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.

Opening wedge trapezial osteotomy as possible treatment for early trapeziometacarpal osteoarthritis: a biomechanical investigation of radial subluxation, contact area, and contact pressure.

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Cheema, Tahseen; Salas, Christina; Morrell, Nathan; Lansing, Letitia; Reda Taha, Mahmoud M; Mercer, Deana

2012-04-01

Radial subluxation and cartilage thinning have been associated with initiation and accelerated development of osteoarthritis of the trapeziometacarpal joint. Few investigators have reported on the benefits of opening wedge trapezial osteotomy for altering the contact mechanics of the trapeziometacarpal joint as a possible deterrent to the initiation or progression of osteoarthritis. We used cadaveric specimens to determine whether opening wedge osteotomy of the trapezium was successful in reducing radial subluxation of the metacarpal base and to quantify the contact area and pressure on the trapezial surface during simulated lateral pinch. We used 8 fresh-frozen specimens in this study. The flexor pollicis longus, abductor pollicis longus, adductor pollicis, abductor pollicis brevis, and flexor pollicis brevis/opponens pollicis tendons were each loaded to simulate the thumb in lateral pinch position. We measured radial subluxation from anteroposterior radiographs before and after placement of a 15° wedge. We used real-time sensors to analyze contact pressure and contact area distribution on the trapezium. Center of force in the normal joint under lateral pinch loading was primarily located in the dorsal region of the trapezium. After wedge placement, contact pressure increased in the ulnar-dorsal region by 76%. Mean contact area increased in the ulnar-dorsal region from 0.05 to 0.07 cm(2), and in the ulnar-volar region from 0.003 to 0.024 cm(2). The average reduction in joint subluxation was 64%. The 15° opening wedge osteotomy of the trapezium reduced radial subluxation of the metacarpal on the trapezium and increased contact pressure and contact area away from the diseased compartments of the trapezial surface. Trapezial osteotomy addresses the 2 preeminent theories about the initiation and progression of osteoarthritis. By reducing radial subluxation and altering contact pressure and contact area, trapezial osteotomy may prove an alternative to first

[Open-wedge osteotomy of the glenoid for treatment of posterior shoulder instability with increased glenoid retroversion].

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Pogorzelski, J; Braun, S; Imhoff, A B; Beitzel, K

2016-12-01

Treatment of posterior shoulder instability with increased retroversion of the glenoid using open-wedge osteotomy of the glenoid neck stabilized with an autologous bone block. Symptomatic, atraumatic posterior shoulder instability with increased retroversion (>20°) of the glenoid and previously failed conservative or surgical treatment. General contraindications against surgery. Relative contraindications: osteoporosis, nicotine abuse, or suspected patient noncompliance. Posterior approach with a 7 cm long incision starting medial of the posterolateral corner of the acromion heading to the posterior axillary fold and subsequent preparation of the deltoid muscle and the infraspinatus muscle. The posterior glenohumeral capsule is incised by performing a capsular T‑shift. The osteotomy is performed intracapsulary medial to the genoid rim. The wedge bone graft, harvested from spina scapulae or iliac spine, is placed "press fit" in position. Additional fixation of the graft is not necessary if the anterior cortex is intact. For reinforcing the posterior capsule, a posterior capsule shift should be performed. Insertion of extracapsular wound drainage. Successive wound closure. Postoperative immobilization in a 0° shoulder orthesis for 6 weeks; avoidance of horizontal abduction for 8 weeks. After removing the wound drainage, start of limited active-assisted range of motion. Over-head sports after 6 months. From 2009-2015, 6 posterior open wedge glenoid osteotomies were performed. Postoperative retroversion of the glenoid was 11.2 ± 9.4° compared to 26.0 ± 8.6° before surgery. Of 6 shoulders, 2 showed postoperative signs of persistent posterior instability; the other 4 shoulders were free of complaints. No revision surgery was needed.

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...

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

Directory of Open Access Journals (Sweden)

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

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

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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.

First Metatarsophalangeal Contact Properties Following Proximal Opening Wedge and Scarf Osteotomies for Hallux Valgus Correction: A Biomechanical Study.

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Kia, Cameron; Yoshida, Ryu; Cote, Mark; DiVenere, Jessica; Geaney, Lauren E

2017-04-01

Proximal opening wedge osteotomy (POWO) is an established procedure for moderate to severe hallux valgus. A common concern of this procedure is that it results in lengthening of the first metatarsal, which could cause increased intra-articular pressure of the first metatarsophalangeal joint (MTP) and may ultimately lead to arthritis because of these altered mechanics. The purpose of this study was to use a cadaveric model to compare intra-articular pressures and articulating contact properties of the MTP joint following either scarf osteotomy or POWO. Fresh-frozen cadaveric below-knee specimens with pre-existing hallux valgus (n = 12) and specimens without hallux valgus (n = 6, control group) were used. The hallux valgus specimens were stratified into 2 groups (n = 6 each): POWO or scarf osteotomy. The groups were matched based on the degree of deformity. Peak intra-articular pressure, force, and area were measured in all normal, preoperative, and postoperative specimens with a simulated weightbearing model. These measurements were made with a pressure transducer placed within the first MTP joint. Postoperatively POWO group had slightly higher contact forces and pressures compared to the scarf group and lower contact forces and pressures than those of the normal group but were not statistically significant ( P > .05). Normal specimens had higher intra-articular force, pressure, and area than postoperative specimens but the difference was not found to be significant. First metatarsal lengthening was found in both the scarf and POWO specimens; however, neither increase was found to be significant ( P > .05). The results from this study show that after operative correction, contact properties of the fist MTP joint among normal, POWO, and scarf osteotomy groups revealed no significant differences. First MTP joints in those with hallux valgus had significantly lower contact force and pressure compared to those without hallux valgus. With little long-term outcomes of

Correction of moderate to severe hallux valgus with combined proximal opening wedge and distal chevron osteotomies: a reliable technique.

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Jeyaseelan, L; Chandrashekar, S; Mulligan, A; Bosman, H A; Watson, A J S

2016-09-01

The mainstay of surgical correction of hallux valgus is first metatarsal osteotomy, either proximally or distally. We present a technique of combining a distal chevron osteotomy with a proximal opening wedge osteotomy, for the correction of moderate to severe hallux valgus. We reviewed 45 patients (49 feet) who had undergone double osteotomy. Outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) and the Short Form (SF) -36 Health Survey scores. Radiological measurements were undertaken to assess the correction. The mean age of the patients was 60.8 years (44.2 to 75.3). The mean follow-up was 35.4 months (24 to 51). The mean AOFAS score improved from 54.7 to 92.3 (p hallux valgus and intermetatarsal angles were improved from 41.6(o) to 12.8(o) (p < 0.001) and from 22.1(o) to 7.1(o), respectively (p < 0.001). The mean distal metatarsal articular angle improved from 23(o) to 9.7(o). The mean sesamoid position, as described by Hardy and Clapham, improved from 6.8 to 3.5. The mean length of the first metatarsal was unchanged. The overall rate of complications was 4.1% (two patients). These results suggest that a double osteotomy of the first metatarsal is a reliable, safe technique which, when compared with other metatarsal osteotomies, provides strong angular correction and excellent outcomes with a low rate of complications. Cite this article: Bone Joint J 2016;98-B:1202-7. ©2016 The British Editorial Society of Bone & Joint Surgery.

Relative strength of tailor's bunion osteotomies and fixation techniques.

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Haddon, Todd B; LaPointe, Stephan J

2013-01-01

A paucity of data is available on the mechanical strength of fifth metatarsal osteotomies. The present study was designed to provide that information. Five osteotomies were mechanically tested to failure using a materials testing machine and compared with an intact fifth metatarsal using a hollow saw bone model with a sample size of 10 for each construct. The osteotomies tested were the distal reverse chevron fixated with a Kirschner wire, the long plantar reverse chevron osteotomy fixated with 2 screws, a mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, the mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, and an additional cerclage wire and a transverse closing wedge osteotomy fixated with a box wire technique. Analysis of variance was performed, resulting in a statistically significant difference among the data at p chevron was statistically the strongest construct at 130 N, followed by the long plantar osteotomy at 78 N. The chevron compared well with the control at 114 N, and they both fractured at the proximal model to fixture interface. The other osteotomies were statistically and significantly weaker than both the chevron and the long plantar constructs, with no statistically significant difference among them at 36, 39, and 48 N. In conclusion, the chevron osteotomy was superior in strength to the sagittal and transverse plane osteotomies and similar in strength and failure to the intact model. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Evaluation of Hallux Valgus Correction With Versus Without Akin Proximal Phalanx Osteotomy.

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Shibuya, Naohiro; Thorud, Jakob C; Martin, Lanster R; Plemmons, Britton S; Jupiter, Daniel C

2016-01-01

Although the efficacy of Akin proximal phalanx closing wedge osteotomy as a sole procedure for correction of hallux valgus deformity is questionable, when used in combination with other osseous corrective procedures, the procedure has been believed to be efficacious. However, a limited number of comparative studies have confirmed the value of this additional procedure. We identified patients who had undergone osseous hallux valgus correction with first metatarsal osteotomy or first tarsometatarsal joint arthrodesis with (n = 73) and without (n = 81) Akin osteotomy and evaluated their radiographic measurements at 3 points (preoperatively, within 3 months after surgery, and ≥6 months after surgery). We found that those people who had undergone the Akin procedure tended to have a larger hallux abduction angle and a more laterally deviated tibial sesamoid position preoperatively. Although the radiographic correction of the deformity was promising immediately after corrective surgery with the Akin osteotomy, maintenance of the correction was questionable in our cohort. The value of additional Akin osteotomy for correction of hallux valgus deformity is uncertain. Published by Elsevier Inc.

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

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

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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.

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.

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

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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

Ankle joint pressure changes in a pes cavovarus model: supramalleolar valgus osteotomy versus lateralizing calcaneal osteotomy.

Science.gov (United States)

Schmid, Timo; Zurbriggen, Sebastian; Zderic, Ivan; Gueorguiev, Boyko; Weber, Martin; Krause, Fabian G

2013-09-01

A fixed cavovarus foot deformity can be associated with anteromedial ankle arthrosis due to elevated medial joint contact stresses. Supramalleolar valgus osteotomies (SMOT) and lateralizing calcaneal osteotomies (LCOT) are commonly used to treat symptoms by redistributing joint contact forces. In a cavovarus model, the effects of SMOT and LCOT on the lateralization of the center of force (COF) and reduction of the peak pressure in the ankle joint were compared. A previously published cavovarus model with fixed hindfoot varus was simulated in 10 cadaver specimens. Closing wedge supramalleolar valgus osteotomies 3 cm above the ankle joint level (6 and 11 degrees) and lateral sliding calcaneal osteotomies (5 and 10 mm displacement) were analyzed at 300 N axial static load (half body weight). The COF migration and peak pressure decrease in the ankle were recorded using high-resolution TekScan pressure sensors. A significant lateral COF shift was observed for each osteotomy: 2.1 mm for the 6 degrees (P = .014) and 2.3 mm for the 11 degrees SMOT (P = .010). The 5 mm LCOT led to a lateral shift of 2.0 mm (P = .042) and the 10 mm LCOT to a shift of 3.0 mm (P = .006). Comparing the different osteotomies among themselves no significant differences were recorded. No significant anteroposterior COF shift was seen. A significant peak pressure reduction was recorded for each osteotomy: The SMOT led to a reduction of 29% (P = .033) for the 6 degrees and 47% (P = .003) for the 11 degrees osteotomy, and the LCOT to a reduction of 41% (P = .003) for the 5 mm and 49% (P = .002) for the 10 mm osteotomy. Similar to the COF lateralization no significant differences between the osteotomies were seen. LCOT and SMOT significantly reduced anteromedial ankle joint contact stresses in this cavovarus model. The unloading effects of both osteotomies were equivalent. More correction did not lead to significantly more lateralization of the COF or more reduction of peak pressure but a trend was

Correction of Hallux Valgus Interphalangeus With an Osteotomy of the Distal End of the Proximal Phalanx (Distal Akin Osteotomy).

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Vander Griend, Robert

2017-02-01

Operative correction of a symptomatic hallux valgus interphalangeus (HVI) deformity is often achieved with an osteotomy at the proximal end of the proximal phalanx (Akin osteotomy). However, the apex of the typical HVI deformity (center of rotation angle) is at the interphalangeal joint of the hallux. This study was done to evaluate the results of performing a medial closing wedge osteotomy at the distal end of the proximal phalanx. Thirty-three patients (33 feet) underwent an osteotomy at the distal end of the proximal phalanx for correction of HVI. All of the patients had other forefoot deformities which were corrected at the same time. Eight of these were revision procedures of prior forefoot operations. The length of follow-up was determined by the associated procedures with a minimum follow-up of 4 months. The preoperative hallux valgus interphalangeus angle averaged 16 degrees of valgus (range 7-32 degrees) and was corrected to an average of 2 degrees of valgus (range 5 degrees valgus to 5 degrees varus). All of the patients were satisfied with the postoperative appearance and function of the first toe. Because of simultaneous correction of numerous other forefoot problems, it was not possible to specifically isolate or evaluate the effects and benefits of this osteotomy using outcomes measures. There was one intraoperative complication resulting in a fracture extending into the adjacent IP joint. Correction of an HVI deformity can be achieved with an osteotomy at the distal end of the proximal phalanx. This was a safe technique with few complications and with good results in terms of both correction and patient satisfaction. Level IV, retrospective case series.

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

Science.gov (United States)

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.

[The minimally invasive Chevron and Akin osteotomy (MICA)].

Science.gov (United States)

Altenberger, Sebastian; Kriegelstein, Stefanie; Gottschalk, Oliver; Dreyer, Florian; Mehlhorn, Alexander; Röser, Anke; Walther, Markus

2018-04-18

Percutaneous correction of a hallux valgus deformity with or without transfer metatarsalgia. Hallux valgus deformity up to 20° intermetatarsal angle, without instability of the first tarsometatarsal joint. Symptomatic arthritis of the first metatarsophalangeal joint, as well as instability of the first tarsometatarsal joint. Percutaneous performed osteotomy of the distal metatarsal 1 in combination with a medial closing wedge osteotomy of the proximal phalanx of the first toe. The use of a postoperative shoe with a rigid sole allows adapted weight bearing in the first 6 weeks. Active and passive mobilization can start immediately after surgery. The method is very effective to treat even severe deformities with or without metatarsalgia. The amount of correction is similar to open procedures. We recommend cadaver training to become familiar with this technique. Thus, complications such as nerve, vessel or tendon injuries can be avoided. The intraoperative radiation exposure remains significantly elevated even for experienced surgeons. In addition to the aesthetic benefits, there is less soft tissue traumatization compared to conventional open procedures. There is no need of bloodlessness. The minimally invasive Chevron and Akin osteotomy is a safe and powerful technique for the treatment of hallux valgus deformity.

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.

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.

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.

Two-staged Bilateral, Femoral Alignment Osteotomy with Concomitant Total Knee Arthroplasty in an Achondroplasia Patient - A Case Report

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Walter, Sebastian G; Schwering, Tobias; Preiss, Stefan

2017-01-01

Introduction: Achondroplasia is the most common form of dwarfism in humans and is orthopedically characterized by shortened extremities and an exaggerated lumbar lordosis. The surgical challenges are maintenance of axial alignment during limb lengthening as well as joint preservation and alignment restoration. Case Report: We present a 46-year-old female suffering from achondroplasia with severe pain in both knees. Severe varus deformities of both femurs and degeneration of both knee joints became apparent on clinical and radiological examination. On each femur, we performed one-staged, lateral closed-wedge osteotomy, and total knee arthroplasty (TKA). Subsequently, the patient was relieved of knee joint pain and gained a greater range of motion. Conclusion: One-staged valgization osteotomy and concomitant TKA represents a challenging, yet reasonable, surgical solution in axially severe malaligned and joint degenerated patients. PMID:28819598

Patella height changes post high tibial osteotomy

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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.

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.

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.

