (ETDEWEB)

    Hyhlik-Duerr, A. [Musculoskeletal Research Group, Institute of Anatomy, Ludwig-Maximilians-Universitaet, Muenchen (Germany); Klinik fuer Orthopaedie und Sportorthopaedie der Technischen Universitaet, Muenchen (Germany); Faber, S.; Reiser, M. [Klinik fuer Orthopaedie und Sportorthopaedie der Technischen Universitaet, Muenchen (Germany); Burgkart, R. [Institut fuer Medizinische Informatik und Systemforschung (MEDIS), GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg, Oberschleissheim (Germany); Stammberger, T.; Englmeier, K.H. [Institut fuer Medizinische Informationsverarbeitung, Biometrie und Epidemiologie, Klinikum Grosshadern, Marchioninistrasse 15, D-81377 Munich (Germany); Maag, K.P. [Institut fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Universitaet, Muenchen (Germany); Eckstein, F. [Musculoskeletal Research Group, Institute of Anatomy, Ludwig-Maximilians-Universitaet, Muenchen (Germany)

    2000-02-01

    The aim of this study was to analyze the precision of tibial cartilage morphometry, by using a fast, coronal water-excitation sequence with high spatial resolution, to compare the reproducibility of 3D thickness vs volume estimates, and to test the technique in patients with severe osteoarthritis. The tibiae of 8 healthy volunteers and 3 patients selected for total knee arthroplasty were imaged repeatedly with a water-excitation sequence (image time 6 h 19 min, resolution 1.2 x 0.31 x 0.31 mm{sup 3}), with the knee being repositioned between each replicate acquisition. After 3D reconstruction, the cartilage volume, the mean, and the maximal tibial cartilage thickness were determined by 3D Euclidean distance transformation. In the volunteers, the precision of the volume measurements was 2.3 % (CV%) in the medial and 2.6 % in the lateral tibia. The reproducibility of the mean cartilage thickness was similar (2.6 and 2.5 %, respectively), and that of the maximal thickness lower (6.5 and 4.4 %). The patients showed a considerable reduction in volume and thickness, the precision being comparable with that in the volunteers. We find that, using a new imaging protocol and computational algorithm, it is possible to determine tibial cartilage morphometry with high precision in healthy individuals as well as in patients with osteoarthritis. (orig.)

  18. Comparison of dosimetric methods for virtual wedge analysis

    International Nuclear Information System (INIS)

    Bailey, M.; Nelson, V.; Collins, O.; West, M.; Holloway, L.; Rajapaske, S.; Arts, J.; Varas, J.; Cho, G.; Hill, R.

    2004-01-01

    Full text: The Siemens Virtual Wedge (Concord, USA) creates wedged beam profile by moving a single collimator jaw across the specified field size whilst varying the dose rate and jaw speed for use in the delivery of radiotherapy treatments. The measurement of the dosimetric characteristics of the Siemens Virtual Wedge poses significant challenges to medical physicists. This study investigates several different methods for measuring and analysing the virtual wedge for data collection for treatment planning systems and ongoing quality assurance. The beam profiles of the Virtual Wedge (VW) were compared using several different dosimetric methods. Open field profiles were measured with Kodak X-Omat V (Rochester, NY, USA) radiographic film and compared with measurements made using the Sun Nuclear Profiler with a Motorized Drive Assembly (MDA) (Melbourne, FL, USA) and the Scanditronix Wellhofer CC13 ionisation chamber and 24 ion Chamber Array (CA24) (Schwarzenbruck, Germany). The resolution of each dosimetric method for open field profiles was determined. The Virtual Wedge profiles were measured with radiographic film the Profiler and the Scanditronix Wellhofer CA 24 ion Chamber Array at 5 different depths. The ease of setup, time taken, analysis and accuracy of measurement were all evaluated to determine the method that would be both appropriate and practical for routine quality assurance of the Virtual Wedge. The open field profiles agreed within ±2% or 2mm for all dosimetric methods. The accuracy of the Profiler and CA24 are limited to half of the step size selected for each of these detectors. For the VW measurements a step size of 2mm was selected for the Profiler and the CA24. The VW profiles for all dosimetric methods agreed within ±2% or 2mm for the main wedged section of the profile. The toe and heel ends of the wedges showed the significant discrepancies dependent upon the dosimetry method used, up to 7% for the toe end with the CA24. The dosimetry of the

  19. Seismological evidence for a sub-volcanic arc mantle wedge beneath the Denali volcanic gap, Alaska

    Science.gov (United States)

    McNamara, D.E.; Pasyanos, M.E.

    2002-01-01

    Arc volcanism in Alaska is strongly correlated with the 100 km depth contour of the western Aluetian Wadati-Benioff zone. Above the eastern portion of the Wadati-Benioff zone however, there is a distinct lack of volcanism (the Denali volcanic gap). We observe high Poisson's ratio values (0.29-0.33) over the entire length of the Alaskan subduction zone mantle wedge based on regional variations of Pn and Sn velocities. High Poisson's ratios at this depth (40-70 km), adjacent to the subducting slab, are attributed to melting of mantle-wedge peridotites, caused by fluids liberated from the subducting oceanic crust and sediments. Observations of high values of Poisson's ratio, beneath the Denali volcanic gap suggest that the mantle wedge contains melted material that is unable to reach the surface. We suggest that its inability to migrate through the overlying crust is due to increased compression in the crust at the northern apex of the curved Denali fault.

  20. Fabrication of customizable wedged multilayer Laue lenses by adding a stress layer

    International Nuclear Information System (INIS)

    Niese, Sven; Krüger, Peter; Kubec, Adam; Laas, Roman; Gawlitza, Peter; Melzer, Kathleen; Braun, Stefan; Zschech, Ehrenfried

    2014-01-01

    Diffractive optics for hard X-rays feature superior properties in terms of resolution and efficiency, if volume diffraction effects are exploited all-over the aperture. For multilayer Laue lenses, preferably a wedged geometry is required to obtain this effect. We present an approach utilizing an additional stress layer to realize the necessary geometrical modifications where each lens can be customized to a selected photon energy independently of the given multilayer deposition. The quality of the deposition of the stress layer is evaluated using a laboratory X-ray microscope prior to its application at synchrotron radiation facilities with a special approach to measure the relative layer tilt at high spatial resolution. - Highlights: • Wedged multilayer Laue lenses were fabricated using an additional stress layer. • Each lens can be customized to any photon energy independently of the multilayer. • The relative layer tilt is measured using laboratory X-ray microscopy

  1. The evolving energy budget of accretionary wedges

    Science.gov (United States)

    McBeck, Jessica; Cooke, Michele; Maillot, Bertrand; Souloumiac, Pauline

    2017-04-01

    The energy budget of evolving accretionary systems reveals how deformational processes partition energy as faults slip, topography uplifts, and layer-parallel shortening produces distributed off-fault deformation. The energy budget provides a quantitative framework for evaluating the energetic contribution or consumption of diverse deformation mechanisms. We investigate energy partitioning in evolving accretionary prisms by synthesizing data from physical sand accretion experiments and numerical accretion simulations. We incorporate incremental strain fields and cumulative force measurements from two suites of experiments to design numerical simulations that represent accretionary wedges with stronger and weaker detachment faults. One suite of the physical experiments includes a basal glass bead layer and the other does not. Two physical experiments within each suite implement different boundary conditions (stable base versus moving base configuration). Synthesizing observations from the differing base configurations reduces the influence of sidewall friction because the force vector produced by sidewall friction points in opposite directions depending on whether the base is fixed or moving. With the numerical simulations, we calculate the energy budget at two stages of accretion: at the maximum force preceding the development of the first thrust pair, and at the minimum force following the development of the pair. To identify the appropriate combination of material and fault properties to apply in the simulations, we systematically vary the Young's modulus and the fault static and dynamic friction coefficients in numerical accretion simulations, and identify the set of parameters that minimizes the misfit between the normal force measured on the physical backwall and the numerically simulated force. Following this derivation of the appropriate material and fault properties, we calculate the components of the work budget in the numerical simulations and in the

  2. Casimir effect for a semitransparent wedge and an annular piston

    International Nuclear Information System (INIS)

    Milton, Kimball A.; Wagner, Jef; Kirsten, Klaus

    2009-01-01

    We consider the Casimir energy due to a massless scalar field in a geometry of an infinite wedge closed by a Dirichlet circular cylinder, where the wedge is formed by δ-function potentials, so-called semitransparent boundaries. A finite expression for the Casimir energy corresponding to the arc and the presence of both semitransparent potentials is obtained, from which the torque on the sidewalls can be derived. The most interesting part of the calculation is the nontrivial nature of the angular mode functions. Numerical results are obtained which are closely analogous to those recently found for a magnetodielectric wedge, with the same speed of light on both sides of the wedge boundaries. Alternative methods are developed for annular regions with radial semitransparent potentials, based on reduced Green's functions for the angular dependence, which allows calculations using the multiple-scattering formalism. Numerical results corresponding to the torque on the radial plates are likewise computed, which generalize those for the wedge geometry. Generally useful formulas for calculating Casimir energies in separable geometries are derived.

  3. Treatment of large posttraumatic tibial bone defects using the Ilizarov method: a subjective outcome assessment.

    Science.gov (United States)

    Krappinger, Dietmar; Irenberger, Alexander; Zegg, Michael; Huber, Burkhart

    2013-06-01

    The treatment of large posttraumatic tibial bone defects using the Ilizarov method was shown to be successful in several studies. These studies, however, typically focus on the radiological and functional outcome using objective parameters only. The aim of the present study was therefore to assess the objective and subjective outcome of a consecutive series of patients with large posttraumatic tibial bone defects using the Ilizarov method. Additionally, it was our goal to assess the physical and mental stress for the patients and their relatives during the long treatment period and the general health status at final follow-up. A consecutive series of 15 patients with posttraumatic tibial bone defects of >30 mm after sustaining open tibial fractures and failure of internal fixation was included. The objective outcome was assessed at final follow-up using Paley's criteria. For the assessment of the subjective outcome, all patients were asked to evaluate their satisfaction with the function of the lower leg, the cosmetic appearance and overall outcome as well. The physical and mental stress of the treatment for the patients and the nearest relative of patients were assessed at the time of frame removal using a custom-made questionnaire. The SF-36 was used to evaluate the general health status at final follow-up. Solid bone union with stable soft tissue coverage and eradication of infection was achieved in all patients despite a high complication rate. The functional outcome at final follow-up was excellent or good in all patients. The patients' satisfaction with the overall outcome and the function of the lower extremity was high as well. The fear of amputation and complications was the major subjective burden for both the patients and their relatives. The long external fixation time is another relevant issue. The Ilizarov method is a safe option for the treatment of large posttraumatic tibial bone defects after failure of internal fixation despite the high

  4. Preserving the PCL during the tibial cut in total knee arthroplasty.

    Science.gov (United States)

    Cinotti, G; Sessa, P; Amato, M; Ripani, F R; Giannicola, G

    2017-08-01

    Previous studies have shown that the PCL insertion may be damaged during the tibial cut performed in total knee arthroplasty. We investigated the maximum thickness of a tibial cut that preserves the PCL insertion and to what extent the posterior slope of the tibial cut and that of the patient's tibial plateaus affect the outcome. MR images of 83 knees were analysed. The maximum thickness of a tibial cut that preserves the PCL using a posterior slope of 0°, 3°, 5° and parallel to the patient's slope of the tibial plateau, was evaluated. Correlations between the results and the degrees of the posterior slope of the patient's tibial plateaus were also investigated. The maximum thickness of a tibial cut that preserves the entire PCL insertion was, on average, 5.5, 4.7, 4.2 and 3.1 mm when a posterior slope of 0°, 3°, 5° and parallel to the patients' tibial plateaus was used, respectively. When the 25th percentile was considered, the maximum thickness of a tibial cut that preserved the PCL was 4 and 3 mm with a tibial cut of 0° and 5° of posterior slope, respectively. The maximum thickness of a tibial cut that preserved the PCL was significantly greater in patients with a sagittal slope of the tibial plateaus more than 8° than in those with a sagittal slope less than 8°. In cruciate retaining implants, the PCL insertion may be spared in the majority of patients by performing a tibial cut of 4 mm, or even less when a posterior slope of 3°-5° is used. The clinical relevance of our study is that the execution of a conservative tibial cut, followed by a second tibial resection to achieve the thickness required for the tibial component to be implanted, may be an alternative technique to spare the PCL in CR TKA. II.

  5. Outcome of limb reconstruction system in open tibial diaphyseal fractures

    Directory of Open Access Journals (Sweden)

    Anand Ajmera

    2015-01-01

    Full Text Available Background: Management of open tibial diaphyseal fractures with bone loss is a matter of debate. The treatment options range from external fixators, nailing, ring fixators or grafting with or without plastic reconstruction. All the procedures have their own set of complications, like acute docking problems, shortening, difficulty in soft tissue management, chronic infection, increased morbidity, multiple surgeries, longer hospital stay, mal union, nonunion and higher patient dissatisfaction. We evaluated the outcome of the limb reconstruction system (LRS in the treatment of open fractures of tibial diaphysis with bone loss as a definative mode of treatment to achieve union, as well as limb lengthening, simultaneously. Materials and Methods: Thirty open fractures of tibial diaphysis with bone loss of at least 4 cm or more with a mean age 32.5 years were treated by using the LRS after debridement. Distraction osteogenesis at rate of 1 mm/day was done away from the fracture site to maintain the limb length. On the approximation of fracture ends, the dynamized LRS was left for further 15-20 weeks and patient was mobilized with weight bearing to achieve union. Functional assessment was done by Association for the Study and Application of the Methods of Illizarov (ASAMI criteria. Results: Mean followup period was 15 months. The mean bone loss was 5.5 cm (range 4-9 cm. The mean duration of bone transport was 13 weeks (range 8-30 weeks with a mean time for LRS in place was 44 weeks (range 24-51 weeks. The mean implant index was 56.4 days/cm. Mean union time was 52 weeks (range 31-60 weeks with mean union index of 74.5 days/cm. Bony results as per the ASAMI scoring were excellent in 76% (19/25, good in 12% (3/25 and fair in 4% (1/25 with union in all except 2 patients, which showed poor results (8% with only 2 patients having leg length discrepancy more than 2.5 cm. Functional results were excellent in 84% (21/25, good in 8% (2/25, fair in 8% (2/25. Pin

  6. Outcome of limb reconstruction system in open tibial diaphyseal fractures.

    Science.gov (United States)

    Ajmera, Anand; Verma, Ankit; Agrawal, Mukul; Jain, Saurabh; Mukherjee, Arunangshu

    2015-01-01

    Management of open tibial diaphyseal fractures with bone loss is a matter of debate. The treatment options range from external fixators, nailing, ring fixators or grafting with or without plastic reconstruction. All the procedures have their own set of complications, like acute docking problems, shortening, difficulty in soft tissue management, chronic infection, increased morbidity, multiple surgeries, longer hospital stay, mal union, nonunion and higher patient dissatisfaction. We evaluated the outcome of the limb reconstruction system (LRS) in the treatment of open fractures of tibial diaphysis with bone loss as a definative mode of treatment to achieve union, as well as limb lengthening, simultaneously. Thirty open fractures of tibial diaphysis with bone loss of at least 4 cm or more with a mean age 32.5 years were treated by using the LRS after debridement. Distraction osteogenesis at rate of 1 mm/day was done away from the fracture site to maintain the limb length. On the approximation of fracture ends, the dynamized LRS was left for further 15-20 weeks and patient was mobilized with weight bearing to achieve union. Functional assessment was done by Association for the Study and Application of the Methods of Illizarov (ASAMI) criteria. Mean followup period was 15 months. The mean bone loss was 5.5 cm (range 4-9 cm). The mean duration of bone transport was 13 weeks (range 8-30 weeks) with a mean time for LRS in place was 44 weeks (range 24-51 weeks). The mean implant index was 56.4 days/cm. Mean union time was 52 weeks (range 31-60 weeks) with mean union index of 74.5 days/cm. Bony results as per the ASAMI scoring were excellent in 76% (19/25), good in 12% (3/25) and fair in 4% (1/25) with union in all except 2 patients, which showed poor results (8%) with only 2 patients having leg length discrepancy more than 2.5 cm. Functional results were excellent in 84% (21/25), good in 8% (2/25), fair in 8% (2/25). Pin tract infection was seen in 5 cases, out of which 4

  7. The effect of proximal tibial slope on dynamic stability testing of the posterior cruciate ligament- and posterolateral corner-deficient knee.

    Science.gov (United States)

    Petrigliano, Frank A; Suero, Eduardo M; Voos, James E; Pearle, Andrew D; Allen, Answorth A

    2012-06-01

    Proximal tibial slope has been shown to influence anteroposterior translation and tibial resting point in the posterior cruciate ligament (PCL)-deficient knee. The effect of proximal tibial slope on rotational stability of the knee is unknown. Change in proximal tibial slope produced via osteotomy can influence both static translation and dynamic rotational kinematics in the PCL/posterolateral corner (PLC)-deficient knee. Controlled laboratory study. Posterior drawer, dial, and mechanized reverse pivot-shift (RPS) tests were performed on hip-to-toe specimens and translation of the lateral and medial compartments measured utilizing navigation (n = 10). The PCL and structures of the PLC were then sectioned. Stability testing was repeated, and compartmental translation was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5° or -5° of tibial slope variation, after which stability testing was repeated (n = 10). Analysis was performed using 1-way analysis of variance (ANOVA; α = .05). Combined sectioning of the PCL and PLC structures resulted in a 10.5-mm increase in the posterior drawer, 15.5-mm increase in the dial test at 30°, 14.5-mm increase in the dial test at 90°, and 17.9-mm increase in the RPS (vs intact; P slope (high tibial osteotomy [HTO] +5°) in the PCL/PLC-deficient knee reduced medial compartment translation by 3.3 mm during posterior drawer (vs deficient; P slope (HTO -5°) caused a 4.8-mm increase in medial compartment translation (vs deficient state; P slope diminished static posterior instability of the PCL/PLC-deficient knee as measured by the posterior drawer test but had little effect on rotational or dynamic multiplanar stability as assessed by the dial and RPS tests, respectively. Conversely, decreasing posterior slope resulted in increased posterior instability and a significant increase in the magnitude of the RPS. These results suggest that increasing posterior tibial slope may improve

  8. RANS Analyses of Turbofan Nozzles with Internal Wedge Deflectors for Noise Reduction

    Science.gov (United States)

    DeBonis, James R.

    2009-01-01

    Computational fluid dynamics (CFD) was used to evaluate the flow field and thrust performance of a promising concept for reducing the noise at take-off of dual-stream turbofan nozzles. The concept, offset stream technology, reduces the jet noise observed on the ground by diverting (offsetting) a portion of the fan flow below the core flow, thickening and lengthening this layer between the high-velocity core flow and the ground observers. In this study a wedge placed in the internal fan stream is used as the diverter. Wind, a Reynolds averaged Navier-Stokes (RANS) code, was used to analyze the flow field of the exhaust plume and to calculate nozzle performance. Results showed that the wedge diverts all of the fan flow to the lower side of the nozzle, and the turbulent kinetic energy on the observer side of the nozzle is reduced. This reduction in turbulent kinetic energy should correspond to a reduction in noise. However, because all of the fan flow is diverted, the upper portion of the core flow is exposed to the freestream, and the turbulent kinetic energy on the upper side of the nozzle is increased, creating an unintended noise source. The blockage due to the wedge reduces the fan mass flow proportional to its blockage, and the overall thrust is consequently reduced. The CFD predictions are in very good agreement with experimental flow field data, demonstrating that RANS CFD can accurately predict the velocity and turbulent kinetic energy fields. While this initial design of a large scale wedge nozzle did not meet noise reduction or thrust goals, this study identified areas for improvement and demonstrated that RANS CFD can be used to improve the concept.

  9. Fluxes and burial of particulate organic carbon along the Adriatic mud-wedge (Mediterranean Sea)

    Science.gov (United States)

    Tesi, T.; Langone, L.; Giani, M.; Ravaioli, M.; Miserocchi, S.

    2012-04-01

    Clinoform-shaped deposits are ubiquitous sedimentological bodies of modern continental margins, including both carbonate and silicoclastic platforms. They formed after the attainment of the modern sea level high-stand (mid-late Holocene) when river outlets and shoreline migrated landward. As clinoform-shape deposits are essential building blocks of the infill of sedimentary basins, they are sites of intense organic carbon (OC) deposition and account for a significant fraction of OC burial in the ocean during interglacial periods. In this study, we focused on sigmoid clinoforms that are generally associated with low-energy environments. In particular, we characterized the modern accumulation and burial of OC along the late-Holocene sigmoid in the Western Adriatic Sea (Mediterranean Sea). This sedimentary body consists of a mud wedge recognizable on seismic profiles as a progradational unit lying on top the maximum flooding surface that marks the time of maximum landward shift of the shoreline attained around 5.5 kyr cal BP. In the last two decades, several projects have investigated sediment dynamics and organic geochemistry along the Adriatic mud wedge (e.g., PRISMA, EURODELTA, EuroSTRATAFORM, PASTA, CIPE, VECTOR). All these studies increased our understanding of strata formation and organic matter cycling in this epicontinental margin. The overarching goal of this study was to combine the results gained during these projects with newly acquired data to assess fluxes to seabed and burial efficiency of organic carbon along the uppermost strata of the Adriatic mud-wedge. Our study benefited of an extensive number of radionuclide-based (Pb-210, and Cs-137) sediment accumulation rates and numerous biogeochemical data of surface sediments and sediment cores (organic carbon, total nitrogen, radiocarbon measurements, carbon stable isotopes, and biomarkers). In addition, because the accumulation of river-borne sediment may or may not be linked to a specific source, another

  10. Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence

    Science.gov (United States)

    Hwang, Jin Hwan; Jang, Dongmin; Kim, Yong Hoon

    2017-12-01

    Advection, straining, and vertical mixing play primary roles in the process of estuarine stratification. Estuaries can be classified as salt-wedge, partially-mixed or well-mixed depending on the vertical density structure determined by the balancing of advection, mixing and straining. In particular, straining plays a major role in the stratification of the estuarine water body along the estuarine channel. Also, the behavior of a salt wedge with a halocline shape in a stratified channel can be controlled by the competition between straining and mixing induced by buoyancy from the riverine source and tidal forcing. The present study uses Finite Volume Coastal Ocean Model (FVCOM) to show that straining and vertical mixing play major roles in controlling along-channel flow and stratification structures in the Seomjin river estuary (SRE) under idealized conditions. The Potential Energy Anomaly (PEA) dynamic equation quantifies the governing processes thereby enabling the determination of the stratification type. By comparing terms in the equation, we examined how the relative strengths of straining and mixing alter the stratification types in the SRE due to changes in river discharge and the depth resulting from dredging activities. SRE under idealized tidal forcing tends to be partially-mixed based on an analysis of the balance between terms and the vertical structure of salinity, and the morphological and hydrological change in SRE results in the shift of stratification type. While the depth affects the mixing, the freshwater discharge mainly controls the straining, and the balance between mixing and straining determines the final state of the stratification in an estuarine channel. As a result, the development and location of a salt wedge along the channel in a partially mixed and highly stratified condition is also determined by the ratio of straining to mixing. Finally, our findings confirm that the contributions of mixing and straining can be assessed by using the

  11. Perturbation solutions for flow through symmetrical hoppers with inserts and asymmetrical wedge hoppers

    Science.gov (United States)

    Cox, G. M.; Mccue, S. W.; Thamwattana, N.; Hill, J. M.

    Under certain circumstances, an industrial hopper which operates under the "funnel-flow" regime can be converted to the "mass-flow" regime with the addition of a flow-corrective insert. This paper is concerned with calculating granular flow patterns near the outlet of hoppers that incorporate a particular type of insert, the cone-in-cone insert. The flow is considered to be quasi-static, and governed by the Coulomb-Mohr yield condition together with the non-dilatant double-shearing theory. In two-dimensions, the hoppers are wedge-shaped, and as such the formulation for the wedge-in-wedge hopper also includes the case of asymmetrical hoppers. A perturbation approach, valid for high angles of internal friction, is used for both two-dimensional and axially symmetric flows, with analytic results possible for both leading order and correction terms. This perturbation scheme is compared with numerical solutions to the governing equations, and is shown to work very well for angles of internal friction in excess of 45°.

  12. Modeling and Stability Analysis of Wedge Clutch System

    Directory of Open Access Journals (Sweden)

    Jian Yao

    2014-01-01

    Full Text Available A wedge clutch with unique features of self-reinforcement and small actuation force was designed. Its self-reinforcement feature, associated with different factors such as the wedge angle and friction coefficient, brings different dynamics and unstable problem with improper parameters. To analyze this system, a complete mathematical model of the actuation system is built, which includes the DC motor, the wedge mechanism, and the actuated clutch pack. By considering several nonlinear factors, such as the slip-stick friction and the contact or not of the clutch plates, the system is piecewise linear. Through the stability analysis of the linearized system in clutch slipping phase, the stable condition of the designed parameters is obtained as α>arctan⁡(μc. The mathematical model of the actuation system is validated by prototype testing. And with the validated model, the system dynamics in both stable and unstable conditions is investigated and discussed in engineering side.

  13. Multiple phases and vicious walkers in a wedge

    Directory of Open Access Journals (Sweden)

    Gesualdo Delfino

    2015-12-01

    Full Text Available We consider a statistical system in a planar wedge, for values of the bulk parameters corresponding to a first order phase transition and with boundary conditions inducing phase separation. Our previous exact field theoretical solution for the case of a single interface is extended to a class of systems, including the Blume–Capel model as the simplest representative, allowing for the appearance of an intermediate layer of a third phase. We show that the interfaces separating the different phases behave as trajectories of vicious walkers, and determine their passage probabilities. We also show how the theory leads to a remarkable form of wedge covariance, i.e. a relation between properties in the wedge and in the half plane, which involves the appearance of self-Fourier functions.

  14. Tax wedge in Croatia, Belgium, Estonia, Germany and Slovakia

    Directory of Open Access Journals (Sweden)

    Ana Gabrilo

    2016-06-01

    Full Text Available The aim of this paper is to analyse the taxation of labour income in Croatia, Belgium,Estonia, Germany and Slovakia. Having presented an outline of tax system rules, the paper shows the decomposition of the net average tax wedge for different family types and different income levels based on the OECD methodology. The results show that all observed countries apply a progressive tax schedule, apart from Germany where taxation for higher gross wages is not progressive due to a  cap on the SIC base. When it comes to a taxpayer earning an average gross wage, a Croatian single worker without children has the lowest tax burden, followed by Estonia, Slovakia, Germany and Belgium. However, as regards taxpayers earning 400% of AGW, Estonia has the smallest tax wedge, followed by Slovakia, Germany, Croatia and Belgium. Similar results are obtained by analyzing the tax wedge for couples with two children where one spouse is out of work.

  15. New Transition Wedge Design Composed by Prefabricated Reinforced Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Julia Real-Herráiz

    Full Text Available Abstract Important track degradation occurs in structure-embankment transitions, in which an abrupt change in track vertical stiffness arises, leading to a reduction in passengers comfort and safety. Although granular wedges are suggested by different railroad administrations as a solution to avoid these problems, they present some disadvantages which may affect track long-term performance. In this paper, a new solution designed with prefabricated reinforced concrete slabs is proposed. The aim of this solution is to guarantee a continuous and gradual track vertical stiffness transition in the vicinity of structures, overcoming granular wedges disadvantages. The aim of this study is to assess the performance of the novel wedge design by means of a 3-D FEM model and to compare it with the current solution.

  16. Proximal tibial fracture following anterior cruciate ligament reconstruction surgery: a biomechanical analysis of the tibial tunnel as a stress riser.

    Science.gov (United States)

    Aldebeyan, Wassim; Liddell, Antony; Steffen, Thomas; Beckman, Lorne; Martineau, Paul A

    2017-08-01

    This is the first biomechanical study to examine the potential stress riser effect of the tibial tunnel or tunnels after ACL reconstruction surgery. In keeping with literature, the primary hypothesis tested in this study was that the tibial tunnel acts as a stress riser for fracture propagation. Secondary hypotheses were that the stress riser effect increases with the size of the tunnel (8 vs. 10 mm), the orientation of the tunnel [standard (STT) vs. modified transtibial (MTT)], and with the number of tunnels (1 vs. 2). Tibial tunnels simulating both single bundle hamstring graft (8 mm) and bone-patellar tendon-bone graft (10 mm) either STT or MTT position, as well as tunnels simulating double bundle (DB) ACL reconstruction (7, 6 mm), were drilled in fourth-generation saw bones. These five experimental groups and a control group consisting of native saw bones without tunnels were loaded to failure on a Materials Testing System to simulate tibial plateau fracture. There were no statistically significant differences in peak load to failure between any of the groups, including the control group. The fracture occurred through the tibial tunnel in 100 % of the MTT tunnels (8 and 10 mm) and 80 % of the DB tunnels specimens; however, the fractures never (0 %) occurred through the tibial tunnel of the standard tunnels (8 or 10 mm) (P = 0.032). In the biomechanical model, the tibial tunnel does not appear to be a stress riser for fracture propagation, despite suggestions to the contrary in the literature. Use of a standard, more vertical tunnel decreases the risk of ACL graft compromise in the event of a fracture. This may help to inform surgical decision making on ACL reconstruction technique.

  17. Comparison of tibial shaft ski fractures in children and adults.

    Science.gov (United States)

    Hamada, Tomo; Matsumoto, Kazu; Ishimaru, Daichi; Sumi, Hiroshi; Shimizu, Katsuji

    2014-09-01

    To examine whether child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures. Descriptive epidemiological study. Prospectively analyzed the epidemiologic factors, injury types, and injury mechanisms at Sumi Memorial Hospital. This study analyzed information obtained from 276 patients with tibial fractures sustained during skiing between 2004 and 2012. We focused on 174 ski-related tibial shaft fractures with respect to the following factors: age, gender, laterality of fracture, skill level, mechanism of fracture (fall vs collision), scene of injury (steepness of slope), snow condition, and weather. Fracture pattern was graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification and mechanical direction [external (ER) or internal rotation (IR)]. Tibial shaft fractures were the most common in both children (89.3%) and adults (47.4%). There were no significant differences in gender, side of fracture, mechanism of fracture, snow condition, or weather between children and adults. Skill levels were significantly lower in children than in adults (P differences in some of these parameters, suggesting that child and adult skiers have different risk factors or mechanisms of injury for tibial shaft fractures.

  18. Reconstrucción tibial: transferencia sóleo-peroné ipsilateral. Tibialización peroneal Tibial reconstruction: ipsilateral soleus-fibula transfer. Fibular tibialization

    Directory of Open Access Journals (Sweden)

    E. Revelo Jiron

    2009-12-01

    Full Text Available Las transferencias óseas peroneales en forma libre o ipsilateral han sido propuestas para la reconstrucción de grandes defectos tibiales. Están también descritas varias modificaciones al respecto, siendo una de ellas la constitución de un colgajo compuesto soleo-peroné realizado como transferencia libre. En este estudio presentamos nuestra experiencia con esta variante, pero en forma ipsilateral. logrando la reconstrucción del defecto tibial por medio de la tibialización peroneal. Escogimos realizar un colgajo compuesto soleo-peroné ipsilateral a flujo anterógrado o retrogrado para la reconstrucción de una serie personal de 14 pacientes consecutivos, 13 hombre y 1 mujer, con edad media de 30 años, y con amplios defectos tibiales y de tejidos blandos causados por accidentes de transito en 12 casos, 1 por proyectil balístico y 1 por artefacto explosivo artesanal. El promedio de tamaño del defecto tibial fue de 9.4 cm. Elegimos la forma ipsilateral por no disponer de infraestructura adecuada para realizar una transferencia libre. La serie de estudio se realizó durante el periodo comprendido entre Abril de 1995 y Abril del 2005. Todos los colgajos sobrevivieron. Dos pacientes desarrollaron pseudoartrosis. El apoyo completo y la marcha en 12 pacientes, se logró en un periodo promedio de 9 meses. El seguimiento postoperatorio ha sido de 3 a 6 años. Doce pacientes se han incorporado a la vida activa. Discutimos algunos aspectos prácticos de la técnica como resultado de la experiencia quirúrgica obtenida de esta serie personal. Consideramos que el método es fiable, fácil de realizar y proporciona excelentes resultados.Fibular flaps such as in there free form or as ipsilateral transfers have been proposed for reconstruction of large tibial defects. Several modifications have been described for the use of this flap. In this study we will present our experience using the ipsilateral transfer of an osteomuscular soleous fibular flap

  19. The medial tibial stress syndrome score: Item generation for a new ...

    African Journals Online (AJOL)

    The medial tibial stress syndrome score: Item generation for a new patient reported outcome measure. ... instrument that evaluates injury severity and treatment effects for medial tibial stress syndrome (MTSS) patients. ... from 32 Countries:.