Comparison of Puddu osteotomy with or without autologous bone grafting: a prospective clinical trial

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Marcus Ceregatti Passarelli

Full Text Available ABSTRACT Objectives: To test the hypothesis that autologous iliac bone grafts do not enhance clinical results and do not decrease complication rates in patients undergoing medial opening-wedge high tibial , osteotomy. Methods: Forty patients allocated in a randomized, two-armed, double-blinded clinical trial were evaluated between 2007 and 2010. One group received bone graft, and the other group was left without filling the osteotomy defect. The primary outcome was the Knee Society Score. , Radiographic measurement of the frontal anatomical femoral-tibial angle and the progression of osteoarthritis according to the modified Ahlback classification were used as secondary outcomes., Results: There was no difference in KSS scale between the graft group (64.4 ± 21.8 and the graftless group (61.6 ± 17.3; p= 0.309. There was no difference of angle between the femur and tibia in the frontal plane between the groups (graft, = 184 ± 4.6 degrees, graftless = 183.4 ± 5.1 degrees; p= 1.0, indicating that there is no loss of correction due to the lack of the graft. There was significant aggravation of osteoarthritis in a greater number of patients in a graft group (p= 0.005 . Conclusion: Autologous iliac bone graft does not improve clinical outcomes in medium and long-term follow-up of medial opening-wedge high tibial osteotomy fixed with a first generation Puddu plate in the conditions of this study.

Changes in ankle joint motion after Supramalleolar osteotomy: a cadaveric model.

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Kim, Hak Jun; Yeo, Eui Dong; Rhyu, Im Joo; Lee, Soon-Hyuck; Lee, Yeon Soo; Lee, Young Koo

2017-09-09

Malalignment of the ankle joint has been found after trauma, by neurological disorders, genetic predisposition and other unidentified factors, and results in asymmetrical joint loading. For a medial open wedge supramalleolar osteotomy(SMO), there are some debates as to whether concurrent fibular osteotomy should be performed. We assessed the changes in motion of ankle joint and plantar pressure after supramalleolar osteotomy without fibular osteotomy. Ten lower leg specimens below the knee were prepared from fresh-frozen human cadavers. They were harvested from five males (10 ankles)whose average age was 70 years. We assessed the motion of ankle joint as well as plantar pressure for SS(supra-syndesmotic) SMO and IS(intra-syndesmotic) SMO. After the osteotomy, each specimen was subjected to axial compression from 20 N preload to 350 N representing half-body weight. For the measurement of the motion of ankle joint, the changes in gap and point, angles in ankle joint were measured. The plantar pressure were also recorded using TekScan sensors. The changes in the various gap, point, and angles movements on SS-SMO and IS-SMO showed no statistically significant differences between the two groups. Regarding the shift of plantar center of force (COF) were noted in the anterolateral direction, but not statistically significant. SS-SMO and IS-SMO with intact fibula showed similar biomechanical effect on the ankle joint. We propose that IS-SMO should be considered carefully for the treatment of osteoarthrosis when fibular osteotomy is not performed because lateral cortex fracture was less likely using the intrasyndesmosis plane because of soft tissue support.

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.

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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.

Two surgical approaches to fracture malunion repair.

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Rahal, Sheila C; Teixeira, Carlos R; Pereira-Júnior, Oduvaldo C M; Vulcano, Luiz C; Aguiar, Antonio J A; Rassy, Fabrício B

2008-12-01

Two birds were presented with malunion fractures. The first was a young toco toucan (Ramphastos toco) with malunion of the tarsometatarsus that was treated by an opening-wedge corrective osteotomy and an acrylic-pin external skeletal fixator (type II) to stabilize the osteotomy. The second bird was an adult southern caracara (Caracara plancus) with radial and ulnar malunion that was treated by closing-wedge osteotomies. Stabilization of the osteotomy sites was accomplished through a bone plate fixed cranially on the ulna with 6 cortical screws and an interfragmentary single wire in radius. In both cases, the malunion was corrected, but the manus of the southern caracara was amputated because of carpal joint luxation that induced malposition of the feathers.

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

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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.

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.

Clinical Comparison of Sinus Lift via Summers Osteotomy and Piezosurgery

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Mehrdad Radvar

2017-12-01

Full Text Available Introduction: Sinus lift is a process that could be performed by two methods. In the closed sinus lift, hybrid materials enter a suitable position through a created cavity. Afterwards, the materials are pressed without damaging the sinus membrane, and the implants are usually placed at the same time. Closed sinus lift is carried out via osteotomy and piezosurgery, and each of the techniques has certain advantages and limitations. The present study aimed to compare the clinical results of closed sinus lift using the summers osteotomy and piezosurgery. Materials and Methods: In this study, 20 patients requiring dental implants in the posterior segment of the maxilla via sinus lift surgery were randomly divided into two groups. The first group received piezosurgery, and the second group underwent summers osteotomy for sinus lift. Postoperative Schneiderian membrane perforation, inflammation, pain, bone gain, and bone loss were compared between the groups six months after the surgery using Mann-Whitney U test and two-sample t-test. Results: In the groups receiving piezosurgery and summers osteotomy, mean sinus lift was 3.6±0.9 and 4.0±2.2 mm, pain score was 1.1±1.2 and 0.9±0.8, bone gain was 2.2±0.8 and 3.1±1.3 mm, and crestal bone loss was 1.1±1.2 and 0.9±0.8 mm, respectively. Moreover, no Schneiderian membrane perforation was observed in the two methods, and the differences between the groups were not considered significant (P>0.05. Conclusion: According to the results, the clinical outcomes of piezosurgery in sinus lift are similar to those of summers osteotomy. Therefore, piezosurgery could be a proper alternative to summers osteotomy in sinus lift surgery.

Metatarsal Osteotomies: Complications.

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Reddy, Veerabhadra Babu

2018-03-01

Metatarsal osteotomies can be divided into proximal and distal. The proximal osteotomies, such as the oblique, segmental, set cut, and Barouk-Rippstein-Toullec (BRT) osteotomy, all provide the ability to significantly change the position of the metatarsal head without violating the joint. These osteotomies, however, have a high rate of nonunion when done without internal fixation and can lead to transfer metatarsalgia when done without regard to the parabola of metatarsal head position. Distal osteotomies such as the Weil and Helal offer superior healing but have an increased incidence of recurrent metatarsalgia, joint stiffness, and floating toe. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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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.

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

NARCIS (Netherlands)

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

Rotational Osteotomy for Hallux Valgus. A New Technique for Primary and Revision Cases

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Ortiz, Cristian; Wagner, Emilio

2017-01-01

More than 200 different surgical techniques exist for hallux valgus (HV). Some of them are designed for mild, moderate, or severe deformities depending on their correction power. Nevertheless, they all correct only the coronal and/or sagittal plane deformity. Just a handful of them correct the known axial malrotation that exists in most HV cases. This malrotation is one possible factor that could be the source of recurrence of an operated HV as it has been described. We describe a new technique which simultaneously corrects the metatarsal internal rotation and varus deformity by rotating the metatarsal through an oblique plane osteotomy. This is performed with no bone wedge resection. Also, there is a broader bone surface contact than on a transverse proximal osteotomy. This technique is easy to remember and relatively simple to perform in primary and revision cases. The authors results show that it is as safe and effective as other procedures, with some advantages to be discussed. Levels of Evidence: Diagnostic Level 5. See Instructions for Authors for a complete description of levels of evidence. PMID:28286430

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

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

Are Pericentric Inversions Reorganizing Wedge Shell Genomes?

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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.

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

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

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

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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.

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.

Sports activities after lower limb osteotomy.

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Gougoulias, Nikolaos; Khanna, Anil; Maffulli, Nicola

2009-01-01

Active sports participation can be important in some patients with degenerative joint disease in the lower limb. We investigated whether this is possible after an osteotomy for osteoarthritis of the hip, knee and ankle joints. We performed a literature search using Medline, Cochrane, CINAHL and Google Scholar with no restriction to time period or language using the keywords: 'osteotomy and sports'. Eleven studies (all level IV evidence) satisfied our inclusion and exclusion criteria. Nine reported on high tibial osteotomies, one on periacetabular osteotomies and one on distal tibial osteotomies. The Coleman Methodology Score to assess the quality of studies showed much heterogeneity in terms of study design, patient characteristics, management methods and outcome assessment. Participation in recreational sports is possible in most patients who were active in sports before lower limb osteotomy. In no study were patients able to participate in competitive sports. Intensive participation in sports after osteotomy may adversely affect outcome and lead to failures requiring re-operation. Patients may be able to remain active in selected sports activities after a lower limb osteotomy for osteoarthritis. More rapid progression of arthritis is however a possibility. Prospective comparative studies investigating activities and sports participation in age-matched patients undergoing osteotomy or joint replacement could lead to useful conclusions. Increased activity and active sports participation may lead to progression of arthritis and earlier failure requiring additional surgery.

Osteotomy of the knee

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... joint. A tibial osteotomy may make you look "knock-kneed." A femoral osteotomy may make you look " ... Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic ...

Posterior column reconstruction improves fusion rates at the level of osteotomy in three-column posterior-based osteotomies.

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Lewis, Stephen J; Mohanty, Chandan; Gazendam, Aaron M; Kato, So; Keshen, Sam G; Lewis, Noah D; Magana, Sofia P; Perlmutter, David; Cape, Jennifer

2018-03-01

To determine the incidence of pseudarthrosis at the osteotomy site after three-column spinal osteotomies (3-COs) with posterior column reconstruction. 82 consecutive adult 3-COs (66 patients) with a minimum of 2-year follow-up were retrospectively reviewed. All cases underwent posterior 3-COs with two-rod constructs. The inferior facets of the proximal level were reduced to the superior facets of the distal level. If that was not possible, a structural piece of bone graft either from the local resection or a local rib was slotted in the posterior column defect to re-establish continual structural posterior bone across the lateral margins of the resection. No interbody cages were used at the level of the osteotomy. There were 34 thoracic osteotomies, 47 lumbar osteotomies and one sacral osteotomy with a mean follow-up of 52 (24-126) months. All cases underwent posterior column reconstructions described above and the addition of interbody support or additional posterior rods was not performed for fusion at the osteotomy level. Among them, 29 patients underwent one or more revision surgeries. There were three definite cases of pseudarthrosis at the osteotomy site (4%). Six revisions were also performed for pseudarthrosis at other levels. Restoration of the structural integrity of the posterior column in three-column posterior-based osteotomies was associated with > 95% fusion rate at the level of the osteotomy. Pseudarthrosis at other levels was the second most common reason for revision following adjacent segment disease in the long-term follow-up.

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.

Short Lingual Osteotomy Using a Piezosurgery Ultrasonic Bone-Cutting Device During Sagittal Split Ramus Osteotomy.

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Kawase-Koga, Yoko; Mori, Yoshiyuki; Kanno, Yuki; Hoshi, Kazuto; Takato, Tsuyoshi

2015-10-01

Short lingual osteotomy is a useful method for the performance of sagittal split ramus osteotomy involving interference between the proximal and distal bone fragments when lateral differences exist in the setback distance. However, this procedure occasionally results in abnormal fracture and nerve injury; expert surgical skill is thus required. We herein describe a novel technique involving the use of an ultrasonic bone-cutting device (Piezosurgery; Mectron Medical Technology, Carasco, Italy) for vertical osteotomy posterior to the mandibular foramen. Successful short lingual osteotomy was performed using this technique with avoidance of abnormal fracture and neurovascular bundle damage.

Fernandez osteotomy of radio distal with mal united fracture

International Nuclear Information System (INIS)

Garcia Herrera, Alvaro; Bocanegra, Sergio; Suarez, Fabio

2003-01-01

We review prospectively our experience in the military hospital in Bogota, Colombia, with the opening-wedge osteotomy for the treatment of a mal united fracture of the distal end of the radius in fifty-six consecutive patients from 1990 to 2002. The indications for operation were pain predominantly in the radio-ulnar joint and functional limitation with grip strength loss. Preoperative radiographs revealed an average ulnar inclination of 14 degrees, an average ulnar variance of four millimeters, and increased dorsal tilt (colles deformity) that averaged 28 degrees. All patients had limited function. The average grip strength was a force of fifteen kilograms compared with a force of thirty-one kilograms in the contralateral hand. Postoperatively, all of the patients had substantial improvement in function, relief of pain and grip strength increased. The functional results were rated as very good in eleven patients, good in thirty-six, fair in nine

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

[Application of computer-aided osteotomy template design in treatment of developmental dysplasia of the hip with steel osteotomy].

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Tong, Kuang; Zhang, Yuanzhi; Zhang, Sheng; Yu, Bin

2013-06-01

To provide an accurate method for osteotomy in the treatment of developmental dysplasia of the hip with steel osteotomy by three-dimensional reconstruction and Reverse Engineering technique. Between January 2011 and December 2012, 13 children with developmental dysplasia of the hip underwent steel osteotomy. 3D CT scan pelvic images were obtained and transferred via a DICOM network into a computer workstation to construct 3D models of the hip using Materialise Mimics 14.1 software in STL format. These models were imported into Imageware 12.0 software for steel osteotomy simulation until a stable hip was attained in the anatomical position for dislocation or subluxation of the hip in older children. The osteotomy navigational templates were designed according to the anatomical features after a stable hip was reconstructed. These navigational templates were manufactured using a rapid prototyping technique. The reconstruction hips in these children show good matching property and acetabulum cover. The computer-aided design of osteotomy template provides personalized and accurate solutions in the treatment of developmental dysplasia of the hip with steel osteotomy in older children.

Is McMurray′s osteotomy obsolete?

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Phaltankar P

1995-10-01

Full Text Available A review of the method of performing, advantages, disadvantages of McMurray′s displacement osteotomy with regard to treatment of nonunion of transcervical fracture neck femur with viable femoral head was carried out in this study of ten cases, in view of the abandonment of the procedure in favour of angulation osteotomy. Good results obtained in the series attest to the usefulness of McMurray′s osteotomy in the difficult problem of nonunion of transcervical fracture neck femur in well selected cases with certain advantages over the angulation osteotomy due to the ′Armchair effect′.

Dimensions of Velopharyngeal Space following Maxillary Advancement with Le Fort I Osteotomy Compared to Zisser Segmental Osteotomy: A Cephalometric Study

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Furkan Erol Karabekmez

2015-01-01

Full Text Available The objectives of this study are to assess the velopharyngeal dimensions using cephalometric variables of the nasopharynx and oropharynx as well as to compare the Le Fort I osteotomy technique to Zisser’s anterior maxillary osteotomy technique based on patients’ outcomes within early and late postoperative follow-ups. 15 patients with severe maxillary deficiency treated with Le Fort I osteotomy and maxillary segmental osteotomy were assessed. Preoperative, early postoperative, and late postoperative follow-up lateral cephalograms, patient histories, and operative reports are reviewed with a focus on defined cephalometric landmarks for assessing velopharyngeal space dimension and maxillary movement (measured for three different tracing points. A significant change was found between preoperative and postoperative lateral cephalometric measurements regarding the distance between the posterior nasal spine and the posterior pharyngeal wall in Le Fort I osteotomy cases. However, no significant difference was found between preoperative and postoperative measurements in maxillary segmental osteotomy cases regarding the same measurements. The velopharyngeal area calculated for the Le Fort I osteotomy group showed a significant difference between the preoperative and postoperative measurements. Le Fort I osteotomy for advancement of upper jaw increases velopharyngeal space. On the other hand, Zisser’s anterior maxillary segmental osteotomy does not alter the dimension of the velopharyngeal space significantly.

New Technique: A Novel Femoral Derotation Osteotomy for Malrotation following Intramedullary Nailing

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S. Jagernauth

2012-01-01

Full Text Available A 19-year-old female patient sustained a closed spiral midshaft femoral fracture and subsequently underwent femoral intramedullary nail insertion. At followup she complained of difficulty in walking and was found to have a unilateral in-toeing gait. CT imaging revealed 30 degrees of internal rotation at the fracture site, which had healed. A circumferential osteotomy was performed distal to the united fracture site using a Gigli saw with the intramedullary femoral nail in situ. The static distal interlocking screws were removed and the malrotation was corrected. Two further static distal interlocking screws were inserted to secure the intramedullary nail in position. The osteotomy went on to union and her symptoms of pain, walking difficulty, and in-toeing resolved. Our paper is the first to describe a technique for derotation osteotomy following intramedullary malreduction that leaves the intramedullary nail in situ.

Segmental osteotomies of the maxilla.

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Rosen, H M

1989-10-01

Multiple segment Le Fort I osteotomies provide the maxillofacial surgeon with the capabilities to treat complex dentofacial deformities existing in all three planes of space. Sagittal, vertical, and transverse maxillomandibular discrepancies as well as three-dimensional abnormalities within the maxillary arch can be corrected simultaneously. Accordingly, optimal aesthetic enhancement of the facial skeleton and a functional, healthy occlusion can be realized. What may be perceived as elaborate treatment plans are in reality conservative in terms of osseous stability and treatment time required. The close cooperation of an orthodontist well-versed in segmental orthodontics and orthognathic surgery is critical to the success of such surgery. With close attention to surgical detail, the complication rate inherent in such surgery can be minimized and the treatment goals achieved in a timely and predictable fashion.

Radial wedge flange clamp

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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.

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

Z-osteotomy in hallux valgus: clinical and radiological outcome after Scarf osteotomy

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Marcus Jaeger

2009-05-01

Full Text Available Correction osteotomies of the first metatarsal are common surgical approaches in treating hallux valgus deformities whereas the Scarf osteotomy has gained popularity. The purpose of this study was to analyze short- and mid-term results in hallux valgus patients who underwent a Scarf osteotomy. The subjective and radiological outcome of 131 Scarf osteotomies (106 hallux valgus patients, mean age: 57.5 years, range: 22-90 years were retrospectively analyzed. Mean follow-up was 22.4 months (range: 6 months-5 years. Surgical indications were: intermetatarsal angle (IMA of 12-23°; increased proximal articular angle (PAA>8°, and range of motion of the metatarsophalangeal joint in flexion and extension >40°. Exclusion criteria were severe osteoporosis and/or osteoarthritis. The mean subjective range of motion (ROM of the great toe post-surgery was 0.8±1.73 points (0: full ROM, 10: total stiffness. The mean subjective cosmetic result was 2.7±2.7 points (0: excellent, 10: poor. The overall post-operative patient satisfaction with the result was high (2.1±2.5 points (0: excellent, 10: poor. The mean hallux valgus angle improvement was 16.6° (pre-operative mean value: 37.5° which was statistically significant (p<0.01. The IMA improved by an average of 5.96° from a pre-operative mean value of 15.4° (p<0.01. Neither osteonecrosis of the distal fragment nor peri-operative fractures were noted during the follow-up. In keeping with our follow-up results, the Scarf osteotomy approach shows potential in the therapy of hallux valgus. 筻

Biomechanical analysis of the effect of occlusal force on osteosynthesis following sagittal split ramus osteotomy

International Nuclear Information System (INIS)

Okuda, Katsuya; Nakajima, Masahiro; Kakudo, Kenji

2009-01-01

Relapse is sometimes observed during the postoperative course following sagittal split ramus osteotomy which is widely used to correct jaw deformities. Relapse may be caused by biomechanical factors such as the postoperative occlusal force. We evaluated serial changes in the stress distribution associated with postoperative occlusal force and jaw-closing pressure on the mandible and osteosynthesis plate using three-dimensional finite element analysis. Based on CT data, we produced mandibular models 1, 3, 6, and 12 months after sagittal split ramus osteotomy, and subjected them to simulated occlusal force and jaw-closing pressure. Changes in equivalent stress in the proximal and distal segments, at the osteosynthesis site, and the fixation plate were evaluated by three-dimensional finite element analysis. The equivalent stresses in the proximal and distal segments slightly increased over time from 1 to 12 months after the operation. In particular, marked stress concentration was observed at the anterior border of the ramus at each measurement area. Stress at the osteosynthesis site increased from 1 to 6 months after the operation, but decreased after 12 months. As a result of postoperative occlusal forces and jaw-closing pressure, stress was concentrated at the anterior border of the ramus in the proximal segment. Between 3 and 6 months after the operation, tensile stress was concentrated at the upper and lower ends of the osteotomy line at the osteosynthesis site. These biomechanical findings indicate the application of clockwise stress on the distal segment up to 6 months after the operation. We concluded that sagittal split ramus osteotomy runs the risk of relapse between 3 and 6 months after the operation. (author)

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

Tibial rotational osteotomy for idiopathic torsion. A comparison of the proximal and distal osteotomy levels.

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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.

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

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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.

Triple pelvic osteotomy in the treatment of hip dysplasia

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Vukašinović Zoran

2009-01-01

Full Text Available Introduction. Insufficient femoral head coverage is found in a variety of diseases, with acetabular dysplasia as the most frequent disorder and triple pelvic osteotomy as the most recently introduced surgical treatment. Objective. This study analyses pre- and postoperative pathoanatomic characteristics of triple in comparison to Salter and Chiari osteotomies, with a logistic regression analysis of outcome predictor and effect explanator factors in relation to the chosen type of operation. Methods. The study involved 136 adolescents treated with Salter and Chiari osteotomies or a triple pelvic osteotomy at the Institute of Orthopaedic Surgery 'Banjica' in Belgrade. The patients were between 10-20 years old at the time of operation. We collected and analyzed data from all the patients: illness history, operative parameters, preoperative and postoperative pathoanatomic data. The data was statistically processed using the statistical software SPSS, defining standard descriptive values, and by using the appropriate tests of analytic statistics: t-test for dependent and independent variables, χ2-test, Fisher's exact test, Wilcoxon's test, parameter correlation, one-way ANOVA, multi-factorial ANOVA and logistic regression, according to the type of the analyzed data and the conditions under which the statistical methods were applied. Results. The average CE angle after triple pelvic osteotomy was 43.5°, more improved than after the Salter osteotomy (33.0° and Chiari osteotomy (31.4° (F=16.822; p<0.01. Postoperative spherical congruence was also more frequent after the triple osteotomy than after the other two types of operations, and with a high significance. Preoperative painful discomfort was found to be a valid predictor of indications for the triple osteotomy over both Chiari and Salter osteotomies. The valid explanators of effect for the triple osteotomy are: postoperative joint congruence (compared to the Chiari osteotomy and increase in joint

Assessment of trochanteric osteotomy fragment union after acetabular fracture surgery.

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Dubina, Andrew G; Wickramaratne, Niluka; O'Toole, Robert V; Manson, Theodore T

2017-02-01

Trochanteric osteotomies are performed in conjunction with standard approaches to improve surgical exposure during open reduction and internal fixation (ORIF) of acetabular fractures. The literature on total hip arthroplasty reports nonunion rates as high as 30% associated with trochanteric osteotomies; however, few data exist regarding the outcomes of trochanteric osteotomies for acetabular fracture surgery. Our hypotheses were 1) patients receiving trochanteric osteotomies during ORIF of acetabular fractures have a low rate of nonunion of the osteotomy fragment, and 2) hip abduction precautions are not necessary with digastric type osteotomies. A retrospective review was conducted to identify patients with acetabular fractures between July 2002 and June 2010 (n=734 fractures) who required trochanteric osteotomies (n=64, 9% of fractures). Forty-seven met inclusion criteria of adequate follow-up (>56days). No excluded patient experienced a complication. Fractures were classified using the Letournel-Judet classification system. Only seven (20%) of 35 patients who received digastric osteotomies had hip abduction precautions applied during the postoperative period. All study patients were shown to have radiographic union at the trochanteric osteotomy site (100% union rate, n=47). Hip abduction precautions intended to protect the osteotomy site and reduce the risk of nonunion and fixation failure were infrequently applied to patients with digastric osteotomies (20%) in this cohort. Multiple protective factors against nonunion were present in this study population compared with previous arthroplasty studies from other institutions. Trochanteric osteotomies are not associated with a significant nonunion rate, and digastric osteotomies might be safely managed without hip abduction precautions. Copyright © 2016. Published by Elsevier Ltd.

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

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Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul

2013-01-01

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided. PMID:24340276

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

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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.

Modified Mitchell osteotomy alone does not have higher rate of residual metatarsalgia than combined first and lesser metatarsal osteotomy

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Shu-Jung Chen

2015-04-01

Full Text Available Transfer metatarsalgia (TM is a common forefoot disorder secondary to hallux valgus (HV. Some authors suggest that a combined lesser metatarsal osteotomy while undergoing HV surgery improves metatarsalgia, whereas others concluded that isolated HV corrective osteotomy can improve symptomatic metatarsalgia. The main purpose of this retrospective study was to compare clinical outcomes in patients with and without combined lesser metatarsal osteotomy while receiving HV correction surgery. We retrospectively reviewed the patients who underwent osteotomy for HV correction between January 2000 and December 2010. All patients underwent HV correction with modified Mitchell osteotomy. Clinical evaluations including the American Orthopaedic Foot and Ankle Society score and residual metatarsalgia were assessed, and radiographic measurements were carried out. Sixty-five patients (83 feet meeting the selection criteria were enrolled. Thirty feet receiving a combined lesser metatarsal osteotomy were classified as the combined surgery (CS group, and the others were classified as the control (CN group (53 feet. The overall rate of persistent symptomatic metatarsalgia was 19.28% after operative treatment. There were six feet with residual metatarsalgia in the CS group, and 10 feet in the CN group. There was no significant difference in the rate of persistent symptoms between the two groups (p = 0.9. According to this result, modified Mitchell osteotomy alone did not have a higher rate of residual metatarsalgia than CS. We also found that the average recovery rate of TM was about 80.7% and those patients whose preoperative HV angle was > 30° had the higher risk of residual metatarsalgia after surgery.

Repair of femoral trochanteric osteotomy in the dog

International Nuclear Information System (INIS)

Whitelock, R.G.; Dyce, J.; Houlton, J.E.F.

1997-01-01

The records and radiographs of 24 dogs that underwent femoral trochanteric osteotomy repair were reviewed. Osteotomy repair was performed with either a pin and tension band wire or a lag screw technique. Significant clinical complications associated with the osteotomy were identified in one dog (4 per cent) six weeks after surgery, although abnormal radiographic changes were evident in 15 dogs (62 per cent). The method of repair did not influence healing and there were comparable radiographic complication rates. It is concluded that femoral trochanteric osteotomy is not associated with significant clinical problems, despite a high incidence of abnormal radiographic findings

External osteotomy in rhinoplasty: Piezosurgery vs osteotome.

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Tirelli, Giancarlo; Tofanelli, Margherita; Bullo, Federica; Bianchi, Max; Robiony, Massimo

2015-01-01

To achieve the desired outcome in rhinoplasty depends on many factors. Osteotomy and surgical reshaping of nasal bones are important steps that require careful planning and execution. The availability of different tools raises the question of which one provides significant advantages for both technique and surgical outcome. Our prospective randomized pilot study compared the outcome of post-traumatic rhinoplasty performed with two different external techniques: ultrasound osteotomic cut using the Piezosurgery Medical Device (Mectron, Carasco, Italy) and traditional external osteotomy. Forty-four lateral osteotomies of the nasal wall were performed in twenty-two patients. In twelve patients the osteotomies were conducted with a 2-mm traditional osteotome (control group), while in the remaining ten patients these were done with the Piezosurgery Medical Device (experimental group). At the postoperative evaluation, significantly lower pain, edema and ecchymosis were noticed in the experimental group (pPiezosurgery Medical Device allowed for safe lateral osteotomies in rhinoplasty preliminarily demonstrating the potential to reduce some of the most frequent complications of rhinoplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

Periacetabular osteotomy

DEFF Research Database (Denmark)

Klit, Jakob; Hartig-Andreasen, Charlotte; Jacobsen, Steffen

2013-01-01

Hip joint survivorship and functional outcome are traditional outcome measures applied after periacetabular osteotomy (PAO). Younger adults however have greater demands and expectations on the function of their hip joints and these demands are not expressed using traditional outcome assessment to...

PTT functional recovery in early stage II PTTD after tendon balancing and calcaneal lengthening osteotomy.

Science.gov (United States)

Brilhault, Jean; Noël, Vincent

2012-10-01

The decision to offer surgery for Stage II posterior tibial tendon deficiency (PTTD) is a difficult one since orthotic treatment has been documented to be a viable alternative to surgery at this stage. Taking this into consideration we limited our treatment to bony realignment by a lengthening calcaneus Evans osteotomy and tendon balancing. The goal of the study was to clinically evaluate PTT functional recovery with this procedure. The patient population included 17 feet in 13 patients. Inclusion was limited to early Stage II PTTD flatfeet with grossly intact but deficient PTT. Deficiency was assessed by the lack of hindfoot inversion during single heel rise test. The surgical procedure included an Evans calcaneal opening wedge osteotomy with triceps surae and peroneus brevis tendon lengthening. PTT function at follow up was evaluated by an independent examiner. Evaluation was performed at an average of 4 (range, 2 to 6.3) years. One case presented postoperative subtalar pain that required subtalar fusion. Every foot could perform a single heel rise with 13 feet having active inversion of the hindfoot during elevation. The results of this study provide evidence of PTT functional recovery without augmentation in early Stage II. It challenges our understanding of early Stage II PTTD as well as the surgical guidelines recommending PTT augmentation at this specific stage.

Segmental sandwich osteotomy and tunnel technique for three-dimensional reconstruction of the jaw atrophy: a case report.

Science.gov (United States)

Santagata, Mario; Sgaramella, Nicola; Ferrieri, Ivo; Corvo, Giovanni; Tartaro, Gianpaolo; D'Amato, Salvatore

2017-12-01

A three-dimensionally favourable mandibular bone crest is desirable to be able to successfully implant placement to meet the aesthetic and functional criteria in the implant-prosthetic rehabilitation. Several surgical procedures have been advocated for bone augmentation of the atrophic mandible, and the sandwich osteotomy is one of these techniques. The aim of the present case report was to assess the suitability of segmental mandibular sandwich osteotomy combined with a tunnel technique of soft tissue. Based on our knowledge, nobody described before the sandwich osteotomy with tunnel technique to improve the healing of the wound and meet the dimensional requirements of preimplant bone augmentation in cases of a severely atrophic mandible. A 59-year-old woman with a severely atrophied right mandible was treated with the sandwich osteotomy technique filled with autologous bone graft harvested by a cortical bone collector from the ramus. Clinical examination revealed that the mandible was edentulous bilaterally from the first molar to the second molar region. Radiographically, atrophy of the mandibular alveolar ridge in the same teeth site was observed. We began to treat the right side. A horizontal osteotomy of the edentulous mandibular bone was then made with a piezoelectric device after tunnel technique of the soft tissue. The segmental mandibular sandwich osteotomy (SMSO) was finished by two (mesial and distal) slightly divergent vertical osteotomies. The entire bone fragment was displaced cranially, and the desirable position was obtained. The gap was filled completely with autologous bone chips harvested from the mandibular ramus through a cortical bone collector. No barrier membranes were used to protect the grafts. The vertical incisions were closing with interruptive suturing of the flaps with a resorbable material. In this way, the suture will not fall on the osteotomy line of the jaw; the result will be a better predictability of soft and hard tissue

The effects of femoral external derotational osteotomy on frontal plane alignment.

Science.gov (United States)

Nelitz, M; Wehner, T; Steiner, M; Dürselen, L; Lippacher, S

2014-11-01

Femoral osteotomies are the preferred treatment in significant torsional deformity of the femur. The influence of torsional osteotomies on frontal plane alignment is poorly understood. Therefore, the aim of the present study was to evaluate the effects of external derotational osteotomies on proximal, mid-shaft and distal levels onto frontal plane alignment. The effect of rotation around the anatomical axis of the femur on frontal plane alignment was determined with a 3D computer model, created from CT data of a right human cadaver femur. Virtual torsional osteotomies of 10°, 20° and 30° were performed at proximal, mid-shaft and distal levels under five antecurvatum angles of the femur. The change of the frontal plane alignment was expressed by the mechanical lateral femoral angle. Proximal derotational osteotomies resulted in an increased mechanical lateral distal femoral angle (mLDFA) of 0.8°-2.6° for 10°, of 1.6°-5.1° for 20° and of 2.3-7.9° for 30° derotational osteotomy, indicating an increased varus angulation. Supracondylar derotational osteotomy resulted in a decreased mLDFA of -0.1° to -1.7° for 10°, of -0.2 to -3.7° for 20° and of -0.7 to -6.9° for 30° derotational osteotomy, indicating an increased valgus angulation. The effect increased with the amount of torsional correction and virtually increased antecurvatum angles. Mid-shaft torsional osteotomies had the smallest effect on frontal plane alignment. This three-dimensional computer model study demonstrates the relationship between femoral torsional osteotomies and frontal plane alignment. Proximal external derotational osteotomies tend to result in an increased varus angulation, whilst distal external derotational osteotomies tend to result in an increased valgus angulation. As a clinical consequence, torsional osteotomies have an increased risk of unintentional implications on frontal plane alignment.