  20. Capillary surfaces in a wedge: Differing contact angles

    Science.gov (United States)

    Concus, Paul; Finn, Robert

    1994-01-01

    The possible zero-gravity equilibrium configurations of capillary surfaces u(x, y) in cylindrical containers whose sections are (wedge) domains with corners are investigated mathematically, for the case in which the contact angles on the two sides of the wedge may differ. In such a situation the behavior can depart in significant qualitative ways from that for which the contact angles on the two sides are the same. Conditions are described under which such qualitative changes must occur. Numerically computed surfaces are depicted to indicate the behavior.

  1. Three-dimensional wedge filling in ordered and disordered systems

    International Nuclear Information System (INIS)

    Greenall, M J; Parry, A O; Romero-Enrique, J M

    2004-01-01

    We investigate interfacial structural and fluctuation effects occurring at continuous filling transitions in 3D wedge geometries. We show that fluctuation-induced wedge covariance relations that have been reported recently for 2D filling and wetting have mean-field or classical analogues that apply to higher-dimensional systems. Classical wedge covariance emerges from analysis of filling in shallow wedges based on a simple interfacial Hamiltonian model and is supported by detailed numerical investigations of filling within a more microscopic Landau-like density functional theory. Evidence is presented that classical wedge covariance is also obeyed for filling in more acute wedges in the asymptotic critical regime. For sufficiently short-ranged forces mean-field predictions for the filling critical exponents and covariance are destroyed by pseudo-one-dimensional interfacial fluctuations. We argue that in this filling fluctuation regime the critical exponents describing the divergence of length scales are related to values of the interfacial wandering exponent ζ(d) defined for planar interfaces in (bulk) two-dimensional (d = 2) and three-dimensional (d = 3) systems. For the interfacial height l w ∼ θ-α) -β w , with θ the contact angle and α the wedge tilt angle, we find β w = ζ(2)/2(1-ζ(3)). For pure systems (thermal disorder) we recover the known result β w = 1/4 predicted by interfacial Hamiltonian studies whilst for random-bond disorder we predict the universal critical exponent β ∼ even in the presence of dispersion forces. We revisit the transfer matrix theory of three-dimensional filling based on an effective interfacial Hamiltonian model and discuss the interplay between breather, tilt and torsional interfacial fluctuations. We show that the coupling of the modes allows the problem to be mapped onto a quantum mechanical problem as conjectured by previous authors. The form of the interfacial height probability distribution function predicted by

  2. Tool life of ceramic wedges during precise turning of tungsten

    Directory of Open Access Journals (Sweden)

    Legutko Stanislaw

    2017-01-01

    Full Text Available Properties, application and machinability of tungsten and its alloys have been demonstrated. The comparison of the tool life and wear of the wedges made of SiAlON and whisker ceramics during the precise turning at different cutting parameters have been presented. The CNC lathe DMG CTX 310 Ecoline and tungsten of 99.7 % purity were used during the experiments. Only the wedge of whisker ceramics has proved to be sufficiently suitable and only for relatively low cutting speeds.

  3. Bracing can partially limit tibial rotation during stressful activities after anterior crucial ligament reconstruction with a hamstring graft.

    Science.gov (United States)

    Giotis, D; Paschos, N K; Zampeli, F; Pappas, E; Mitsionis, G; Georgoulis, A D

    2016-09-01

    Hamstring graft has substantial differences with BPTB graft regarding initial mechanical strength, healing sequence, and vascularization, which may imply that a different approach during rehabilitation period is required. The purpose of this study was to investigate the influence of knee bracing on tibial rotation in ACL-reconstructed patients with a hamstring autograft during high loading activities. The hypothesis was that there would be a decrease in tibial rotation in the ACL-reconstructed braced knee as compared to the unbraced knee. Twenty male patients having undergone unilateral ACL reconstruction with a semitendinosus/gracilis autograft were assessed. Kinematic data were collected with an eight-camera optoelectronic system during two stressful tasks: (1) descending from a stair and subsequent pivoting; and (2) landing from a platform and subsequent pivoting. In each patient, three different experimental conditions were evaluated: (A) wearing a prophylactic brace (braced condition); (B) wearing a patellofemoral brace (sleeved condition); (C) without brace (unbraced condition). The intact knee without brace served as a control. Tibial rotation was significantly lower in the intact knee compared to all three conditions of the ACL-reconstructed knee (P≤0.01 for both tasks). Presence of a brace or sleeve resulted in lower tibial rotation than in the unbraced condition (p=0.003 for descending/pivot and P=0.0004 for landing/pivot). The braced condition resulted in lower rotation than the sleeved condition for descending/pivoting (P=0.031) while no differences were found for landing/pivoting (P=0.230). Knee bracing limited the excessive tibial rotation during pivoting under high loading activities in ACL-reconstructed knees with a hamstring graft. This partial restoration of normal kinematics may have a potential beneficial effect in patients recovering from ACL reconstruction with a hamstring autograft. Level III, case-control therapeutic study. Copyright

  4. Comparison of Different Approaches for Measuring Tibial Cartilage Thickness

    Directory of Open Access Journals (Sweden)

    Maier Jennifer

    2017-07-01

    Full Text Available Osteoarthritis is a degenerative disease affecting bones and cartilage especially in the human knee. In this context, cartilage thickness is an indicator for knee cartilage health. Thickness measurements are performed on medical images acquired in-vivo. Currently, there is no standard method agreed upon that defines a distance measure in articular cartilage. In this work, we present a comparison of different methods commonly used in literature. These methods are based on nearest neighbors, surface normal vectors, local thickness and potential field lines. All approaches were applied to manual segmentations of tibia and lateral and medial tibial cartilage performed by experienced raters. The underlying data were contrast agent-enhanced cone-beam C-arm CT reconstructions of one healthy subject’s knee. The subject was scanned three times, once in supine position and two times in a standing weight-bearing position. A comparison of the resulting thickness maps shows similar distributions and high correlation coefficients between the approaches above 0.90. The nearest neighbor method results on average in the lowest cartilage thickness values, while the local thickness approach assigns the highest values. We showed that the different methods agree in their thickness distribution. The results will be used for a future evaluation of cartilage change under weight-bearing conditions.

  5. All-arthroscopic treatment of tibial avulsion fractures of the posterior cruciate ligament

    Directory of Open Access Journals (Sweden)

    Gwinner, Clemens

    2016-01-01

    Full Text Available Background: The posterior cruciate ligament (PCL avulsion fracture from its tibial insertion is a rare condition. Despite the further technical advent in refixation of avulsion fractures, the reported failure rate of current approaches remains high and the optimal surgical technique has not been elucidated yet.The purpose of the current study is to present an all-inside arthroscopic reconstruction technique for bony tibial avulsion fractures of the PCL and initial clinical outcomes. Methods: Patients underwent a thorough clinical and radiological examination of both knees at 3, 6, 12, 18, and if possible also at 24 months.Clinical evaluation included subjective and objective IKDC 2000, Lysholm score, and KOOS score. Radiographic imaging studies included CT scans for assessment of osseous integration and anatomic reduction of the bony avulsion. In addition to that posterior stress radiographs of both knees using the Telos device (Arthrex, Naples, USA were conducted to measure posterior tibial translation.Results: A total of four patients (1 female, 3 male; ø 38 (± 18 years, who underwent arthroscopic refixation of a PCL avulsion fracture using the Tight Rope device were enrolled in this study. Mean follow up was 22 [18–24] months. The mean subjective IKDC was 72.6% (± 9.9%. Regarding the objective IKDC three patients accounted for grade A, one patient for grade C. The Lysholm score yielded 82 (± 6.9 points. The KOOS score reached 75% (± 13%; symptoms 76%, pain 81%, function 76%, sports 66%, QoL 64%.All patients showed complete osseous integration and anatomic reduction of the bony avulsion. The mean posterior tibial translation at final follow up was 2.8 [0–7] mm. Conclusions: All-arthroscopic treatment of tibial avulsion fractures of the posterior cruciate ligament provides satisfactory clinical results in a preliminary patient cohort. It is a reproducible technique, which minimizes soft tissue damage and obviates a second surgery for

  6. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study

    OpenAIRE

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-ichi

    2017-01-01

    AIM To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). METHODS A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fract...

  7. Fixation strength of biocomposite wedge interference screw in ACL reconstruction: effect of screw length and tunnel/screw ratio. A controlled laboratory study

    Directory of Open Access Journals (Sweden)

    Herrera Antonio

    2010-06-01

    Full Text Available Abstract Background Primary stability of the graft is essential in anterior cruciate ligament surgery. An optimal method of fixation should be easy to insert and provide great resistance against pull-out forces. A controlled laboratory study was designed to test the primary stability of ACL tendinous grafts in the tibial tunnel. The correlation between resistance to traction forces and the cross-section and length of the screw was studied. Methods The tibial phase of ACL reconstruction was performed in forty porcine tibias using digital flexor tendons of the same animal. An 8 mm tunnel was drilled in each specimen and two looped tendons placed as graft. Specimens were divided in five groups according to the diameter and length of the screw used for fixation. Wedge interference screws were used. Longitudinal traction was applied to the graft with a Servohydraulic Fatigue System. Load and displacement were controlled and analyzed. Results The mean loads to failure for each group were 295,44 N (Group 1; 9 × 23 screw, 564,05 N (Group 2; 9 × 28, 614,95 N (Group 3; 9 × 35, 651,14 N (Group 4; 10 × 28 and 664,99 (Group 5; 10 × 35. No slippage of the graft was observed in groups 3, 4 and 5. There were significant differences in the load to failure among groups (ANOVA/P Conclusions Longer and wider interference screws provide better fixation in tibial ACL graft fixation. Short screws (23 mm do not achieve optimal fixation and should be implanted only with special requirements.

  8. Wedged-shaped, segmental changes in the liver caused by occlusion of a single hepatic vein

    International Nuclear Information System (INIS)

    Kanazawa, Susumu; Akaki, Shiro; Yasui, Kotaro; Tanaka, Akio; Hiraki, Yoshio

    1997-01-01

    We evaluated wedged-shaped, segmental changes in the liver caused by occlusion of a single hepatic vein in seven patients. The causes of occlusion were due to liver tumors in three patients, metastasis of the right adrenal gland in one, and postoperative changes in three. Changes included low attenuating on unenhanced CT, high attenuation on enhanced CT, low signal intensity on T1-weighted MRI, high signal intensity on T2-weighted MRI, high signal intensity on enhanced MRI, dense hepatogram and retrograde arterioportal shunt on hepatic arteriography. MRI and hepatic arteriography are more sensitive than CT in demonstration of those changes. (author)

  9. tibialization of the fibula in a child with chronic osteomyelitis of the ...

    African Journals Online (AJOL)

    used in tibial reconstruction after resection of Ewing's sarcoma (6). A case report from Congo detailed how a 10-centimeter tibial bone loss was treated by inter- tibiofibula bone grafting, resulting in tibialization of the fibula. The patient was reviewed after 10 years; and the clinical result was satisfactory and stable (7).

  10. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

  11. External fixation of tibial pilon fractures and fracture healing.

    Science.gov (United States)

    Ristiniemi, Jukka

    2007-06-01

    Distal tibial fractures are rare and difficult to treat because the bones are subcutaneous. External fixation is commonly used, but the method often results in delayed union. The aim of the present study was to find out the factors that affect fracture union in tibial pilon fractures. For this purpose, prospective data collection of tibial pilon fractures was carried out in 1998-2004, resulting in 159 fractures, of which 83 were treated with external fixation. Additionally, 23 open tibial fractures with significant > 3 cm bone defect that were treated with a staged method in 2000-2004 were retrospectively evaluated. The specific questions to be answered were: What are the risk factors for delayed union associated with two-ring hybrid external fixation? Does human recombinant BMP-7 accelerate healing? What is the role of temporary ankle-spanning external fixation? What is the healing potential of distal tibial bone loss treated with a staged method using antibiotic beads and subsequent autogenous cancellous grafting compared to other locations of the tibia? The following risk factors for delayed healing after external fixation were identified: post-reduction fracture gap of >3 mm and fixation of the associated fibula fracture. Fracture displacement could be better controlled with initial temporary external fixation than with early definitive fixation, but it had no significant effect on healing time, functional outcome or complication rate. Osteoinduction with rhBMP-7 was found to accelerate fracture healing and to shorten the sick leave. A staged method using antibiotic beads and subsequent autogenous cancellous grafting proved to be effective in the treatment of tibial bone loss. Healing potential of the bone loss in distal tibia was at least equally good as in other locations of the tibia.

  12. Bone stress in runners with tibial stress fracture.

    Science.gov (United States)

    Meardon, Stacey A; Willson, John D; Gries, Samantha R; Kernozek, Thomas W; Derrick, Timothy R

    2015-11-01

    Combinations of smaller bone geometry and greater applied loads may contribute to tibial stress fracture. We examined tibial bone stress, accounting for geometry and applied loads, in runners with stress fracture. 23 runners with a history of tibial stress fracture & 23 matched controls ran over a force platform while 3-D kinematic and kinetic data were collected. An elliptical model of the distal 1/3 tibia cross section was used to estimate stress at 4 locations (anterior, posterior, medial and lateral). Inner and outer radii for the model were obtained from 2 planar x-ray images. Bone stress differences were assessed using two-factor ANOVA (α=0.05). Key contributors to observed stress differences between groups were examined using stepwise regression. Runners with tibial stress fracture experienced greater anterior tension and posterior compression at the distal tibia. Location, but not group, differences in shear stress were observed. Stepwise regression revealed that anterior-posterior outer diameter of the tibia and the sagittal plane bending moment explained >80% of the variance in anterior and posterior bone stress. Runners with tibial stress fracture displayed greater stress anteriorly and posteriorly at the distal tibia. Elevated tibial stress was associated with smaller bone geometry and greater bending moments about the medial-lateral axis of the tibia. Future research needs to identify key running mechanics associated with the sagittal plane bending moment at the distal tibia as well as to identify ways to improve bone geometry in runners in order to better guide preventative and rehabilitative efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Ischial hypoplasia, tibial hypoplasia and facial abnormalities: a new syndrome?

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, G. [Department of Radiology, Dokkyo University School of Medicine (Japan); Haga, Yoshihiko [Department of Orthopaedics, Shizuoka Children`s Hospital, Shizuoka (Japan); Aoki, Katsuhiko [Department of Radiology, Shizuoka Children`s Hospital, Shizuoka (Japan); Hasegawa, Tomoko [Division of Clinical Genetics, Shizuoka Children`s Hospital, Shizuoka (Japan)

    1998-12-01

    A child with facial abnormalities, short stature and a variety of skeletal alterations is reported. The facial abnormalities comprised low-set ears, short nose with a long philtrum, micrognathia and cleft palate. The skeletal alterations included ischial hypoplasia, malformations of the cervical spine, hypoplasia of the lesser trochanters, tibial hypoplasia with bowing of the lower legs, tibio-fibular diastasis with malformed distal tibial epiphyses, clubfeet and brachymesophalangy. The constellation of clinical and radiological findings in the present patient do not fit any known malformation syndrome. (orig.) With 4 figs., 8 refs.

  14. Expected long-term outcome after a tibial shaft fracture

    DEFF Research Database (Denmark)

    Faergemann, C; Frandsen, P A; Röck, N D

    1999-01-01

    OBJECTIVE: A prospective study of 207 laymen and professionals answered a questionnaire regarding the expectations of the long-term outcome 6 months after a unilateral tibial shaft fracture. The aim was (1) to disclose the expected outcome after unilateral tibial shaft fracture, and (2) to compare...... these expectations with the outcome measured in patients. METHODS: There were five groups of nonpatients: (1) 42 orthopedic surgeons, (2) 36 physiotherapists, (3) 42 students, (4) 49 white collar workers, and (5) 38 blue collar workers. Outcome was measured by Sickness Impact Profile (SIP). The SIP scores were...

  15. Ischial hypoplasia, tibial hypoplasia and facial abnormalities: a new syndrome?

    International Nuclear Information System (INIS)

    Nishimura, G.; Haga, Yoshihiko; Aoki, Katsuhiko; Hasegawa, Tomoko

    1998-01-01

    A child with facial abnormalities, short stature and a variety of skeletal alterations is reported. The facial abnormalities comprised low-set ears, short nose with a long philtrum, micrognathia and cleft palate. The skeletal alterations included ischial hypoplasia, malformations of the cervical spine, hypoplasia of the lesser trochanters, tibial hypoplasia with bowing of the lower legs, tibio-fibular diastasis with malformed distal tibial epiphyses, clubfeet and brachymesophalangy. The constellation of clinical and radiological findings in the present patient do not fit any known malformation syndrome. (orig.)

  16. Posterior tibial neuropathy by a Baker's cyst: case report.

    Science.gov (United States)

    Lee, J H; Jun, J B; Lee, H S; Yun, H R; Choi, C H; Park, S B; Hong, E K; Yoo, D H; Kim, S Y

    2000-01-01

    Baker's cysts are rare cause of peripheral nerve entrapment and only a few cases of tibial nerve entrapment resulting from the popliteal cyst in the calf muscle have been reported in the literature. We present a case of rheumatoid arthritis complicated by a Baker's cyst with a tibial nerve entrapment. It is important to diagnose a Baker's cyst early and to differentiate it from thrombophlebitis, a popliteal aneurysm, tumor or muscle tear to effect optimal therapy and to obviate a potential neuropathy. Prompt recognition of these cases may save the patients unnecessary procedures and delay in treatment.

  17. Tibial and fibular angles in homozygous sickle cell disease

    International Nuclear Information System (INIS)

    Akamaguna, A.I.; Odita, J.C.; Ugbodaga, C.I.; Okafor, L.A.

    1986-01-01

    Measurements of the tibial and fibular angles made on ankle radiographs of 34 patients with sickle cell disease were compared with those of 36 normal Nigerians. Widening of the fibular angle, which is an indication of tibiotalar slant, was demonstrated in about 79% of sickle cell disease patients. By using fibular angle measurements as an objective method of assessing subtle tibiotalar slant, it is concluded that the incidence of this deformity is much higher among sickle cell disease patients than previously reported. The mean values of tibial and fibular angles in normal Nigerians are higher than has been reported amongst Caucasians. (orig.)

  18. Flow Analysis for the Falkner–Skan Wedge Flow

    DEFF Research Database (Denmark)

    Bararnia, H; Haghparast, N; Miansari, M

    2012-01-01

    In this article an analytical technique, namely the homotopy analysis method (HAM), is applied to solve the momentum and energy equations in the case of a two-dimensional incompressible flow passing over a wedge. The trail and error method and Padé approximation strategies have been used to obtai...

  19. Dependence of wedge transmission factor on co-60 teletherapy ...

    African Journals Online (AJOL)

    Measuring the wedge factor (WF) for radiation field of 10 x 10 cm2 at a specified depth and Source to Surface Distance (SSD), and applying the value to all treatment depths and technique could introduce errors > ± 5 % of threshold stipulated for patient radiation dose delivery. Therefore, some Treatment Planning Systems ...

  20. Thoracoscopic pulmonary wedge resection without post-operative chest drain

    DEFF Research Database (Denmark)

    Holbek, Bo Laksafoss; Hansen, Henrik Jessen; Kehlet, Henrik

    2016-01-01

    %) patients had a pneumothorax of mean size 12 ± 12 mm on supine 8-h post-operative X-ray for which the majority resolved spontaneously within 2-week control. There were no complications on 30-day follow-up. Median length of stay was 1 day. CONCLUSIONS: The results support that VATS wedge resection...

  1. Fixed Points of Maps of a Nonaspherical Wedge

    Directory of Open Access Journals (Sweden)

    Merrill Keith

    2009-01-01

    Full Text Available Abstract Let be a finite polyhedron that has the homotopy type of the wedge of the projective plane and the circle. With the aid of techniques from combinatorial group theory, we obtain formulas for the Nielsen numbers of the selfmaps of .

  2. Complex Wedge-Shaped Matrices: A Generalization of Jacobi Matrices

    Czech Academy of Sciences Publication Activity Database

    Hnětynková, Iveta; Plešinger, M.

    2015-01-01

    Roč. 487, 15 December (2015), s. 203-219 ISSN 0024-3795 R&D Projects: GA ČR GA13-06684S Keywords : eigenvalues * eigenvector * wedge-shaped matrices * generalized Jacobi matrices * band (or block) Krylov subspace methods Subject RIV: BA - General Mathematics Impact factor: 0.965, year: 2015

  3. The Hardy inequality and the heat flow in curved wedges

    Czech Academy of Sciences Publication Activity Database

    Krejčiřík, David

    2016-01-01

    Roč. 73, č. 2 (2016), s. 91-113 ISSN 0032-5155 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : Hardy inequality * heat equation * large-time behaviour * curved wedges * Dirichlet Laplacian * conical singularities * Brownian motion * subcriticality Subject RIV: BE - Theoretical Physics Impact factor: 0.735, year: 2016

  4. Elastic Knee Sleeves Limit Anterior Tibial Translation in Healthy Females

    Directory of Open Access Journals (Sweden)

    Robert Csapo, Simona Hosp, Ramona Folie, Robert Eberle, Michael Hasler, Werner Nachbauer

    2016-03-01

    Full Text Available Knee sleeves or braces represent auxiliary tools that have repeatedly been used by athletes, in an attempt to increase knee stability and, thus, reduce the risk of (recurrent ligamentous injuries. Since ACL injuries typically occur in situations involving either torsion or hyperextension of the knee, it has been speculated that braces might protect the ACL by countering excessive anterior translation of the tibia with respect to the femur (Beynnon et al., 1997. However, the preponderance of in vivo studies to test this hypothesis was performed in cohorts of patients suffering from existent ligamentous (Branch et al., 1988; Colville et al., 1986 or other knee injury (Beynnon et al., 1997; Fleming et al., 2000. This complicates the extrapolation of results to healthy subjects. Further, the braces used in these studies were mostly rigid constructs that consisted of either uni- or bilateral hinged bars (Rishiraj et al., 2009. Such braces might hinder performance (Veldhuizen et al., 1991 and would be rejected by the vast majority of healthy athletes. For these reasons, we would like to use this letter to the editor to report the results of our experiments investigating whether a relatively light elastic knee sleeve would limit the degree of anterior tibial translation in computerized arthrometry tests as performed in a sample of non-injured subjects. We recruited ten female college students (age: 23.4 ± 3.2 yrs, height: 1.68 ± 0.05 m, mass: 59.9 ± 5.5 kg who were free of acute or previous injury or any form of orthopaedic disease of the knee joints. The anterior displacement of the tibia was measured using the GNRB® computerized arthrometer (GeNouRob, Laval, France. With subjects lying in the supine position, the lower leg was firmly fixed with plastic caps mounted over the ankle joint and patella. An electrical pressure pad then exerted increasing pressure of up to 250 N on the calf, while a motion sensor, which was positioned on the ventral

  5. Effects of Added Mass and Structural Damping on Dynamic Responses of a 3D Wedge Impacting on Water

    Directory of Open Access Journals (Sweden)

    Pengyao Yu

    2018-05-01

    Full Text Available The impact between the wave and the bottom of a high-speed vessel is often simplified as water-entry problems of wedges. Most investigations focus on the water entry of two dimensional (2D wedges. The effects of added mass and structural damping are still not fully investigated. By combining the normal mode method, the hydrodynamic impact model of rigid wedges and the potential flow theory, a dynamic model for predicting the response of a three dimensional (3D wedge impacting on water with a constant velocity is established in this paper. The present model can selectively consider the effects of the added mass and the structural damping. The present method has been validated through comparisons with results of published literatures and commercial software. It is found that the added mass can increase the stress response before the flow separation, and reduce the vibration frequency after the flow separation. Due to the effect of the added mass, the stress response of some positions after the flow separation is even higher than that before the flow separation. The structural damping has a negligible effect on the stress before the flow separation, but it can reduce vibration stress after the flow separation.

  6. Arc-parallel extension and fluid flow in an ancient accretionary wedge: The San Juan Islands, Washington

    Science.gov (United States)

    Schermer, Elizabeth R.; Gillaspy, J.R.; Lamb, R.

    2007-01-01

    Structural analysis of the Lopez Structural Complex, a major Late Cretaceous terrane-bounding fault zone in the San Juan thrust system, reveals a sequence of events that provides insight into accretionary wedge mechanics and regional tectonics. After formation of regional ductile flattening and shear-related fabrics, the area was crosscut by brittle structures including: (1) southwest-vergent thrusts, (2) extension veins and normal faults related to northwest-southeast extension, and (3) conjugate strike-slip structures that record northwest-southeast extension and northeast-southwest shortening. Aragonite-bearing veins are associated with thrust and normal faults, but only rarely with strike-slip faults. High-pressure, low-temperature (HP-LT) minerals constrain the conditions for brittle deformation to ???20 km and formed in an accretionary prism during active subduction, which suggests that these brittle structures record internal wedge deformation at depth and early during uplift of the San Juan nappes. The structures are consistent with orogen-normal shortening and vertical thickening followed by vertical thinning and along-strike extension. The kinematic evolution may be related initially to changes in wedge strength, followed by response to overthickening of the wedge in an unbuttressed, obliquely convergent setting. The change in vein mineralogy indicates that exhumation occurred prior to the strike-slip event. The pressure and temperature conditions and spatial and temporal extent of small faults associated with fluid flow suggest a link between these structures and the silent earthquake process. ?? 2007 Geological Society of America.

  7. Therapy by stationary photon fields from a 42 MeV betatron using wedge filters

    International Nuclear Information System (INIS)

    Wicke, L.; Kaercher, K.H.; Naesiger, H.; Prokosch, E.; Vienna Univ.

    1975-01-01

    The dose distribution in photon beams from a 42 MeV betatron using wedge filters of lead with different angles of slope is described. The wedge coefficient to be considered at a field size of 10 x 10 cm is given. The scope for isodoses modified by wedge filters is discussed with regard to stationary-field photon therapy. (orig.) [de

  8. A practical method to calculate head scatter factors in wedged rectangular and irregular MLC shaped beams for external and internal wedges

    International Nuclear Information System (INIS)

    Georg, Dietmar; Olofsson, Joergen; Kuenzler, Thomas; Aiginger, Hannes; Karlsson, Mikael

    2004-01-01

    Factor based methods for absorbed dose or monitor unit calculations are often based on separate data sets for open and wedged beams. The determination of basic beam parameters can be rather time consuming, unless equivalent square methods are applied. When considering irregular wedged beams shaped with a multileaf collimator, parametrization methods for dosimetric quantities, e.g. output ratios or wedge factors as a function of field size and shape, become even more important. A practical method is presented to derive wedged output ratios in air (S c,w ) for any rectangular field and for any irregular MLC shaped beam. This method was based on open field output ratios in air (S c ) for a field with the same collimator setting, and a relation f w between S c,w and S c . The relation f w can be determined from measured output ratios in air for a few open and wedged fields including the maximum wedged field size. The function f w and its parametrization were dependent on wedge angle and treatment head design, i.e. they were different for internal and external wedges. The proposed method was tested for rectangular wedged fields on three accelerators with internal wedges (GE, Elekta, BBC) and two accelerators with external wedges (Varian). For symmetric regular beams the average deviation between calculated and measured S c,w /S c ratios was 0.3% for external wedges and about 0.6% for internal wedges. Maximum deviations of 1.8% were obtained for elongated rectangular fields on the GE and ELEKTA linacs with an internal wedge. The same accuracy was achieved for irregular MLC shaped wedged beams on the accelerators with MLC and internal wedges (GE and Elekta), with an average deviation <1% for the fields tested. The proposed method to determine output ratios in air for wedged beams from output ratios of open beams, combined with equivalent square approaches, can be easily integrated in empirical or semi-empirical methods for monitor unit calculations

  9. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study.

    Science.gov (United States)

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-Ichi

    2017-06-18

    To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI. Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI. We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

  10. Anterior cruciate ligament reconstruction failure after tibial shaft malunion.

    Science.gov (United States)

    LaFrance, Russell M; Gorczyca, John T; Maloney, Michael D

    2012-02-17

    Anterior cruciate ligament (ACL) reconstruction is common, with >100,000 procedures performed each year in the United States. Several factors are associated with failure, including poor surgical technique, graft incorporation failure, overly aggressive rehabilitation, and trauma. Tibial shaft fracture is also common and frequently requires operative intervention. Failure to reestablish the anatomic alignment of the tibia may cause abnormal forces across adjacent joints, which can cause degenerative joint disease or attritional failure of the surrounding soft tissues. This article describes a case of ACL reconstruction failure after a tibial fracture that resulted in malunion. Excessive force across the graft from lower-extremity malalignment and improper tunnel placement likely contributed to the attritional failure of the graft. This patient required a staged procedure for corrective tibial osteotomy followed by revision ACL reconstruction. This article describes ACL reconstruction failure, tibial shaft malunions, their respective treatments, the technical details of each procedure, and the technical aspects that must be considered when these procedures are done in a staged manner by 2 surgeons. Copyright 2012, SLACK Incorporated.

  11. Preliminary evaluation of the tibial tuberosity-trochlear groove measurement

    DEFF Research Database (Denmark)

    Miles, James Edward; Kirpensteijn, Jolle; Svalastoga, Eiliv Lars

    guide surgical treatment. The TTTG measures tibial tuberosity position relative to the axis of the femoral trochlea. A preliminary investigation of TTTG measurement was performed using the red fox (Vulpes vulpes) cadavers as a morphologically similar and homogenous substitute for dog cadavers. CT...

  12. Displaced tibial shaft fractures treated with ASIF compression internal fixation

    DEFF Research Database (Denmark)

    Gebuhr, Peter Henrik; Larsen, T K; Petersen, O C

    1990-01-01

    Fifty-one tibial shaft fractures treated by ASIF compression osteosynthesis were seen at follow-up at a median time of 46 weeks after injury. Twenty-four were open fractures and the patients received prophylactic antibiotics. The median stay in hospital was 15 days for open fractures and 6 days f...

  13. Epidemiology of open tibial fractures in a teaching hospital ...

    African Journals Online (AJOL)

    Methods: This is a prospective observational study of all open tibial fractures seen at the Accident and Emergency department of the University of Port Harcourt Teaching Hospital (UPTH) over a twelve- month period (July 2002- June 2003). Data from a pre-designed proforma for the study was analyzed and descriptive ...

  14. Tibial dyschondroplasia associated proteomic changes in chicken growth plate cartilage

    Science.gov (United States)

    Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of tibia preventing its transition to bone. To understand the disease-induced proteomic changes we compared the protein extracts of cartilage from normal and TD- affected growth plates. TD was induced by fe...

  15. Medial Tibial Stress Syndrome : Diagnosis, Treatment and Outcome Assessment

    NARCIS (Netherlands)

    Winters, M.

    2017-01-01

    Medial tibial stress syndrome (MTSS), also known as shin splints, is one of the most common sports injuries. Although 20% of the jumping and running athletes have MTSS at some point while engaging in sporting activities, we know little about it. There is a lack of knowledge regarding making the

  16. Aetiology, imaging and treatment of medial tibial stress syndrome

    NARCIS (Netherlands)

    Moen, M.H.

    2012-01-01

    The work contained is this thesis discusses aetiology, imaging and treatment of a common leg injury: medial tibial stress syndrome (MTSS). Although a common injury, the number of scientific articles on this topic is relatively low as is explained in chapter 1. This chapter also highlights that the

  17. Posterior tibial tendon dysfunction by bone imprisonment | Zejjari ...

    African Journals Online (AJOL)

    The posterior tibial muscle is the main functional support of the plantar arch its dysfunction is the main cause of acquired flat foot. This is a 32 year old patient who consults for progressive pain of the inside of the ankle and right foot with a considerable decrease in its sporting and professional activity. Examination reveals a ...

  18. Experimental investigation of sound absorption of acoustic wedges for anechoic chambers

    Science.gov (United States)

    Belyaev, I. V.; Golubev, A. Yu.; Zverev, A. Ya.; Makashov, S. Yu.; Palchikovskiy, V. V.; Sobolev, A. F.; Chernykh, V. V.