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

A comparison of piezosurgery with conventional techniques for internal osteotomy.

Science.gov (United States)

Koçak, I; Doğan, R; Gökler, O

2017-06-01

To compare conventional osteotomy with the piezosurgery medical device, in terms of postoperative edema, ecchymosis, pain, operation time, and mucosal integrity, in rhinoplasty patients. In this prospective study, 49 rhinoplasty patients were randomly divided into two groups according to osteotomy technique used, either conventional osteotomy or piezosurgery. For all patients, the total duration of the operation was recorded, and photographs were taken and scored for ecchymosis and edema on postoperative days 2, 4, and 7. In addition, pain level was evaluated on postoperative day 2, and mucosal integrity was assessed on day 4. All scoring and evaluation was conducted by a physician who was blinded to the osteotomy procedure. In the piezosurgery group, edema scores on postoperative day 2 and ecchymosis scores on postoperative days 2, 4, and 7 were significantly lower than in the conventional osteotomy group (p piezosurgery group than in the conventional osteotomy group (p piezosurgery group. When total operation duration was compared, there was no significant difference between the groups (p > 0.05). Piezosurgery is a safe osteotomy method, with less edema (in the early postoperative period) and ecchymosis compared with conventional osteotomy, as well as less pain, a similar operation duration, and no mucosal damage.

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

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

the transfer matrix approach is shown to be consistent with scaling and thermodynamic requirements for distances close to and far from the wedge bottom respectively

A new technique for mandibular osteotomy

Directory of Open Access Journals (Sweden)

Puricelli Edela

2007-03-01

Full Text Available Abstract Sagittal split osteotomy (SSO is a surgical technique largely employed for mandibular mobilizations in orthognatic procedures. However, the traditional design of buccal osteotomy, located at the junction of mandibular ramus and body, may prevent more extensive sliding between the bone segments, particularly on the advance, laterality and verticality of the mandibular body. The author proposes a new technical and conceptual solution, in which osteotomy is performed in a more distal region, next to the mental formamen. Technically, the area of contact between medullary-cancellous bone surfaces is increased, resulting in larger sliding rates among bone segments; it also facilitates the use of rigid fixation systems, with miniplates and monocortical screws. Conceptually, it interferes with the resistance arm of the mandible, seen as an interpotent lever of the third gender.

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

A Novel Continuous Extrusion Process to Fabricate Wedge-Shaped Light Guide Plates

Directory of Open Access Journals (Sweden)

Wen-Tse Hsiao

2013-01-01

Full Text Available Backlight modules are key components in thin-film transistor liquid crystal displays (TFT-LCD. Among the components of a backlight module, the light guide plate (LGP plays the most important role controlling the light projected to the eyes of users. A wedge-shaped LGP, with its asymmetrical structure, is usually fabricated by an injection proces, but the fabrication time of this process is long. This study proposes a continuous extrusion process to fabricate wedge-shaped LGPs. This continuous process has advantages for mass production. Besides a T-die and rollers, this system also has an in situ monitor of the melt-bank that forms during the extrusion process, helping control the plate thickness. Results show that the melt bank has a close relationship with the plate thickness. The temperature of the bottom heater and roller was adjusted to reduce the surface deformation of the wedge-shaped plate. This continuous extrusion system can successfully manufacture wedge-shaped LGPs for mass production.

The Level of Fibula Osteotomy and Incidence of Peroneal Nerve ...

African Journals Online (AJOL)

2010-06-29

Jun 29, 2010 ... Journal of Surgical Technique and Case Report | Jan-Jun 2010 | Vol-2 | Issue-1. 17. The Level of Fibula Osteotomy and Incidence of Peroneal. Nerve Palsy in Proximal Tibial Osteotomy. A. O. Ogbemudia, P. F. A. Umebese, A. Bafor, E. Igbinovia, P. E. Ogbemudia. INTRODUCTION. Osteotomy of the fibula is ...

Distal Metatarsal Osteotomy in Hallux Valgus Surgery: Chevron Osteotomy

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Fatih Dogar

2016-04-01

Full Text Available Aim: Hallux valgus is a complex foot deformity resulting from medial deviation of first metatarsal and lateral deviation of toe. Radiographic and functional outcomes of chevron type distal metatarsal osteotomy applied to symptomatic hallux valgus patients with moderate deformity were assessed in the present study. Chevron osteotomy was applied to 27 feet (13 left, 14 right of 22 patients (12 women and 10 men; mean age: 45±16.7 years. Mean follow-up was 15.4± 4.71 months (range, 10%u201324. Material and Method: The average preoperative AOFAS score of 39.1 ± 8.55 (range, 32%u201357 improved (p < 0.0001 to 87.8 ± 4.7 (range, 82%u201397. The average preoperative hallux valgus angle (HVA of 37.4 ± 5.8 (range, 29%u201350 improved (p < 0.0001 to 14.8 ± 3.1 (range, 10%u201320 , and the average preoperative intermetatarsal 1-2 angle (IMA of 13.1 ± 1.5 (range, 11%u201317 improved (p < 0.0001 to 7.1 ± 1.4 (range, 5%u20139 . The average sesamoid position improved from 2.9 ± 0.2 (range, 2-3 preoperatively to 1.2 ± 0.4 (range, 1-2 (p < 0.0001. Toe hypoesthesia was developed in one patient as a complication. At the end of follow-up, patient satisfaction was found to be excellent in 16 feet (59.2% and good in 11 feet (40.8%. Results: The results of the study that chevron osteotomy yields good radiological result, high degree of postoperative patient satisfaction with minimal complications. Chevron ostoetomy is most effective method in the treatment of moderate hallux valgus.

The True Ponte Osteotomy: By the One Who Developed It.

Science.gov (United States)

Ponte, Alberto; Orlando, Giuseppe; Siccardi, Gian Luigi

2018-01-01

Technique and applications. To define the anatomy, biomechanics, indications, and surgical technique of the true Ponte osteotomy. The Ponte osteotomy, originally developed for thoracic kyphosis, was the first one to obtain posterior shortening of the thoracic spine, maintaining the anterior column load-sharing capacity. It has become a widely applied technique in various types of spine deformities and a frequent topic of presentations at meetings and in scientific articles. Several of them offer unquestionable evidence of an incorrect execution, with consequently distorted outcomes and erroneous conclusions. A clearing up became essential. Our original experience is based on a series of 240 patients with thoracic hyperkyphosis operated in the years 1969-2015, at first with a standard posterior Harrington technique and then by using the Ponte osteotomy with different instrumentations. A series of 78 of them, operated in the years 1987-1997, who had Ponte osteotomies at every level, is presented. The average preoperative kyphosis has been corrected from 80° (range 61°-102°) to 31° (range 15°-50°) by a substantial posterior shortening. A number of publications use the term Ponte osteotomy loosely for by far incomplete resections and mixing it up with Smith-Petersen's osteotomy. The true Ponte osteotomy is capable of producing marked flexibility in extension, flexion and rotation, justifying its wide use in thoracic deformities, mainly in scoliosis. An exact performance of the osteotomy with adequate bony resections, including the laminae, is an absolute condition to take full advantage of its properties. Level IV, therapeutic study. Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Cranial nerve injury after Le Fort I osteotomy.

Science.gov (United States)

Kim, J-W; Chin, B-R; Park, H-S; Lee, S-H; Kwon, T-G

2011-03-01

A Le Fort I osteotomy is widely used to correct dentofacial deformity because it is a safe and reliable surgical method. Although rare, various complications have been reported in relation to pterygomaxillary separation. Cranial nerve damage is one of the serious complications that can occur after Le Fort I osteotomy. In this report, a 19-year-old man with unilateral cleft lip and palate underwent surgery to correct maxillary hypoplasia, asymmetry and mandibular prognathism. After the Le Fort I maxillary osteotomy, the patient showed multiple cranial nerve damage; an impairment of outward movement of the eye (abducens nerve), decreased vision (optic nerve), and paraesthesia of the frontal and upper cheek area (ophthalmic and maxillary nerve). The damage to the cranial nerve was related to an unexpected sphenoid bone fracture and subsequent trauma in the cavernous sinus during the pterygomaxillary osteotomy. Copyright © 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Uniform physical theory of diffraction equivalent edge currents for truncated wedge strips

DEFF Research Database (Denmark)

Johansen, Peter Meincke

1996-01-01

New uniform closed-form expressions for physical theory of diffraction equivalent edge currents are derived for truncated incremental wedge strips. In contrast to previously reported expressions, the new expressions are well behaved for all directions of incidence and observation and take a finite...... value for zero strip length. This means that the expressions are well suited for implementation in general computer codes. The new expressions are expressed as the difference between two terms. The first term is obtained by integrating the exact fringe wave current on a wedge along an untruncated...

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.

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.

Dispersion analysis and measurement of circular cylindrical wedge-like acoustic waveguides.

Science.gov (United States)

Yu, Tai-Ho

2015-09-01

This study investigated the propagation of flexural waves along the outer edge of a circular cylindrical wedge, the phase velocities, and the corresponding mode displacements. Thus far, only approximate solutions have been derived because the corresponding boundary-value problems are complex. In this study, dispersion curves were determined using the bi-dimensional finite element method and derived through the separation of variables and the Hamilton principle. Modal displacement calculations clarified that the maximal deformations appeared at the outer edge of the wedge tip. Numerical examples indicated how distinct thin-film materials deposited on the outer surface of the circular cylindrical wedge influenced the dispersion curves. Additionally, dispersion curves were measured using a laser-induced guided wave, a knife-edge measurement scheme, and a two-dimensional fast Fourier transform method. Both the numerical and experimental results correlated closely, thus validating the numerical solution. Copyright © 2015 Elsevier B.V. All rights reserved.

Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

Science.gov (United States)

Deorio, J K; Ware, A W

2001-10-01

The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

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

Bamboo Osteotomy for Blount’s Disease

Directory of Open Access Journals (Sweden)

PU Siregar

2010-03-01

Full Text Available Blount disease is a common childhood condition that requires surgical correction. The conventional method of osteotomy and acute correction is associated with risk of neurovascular complications and occasionally displacement of the intra operative alignment. This case report describes a new technique that involves multiple longitudinal osteotomies over the proximal tibia without loss of cortical continuity between the proximal and distal tibia. It simulates an incomplete (greenstick fracture that allows plastic deformation at the site of correction. This correction is more stable, and can be expected to heal more rapidly than conventional treatments.

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

Computer assisted SCFE osteotomy planning

International Nuclear Information System (INIS)

Drapikowski, Pawel; Tyrakowski, Marcin; Czubak, Jaroslaw; Czwojdzinski, Adam

2008-01-01

Slipped capital femoral epiphysis (SCFE) is a common pediatric orthopedic disorder that requires surgical correction. Preoperative planning of a proximal femoral osteotomy is essential in cases of SCFE. This planning is usually done using 2D radiographs, but 3D data can be acquired with CT and analyzed with 3D visualization software. SCFEanalyzer is a computer program developed for preoperative planning of proximal femoral osteotomy to correct SCFE. Computed tomography scans were performed on human bone specimens: one pelvis and two femoral bones (right and left) and volume data of a patient. The CT data were used to test the abilities of the SCFEanalyzer software, which utilizes 3D virtual models of anatomic structures constructed from CT image data. Separation of anatomical bone structures is done by means of ''cutting'' 3D surface model of the pelvis. The software enables qualitative and quantitative spatial analysis of chosen parameters analogous to those done on the basis of plain radiographs. SCFEanalyzer makes it possible to evaluate the function of the hip joint by calculating the range of motion depending on the shape of bone structures based on oriented bounding box object representation. Pelvic and hip CT scans from a patient with SCFE were subjected to femoral geometry analysis and hip joint function assessment. These were done to plan and simulate osteotomy of the proximal femur. Analogous qualitative and quantitative evaluation after performing the virtual surgery were evaluated to determine the potential treatment effects. The use of computer assistance in preoperative planning enable us to increase objectivity and repeatability, and to compare the results of different types of osteotomy on the proximal femur, and thus to choose the optimal operation in each individual case. (orig.)

Computer assisted SCFE osteotomy planning

Energy Technology Data Exchange (ETDEWEB)

Drapikowski, Pawel [Poznan University of Technology, Institute of Control and Information Engineering, Poznan (Poland); Tyrakowski, Marcin; Czubak, Jaroslaw; Czwojdzinski, Adam [Postgraduate Medical Education Center, Department of Orthopaedics, Warsaw (Poland)

2008-11-15

Slipped capital femoral epiphysis (SCFE) is a common pediatric orthopedic disorder that requires surgical correction. Preoperative planning of a proximal femoral osteotomy is essential in cases of SCFE. This planning is usually done using 2D radiographs, but 3D data can be acquired with CT and analyzed with 3D visualization software. SCFEanalyzer is a computer program developed for preoperative planning of proximal femoral osteotomy to correct SCFE. Computed tomography scans were performed on human bone specimens: one pelvis and two femoral bones (right and left) and volume data of a patient. The CT data were used to test the abilities of the SCFEanalyzer software, which utilizes 3D virtual models of anatomic structures constructed from CT image data. Separation of anatomical bone structures is done by means of ''cutting'' 3D surface model of the pelvis. The software enables qualitative and quantitative spatial analysis of chosen parameters analogous to those done on the basis of plain radiographs. SCFEanalyzer makes it possible to evaluate the function of the hip joint by calculating the range of motion depending on the shape of bone structures based on oriented bounding box object representation. Pelvic and hip CT scans from a patient with SCFE were subjected to femoral geometry analysis and hip joint function assessment. These were done to plan and simulate osteotomy of the proximal femur. Analogous qualitative and quantitative evaluation after performing the virtual surgery were evaluated to determine the potential treatment effects. The use of computer assistance in preoperative planning enable us to increase objectivity and repeatability, and to compare the results of different types of osteotomy on the proximal femur, and thus to choose the optimal operation in each individual case. (orig.)

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)

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

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

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.

New modified technique of osteotomy for hallux valgus.

Science.gov (United States)

Oh, I S; Kim, M K; Lee, S H

2004-12-01

To improve the technique of osteotomy for hallux valgus (bunion). 38 cases of a new modified osteotomy procedure for hallux valgus were performed for 22 patients (21 women and one man). During a 3-year (range, 2-5 years) follow-up, the patients underwent physical examination; and their American Orthopedic Foot and Ankle Society hallux-metatarso-phalangeal-interphalangeal scale scores and standard foot radiographic measurements were recorded. 20 of the 22 patients (38 cases) had no pain, achieved good cosmesis, and were completely satisfied with the results of the operation. The remaining 2 patients had occasional mild discomfort. The mean hallux-metatarso-phalangeal-interphalangeal scale score was 93 points (range, 78-100 points). The mean preoperative and postoperative metatarsophalangeal angles were 34 degrees and 11 degrees, respectively. The mean postoperative reduction of the intermetatarsal angle and metatarsophalangeal angle were 6 degrees and 23 degrees, respectively. The new technique of osteotomy achieved even greater stability and accurate correction of the deformity in our 38 cases. Furthermore, it was more effective than conventional 'chevron' osteotomy in terms of correction of the deformity. Therefore, it should be used more widely.

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...

Biomechanical optimization of different fixation modes for a proximal femoral L-osteotomy

Directory of Open Access Journals (Sweden)

Chen Hsih-Hao

2009-09-01

Full Text Available Abstract Background Numerous proposed surgical techniques have had minimal success in managing greater trochanter overgrowth secondary to retarded growth of the femoral capital epiphysis. For reconstruction of residual hip deformities, a novel type of proximal femur L-osteotomy was performed with satisfactory results. Although the clinical outcome was good, the biomechanical characteristics of the femur after such an osteotomy have not been clearly elucidated. Therefore, this study presents a three dimensional finite element analysis designed to understand the mechanical characteristics of the femur after the L-osteotomy. Methods A patient with left hip dysplasia was recruited as the study model for L-osteotomy. The normal right hip was used as a reference for performing the corrective surgery. Four FEA models were constructed using different numbers of fixation screws but the same osteotomy lengths together with four FEA models with the same number of fixation screws but different osteotomy lengths. The von Mises stress distributions and femoral head displacements were analyzed and compared. Results The results revealed the following: 1. The fixation devices (plate and screws sustained most of the external loading, and the peak value of von Mises stress on the fixation screws decreased with an increasing number of screws. 2. Additional screws are more beneficial on the proximal segment than on the distal segment for improving the stability of the postoperative femur. 3. The extent of osteotomy should be limited because local stress might be concentrated in the femoral neck region with increasing length of the L-osteotomy. Conclusion Additional screw placement on the proximal segment improves stability in the postoperative femur. The cobra-type plate with additional screw holes in the proximal area might improve the effectiveness of L-osteotomies.

Impingement of water droplets on wedges and diamond airfoils at supersonic speeds

Science.gov (United States)

Serafini, John S

1953-01-01

An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees to 460 degrees R. Also, free-stream Mach numbers from 1.1 to 2.0, semi-apex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.

A guiding oblique osteotomy cut to prevent bad split in sagittal split ramus osteotomy: a technical note

Directory of Open Access Journals (Sweden)

Gururaj Arakeri

2015-06-01

Full Text Available Aim: To present a simple technical modification of a medial osteotomy cut which prevents its misdirection and overcomes various anatomical variations as well as technical problems. Methods: The medial osteotomy cut is modified in the posterior half at an angle of 15°-20° following novel landmarks. Results: The proposed cut exclusively directs the splitting forces downwards to create a favorable lingual fracture, preventing the possibility of an upwards split which would cause a coronoid or condylar fracture. Conclusion: This modification has proven to be successful to date without encountering the complications of a bad split or nerve damage.

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

Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

Energy Technology Data Exchange (ETDEWEB)

Eldiwany, B.; Alvarez, P.D. [Kalsi Engineering Inc., Sugar Land, TX (United States); Wolfe, K. [Electric Power Research Institute, Palo Alto, CA (United States)

1996-12-01

An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging and unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during {Delta}P closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data.

Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

International Nuclear Information System (INIS)

Eldiwany, B.; Alvarez, P.D.; Wolfe, K.

1996-01-01

An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging and unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during ΔP closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data

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.

Comparative Outcomes Between Step-Cut Lengthening Calcaneal Osteotomy vs Traditional Evans Osteotomy for Stage IIB Adult-Acquired Flatfoot Deformity.

Science.gov (United States)

Saunders, Stuart M; Ellis, Scott J; Demetracopoulos, Constantine A; Marinescu, Anca; Burkett, Jayme; Deland, Jonathan T

2018-01-01

The forefoot abduction component of the flexible adult-acquired flatfoot can be addressed with lengthening of the anterior process of the calcaneus. We hypothesized that the step-cut lengthening calcaneal osteotomy (SLCO) would decrease the incidence of nonunion, lead to improvement in clinical outcome scores, and have a faster time to healing compared with the traditional Evans osteotomy. We retrospectively reviewed 111 patients (143 total feet: 65 Evans, 78 SLCO) undergoing stage IIB reconstruction followed clinically for at least 2 years. Preoperative and postoperative radiographs were analyzed for the amount of deformity correction. Computed tomography (CT) was used to analyze osteotomy healing. The Foot and Ankle Outcome Scores (FAOS) and lateral pain surveys were used to assess clinical outcomes. Mann-Whitney U tests were used to assess nonnormally distributed data while χ 2 and Fisher exact tests were used to analyze categorical variables (α = 0.05 significant). The Evans group used a larger graft size ( P lengthening. Level III, retrospective cohort study.

Intra-Articular Osteotomy for Distal Humerus Malunion

Directory of Open Access Journals (Sweden)

René K. Marti

2009-01-01

Full Text Available Intra-articular osteotomy is considered in the rare case of malunion after a fracture of the distal humerus to restore humeral alignment and gain a functional arc of elbow motion. Traumatic and iatrogenic disruption of the limited blood flow to the distal end of the humerus resulting in avascular necrosis of capitellum or trochlea is a major pitfall of the this technically challenging procedure. Two cases are presented which illustrate the potential problems of intra-articular osteotomy for malunion of the distal humerus.

Navigation and Image Injection for Control of Bone Removal and Osteotomy Planes in Spine Surgery.

Science.gov (United States)

Kosterhon, Michael; Gutenberg, Angelika; Kantelhardt, Sven Rainer; Archavlis, Elefterios; Giese, Alf

2017-04-01

In contrast to cranial interventions, neuronavigation in spinal surgery is used in few applications, not tapping into its full technological potential. We have developed a method to preoperatively create virtual resection planes and volumes for spinal osteotomies and export 3-D operation plans to a navigation system controlling intraoperative visualization using a surgical microscope's head-up display. The method was developed using a Sawbone ® model of the lumbar spine, demonstrating feasibility with high precision. Computer tomographic and magnetic resonance image data were imported into Amira ® , a 3-D visualization software. Resection planes were positioned, and resection volumes representing intraoperative bone removal were defined. Fused to the original Digital Imaging and Communications in Medicine data, the osteotomy planes were exported to the cranial version of a Brainlab ® navigation system. A navigated surgical microscope with video connection to the navigation system allowed intraoperative image injection to visualize the preplanned resection planes. The workflow was applied to a patient presenting with a congenital hemivertebra of the thoracolumbar spine. Dorsal instrumentation with pedicle screws and rods was followed by resection of the deformed vertebra guided by the in-view image injection of the preplanned resection planes into the optical path of a surgical microscope. Postoperatively, the patient showed no neurological deficits, and the spine was found to be restored in near physiological posture. The intraoperative visualization of resection planes in a microscope's head-up display was found to assist the surgeon during the resection of a complex-shaped bone wedge and may help to further increase accuracy and patient safety. Copyright © 2017 by the Congress of Neurological Surgeons

Postoperative dysesthesia in lumbar three-column resection osteotomies.

Science.gov (United States)

Zhang, Zhengfeng; Wang, Honggang; Zheng, Wenjie

2016-08-01

Three-column lumbar spinal resection osteotomies including pedicle subtraction osteotomy (PSO), vertebral column resection (VCR), and total en bloc spondylectomy (TES) can potentially lead to dorsal root ganglion (DRG) injury which may cause postoperative dysesthesia (POD). The purpose of retrospective study was to describe the uncommon complication of POD in lumbar spinal resection osteotomies. Between January 2009 and December 2013, 64 patients were treated with lumbar three-column spinal resection osteotomies (PSO, n = 31; VCR, n = 29; TES, n = 4) in investigator group. POD was defined as dysesthetic pain or burning dysesthesia at a proper DRG innervated region, whether spontaneous or evoked. Non-steroidal antiinflammatory drugs, central none-opioid analgesic agent, neuropathic pain drugs and/or intervertebral foramen block were selectively used to treat POD. There were 5 cases of POD (5/64, 7.8 %), which consisted of 1 patient in PSO (1/31, 3.2 %), 3 patients in PVCR (3/29, 10.3 %), and 1 patient in TES (1/4, 25 %). After the treatment by drugs administration plus DRG block, all patients presented pain relief with duration from 8 to 38 days. A gradual pain moving to distal end of a proper DRG innervated region was found as the beginning of end. Although POD is a unique and rare complication and maybe misdiagnosed as nerve root injury in lumbar spinal resection osteotomies, combination drug therapy and DRG block have an effective result of pain relief. The appearance of a gradual pain moving to distal end of a proper DRG innervated region during recovering may be used as a sign for the good prognosis.

Periacetabulaer osteotomi og hoftedysplasi hos yngre voksne

DEFF Research Database (Denmark)

Troelsen, Anders; Søballe, Kjeld

2009-01-01

% of cases for more than ten years following surgery. A new minimally invasive technique is safe and reduces blood loss, transfusion requirements and duration of surgery. Overall, the results support the use of periacetabular osteotomy, though further documentation of long-term effects is warranted.......The periacetabular osteotomy is recognized as the surgical treatment of choice in young adults with symptomatic hip dysplasia. The procedure is performed to delay or prevent the development of osteoarthritis. The procedure has the ability to improve function and preserve hip joints in > 80...

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

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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.

Alphabet Soup: Sagittal Balance Correction Osteotomies of the Spine-What Radiologists Should Know.

Science.gov (United States)

Takahashi, T; Kainth, D; Marette, S; Polly, D

2018-04-01

Global sagittal malalignment has been demonstrated to have correlation with clinical symptoms and is a key component to be restored in adult spinal deformity. In this article, various types of sagittal balance-correction osteotomies are reviewed primarily on the basis of the 3 most commonly used procedures: Smith-Petersen osteotomy, pedicle subtraction osteotomy, and vertebral column resection. Familiarity with the expected imaging appearance and commonly encountered complications seen on postoperative imaging studies following correction osteotomies is crucial for accurate image interpretation. © 2018 by American Journal of Neuroradiology.

Piezosurgery versus conventional osteotomy in orthognathic surgery: a paradigm shift in treatment.

Science.gov (United States)

Bertossi, Dario; Lucchese, Alessandra; Albanese, Massimo; Turra, Matteo; Faccioni, Fiorenzo; Nocini, Pierfrancesco; Rodriguez Y Baena, Ruggero

2013-01-01

The aim of the study was to compare in a randomized controlled clinical trial the use of the piezoelectric osteotomy as an alternative to the conventional approach in terms of surgery time, intraoperative blood loss, cut quality, nerve injury, and costs.One hundred ten patients who had orthognathic surgery procedures with bimaxillary osteotomy were divided into 2 groups: group A was treated with a piezosurgery device, and group B, with a reciprocating saw and bur.The piezosurgical bone osteotomy permitted individualized cut designs. The surgical time in group A was reduced, with a mean for the mandibular osteotomy (1 side) between 3 minutes 31 seconds and 5 minutes 2 seconds, whereas in group B, the surgical time was between 7 minutes 23 seconds and 10 minutes 22 seconds. The surgical time in group A for the Le Fort I osteotomy was between 5 minutes 17 seconds and 7 minutes 55 seconds in group A and between 8 minutes 38 seconds and 15 minutes 11 seconds in group B. All patients in group A had a low blood loss (500 mL). Inferior alveolar nerve sensation was retained in 98.2% of group A versus 92.7% in group B at 6 months postoperative testing.Piezoelectric osteotomy reduced surgical time, blood loss, and inferior alveolar nerve injury in bimaxillary osteotomy. Absence of macrovibrations makes the instrument more manageable and easy to use and allows greater intraoperative control with higher safety in cutting in difficult anatomical regions.

Youngswick-Austin versus distal oblique osteotomy for the treatment of Hallux Rigidus.

Science.gov (United States)

Viladot, Antonio; Sodano, Luca; Marcellini, Lorenzo; Zamperetti, Marco; Hernandez, Elsa Sanchez; Perice, Ramon Viladot

2017-08-01

Hallux Rigidus is the most common degenerative joint pathology of the foot. Several procedures are described for the management of this deformity. In this prospective study we compared Youngswick-Austin and distal oblique osteotomy in the treatment of grade II Hallux Rigidus, in terms of clinical outcomes, efficacy and complications. Forty-six patients (50 feet) with moderate Hallux Rigidus (Regnauld grade II) were recruited and operated between March 2009 and December 2012. Surgical technique was Youngswick-Austin osteotomy (Group A) or distal oblique osteotomy (Group B). Mean follow-up was 42.7 ±12.2 (range, 24-70) months. Both groups achieved significant improvement of AOFAS score and first metatarsophalangeal joint range of motion (p value Austin and distal oblique osteotomies provides subjective patient improvement and increases the first metatarsophalangeal joint range of motion. The results of grade II Hallux Rigidus treatment were comparable when using a Youngswick-Austin or distal oblique osteotomy. Level II, prospective comparative study. Copyright © 2017 Elsevier Ltd. All rights reserved.

The history, evolution and basic science of osteotomy techniques

Directory of Open Access Journals (Sweden)

John Dabis

2017-10-01

Full Text Available Abstract Osteotomy techniques date back to Hippocrates circa 415 BC (Jones Hippocrates collected works I, Harvard University Press, Cambridge, 2006; Brorson in Clin Orthop Relat Res 467(7:1907–1914, 2009. There is debate about the best way to divide the bone surgically and which technique yields the best bone regenerate in lengthening; ensuring predictable new bone formation and healing of the osteotomy are the primary goals. We review the history and techniques of the osteotomy and consider the evidence for optimum bone formation. Methods discussed include variants of the ‘drill and osteotome’ technique, use of the Gigli saw and use of a power saw. Differences in bone formation through the different techniques are covered.

Clinical accuracy of a patient-specific femoral osteotomy guide in minimally-invasive posterior hip arthroplasty.

Science.gov (United States)

Schneider, Adrian K; Pierrepont, Jim W; Hawdon, Gabrielle; McMahon, Stephen

2018-04-01

Patient specific guides can be a valuable tool in improving the precision of planned femoral neck osteotomies, especially in minimally invasive hip surgery, where bony landmarks are often inaccessible. The aim of our study was to validate the accuracy of a novel patient specific femoral osteotomy guide for THR through a minimally invasive posterior approach, the direct superior approach (DSA). As part of our routine preoperative planning 30 patients underwent low dose CT scans of their arthritic hip. 3D printed patient specific femoral neck osteotomy guides were then produced. Intraoperatively, having cleared all soft tissue from the postero-lateral neck of the enlocated hip, the guide was placed and pinned onto the posterolateral femoral neck. The osteotomy was performed using an oscillating saw and the uncemented hip components were implanted as per routine. Postoperatively, the achieved level of the osteotomy at the medial calcar was compared with the planned level of resection using a 3D/2D matching analysis (Mimics X-ray module, Materialise, Belgium). A total of 30 patients undergoing uncemented Trinity™ acetabular and TriFit TS™ femoral component arthroplasty (Corin, UK) were included in our analysis. All but one of our analysed osteotomies were found to be within 3 mm from the planned height of osteotomy. In one patient the level of osteotomy deviated 5 mm below the planned level of resection. Preoperative planning and the use of patient specific osteotomy guides provides an accurate method of performing femoral neck osteotomies in minimally invasive hip arthroplasty using the direct superior approach. IV (Case series).

Modified french osteotomy for cubitus varus deformity

International Nuclear Information System (INIS)

Ahmad, I.; Idrees, M.

2007-01-01

To evaluate the outcome of Modified French Osteotomy for correction of cubitus varus deformity. All children, aged 3-12 years, with cubitus varus deformity were included in the study. Pre-operative clinical as well as radiological assessment of upper extremities were done in all cases. Modified French osteotomy was done to correct the deformity. All patients were followed for seven months. Physical examination for the range of motion, scar and post-operative complications were assessed. Antero-posterior and lateral radiographs of the elbow were obtained, and the carrying angles and lateral condylar prominence index were measured and recorded. Out of the total 30 patients, 26 were male and four female. Left side was involved in 24 cases and the right side in six. The average age at the time of osteotomy was seven years (range 3.5-12 years). The average pre-operative carrying angle was 25.2 degree (range 18-30 degree) and the post-operative angle 8.7 degree (range 5-13 degree valgus). The average pre- operative range of motion was 122.6 degree (range 105-135 degree) and the post-operative range 123.86 degree (range 90-135 degree). The average pre-operative lateral condylar prominence index (LCPI) was 175.56 (range 128-232) and the post-operative lateral condylar prominence 156 (range 100-240). Based on Bellmore criteria, 25 patients showed excellent, three good and two a poor result. Modified French technique of supracondylar osteotomy has excellent results in the management of cubitus varus in terms of cosmesis, radiological findings and fewer complications. (author)

Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial.

NARCIS (Netherlands)

Deenik, A.; Mameren, H. van; Visser, E. de; Waal Malefijt, M.C. de; Draijer, F.; Bie, R. de

2008-01-01

BACKGROUND: Chevron osteotomy is a widely accepted osteotomy for correction of hallux valgus.(18) Algorithms were developed to overcome the limitations of distal osteotomies. Scarf osteotomy has become popular as a versatile procedure that should be able to correct most cases of acquired hallux

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.