    2015-09-01

    The results of measuring the sound absorption by acoustic wedges, which were performed in AC-3 and AC-11 reverberation chambers at the Central Aerohydrodynamic Institute (TsAGI), are presented. Wedges of different densities manufactured from superfine basaltic and thin mineral fibers were investigated. The results of tests of these wedges were compared to the sound absorption of wedges of the operating AC-2 anechoic facility at TsAGI. It is shown that basaltic-fiber wedges have better sound-absorption characteristics than the investigated analogs and can be recommended for facing anechoic facilities under construction.

  19. Pathomorphism of spiral tibial fractures in computed tomography imaging.

    Science.gov (United States)

    Guzik, Grzegorz

    2011-01-01

    Spiral fractures of the tibia are virtually homogeneous with regard to their pathomorphism. The differences that are seen concern the level of fracture of the fibula, and, to a lesser extent, the level of fracture of the tibia, the length of fracture cleft, and limb shortening following the trauma. While conventional radiographs provide sufficient information about the pathomorphism of fractures, computed tomography can be useful in demonstrating the spatial arrangement of bone fragments and topography of soft tissues surrounding the fracture site. Multiple cross-sectional computed tomography views of spiral fractures of the tibia show the details of the alignment of bone chips at the fracture site, axis of the tibial fracture cleft, and topography of soft tissues that are not visible on standard radiographs. A model of a spiral tibial fracture reveals periosteal stretching with increasing spiral and longitudinal displacement. The cleft in tibial fractures has a spiral shape and its line is invariable. Every spiral fracture of both crural bones results in extensive damage to the periosteum and may damage bellies of the long flexor muscle of toes, flexor hallucis longus as well as the posterior tibial muscle. Computed tomography images of spiral fractures of the tibia show details of damage that are otherwise invisible on standard radiographs. Moreover, CT images provide useful information about the spatial location of the bone chips as well as possible threats to soft tissues that surround the fracture site. Every spiral fracture of the tibia is associated with disruption of the periosteum. 1. Computed tomography images of spiral fractures of the tibia show details of damage otherwise invisible on standard radiographs, 2. The sharp end of the distal tibial chip can damage the tibialis posterior muscle, long flexor muscles of the toes and the flexor hallucis longus, 3. Every spiral fracture of the tibia is associated with disruption of the periosteum.

  20. The optimisation of wedge filters in radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Oldham, Mark; Neal, Anthony J.; Webb, Steve

    1995-01-01

    A treatment plan optimisation algorithm has been applied to 12 patients with early prostate cancer in order to determine the optimum beam-weights and wedge angles for a standard conformal three-field treatment technique. The optimisation algorithm was based on fast-simulated-annealing using a cost function designed to achieve a uniform dose in the planning-target-volume (PTV) and to minimise the integral doses to the organs-at-risk. The algorithm has been applied to standard conformal three-field plans created by an experienced human planner, and run in three PLAN MODES: (1) where the wedge angles were fixed by the human planner and only the beam-weights were optimised; (2) where both the wedge angles and beam-weights were optimised; and (3) where both the wedge angles and beam-weights were optimised and a non-uniform dose was prescribed to the PTV. In the latter PLAN MODE, a uniform 100% dose was prescribed to all of the PTV except for that region that overlaps with the rectum where a lower (e.g., 90%) dose was prescribed. The resulting optimised plans have been compared with those of the human planner who found beam-weights by conventional forward planning techniques. Plans were compared on the basis of dose statistics, normal-tissue-complication-probability (NTCP) and tumour-control-probability (TCP). The results of the comparison showed that all three PLAN MODES produced plans with slightly higher TCP for the same rectal NTCP, than the human planner. The best results were observed for PLAN MODE 3, where an average increase in TCP of 0.73% (± 0.20, 95% confidence interval) was predicted by the biological models. This increase arises from a beneficial dose gradient which is produced across the tumour. Although the TCP gain is small it comes with no increase in treatment complexity, and could translate into increased cures given the large numbers of patients being referred. A study of the beam-weights and wedge angles chosen by the optimisation algorithm revealed

  1. Application of a wedge strip anode in micro-pattern gaseous detectors

    International Nuclear Information System (INIS)

    Tian Yang; Yang Yigang; Li Yulan; Li Yuanjing

    2013-01-01

    The wedge strip anode (WSA) has been widely used in 2-D position-sensitive detectors. A circular WSA with an effective diameter of 52 mm is successfully coupled to a tripe gas electron multiplier (GEM) detector through a simple resistive layer. A spatial resolution of 440 μm (FWHM) is achieved for a 10 kVp X-ray using 1 atm Ar:CO 2 =70:30 gas. The simple electronics of only three channels makes it very useful in applications strongly requiring simple interface design, e.g. sealed tubes and high pressure detectors. (authors)

  2. Variation in Depth Dose Data between Open and Wedge Fields for 6 MV X-Rays

    International Nuclear Information System (INIS)

    U, Hong; Ryu, M. S. Samuel; Park, In Kyu

    1989-01-01

    Central axis depth dose data for 6 MV X-rays, including tissue maximum ratios, were measured for wedge fields according to Tatcher equation. In wedge fields, the differences in magnitude which increased with depth, field size, and wedge thickness increased when compared with the corresponding open field data. However, phantom scatter correction factors for wedge fields differed less that 1% from the corresponding open field factors. The differences in central axis percent depth dose between two types of fields indicated beam hardening by the wedge filter. The deviation of percent depth doses and scatter correction factors between the effective wedge field and the nominal wedge field at same angle was negligible. The differences were less than 3.26% between the nominal or effective wedge fields and the open fields for percent depth doses to the depth 7cm in 6cm x 6cm field. For larger (10cm x 10cm) field size, however, the deviation of percent depth doses between the nominal or effective wedge fields and the open fields were greater-dosimetric errors were 3.56% at depth 7cm and nearly 5.30% at 12cm. We suggest that the percent depth doses of individual wedge and wedge transmission factors should be considered for the dose calculation or monitor setting in the treatment of deep seated tumor

  3. Wakefield and the diffraction model due to a flat beam moving past a conducting wedge

    International Nuclear Information System (INIS)

    Chao, A.W.; Henke, H.

    1995-07-01

    A collimator is often used to clean a beam of its excessive tail particles. If the beam intensity is high enough or if the beam is brought too close to the collimator, however, the wakefields generated by the beam-collimator interaction can cause additional beam tails to grow, thus defeating, or even worsening, the beam-tail cleaning process. The wakefield generated by a sheet beam moving past a conducting wedge has been obtained in closed form by Henke using the method of conformal mapping. This result is applied in the present work to obtain the wake force and the transverse kick received by a test charge moving with the beam. For the beam to be approximated as sheet beams, it is assumed to be flat and the collimator is assumed to have an infinite extent in the flat dimention. We derive an exact expression for the transverse wake force delivered to particles in the beam bunch. Implication of emittance growth as a beam passes closely by a collimator is discussed. We consider two idealized wedge geometries: In Section 2, when the wedge has the geometry as a disrupted beam pipe, and in Section 3, when it is like a semi-infinite screen. Unfortunately, we do not have solutions for more realistic collimator geometries such as when it is tapered to minimize the wakefield effects. However, our results should still serve as pessimistic limiting cases. An interesting opportunity is offered by our exact calculation of the wakefields: it can be used to confront the diffraction model used to estimate the high-frequency impedance of a cavity structure. It is shown that the field pattern, as well as the impedance, agrees with those obtained by the diffraction model in appropriate limits

  4. Effectiveness of Minimally Invasive Plate Osteosynthesis (MIPO on Comminuted Tibial or Femoral Fractures

    Directory of Open Access Journals (Sweden)

    Ali Andalib

    2017-09-01

    Full Text Available Background: Comminuted fractures happen frequently due to traumas. Fixation without opening the fracture site,known as minimally invasive plate osteosynthesis (MIPO, has recently become prevalent. This study has beendesigned to assess the outcomes of this treatment for tibial and femoral comminuted fractures.Methods: A total of 60 patients with comminuted femoral or tibial fractures were operated with MIPO method in thiscross-sectional study at Alzahra university hospital in 2015. Eleven patients were excluded due to lack of adequatefollow-ups. Patients’data including union time; infection in the fractured site; hip and knee range of motion; and anymalunion or deformities like limb length discrepancy were collected after the surgery in every session.Results: Among 32 femoral and 17 tibial fractures, union was completed in48 patients, while only one patient withfemoral fracture had nonunion. The mean union time was 18.57±2.42 weeks. Femur fractures healed faster than tibia(17.76±2.36 compared to 19±2.37 weeks, respectively, P=0.09. None of the patients suffered from infections or fistula.The range of motion in hip and knee remained intact in approximately all patients. Malunion happened in 3 patients; 100internal rotation in 1 patient; and 1cm limb shortening in 2 patients.Conclusion: According to the result of this study, MIPO is a simple and effective method of fixation with a high rateof union as well as minimal complications for comminuted fractures of long bones. Infection is rare, and malunion orany deformity is infrequent. MIPO appears to be a promising and safe treatment alternative for comminuted fractures.

  5. 脉冲 Er:YAG 激光与常规涡轮高速车针治疗楔状缺损的效果比较%The Effect Comparasion between the Pulse Er:YAG Laser and the Conventional Turbine High-speed Dental Bur to the Remedy of Teeth Wedge-shaped Defect

    Institute of Scientific and Technical Information of China (English)

    范伟; 贺慧霞

    2015-01-01

    目的:比较Er:YAG激光与常规涡轮机高速车针治疗楔状缺损的效果。方法收集我院口腔科就诊的、双侧多个同名牙楔状缺损患者85例382颗牙,随机分为激光组和涡轮机组各191牙,其中每位患者每侧至少2颗牙采用激光表面预备,对侧高速涡轮机预备,脉冲照射采用激光剂量为300 mJ,20 Hz间歇操作。涡轮机组采用高速车针制备固位型,自体对照,两组均预备后光固化树脂黏充填。比较两组治疗后1周、1个月、6个月、12个月术后充填物保存率、边缘着色、继发龋等指标,评价其临床治疗效果。结果两组术中疼痛牙齿发生率激光组(16.7%)显著少于涡轮机组(74.8%),差异有统计学意义(P<0.05);术后1周、1个月激光组分别有35牙和12牙出现冷热刺激痛,而涡轮机组发生刺激痛分别为83牙和44牙,两者差异有统计学意义( P<0.05);术后6个月和12个月修复体保存率激光组显著高于涡轮机组,差异有统计学意义( P<0.05);但边缘适合性、边缘着色和继发龋发生率两组差异无统计学意义。结论激光组较涡轮机组在楔状缺损治疗中疼痛发生率低、治疗后疼痛反应轻;修复体保存率高。300 mJ,20 Hz的Er:YAG激光治疗楔状缺损具有无痛、安全、高效的优点。%Objective To compare the effects of Er: YAG laser and conventional high-speed burr in treatment of wedge-shaped tooth defects and to evaluate its applicability and reliability .Methods 382 bilateral multiple teeth with wedge-shaped defects in 85 patients were randomly divided into two groups with 191 teeth in each:laser group and the turbine burr group .At least two teeth of one side in all patients were irradiated by pulsed Er:YAG laser with doses of 300 mj, 20 Hz.Meanwhile, the caries cavities on the contralateral were prepared by high-speed burr .Then the prepared caries defects in both

  6. Tibial Eminence Involvement With Tibial Plateau Fracture Predicts Slower Recovery and Worse Postoperative Range of Knee Motion.

    Science.gov (United States)

    Konda, Sanjit R; Driesman, Adam; Manoli, Arthur; Davidovitch, Roy I; Egol, Kenneth A

    2017-07-01

    To examine 1-year functional and clinical outcomes in patients with tibial plateau fractures with tibial eminence involvement. Retrospective analysis of prospectively collected data. Academic Medical Center. All patients who presented with a tibial plateau fracture (Orthopaedic Trauma Association (OTA) 41-B and 41-C). Patients were divided into fractures with a tibial eminence component (+TE) and those without (-TE) cohorts. All patients underwent similar surgical approaches and fixation techniques for fractures. No tibial eminence fractures received fixation specifically. Short musculoskeletal functional assessment (SMFA), pain (Visual Analogue Scale), and knee range-of-motion (ROM) were evaluated at 3, 6, and 12 months postoperatively and compared between cohorts. Two hundred ninety-three patients were included for review. Patients with OTA 41-C fractures were more likely to have an associated TE compared with 41-B fractures (63% vs. 28%, P knee ROM (75.16 ± 51 vs. 86.82 ± 53 degree, P = 0.06). At 6 months, total SMFA and knee ROM was significantly worse in the +TE cohort (29 ± 17 vs. 21 ± 18, P ≤ 0.01; 115.6 ± 20 vs. 124.1 ± 15, P = 0.01). By 12 months postoperatively, only knee ROM remained significantly worse in the +TE cohort (118.7 ± 15 vs. 126.9 ± 13, P time points. Knee ROM remains worse throughout the postoperative period in the +TE cohort. Functional outcome improves less rapidly in the +TE cohort but achieves similar results by 1 year. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

  7. Interpretation and inverse analysis of the wedge splitting test

    DEFF Research Database (Denmark)

    Østergaard, Lennart; Stang, Henrik

    2002-01-01

    to the wedge splitting test and that it is well suited for the interpretation of test results in terms of s(w). A fine agreement between the hinge and FEM-models has been found. It has also been found that the test and the hinge model form a solid basis for inverse analysis. The paper also discusses possible...... three dimensional problems in the experiment as well as the influence of specimen size....

  8. New Transition Wedge Design Composed by Prefabricated Reinforced Concrete Slabs

    OpenAIRE

    Real-Herráiz, Julia; Zamorano-Martín, Clara; Real-Herráiz, Teresa; Morales-Ivorra, Silvia

    2016-01-01

    [EN] Important track degradation occurs in structure-embankment transitions, in which an abrupt change in track vertical stiffness arises, leading to a reduction in passengers comfort and safety. Although granular wedges are suggested by different railroad administrations as a solution to avoid these problems, they present some disadvantages which may affect track long-term performance. In this paper, a new solution designed with prefabricated reinforced concrete slabs is proposed. The aim of...

  9. Partially wedged beams improve radiotherapy treatment of urinary bladder cancer

    International Nuclear Information System (INIS)

    Muren, Ludvig Paul; Hafslund, Rune; Gustafsson, Anders; Smaaland, Rune; Dahl, Olav

    2001-01-01

    Background and purpose: Partially wedged beams (PWBs) having wedge in one part of the field only, can be shaped using dynamic jaw intensity modulation. The possible clinical benefit of PWBs was tested in treatment plans for muscle-infiltrating bladder cancer. Material and methods: Three-dimensional treatment plans for 25 bladder cancer patients were analyzed. The originally prescribed standard conformal four-field box technique, which includes the use of lateral ordinary wedge beams, was compared to a modified conformal treatment using customized lateral PWBs. In these modified treatment plans, only the anterior parts of the two lateral beams had a wedge. To analyze the potential clinical benefit of treatment with PWBs, treatment plans were scored and compared using both physical parameters and biological dose response models. One tumour control probability model and two normal tissue complication probability (NTCP) models were applied. Different parameters for normal tissue radiation tolerance presented in the literature were used. Results: By PWBs the dose homogeneity throughout the target volume was improved for all patients, reducing the average relative standard deviation of the target dose distribution from 2.3 to 1.8%. A consistent reduction in the maximum doses to surrounding normal tissue volumes was also found. The most notable improvement was demonstrated in the rectum where the volume receiving more than the prescribed tumour dose was halved. Treatment with PWBs would permit a target dose escalation of 2-6 Gy in several of the patients analyzed, without increasing the overall risk for complications. The number of patients suitable for dose escalation ranged from 3 to 15, depending on whether support from all or only one of the five applied NTCP model/parameter combinations were required in each case to recommend dose escalation. Conclusion: PWBs represent a simple dose conformation tool that may allow radiation dose escalation in the treatment of muscle

  10. Spatial resolution of wedge shaped silicon microstrip detectors

    International Nuclear Information System (INIS)

    Anticic, T.; Barnett, B.; Blumenfeld, B.; Chien, C.Y.; Fisher, P.; Gougas, A.; Krizmanic, J.; Madansky, L.; Newman, D.; Orndorff, J.; Pevsner, A.; Spangler, J.

    1995-01-01

    Several wedge-shaped silicon microstrip detectors with pitches from 30 to 100 μm have been designed by our group and beam tested at the CERN SPS. We find the spatial resolution σ becomes larger at the rate of 0.21 μm per 1 μm increase in pitch, but the number of strips per cluster remains about the same as the pitch varies from 30 to 100 μm. (orig.)

  11. Tibial torsion in non-arthritic Indian adults: A computer tomography study of 100 limbs

    Directory of Open Access Journals (Sweden)

    Mullaji Arun

    2008-01-01

    Full Text Available Background: Knowledge of normal tibial torsion is mandatory during total knee replacement (TKR, deformity correction and fracture management of tibia. Different values of tibial torsion have been found in different races due to biological and mechanical factors. Value of normal tibial torsion in Indian limbs is not known, hence this study to determine the norm of tibial torsional value in normal Indian population. Materials and Methods: Computer tomography (CT scans were performed in 100 non-arthritic limbs of 50 Indian adults (42 males, eight females; age 26-40 years. Value of tibial torsion was measured using dorsal tangent to tibial condyles proximally and bimalleolar axis distally. Results: Normal tibial torsion was found to be 21.6 ± 7.6 (range 4.8 to 39.5 with none of the values in internal rotation. Right tibia was externally rotated by 2 degrees as compared to the left side ( P 0.029. No significant difference was found in male and female subjects. Value of tibial torsion was less than in Caucasian limbs, but was comparable to Japanese limbs when studies using similar measurement technique were compared. Conclusions: Indian limbs have less tibial torsion than Caucasian limbs but the value of tibial torsion is comparable to Japanese limbs.

  12. A cluster randomised stepped wedge trial to evaluate the effectiveness of a multifaceted information technology-based intervention in reducing high-risk prescribing of non-steroidal anti-inflammatory drugs and antiplatelets in primary medical care: The DQIP study protocol

    Directory of Open Access Journals (Sweden)

    Dreischulte Tobias

    2012-03-01

    Full Text Available Abstract Background High-risk prescribing of non-steroidal anti-inflammatory drugs (NSAIDs and antiplatelet agents accounts for a significant proportion of hospital admissions due to preventable adverse drug events. The recently completed PINCER trial has demonstrated that a one-off pharmacist-led information technology (IT-based intervention can significantly reduce high-risk prescribing in primary care, but there is evidence that effects decrease over time and employing additional pharmacists to facilitate change may not be sustainable. Methods/design We will conduct a cluster randomised controlled with a stepped wedge design in 40 volunteer general practices in two Scottish health boards. Eligible practices are those that are using the INPS Vision clinical IT system, and have agreed to have relevant medication-related data to be automatically extracted from their electronic medical records. All practices (clusters that agree to take part will receive the data-driven quality improvement in primary care (DQIP intervention, but will be randomised to one of 10 start dates. The DQIP intervention has three components: a web-based informatics tool that provides weekly updated feedback of targeted prescribing at practice level, prompts the review of individual patients affected, and summarises each patient's relevant risk factors and prescribing; an outreach visit providing education on targeted prescribing and training in the use of the informatics tool; and a fixed payment of 350 GBP (560 USD; 403 EUR up front and a small payment of 15 GBP (24 USD; 17 EUR for each patient reviewed in the 12 months of the intervention. We hypothesise that the DQIP intervention will reduce a composite of nine previously validated measures of high-risk prescribing. Due to the nature of the intervention, it is not possible to blind practices, the core research team, or the data analyst. However, outcome assessment is entirely objective and automated. There will

  13. Staged minimally invasive plate osteosynthesis of proximal tibial fractures with acute compartment syndrome.

    Science.gov (United States)

    Kim, Joon-Woo; Oh, Chang-Wug; Oh, Jong-Keon; Kyung, Hee-Soo; Park, Kyeong-Hyeon; Kim, Hee-June; Jung, Jae-Wook; Jung, Young-Soo

    2017-06-01

    High-energy proximal tibial fractures often accompany compartment syndrome and are usually treated by fasciotomy with external fixation followed by secondary plating. However, the initial soft tissue injury may affect bony union, the fasciotomy incision or external fixator pin sites may lead to postoperative wound infections, and the staged procedure itself may adversely affect lower limb function. We assess the results of staged minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures with acute compartment syndrome. Twenty-eight patients with proximal tibial fractures accompanied by acute compartment syndrome who underwent staged MIPO and had a minimum of 12 months follow-up were enrolled. According to the AO/OTA classification, 6 were 41-A, 15 were 41-C, 2 were 42-A and 5 were 42-C fractures; this included 6 cases of open fractures. Immediate fasciotomy was performed once compartment syndrome was diagnosed and stabilization of the fracture followed using external fixation. After the soft tissue condition normalized, internal conversion with MIPO was done on an average of 37 days (range, 9-158) after index trauma. At the time of internal conversion, the external fixator pin site grades were 0 in 3 cases, 1 in 12 cases, 2 in 10 cases and 3 in 3 cases, as described by Dahl. Radiographic assessment of bony union and alignment and a functional assessment using the Knee Society Score and American Orthopedic Foot and Ankle Society (AOFAS) score were carried out. Twenty-six cases achieved primary bony union at an average of 18.5 weeks. Two cases of nonunion healed after autogenous bone grafting. The mean Knee Society Score and the AOFAS score were 95 and 95.3 respectively, at last follow-up. Complications included 1 case of osteomyelitis in a patient with a grade IIIC open fracture and 1 case of malunion caused by delayed MIPO due to poor wound conditions. Duration of external fixation and the external fixator pin site grade were not related to the

  14. Complex Anisotropic Structure of the Mantle Wedge Beneath Kamchatka Volcanoes

    Science.gov (United States)

    Levin, V.; Park, J.; Gordeev, E.; Droznin, D.

    2002-12-01

    A wedge of mantle material above the subducting lithospheric plate at a convergent margin is among the most dynamic environments of the Earth's interior. Deformation and transport of solid and volatile phases within this region control the fundamental process of elemental exchange between the surficial layers and the interior of the planet. A helpful property in the study of material deformation and transport within the upper mantle is seismic anisotropy, which may reflect both microscopic effects of preferentialy aligned crystals of olivine and orthopyroxene and macroscopic effects of systematic cracks, melt lenses, layering etc. Through the mapping of anisotropic properties within the mantle wedge we can establish patterns of deformation. Volatile content affects olivine alignment, so regions of anomalous volatile content may be evident. Indicators of seismic anisotropy commonly employed in upper mantle studies include shear wave birefringence and mode-conversion between compressional and shear body waves. When combined together, these techniques offer complementary constraints on the location and intensity of anisotropic properties. The eastern coast of southern Kamchatka overlies a vigorous convergent margin where the Pacific plate descends at a rate of almost 80 mm/yr towards the northwest. We extracted seismic anisotropy indicators from two data sets sensitive to the anisotropic properties of the uppermost mantle. Firstly, we evaluated teleseismic receiver functions for a number of sites, and found ample evidence for anisotropicaly-influenced P-to-S mode conversion. Secondly, we measured splitting in S waves of earthquakes with sources within the downgoing slab. The first set of observations provides constraints on the depth ranges where strong changes in anisotropic properties take place. The local splitting data provides constraints on the cumulative strength of anisotropic properties along specific pathways through the mantle wedge and possibly parts of

  15. Significance of radiographic abnormalities in patients with tibial stress injuries: correlation with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kijowski, Richard; Choi, James; Smet, Arthur de; Mukharjee, Rajat

    2007-01-01

    The objective was to correlate radiographic findings with magnetic resonance imaging (MRI) findings in patients with suspected tibial stress injuries in order to determine the significance of radiographic signs of stress injury in these individuals. The study group consisted of 80 patients with suspected tibial stress injuries who underwent a radiographic and MR examination of the tibia. Nineteen patients had bilateral involvement. Thus, a total of 99 tibias were evaluated. All radiographs and MR examinations were retrospectively reviewed, 1 month apart, in consensus by two musculoskeletal radiologists. The radiographs were reviewed without knowledge of the site of the clinical symptoms. Fisher's exact tests were used to determine the association between a positive radiograph and the presence of various MRI signs of a high-grade stress injury. There was a strong association between the presence of periosteal reaction on radiographs at the site of the clinical symptoms and a Fredericson grade 4 stress injury on MRI. The presence of periosteal reaction on radiographs at the site of clinical symptoms is predictive of a high-grade stress injury by MRI criteria. (orig.)

  16. Sintesis Bahan Dasar Tibial Tray Berbasis HDPE Yang Diperkuat Dengan Iradiasi Gamma

    Directory of Open Access Journals (Sweden)

    Sulistioso Giat S.

    2014-04-01

    Full Text Available Tibial tray yang sudah komersil dibuat dari Polimer Ultra High Molecular Weight Polyethylene (UHMWPE tetapi harganya sangat mahal. Oleh karena itu pada penelitian ini digunakan polimer High Density Polyethylene (HDPE untuk pembuatan tibial tray karena harganya yang lebih murah dan memiliki kemiripan sifat dengan UHMWPE. HDPE dibuat dengan dua metode, yaitu metode hot press dan pemanasan tanpa tekanan (PTT. UHMWPE dengan metode hot press digunakan sebagai pembanding. Metode hot press dilakukan pada suhu 180 °C dan diberi tekanan sebesar 200 kg/cm2. Sedangkan metode pemanasan tanpa tekanan (PTT dilakukan di dalam oven pada suhu 180°C. Film tipis UHMWPE dan sampel HDPE yang dihasilkan dari kedua metode tersebut, kemudian diiradiasi sinar gamma dengan variasi dosis 0, 100, 200, 300 dan 500 kGy. Karakterisasi mencakup analisis morfologi dengan Scanning Electron Microscope (SEM, uji kekerasan, kekuatan tarik, dan derajat kristalinitas. Semakin tinggi dosis radiasi, maka kekerasan dan derajat kristalinitas semakin meningkat, tetapi kekuatan tarik semakin menurun. Dosis radiasi untuk sampel HDPE yang optimum , adalah 100 kGy untuk HDPE yang dibuat dengan metoda hot press, pada kondisi ini HDPE mempunyai kekuatan mekanik mendekati nilai kekuatan mekanik UHMWPE, sedangkan HDPE yang dibuat dengan metode PTT kekuatan mekaniknya masih dibawah kekuatan mekanik HDPE yang dibuat dengan metoda hot press 

  17. Distribution of lithium in the Cordilleran Mantle wedge

    Science.gov (United States)

    Shervais, J. W.; Jean, M. M.; Seitz, H. M.

    2015-12-01

    Enriched fluid-mobile element (i.e., B, Li, Be) concentrations in peridotites from the Coast Range ophiolite are compelling evidence that this ophiolite originated in a subduction environment. A new method presented in Shervais and Jean (2012) for modeling the fluid enrichment process, represents the total addition of material to the mantle wedge source region and can be applied to any refractory mantle peridotite that has been modified by melt extraction and/or metasomatism. Although the end-result is attributed to an added flux of aqueous fluid or fluid-rich melt phase derived from the subducting slab, in the range of tens of parts per million - the nature and composition of this fluid could not be constrained. To address fluid(s) origins, we have analyzed Li isotopes in bulk rock peridotite and eclogite, and garnet separates, to identify possible sources, and fluid flow mechanisms and pathways. Bulk rock Li abundances of CRO peridotites (δ7Li = -14.3 to 5.5‰; 1.9-7.5 ppm) are indicative of Li addition and δ7Li-values are lighter than normal upper mantle values. However, Li abundances of clino- and orthopyroxene appear to record different processes operating during the CRO-mantle evolution. Low Li abundances in orthopyroxene (2 ppm) record subsequent interaction with Li-enriched fluids (or melts). The preferential partitioning of lithium in clinopyroxene could be indicative of a particular metasomatic agent, e.g., fluids from a dehydrating slab. Future in-situ peridotite isotope studies via laser ablation will further elucidate the fractionation of lithium between orthopyroxene, clinopyroxene, and serpentine. To obtain a more complete picture of the slab to arc transfer processes, we also measured eclogites and garnet separates to δ7Li= -18 to 3.5‰ (11.5-32.5 ppm) and δ7Li= 1.9 to 11.7‰ (0.7-3.9 ppm), respectively. In connection with previous studies focused on high-grade metamorphic assemblages within the Franciscan complex, an overall framework exists

  18. Using external and internal locking plates in a two-stage protocol for treatment of segmental tibial fractures.

    Science.gov (United States)

    Ma, Ching-Hou; Tu, Yuan-Kun; Yeh, Jih-Hsi; Yang, Shih-Chieh; Wu, Chin-Hsien

    2011-09-01

    The tibial segmental fractures usually follow high-energy trauma and are often associated with many complications. We designed a two-stage protocol for these complex injuries. The aim of this study was to assess the outcome of tibial segmental fractures treated according to this protocol. A prospective series of 25 consecutive segmental tibial fractures were treated using a two-stage procedure. In the first stage, a low-profile locking plate was applied as an external fixator to temporarily immobilize the fractures after anatomic reduction had been achieved followed by soft-tissue reconstruction. The second stage involved definitive internal fixation with a locking plate using a minimally invasive percutaneous plate osteosynthesis technique. The median follow-up was 32 months (range, 20-44 months). All fractures achieved union. The median time for the proximal fracture union was 23 weeks (range, 12-30 weeks) and that for distal fracture union was 27 weeks (range, 12-46 weeks; p = 0.08). Functional results were excellent in 21 patients and good in 4 patients. There were three cases of delayed union of distal fracture. Valgus malunion >5 degrees occurred in two patients, and length discrepancy >1 cm was observed in two patients. Pin tract infection occurred in three patients. Use of the two-stage procedure for treatment of segmental tibial fractures is recommended. Surgeons can achieve good reduction with stable temporary fixation, soft-tissue reconstruction, ease of subsequent definitive fixation, and high union rates. Our patients obtained excellent knee and ankle joint motion, good functional outcomes, and a comfortable clinical course.

  19. Distal tibial pilon fractures (AO/OTA type B, and C treated with the external skeletal and minimal internal fixation method

    Directory of Open Access Journals (Sweden)

    Milenković Saša

    2013-01-01

    Full Text Available Background/Aim. Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. Methods. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. Results. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60 years. The average follow-up was 21.86 (from 12 to 48 months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20 weeks. There were 4 (12.19% infections around the pins of the external skeletal fixator and one (3.22% deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90% patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. Conclusion. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for

  20. Distal tibial pilon fractures (AO/OTA type B, and C) treated with the external skeletal and minimal internal fixation method.

    Science.gov (United States)

    Milenković, Sasa; Mitković, Milorad; Micić, Ivan; Mladenović, Desimir; Najman, Stevo; Trajanović, Miroslav; Manić, Miodrag; Mitković, Milan

    2013-09-01

    Distal tibial pilon fractures include extra-articular fractures of the tibial metaphysis and the more severe intra-articular tibial pilon fractures. There is no universal method for treating distal tibial pilon fractures. These fractures are treated by means of open reduction, internal fixation (ORIF) and external skeletal fixation. The high rate of soft-tissue complications associated with primary ORIF of pilon fractures led to the use of external skeletal fixation, with limited internal fixation as an alternative technique for definitive management. The aim of this study was to estimate efficacy of distal tibial pilon fratures treatment using the external skeletal and minimal internal fixation method. We presented a series of 31 operated patients with tibial pilon fractures. The patients were operated on using the method of external skeletal fixation with a minimal internal fixation. According to the AO/OTA classification, 17 patients had type B fracture and 14 patients type C fractures. The rigid external skeletal fixation was transformed into a dynamic external skeletal fixation 6 weeks post-surgery. This retrospective study involved 31 patients with tibial pilon fractures, average age 41.81 (from 21 to 60) years. The average follow-up was 21.86 (from 12 to 48) months. The percentage of union was 90.32%, nonunion 3.22% and malunion 6.45%. The mean to fracture union was 14 (range 12-20) weeks. There were 4 (12.19%) infections around the pins of the external skeletal fixator and one (3.22%) deep infections. The ankle joint arthrosis as a late complication appeared in 4 (12.90%) patients. All arthroses appeared in patients who had type C fractures. The final functional results based on the AOFAS score were excellent in 51.61%, good in 32.25%, average in 12.90% and bad in 3.22% of the patients. External skeletal fixation and minimal internal fixation of distal tibial pilon fractures is a good method for treating all types of inta-articular pilon fractures. In

  1. A meta-analysis into the effect of lateral-wedged insoles with subtalar strapping versus traditional insoles in adults with medial knee osteoarthritis.