A Modified Triple Pelvic Osteotomy for the Treatment of Hip Hypoplasia

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Hassan Rahimi

2013-09-01

Full Text Available Background: The prevalence of hip dysplasia is 1 in 1000. Several pelvic osteotomy methods have been developed to prevent early osteoarthritis, such as triple osteotomy. In this study we are going to introduce our new technique that was done on 4 patients with favorable short-term results.   Methods: Four patients underwent triple osteotomy and fixation using a reconstruction plate and early weight bearing was started. Results: The Harris Hip Score, limb length, center-edge angle, and acetabular inclination showed improvement. Conclusion: This modified technique is suggested for corrective surgery on adult dysplastic hips.

Inicial nasal mucosa detachment using piezoelectric device in the Le Fort I osteotomy: A technical note

OpenAIRE

Shinohara, Elio Hitoshi; Kaba, Shajadi Carlos Pardo; Ruiz, Marcelo Martinson; Horikawa, Fernando Kendi

2013-01-01

In maxillary Le Fort I type osteotomy the detachment of the nasal mucosa should be done carefully. Piezoelectric surgery contributed much to increase the safety of osteotomies, despite the initial advantage of minimizing the risk of injury in nervous tissue, mainly in bilateral sagittal split osteotomy; we use the piezoelectric device for the initial detachment of the nasal mucosa in the maxillary osteotomy.

Evaluation of outcome of corrective ulnar osteotomy with bone grafting and annular ligament reconstruction in neglected monteggia fracture dislocation in children.

Science.gov (United States)

Datta, Tanmay; Chatterjee, Nd; Pal, Ananda Kisor; Das, Sunil Kumar

2014-06-01

Neglected Monteggia fracture dislocation in the paediatric age group constitutes significant disability in respect to pain, stiffness, deformity, neurological compromise and restriction of activities of daily living. A longitudinal prospective study was done on 21 children with old Monteggia fracture-dislocation which included 18 cases of Bado type I and 3 cases of Bado type III at the department of orthopaedics, IPGME&R,SSKM hospital, Kolkata, India between 2007 and 2012. All were treated by modified Hirayama corrective osteotomy of ulna with wedge bone grafting along with restoration of its length and reconstruction of annular ligament using Bell Tawse method and fixation of radial head with transcapitellar Kirschner wire. Average follow up period was 5.5 years. Results were evaluated on the basis of 100 point Mayo Elbow Performance Index, radiology and questionnaire. The mean postoperative increase in Mayo Elbow Performance Index score was 30 with average increase in the range of movement by 30o. In three cases, there was subluxation of radial head and in addition one had transient palsy of posterior interosseous nerve. Three cases showed distortion of the radial head which were insignificant functionally. Results of improvement in mean MEPI were analysed by chi-square test and was significant at 0 .01 level of significance. Study showed good results with modified Hirayama osteotomy with annular ligament reconstruction using Bell Tawse procedure which is a more biological option for restoration of elbow biomechanics.

Inicial nasal mucosa detachment using piezoelectric device in the Le Fort I osteotomy: A technical note

Science.gov (United States)

Shinohara, Elio Hitoshi; Kaba, Shajadi Carlos Pardo; Ruiz, Marcelo Martinson; Horikawa, Fernando Kendi

2013-01-01

In maxillary Le Fort I type osteotomy the detachment of the nasal mucosa should be done carefully. Piezoelectric surgery contributed much to increase the safety of osteotomies, despite the initial advantage of minimizing the risk of injury in nervous tissue, mainly in bilateral sagittal split osteotomy; we use the piezoelectric device for the initial detachment of the nasal mucosa in the maxillary osteotomy. PMID:23853472

Inicial nasal mucosa detachment using piezoelectric device in the Le Fort I osteotomy: A technical note

Directory of Open Access Journals (Sweden)

Elio Hitoshi Shinohara

2013-01-01

Full Text Available In maxillary Le Fort I type osteotomy the detachment of the nasal mucosa should be done carefully. Piezoelectric surgery contributed much to increase the safety of osteotomies, despite the initial advantage of minimizing the risk of injury in nervous tissue, mainly in bilateral sagittal split osteotomy; we use the piezoelectric device for the initial detachment of the nasal mucosa in the maxillary osteotomy.

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

Comparison of maxillary stability after Le Fort I osteotomy for occlusal cant correction surgery and maxillary advanced surgery.

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Ueki, Koichiro; Hashiba, Yukari; Marukawa, Kohei; Yoshida, Kan; Shimizu, Chika; Nakagawa, Kiyomasa; Yamamoto, Etsuhide

2007-07-01

To compare postoperative maxillary stability following Le Fort I osteotomy for the correction of occlusal cant as compared with conventional Le Fort I osteotomy for maxillary advancement. The subjects were 40 Japanese adults with jaw deformities. Of these, 20 underwent a Le Fort I osteotomy and intraoral vertical ramus osteotomy (IVRO) to correct asymmetric skeletal morphology and inclined occlusal cant. The other 20 patients underwent a Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO) to advance the maxilla. Lateral and posteroanterior cephalograms were taken postoperatively and assessed statistically. Thereafter, the 2 groups were followed for time-course changes. There was no significant difference between the 2 groups with regard to time-course changes during the immediate postoperative period. This suggests that maxillary stability after Le Fort I osteotomy for cant correction does not differ from that after Le Fort I osteotomy for maxillary advancement.

The treatment of an unstable slipped capital femoral epiphysis by either intracapsular cuneiform osteotomy or pinning in situ: a comparative study.

Science.gov (United States)

Walton, R D M; Martin, E; Wright, D; Garg, N K; Perry, D; Bass, A; Bruce, C

2015-03-01

presentation. Intracapsular osteotomy should be undertaken after a delay of at least 14 days. In our experience, closed epiphyseal reduction is harmful. Cite this article: Bone Joint J 2015;97-B:412-19. ©2015 The British Editorial Society of Bone & Joint Surgery.

Piezoelectric osteotomy in hand surgery: first experiences with a new technique

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Hoigne, Dominik J; Stübinger, Stefan; Kaenel, Oliver Von; Shamdasani, Sonia; Hasenboehler, Paula

2006-01-01

Background In hand and spinal surgery nerve lesions are feared complications with the use of standard oscillating saws. Oral surgeons have started using a newly developed ultrasound bone scalpel when performing precise osteotomies. By using a frequency of 25–29 kHz only mineralized tissue is cut, sparing the soft tissue. This reduces the risk of nerve lesions. As there is a lack of experience with this technique in the field of orthopaedic bone surgery, we performed the first ultrasound osteotomy in hand surgery. Method While performing a correctional osteotomy of the 5th metacarpal bone we used the Piezosurgery® Device from Mectron [Italy] instead of the usual oscillating saw. We will report on our experience with one case, with a follow up time of one year. Results The cut was highly precise and there were no vibrations of the bone. The time needed for the operation was slightly longer than the time needed while using the usual saw. Bone healing was good and at no point were there any neurovascular disturbances. Conclusion The Piezosurgery® Device is useful for small long bone osteotomies. Using the fine tip enables curved cutting and provides an opportunity for new osteotomy techniques. As the device selectively cuts bone we feel that this device has great potential in the field of hand- and spinal surgery. PMID:16611362

Piezoelectric osteotomy in hand surgery: first experiences with a new technique

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Kaenel Oliver Von

2006-04-01

Full Text Available Abstract Background In hand and spinal surgery nerve lesions are feared complications with the use of standard oscillating saws. Oral surgeons have started using a newly developed ultrasound bone scalpel when performing precise osteotomies. By using a frequency of 25–29 kHz only mineralized tissue is cut, sparing the soft tissue. This reduces the risk of nerve lesions. As there is a lack of experience with this technique in the field of orthopaedic bone surgery, we performed the first ultrasound osteotomy in hand surgery. Method While performing a correctional osteotomy of the 5th metacarpal bone we used the Piezosurgery® Device from Mectron [Italy] instead of the usual oscillating saw. We will report on our experience with one case, with a follow up time of one year. Results The cut was highly precise and there were no vibrations of the bone. The time needed for the operation was slightly longer than the time needed while using the usual saw. Bone healing was good and at no point were there any neurovascular disturbances. Conclusion The Piezosurgery® Device is useful for small long bone osteotomies. Using the fine tip enables curved cutting and provides an opportunity for new osteotomy techniques. As the device selectively cuts bone we feel that this device has great potential in the field of hand- and spinal surgery.

Minimizing the Translation Error in the Application of an Oblique Single-Cut Rotation Osteotomy: Where to Cut?

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Dobbe, Johannes G G; Strackee, Simon D; Streekstra, Geert J

2018-04-01

An oblique single cut rotation osteotomy enables correcting angular bone alignment in the coronal, sagittal, and transverse planes, with just a single oblique osteotomy, and by rotating one bone segment in the osteotomy plane. However, translational malalignment is likely to exist if the bone is curved or deformed and the location of the oblique osteotomy is not obvious. In this paper, we investigate how translational malalignment depends on the osteotomy location. We further propose and evaluate by simulation in 3-D, a method that minimizes translational malalignment by varying the osteotomy location and by sliding the distal bone segment with respect to the proximal bone segment within the oblique osteotomy plane. The method is finally compared to what three surgeons achieve by manually selecting the osteotomy location in 3-D virtual space without planning in-plane translations. The minimization method optimized for length better than the surgeons did, by 3.2 mm on average, range (0.1, 9.4) mm, in 82% of the cases. A better translation in the axial plane was achieved by 4.1 mm on average, range (0.3, 14.4) mm, in 77% of the cases. The proposed method generally performs better than subjectively choosing an osteotomy position along the bone axis. The proposed method is considered a valuable tool for future alignment planning of an oblique single-cut rotation osteotomy since it helps minimizing translational malalignment.

Intravenous Tranexamic Acid Decreases Allogeneic Transfusion Requirements in Periacetabular Osteotomy.

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Bryan, Andrew J; Sanders, Thomas L; Trousdale, Robert T; Sierra, Rafael J

2016-01-01

Bernese (Ganz) periacetabular osteotomy is associated with significant blood loss and the need for perioperative transfusion. Tranexamic acid decreases blood loss and minimizes transfusion rates in total joint arthroplasty. However, no reports have described its use in patients undergoing Bernese periacetabular osteotomy. This study reports the use of intravenous tranexamic acid in these patients. The study included 137 patients (150 hips) who underwent isolated periacetabular osteotomy at a single institution between 2003 and 2014. Of these, 68 patients (75 hips) received intravenous tranexamic acid 1 g at the time of incision and 1 g at the time of closure. A group of 69 patients (75 hips) served as control subjects who underwent periacetabular osteotomy without administration of intravenous tranexamic acid. Thromboembolic disease was defined as deep venous thrombosis or pulmonary embolism occurring within 6 weeks of surgery. Outcomes measured included transfusion requirements, pre- and postoperative hemoglobin values, operative times, and thromboembolic disease rates. Aspirin was used as the thromboembolic prophylactic regimen in 95% of patients. The rate of allogeneic transfusion was 0 in the tranexamic acid group compared with 21% in the control group (P=.0001). No significant difference was found in the autologous cell salvage requirement (.96 vs 1.01; P=.43) or the thromboembolic disease rate between the tranexamic acid group and the control group (2.67% vs 1.33%; P=.31). The use of intravenous tranexamic acid led to a decreased transfusion requirement with no increased risk of thromboembolic disease in this contemporary cohort of patients undergoing periacetabular osteotomy. Copyright 2016, SLACK Incorporated.

Electromagnetic Scattering from a PEC Wedge Capped with Cylindrical Layers with Dielectric and Conductive Properties

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H. Ozturk

2017-04-01

Full Text Available Electromagnetic scattering from a layered capped wedge is studied. The wedge is assumed infinite in z-direction (longitudinal and capped with arbitrary layers of dielectric with varying thicknesses and dielectric properties including conductive loss. Scalar Helmholtz equation in two dimensions is formulated for each solution region and a matrix of unknown coefficients are arrived at for electric field representation. Closed form expressions are derived for 2- and 3-layer geometries. Numerical simulations are performed for different wedge shapes and dielectric layer properties and compared to PEC-only case. It has been shown that significant reduction in scattered electric field can be obtained with 2- and 3-layered cap geometries. Total electric field in the far field normalized to incident field is also computed as a precursor to RCS analysis. Analytical results can be useful in radar cross section analysis for aerial vehicles.

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)

Lengthening of the shortened first metatarsal after Wilson's osteotomy for hallux valgus.

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Singh, D; Dudkiewicz, I

2009-12-01

Metatarsalgia is a recognised complication following iatrogenic shortening of the first metatarsal in the management of hallux valgus. The traditional surgical treatment is by shortening osteotomies of the lesser metatarsals. We describe the results of lengthening of iatrogenic first brachymetatarsia in 16 females. A Scarf-type osteotomy was used in the first four cases and a step-cut of equal thicknesses along the axis of the first metatarsal was performed in the others. The mean follow-up was 21 months (19 to 26). Relief of metatarsalgia was obtained in the six patients in whom 10 mm of lengthening had been achieved, compared to only 50% relief in those where less than 8 mm of lengthening had been gained. One-stage step-cut lengthening osteotomy of the first metatarsal may be preferable to shortening osteotomies of the lesser metatarsals in the treatment of metatarsalgia following surgical shortening of the first metatarsal.

Acetabular osteotomy for double boarding in lateral decubitus. Anatomical bases and surgical technique

International Nuclear Information System (INIS)

Lazennec, J Y; Del Vecchio, R; Saillant, G

2001-01-01

The periacetabular osteotomies of reorientation of the eotilo have a reputation of being difficult from the technical point of view. The authors present a technique of juxta acetabular osteotomy that respects the posterior column of the acetabulo the same as the GANZ technique. The osteotomy is of simpler realization thanks to an installation that allows carrying out two simultaneous boarding. The osteotomy lines, their rectilinear and controllable in permanency through of images intensificator and they don't constitute any risk for the essential vascular contribution of the obturatriz artery and their branches. Their other interest comes represented by the possibility of correcting easily the parasitic retroversion associated to the descent of the whole eotilo, that it allows to avoid the bad positions that they affect the center of the articulation and the widths acetabular

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)

Miniplate fixation of Le Fort I osteotomies.

Science.gov (United States)

Rosen, H M

1986-12-01

The use of rigid, internal, three-dimensional fixation using vitallium bone plates in 28 consecutive Le Fort I osteotomies is presented. A minimum follow-up period of 6 months was required for inclusion in this patient group. Maxillary movements included advancements (17), intrusions (9), lengthenings (5), and retrusions (2). The majority of maxillae were moved in more than one plane of space. Technical details, complications, and relapse potential are discussed. Advantages of rigid plate fixation include marked reductions in the length of intermaxillary fixation with light training elastics only. Immediate postoperative airway problems are thereby eliminated. Six months of follow-up would appear to indicate a low potential for osseous relapse when compared to wire osteosynthesis, regardless of the direction of maxillary movement. The major disadvantage is the decreased ability of postoperative orthodontics to move dento-osseous segments if skeletal occlusal disharmony persists postoperatively. For this reason, close attention to preoperative planning and operative technique is critical for the success of this fixation method.

Mantle wedge serpentinization effects on slab dips

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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.

Outcomes of a Stepcut Lengthening Calcaneal Osteotomy for Adult-Acquired Flatfoot Deformity.

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Demetracopoulos, Constantine A; Nair, Pallavi; Malzberg, Andrew; Deland, Jonathan T

2015-07-01

Lateral column lengthening is used to correct abduction deformity at the midfoot and improve talar head coverage in patients with flatfoot deformity. It was our hypothesis that following a stepcut lengthening calcaneal osteotomy (SLCO), patients would have adequate correction of the deformity, a high union rate of the osteotomy, and improvement in clinical outcome scores. We retrospectively reviewed 37 consecutive patients who underwent SLCO for the treatment of stage IIB flatfoot deformity with a minimum 2-year follow-up. Deformity correction was assessed using preoperative and postoperative weight-bearing radiographs. Healing of the osteotomy was assessed by computed tomography. Clinical outcomes included the FAOS and SF-36 questionnaires. The Wilcoxon signed-rank test was used to compare clinical outcome scores. An alpha level of .05 was deemed statistically significant. Healing of the osteotomy occurred at a mean of 7.7 weeks postoperatively. The talonavicular (TN) coverage angle improved from 34.0 to 8.8 (P lengthening. Level IV, retrospective case review. © The Author(s) 2015.

Evaluation of recovery in lip closing pressure and occlusal force and contact area after orthognathic surgery.

Science.gov (United States)

Ueki, Koichiro; Moroi, Akinori; Sotobori, Megumi; Ishihara, Yuri; Marukawa, Kohei; Iguchi, Ran; Kosaka, Akihiko; Ikawa, Hiroumi; Nakazawa, Ryuichi; Higuchi, Masatoshi

2014-10-01

The purpose of this study was to evaluate the relationship between lip closing force, occlusal contact area and occlusal force after orthognathic surgery in skeletal Class III patients. The subjects consisted of 54 patients (28 female and 26 male) diagnosed with mandibular prognathism who underwent sagittal split ramus osteotomy with and without Le Fort I osteotomy. Maximum and minimum lip closing forces, occlusal contact area and occlusal force were measured pre-operatively, 6 months and 1 year post-operative. Maximum and minimum lip closing forces, occlusal contact area and occlusal force increased with time after surgery, however a significant increase was not found in the occlusal contact area in women. In increased ratio (6 months/pre-operative and 1 year/pre-operative), the maximum lip closing force was significantly correlated with the occlusal contact area (P contact area and lip closing force, and an increase ratio in maximum lip closing force was associated with an increased ratio in occlusal contact area. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Torsional osteotomies of the tibia in patellofemoral dysbalance.

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Dickschas, Jörg; Tassika, Aliki; Lutter, Christoph; Harrer, Jörg; Strecker, Wolf

2017-02-01

Anterior knee pain or patellofemoral instability is common symptom of patellofemoral dysbalance or maltracking. Tibial torsional deformities can be the reason of this pathology. After appropriate diagnostic investigation, the treatment of choice is a torsional osteotomy. This study addresses the diagnostic investigation, treatment, and the outcome of torsional osteotomies of the tibia. Does this treatment result in patellofemoral stability and provide pain relief? Forty-nine tibial torsional osteotomies were included. The major symptoms were patellofemoral instability in 19 cases and anterior knee pain in 42 cases. In addition to clinical and radiographic analysis, a torsional angle CT scan was performed pre-operatively. A visual analog scale (VAS), the Japanese Knee Society score, the Tegner activity score, and the Lysholm score were assessed pre-operatively and at the 42-month follow-up. Mean tibial external torsion was 47.4° (SD 5.41; range 37°-66°; standard value 34°). Surgical treatment consisted of an acute supratuberositary tibial internal torsional osteotomy (mean 10.8°; SD 3.01°; range 5°-18°). At the follow-up investigation, the Tegner activity score was increased 0.4 points (p value 0.014) from 3.9 (SD 1.33; range 2-7) to 4.3 (SD 1.25; range 0-7). The Lysholm score increased 26 points (SD 16.32; p value 0.001) from 66 (SD 14.94; range 32-94) to 92 (SD 9.29; range 70-100) and the Japanese Knee Society score increased 18 points (SD 14.70; p value 0.001) from 72 (SD 13.72, range 49-100) to 90 (SD 9.85, range 60-100). VAS was reduced 3.4 points (SD 2.89; p value 0.001) from 5.7 (SD 2.78; range 0-10) to 2.3 (SD 1.83; range 0-7). As regards patellofemoral instability, no redislocation occurred in the follow-up period. The results of this study show that in cases of tibial maltorsion, a torsional osteotomy can lead to patellofemoral stability and pain relief, and should be considered as a treatment option. The improved clinical scores in the present

Intraoperative blood loss in bimaxillary orthognathic surgery with multisegmental Le Fort I osteotomies and additional procedures.

Science.gov (United States)

Kretschmer, W B; Baciut, G; Bacuit, Mihaela; Zoder, W; Wangerin, K

2010-06-01

Autologous blood donation is not currently recommended by most authors for routine bimaxillary osteotomies. There are few data about bimaxillary procedures with multisegmental maxillary osteotomies. Our aim was to investigate the effect of additional osteotomies and iliac crest grafts on operative blood loss. A total of 225 consecutive patients having bimaxillary multisegmental osteotomies during a three-year period (January 2006-January 2009) were examined to see if their haemoglobin concentration and packed cell volume were reduced. The influence of iliac crest grafts, additional osteotomies (genioplasty, malar osteotomy, iliac crest graft, anterior mandibular segmental osteotomy), operating time, age, and sex were assessed. Neither age nor sex influenced blood loss, whereas operating time correlated significantly with reductions in haemoglobin concentration and packed cell volume. Blood loss was significantly higher in the group who had additional procedures (p 0.001 for haemoglobin concentration and packed cell volume) than in the group who had no additional procedures, whereas there were no significant differences among the three subgroups who had additional procedures (additional osteotomies, iliac crest grafts, or both procedures). Four patients who had additional procedures required transfusion, whereas no blood was given in the group who had no additional procedures. Because the transfusion rate was so low, we could make no general recommendation for preoperative blood donation in such cases. Copyright 2009 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study.

Science.gov (United States)

Delgado-Ruiz, R A; Sacks, D; Palermo, A; Calvo-Guirado, J L; Perez-Albacete, C; Romanos, G E

2016-09-01

The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks. Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed. Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P  0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[APPLICATION OF PHOTOSHOP CS16.0 SOFTWARE IN PREOPERATIVE OSTEOTOMY DESIGN OF ANKYLOSING SPONDYLITIS KYPHOSIS].

Science.gov (United States)

Wang, Fei; Tao, Huiren; Liu, Zhibin; Zhang, Jianhua; Han, Fangmin

2015-02-01

To introduce the application of Photoshop CS16.0 (PS) software in preoperative osteotomy design of ankylosing spondylitis kyphosis (ASK), and to investigate applied values of the preoperative design. Between March 2009 and March 2013, 21 cases of ASK were treated through preoperative osteotomy design by using PS software. There were 16 males and 5 females, aged from 23 to 50 years (mean, 34.2 years). The deformity included thoracolumbar kyphosis in 14 cases, thoracic kyphosis in 2 cases, and lumbar kyphosis in 5 cases. The ultimate osteotomy angle of preoperative plans and the location and extent of osteotomy were determined by the osteotomy design, which guided operation procedures of the surgeon. The actual osteotomy angle was obtained by measuring Cobb angle of osteotomy segment before and after operation. The sagittal parameters of spine and pelvis including global kyphosis (GK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and chin brow-vertical angle (CBVA) were measured at preoperation, at 1 week after operation, and last follow-up. The clinical outcomes were assessed by simplified Chinese Scoliosis Research Society-22 (SRS-22) questionnaire and Oswestry disability index (ODI). No complications occurred in the other cases except 1 case of dural tear during operation and 1 case of nerve injury after operation, and primary healing of incision was obtained. All patients were followed up 14 to 45 months (mean, 26.3 months). The SRS-22 and ODI scores at 1 week after operation and last follow-up were significantly improved when compared with preoperative scores (P 0.05). The preoperative planned osteotomy angle and the postoperative actual osteotomy angle were (34.2 ± 10.5) degrees and (33.7 ± 9.7) degrees respectively, showing no significant difference (t = 0.84, P = 0.42). The CBVA, GK, SVA, PT, and LL were significantly improved when compared with the preoperative values (P 0.05). At last follow-up, no failures

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...

The Gibson and Piggott osteotomy for adult hallux valgus.

Science.gov (United States)

Rangrez, Arshad Bashir; Dar, Tahir Ahmed; Badoo, Abdul Rashid; Wani, Sharief Ahmed; Dhar, Shabir Ahmed; Mumtaz, Imran; Ahmed, Muzzaffar

2012-01-01

The Gibson and Piggott procedure for hallux valgus is based on sound surgical principles addressing the basic pathologies of this disorder. However, this procedure has not been studied extensively in the literature in comparison to the Mitchell and Chevron osteotomies. We report a prospective study conducted on 50 adult feet with hallux valgus. The Gibson and Piggot osteotomy was done on all the feet. We obtained 76% excellent and 18% good results with this procedure. The results bear out the fact that this procedure is a useful procedure for the management of this disorder.

Posterior trochanteric osteotomy in acetabular fractures for 32 cases.

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Niu, Yunfei; An, Xiaofei; Xu, Shuogui; Wu, Dajiang; Zhang, Chuncai; Li, Ming

2014-11-01

The aim of this study is to explore the method and clinical outcome of posterior trochanteric osteotomy in acetabular fractures. From January 2000 to January 2008, 32 cases of acetabular fractures involving the dome of acetabulum underwent posterior trochanteric osteotomy for a better exposure and internal fixation with acetabular tridimensional memory fixation system. 28 cases (16 men and 12 women, mean age 39.9 years, range 16-73 years) were followed up with an average of 48.9 months (range of 19-95 months) and four were lost during follow up. Of 28 cases, 19 were fresh fractures and 9 were old fractures. The reduction was evaluated with Matta criteria. Clinical evaluation was based on modified Merle d'Aubigne and Postel scoring. Motor strength of the abductors was evaluated according to the Medical Research Council grading system. Ectopic ossification was classified according to Brooker criteria. Anatomical reduction was achieved in 17 cases and satisfied reduction in 10 patients. Poor reduction happened in an old fracture. All acetabular fractures got a direct bone union and no displacement and deep infection occurred. All osteotomies healed within 3.5 months without any nonunion, proximal migration of the greater trochanter, loosing or broken of instrumentation, and deep infection. Two superficial infections were healed with a regular dressing. Two patients underwent removal of implants from greater trochanter because of irritation. The strength of the abductors was of Grade 3/5 in two patients, Grade 4/5 in five patients, and normal in the rest. Clinical scoring was excellent to good in 84 %. Ectopic ossification occurred in five patients, grade 1 in two patients, grade 2 in two, and grade 3 in one. But function of hip joint was not seriously affected. Posterior trochanteric osteotomy can provide an adequate exposure of the dome of acetabulum without the associated complications like nonunion, proximal replacement, and weak of the abductors which often occur

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

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

Application of a novel bone osteotomy plate leads to reduction in heat-induced bone tissue necrosis in sheep.

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Bekić, Marijo; Davila, Slavko; Hrskanović, Mato; Bekić, Marijana; Seiwerth, Sven; Erdeljić, Viktorija; Capak, Darko; Butković, Vladimir

2008-12-01

Previous studies have shown substantial effect thermal damage can have on new bone formation following osteotomy. In this study we evaluated the extent of thermal damage which occurs in four different methods of osteotomy and the effects it can have on bone healing. We further wanted to test whether a special osteotomy plate we constructed can lead to diminished heat generation during osteotomy and enhanced bone healing. The four methods evaluated included osteotomy performed by chisel, a newly constructed osteotomy plate, Gigly and oscillating saw. Twelve adult sheep underwent osteotomy performed on both tibiae. Bone fragments were stabilized using a fixation plate. Callus size was assessed using standard radiographs. Densitometry and histological evaluation were performed at 8 weeks following osteotomy. Temperature measurements were performed both in vivo during the operation, and ex vivo on explanted tibiae. The defects healed without complications and showed typical course of secondary fracture healing with callus ingrowth into the osteotomy gap. Radiographic examination of bone healing showed a tendency towards more callus formation in bones osteotomized using Gigly and oscillating saw, but this difference lacked significance. Use of Gigly and oscillating saw elicited much higher temperatures at the bone cortex surface, which subsequently lead to slightly impaired bone healing according to histological analysis. BMD was equal among all bones. In conclusion, the time required for complete healing of the defect differed depended greatly on the instruments used. The newly constructed osteotomy plate showed best results based on histological findings of capillary and osteoblast density.

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

Minimizing the translation error in the application of an oblique single-cut rotation osteotomy: Where to cut?

NARCIS (Netherlands)

Dobbe, Johannes G. G.; Strackee, Simon D.; Streekstra, Geert J.

2017-01-01

An oblique single cut rotation osteotomy enables correcting angular bone alignment in the coronal, sagittal and transverse planes, with just a single oblique osteotomy, and by rotating one bone segment in the osteotomy plane. However, translational malalignment is likely to exist if the bone is

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.

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)

The influence of foot geometry on the calcaneal osteotomy angle based on two-dimensional static force analyses

NARCIS (Netherlands)

Reilingh, M.L.; Tuijthof, G.J.M.; Van Dijk, C.N.; Blankevoort, L.

2011-01-01

Background: Malalignment of the hindfoot can be corrected with a calcaneal osteotomy (CO). A well-selected osteotomy angle in the sagittal plane will reduce the shear force in the osteotomy plane while walking. The purpose was to determine the presence of a relationship between the foot geometry and

The influence of foot geometry on the calcaneal osteotomy angle based on two-dimensional static force analyses

NARCIS (Netherlands)

Reilingh, M. L.; Tuijthof, G. J. M.; van Dijk, C. N.; Blankevoort, L.

2011-01-01

Malalignment of the hindfoot can be corrected with a calcaneal osteotomy (CO). A well-selected osteotomy angle in the sagittal plane will reduce the shear force in the osteotomy plane while walking. The purpose was to determine the presence of a relationship between the foot geometry and loading of

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

Biomechanical consequences of adding plantar fascia release to metatarsal osteotomies: Changes in forefoot plantar pressures.

Science.gov (United States)

Aydogan, Umur; Roush, Evan P; Moore, Blake E; Andrews, Seth H; Lewis, Gregory S

2017-04-01

Destruction of the normal metatarsal arch by a long metatarsal is often a cause for metatarsalgia. When surgery is warranted, distal oblique, or proximal dorsiflexion osteotomies of the long metatarsal bones are commonly used. The plantar fascia has anatomical connection to all metatarsal heads. There is controversial scientific evidence on the effect of plantar fascia release on forefoot biomechanics. In this cadaveric biomechanical study, we hypothesized that plantar fascia release would augment the plantar metatarsal pressure decreasing effects of two common second metatarsal osteotomy techniques. Six matched pairs of foot and ankle specimens were mounted on a pressure mat loading platform. Two randomly assigned surgery groups, which had received either distal oblique, or proximal dorsiflexion osteotomy of the second metatarsal, were evaluated before and after plantar fasciectomy. Specimens were loaded up to a ground reaction force of 400 N at varying Achilles tendon forces. Average pressures, peak pressures, and contact areas were analyzed. Supporting our hypothesis, average pressures under the second metatarsal during 600 N Achilles load were decreased by plantar fascia release following proximal osteotomy (p plantar fascia release following modified distal osteotomy, under multiple Achilles loading conditions (p Plantar fasciotomy should not be added to distal metatarsal osteotomy in the treatment of metatarsalgia. If proximal dorsiflexion osteotomy would be preferred, plantar fasciotomy should be approached cautiously not to disturb the forefoot biomechanics. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:800-804, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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

Mini-Invasive floating metatarsal osteotomy for resistant or recurrent neuropathic plantar metatarsal head ulcers.

Science.gov (United States)

Tamir, Eran; Finestone, Aharon S; Avisar, Erez; Agar, Gabriel

2016-07-11

Patients with peripheral neuropathy and pressure under a relatively plantar deviated metatarsal head frequently develop plantar foot ulcers. When conservative management with orthotics and shoes does not cure the ulcer, surgical metatarsal osteotomy may be indicated to relieve the pressure and enable the ulcer to heal. The purpose of this study is to evaluate the use of a mini-invasive floating metatarsal osteotomy in treating recalcitrant ulcers or recurrent ulcers plantar to the metatarsal heads in patients with diabetes mellitus (DM) related neuropathy. Computerized medical files of patients with diabetic neuropathy treated with an osteotomy during 2013 and 2014 were retrospectively reviewed. There were 20 osteotomies performed on 17 patients (mean age 58 years). The patients had a diagnosis of DM for a mean of 17 years. All ulcers were University of Texas grade 1A; mean ulcer age was 19 months. After 17/20 operations, the ulcer completely resolved after 6 weeks and did not recur after a mean follow-up of 11.5 months. One patient developed an early post-operative infection with osteomyelitis at the osteotomy site (proximal shaft of the fifth metatarsal) that needed debridement and IV antibiotics. In the other 19 cases, the surgical wound healed within 1 week. Asymptomatic radiological non-union developed in six cases (30 %). Mini-invasive floating metatarsal osteotomy can cure resistant and recurrent University of Texas grade 1A ulcerations plantar to the metatarsal heads in neuropathic patients.