    Directory of Open Access Journals (Sweden)

    L. Duvenhage

    2011-02-01

    Full Text Available To  systematically  identify,  collate,  and  analyze  the  current available evidence  for  the  effectiveness  of  lateral-wedged  insoles,  with subtalar strapping,  on  reducing  pain,  improving  function  and  improving  the femoral-tibial  angle  (FTA,  in  adults  with  medial  knee osteoarthritis compared to traditional insoles without subtalar strapping.Six computerised databases, namely Cochrane Library, CiNAHL, PEDro, BIOMED central,  PubMed  and  ScienceDirect  were  searched. The  included articles were  then  all  rated  using  the  PEDro  scale  to  determine  their meth-odological quality.  Homogeneous data were pooled in a meta-analysis using Review Manager (REVMAN software.  Where statistical pooling of the results was not possible, findings were summarised in narrative form. Three randomised controlled trials were selected for this review. The average PEDro score was 5.7. A meta-analysis demonstrated that lateral-wedged insoles with subtalar strapping significantly reduced pain in the short-term (p=0.004. The review found that lateral-wedge insoles with subtalar strapping significantly decreased pain in the short-term and seemed to have a positive effect on the FTA in the long-term, when compared to traditional insoles without  subtalar strapping. The lateral-wedge insole with subtalar strapping may provide a financially feasible adjunctive self-management treatment for knee OA and should be considered before invasive procedures such as surgery.

  2. MR evaluation of femoral neck version and tibial torsion

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, James Karl; Dwek, Jerry R. [University of California, San Diego, Children' s Hospital and Health Center, Department of Radiology, San Diego, CA (United States); Pring, Maya E. [Rady Children' s Hospital, Department of Pediatric Orthopedic Surgery, San Diego, CA (United States)

    2012-01-15

    Abnormalities of femoral neck version have been associated with a number of hip abnormalities in children, including slipped capital femoral epiphysis, proximal femoral focal deficiency, coxa vara, a deep acetabulum and, rarely, developmental dysplasia of the hip. Orthopedic surgeons also are interested in quantifying the femoral neck anteversion or retroversion in children especially to plan derotational osteotomies. Historically, the angle of femoral version and tibial torsion has been measured with the use of radiography and later by CT. Both methods carry with them the risks associated with ionizing radiation. Techniques that utilize MR are used less often because of the associated lengthy imaging times. This article describes a technique using MRI to determine femoral neck version and tibial torsion with total scan times of approximately 10 min. (orig.)

  3. Adult tibial intercondylar eminence fracture: evaluation with MR imaging

    International Nuclear Information System (INIS)

    Toye, Leon R.; Cummings, Dean P.; Armendariz, Gus

    2002-01-01

    Tibial intercondylar eminence (TIE) fractures are well described in the pediatric orthopedic literature. Adult TIEs are much less common, and limited literature exists on the subject. Adult knee hyperextension injuries commonly result in anterior cruciate ligament (ACL) injury; however, with significant trauma, a TIE enters the differential diagnosis. Identification and classification of TIE fractures typically has been provided by radiography. The incidence of concomitant injuries with magnetic resonance (MR) imaging in patients with adult TIE fractures has not been determined. We present a case of an adult type III TIE fracture seen on radiography that only with further MR imaging revealed a concomitant lateral tibial plateau fracture. Utilization of MR imaging altered the surgeon's course of treatment and postoperative care. Radiographic and MR images and a review of the literature are provided. (orig.)

  4. Characterizing the Learning Effect in Response to Biofeedback Aimed at Reducing Tibial Acceleration during Running

    Directory of Open Access Journals (Sweden)

    Linda M. A. van Gelder

    2018-02-01

    Full Text Available Increased tibial acceleration has been found to be an important risk factor for tibial stress fractures. Interventions aimed at reducing this variable which found a beneficial effect include the use of biofeedback in gait retraining. However, no studies have focused on the time participants take to modify tibial acceleration, therefore we aimed to find the start of a learning plateau in this study. Six participants ran on a treadmill while multisensory feedback was given. A single-subject analysis was used to characterise the learning effects. All participants changed peak tibial acceleration within the first step of running in the feedback condition. Two participants further reduced tibial acceleration to reach a plateau within 120 steps. In four of the six participants a strong effect of the feedback was still present after a week. Further research is needed to optimise the use of biofeedback in reducing the prevalence of tibial stress fractures.

  5. Significant strain accumulation between the deformation front and landward out-of-sequence thrusts in accretionary wedge of SW Taiwan revealed by cGPS and SAR interferometry

    Science.gov (United States)

    Tsai, M. C.

    2017-12-01

    High strain accumulation across the fold-and-thrust belt in Southwestern Taiwan are revealed by the Continuous GPS (cGPS) and SAR interferometry. This high strain is generally accommodated by the major active structures in fold-and-thrust belt of western Foothills in SW Taiwan connected to the accretionary wedge in the incipient are-continent collision zone. The active structures across the high strain accumulation include the deformation front around the Tainan Tableland, the Hochiali, Hsiaokangshan, Fangshan and Chishan faults. Among these active structures, the deformation pattern revealed from cGPS and SAR interferometry suggest that the Fangshan transfer fault may be a left-lateral fault zone with thrust component accommodating the westward differential motion of thrust sheets on both side of the fault. In addition, the Chishan fault connected to the splay fault bordering the lower-slope and upper-slope of the accretionary wedge which could be the major seismogenic fault and an out-of-sequence thrust fault in SW Taiwan. The big earthquakes resulted from the reactivation of out-of-sequence thrusts have been observed along the Nankai accretionary wedge, thus the assessment of the major seismogenic structures by strain accumulation between the frontal décollement and out-of-sequence thrusts is a crucial topic. According to the background seismicity, the low seismicity and mid-crust to mantle events are observed inland and the lower- and upper- slope domain offshore SW Taiwan, which rheologically implies the upper crust of the accretionary wedge is more or less aseimic. This result may suggest that the excess fluid pressure from the accretionary wedge not only has significantly weakened the prism materials as well as major fault zone, but also makes the accretionary wedge landward extension, which is why the low seismicity is observed in SW Taiwan area. Key words: Continuous GPS, SAR interferometry, strain rate, out-of-sequence thrust.

  6. Tibial shaft fracture and ankle injury - Case report

    Directory of Open Access Journals (Sweden)

    Caio Zamboni

    Full Text Available ABSTRACT The authors report on a case of tibial shaft fracture associated with ankle injury. The clinical, radiological and surgical characteristics are discussed. Assessment of associated injuries is often overlooked and these injuries are hard to diagnose. When torque occurs in the lower limb, the ankle becomes susceptible to simultaneous injury. It is essential to make careful assessment based on clinical, radiographic, intraoperative and postoperative characteristics in order to attain functional recovery.

  7. Human tibial torsion - Morphometric assessment and clinical relevance

    Directory of Open Access Journals (Sweden)

    Swati Gandhi

    2014-02-01

    Full Text Available Background: Tibial torsion is an important anatomical parameter in clinical practice and displays variability among individuals. These variations are extremely significant in view of alignment guides such as those related to rotational landmarks of tibia in total knee arthroplasty. Further, precise knowledge and information pertaining to angle of tibial torsion also helps in correction of traumatic malunion or congenital maltorsion of tibia. Methods: The present study was carried out to determine the angle of tibial torsion in 100 adult dry tibia bones in the Department of Anatomy, Government Medical College, Amritsar. The study group comprised 50 males and 50 females with equal number of right- and left-sided bones. The measurements were meticulously recorded and the data were subjected to statistical analysis. The results were analyzed and discussed in the light of existing literature. Results: On the right side, it was found to be 29.84° ± 4.86°° (range = 22.00° -38.00° in males and 28.92° ± 5.10°° (range = 15.00°-38.00° in females. On the left side, it was found to be 28.00° ± 4.94°° (range = 20.00°-40.00°° in males and 28.12° ± 4.28°° (range = 20.00°-37.00°° in females. Conclusion: The present study is an endeavor to provide baseline data with reference to the angle of tibial torsion in the Indian population. The results of the study assume special importance in view of the technical advancements in reconstructive surgical procedures in orthopedic practice.

  8. Aetiology, imaging and treatment of medial tibial stress syndrome

    OpenAIRE

    Moen, M.H.

    2012-01-01

    The work contained is this thesis discusses aetiology, imaging and treatment of a common leg injury: medial tibial stress syndrome (MTSS). Although a common injury, the number of scientific articles on this topic is relatively low as is explained in chapter 1. This chapter also highlights that the most probable cause of MTSS is bone overload and not traction induced periostitis. In chapter 2 a review of the literature on MTSS is provided until 2009. Chapters 3 and 4 discuss different common a...

  9. Automated Mounting of Pole-Shoe Wedges in Linear Wave Power Generators—Using Industrial Robotics and Proximity Sensors

    Directory of Open Access Journals (Sweden)

    Tobias Kamf

    2017-03-01

    Full Text Available A system for automatic mounting of high tolerance wedges inside a wave power linear generator is proposed. As for any renewable energy concept utilising numerous smaller generation units, minimising the production cost per unit is vital for commercialization. The linear generator in question uses self-locking wedges, which are challenging to mount using industrial robots due to the high tolerances used, and because of the fact that any angular error remaining after calibration risks damaging the equipment. Using two types of probes, mechanical touch probes and inductive proximity sensors, combined with a flexible robot tool and iterative calibration routines, an automatic mounting system that overcomes the challenges of high tolerance wedge mounting is presented. The system is experimentally verified to work at mounting speeds of up to 50mm/s, and calibration accuracies of 0.25mmand 0.1 ∘ are achieved. The use of a flexible robot tool, able to move freely in one Cartesian plane, was found to be essential for making the system work.

  10. Degradation and stabilization of ice wedges: Implications for assessing risk of thermokarst in northern Alaska

    Science.gov (United States)

    Kanevskiy, Mikhail; Shur, Yuri; Jorgenson, Torre; Brown, Dana R. N.; Moskalenko, Nataliya; Brown, Jerry; Walker, Donald A.; Raynolds, Martha K.; Buchhorn, Marcel

    2017-11-01

    Widespread degradation of ice wedges has been observed during the last decades in numerous areas within the continuous permafrost zone of Eurasia and North America. To study ice-wedge degradation, we performed field investigations at Prudhoe Bay and Barrow in northern Alaska during 2011-2016. In each study area, a 250-m transect was established with plots representing different stages of ice-wedge degradation/stabilization. Field work included surveying ground- and water-surface elevations, thaw-depth measurements, permafrost coring, vegetation sampling, and ground-based LiDAR scanning. We described cryostratigraphy of frozen soils and stable isotope composition, analyzed environmental characteristics associated with ice-wedge degradation and stabilization, evaluated the vulnerability and resilience of ice wedges to climate change and disturbances, and developed new conceptual models of ice-wedge dynamics that identify the main factors affecting ice-wedge degradation and stabilization and the main stages of this quasi-cyclic process. We found significant differences in the patterns of ice-wedge degradation and stabilization between the two areas, and the patterns were more complex than those previously described because of the interactions of changing topography, water redistribution, and vegetation/soil responses that can interrupt or reinforce degradation. Degradation of ice wedges is usually triggered by an increase in the active-layer thickness during exceptionally warm and wet summers or as a result of flooding or disturbance. Vulnerability of ice wedges to thermokarst is controlled by the thickness of the intermediate layer of the upper permafrost, which overlies ice wedges and protects them from thawing. In the continuous permafrost zone, degradation of ice wedges rarely leads to their complete melting; and in most cases wedges eventually stabilize and can then resume growing, indicating a somewhat cyclic and reversible process. Stabilization of ice wedges

  11. [Balloon osteoplasty as reduction technique in the treatment of tibial head fractures].

    Science.gov (United States)

    Freude, T; Kraus, T M; Sandmann, G H

    2015-10-01

    Tibial plateau fractures requiring surgery are severe injuries of the lower extremities. Depending on the fracture pattern, the age of the patient, the range of activity and the bone quality there is a broad variation in adequate treatment.  This article reports on an innovative treatment concept to address split depression fractures (Schatzker type II) and depression fractures (Schatzker type III) of the tibial head using the balloon osteoplasty technique for fracture reduction. Using the balloon technique achieves a precise and safe fracture reduction. This internal osteoplasty combines a minimal invasive percutaneous approach with a gently rise of the depressed area and the associated protection of the stratum regenerativum below the articular cartilage surface. This article lights up the surgical procedure using the balloon technique in tibia depression fractures. Using the balloon technique a precise and safe fracture reduction can be achieved. This internal osteoplasty combines a minimally invasive percutaneous approach with a gentle raising of the depressed area and the associated protection of the regenerative layer below the articular cartilage surface. Fracture reduction by use of a tamper results in high peak forces over small areas, whereas by using the balloon the forces are distributed over a larger area causing less secondary stress to the cartilage tissue. This less invasive approach might help to achieve a better long-term outcome with decreased secondary osteoarthritis due to the precise and chondroprotective reduction technique.

  12. Ingenious method of external fixator use to maintain alignment for nailing a proximal tibial shaft fracture.

    Science.gov (United States)

    Behera, Prateek; Aggarwal, Sameer; Kumar, Vishal; Kumar Meena, Umesh; Saibaba, Balaji

    2015-09-01

    Fractures of the tibia are one of the most commonly seen orthopedic injuries. Most of them result from a high velocity trauma. While intramedullary nailing of tibial diaphyseal fractures is considered as the golden standard form of treatment for such cases, many metaphyseal and metaphyseal-diaphyseal junction fractures can also be managed by nailing. Maintenance of alignment of such fractures during surgical procedure is often challenging as the pull of patellar tendon tends to extend the proximal fragment as soon as one flexes the knee for the surgical procedure. Numerous technical modifications have been described in the literature for successfully nailing such fractures including semi extended nailing, use of medial plates and external fixators among others. In this study, it was aimed to report two cases in which we used our ingenious method of applying external fixator for maintaining alignment of the fracture and aiding in the entire process of closed intramedullary nailing of metaphyseal tibial fractures by the conventional method. We were able to get good alignment during and after the closed surgery as observed on post-operative radiographs and believe that further evaluation of this technique may be of help to surgeons who want to avoid other techniques.

  13. MRI in diagnostic of soft tissue damages by fractures of lateral tibial plate

    International Nuclear Information System (INIS)

    Dimitrova, D.; Proichev, V.; Popov, I.

    2015-01-01

    Full text: The knee is one of the most often injured joint. Fractures of tibial condyles are the most common articular damages. Koton and Berg call them „bumper“ fractures the tibia plateau is vulnerable to both high- and low-energy injury mechanisms due to its vulnerable position in the lower extremity. It must bear significant weight and sustain significant impact and deceleration forces with little skeletal constraint, and has scant surrounding soft tissue and a tethered medial and lateral integument. Furthermore, the tibial plateau has relatively forgiving ligamentous attachments that must allow for a large range of motion in a single plane. Not surprisingly, given the diversity of injury, management of these fractures has come to include a wide variety of treatment strategies. traditionally, ligament injury associated with plateau fractures has been diagnosed indirectly with stress radiographs and physical examination. With increasing use of more sensitive MRI and arthroscopy, associated ligament and meniscus injuries have been found in significant percentages of plateau fractures. these soft tissue injuries consist primarily of MCL lesions, meniscal injuries, and ACL disruptions. However, studies addressing associated soft tissue injuries all agree that neither the type of plateau fracture nor the presence or absence of ligament injury correlates with the incidence of meniscal tears

  14. A study to compare the motorised wedge output factor of an elekta synergy linear accelerator with reference data (TPS Data)

    International Nuclear Information System (INIS)

    Akosah, Kinsley

    2016-07-01

    For external beam radiotherapy treatments, high doses are delivered to the cancerous cell. Accuracy and precision of dose delivery are primary requirements for effective and efficient cancer treatment. The dose delivered to the patient might not be uniform and therefore need to be compensated for. In treatment these inhomogeneities are taken care of by using wedge filters and incorporating wedge factors in the Treatment Planning System. Computer controlled wedges were alternatives introduced by different manufacturers of which Motorized wedges (MW) is one of them. The MW was introduced by ELEKTA and this helps to overcome some of the shortcomings of physical wedges. The objectives of this study were to measure MW output factors for 6 MV and 15 MV photon energies for an ELEKTA Synergy. Secondly, to compare the results of MWOF obtained to that of the treatment planning system data. The Motorized Wedge Output Factors (MWOF) were measured for the ELEKTA Synergy for both 6 MV and 15 MV photon energies. With the help of PMMA solid water slabs phantom, the Elekta synergy, thermometer, barometer, PTW farmer type ionization chamber 30010 charges were collected at 100 cm source to surface distance for various square field sizes from 5x5 cm to 30x30 cm and depth of 1.5 cm and 2.5 cm for 6 MV and 15 MV photon energies. Comparing the results with the TPS data, an excellent agreement was found for 6 MV MWOF, with the percentage differences ranging from 0.03% to 1.50%, with a mean of 0.03%. The coefficient of variation of MWOF ranged from 0.023% to 1.07% and 0.001% to 12.89% for the two beams (6 MV and 15 MV) respectively. The relative differences between the calculated and the measured MWOFs increases with field size. In conclusion, there was general agreement between the calculated and measured MWOFs. The consistency of values provide further support that a standard dataset of photon and electron dosimetry could be established as a guide for future commissioning, beam modeling

  15. Effectiveness of various isometric exercises at improving bone strength in cortical regions prone to distal tibial stress fractures.

    Science.gov (United States)

    Florio, C S

    2018-06-01

    A computational model was used to compare the local bone strengthening effectiveness of various isometric exercises that may reduce the likelihood of distal tibial stress fractures. The developed model predicts local endosteal and periosteal cortical accretion and resorption based on relative local and global measures of the tibial stress state and its surface variation. Using a multisegment 3-dimensional leg model, tibia shape adaptations due to 33 combinations of hip, knee, and ankle joint angles and the direction of a single or sequential series of generated isometric resultant forces were predicted. The maximum stress at a common fracture-prone region in each optimized geometry was compared under likely stress fracture-inducing midstance jogging conditions. No direct correlations were found between stress reductions over an initially uniform circular hollow cylindrical geometry under these critical design conditions and the exercise-based sets of active muscles, joint angles, or individual muscle force and local stress magnitudes. Additionally, typically favorable increases in cross-sectional geometric measures did not guarantee stress decreases at these locations. Instead, tibial stress distributions under the exercise conditions best predicted strengthening ability. Exercises producing larger anterior distal stresses created optimized tibia shapes that better resisted the high midstance jogging bending stresses. Bent leg configurations generating anteriorly directed or inferiorly directed resultant forces created favorable adaptations. None of the studied loads produced by a straight leg was significantly advantageous. These predictions and the insight gained can provide preliminary guidance in the screening and development of targeted bone strengthening techniques for those susceptible to distal tibial stress fractures. Copyright © 2018 John Wiley & Sons, Ltd.

  16. Intramedullary nailing of proximal and distal one-third tibial shaft fractures with intraoperative two-pin external fixation.

    Science.gov (United States)

    Wysocki, Robert W; Kapotas, James S; Virkus, Walter W

    2009-04-01

    Fractures of the proximal and distal one thirds of the tibial shaft have historically higher malunion rates than those of the midshaft. This retrospective case series evaluates the postoperative radiographic outcome of intramedullary nailing of proximal and distal one-third tibial shaft fractures using intraoperative two-pin external fixation, often referred to as traveling traction. Between 2000 and 2005, 15 consecutive patients with proximal third and 27 consecutive patients with distal third displaced extra-articular fractures of the tibia were treated with statically locked intramedullary nailing and supplementary intraoperative two-pin rectangular frame external fixation. The external fixation was removed once the proximal and distal locking screws were in place. The alignment of the fractures was determined using standard postoperative anteroposterior and lateral radiographs. Postoperatively, 14 of 15 patients with proximal fractures and 25 of 27 patients with distal fractures had less than 5 degrees of angular deformity in both the coronal and sagittal planes and less than 1 cm shortening. Statically locked intramedullary nailing with simultaneous intraoperative traveling traction external fixation as treatment for proximal and distal one-third extra-articular tibial shaft fractures is successful in achieving a high rate of acceptable postoperative alignment.

  17. Comparison of suprapatellar and infrapatellar intramedullary nailing for tibial shaft fractures: a systematic review and meta-analysis.

    Science.gov (United States)

    Yang, Liqing; Sun, Yuefeng; Li, Ge

    2018-06-14

    Optimal surgical approach for tibial shaft fractures remains controversial. We perform a meta-analysis from randomized controlled trials (RCTs) to compare the clinical efficacy and prognosis between infrapatellar and suprapatellar intramedullary nail in the treatment of tibial shaft fractures. PubMed, OVID, Embase, ScienceDirect, and Web of Science were searched up to December 2017 for comparative RCTs involving infrapatellar and suprapatellar intramedullary nail in the treatment of tibial shaft fractures. Primary outcomes were blood loss, visual analog scale (VAS) score, range of motion, Lysholm knee scores, and fluoroscopy times. Secondary outcomes were length of hospital stay and postoperative complications. We assessed statistical heterogeneity for each outcome with the use of a standard χ 2 test and the I 2 statistic. The meta-analysis was undertaken using Stata 14.0. Four RCTs involving 293 participants were included in our study. The present meta-analysis indicated that there were significant differences between infrapatellar and suprapatellar intramedullary nail regarding the total blood loss, VAS scores, Lysholm knee scores, and fluoroscopy times. Suprapatellar intramedullary nailing could significantly reduce total blood loss, postoperative knee pain, and fluoroscopy times compared to infrapatellar approach. Additionally, it was associated with an improved Lysholm knee scores. High-quality RCTs were still required for further investigation.

  18. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  19. 75% success rate after open debridement, exchange of tibial insert, and antibiotics in knee prosthetic joint infections.

    Science.gov (United States)

    Holmberg, Anna; Thórhallsdóttir, Valdís Gudrún; Robertsson, Otto; W-Dahl, Annette; Stefánsdóttir, Anna

    2015-01-01

    Prosthetic joint infection (PJI) is a leading cause of early revision after total knee arthroplasty (TKA). Open debridement with exchange of tibial insert allows treatment of infection with retention of fixed components. We investigated the success rate of this procedure in the treatment of knee PJIs in a nationwide material, and determined whether the results were affected by microbiology, antibiotic treatment, or timing of debridement. 145 primary TKAs revised for the first time, due to infection, with debridement and exchange of the tibial insert were identified in the Swedish Knee Arthroplasty Register (SKAR). Staphylococcus aureus was the most common pathogen (37%) followed by coagulase-negative staphylococci (CNS) (23%). Failure was defined as death before the end of antibiotic treatment, revision of major components due to infection, life-long antibiotic treatment, or chronic infection. The overall healing rate was 75%. The type of infecting pathogen did not statistically significantly affect outcome. Staphylococcal infections treated without a combination of antibiotics including rifampin had a higher failure rate than those treated with rifampin (RR = 4, 95% CI: 2-10). In the 16 cases with more than 3 weeks of symptoms before treatment, the healing rate was 62%, as compared to 77% in the other cases (p = 0.2). The few patients with a revision model of prosthesis at primary operation had a high failure rate (5 of 8). Good results can be achieved by open debridement with exchange of tibial insert. It is important to use an antibiotic combination including rifampin in staphylococcal infections.

  20. Aneurisma verdadeiro bilateral de artéria tibial posterior True bilateral aneurysm of the posterior tibial artery

    Directory of Open Access Journals (Sweden)

    Silvio Romero de Barros Marques

    2006-03-01

    Full Text Available Neste artigo, faz-se o relato de um caso de aneurisma verdadeiro bilateral da artéria tibial posterior em paciente de 57 anos. Os aneurismas surgiram em épocas diferentes. Os aspectos clínicos, diagnósticos e terapêuticos deste caso são discutidos. Este relato é importante, pois os autores não têm conhecimento de caso semelhante na literatura consultada.This article reports a case of true bilateral aneurysm of the tibial posterior artery in a 57 year-old patient. The aneurysms occurred at different times. The clinical, diagnostic and therapeutic aspects of this case are discussed. This report is important because the authors did not find a similar description in the literature.

  1. Tibial rotational osteotomy for idiopathic torsion. A comparison of the proximal and distal osteotomy levels.

    Science.gov (United States)

    Krengel, W F; Staheli, L T

    1992-10-01

    A retrospective analysis was done of 52 rotational tibial osteotomies (RTOs) performed on 35 patients with severe idiopathic tibial torsion. Thirty-nine osteotomies were performed at the proximal or midtibial level. Thirteen were performed at the distal tibial level with a technique previously described by one of the authors. Serious complications occurred in five (13%) of the proximal and in none of the distal RTOs. For severe and persisting idiopathic tibial torsion, the authors recommend correction by RTO at the distal level. Proximal level osteotomy is indicated only when a varus or valgus deformity required concurrent correction.

  2. Arthroscopic treatment of displaced tibial eminence fractures using a suspensory fixation

    Directory of Open Access Journals (Sweden)

    Philippe Loriaut

    2017-01-01

    Conclusion: The arthroscopic treatment of displaced tibial intercondylar eminence fractures using a suspensory system provided a satisfactory clinical and radiological outcome at a followup of 2 years.

  3. The Tibial Slope in Patients With Achondroplasia: Its Characterization and Possible Role in Genu Recurvatum Development.

    Science.gov (United States)

    Brooks, Jaysson T; Bernholt, David L; Tran, Kevin V; Ain, Michael C

    2016-06-01

    Genu recurvatum, a posterior resting position of the knee, is a common lower extremity deformity in patients with achondroplasia and has been thought to be secondary to ligamentous laxity. To the best of our knowledge, the role of the tibial slope has not been investigated, and no studies describe the tibial slope in patients with achondroplasia. Our goals were to characterize the tibial slope in children and adults with achondroplasia, explore its possible role in the development of genu recurvatum, and compare the tibial slope in patients with achondroplasia to that in the general population. We reviewed 252 lateral knee radiographs of 130 patients with achondroplasia seen at our clinic from November 2007 through September 2013. Patients were excluded if they had previous lower extremity surgery or radiographs with extreme rotation. We analyzed patient demographics and, on all radiographs, the tibial slope. We then compared the mean tibial slope to norms in the literature. Tibial slopes >90 degrees had an anterior tibial slope and received a positive prefix. Statistical analysis included intraclass and interclass reliability, Pearson correlation coefficient, and the Student t tests (significance, Pachondroplasia than in the general population; however, this difference diminishes as patients' age. An anterior tibial slope may predispose to a more posterior resting knee position, also known as genu recurvatum. Level IV-retrospective case series.

  4. Preoperative Measurement of Tibial Resection in Total Knee Arthroplasty Improves Accuracy of Postoperative Limb Alignment Restoration

    Directory of Open Access Journals (Sweden)

    Pei-Hui Wu

    2016-01-01

    Conclusions: Using conventional surgical instruments, preoperative measurement of resection thickness of the tibial plateau on radiographs could improve the accuracy of conventional surgical techniques.

  5. Effect of tibial slope on the stability of the anterior cruciate ligament-deficient knee.

    Science.gov (United States)

    Voos, James E; Suero, Eduardo M; Citak, Musa; Petrigliano, Frank P; Bosscher, Marianne R F; Citak, Mustafa; Wickiewicz, Thomas L; Pearle, Andrew D

    2012-08-01

    We aimed to quantify the effect of changes in tibial slope on the magnitude of anterior tibial translation (ATT) in the anterior cruciate ligament (ACL)-deficient knee during the Lachman and mechanized pivot shift tests. We hypothesized that increased posterior tibial slope would increase the amount of ATT of an ACL-deficient knee, while leveling the slope of the tibial plateau would decrease the amount of ATT. Lachman and mechanized pivot shift tests were performed on hip-to-toe cadaveric specimens, and ATT of the lateral and the medial compartments was measured using navigation (n = 11). The ACL was then sectioned. Stability testing was repeated, and ATT was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5 or -5° of tibial slope variation after which stability testing was repeated (n = 10). Sectioning the ACL resulted in a significant increase in ATT in both the Lachman and mechanized pivot shift tests (P slope of the tibial plateau had no effect on ATT during the Lachman test (n.s.). During the mechanized pivot shift tests, a 5° increase in posterior slope resulted in a significant increase in ATT compared to the native knee (P slope reduced ATT to a level similar to that of the intact knee. Tibial slope changes did not affect the magnitude of translation during a Lachman test. However, large changes in tibial slope variation affected the magnitude of the pivot shift.

  6. Sandbox rheometry: Co-evolution of stress and strain in Riedel- and Critical Wedge-experiments

    Science.gov (United States)

    Ritter, Malte C.; Santimano, Tasca; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2018-01-01

    Analogue sandbox experiments have been used for a long time to understand tectonic processes, because they facilitate detailed measurements of deformation at a spatio-temporal resolution unachievable from natural data. Despite this long history, force measurements to further characterise the mechanical evolution in analogue sandbox experiments have only emerged recently. Combined continuous measurements of forces and deformation in such experiments, an approach here referred to as "sandbox rheometry", are a new tool that may help to better understand work budgets and force balances for tectonic systems and to derive constitutive laws for regional scale deformation. In this article we present an experimental device that facilitates precise measurements of boundary forces and surface deformation at high temporal and spatial resolution. We demonstrate its capabilities in two classical experiments: one of strike-slip deformation (the Riedel set-up) and one of compressional accretionary deformation (the Critical Wedge set-up). In these we are able to directly observe a correlation between strain weakening and strain localisation that had previously only been inferred, namely the coincidence of the maximum localisation rate with the onset of weakening. Additionally, we observe in the compressional experiment a hysteresis of localisation with respect to the mechanical evolution that reflects the internal structural complexity of an accretionary wedge.

  7. Ingestion of plastic debris by Laysan albatrosses and wedge-tailed shearwaters in the Hawaiian Islands

    Science.gov (United States)

    Fry, D.M.; Fefer, S.I.; Sileo, L.

    1987-01-01

    Surveys of Laysan Albatross and Wedge-tailed Shearwaters on Midway and Oahu Island, Hawaii, identified a high proportion of birds with plastic in the upper gastrointestinal tract, representing hazards to the health of adult birds and their chicks. Fifty Laysan Albatross chicks were examined for plastic items lodged within the upper digestive tract. Forty-five (90%) contained plastic, including 3 chicks having proventricular impactions or ulcerative lesions. Plastic items in 21 live albatross chicks weighed a mean of 35.7 g chicka??1 (range 1a??175 g). Four dead birds contained 14a??175 g (mean 76.7 g). Two of four adult albatross examined contained plastic in the gut. Laysan albatross chicks have the highest reported incidence and amount of ingested plastic of any seabird species. Twelve of 20 adult Wedge-tailed Shearwaters (60%) contained plastic particles 2a??4 mm in diameter. Impaction did not appear to be a significant hazard for adult shearwaters. Shearwater chicks were not examined. Chemical toxicity of plastic polymers, plasticizers and antioxidant additives is low, although many pigments are toxic and plastics may serve as vehicles for the adsorption of organochlorine pollutants from sea water, and the toxicity of plastics is unlikely to pose significant hazard compared to obstruction and impaction of the gut.

  8. Enhanced performance of fast-response 3-hole wedge probes for transonic flows in axial turbomachinery

    Energy Technology Data Exchange (ETDEWEB)

    Delhaye, D.; Paniagua, G. [von Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Fernandez Oro, J.M. [Universidad de Oviedo, Area de Mecanica de Fluidos, Gijon (Spain); Denos, R. [European Commission, Directorate General for Research, Brussels (Belgium)

    2011-01-15

    The paper presents the development and application of a three-sensor wedge probe to measure unsteady aerodynamics in a transonic turbine. CFD has been used to perform a detailed uncertainty analysis related to probe-induced perturbations, in particular the separation zones appearing on the wedge apex. The effects of the Reynolds and Mach numbers are studied using both experimental data together with CFD simulations. The angular range of the probe and linearity of the calibration maps are enhanced with a novel zonal calibration technique, used for the first time in compressible flows. The data reduction methodology is explained and demonstrated with measurements performed in a single-stage high-pressure turbine mounted in the compression tube facility of the von Karman Institute. The turbine was operated at subsonic and transonic pressure ratios (2.4 and 5.1) for a Reynolds number of 10{sup 6}, representative of modern engine conditions. Complete maps of the unsteady flow angle and rotor outlet Mach number are documented. These data allow the study of secondary flows and rotor trailing edge shocks. (orig.)

  9. Microtopographic control on the ground thermal regime in ice wedge polygons

    Science.gov (United States)

    Abolt, Charles J.; Young, Michael H.; Atchley, Adam L.; Harp, Dylan R.

    2018-06-01

    The goal of this research is to constrain the influence of ice wedge polygon microtopography on near-surface ground temperatures. Ice wedge polygon microtopography is prone to rapid deformation in a changing climate, and cracking in the ice wedge depends on thermal conditions at the top of the permafrost; therefore, feedbacks between microtopography and ground temperature can shed light on the potential for future ice wedge cracking in the Arctic. We first report on a year of sub-daily ground temperature observations at 5 depths and 9 locations throughout a cluster of low-centered polygons near Prudhoe Bay, Alaska, and demonstrate that the rims become the coldest zone of the polygon during winter, due to thinner snowpack. We then calibrate a polygon-scale numerical model of coupled thermal and hydrologic processes against this dataset, achieving an RMSE of less than 1.1 °C between observed and simulated ground temperature. Finally, we conduct a sensitivity analysis of the model by systematically manipulating the height of the rims and the depth of the troughs and tracking the effects on ice wedge temperature. The results indicate that winter temperatures in the ice wedge are sensitive to both rim height and trough depth, but more sensitive to rim height. Rims act as preferential outlets of subsurface heat; increasing rim size decreases winter temperatures in the ice wedge. Deeper troughs lead to increased snow entrapment, promoting insulation of the ice wedge. The potential for ice wedge cracking is therefore reduced if rims are destroyed or if troughs subside, due to warmer conditions in the ice wedge. These findings can help explain the origins of secondary ice wedges in modern and ancient polygons. The findings also imply that the potential for re-establishing rims in modern thermokarst-affected terrain will be limited by reduced cracking activity in the ice wedges, even if regional air temperatures stabilize.

  10. Long-term complications following tibial plateau levelling osteotomy in small dogs with tibial plateau angles > 30°.

    Science.gov (United States)

    Knight, Rebekah; Danielski, Alan

    2018-04-21

    Tibial plateau levelling osteotomy (TPLO) is commonly performed for surgical management of cranial cruciate ligament (CCL) disease. It has been suggested that small dogs may have steeper tibial plateau angles (TPAs) than large dogs, which has been associated with increased complication rates after TPLO. A retrospective study was performed to assess the rate and nature of long-term complications following TPLO in small dogs with TPAs>30°. Medical records were reviewed for dogs with TPAs>30° treated for CCL rupture by TPLO with a 2.0 mm plate over a five-year period. Radiographs were assessed to determine TPA, postoperative tibial tuberosity width and to identify any complication. Up-to-date medical records were obtained from the referring veterinary surgeon and any complications in the year after surgery were recorded. The effects of different variables on complication rate were assessed using logistic regression analysis. Minor complications were reported in 22.7 per cent of cases. This is similar to or lower than previously reported complication rates for osteotomy techniques in small dogs and dogs with steep TPAs. A smaller postoperative TPA was the only variable significantly associated with an increased complication rate. No major complications were identified. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Modes of continental extension in a crustal wedge

    KAUST Repository

    Wu, Guangliang

    2015-07-01

    © 2015 Elsevier B.V. We ran numerical experiments of the extension of a crustal wedge as an approximation to extension in an orogenic belt or a continental margin. We study the effects of the strength of the lower crust and of a weak mid-crustal shear zone on the resulting extension styles. A weak mid-crustal shear zone effectively decouples upper crustal extension from lower crustal flow. Without the mid-crustal shear zone, the degree of coupling between the upper and the lower crust increases and extension of the whole crust tends to focus on the thickest part of the wedge. We identify three distinct modes of extension determined by the strength of the lower crust, which are characterized by 1) localized, asymmetric crustal exhumation in a single massif when the lower crust is weak, 2) the formation of rolling-hinge normal faults and the exhumation of lower crust in multiple core complexes with an intermediate strength lower crust, and 3) distributed domino faulting over the weak mid-crustal shear zone when the lower crust is strong. A frictionally stronger mid-crustal shear zone does not change the overall model behaviors but extension occurred over multiple rolling-hinges. The 3 modes of extension share characteristics similar to geological models proposed to explain the formation of metamorphic core complexes: 1) the crustal flow model for the weak lower crust, 2) the rolling-hinge and crustal flow models when the lower crust is intermediate and 3) the flexural uplift model when the lower crust is strong. Finally we show that the intensity of decoupling between the far field extension and lower crustal flow driven by the regional pressure gradient in the wedge control the overall style of extension in the models.

  12. Modes of continental extension in a crustal wedge

    KAUST Repository

    Wu, Guangliang; Lavier, Luc L.; Choi, Eunseo

    2015-01-01

    © 2015 Elsevier B.V. We ran numerical experiments of the extension of a crustal wedge as an approximation to extension in an orogenic belt or a continental margin. We study the effects of the strength of the lower crust and of a weak mid-crustal shear zone on the resulting extension styles. A weak mid-crustal shear zone effectively decouples upper crustal extension from lower crustal flow. Without the mid-crustal shear zone, the degree of coupling between the upper and the lower crust increases and extension of the whole crust tends to focus on the thickest part of the wedge. We identify three distinct modes of extension determined by the strength of the lower crust, which are characterized by 1) localized, asymmetric crustal exhumation in a single massif when the lower crust is weak, 2) the formation of rolling-hinge normal faults and the exhumation of lower crust in multiple core complexes with an intermediate strength lower crust, and 3) distributed domino faulting over the weak mid-crustal shear zone when the lower crust is strong. A frictionally stronger mid-crustal shear zone does not change the overall model behaviors but extension occurred over multiple rolling-hinges. The 3 modes of extension share characteristics similar to geological models proposed to explain the formation of metamorphic core complexes: 1) the crustal flow model for the weak lower crust, 2) the rolling-hinge and crustal flow models when the lower crust is intermediate and 3) the flexural uplift model when the lower crust is strong. Finally we show that the intensity of decoupling between the far field extension and lower crustal flow driven by the regional pressure gradient in the wedge control the overall style of extension in the models.

  13. Heat conduction problem of an evaporating liquid wedge

    Directory of Open Access Journals (Sweden)

    Tomas Barta

    2015-02-01

    Full Text Available We consider the stationary heat transfer near the contact line of an evaporating liquid wedge surrounded by the atmosphere of its pure vapor. In a simplified setting, the problem reduces to the Laplace equation in a half circle, subject to a non-homogeneous and singular boundary condition. By classical tools (conformal mapping, Green's function, we reformulate the problem as an integral equation for the unknown Neumann boundary condition in the setting of appropriate fractional Sobolev and weighted space. The unique solvability is then obtained by means of the Fredholm theorem.

  14. Comparison between angiographic and arterial duplex ultrasound assessment of tibial arteries in patients with peripheral arterial disease: on behalf of the Joint Endovascular and Non-Invasive Assessment of LImb Perfusion (JENALI) Group.

    Science.gov (United States)

    Mustapha, Jihad A; Saab, Fadi; Diaz-Sandoval, Larry; Karenko, Barbara; McGoff, Theresa; Heaney, Carmen; Sevensma, Matthew

    2013-11-01

    peroneal artery. The angiographic and ultrasound JENALI scores better correlated with vessel patency (higher scores) than the lower angiographic and ultrasound JENALI scores. Using the novel JENALI scoring system allowed for direct comparison between two imaging modalities. In theory, the comparison can be extended to other imaging modalities. Ultrasound imaging had a high sensitivity in detecting patent vessels confirmed by angiography. Detecting occluded segments via ultrasound was less accurate. The highest accuracy was in the more superficial arteries (ie, anterior tibial, posterior tibial), compared to the deeper peroneal arteries. Risk stratification, treatment, and patient outcomes may be future applications of the JENALI scoring system.

  15. Mediolateral Differences of Proteoglycans Distribution at the ACL Tibial Footprint: Experimental Study of 16 Cadaveric Knees

    Directory of Open Access Journals (Sweden)

    Joon Ho Wang

    2018-01-01

    Full Text Available This study aimed to identify the staining pattern of ACL attachment blended with cartilage of the medial tibial plateau at the tibial insertion and histologically characterize the tibial footprint. Sixteen fresh frozen cadaveric knees (mean age: 52.0±6.2 years were used for this study. The specimens were bisected in the coronal plane, in accordance with the fiber orientation of the ACL tibial attachment. Adjacent sections were then stained with hematoxylin and eosin (H&E to observe the morphology of the ACL insertion and with fast green and Safranin-O protocols to evaluate for collagen and proteoglycans (PG. The insertion area on the tibial footprint was divided into five zones in the medial to lateral direction, which was determined by division of the section from most prominent medial tibial spine to most lateral margin of ACL attachment. Then rectangular area with a vertical length that is twice the width of respective five zones was set. Stained areas of all images were quantified positively by using ImageJ software, and the value for staining area measured was defined in percentage by multiplying whole image area by 100. The mean proportion of Safranin-O staining is significantly greater nearer to the medial tibial spine (59% in zone 1, 32% in zone 2, 13% in zone 3, 13% in zone 4, and 4% in zone 5, P<0.001. The medial section of the tibial insertion area grew in size and increased in PG staining with more densely organized collagen arrangement with more fibrocartilage cells. The ACL tibial insertion showed a medially eccentric staining pattern by histological evaluation of the ACL attachment to cartilage. Our histological results of the eccentric biomaterial property in the medial tibial spine of ACL insertion area can be considered in making a more functional anatomic tibial tunnel placement.

  16. Near-Surface Profiles of Water Stable Isotope Components and Indicated Transitional History of Ice-Wedge Polygons Near Barrow

    Science.gov (United States)

    Iwahana, G.; Wilson, C.; Newman, B. D.; Heikoop, J. M.; Busey, R.

    2017-12-01

    Wetlands associated with ice-wedge polygons are commonly distributed across the Arctic Coastal Plain of northern Alaska, a region underlain by continuous permafrost. Micro-topography of the ice-wedge polygons controls local hydrology, and the micro-topography could be altered due to factors such like surface vegetation, wetness, freeze-thaw cycles, and permafrost degradation/aggradation under climate change. Understanding status of the wetlands in the near future is important because it determines biogeochemical cycle, which drives release of greenhouse gases from the ground. However, transitional regime of the ice-wedge polygons under the changing climate is not fully understood. In this study, we analyzed geochemistry of water extracted from frozen soil cores sampled down to about 1m depth in 2014 March at NGEE-Arctic sites in the Barrow Environmental Observatory. The cores were sampled from troughs/rims/centers of five different low-centered or flat-centered polygons. The frozen cores are divided into 5-10cm cores for each location, thawed in sealed plastic bags, and then extracted water was stored in vials. Comparison between the profiles of geochemistry indicated connection of soil water in the active layer at different location in a polygon, while it revealed that distinctly different water has been stored in permafrost layer at troughs/rims/centers of some polygons. Profiles of volumetric water content (VWC) showed clear signals of freeze-up desiccation in the middle of saturated active layers as low VWC anomalies at most sampling points. Water in the active layer and near-surface permafrost was classified into four categories: ice wedge / fresh meteoric / transitional / highly fractionated water. The overall results suggested prolonged separation of water in the active layer at the center of low-centered polygons without lateral connection in water path in the past.

  17. Quadriceps force and anterior tibial force occur obviously later than vertical ground reaction force: a simulation study

    OpenAIRE

    Ueno, Ryo; Ishida, Tomoya; Yamanaka, Masanori; Taniguchi, Shohei; Ikuta, Ryohei; Samukawa, Mina; Saito, Hiroshi; Tohyama, Harukazu

    2017-01-01

    Background: Although it is well known that quadriceps force generates anterior tibial force, it has been unclear whether quadriceps force causes great anterior tibial force during the early phase of a landing task. The purpose of the present study was to examine whether the quadriceps force induced great anterior tibial force during the early phase of a landing task. Methods: Fourteen young, healthy, female subjects performed a single-leg landing task. Muscle force and anterior tibial force w...

  18. The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining TKA

    NARCIS (Netherlands)

    Marra, Marco A.; Strzelczak, Marta; Heesterbeek, Petra J.C.; van de Groes, Sebastiaan; Janssen, Dennis; Koopman, Bart F.J.M.; Wymenga, Ate B.; Verdonschot, Nico

    2017-01-01

    INTRODUCTION: Tibial slope can affect the outcomes of Total Knee Arthroplasty (TKA). More posterior slope potentially helps releasing a too tight flexion gap and it is generally associated with a wider range of post-operative knee flexion. However, the mechanism by which tibial slope affects the

  19. Negative pressure wound therapy for Gustilo Anderson grade IIIb open tibial fractures

    Directory of Open Access Journals (Sweden)

    Chul Hyun Park

    2016-01-01

    Conclusion: Staged treatment using NPWT decreased the risks of infection and requirement of flap surgeries in Gustilo Anderson grade IIIb open tibial fractures. Therefore, staged treatment using NPWT could be a useful treatment option for Gustilo Anderson grade IIIb open tibial fractures.

  20. Metachronous Bilateral Posterior Tibial Artery Aneurysms in Ehlers-Danlos Syndrome Type IV

    International Nuclear Information System (INIS)

    Hagspiel, Klaus D.; Bonatti, Hugo; Sabri, Saher; Arslan, Bulent; Harthun, Nancy L.

    2011-01-01

    Ehlers-Danlos syndrome type IV is a life-threatening genetic connective tissue disorder. We report a 24-year-old woman with EDS-IV who presented with metachronous bilateral aneurysms/pseudoaneurysms of the posterior tibial arteries 15 months apart. Both were treated successfully with transarterial coil embolization from a distal posterior tibial approach.

  1. Management of open tibial fractures – a regional experience

    Science.gov (United States)

    Townley, WA; Nguyen, DQA; Rooker, JC; Dickson, JK; Goroszeniuk, DZ; Khan, MS; Camp, D

    2010-01-01

    INTRODUCTION The treatment of soft-tissue injuries associated with tibial diaphyseal fractures presents a clinical challenge that is best managed by a combined plastic and orthopaedic surgery approach. The current study was undertaken to assess early treatment outcomes and burden of service provision across five regional plastic surgery units in the South-West of England. SUBJECTS AND METHODS We conducted a prospective 6-month audit of open tibial diaphyseal fracture management in five plastic surgery units (Bristol, Exeter, Plymouth, Salisbury, Swansea) with a collective catchment of 9.2 million people. Detailed data were collected on patient demographics, injury pattern, surgical management and outcome followed to discharge. RESULTS The study group consisted of 55 patients (40 male, 15 female). Twenty-two patients presented directly to the emergency department at the specialist hospital (primary group), 33 patients were initially managed at a local hospital (tertiary group). The mean time from injury to soft tissue cover was significantly less (P < 0.001) in the primary group (3.6 ± 0.8 days) than the tertiary group (10.8 ± 2.2 days), principally due to a delay in referral in the latter group (5.4 ±1.7 days). Cover was achieved with 39 flaps (19 free, 20 local), eight split skin grafts. Nine wounds closed directly or by secondary intention. There were 11 early complications (20%) including one flap failure and four infections. The overall mean length of stay was 17.5 ± 2.8 days. CONCLUSIONS Multidisciplinary management of severe open tibial diaphyseal may not be feasible at presentation of injury depending on local hospital specialist services available. Our results highlight the need for robust assessment, triage and senior orthopaedic review in the early post-injury phase. However, broader improvements in the management of lower limb trauma will additionally require further development of combined specialist trauma centres. PMID:21047449

  2. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  3. Fracture reduction and primary ankle arthrodesis: a reliable approach for severely comminuted tibial pilon fracture.

    Science.gov (United States)

    Beaman, Douglas N; Gellman, Richard

    2014-12-01

    Posttraumatic arthritis and prolonged recovery are typical after a severely comminuted tibial pilon fracture, and ankle arthrodesis is a common salvage procedure. However, few reports discuss the option of immediate arthrodesis, which may be a potentially viable approach to accelerate overall recovery in patients with severe fracture patterns. (1) How long does it take the fracture to heal and the arthrodesis to fuse when primary ankle arthrodesis is a component of initial fracture management? (2) How do these patients fare clinically in terms of modified American Orthopaedic Foot and Ankle Society (AOFAS) scores and activity levels after this treatment? (3) Does primary ankle arthrodesis heal in an acceptable position when anterior ankle arthrodesis plates are used? During a 2-year period, we performed open fracture reduction and internal fixation in 63 patients. Eleven patients (12 ankles) with severely comminuted high-energy tibial pilon fractures were retrospectively reviewed after surgical treatment with primary ankle arthrodesis and fracture reduction. Average patient age was 58 years, and minimum followup was 6 months (average, 14 months; range, 6-22 months). Anatomically designed anterior ankle arthrodesis plates were used in 10 ankles. Ring external fixation was used in nine ankles with concomitant tibia fracture or in instances requiring additional fixation. Clinical evaluation included chart review, interview, the AOFAS ankle-hindfoot score, and radiographic evaluation. All of the ankle arthrodeses healed at an average of 4.4 months (range, 3-5 months). One patient had a nonunion at the metaphyseal fracture, which healed with revision surgery. The average AOFAS ankle-hindfoot score was 83 with 88% having an excellent or good result. Radiographic and clinical analysis confirmed a plantigrade foot without malalignment. No patients required revision surgery for malunion. Primary ankle arthrodesis combined with fracture reduction for the severely comminuted

  4. Outcomes of The Isolated Closed Tibial Shaft Fractures Treated Nonsurgically

    Directory of Open Access Journals (Sweden)

    Dawood Jafari

    2011-05-01

    Full Text Available Background: Fractures of the tibia are important for their commonness and controversy in their management. Both conservative and surgical techniques have been introduced in an effort to speed time to union while minimizing the occurrence of complications. Standard treatment for low-energy tibial shaft fractures includes closed reduction and cast immobilization.The purpose of our study was to analyze retention of reduction after cast immobilization of simple isolated closed tibial fractures.Methods:All cases of the diagnosed isolated closed tibial shaft fracture treated non-surgically at Shafa Yahyaeian Hospital, between 2006 and 2009 were retrieved from medical records. We reviewed all medical records and radiographs of these patients to inquire about the patients’ demographic data used to analyze the outcomes of the non-surgical treatment.Results:Of the 26 patients examined, males were more commonly affected. The mean age was 27.46   (SD=7.58.The most common causes of injury were direct blow and motorcycle to pedestrian accident. Followup duration for each patient had an average of 9.12 months (SD=2.36. Using AO/OTA classification, distributed as 38.5% A1.1, 26.9% A2.1 and 34.6% A3.1 fractures. Most fractures were sustained in the lower third of the tibia (53.85%. All fractures eventually healed in an average of 13.7 weeks (SD=3.24. There was one case of delayed union in the 22nd week. In 92.3% of patients, shortening of bone was less than 1 cm, while in 7.7% patients, was more than 1.5 cm. We observed an anterior or posterior angulation > 10 ° in 2 (7.69% patients. Moreover, in 4 (15.38% patients we found varus angulation > 5°. Therefore, final deformity was observed in 8 (30.77% patients. No patient had non-union, rotational malalignment of more than 10 degrees, an infection, or a compartment syndrome.Conclusion : Our non-surgical treatment’s outcomes were not satisfactory, despite applying all principles for conservative treatment and

  5. Tibial tunnel and pretibial cysts following ACL graft reconstruction: MR imaging diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Ghazikhanian, Varand [Brigham and Women' s Hospital, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Beltran, Javier [Maimonides Medical Center, Brooklyn, NY (United States); Nikac, Violeta [Maimonides Medical Center, Department of Radiology, Brooklyn, NY (United States); Bencardino, Jenny T. [NYU Hospital for Joint Diseases, New York, NY (United States); Feldman, Marina

    2012-11-15

    Tunnel cyst formation is a rare complication after anterior cruciate ligament reconstruction, usually occurring 1-5 years post-operatively, which may occasionally be symptomatic. There are multiple proposed theories regarding the etiology of tunnel cysts. Theories include necrosis, foreign-body reaction, lack of complete graft osteo-integration, and intravasation of articular fluid. It is important to know if the tunnel cysts are communicating or not communicating with the joint, as surgical management may be different. Imaging characteristics on magnetic resonance images (MRI) include tibial tunnel widening, multilocular or unilocular cyst formation in the graft or tibial tunnel, with possible extension into the pretibial space, intercondylar notch, and/or popliteal fossa. The MR imaging differential diagnosis of tibial tunnel cysts includes infection, foreign-body granuloma, or tibial screw extrusion. Importantly, to the best of our knowledge, graft failure or instability has not been reported in association with tibial tunnel cysts. (orig.)

  6. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player

    Directory of Open Access Journals (Sweden)

    Ichiro Tonogai

    2017-01-01

    Full Text Available Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy.

  7. Generalized monitor unit calculation for the Varian enhanced dynamic wedge field

    International Nuclear Information System (INIS)

    Liu Chihray; Kim, Siyong; Kahler, Darren L.; Palta, Jatinder R.

    2003-01-01

    The generalized monitor unit (MU) calculation equation for the Varian enhanced dynamic wedge (EDW) is derived. The assumption of this MU calculation method is that the wedge factor of the EDW at the center of the field is a function of field size, the position of the center of the field in the wedge direction, and the final position of the moving jaw. The wedge factors at the center of the field in both symmetric and asymmetric fields are examined. The difference between calculated and measured wedge factors is within 1.0%. The method developed here is easy to implement. The only datum required in addition to the standard set of conventional physical wedge implementation data is the off-axis output factor for the open field in the reference condition. The off-center point calculation is also examined. For the off-center point calculation, the dose profile in the wedge direction for the largest EDW field is used to obtain the relative off-center ratio in any smaller wedge field. The accuracy of the off-center point calculation decreases when the point of calculation is too close to the field edge

  8. Comparison of dosimetric characteristics of Siemens virtual and physical wedges for ONCOR linear accelerator

    Directory of Open Access Journals (Sweden)

    Attalla Ehab

    2010-01-01

    Full Text Available Dosimetric properties of virtual wedge (VW and physical wedge (PW in 6- and 10-MV photon beams from a Siemens ONCOR linear accelerator, including wedge factors, depth doses, dose profiles, peripheral doses, are compared. While there is a great difference in absolute values of wedge factors, VW factors (VWFs and PW factors (PWFs have a similar trend as a function of field size. PWFs have stronger depth dependence than VWF due to beam hardening in PW fields. VW dose profiles in the wedge direction, in general, match very well with those of PW, except in the toe area of large wedge angles with large field sizes. Dose profiles in the nonwedge direction show a significant reduction in PW fields due to off-axis beam softening and oblique filtration. PW fields have significantly higher peripheral doses than open and VW fields. VW fields have similar surface doses as the open fields, while PW fields have lower surface doses. Surface doses for both VW and PW increase with field size and slightly with wedge angle. For VW fields with wedge angles 45° and less, the initial gap up to 3 cm is dosimetrically acceptable when compared to dose profiles of PW. VW fields in general use less monitor units than PW fields.

  9. Checks for quality control of wedge dynamics in treatment units and the planning system

    International Nuclear Information System (INIS)

    Mateos Salvador, P.; Rodriguez Lopez, B.; Font Gelabert, J.; Hernandez Rodriguez, J.; Arino Gil, A.

    2013-01-01

    The objective of this study is to verify the implementation of enhanced dynamic wedge (EDW) vary in the Eclipse planning system and the experimental determination of the parameters that define the dosimetry characteristics of enhanced dynamic wedge of our treatment units. (Author)

  10. Use of a wedge cuvette in thin layer photometry and its application to oximetry

    NARCIS (Netherlands)

    Spaan, J. A.; Garred, L. J.; van de Borne, P.

    1977-01-01

    A wedge cuvette was constructed by fixing 2 glass plates at a known angle with a spacer at one end. This resulted in a thin layer with thickness varying from 0 to 250 micrometer. By measuring the intensity of a beam of light through the thin layer as a function of distance along the wedge (and thus

  11. North Aegean core complexes, the gravity spreading of a thrust wedge

    NARCIS (Netherlands)

    Kydonakis, Konstantinos; Brun, Jean Pierre; Sokoutis, Dimitrios

    2015-01-01

    The North Aegean core complexes developed in middle Eocene soon after the end of continental block convergence and piling up of the Hellenic Thrust Wedge. They formed during back-arc extension, driven by the Hellenic slab rollback, at the back of the thrust wedge. A series of scaled laboratory

  12. Wedge gate valves selecting essentials in pipeline systems designing based on permissible operation parameters

    Science.gov (United States)

    Zakirnichnaya, M. M.; Kulsharipov, I. M.

    2017-10-01

    Wedge gate valves are widely used at the fuel and energy complex enterprises. The pipeline valves manufacturers indicate the safe operation resource according to the current regulatory and technical documentation. In this case, the resource value of the valve body strength calculation results is taken into consideration as the main structural part. However, it was determined that the wedge gate valves fail before the assigned resource due to the occurrence of conditions under which the wedge breaks in the hooks and, accordingly, the sealing integrity is not ensured. In this regard, it became necessary to assess the conditions under which the resource should be assigned not only to the valve body, but also to take into account the wedge durability. For this purpose, wedge resource calculations were made using the example of ZKL2 250-25 and ZKL2 300-25 valves using the ABAQUS software package FE-SAFE module under the technological parameters influence on the basis of their stressstrain state calculation results. Operating conditions, under which the wedge resource value is lower than the one set by the manufacturer, were determined. A technique for limiting the operating parameters for ensuring the wedge durability during the wedge gate valve assigned resource is proposed.

  13. SOFTWARE FOR COMPUTER-AIDED DESIGN OF CROSS-WEDGE ROLLING

    OpenAIRE

    A. A. Abramov; S. V. Medvedev

    2013-01-01

    The issues of computer technology creation of 3D-design and engineering analysis of metal forming processes using cross wedge rolling methods (CWR) are considered. The developed software for computer-aided design and simulation of cross-wedge rolling is described.

  14. Standing balance in people with trans-tibial amputation due to vascular causes: A literature review.

    Science.gov (United States)

    Seth, Mayank; Lamberg, Eric

    2017-08-01

    Balance is an important variable to consider during the rehabilitation process of individuals with trans-tibial amputation. Limited evidence exists on the balance abilities of people with trans-tibial amputation due to vascular causes. The purpose of this article is to review literature and determine if standing balance is diminished in people with trans-tibial amputation due to vascular causes. Literature review. Data were obtained from PubMed, Google Scholar, OandP.org , CINHAL, and Science Direct. Studies were selected only if they included standing balance assessment of people with unilateral trans-tibial amputation due to vascular causes. The review yielded seven articles that met the inclusion criteria. The general test methodology required participants to stand still on force platforms, with feet together, while center of pressure or postural sway was recorded. According to the findings of this review, individuals with trans-tibial amputees due to vascular causes have diminished balance abilities. Limited evidence suggests their balance might be further diminished as compared to individuals with trans-tibial amputation due to trauma. Although the evidence is limited, because of the underlying pathology and presence of comorbidities in individuals with trans-tibial amputation due to vascular causes, one cannot ignore these findings, as even a minor injury from a fall may develop into a non-healing ulcer and affect their health and well-being more severely than individuals with trans-tibial amputation due to trauma. Clinical relevance Individuals with trans-tibial amputation due to vascular causes have diminished balance abilities compared to healthy individuals and individuals with trans-tibial amputation due to trauma. This difference should be considered when designing and fabricating prostheses. Prosthetists and rehabilitation clinicians should consider designing amputation cause-specific rehabilitation interventions, focussing on balance and other

  15. Segmental transports for posttraumatic lower extremity bone defects: are femoral bone transports safer than tibial?

    Science.gov (United States)

    Liodakis, Emmanouil; Kenawey, Mohamed; Krettek, Christian; Ettinger, Max; Jagodzinski, Michael; Hankemeier, Stefan

    2011-02-01

    The long-term outcomes following femoral and tibial segment transports are not well documented. Purpose of the study is to compare the complication rates and life quality scores of femoral and tibial transports in order to find what are the complication rates of femoral and tibial monorail bone transports and if they are different? We retrospectively analyzed the medical records of 8 femoral and 14 tibial consecutive segment transports performed with the monorail technique between 2001 and 2008 in our institution. Mean follow-up was 5.1 ± 2.1 years with a minimum follow-up of 2 years. Aetiology of the defects was posttraumatic in all cases. Four femoral (50%) and nine tibial (64%) fractures were open. The Short Form-36 (SF-36) health survey was used to compare the life quality after femoral and tibial bone transports. The Mann-Whiney U test, Fisher exact test, and the Student's two tailed t-test were used for statistical analysis. P ≤ 0.05 was considered to be statistically significant. The tibial transport was associated with higher rates of severe complications and additional procedures (1.5 ± 0.9 vs. 3.4 ± 2.7, p = 0.048). Three patients of the tibial group were amputated because of recurrent infections and one developed a complete regenerate insufficiency that was treated with partial diaphyseal tibial replacement. Contrary to that none of patients of the femoral group developed a complete regenerate insufficiency or was amputated. Tibial bone transports have a higher rate of complete and incomplete regenerate insufficiency and can more often end in an amputation. The authors suggest systematic weekly controls of the CRP value and of the callus formation in patients with posttraumatic tibia bone transports. Further comparative studies comparing the results of bone transports with and without intramedullary implants are necessary.

  16. Tibial internal rotation negatively affects clinical outcomes in total knee arthroplasty: a systematic review.

    Science.gov (United States)

    Panni, Alfredo Schiavone; Ascione, Francesco; Rossini, Marco; Braile, Adriano; Corona, Katia; Vasso, Michele; Hirschmann, Michael T

    2017-12-15

    The aim of this systematic review is to analyze the effect of tibial rotational alignment after total knee arthroplasty (TKA) on clinical outcomes and assess the eventual cut-off values for tibial TKA rotation leading to poor outcomes. A detailed and systematic search from 1997 to 2017 of the Pubmed, Medline, Cochrane Reviews, and the Google Scholar databases was performed using the keyword terms "total knee arthroplasty", "total knee replacement", "tibial alignment", "tibial malalignement", "tibial rotation", "rotational error", "axis", "angle", "tibial malrotation", "clinical outcome", in several combinations. The modified Coleman scoring methodology (mCMS) was used. All the primary TKAs studies analyzing correlation between clinical results and tibial rotation were included. Five articles met the inclusion criteria. A total of 333 arthroplasties were included in this review; 139 had tibial component malalignment, while 194 were in control groups. The mean age of patients was 67.3 (SD 0.57) years. The mean average postoperative follow-up delay was 34.7 months (range 21-70). The mean mCMS score was 59.2 points indicating good methodological quality in the included studies. Functional outcomes were assessed through KSS, OKS, KOOS and VAS, negatively related to tibial internal rotation. Our review confirmed that excessive internal rotation of the tibial TKA component represents a significant risk factor for pain and inferior functional outcomes after TKA (> 10° of internal rotation demonstrated the common value), since external rotation does not affect the results. However, a universal precise cut-off value has not been found in the available literature and there remains a debate about CT rotation assessment and surgical intra-operative landmarks. III.

  17. Pilot production of the wedge filter for the TBI (total body irradiation)

    International Nuclear Information System (INIS)

    Ikezaki, Hiromi; Ikeda, Ikuo; Maruyama, Yasushi; Nako, Yasunobu; Tonari, Ayako; Kusuda, Junko; Takayama, Makoto

    2007-01-01

    Total body irradiation (TBI) is performed by various methods, such as a long SSD method and a translational couch method. For patient safety in carrying out TBI, the patient should be placed on the supine position and prone position near the floor. TBI is performed from 2 opposite ports (AP/PA) with a linear accelerator (10 MV X-ray). We experimented with a wedge filter for TBI created by us, which makes dose distribution to a floor uniform. The wedge filter, made of iron alloy, was attached to the linear accelerator. In designing the wedge filter, thickness of the lead-made wedge filter can be calculated numerically from the ratio of linear attenuation coefficient of iron alloy and lead. In measuring the dose profile for a phantom of 20 cm thick, dose homogeneity less than 10% was proved by the wedge filter for TBI. (author)

  18. Seismic characterization of a `compound tectonic wedge` beneath the Rocky Mountain foreland basin, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, D. C.; Sukaramongkol, C.; Spratt, D. A. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    1996-06-01

    The detailed internal geometry of a `compound tectonic wedge` beneath an eastward-dipping homocline in the Sundre area of southern Alberta was described. Data for the description was obtained by interpreting reflection seismic data. The wedge has been driven into the foreland succession beneath the gently dipping upper detachment which occurs within coal horizons of the Upper Brazeau Group. Shape of the upper detachment near its toe indicates that rocks in its hanging wall were decoupled from strain associated with forward emplacement of the wedge. Folding of the upper detachment occurs in the hinterland region of the wedge, with a new upper detachment developing above the fold. Emplacement of the wedge is suspected to be the result of excess pore fluid pressure, although proof of this happening awaits quantification of the mechanical model. 25 refs., 8 figs.

  19. Magnetization study of interlayer exchange in semiconductor EuS-PbS ferromagnetic wedge multilayers

    International Nuclear Information System (INIS)

    Kowalczyk, L.; Osinniy, V.; Chernyshova, M.; Dziawa, P.; Boratynski, A.; Story, T.; Smits, C.J.P.; Swagten, H.J.M.; Sipatov, A.Yu.; Volobuev, V.V.

    2006-01-01

    Interlayer coupling was experimentally studied in semiconductor EuS-PbS ferromagnetic superlattice wedge structures grown on KCl (0 0 1) substrates with the wedges covering the semiconductor nonmagnetic PbS spacer layer thickness from 0.3 to 6 nm. Structural parameters of the wedges were examined by X-ray diffraction analysis of EuS-PbS superlattice period. Measurements of magnetic hysteresis loops of EuS-PbS structures were performed by both SQUID (for small terminal parts of the wedge) and MOKE (magneto-optical analysis along the wedge) magnetometry. A strong decrease of magnetic remanence and an increase of saturation field observed for EuS-PbS structures with the PbS spacer thickness decreasing below about 1.5 nm is discussed in terms of the influence of antiferromagnetic interlayer coupling

  20. A study on a characteristic of stem friction coefficient for motor operated flexible wedge gate valve

    International Nuclear Information System (INIS)

    Kim, Dae-Woong; Park, Sung-Geun; Lee, Sang-Guk; Kang, Shin-Cheul

    2009-01-01

    Stem friction coefficient is a coefficient that represents friction between thread leads of the stem and stem nut. It is an important factor to determine output thrust delivered from the actuator to the valve stem in assessing performance of motor operated valves. This study analyzes the effects of changes in differential pressure on stem friction coefficient, and determines the bounding value of stem friction coefficient. A dynamic test was conducted on multiple flexible wedge gate valves in various differential pressure conditions, and the test data was statistically analyzed to determine the bounding value. The results show that stem friction coefficient in middle and high differential pressure is influenced by fluid pressure, while stem friction coefficient in low differential pressure is almost not affected by fluid pressure. In addition, it is found that the bounding value of stem friction coefficient is higher in a closing stroke than in an opening stroke.

  1. Plate Versus Intramedullary Nail Fixation of Anterior Tibial Stress Fractures: A Biomechanical Study.

    Science.gov (United States)

    Markolf, Keith L; Cheung, Edward; Joshi, Nirav B; Boguszewski, Daniel V; Petrigliano, Frank A; McAllister, David R

    2016-06-01

    Anterior midtibial stress fractures are an important clinical problem for patients engaged in high-intensity military activities or athletic training activities. When nonoperative treatment has failed, intramedullary (IM) nail and plate fixation are 2 surgical options used to arrest the progression of a fatigue fracture and allow bone healing. A plate will be more effective than an IM nail in preventing the opening of a simulated anterior midtibial stress fracture from tibial bending. Controlled laboratory study. Fresh-frozen human tibias were loaded by applying a pure bending moment in the sagittal plane. Thin transverse saw cuts, 50% and 75% of the depth of the anterior tibial cortex, were created at the midtibia to simulate a fatigue fracture. An extensometer spanning the defect was used to measure the fracture opening displacement (FOD) before and after the application of IM nail and plate fixation constructs. IM nails were tested without locking screws, with a proximal screw only, and with proximal and distal screws. Plates were tested with unlocked bicortical screws (standard compression plate) and locked bicortical screws; both plate constructs were tested with the plate edge placed 1 mm from the anterior tibial crest (anterior location) and 5 mm posterior to the crest. For the 75% saw cut depth, the mean FOD values for all IM nail constructs were 13% to 17% less than those for the saw cut alone; the use of locking screws had no significant effect on the FOD. The mean FOD values for all plate constructs were significantly less than those for all IM nail constructs. The mean FOD values for all plates were 28% to 46% less than those for the saw cut alone. Anterior plate placement significantly decreased mean FOD values for both compression and locked plate constructs, but the mean percentage reductions for locked and unlocked plates were not significantly different from each other for either plate placement. The percentage FOD reductions for all plate

  2. [Particular posteromedial and posterolateral approaches for the treatment of tibial head fractures].

    Science.gov (United States)

    Lobenhoffer, P; Gerich, T; Bertram, T; Lattermann, C; Pohlemann, T; Tscheme, H

    1997-12-01

    Tibial plateau fractures with depression of posterior aspects of the proximal tibia cause significant therapeutic problems. Posterior fractures on the medial side are mainly highly instable fracture-dislocations (Moore type I). Posterolateral fractures usually cause massive depression and destruction of the chondral surface. Surgical exposure of these fractures from anterior requires major soft tissue dissection and has a significant complication rate. However, incomplete restoration of the joint surface results in chronic postero-inferior joint subluxation, osteoarthritis and pain. We present new specific approaches for posterior fracture types avoiding large skin incisions, but allowing for atraumatic exposure, reduction and fixation. Posteromedial fracture-dislocations are exposed by a direct posteromedial skin incision and a deep incision between medial collateral ligament and posterior oblique ligament. The posteromedial pillar and the posterior flare of the proximal tibia are visualized. The inferior extent of the joint fragment can be reduced by indirect techniques or direct manipulation of the fragment. Fixation is achieved with subchondral lag screws and an anti-glide plate at the tip of the fragment. Posterolateral fractures are exposed by a transfibular approach: the skin is incised laterally, the peroneal nerve is dissected free. The fibula neck is osteotomized, the tibiofibular syndesmosis is divided and the fibula neck is reflected upwards in one layer with the meniscotibial ligament and the iliotibial tract attachment. Reflexion of the fibula head relaxes the lateral collateral ligament, allows for lateral joint opening and internal rotation of the tibia and thus exposes the posterolateral and posterior aspect of the tibial plateau. Fixation and buttressing on the posterolateral side can be achieved easily with this approach. In closure, the fibula head is fixed back with a lag screw or a tension-band system. These two exposures can be combined in

  3. Diagnostic imaging of tibial periosteal ganglion

    International Nuclear Information System (INIS)

    Valls, R.; Melloni, P.; Darnell, A.; Munoz, J.; Canalies, J.

    1997-01-01

    A case of a soft tissue tumor situated in the anterior surface of the proximal end of the tibia in an adult patient is demonstrated by conventional radiographs, CT, and MRI. The lesion was well defined with respect to the adjacent soft tissue. The CT exam showed a soft tissue mass with external cortical erosion and thick spicules by periosteal reaction. On T1-weighted images the mass was homogeneous and of low signal intensity, whereas on T2-weighted images it showed a high signal intensity, with some septa in the mass. The differential considerations include a periosteal chondroma, a lipoma, a subperiosteal hematoma, an inflammatory process, a giant cell tumor of tendon sheath, and a parosteal osteosarcoma. The CT and MR features of these entities are reviewed as an aid in differential diagnosis of the periosteal ganglion. (orig.). With 4 figs

  4. Preliminary assessment of potential underground stability (wedge and spalling) at Forsmark, Simpevarp and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Derek [Univ. of Alberta, Edmonton (Canada). Geotechnical Engineering

    2005-12-15

    stress. The analyses indicates however that the risk of spalling for the deposition holes increases below a depth 550 m. The spalling analyses for Simepvarp and Laxemar suggest that spalling will not be an issue in the deposition tunnels or deposition holes down to a depth of 650 m for Stress Domain II. In Stress Domain I, the analyses indicates that the risk for spalling in the deposition holes increases significantly below a depth of 450 m. It should be noted the experience with the underground excavations at a depth of 450 m at the nearby Aespoe Hard Rock Laboratory which is in a similar rock mass to that found at Simpevarp and Laxemar and similar stress domain as Domain I, did not show any evidence of spalling. The mean laboratory uniaxial compressive strength for the Simepvarp and Laxemar sites, which is used to estimate the rock mass spalling strength, is considerably less than that used for the Aespoe diorite and hence may be under estimated. This needs further investigations. The results from the Aespoe Pillar Stability Experiment that utilized 1.8-m-diameter boreholes suggest that should spalling be severe, as in this experiment, the increased borehole volume due to spalling could approach 0.18 m{sup 3}. This volume increase is approximately 18% greater then the 0.150 m{sup 3} proposed as an acceptable volume increase per deposition hole. In the Aespoe Pillar Stability Experiment the spalling was caused by excavation-induced stresses, i.e., after drilling, and thermally-induced stresses. The volume of spalling after drilling was approximately 30% of the total spalling volume. Hence it is highly unlikely that the volume increase caused by drilling-induced spalling will exceed the proposed allowable volume increase for any site. Wedge analysis requires detailed knowledge of the fracture system at the repository level. It was concluded that the DFN model may not contain sufficient information at this time for detailed wedge stability analyses and hence may not be

  5. Computer dosimetry for flattened and wedged fast-neutron beams

    International Nuclear Information System (INIS)

    Hogstrom, K.R.; Smith, A.R.; Almond, P.R.; Otte, V.A.; Smathers, J.B.

    1976-01-01

    Beam flattening by the use of polyethylene filters has been developed for the 50-MeV d→Be fast-neutron therapy beam at the Texas AandM Variable-Energy Cyclotron (TAMVEC) as a result of the need for a more uniform dose distribution at depth within the patient. A computer algorithm has been developed that allows the use of a modified decrement line method to calculate dose distributions; standard decrement line methods do not apply because of off-axis peaking. The dose distributions for measured flattened beams are transformed into distributions that are physically equivalent to an unflattened distribution. In the transformed space, standard decrement line theory yields a distribution for any field size which, by applying the inverse transformation, generates the flattened dose distribution, including the off-axis peaking. A semiempirical model has been constructed that allows the calculation of dose distributions for wedged beams from open-beam data

  6. Metamaterials based on wedge-shaped electrodynamic structures

    Directory of Open Access Journals (Sweden)

    Mitrokhin Vladimir

    2017-01-01

    Full Text Available The paper studies a possibility of simulation of artificial composite media with negative values of the real part of the equivalent dielectric (magnetic permittivity, by the use of segments of hollow composite waveguides with cylindrical guided waves in evanescent mode. Reactive evanescent fields of wedge-shaped waveguide eigenmodes are formed in the evanescent region before the critical section of the waveguide which separates the quasistatic field region from the distributing field of the evanescent waveguide mode. The possibility of simulation is determined by the equivalence of dispersion equation of the eigenmode propagation constant and the dispersion equation for the electric (magnetic permittivity of plasma-like medium if cut-off frequency and electric (magnetic plasma frequency of the medium are equal.

  7. Lower limit of strength wedge-type anchor bolts

    International Nuclear Information System (INIS)

    Arnedo Pena, A.; Frances Urmeneta, M.

    1998-01-01

    Simple expansion bolts, with a split expansion ring and a threaded bolt with an integral cone expander, called wedge type, are very used in securing and anchoring structures. The anchorage is obtained by a mechanism of torque-controlled expansion. Although less resistant than other types, its easy installation and low cost make them very competitive in light structures. In this paper, the minimum capacity values are analysed, when they are used to anchor safety-related equipment in NPP. The EPRI criteria developed in response to USI A-46 are applied and complemented by the new CEB Anchorage Design Guide. The results are compared with the information from european manufactures, adopting different safety factors for cracked and non-cracked concrete. With adequate control and inspection measures, including areas of noticeable cracking of concrete. minimum values for equipment can be obtained satisfying the strictest seismic validation requirements. (Author) 5 refs

  8. Deconvolving the wedge: maximum-likelihood power spectra via spherical-wave visibility modelling

    Science.gov (United States)

    Ghosh, A.; Mertens, F. G.; Koopmans, L. V. E.

    2018-03-01

    Direct detection of the Epoch of Reionization (EoR) via the red-shifted 21-cm line will have unprecedented implications on the study of structure formation in the infant Universe. To fulfil this promise, current and future 21-cm experiments need to detect this weak EoR signal in the presence of foregrounds that are several orders of magnitude larger. This requires extreme noise control and improved wide-field high dynamic-range imaging techniques. We propose a new imaging method based on a maximum likelihood framework which solves for the interferometric equation directly on the sphere, or equivalently in the uvw-domain. The method uses the one-to-one relation between spherical waves and spherical harmonics (SpH). It consistently handles signals from the entire sky, and does not require a w-term correction. The SpH coefficients represent the sky-brightness distribution and the visibilities in the uvw-domain, and provide a direct estimate of the spatial power spectrum. Using these spectrally smooth SpH coefficients, bright foregrounds can be removed from the signal, including their side-lobe noise, which is one of the limiting factors in high dynamics-range wide-field imaging. Chromatic effects causing the so-called `wedge' are effectively eliminated (i.e. deconvolved) in the cylindrical (k⊥, k∥) power spectrum, compared to a power spectrum computed directly from the images of the foreground visibilities where the wedge is clearly present. We illustrate our method using simulated Low-Frequency Array observations, finding an excellent reconstruction of the input EoR signal with minimal bias.

  9. Posterior coronal plating for tibial fractures: technique and advantages

    Directory of Open Access Journals (Sweden)

    Montu Jain

    2014-04-01

    Full Text Available Objective:Tibial shaft fractures are straightforward to treat but when associated with soft tissue injury particularly at the nail entry/plate insertion site or there is significant comminution proximally or a large butterfly fragment/a second split component in the posterior coronal plane, it is a challenge to the treating surgeon. The aim of the present report is to describe the technique of posterior coronal plating in such a scenario and its advantages. Methods:Between July 2008 and June 2011, 12 patients were pro spectively treated by this approach using 4.5 mm broad dynamic compression plates. Results:The time of bony consolidation and full weight bearing averaged 21.7 weeks (range, 16-26 weeks. Patients were followed up for at least 24 months (range, 24-48 months. At 1 year postoper atively, no loss in reduction or alignment was observed. Mean Hospital for Lower Extremity Measurement Functional Score was 72.8 (range, 64-78. All patients were satisfied with their treatment outcomes. Conclusion:Direct posterior approach and fixation using prone position helps to visualise the fracture fragments and provide rigid fixation. The approach is simple and extensile easily, apart from advantages of less soft tissue and hardware problems compared to standard medial or lateral plating. Key words: Tibial fractures; Bone plates; Orthopedic procedures

  10. Thrombosed Popliteal Artery Pseudoaneurysm as Herald of Tibial Osteochondroma

    Directory of Open Access Journals (Sweden)

    A.M. Ruales Romero

    Full Text Available Background: Osteochondroma is the most common non-malignant tumour of bone, accounting for approximately one third of benign lesions in the skeleton. They often develop around the knee in the distal femur and in the proximal tibia and fibula. They present as a painless slow growing mass during adolescence and have been reported to cause damage to adjacent structures such as blood vessels; arterial damage is more common than venous injury and is usually a result of compression, stretching, and rubbing of the arterial wall. Such lesions include stenosis, thrombosis, and pseudoaneurysm formation possibly causing lower limb claudication or acute limb ischemia. Methods: An 18 year old male patient with a 4 week history of pain, hematoma, and oedema of the left calf without previous trauma is reported. A computed tomography scan (CT revealed a large popliteal artery pseudoaneurysm and its close relationship to a protrusion of the proximal tibia. Results: The popliteal artery was repaired by an external saphenous patch and the exostosis was removed. The patient had palpable popliteal and distal pulses after surgery and during the first year follow-up. Conclusions: Tibial osteochondroma should be considered in the differential diagnosis in young patients, among the potential causes of pseudoaneurysm of the femoral or popliteal artery. Surgical repair should be performed to restore normal blood flow with resection of the exostosis to prevent recurrence. Keywords: Popliteal artery, Pseudoaneurysm, Tibial exostosis, Osteochondroma

  11. Free flap reconstructions of tibial fractures complicated after internal fixation.

    Science.gov (United States)

    Nieminen, H; Kuokkanen, H; Tukiainen, E; Asko-Seljavaara, S

    1995-04-01

    The cases of 15 patients are presented where microvascular soft-tissue reconstructions became necessary after internal fixation of tibial fractures. Primarily, seven of the fractures were closed. Eleven fractures had originally been treated by open reduction and internal fixation using plates and screws, and four by intramedullary nailing. All of the patients suffered from postoperative complications leading to exposure of the bone or fixation material. The internal fixation material was removed and radical revision of dead and infected tissue was carried out in all cases. Soft tissue reconstruction was performed using a free microvascular muscle flap (11 latissimus dorsi, three rectus abdominis, and one gracilis). In eight cases the nonunion of the fracture indicated external fixation. The microvascular reconstruction was successful in all 15 patients. In one case the recurrence of deep infection finally indicated a below-knee amputation. In another case, chronic infection with fistulation recurred postoperatively. After a mean follow-up of 26 months the soft tissue coverage was good in all the remaining 13 cases. All the fractures united. Microvascular free muscle flap reconstruction of the leg is regarded as a reliable method for salvaging legs with large soft-tissue defects or defects in the distal leg. If after internal fixation of the tibial fracture the osteosynthesis material or fracture is exposed, reconstruction of the soft-tissue can successfully be performed by free flap transfer. By radical revision, external fixation, bone grafting, and a free flap the healing of the fracture can be achieved.

  12. Dosimetric parameters of enhanced dynamic wedge for treatment planning and verification

    International Nuclear Information System (INIS)

    Leavitt, Dennis D.; Lee, Wing Lok; Gaffney, David K.

    1996-01-01

    Purpose/Objective: Enhanced Dynamic Wedge (EDW) is an intensity-modulated radiotherapy technique in which one collimating jaw sweeps across the field to define a desired wedge dose distribution while dose rate is modified according to jaw position. This tool enables discrete or continuous wedge angles from zero to sixty degrees for field widths from three cm to 30 cm in the direction of the wedge, and up to 40 cm perpendicular to the wedge direction. Additionally, asymmetric wedge fields not centered on the line through isocenter can be created for applications such as tangential breast irradiation. The unique range of field shapes and wedge angles introduce a new set of dosimetric challenges to be resolved before routine clinical use of EDW, and especially require that a simple set of independent dose calculation and verification techniques be developed to check computerized treatment planning results. Using terminology in common use in treatment planning, this work defines the effective wedge factor vs. field width and wedge angle, evaluates the depth dose vs. open field values, defines primary intensity functions from which specific dynamic wedges can be calculated in treatment planning systems, and describes the technique for independent calculation of Monitor Units for EDW fields. Materials and Methods: Using 6- and 18-MV beams from a CI2100C, EDW beam profiles were measured in water phantom for depths from near-surface to 30 cm for the full range of field widths and wedge angles using a linear detector array of 25 energy-compensated diodes. Asymmetric wedge field profiles were likewise measured. Depth doses were measured in water phantom using an ionization chamber sequentially positioned to depths of 30 cm. Effective wedge factors for the full range of field widths and wedge angles were measured using an ionization chamber in water-equivalent plastic at a depth of 10 cm on central axis. Dose profiles were calculated by computer as the summation of a series

  13. A 3D finite element model to investigate prosthetic interface stresses of different posterior tibial slope.

    Science.gov (United States)

    Shen, Yi; Li, Xiaomiao; Fu, Xiaodong; Wang, Weili

    2015-11-01

    Posterior tibial slope that is created during proximal tibial resection in total knee arthroplasty has emerged as an important factor in the mechanics of the knee joint and the surgical outcome. But the ideal degree of posterior tibial slope for recovery of the knee joint function and preventions of complications remains controversial and should vary in different racial groups. The objective of this paper is to investigate the effects of posterior tibial slope on contact stresses in the tibial polyethylene component of total knee prostheses. Three-dimensional finite element analysis was used to calculate contact stresses in tibial polyethylene component of total knee prostheses subjected to a compressive load. The 3D finite element model of total knee prosthesis was constructed from the images produced by 3D scanning technology. Stresses in tibial polyethylene component were calculated with four different posterior tibial slopes (0°, 3°, 6° and 9°). The 3D finite element model of total knee prosthesis we presented was well validated. We found that the stress distribution in the polythene as evaluated by the distributions of the von Mises stress, the maximum principle stress, the minimum principle stress and the Cpress were more uniform with 3° and 6° posterior tibial slopes than with 0° and 9° posterior tibial slopes. Moreover, the peaks of the above stresses and trends of changes with increasing degree of knee flexion were more ideal with 3° and 6° posterior slopes. The results suggested that the tibial component inclination might be favourable to 7°-10° so far as the stress distribution is concerned. The range of the tibial component inclination also can decrease the wear of polyethylene. Chinese posterior tibial slope is bigger than in the West, and the current domestic use of prostheses is imported from the West, so their demands to tilt back bone cutting can lead to shorten the service life of prostheses; this experiment result is of important

  14. Deep long-period earthquakes west of the volcanic arc in Oregon: evidence of serpentine dehydration in the fore-arc mantle wedge

    Science.gov (United States)

    Vidale, John E.; Schmidt, David A.; Malone, Stephen D.; Hotovec-Ellis, Alicia J.; Moran, Seth C.; Creager, Kenneth C.; Houston, Heidi

    2014-01-01

    Here we report on deep long-period earthquakes (DLPs) newly observed in four places in western Oregon. The DLPs are noteworthy for their location within the subduction fore arc: 40–80 km west of the volcanic arc, well above the slab, and near the Moho. These “offset DLPs” occur near the top of the inferred stagnant mantle wedge, which is likely to be serpentinized and cold. The lack of fore-arc DLPs elsewhere along the arc suggests that localized heating may be dehydrating the serpentinized mantle wedge at these latitudes and causing DLPs by dehydration embrittlement. Higher heat flow in this region could be introduced by anomalously hot mantle, associated with the western migration of volcanism across the High Lava Plains of eastern Oregon, entrained in the corner flow proximal to the mantle wedge. Alternatively, fluids rising from the subducting slab through the mantle wedge may be the source of offset DLPs. As far as we know, these are among the first DLPs to be observed in the fore arc of a subduction-zone system.

  15. Reamed intramedullary exchange nailing in the operative treatment of aseptic tibial shaft nonunion.

    Science.gov (United States)

    Hierholzer, Christian; Friederichs, Jan; Glowalla, Claudio; Woltmann, Alexander; Bühren, Volker; von Rüden, Christian

    2017-08-01

    The aim of this study was to evaluate a standardized treatment protocol regarding the rate of secondary bone union, complications, and functional outcome. This study was started as a prospective study in a single Level I Trauma Centre between 2003 and 2012. The study group consisted of 188 patients with the diagnosis of an aseptic tibial shaft nonunion. Exchange nailing was performed following a standardized surgical protocol. Long-term follow-up was analyzed for rate of bone healing and functional outcome. Osseous healing was achieved in 182 out of 188 patients (97 %). In 165 out of 188 patients (88 %), bone healing was observed timely and uneventfully after a single exchange nailing procedure. An open approach was necessary in 32 patients (17 %). Twenty-three patients (12 %) required additional therapy such as extracorporeal shock wave therapy. Post-operative complications were observed in seven patients (4 %). Almost all patients demonstrated osseous healing within 12 months, with the majority of osseous healing occurring within six months. A relevant shortening of the fractured tibia was observed in 20 out of 188 patients (11 %). After a median follow-up of 23 months (range 12-45 months), outcome was evaluated using the assessment system of Friedman/Wyman. In summary, 154 out of 188 patients (82 %) had a good functional long-term result. Reamed intramedullary exchange nailing including correction of axis alignment is a safe and effective treatment of aseptic tibial shaft nonunion with a high rate of bone healing and a good radiological and functional long-term outcome.

  16. Operative Versus Conservative Management of Displaced Tibial Shaft Fracture in Adolescents.

    Science.gov (United States)

    Kinney, Matthew C; Nagle, David; Bastrom, Tracey; Linn, Michael S; Schwartz, Alexandra K; Pennock, Andrew T

    2016-01-01

    Displaced tibial shaft fractures are common in adolescent patients, yet there is no standardized management strategy. We compared surgical fixation and closed reduction and casting (CRC) of these fractures to assess treatment outcomes and determine predictors of failure. We retrospectively reviewed all patients aged 12 to 18 who presented with a displaced tibial shaft fracture that required reduction over an 8-year period. Exclusion criteria included open fractures and lack of follow-up to radiographic union or to 6 months from the index procedure. Fractures were initially treated based on surgeon preference either with CRC or with immediate intramedullary nailing. Seventy-four patients met inclusion criteria: 57 were initially managed with CRC and 17 with operative fixation. Radiographic healing was defined as bridging of 3 cortices and adequacy of final alignment was defined as 20% (odds ratio=7.8, Palignment (92.5% vs. 72.4%, P=0.10) but required longer hospitalization (5.4 vs. 1.9 d, P<0.001) and had a higher incidence of anterior knee pain (20% vs. 0%, P<0.01). There was no significant difference between groups with respect to time to healing. Treatment outcomes between initial operative fixation and closed reduction of displaced tibia fractures in adolescents are similar, but patients must be counseled about the high failure rates with CRC. Predictors of CRC failure include initial fracture displacement and the presence of a fibula fracture-these variables should be considered when selecting a treatment method. Level III-Therapeutic study.

  17. Leptin differentially regulates chondrogenesis in mouse vertebral and tibial growth plates.

    Science.gov (United States)

    Yu, Bo; Jiang, Kaibiao; Chen, Bin; Wang, Hantao; Li, Xinfeng; Liu, Zude

    2017-05-31

    Leptin plays an important role in mediating chondrogenesis of limb growth plate. Previous studies suggest that bone structures and development of spine and limb are different. The expression of Ob-Rb, the gene that encodes leptin receptors, is vertebral and appendicular region-specific, suggesting the regulation of leptin on VGP and TGP chondrogenesis may be very different. The aim of the present study was to investigate the differential regulation of leptin on the chondrogenesis of vertebral growth plate (VGP) and tibial growth plate (TGP). We compared the VGP and TGP from wild type (C57BL/6) and leptin-deficient (ob/ob) mice. We then generated primary cultures of TGP and VGP chondrocytes. By treating the primary cells with different concentrations of leptin in vitro, we analyzed proliferation and apoptosis of the primary chondrocytes from TGP and VGP. We further measured expression of chondrogenic-related genes in these cells that had been incubated with different doses of leptin. Leptin-deficient mice of 8-week-old had shorter tibial and longer vertebral lengths than the wide type mice. Disturbed columnar structure was observed for TGP but not for VGP. In primary chondrocyte cultures, leptin inhibited VGP chondrocyte proliferation but promoted their apoptosis. Collagen IIA and aggrecan mRNA, and the protein levels of proliferation- and chondrogenesis-related markers, including PCNA, Sox9, and Smad4, were downregulated by leptin in a dose-dependent manner. In contrast, leptin stimulated the proliferation and chondrogenic differentiation of TGP chondrocytes at physiological levels (i.e., 10 and 50 ng/mL) but not at high levels (i.e., 100 and 1000 ng/mL). Leptin exerts a stimulatory effect on the proliferation and chondrogenic differentiation of the long bone growth plate but an inhibitory effect on the spine growth plate. The ongoing study will shed light on the regulatory mechanisms of leptin in bone development and metabolism.

  18. Functional outcome of tibial fracture with acute compartment syndrome and correlation to deep posterior compartment pressure.

    Science.gov (United States)

    Goyal, Saumitra; Naik, Monappa A; Tripathy, Sujit Kumar; Rao, Sharath K

    2017-05-18

    To measure single baseline deep posterior compartment pressure in tibial fracture complicated by acute compartment syndrome (ACS) and to correlate it with functional outcome. Thirty-two tibial fractures with ACS were evaluated clinically and the deep posterior compartment pressure was measured. Urgent fasciotomy was needed in 30 patients. Definite surgical fixation was performed either primarily or once fasciotomy wound was healthy. The patients were followed up at 3 mo, 6 mo and one year. At one year, the functional outcome [lower extremity functional scale (LEFS)] and complications were assessed. Three limbs were amputated. In remaining 29 patients, the average times for clinical and radiological union were 25.2 ± 10.9 wk (10 to 54 wk) and 23.8 ± 9.2 wk (12 to 52 wk) respectively. Nine patients had delayed union and 2 had nonunion who needed bone grafting to augment healing. Most common complaint at follow up was ankle stiffness (76%) that caused difficulty in walking, running and squatting. Of 21 patients who had paralysis at diagnosis, 13 (62%) did not recover and additional five patients developed paralysis at follow-up. On LEFS evaluation, there were 14 patients (48.3%) with severe disability, 10 patients (34.5%) with moderate disability and 5 patients (17.2%) with minimal disability. The mean pressures in patients with minimal disability, moderate disability and severe disability were 37.8, 48.4 and 58.79 mmHg respectively ( P fractures causes severe functional disability in majority of patients. These patients are prone for delayed union and nonunion; however, long term disability is mainly because of severe soft tissue contracture. Intra-compartmental pressure (ICP) correlates with functional disability; patients with relatively high ICP are prone for poor functional outcome.

  19. Impact of Fixed-Bearing and Mobile-Bearing Tibial Insert in Unicondylar Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Mehmet Faruk Çatma

    2016-06-01

    Full Text Available INTRODUCTION: The aim of the study is to investigate the impact of fixed or mobile-bearing tibial inserts on patellofemoral arthrosis and evaluate which one to be preferred for patients with patellofemoral arthrosis. METHODS: Operated in our clinic between January 2009 and February 2013, 33 with patellofemoral arthritis together with anteromedial compartment arthritis were included in the study. Patellofemoral joints of patients were evaluated according to the scoring system defined by Fulkerson-Shea. RESULTS: Unicondylar knee arthroplasty with fixed-bearing tibial insertsand 22 (66,6% (male: 3, female: 19 and unicondylar knee arthroplasty with mobile-bearing tibial inserts 11 (33,9 % (male: 2, female: 9 were implanted.Average knee flexion was found to be 116,5 (100-135 degrees in 22 patients with mobile-bearing tibial inserts, and 114,5 (95-135 in 11 patients with fixed-bearing tibial inserts. DISCUSSION AND CONCLUSION: Patellofemoral arthrosis is an important factor for unicondylar knee arthroplasty prognosis and one of the determinants of patient satisfaction. Significantly less patellofemoral complaints were seen with UKA with fixed-bearing tibial insert compared to mobile-bearing tibial insert.

  20. Ultrasound Guidance in Performing a Tendoscopic Surgery to Treat Posterior Tibial Tendinitis: A Useful Tool?

    Directory of Open Access Journals (Sweden)

    Akinobu Nishimura

    2016-01-01

    Full Text Available A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

  1. The accuracy of intramedullary tibial guide of sagittal alignment of PCL-substituting total knee arthroplasty.

    Science.gov (United States)

    Han, Hyuk-Soo; Kang, Seung-Baik; Jo, Chris H; Kim, Sun-Hong; Lee, Jung-Ha

    2010-10-01

    Experimental and clinical studies on the accuracy of the intramedullary alignment method have produced different results, and few have addressed accuracy in the sagittal plane. Reported deviations are not only attributable to the alignment method but also to radiological errors. The purpose of this study was to evaluate the accuracy of the intramedullary alignment method in the sagittal plane using computed tomography (CT) and 3-dimensional imaging software. Thirty-one TKAs were performed using an intramedullary alignment method involving the insertion of a long 8-mm diameter rod into the medullary canal to the distal metaphysis of the tibia. All alignment instruments were set to achieve an ideal varus/valgus angle of 0° in the coronal plane and a tibial slope of 0° in the sagittal plane. The accuracy of the intramedullary alignment system was assessed by measuring the coronal tibial component angle and sagittal tibial slope angles, i.e., angles between the tibial anatomical axis and the tangent to the medial and lateral tibial plateau or the cut-surface. The mean coronal tibial component angle was 88.5° ± 1.2° and the mean tibial component slope in the sagittal plane was 1.6° ± 1.2° without anterior slope. Our intramedullary tibial alignment method, which involves passing an 8-mm diameter long rod through the tibial shaft isthmus, showed good accuracy (less than 3 degrees of variation and no anterior slope) in the sagittal plane in neutral or varus knees.

  2. Extramedullary versus intramedullary tibial cutting guides in megaprosthetic total knee replacement

    Directory of Open Access Journals (Sweden)

    Karade Vikas

    2012-10-01

    Full Text Available Abstract Background In a standard total knee replacement, tibial component alignment is a key factor for the long term success of the surgery. The purpose of this study is to compare the accuracy of extramedullary and intramedullary tibial cutting guides used in indigenous and imported implants respectively, in positioning of the tibial components in megaprosthetic knee replacements. Methods A comparative study of the accuracy of extramedullary and intramedullary tibial cutting guides was carried out in 92 megaprosthetic knee replacements for distal femoral tumors. For the proximal tibia cut for tibial component placement, an extramedullary guide was used in 65 patients and an intramedullary guide was used in 27 patients. Tibial component alignment angles were measured in postoperative X-rays with the help of CAD software. Results There was more varus placement in coronal plane with extramedullary cutting guide (−1.18 +/− 2.4 degrees than the intramedullary guide (−0.34 +/− 2.31 degrees but this did not reach statistical significance. The goal of 90 +/− 2 degrees alignment of tibial component was achieved in 54% of patients in the extramedullary group versus 67% in the intramedullary group. In terms of sagittal plane alignment, extramedullary guide showed less accurate results (2.09 +/− 2.4 degrees than intramedullary guide (0.50 +/− 3.80 degrees for tibial component alignment, though 78% of patients were aligned within the goal of 0–5 degrees of tibial slope angle in extramedullary group versus 63% in intramedullary group. The mean error in the measurements due to rotation of the knee during taking the X-rays was less than 0.1 degrees and distribution of the X-rays with the rotation of knee was similar in both the groups. Conclusions Overall, in megaprosthetic knee replacement intramedullary guides gave more accurate results in sagittal plane and exhibited similar variability as of extramedullary guides in coronal plane.

  3. A non-deltaic clinoform wedge fed by multiple sources off São Sebastião Island, southeastern Brazilian Shelf

    Science.gov (United States)

    Vieira, Ivo; Lobo, Francisco José; Montoya-Montes, Isabel; Siegle, Eduardo; Passos, Jorge Luiz; De Mahiques, Michel Michaelovitch

    2018-02-01

    São Sebastião Island (SSI) marks the latitudinal boundary between two sedimentological and geochemical provinces in the São Paulo Bight, an arc-shaped sector of the southeastern Brazilian Shelf. The island is separated from the continent by the narrow, deep São Sebastião Channel (SSC). A relatively thick sediment wedge—the São Sebastião Wedge (SSW)—has been formed offshore SSI. This study explores the possible genetic and evolutionary mechanisms of the wedge, bearing in mind that clinoform wedges can form at considerable distances from major fluvial sources. For that, a marine geological database has been interpreted comprising high-resolution seismic data, a surficial sediment map and several sediment cores, from which radiocarbon dates were obtained and sedimentation rates deduced. A wave model was also applied to obtain the dominant wave directions. The SSW is a wedge-shaped deposit, and its internal structure presents three seismic units. The two lowest are wedge shaped and arranged in a backstepping pattern. The most recent unit is mostly aggradational and can be divided into three seismic subunits. Sedimentological data show that at least the most recent unit is composed of a mixture of sands and silts. Modeled wave conditions indicate a major influence from southerly waves that are able to remobilize shelf sediments and to create a bypass sediment zone until the foreset of the deposit is reached at the water depths where the SSW is found. Taken together, these data suggest that the SSW formed through contributions from different sediment sources, and should be regarded as an intermediate case of a non-deltaic clinoform wedge. Sand transport in the area involves wind-driven currents passing through the SSC and sediment remobilization by energetic southerly waves. Fine-grained sediment is derived mostly from the joint contributions of many minor catchments located north of the island, and this sediment is later transported southwestward by the

  4. Late Holocene ice wedges near Fairbanks, Alaska, USA: Environmental setting and history of growth

    Science.gov (United States)

    Hamilton, T.D.; Ager, T.A.; Robinson, S.W.

    1983-01-01

    Test trenches excavated into muskeg near Fairbanks in 1969 exposed a polygonal network of active ice wedges. The wedges occur in peat that has accumulated since about 3500 yr BP and have grown episodically as the permafrost table fluctuated in response to fires, other local site conditions and perhaps regional climatic changes. Radiocarbon dates suggest one or two episodes of ice-wedge growth between about 3500 and 2000 yr BP as woody peat accumulated at the site. Subsequent wedge truncation evidently followed a fire that charred the peat. Younger peat exhibits facies changes between sedge-rich components that filled troughs over the ice wedges and woody bryophytic deposits that formed beyond the troughs. A final episode of wedge development took place within the past few hundred years. Pollen data from the site indicate that boreal forest was present throughout the past 6000 yr, but that it underwent a gradual transition from a predominantly deciduous to a spruce-dominated assemblage. This change may reflect either local site conditions or a more general climatic shift to cooler, moister summers in late Holocene time. The history of ice-wedge growth shows that wedges can form and grow to more than 1 m apparent width under mean annual temperatures that probably are close to those of the Fairbanks area today (-3.5°C) and under vegetation cover similar to that of the interior Alaskan boreal forest. The commonly held belief that ice wedges develop only below mean annual air temperatures of -6 to -8°C in the zone of continuous permafrost is invalid.

  5. Observations of Lower Mississippi River Estuarine Dynamics: Effects of the Salt Wedge on Sediment Deposition

    Science.gov (United States)

    Ramirez, M. T.; Allison, M. A.

    2017-12-01

    The lowermost Mississippi River is subject to salt-wedge estuarine conditions during seasonally low flow, when seaward flow is unable to overcome density stratification. Previous studies in the Mississippi River salt wedge have shown the deposition of a fine sediment layer accumulating several mm/day beneath the reach where the salt wedge is present. Field studies were conducted during low flow in 2012-2015 utilizing ADCP, CTD, LISST, and physical samples to observe the physics of the salt wedge reach and to calculate rates and character of sediment trapping beneath the salt wedge. The field observations were summarized using a two-layer box-model representation of the reach to calculate water and sediment budgets entering, exiting, and stored within the reach. The salt wedge reach was found to be net depositional at rates up to 1.8 mm/day. The mechanism for transferring sediment mass from the downstream-flowing fluvial layer to the upstream-flowing marine layer appears to be flocculation, evidenced in LISST data by a spike in sediment particle diameters at the halocline. Applying reach-averaged rates of sediment trapping to a time-integrated model of salt-wedge position, we calculated annual totals ranging from 0.025 to 2.2 million tons of sediment deposited beneath the salt wedge, depending on salt-wedge persistence and upstream extent. Most years this seasonal deposit is remobilized during spring flood following the low-flow estuarine season, which may affect the timing of sediment delivery to the Gulf of Mexico, as well as particulate organic carbon, whose transport trajectory mirrors that of mineral sediment. These results are also relevant to ongoing dredging efforts necessary to maintain the economically-important navigation pathway through the lower Mississippi River, as well as planned efforts to use Mississippi River sedimentary resources to build land in the degrading Louisiana deltaic coast.

  6. Intercalary bone segment transport in treatment of segmental tibial defects

    International Nuclear Information System (INIS)

    Iqbal, A.; Amin, M.S.

    2002-01-01

    Objective: To evaluate the results and complications of intercalary bone segment transport in the treatment of segmental tibial defects. Design: This is a retrospective analysis of patients with segmental tibial defects who were treated with intercalary bone segment transport method. Place and Duration of Study: The study was carried out at Combined Military Hospital, Rawalpindi from September 1997 to April 2001. Subjects and methods: Thirteen patients were included in the study who had developed tibial defects either due to open fractures with bone loss or subsequent to bone debridement of infected non unions. The mean bone defect was 6.4 cms and there were eight associated soft tissue defects. Locally made unilateral 'Naseer-Awais' (NA) fixator was used for bone segment transport. The distraction was done at the rate of 1mm/day after 7-10 days of osteotomy. The patients were followed-up fortnightly during distraction and monthly thereafter. The mean follow-up duration was 18 months. Results: The mean time in external fixation was 9.4 months. The m ean healing index' was 1.47 months/cm. Satisfactory union was achieved in all cases. Six cases (46.2%) required bone grafting at target site and in one of them grafting was required at the level of regeneration as well. All the wounds healed well with no residual infection. There was no residual leg length discrepancy of more than 20 mm nd one angular deformity of more than 5 degrees. The commonest complication encountered was pin track infection seen in 38% of Shanz Screws applied. Loosening occurred in 6.8% of Shanz screws, requiring re-adjustment. Ankle joint contracture with equinus deformity and peroneal nerve paresis occurred in one case each. The functional results were graded as 'good' in seven, 'fair' in four, and 'poor' in two patients. Overall, thirteen patients had 31 (minor/major) complications with a ratio of 2.38 complications per patient. To treat the bone defects and associated complications, a mean of

  7. From guidelines to standards of care for open tibial fractures.

    Science.gov (United States)

    Trickett, R W; Rahman, S; Page, P; Pallister, I

    2015-09-01

    The standards for the management of open fractures of the lower limb published by the British Association of Plastic, Reconstructive and Aesthetic surgeons (BAPRAS) and British Orthopaedic Association (BOA) were introduced to improve the treatment received by patients after open injury to the lower limb. These Standards were released after BAPRAS/BOA published Guidelines for the management of open tibial fractures. We wished to determine the impact of these Standards upon the surgical management of open tibial fractures by comparing patients admitted to an orthoplastic centre in the 45 months concluding December 2009 (the Guidelines era) with those admitted during 2011 (the Standards era). Surgical procedures required during the first 30 days and 12 months after injury were determined. Cases were divided into 'directly admitted patients' (DAP) and 'transferred patients' (TP). Standards-era patients were divided further into those who had surgery exclusively at the orthoplastic centre (orthoplastic patients (OPP)) and those transferred after surgery (TASP). The number of TP trebled in frequency in the Standards era, 25% of whom were transferred before surgery. Significantly fewer surgical procedures were required for DAP and OPP groups compared with TP (and TASP) groups in both eras (Mann-Whitney U-test, p=0.05). DAP and OPP groups during the Standards era underwent the fewest procedures, with the vast majority of cases treated with two or fewer procedures in the first 12 months (88% and 80%, respectively, compared with 61% in the Guidelines era). In the Guidelines era, 44% of TP cases and in the Standards era 39% of TP and 29% of TASP groups underwent two or fewer procedures. Approximately two-thirds of open tibial fractures managed in our orthoplastic centre were patients transferred after surgery. The greatest impact of the Standards was evident for those who underwent surgery exclusively in the orthoplastic centre, reflecting a more deliberate combined strategy

  8. Medial tibial pain. A prospective study of its cause among military recruits.

    Science.gov (United States)

    Milgrom, C; Giladi, M; Stein, M; Kashtan, H; Margulies, J; Chisin, R; Steinberg, R; Swissa, A; Aharonson, Z

    1986-12-01

    In a prospective study of 295 infantry recruits during 14 weeks of basic training, 41% had medial tibial pain. Routine scintigraphic evaluation in cases of medial tibial bone pain showed that 63% had abnormalities. A stress fracture was found in 46%. Only two patients had periostitis. None had ischemic medial compartment syndrome. Physical examination could not differentiate between cases with medial tibial bone pain secondary to stress fractures and those with scintigraphically normal tibias. When both pain and swelling were localized in the middle one-third of the tibia, the lesion most likely proved to be a stress fracture.

  9. Variations in depth-dose data between open and wedge fields for 4-MV x-rays

    International Nuclear Information System (INIS)

    Sewchand, W.; Khan, F.M.; Williamson, J.

    1978-01-01

    Central-axis depth-dose data for 4-MV x rays, including tissue-maximum ratios, were measured for wedge fields. Comparison with corresponding open-field data revealed differences in magnitude which increased with depth, field size, and wedge thickness. However, phantom scatter correction factors for the wedge fields differed less than 1% from corresponding open-field factors. The differences in central-axis percent depth doses between the two types of fields indicate beam hardening by the wedge filter. This study also implies that the derivation of tissue-maximum ratios from central-axis percent depth is as valid for wedge as for open fields

  10. The effect of shoe design and lateral wedging on knee loading

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of the knee loading, but the importance of footwear design...... shoe were revealed. Conclusion: Lateral wedging is effective regardless of shoe design. Differences between the four neutral walking conditions underline the importance of footwear choice in individuals. It is safe to apply lateral wedges without jeopardizing muscular control during walking regardless...

  11. Physical optics-based diffraction coefficient for a wedge with different face impedances.

    Science.gov (United States)

    Umul, Yusuf Ziya

    2018-03-20

    A new diffraction field expression is introduced with the aid of the modified theory of physical optics for a wedge with different face impedances. First, the scattered geometrical optics fields are determined when both faces of the wedge are illuminated by the incident wave. The geometrical optics waves are then expressed in terms of the sum of two different fields that occur for different impedance wedges. The diffracted fields are determined for the two cases separately, and the total diffracted field is obtained as a sum of these waves. Lastly, the uniform field expressions are obtained, and the resultant fields are numerically compared with the solution of Maliuzhinets.

  12. Intercomparison of wedge factor for symmetric field and asymmetric field used 6MV linac

    International Nuclear Information System (INIS)

    Ji, Youn Sang; Han, Jae Jin

    1999-01-01

    Therapy equipment have taken progress for Cancer make use of Radiation for the normal tissue system make much of important for shielding. In modern times independent jaw setting to used equipment as possible make use of asymmetric field. Therefore, the asymmetric field be leave out of consideration wedge factor because of with used wedge for the most of part. These experimentation find out have an effect on the dosimetry of out put compared with of the difference between the symmetric field and asymmetric field for the wedge factor

  13. A study on the stem friction coefficient with differential pressure conditions for the motor operated flexible wedge gate valve

    International Nuclear Information System (INIS)

    Kim, Dae Woong; Park, Sung Keun; Kim, Yang Seok; Lee, Do Hwan

    2008-01-01

    Stem friction coefficient is very important parameter for the evaluation of valve performance. In this study, the characteristics of stem friction coefficient is analyzed, and the bounding value is determined. The hydraulic testing is performed for flexible wedge gate valves in the plant and statistical method is applied to the determination of bounding value. According to the results of this study, stem friction coefficient is not effected in low differential pressure condition, but it is showed different distribution in medium and high differential pressure condition. And the bounding value of closing stroke is higher than that of opening stroke

  14. Posterior tibial slope impacts intraoperatively measured mid-flexion anteroposterior kinematics during cruciate-retaining total knee arthroplasty.

    Science.gov (United States)

    Dai, Yifei; Cross, Michael B; Angibaud, Laurent D; Hamad, Cyril; Jung, Amaury; Jenny, Jean-Yves

    2018-02-23

    Posterior tibial slope (PTS) for cruciate-retaining (CR) total knee arthroplasty (TKA) is usually pre-determined by the surgeon. Limited information is available comparing different choices of PTS on the kinematics of the CR TKA, independent of the balancing of the extension gap. This study hypothesized that with the same balanced extension gap, the choice of PTS significantly impacts the intraoperatively measured kinematics of CR TKA. Navigated CR TKAs were performed on seven fresh-frozen cadavers with healthy knees and intact posterior cruciate ligament (PCL). A custom designed tibial baseplate was implanted to allow in situ modification of the PTS, which altered the flexion gap but maintained the extension gap. Knee kinematics were measured by performing passive range of motion (ROM) tests from full extension to 120° of flexion on the intact knee and CR TKAs with four different PTSs (1°, 4°, 7°, and 10°). The measured kinematics were compared across test conditions to assess the impact of PTS. With a consistent extension gap, the change of PTS had significant impact on the anteroposterior (AP) kinematics of the CR TKA knees in mid-flexion range (45°-90°), but not so much for the high-flexion range (90°-120°). No considerable impacts were found on internal/external (I/E) rotation and hip-knee-ankle (HKA) angle. However, the findings on the individual basis suggested the impact of PTS on I/E rotation and HKA angle may be patient-specific. The data suggested that the choice of PTS had the greatest impact on the mid-flexion AP translation among the intraoperatively measured kinematics. This impact may be considered while making surgical decisions in the context of AP kinematics. When using a tibial component designed with "center" pivoting PTS, a surgeon may be able to fine tune the PTS to achieve proper mid-flexion AP stability.

  15. Elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

    Science.gov (United States)

    Turhan, Egemen; Ege, Ahmet; Keser, Selcuk; Bayar, Ahmet

    2008-10-01

    Elephantiasis nostras verrucosa represents an infrequent clinical entity with cutaneous changes characterized by dermal fibrosis, hyperkeratotic verrucous and papillamotous lesions resulting from chronic non-filarial lymphedema secondary to infections, surgeries, tumor obstruction, radiation, congestive heart failure, and obesity. Although recurrent streptococcal lymphangitis is believed to play a critical role in the origin of elephantiasis nostras verrucosa, the exact pathogenesis of the disorder is not yet clear. Therapeutic efforts should aim to reduce lymph stasis, which will also lead to improvement of the cutaneous changes but unfortunately there is no specific treatment for advanced cases. In this report, we present a patient who was treated by below knee amputation as a result of elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

  16. Double segmental tibial fractures - an unusual fracture pattern

    Directory of Open Access Journals (Sweden)

    Bali Kamal

    2012-02-01

    Full Text Available 【Abstract】A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech- nique with a pleasing outcome. Key words: Fracture, bone; Tibia; Fibula; Nails

  17. Age variations in the properties of human tibial trabecular bone

    DEFF Research Database (Denmark)

    Ding, Ming; Dalstra, M; Danielsen, CC

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...... strain and failure energy showed maxima at younger ages. These age-related variations (except for failure energy) were non-linear. Tissue density and mineral concentration were constant throughout life, whereas apparent density (the amount of bone) varied with ultimate stress. Collagen density (the...... amount of collagen) varied with failure energy. Collagen concentration was maximal at younger ages but varied little with age. Our results suggest that the decrease in mechanical properties of trabecular bone such as Young's modulus and ultimate stress is mainly a consequence of the loss of trabecular...

  18. Evaluation of wedge-shaped phantoms for assessment of scanner display as a part of quality control of scanner performance

    International Nuclear Information System (INIS)

    Bergmann, H.; Havlik, E.

    1981-01-01

    Image manipulation in modern rectilinear scanners comprises background subtraction and contrast enhancement facilities. It has been the aim of this investigation to develop simple quality assurance methods suitable for checking the function of these features on a routine basis. Several types of phantoms have been investigated: an absorption step wedge, an emission step wedge and an emission continuous wedge. The absorption step wedge when used with a usual gamma-camera checking source gave the least satisfactory results. The emission step wedge is best suited for test procedures for background subtraction of the colour printer display and for contrast enhancement of the photo display, whereas the emission continuous wedge gave best results in testing the contrast enhancement of the colour printer display. An evaluation of the relative merits of the phantoms indicates that the emission step wedge is best suited for quality assurance tests. (author)

  19. Effect of step width manipulation on tibial stress during running.

    Science.gov (United States)

    Meardon, Stacey A; Derrick, Timothy R

    2014-08-22

    Narrow step width has been linked to variables associated with tibial stress fracture. The purpose of this study was to evaluate the effect of step width on bone stresses using a standardized model of the tibia. 15 runners ran at their preferred 5k running velocity in three running conditions, preferred step width (PSW) and PSW±5% of leg length. 10 successful trials of force and 3-D motion data were collected. A combination of inverse dynamics, musculoskeletal modeling and beam theory was used to estimate stresses applied to the tibia using subject-specific anthropometrics and motion data. The tibia was modeled as a hollow ellipse. Multivariate analysis revealed that tibial stresses at the distal 1/3 of the tibia differed with step width manipulation (p=0.002). Compression on the posterior and medial aspect of the tibia was inversely related to step width such that as step width increased, compression on the surface of tibia decreased (linear trend p=0.036 and 0.003). Similarly, tension on the anterior surface of the tibia decreased as step width increased (linear trend p=0.029). Widening step width linearly reduced shear stress at all 4 sites (pstresses experienced by the tibia during running were influenced by step width when using a standardized model of the tibia. Wider step widths were generally associated with reduced loading of the tibia and may benefit runners at risk of or experiencing stress injury at the tibia, especially if they present with a crossover running style. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Comparison of CT and MRI in patients with tibial plateau fracture: can CT findings predict ligament tear or meniscal injury?

    International Nuclear Information System (INIS)

    Mui, Leonora W.; Engelsohn, Eliyahu; Umans, Hilary

    2007-01-01

    (1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury. A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion. CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap and articular depression was significantly greater in patients with meniscal injury compared with those without meniscal injury, ROC analysis demonstrated no clear threshold for gap or depression that yielded a combination of high sensitivity and specificity. In the acute setting, CT offers high sensitivity and specificity for depicting osseous avulsions, as well as high negative predictive value for excluding ligament injury. However, MRI remains necessary for the preoperative detection of meniscal injury. (orig.)

  1. Enhanced dynamic wedge and independent monitor unit verification

    International Nuclear Information System (INIS)

    Howlett, SJ.

    2005-01-01

    Some serious radiation accidents have occurred around the world during the delivery of radiotherapy treatment. The regrettable incident in Panama clearly indicated the need for independent monitor unit (MU) verification. Indeed the International Atomic Energy Agency (IAEA), after investigating the incident, made specific recommendations for radiotherapy centres which included an independent monitor unit check for all treatments. Independent monitor unit verification is practiced in many radiotherapy centres in developed countries around the world. It is mandatory in USA but not yet in Australia. This paper describes development of an independent MU program, concentrating on the implementation of the Enhanced Dynamic Wedge (EDW) component. The difficult case of non centre of field (COF) calculation points under the EDW was studied in some detail. Results of a survey of Australasian centres regarding the use of independent MU check systems is also presented. The system was developed with reference to MU calculations made by Pinnacle 3 D Radiotherapy Treatment Planning (RTP) system (ADAC - Philips) for 4MV, 6MV and 18MV X-ray beams used at the Newcastle Mater Misericordiae Hospital (NMMH) in the clinical environment. A small systematic error was detected in the equation used for the EDW calculations. Results indicate that COF equations may be used in the non COF situation with similar accuracy to that achieved with profile corrected methods. Further collaborative work with other centres is planned to extend these findings

  2. Canonical quantization of the Proca field in the Rindler wedge

    International Nuclear Information System (INIS)

    Castineiras, Jorge; Correa, Emerson Benedito Sousa; Crispino, Luis Carlos Bassalo; Matsas, George Emanuel Avraam

    2009-01-01

    Full text. We perform the canonical quantization of a massive vector field in Rindler spacetime. We pay special attention to the zero frequency modes of the Proca field because these are the modes that interact with structureless sources which are static in the Rindler spacetime. Our motivation is the computation of the total response of a static source with some fixed proper acceleration a 0 in Rindler spacetime interacting with the zero energy massive vector particle of the Fulling-Davies-Unruh (FDU) thermal bath and compare it with the response of a static source with the same proper acceleration a 0 outside a Schwarzschild black hole interacting with the massive vector particles of the Hawking thermal radiation. Surprisingly, as it was already shown in a resent article, these responses would be identical if a massless scalar field is consider instead of the massive vector field, the field outside the Schwarzschild black hole is supposed to be in the Unruh vacuum and the source proper acceleration is the same in both cases. This came as a surprise because structureless static sources can only interact with zero-frequency field modes. Such modes can probe the global geometry of spacetime and are accordingly quite different in Schwarzschild spacetime and in the Rindler wedge. (author)

  3. Treatment preferences in Turkey for open fracture of the tibial diaphysis

    Directory of Open Access Journals (Sweden)

    Güzelali Özdemir

    2017-03-01

    Conclusion: A wide variation was observed among orthopedics and traumatology specialists in Turkey regarding treatment of open tibial diaphysis fracture in adults. Data obtained from this study together with the available literature may be useful to further develop therapeutic approaches.

  4. Study of the anatomy of the tibial nerve and its branches in the distal medial leg

    Science.gov (United States)

    Torres, André Leal Gonçalves; Ferreira, Marcus Castro

    2012-01-01

    Objective Determine, through dissection in fresh cadavers, the topographic anatomy of the tibial nerve and its branches at the ankle, in relation to the tarsal tunnel. Methods Bilateral dissections were performed on 26 fresh cadavers and the locations of the tibial nerve bifurcation and its branches were measured in millimeters. For the calcaneal branches, the amount and their respective nerves of origin were also analyzed. Results The tibial nerve bifurcation occurred under the tunnel in 88% of the cases and proximally in 12%. As for the calcaneal branches, the medial presented with one (58%), two (34%) and three (8%) branches, with the most common source occurring in the tibial nerve (90%) and the lower with a single branch per leg and lateral plantar nerve as the most common origin (70%). Level of Evidence, V Expert opinion. PMID:24453596

  5. What is the optimal alignment of the tibial and femoral components in knee arthroplasty?

    DEFF Research Database (Denmark)

    Gromov, Kirill; Korchi, Mounim; Thomsen, Morten G

    2014-01-01

    of positioning on survival and functional outcome was considered. Results - Many definitions exist when evaluating placement of femoral and tibial components. Implant alignment plays a role in both survival and functional outcome following primary TKA, as component malalignment can lead to increased failure......Background - Surgeon-dependent factors such as optimal implant alignment are thought to play a significant role in outcome following primary total knee arthroplasty (TKA). Exact definitions and references for optimal alignment are, however, still being debated. This overview of the literature...... describes different definitions of component alignment following primary TKA for (1) tibiofemoral alignment in the AP plane, (2) tibial and femoral component placement in the AP plane, (3) tibial and femoral component placement in the sagittal plane, and (4) rotational alignment of tibial and femoral...

  6. Effect of lateral release and tibial tuberosity transposition on the patellar tilt analyzed by MRI

    International Nuclear Information System (INIS)

    Koskinen, S.; Kormano, M.; Kujala, U.M.; Research Institute for Sports and Exercise Medicine, Helsinki; City Hospital, Turku

    1990-01-01

    The preliminary results are presented from studies in which MRI techniques are used to analyze the effect of lateral release and tibial tuberosity transposition procedures on the patellofemoral relationships. (author). 4 refs.; 1 fig.; 1 tab

  7. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter.

    Science.gov (United States)

    Al Kaissi, Ali; Ganger, Rudolf; Klaushofer, Klaus; Grill, Franz

    2014-01-01

    Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD) inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  8. Quantitative Comparison of the Microscopic Anatomy of the Human ACL Femoral and Tibial Entheses

    Science.gov (United States)

    Beaulieu, Mélanie L.; Carey, Grace E.; Schlecht, Stephen H.; Wojtys, Edward M.; Ashton-Miller, James A.

    2015-01-01

    The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p fibrocartilage tissue area (p fibrocartilage depth (p fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. PMID:26134706

  9. Management of tibial fractures using a circular external fixator in two calves.

    Science.gov (United States)

    Aithal, Hari Prasad; Kinjavdekar, Prakash; Amarpal; Pawde, Abhijit Motiram; Singh, Gaj Raj; Setia, Harish Chandra

    2010-07-01

    To report the repair of tibial diaphyseal fractures in 2 calves using a circular external skeletal fixator (CEF). Clinical report. Crossbred calves (n=2; age: 6 months; weight: 55 and 60 kg). Mid-diaphyseal tibial fractures were repaired by the use of a 4-ring CEF (made of aluminum rings with 2 mm K-wires) alone in 1 calf and in combination with hemicerclage wiring in 1 calf. Both calves had good weight bearing with moderate lameness postoperatively. Fracture healing occurred by day 60 in 1 calf and by day 30 in calf 2. The CEF was well maintained and tolerated by both calves through fracture healing. Joint mobility and limb usage improved gradually after CEF removal. CEF provided a stable fixation of tibial fractures and healing within 60 days and functional recovery within 90 days. CEF can be safely and successfully used for the management of selected tibial fractures in calves.

  10. Measurement of dynamic wedge angles and beam profiles by means of MRI ferrous sulphate gel dosimetry

    Science.gov (United States)

    Bengtsson, Magnus; Furre, Torbjørn; Rødal, Jan; Skretting, Arne; Olsen, Dag R.

    1996-02-01

    The purpose of this study is to examine the possible value of measuring the dose distribution in dynamic wedge photon beams using ferrous sulphate gel phantoms analysed by MRI. The wedge angles and dose profiles were measured for a field size of and for dynamic wedge angles of , , and using a 15 MV photon beam generated from a Clinac 2100 CD (Varian). The dose profiles obtained from MRI ferrous sulphate gel were in good agreement with the dose measurements performed with a diode detector array. Also, the wedge angles determined from the MRI ferrous sulphate gel agreed well with the values obtained by using film dosimetry and with calculations by use of TMS (treatment planning system) (Helax, Uppsala, Sweden). The study demonstrated that MRI ferrous sulphate gel dosimetry is an adequate tool for measurements of some beam characteristics of dynamic radiation fields.

  11. Reduced emissions of greenhouse gases 2050: Technological wedges - Input to the Commission on Low Emissions

    International Nuclear Information System (INIS)

    Rosenberg, Eva; Espegren, Kari Aamodt; Finden, Per; Hageman, Rolf; Stenersen, Dag

    2006-09-01

    The Commission on Low Emissions was established in March 2005 and has been charged with the task of describing how Norway can achieve a 50-80 percent reduction in emissions of greenhouse gases by 2050. The commission describes the desired total reduction in emissions to be a set of actions or 'wedges', meaning that the reduction in emissions are linked to an array of technological and behavioural changes. The technological wedges are described here, while the behavioural wedges are treated in a different report. The potentials described are based on the Low Emission's reference line. Possible changes in the reference line will result in changed potentials. The technological wedges studied comprise to a great extent a potential of 50-80 percent reduction in greenhouse gases by 2050. This depends on considerable effort from research and development, and a determination to change external conditions

  12. Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’s vertical displacement soon after the wedge-clad contact resistance is initiated.

  13. Diffraction of an inhomogeneous plane wave by an impedance wedge in a lossy medium

    CSIR Research Space (South Africa)

    Manara, G

    1998-11-01

    Full Text Available The diffraction of an inhomogeneous plane wave by an impedance wedge embedded in a lossy medium is analyzed. The rigorous integral representation for the field is asymptotically evaluated in the context of the uniform geometrical theory...

  14. Acute simultaneous bilateral avulsion fractures of the tibial tubercles in a 15-year-old male hurler: case report and literature review.

    LENUS (Irish Health Repository)

    Hanley, C

    2012-02-01

    BACKGROUND: Avulsion fractures of the tibial tubercle are an unusual injury pattern generally occurring in the adolescent male during sporting activities. Bilateral simultaneous fractures are extremely rare. They are often associated with other underlying orthopaedic pathology. AIMS: We present a case of bilateral tibial tubercle avulsions occurring in a 15 year-old male hurler. We describe the management and necessary investigations required for this type of trauma and present a literature review on this rarely encountered injury. CONCLUSION: Although this type of atypical fracture pattern is associated with high energy trauma and other underlying pathology, we have shown that once treated, the patient can expect to make a prompt return to sporting activities with no significant long-term functional deficit.

  15. Evidence of Arc Magma Genesis in a Paleo-Mantle Wedge, the Higashi-Akaishi Peridotite, Japan

    Science.gov (United States)

    Till, C. B.; Guild, M. R.; Grove, T. L.; Carlson, R. W.

    2014-12-01

    Located in the Sanbagawa subduction-related high-pressure metamorphic belt in SW Japan on the island of Shikoku, the Higashi-akaishi peridotite body is composed of dunite, lherzolite and garnet clinopyroxenite, interfingered in one locality with quartz-rich eclogite. Previous work indicates the P-T history of the peridotite includes rapid prograde metamorphism with peak temperatures of 700-810°C and pressures of 2.9-3.8 GPa [1] at ~88-89 Ma followed by rapid exhumation at >2.5 cm/yr [2,3]. Major and trace element and isotopic data from samples within the Higashi-akaishi peridotite presented here and in another recent study [4] provide a record of subduction zone melting processes in a paleo-mantle wedge. Ultramafic samples range from 40-52 wt.% SiO2, 1-11 wt.% Al2O3 and 21-45 wt.% MgO with olivine and clinopyroxene Mg#'s as high as 0.93. The quartz-rich eclogite contains 62 wt.% SiO2, 6 wt.% MgO and 13 wt.% Al2O3 with trace element concentrations that are enriched relative to the ultramafic samples. 87Sr/86Sr (.703237-.704288), 143Nd/144Nd (ɛNd=+2 to +6) and Pb isotopic compositions are within the range of previously studied Japanese arc rocks. We interpret the pyroxenites as shallowly crystallized cumulates with varying amounts of trapped hydrous melt and the harzburgites as residues of melting. The peak P-T conditions of these rocks are similar to the solidus conditions of H2O-saturated fertile mantle near the base of the mantle wedge [5,6]. The presence of garnet porphyroblasts that enclose primary euhedral chlorite together with the chemical evidence, suggest these samples are associated with mantle melting in the presence of H2O. Major element modeling suggests the quartz-rich eclogite composition can be reproduced through mixing melts of subducted sediment with wet peridotite melts in the mantle wedge. Thus the Higashi-aikashi rock suite provides an in-situ record of the beginnings of hydrous melting and the mechanisms of metasomatism in the mantle wedge

  16. Effect of Icariin on Tibial Dyschondroplasia Incidence and Tibial Characteristics by Regulating P2RX7 in Chickens

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2018-01-01

    Full Text Available Tibial dyschondroplasia (TD is a disease of rapid growing chickens that occurs in many avian species; it is characterized by nonvascular and nonmineralized growth plates, along with tibia bone deformation and lameness. Icariin is widely used to treat bone diseases in humans, but no report is available regarding the effectiveness of icariin against avian TD. Therefore, this study was designed to determine its effect against TD. For this purpose, a total of 180 broiler chicks were distributed into three groups including control, TD, and icariin group. Control group was given a standard normal diet, while TD and icariin groups received normal standard diet containing 50 mg/kg thiram to induce TD from days 3 to 7 after hatch. After the induction of TD, the chicks of icariin group were fed with standard normal diet by adding 10 mg/kg icariin in water. Then morphological and production parameters analysis of tibial bone indicators, physiological index changes, and gene expression were examined. The results showed that icariin administration not only decreased the mortality but also mitigated the lameness and promoted the angiogenesis, which diminished the TD lesion and significantly increased the expression of P2RX7 (P<0.05 in TD affected thiram induced chicks. In conclusion, present findings suggest that icariin has a significant role in promoting the recovery of chicken growth plates affected by TD via regulating the P2RX7. Our findings reveal a new target for clinical treatment and prevention of TD in broiler chickens.

  17. Ground reaction forces and bone parameters in females with tibial stress fracture.

    Science.gov (United States)

    Bennell, Kim; Crossley, Kay; Jayarajan, Jyotsna; Walton, Elizabeth; Warden, Stuart; Kiss, Z Stephen; Wrigley, Tim

    2004-03-01

    Tibial stress fracture is a common overuse running injury that results from the interplay of repetitive mechanical loading and bone strength. This research project aimed to determine whether female runners with a history of tibial stress fracture (TSF) differ in ground reaction force (GRF) parameters during running, regional bone density, and tibial bone geometry from those who have never sustained a stress fracture (NSF). Thirty-six female running athletes (13 TSF; 23 NSF) ranging in age from 18 to 44 yr were recruited for this cross-sectional study. The groups were well matched for demographic, training, and menstrual parameters. A force platform measured selected GRF parameters (peak and time to peak for vertical impact and active forces, and horizontal braking and propulsive forces) during overground running at 4.0 m.s.(-1). Lumbar spine, proximal femur, and distal tibial bone mineral density were assessed by dual energy x-ray absorptiometry. Tibial bone geometry (cross-sectional dimensions and areas, and second moments of area) was calculated from a computerized tomography scan at the junction of the middle and distal thirds. There were no significant differences between the groups for any of the GRF, bone density, or tibial bone geometric parameters (P > 0.05). Both TSF and NSF subjects had bone density levels that were average or above average compared with a young adult reference range. Factor analysis followed by discriminant function analysis did not find any combinations of variables that differentiated between TSF and NSF groups. These findings do not support a role for GRF, bone density, or tibial bone geometry in the development of tibial stress fractures, suggesting that other risk factors were more important in this cohort of female runners.

  18. Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty

    OpenAIRE

    Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

    2016-01-01

    A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed...

  19. All-Polyethylene Tibial Components: An Analysis of Long-Term Outcomes and Infection.

    Science.gov (United States)

    Houdek, Matthew T; Wagner, Eric R; Wyles, Cody C; Watts, Chad D; Cass, Joseph R; Trousdale, Robert T

    2016-07-01

    There is debate regarding tibial component modularity and composition in total knee arthroplasty (TKA). Biomechanical studies have suggested improved stress distribution in metal-backed tibias; however, these results have not translated clinically. The purpose of this study was to analyze the outcomes of all-polyethylene components and to compare the results to those with metal-backed components. We reviewed 31,939 patients undergoing a primary TKA over a 43-year period (1970-2013). There were 28,224 (88%) metal-backed and 3715 (12%) all-polyethylene tibial components. The metal-backed and all-polyethylene groups had comparable demographics with respect to gender, age and body mass index (BMI). Mean follow-up was 7 years. The mean survival for all primary TKAs at the 5-, 10-, 20- and 30-year time points was 95%, 89%, 73%, and 57%, respectively. All-polyethylene tibial components were found to have a significantly improved (P tibial components were also found to have a significantly lower rate of infection, instability, tibial component loosening, and periprosthetic fracture. The all-polyethylene group had improved survival rates in all age groups, except in patients 85 years old or greater, where there was no significant difference. All-polyethylene tibial components had improved survival for all BMI groups except in the morbidly obese (BMI ≥ 40) where there was no significant difference. All-polyethylene tibial components had significantly improved implant survival, reduced rates of postoperative infection, fracture, and tibial component loosening. All polyethylene should be considered for most of the patients, regardless of age and BMI. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Comparison of long-term results between osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

    Science.gov (United States)

    Charoenrook, Victor; Michael, Ralph; de la Paz, Maria Fideliz; Temprano, José; Barraquer, Rafael I

    2018-04-01

    To compare the anatomical and the functional results between osteo-odonto-keratoprosthesis (OOKP) and keratoprosthesis using tibial bone autograft (Tibial bone KPro). We reviewed the charts of 258 patients; 145 had OOKP whereas 113 had Tibial bone KPro implanted. Functional success was defined as best corrected visual acuity ≥0.05 on decimal scale and anatomical success as retention of the keratoprosthesis lamina. Kaplan-Meier survival curves were calculated for anatomical and functional survival as well as to estimate the probability of post-op complications. The anatomical survival for both KPro groups was not significantly different and was estimated as 67% for OOKP and 54% for Tibial bone KPro at 10 years after surgery. There was also no difference found after subdividing for primary diagnosis groups such as chemical injury, thermal burn, trachoma and all autoimmune cases combined. Estimated functional survival at 10 years post-surgery was 49% for OOKP and 25% for Tibial bone KPro, which was significantly different. The probability of patients with Tibial bone KPro developing one or more post-operative complications at 10 years after surgery (65%) was significantly higher than those with OOKP (40%). Mucous membrane necrosis and retroprosthetic membrane formation were more common in Tibial bone KPro than OOKP. Both types of autologous biological KPro, OOKP and Tibial bone KPro, had statistically similar rate of keratoprosthesis extrusion. Although functional success rate was significantly higher in OOKP, it may have been influenced by a better visual potential in the patients in this group. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

    Science.gov (United States)

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-06-01

    Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with achondroplasia. We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence-especially when lengthening of more than 50% is attempted.

  2. SIMULTANEOUS BILATERAL AVULSION FRACTURE OF THE TIBIAL TUBEROSITY IN A TEENAGER: CASE REPORT AND THERAPY USED.

    Science.gov (United States)

    E Albuquerque, Rodrigo Pires; Giordano, Vincenzo; Carvalho, Antônio Carlos Pires; Puell, Thiago; E Albuquerque, Maria Isabel Pires; do Amaral, Ney Pecegueiro

    2012-01-01

    Simultaneous bilateral avulsion fracture of the tibial tuberosity in teenagers is a rare lesion. We describe the first case in the literature, in a teenage girl who sustained a fall while jumping during a volleyball match. No predisposing factors were iden tified. The lesions were treated with open surgical reduction and internal fixation. The aim of the present study was to present a case of simultaneous bilateral avulsion fracture of the tibial tuberosity in a teenage girl and the therapy used.

  3. Locking plate fixation in distal metaphyseal tibial fractures: series of 79 patients

    OpenAIRE

    Gupta, Rakesh K.; Rohilla, Rajesh Kumar; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

    2009-01-01

    Open reduction and internal fixation in distal tibial fractures jeopardises fracture fragment vascularity and often results in soft tissue complications. Minimally invasive osteosynthesis, if possible, offers the best possible option as it permits adequate fixation in a biological manner. Seventy-nine consecutive adult patients with distal tibial fractures, including one patient with a bilateral fracture of the distal tibia, treated with locking plates, were retrospectively reviewed. The 4.5-...

  4. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments

    OpenAIRE

    Franklyn, Melanie; Oakes, Barry

    2015-01-01

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imagin...

  5. Complex Medial Meniscus Tears Are Associated With a Biconcave Medial Tibial Plateau.

    Science.gov (United States)

    Barber, F Alan; Getelman, Mark H; Berry, Kathy L

    2017-04-01

    To determine whether an association exists between a biconcave medial tibial plateau and complex medial meniscus tears. A consecutive series of stable knees undergoing arthroscopy were evaluated retrospectively with the use of preoperative magnetic resonance imaging (MRI), radiographs, and arthroscopy documented by intraoperative videos. Investigators independently performed blinded reviews of the MRI or videos. Based on the arthroscopy findings, medial tibial plateaus were classified as either biconcave or not biconcave. A transverse coronal plane ridge, separating the front of the tibial plateau from the back near the inner margin of the posterior body of the medial meniscus, was defined as biconcave. The medial plateau slope was calculated with MRI sagittal views. General demographic information, body mass index, and arthroscopically confirmed knee pathology were recorded. A total of 179 consecutive knees were studied from July 2014 through August 2015; 49 (27.2%) biconcave medial tibial plateaus and 130 (72.8%) controls were identified at arthroscopy. Complex medial meniscus tears were found in 103. Patients with a biconcave medial tibial plateau were found to have more complex medial meniscus tears (69.4%) than those without a biconcavity (53.1%) (P = .049) despite having lower body mass index (P = .020). No difference in medial tibial plateau slope was observed for biconcavities involving both cartilage and bone, bone only, or an indeterminate group (P = .47). Biconcave medial tibial plateaus were present in 27.4% of a consecutive series of patients undergoing knee arthroscopy. A biconcave medial tibial plateau was more frequently associated with a complex medial meniscus tear. Level III, case-control study. Copyright © 2016 Arthroscopy Association of North America. All rights reserved.

  6. Wedge and subselective pulmonary angiography in pulmonary hypertension secondary to venous obstruction

    International Nuclear Information System (INIS)

    Bowen, J.S.; Bookstein, J.J.; Johnson, A.D.; Peterson, K.L.; Moser, K.M.

    1985-01-01

    Pulmonary wedge or subselective angiography provided key diagnostic information in two cases of pulmonary hypertension secondary to pulmonary venous obstruction. Whereas conventional pulmonary angiograms and ventilation-perfusion lung scans were interpreted as showing embolism, plain radiographs demonstrated Kerley B lines, suggesting venous obstruction. Subselective or wedge angiography of nonopacified arteries verified their anatomical patency and also revealed venous stenoses, collaterals, and atrophy indicative of obstruction

  7. Improved field abutment-wedge design for 6-MV x-rays

    International Nuclear Information System (INIS)

    Nyerick, C.E.; Steadham, R.E.

    1989-01-01

    This paper presents an improved abutment wedge for matching large photon fields. The wedge is used with a 6-MV Linac accelerator and generates a 5-cm pseudopenumbra at the 50% relative dose juncture. The features allow treatment of fields up to 40 cm long in any fractional step of increment, simultaneous generation of two wide penumbrae or one wide and one sharp penumbra, and attachment of the device downstream of standard beam-shaping accessories in any 90 degrees angular orientation

  8. B-type olivine fabric induced by low temperature dissolution creep during serpentinization and deformation in mantle wedge

    Science.gov (United States)

    Liu, Wenlong; Zhang, Junfeng; Barou, Fabrice

    2018-01-01

    The B-type olivine fabric (i.e., the [010] axes subnormal to foliation and the [001] axes subparallel to the lineation) has been regarded as an important olivine fabric for interpreting global trench-parallel S-wave polarization in fore-arc regions. However, strong serpentinization and cold temperature environment in the mantle wedge should inhibit development of the B-type olivine fabric that requires high temperature to activate solid-state plastic deformation. Here we report fabrics of olivine and antigorite generated at low temperatures (300-370 °C) during serpentinization in a fossil mantle wedge of the Val Malenco area, Central Alps. Olivine in the serpentine matrix develops a pronounced B-type fabric, while antigorite in the same matrix displays a strong crystallographic preferred orientation (CPO) with the (001) planes and the [010] axes subparallel to foliation and lineation, respectively. The following evidence leads to the conclusion that the B-type olivine fabric results from dissolution creep assisted by grain boundary sliding (GBS) and grain rotation, rather than solid-state plastic deformation: (1) serpentinization took place at low temperatures and a fluid-enriched environment, ideal for dissolution-precipitation creep; (2) the voids and zigzag boundaries along the interface between antigorite and olivine suggest a fluid dissolution reaction; (3) the primary coarse olivine develops a nearly random fabric, indicating the B-type fabrics in the fine-grained olivine may not be inherited fabrics. These results document for the first time the B-type olivine CPO formed by dissolution creep at low temperatures during serpentinization and provide a mechanism to reconcile petrofabric observations with geophysical observations of trench parallel fast S-wave seismic anisotropy in fore-arc mantle wedge regions.

  9. Low temperature dissolution creep induced B-type olivine fabric during serpentinization and deformation in mantle wedge

    Science.gov (United States)

    Liu, W.; Zhang, J.

    2017-12-01

    The B-type olivine fabric (i.e., the [010]ol axes subnormal to foliation and the [001]ol axes subparallel to the lineation) has been regarded as an important olivine fabric for interpreting global trench-parallel S-wave polarization in fore-arc regions. However, strong serpentinization and cold temperature environment in the mantle wedge should inhibit development of the B-type olivine fabric that requires high temperature to activate solid-state plastic deformation. Here we report fabrics of olivine and antigorite generated at low temperatures (300-370 oC) during serpentinization in a fossil mantle wedge of the Val Malenco area, Central Alps. Olivine in the serpentine matrix develops a pronounced B-type fabric, while antigorite in the same matrix displays a strong crystallographic orientation (CPO) with the (001) and the [010] subparallel to foliation and lineation, respectively. The following evidence leads to the conclusion that the B-type olivine fabric is resulted from dissolution creep assisted by grain boundaries sliding (GBS) and grain rotation, rather than solid-state plastic deformation: (1) serpentinization took place at low temperatures and a fluid-enriched environment, ideal for dissolution-precipitation creep; (2) the voids and zigzag boundaries along the interface between antigorite and olivine suggest a fluid dissolution reaction; (3) the primary coarse olivine develops a nearly random fabric, indicating the B-type fabrics in the fine-grained olivine can't be inherited fabrics. These results document for the first time the B-type olivine CPO formed by dissolution creep at low temperatures during serpentinization and provide a mechanism to reconcile petrofabric observations with geophysical observations of trench parallel fast S-wave seismic anisotropy in fore-arc mantle wedge regions.

  10. Angular stable plates in proximal meta-epiphyseal tibial fractures: study of joint restoration and clinical and functional evaluation.

    Science.gov (United States)

    Giannotti, S; Giovannelli, D; Dell'Osso, G; Bottai, V; Bugelli, G; Celli, F; Citarelli, C; Guido, G

    2016-04-01

    The tibial plateau fractures involve one of the main weight bearing joints of the human body. The goals of surgical treatment are anatomical reduction, articular surface reconstruction and high primary stability. The aim of this study was to evaluate the clinical and functional outcomes after internal plate fixation of this kind of fractures. From January 2009 to December 2012, we treated 75 cases of tibial plateau fracture with angular stable plates. We used Rasmussen Score and the Knee Society Score for the clinical and functional evaluation. Twenty-five cases that underwent hardware removal had arthroscopic and CT evaluation of the joint. No complications occurred. The clinical and functional evaluation, performed by the KSS and Rasmussen Score, highlighted the high percentage of good-to-excellent results (over 90 %). In every case, the range of motion was good with flexion >90°. Arthroscopy showed the presence of chondral damage in 100 % of patients. In all the cases, we found that X-ray images seem better than the CT images. Angular stable plates allow to obtain a good primary stability, permitting an early joint recovery with an excellent range of motion. Avoiding to perform a knee arthrotomy at the time of fracture reduction could prove to be an advantage in terms of functional recovery. The meniscus on the injured bone should be preserved in order to maintain good function of the joint. X-ray images remain the gold standard in checking the progression of post-traumatic osteoarthritis.

  11. The application of wedge type compensation filter for uniform density on the endoscopic retrograde pancreatography

    International Nuclear Information System (INIS)

    Son, Soon Yong; Lee, Hee Jeong; Lee, Won Hong; Cho, Cheong Chan; Ryu, Meung Sun; Jung, Hong Ryang

    2001-01-01

    Over-density of pancreatic duct tail part on the endoscopic retrograde pancreatogram results from patient's position and inserted air during the study. The aim of this paper is to decide the filter angle to obtain an uniform density. Endoscopic retrograde pancratography was performed to 234 patients, and angled wedge filter was used differently. They are 10 deg (47), 20 deg (45), 30 deg (50). We also did not use wedge filter to 42 patients. We decided reliance degree in 95%. The statistical difference was p<0.05. The patients' sex rate was 1.8:1 between 18 and 87 years old(average age 58 years). Their body girth was 18.71 cm on the average. Of total 234 patients, difference of right and left average density was 0.01 by 30 deg wedge filter, -0.08 40 deg wedge filter and 0.27 non-wedge filter. These average values of difference density were very significant statistically, and standard deviation also was close to regular distribution. In conclusion, there is a usefulness of angled wedge filter for increasing diagnostic value of pancreatic duct tail part on the endoscopic retrograde pancreatogram

  12. Porous Titanium Wedges in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity.

    Science.gov (United States)

    Moore, Spencer H; Carstensen, S Evan; Burrus, M Tyrrell; Cooper, Truitt; Park, Joseph S; Perumal, Venkat

    2017-10-01

    Lateral column lengthening (LCL) is a common procedure for reconstruction of stage II flexible adult-acquired flatfoot deformity (AAFD). The recent development of porous titanium wedges for this procedure provides an alternative to allograft and autograft. The purpose of this study was to report radiographic and clinical outcomes achieved with porous titanium wedges in LCL. A retrospective analysis of 34 feet in 30 patients with AAFD that received porous titanium wedges for LCL from January 2011 to October 2014. Deformity correction was assessed using both radiographic and clinical parameters. Radiographic correction was assessed using the lateral talo-first metatarsal angle, the talonavicular uncoverage percentage, and the first metatarsocuneiform height. The hindfoot valgus angle was measured. Patients were followed from a minimum of 6 months up to 4 years (mean 16.1 months). Postoperative radiographs demonstrated significant correction in all 3 radiographic criteria and the hindfoot valgus angle. We had no cases of nonunion, no wedge migration, and no wedges have been removed to date. The most common complication was calcaneocuboid joint pain (14.7%). Porous titanium wedges in LCL can achieve good radiographic and clinical correction of AAFD with a low rate of nonunion and other complications. Level IV: Case series.

  13. On the practice of the clinical implementation of enhanced dynamic wedges

    International Nuclear Information System (INIS)

    Koken, Phil W.; Heukelom, Stan; Cuijpers, Johan P.

    2003-01-01

    Practical aspects of the clinical implementation of enhanced dynamic wedges (EDW) replacing manual wedges are presented and discussed extensively. A comparison between measured and calculated data is also presented. Relative dose distributions and wedge factors were calculated with a commercially available treatment planning system and measured in a water-phantom and with an ionization chamber. Wedge factor calculations and measurements were also compared with an independent method of wedge factor calculations available from the literature. Aspects of the clinical implementation, such as safety and quality assurance, were evaluated. Measurements and calculations agreed very well and were slightly better than results of previous studies. Profiles and percentage depth doses (PDDs) agreed within 1% to 1.5% and within 0.5%, respectively. Measured and calculated wedge factors ratios agreed within 0.5% to 1%. Calculated and measured EDW dose distributions showed excellent agreement, both relative and absolute. However, for safe and practical use, specific aspects need to be taken into consideration. Once the treatment planning system is commissioned properly, the clinical implementation of EDW is rather straightforward

  14. Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners.

    Science.gov (United States)

    Chen, T L; An, W W; Chan, Z Y S; Au, I P H; Zhang, Z H; Cheung, R T H

    2016-03-01

    Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture. Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability. Heelstrike runners experienced greater impact loading immediately after landing pattern switch (Ptibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986). Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Passive Posterior Tibial Subluxation on Routine Knee MRI as a Secondary Sign of PCL Tear

    International Nuclear Information System (INIS)

    Degnan, A.J.; Adam, R.J.; Maldjian, C.; Harner, Ch.D.

    2014-01-01

    The posterior drawer test is an accurate clinical test to diagnose posterior cruciate ligament (PCL), indicating laxity of the PCL that allows posterior tibial translation. This study aimed to determine whether posterior tibial translation relative to the femur on routine MRI could serve as an additional sign of PCL tear. Routine knee MRI in eleven patients (7 males, 4 females) with arthroscopically confirmed isolated PCL tears were reviewed independently by two musculoskeletal radiologists. Measurements of tibial translation were made in the medial and lateral compartments of patients and controls (10 males, 12 females) without clinical or MRI evidence of ligament injury. Significant medial compartment posterior tibial translation was present in patients with PCL tear compared to controls (+2.93 mm versus +0.03 mm, Ρ=0.002) with excellent interobserver agreement (intraclass correlation coefficient (ICC) = 0.94). No significant difference in lateral compartment tibial translation was observed (+0.17 mm versus -0.57 mm, Ρ=0.366) despite excellent interobserver agreement (ICC = 0.96). Posterior tibial translation in the midmedial compartment may be a secondary sign of isolated PCL tear on routine knee MRI with passive extension without manipulation or weight bearing. Additional work in a larger cohort may better address the accuracy of this finding

  16. Acute changes in foot strike pattern and cadence affect running parameters associated with tibial stress fractures.

    Science.gov (United States)

    Yong, Jennifer R; Silder, Amy; Montgomery, Kate L; Fredericson, Michael; Delp, Scott L

    2018-05-18

    Tibial stress fractures are a common and debilitating injury that occur in distance runners. Runners may be able to decrease tibial stress fracture risk by adopting a running pattern that reduces biomechanical parameters associated with a history of tibial stress fracture. The purpose of this study was to test the hypothesis that converting to a forefoot striking pattern or increasing cadence without focusing on changing foot strike type would reduce injury risk parameters in recreational runners. Running kinematics, ground reaction forces and tibial accelerations were recorded from seventeen healthy, habitual rearfoot striking runners while running in their natural running pattern and after two acute retraining conditions: (1) converting to forefoot striking without focusing on cadence and (2) increasing cadence without focusing on foot strike. We found that converting to forefoot striking decreased two risk factors for tibial stress fracture: average and peak loading rates. Increasing cadence decreased one risk factor: peak hip adduction angle. Our results demonstrate that acute adaptation to forefoot striking reduces different injury risk parameters than acute adaptation to increased cadence and suggest that both modifications may reduce the risk of tibial stress fractures. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Local and Widespread Hyperalgesia After Isolated Tibial Shaft Fractures Treated with Intramedullary Nailing

    DEFF Research Database (Denmark)

    Larsen, Peter; Elsøe, Rasmus; Graven-Nielsen, Thomas

    2016-01-01

    OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months postopera...... fracture treated with intramedullary nailing, although no widespread (extrasegmental) hyperalgesia was detected. Such observations may be important for developing the most adequate rehabilitation procedure following a tibial fracture.......OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months...... postoperatively after intramedullary nailing of tibial shaft fracture. METHODS: A total of 39 patients were included in this 12-month follow-up study. After 6 weeks, 3, 6, and 12 months postoperatively the pain intensity was measured on a visual analog scale (VAS) and the pressure pain sensitivity was assessed...

  18. Locking internal fixator with minimally invasive plate osteosynthesis for the proximal and distal tibial fractures

    Directory of Open Access Journals (Sweden)

    TONG Da-ke

    2012-02-01

    Full Text Available 【Abstract】Objective: To investigate the efficacy of the locking internal fixator (LIF, which includes the locking compression plate (LCP and the less invasive stable system (LISS, in the proximal and distal tibial fractures. Methods: We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the opera- tion with LIF by the minimally invasive plate osteosynthesis (MIPO technique. The data consisted of 43 proximal tibial fractures (type AO41C3 and 55 distal tibial fractures (type AO43C3. Results: No complications were observed in all patients after operation. The mean healing time was 8.4 months (range 5-14 months. Only two cases of delayed union occurred at postoperative 10 months. No infections were reported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at postoperative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion: Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing. Key words: Internal fixator; Tibial fractures; Fracture fixation, intramedullary; Bone plates

  19. [The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement].

    Science.gov (United States)

    García David, S; Cortijo Martínez, J A; Navarro Bermúdez, I; Maculé, F; Hinarejos, P; Puig-Verdié, L; Monllau, J C; Hernández Hermoso, J A

    2014-01-01

    The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  20. Three-dimensional vertebral wedging in mild and moderate adolescent idiopathic scoliosis.

    Directory of Open Access Journals (Sweden)

    Sophie-Anne Scherrer

    Full Text Available Vertebral wedging is associated with spinal deformity progression in adolescent idiopathic scoliosis. Reporting frontal and sagittal wedging separately could be misleading since these are projected values of a single three-dimensional deformation of the vertebral body. The objectives of this study were to determine if three-dimensional vertebral body wedging is present in mild scoliosis and if there are a preferential vertebral level, position and plane of deformation with increasing scoliotic severity.Twenty-seven adolescent idiopathic scoliotic girls with mild to moderate Cobb angles (10° to 50° participated in this study. All subjects had at least one set of bi-planar radiographs taken with the EOS® X-ray imaging system prior to any treatment. Subjects were divided into two groups, separating the mild (under 20° from the moderate (20° and over spinal scoliotic deformities. Wedging was calculated in three different geometric planes with respect to the smallest edge of the vertebral body.Factorial analyses of variance revealed a main effect for the scoliosis severity but no main effect of vertebral Levels (apex and each of the three vertebrae above and below it (F = 1.78, p = 0.101. Main effects of vertebral Positions (apex and above or below it (F = 4.20, p = 0.015 and wedging Planes (F = 34.36, p<0.001 were also noted. Post-hoc analysis demonstrated a greater wedging in the inferior group of vertebrae (3.6° than the superior group (2.9°, p = 0.019 and a significantly greater wedging (p≤0.03 along the sagittal plane (4.3°.Vertebral wedging was present in mild scoliosis and increased as the scoliosis progressed. The greater wedging of the inferior group of vertebrae could be important in estimating the most distal vertebral segment to be restrained by bracing or to be fused in surgery. Largest vertebral body wedging values obtained in the sagittal plane support the claim that scoliosis could be initiated

  1. A possible mechanism for earthquakes found in the mantle wedge of the Nazca subduction zone

    Science.gov (United States)

    Warren, L. M.; Chang, Y.; Prieto, G. A.

    2017-12-01

    Beneath Colombia, the Cauca cluster of intermediate-depth earthquakes extends for 200 km along the trench (3.5°N-5.5°N, 77.0°W-75.3°W) and, with 58 earthquakes per year with local magnitude ML >= 2.5, has a higher rate of seismicity than the subduction zone immediately to the north or south. By precisely locating 433 cluster earthquakes from 1/2010-3/2014 with data from the Colombian National Seismic Network, we found that the earthquakes are located both in a continuous Nazca plate subducting at an angle of 33°-43° and in the overlying mantle wedge. The mantle wedge earthquakes (12% of the earthquakes) form two isolated 40-km-tall columns extending perpendicular to the subducting slab. Using waveform inversion, we computed focal mechanisms for 69 of the larger earthquakes. The focal mechanisms are variable, but the intraslab earthquakes are generally consistent with an in-slab extensional stress axis oriented 25° counterclockwise from the down-dip direction. We suggest that the observed mantle wedge earthquakes are the result of hydrofracture in a relatively cool mantle wedge. This segment of the Nazca Plate is currently subducting at a normal angle, but Wagner et al. (2017) suggested that a flat slab slowly developed in the region between 9-5.9 Ma and persisted until 4 Ma. During flat slab subduction, the overlying mantle wedge typically cools because it is cut off from mantle corner flow. After hydrous minerals in the slab dehydrate, the dehydrated fluid is expelled from the slab and migrates through the mantle wedge. If a cool mantle wedge remains today, fluid dehydrated from the slab may generate earthquakes by hydrofracture, with the mantle wedge earthquakes representing fluid migration pathways. Dahm's (2000) model of water-filled fracture propagation in the mantle wedge shows hydrofractures propagating normal to the subducting slab and extending tens of km into the mantle wedge, as we observe.

  2. Case report: multifocal subchondral stress fractures of the femoral heads and tibial condyles in a young military recruit.

    Science.gov (United States)

    Yoon, Pil Whan; Yoo, Jeong Joon; Yoon, Kang Sup; Kim, Hee Joong

    2012-03-01

    Subchondral stress fractures of the femoral head may be either of the insufficiency-type with poor quality bone or the fatigue-type with normal quality bone but subject to high repetitive stresses. Unlike osteonecrosis, multiple site involvement rarely has been reported for subchondral stress fractures. We describe a case of multifocal subchondral stress fractures involving femoral heads and medial tibial condyles bilaterally within 2 weeks. A 27-year-old military recruit began having left knee pain after 2 weeks of basic training, without any injury. Subsequently, right knee, right hip, and left hip pain developed sequentially within 2 weeks. The diagnosis of multifocal subchondral stress fracture was confirmed by plain radiographs and MR images. Nonoperative treatment of the subchondral stress fractures of both medial tibial condyles and the left uncollapsed femoral head resulted in resolution of symptoms. The collapsed right femoral head was treated with a fibular strut allograft to restore congruity and healed without further collapse. There has been one case report in which an insufficiency-type subchondral stress fracture of the femoral head and medial femoral condyle occurred within a 2-year interval. Because the incidence of bilateral subchondral stress fractures of the femoral head is low and multifocal involvement has not been reported, multifocal subchondral stress fractures can be confused with multifocal osteonecrosis. Our case shows that subchondral stress fractures can occur in multiple sites almost simultaneously.

  3. Unicompartmental knee prostheses: in vitro wear assessment of the menisci tibial insert after two different fixation methods

    International Nuclear Information System (INIS)

    Affatato, S; Spinelli, M; Zavalloni, M; Viceconti, M; Carmignato, S; Lopomo, N; Marcacci, M

    2008-01-01

    Knee osteoarthritis is a complex clinical scenario where many biological and mechanical factors influence the severity of articular degenerative changes. Minimally invasive knee prosthetic surgery, with only a compartment replacement (unicompartmental knee replacement), might be a good compromise between osteotomy and total knee prosthesis. The focus of this study was to develop and validate a protocol to assess the fixation method of the femoral components in mechanical simulation, for pre-clinical validation; the wear behaviour of two different fixation frames was quantified and compared. In particular, two different wear tests were conducted using the same knee simulator, the same load profiles and the same kinematics; two different fixation methods were applied to the femoral sleds (synthetic femur and metal block). Surface characterization on both articulating bearings was performed by a roughness measuring machine and coordinate measuring machine. The wear produced by the tibial inserts using the synthetic femur was considerably higher than the wear registered by the metal-block holder. Roughness measurements on femoral sleds showed a limited number of scratches with high R t values for the metal-block set-up; the damaged surface broadened in the case of femoral condyles and tibial inserts mounted on composite bone, but lower R t and linear penetration values were measured. The two holding frames showed different wear activities as a consequence of dissimilar dynamic performance. Further observations should be made in vivo to prove the actual importance of synthetic bone simulations and specific material behaviour

  4. Tibial Slope Strongly Influences Knee Stability After Posterior Cruciate Ligament Reconstruction: A Prospective 5- to 15-Year Follow-up.

    Science.gov (United States)

    Gwinner, Clemens; Weiler, Andreas; Roider, Manoussos; Schaefer, Frederik M; Jung, Tobias M

    2017-02-01

    The reported failure rate after posterior cruciate ligament (PCL) reconstruction remains high. Previous studies have shown that the tibial slope (TS) influences sagittal plane laxity. Consequently, alterations of TS might have an effect on postoperative knee stability after PCL reconstruction. We hypothesized that flattening of TS is associated with increased posterior laxity after PCL reconstruction. Cohort study; Level of evidence 3. This study consisted of 48 patients who underwent PCL reconstruction in a single-surgeon series. Eight patients underwent an isolated PCL reconstruction, 27 patients underwent an additional posterolateral corner reconstru