Comparison between piezosurgery and conventional osteotomy in cranioplasty with fronto-orbital advancement.

Science.gov (United States)

Martini, Markus; Röhrig, Andreas; Reich, Rudolf Hermann; Messing-Jünger, Martina

2017-03-01

Cranioplasty of patients with craniosynostosis requires rapid, precise and gentle osteotomy of the skull to avoid complications and benefit the healing process. The aim of this prospective clinical study was to compare two different methods of osteotomy. Piezosurgery and conventional osteotomy were compared using an oscillating saw and high speed drill while performing cranioplasties with fronto-orbital advancement. Thirty-four children who required cranioplasty with fronto-orbital advancement were recruited consecutively. The operations were conducted using piezosurgery or a conventional surgical technique, alternately. Operative time, blood count, CRP and transfusion rate, as well as soft tissue injuries, postoperative edema, pain development and secondary bone healing were investigated. The average age of patients was 9.7 months. The following indications for craniosynostosis were surgically corrected: trigonocephaly (23), anterior plagiocephaly (8), brachycephaly (1), and syndromic craniosynostosis (2). Piezosurgery was utilized in 18 cases. There were no group differences with regard to the incidence of soft tissue injuries (dura, periorbita), pain, swelling, blood loss or bony integration. The duration of osteotomy was significantly longer in the piezosurgery group, leading to slightly increased blood loss, while the postoperative CRP increase was higher using the conventional method. The piezosurgery method is a comparatively safe surgical method for conducting osteotomy during cranioplasty. With regard to soft tissue protection and postoperative clinical course, the same procedural precautions and controls are necessary as those needed for conventional methods. The osteotomy duration is considerably longer using piezosurgery, although it is accompanied by lower initial postoperative CRP values. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Valgus osteotomy of the tibia with a Puddu plate combined with anterior cruciate ligament reconstruction

Directory of Open Access Journals (Sweden)

Albuquerque Roberto Freire da Mota e

2003-01-01

Full Text Available Anterior knee instability associated with a varus deformity is a complex condition with several treatment possibilities. Among these, anterior cruciate ligament (ACL associated to a simultaneous valgus tibial osteotomy is a increasing indication. This simultaneous procedure adds technical issues to those related to the isolated surgeries. Thus, the osteotomy plane and location of fixation hardware shouldn?t conflict with tibial tunnel and ACL graft fixation. Authors analyze the relations between a opening tibial valgus osteotomy stabilized with a Puddu plate and ACL reconstruction with a patellar tendon graft fixated with interference screws in 10 human cadaver knees. A straight oblique tibial osteotomy starting on the medial tibial cortex and oriented laterally and proximally was performed on all knees with a 10mm opening medially and stabilized with a Puddu plate on the most posterior aspect of the medial tibia, and a tibial tunnel drilled 50° to tibial plateau. With this technique there was no intersection between tibial tunnel or interference screw and the osteotomy or the plate fixation screws.

Radiographic evaluation for AVN following distal metatarsal Stoffella bunion osteotomy.

Science.gov (United States)

Klein, Christian; Zembsch, Alexander; Dorn, Ulrich

2009-01-01

Avascular necrosis of the metatarsal head, delayed bone healing and nonunion are complications that may occur after distal first metatarsal osteotomies. Intraoperative damage to the extraosseous blood supply, the location of the osteotomy and postoperative vasospasm have been cited as possible causes of such changes. We evaluated Stoffella's subcapital osteotomies which were performed at our department for the correction of moderate to severe hallux valgus deformities. Standardized radiographs of 300 feet, taken 6weeks, 3 months, and 6 months postoperatively and at the final followup were examined with regard to postoperative AVN or signs of delayed bone healing. Of 228 patients, 202 were women and 26 were men. The patients' mean age was 49 years, and the mean followup was 12 months. In 278 cases the radiographs revealed an unremarkable first metatarsal head. Seventeen cases showed diffuse or localized osteopenia or small cysts in the subchondral bone. These changes fully resolved on subsequent radiographs. The X-rays of two patients revealed progressive narrowing of the joint space, irregular contours on the surface of the joint and an abnormal bone structure. The patients subsequently developed a characteristic picture of avascular necrosis, in one case combined with nonunion. Three patients had delayed bone healing, but ultimately healed successfully. Ischemic changes in bone are known to occur after distal first metatarsal osteotomies. There is a very low incidence of postoperative perfusion problems after Stoffella;s technique, even with lateral soft tissue release.

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

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

[Biomechanical study of internal midface distraction after different types of maxillary osteotomy in patients with cleft lip and palate].

Science.gov (United States)

Hou, Min; Shi, Guang-Yu; Pu, Li-Chen; Song, Da-Li; Zhang, Xi-Zhong; Liu, Chun-Ming

2009-09-01

To investigate the biomechanical changes of internal midface distraction after different types of maxillary osteotomy in patients with cleft lip and palate (CLP). 3-D finite element (FEM) analysis was used. 3-D models of Le Fort I, II, III osteotomy and soft tissue were established. Based on the new pattern of internal midface distractor, the distraction of maxillary complex was simulated to advance 10 mm anteriorly. The mechanical change was studied. The maxillary complex in CLP were advanced after distraction. Constriction of alveolar crest and palate occurred in Le Fort I osteotomy, but not in Le Fort II and III osteotomy. The maxillary complex was moved anteriorly en bloc after Le Fort III osteotomy, but some degree of rotation of maxillary complex was observed during the distraction after Le Fort I and II osteotomy. In vertical direction, the maxillary complex had more counterclockwise rotation after Le Fort II osteotomy. 3-D FEM analysis can be used for the study of internal distraction. It can reflect the maxillary movement and provide the theory basis for preoperative design.

Experimental Fracture Model versus Osteotomy Model in Metacarpal Bone Plate Fixation

Directory of Open Access Journals (Sweden)

S. Ochman

2011-01-01

Full Text Available Introduction. Osteotomy or fracture models can be used to evaluate mechanical properties of fixation techniques of the hand skeleton in vitro. Although many studies make use of osteotomy models, fracture models simulate the clinical situation more realistically. This study investigates monocortical and bicortical plate fixation on metacarpal bones considering both aforementioned models to decide which method is best suited to test fixation techniques. Methods. Porcine metacarpal bones (=40 were randomized into 4 groups. In groups I and II bones were fractured with a modified 3-point bending test. The intact bones represented a further control group to which the other groups after fixation were compared. In groups III and IV a standard osteotomy was carried out. Bones were fixated with plates monocortically (group I, III and bicortically (group II, IV and tested for failure. Results. Bones fractured at a mean maximum load of 482.8 N ± 104.8 N with a relative standard deviation (RSD of 21.7%, mean stiffness was 122.3 ± 35 N/mm. In the fracture model, there was a significant difference (=0.01 for maximum load of monocortically and bicortically fixed bones in contrast to the osteotomy model (=0.9. Discussion. In the fracture model, because one can use the same bone for both measurements in the intact state and the bone-plate construct states, the impact of inter-individual differences is reduced. In contrast to the osteotomy model there are differences between monocortical and bicortical fixations in the fracture model. Thus simulation of the in vivo situation is better and seems to be suitable for the evaluation of mechanical properties of fixation techniques on metacarpals.

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.

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

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

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.

Predicted osteotomy planes are accurate when using patient-specific instrumentation for total knee arthroplasty in cadavers: a descriptive analysis.

Science.gov (United States)

Kievit, A J; Dobbe, J G G; Streekstra, G J; Blankevoort, L; Schafroth, M U

2018-06-01

Malalignment of implants is a major source of failure during total knee arthroplasty. To achieve more accurate 3D planning and execution of the osteotomy cuts during surgery, the Signature (Biomet, Warsaw) patient-specific instrumentation (PSI) was used to produce pin guides for the positioning of the osteotomy blocks by means of computer-aided manufacture based on CT scan images. The research question of this study is: what is the transfer accuracy of osteotomy planes predicted by the Signature PSI system for preoperative 3D planning and intraoperative block-guided pin placement to perform total knee arthroplasty procedures? The transfer accuracy achieved by using the Signature PSI system was evaluated by comparing the osteotomy planes predicted preoperatively with the osteotomy planes seen intraoperatively in human cadaveric legs. Outcomes were measured in terms of translational and rotational errors (varus, valgus, flexion, extension and axial rotation) for both tibia and femur osteotomies. Average translational errors between the osteotomy planes predicted using the Signature system and the actual osteotomy planes achieved was 0.8 mm (± 0.5 mm) for the tibia and 0.7 mm (± 4.0 mm) for the femur. Average rotational errors in relation to predicted and achieved osteotomy planes were 0.1° (± 1.2°) of varus and 0.4° (± 1.7°) of anterior slope (extension) for the tibia, and 2.8° (± 2.0°) of varus and 0.9° (± 2.7°) of flexion and 1.4° (± 2.2°) of external rotation for the femur. The similarity between osteotomy planes predicted using the Signature system and osteotomy planes actually achieved was excellent for the tibia although some discrepancies were seen for the femur. The use of 3D system techniques in TKA surgery can provide accurate intraoperative guidance, especially for patients with deformed bone, tailored to individual patients and ensure better placement of the implant.

Osteotomy around young deformed knees: 38-year super-long-term follow-up to detect osteoarthritis.

Science.gov (United States)

Koshino, Tomihisa

2010-02-01

Since 1969 corrective osteotomy has been performed at our institute in young patients (under 40 years) with bowlegs, knock knees and flexion or rotational deformities around the knee. Fifty-seven knees (29 left, 28 right) of 45 patients (19 boys, 26 girls) were followed-up for a period ranging from 30 to 38 years in seven patients with seven knees, from 20 to 29 years in nine patients with 11 knees, and from ten to 19 years in 29 patients with 39 knees. Supracondylar femoral osteotomy was performed on 12 knees (11 patients), high tibial osteotomy above the tibial tuberosity on eight knees (six patients) and below the tuberosity on 37 knees (28 patients). At the final follow-up (age range 42-73 years), all of the deformities were satisfactorily corrected, with no symptoms apart from nine knees, seven of which had dull pain after strenuous sport with osteophytes, etc. in the radiograph. Total knee arthroplasty was performed in the remaining two knees, at ten and 26 years, respectively, after the initial osteotomy. Osteoarthritis developed in the contralateral knee to the initial osteotomy in two patients after 34 years at age 73 and after 33 years at age 67.

Patellofemoral dysbalance and genua valga: outcome after femoral varisation osteotomies.

Science.gov (United States)

Dickschas, Jörg; Ferner, Felix; Lutter, Christoph; Gelse, Kolja; Harrer, Jörg; Strecker, Wolf

2018-01-01

Patellofemoral dysbalance may be caused by trochlear dysplasia, an elevated TTTG distance, femoral or tibial torsional deformities, patella alta, or a genu valgum. The surgical procedure for the treatment of a genu valgum is varisation osteotomy, usually in the femoral aspect. Several authors believe that a genu valgum is one cause of patellofemoral dysbalance, but studies about the outcome of the treatment with a varisation osteotomy are rare. Nineteen knees in 18 patients, aged on average 28 (16-52) years were investigated in a retrospective study. The patients had symptoms of patellofemoral instability or anterior knee pain due to a genu valgum, without symptoms of a lateral femorotibial compartment. All patients underwent a femoral varisation osteotomy. The diagnostic investigation prior to surgery included full-leg radiographs and torsional angle CT scans. The pre-surgery and follow-up investigation included the visual analog scale (VAS), the Kujala score, the Japanese Knee Society score, the Lysholm score. The mean duration of follow-up was 44(10-132) months. The mean preoperative mechanical valgus was 5.6° (range 4-10°). Twelve patients mentioned patellar instability as the main symptom while 14 mentioned anterior knee pain. No redislocation occurred in the follow-up period. Anterior knee pain on the VAS (p value patellofemoral dysbalance, treatment of this condition is femoral varisation osteotomy. In this study, patellofemoral stability was achieved and anterior knee pain was significantly reduced. Significant improvements in clinical scores proved the success of the treatment. IV, case series.

Proximal supination osteotomy of the first metatarsal for hallux valgus.

Science.gov (United States)

Yasuda, Toshito; Okuda, Ryuzo; Jotoku, Tsuyoshi; Shima, Hiroaki; Hida, Takashi; Neo, Masashi

2015-06-01

Risk factors for hallux valgus recurrence include postoperative round-shaped lateral edge of the first metatarsal head and postoperative incomplete reduction of the sesamoids. To prevent the occurrence of such conditions, we developed a proximal supination osteotomy of the first metatarsal. Our aim was to describe this novel technique and report the outcomes in this report. Sixty-six patients (83 feet) underwent a distal soft tissue procedure combined with a proximal supination osteotomy. After the proximal crescentic osteotomy, the proximal fragment was pushed medially, and the distal fragment was abducted, and then the distal fragment of the first metatarsal was manually supinated. Outcomes were assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) score and radiographic examinations. The average follow-up duration was 34 (range, 25 to 52) months. The mean AOFAS score improved significantly from 58.0 points preoperatively to 93.8 points postoperatively (P hallux valgus and intermetatarsal angle decreased significantly from 38.6 and 18.0 degrees preoperatively to 11.0 and 7.9 degrees postoperatively, respectively (both, P hallux valgus, defined as a hallux valgus angle ≥ 25 degrees. The rates of occurrence of a positive round sign and incomplete reduction of the sesamoids significantly decreased postoperatively, which may have contributed to the low hallux valgus recurrence rates. We conclude that a proximal supination osteotomy was an effective procedure for correction of hallux valgus and can achieve a low rate of hallux valgus recurrence. Level IV, retrospective case series. © The Author(s) 2015.

Periacetabulaer osteotomi og hoftedysplasi hos yngre voksne

DEFF Research Database (Denmark)

Troelsen, Anders; Søballe, Kjeld

2009-01-01

The periacetabular osteotomy is recognized as the surgical treatment of choice in young adults with symptomatic hip dysplasia. The procedure is performed to delay or prevent the development of osteoarthritis. The procedure has the ability to improve function and preserve hip joints in > 80...

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.

A Two-Stage Foot Repair in a 55-Year-Old Man with Poliomyelitis.

Science.gov (United States)

Pollack, Daniel

2018-01-01

A 55-year-old man with poliomyelitis presented with a plantarflexed foot and painful ulceration of the sub-first metatarsophalangeal joint present for many years. A two-stage procedure was performed to bring the foot to 90°, perpendicular to the leg, and resolve the ulceration. The first stage corrected only soft-tissue components. It involved using a hydrosurgery system to debride and prepare the ulcer, a unilobed rotational skin plasty to close the ulcer, and a tendo Achillis lengthening to decrease forefoot pressure. The second stage corrected the osseous deformity with a dorsiflexory wedge osteotomy of the first metatarsal. The ulceration has remained closed since the procedures, with complete resolution of pain.

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)

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

Extraction of impacted mandibular third molars - the effect of osteotomy at two speeds on peripheral bone: a histopathological analysis.

Science.gov (United States)

Siroraj, A Pearlcid; Giri G V V; Ramkumar, Subramaniam; Narasimhan, Malathi

2016-05-01

The aim of this study was to find out the ideal speed for making a precise osteotomy with minimal damage to the surrounding bone. Thirty-six patients were divided into two groups (n=18 in each) depending on the speed of the handpiece used for osteotomy (slow=20000rpm and fast=40000rpm). Samples were taken from the peripheral bone and examined histologically to measure the margins of the osteotomy, the amount of debris produced, and the degree of thermal osteonecrosis. The osteotomy made with the high speed handpiece was better than that made with the low speed one on all counts. The margins in the high speed group were more or less precisely as required, with less debris and no thermal necrosis, which illustrated the efficacy of a high speed osteotomy. These findings can apply to other procedures that involve osteotomies in maxillofacial surgery. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Clinical and radiological outcome after periacetabular osteotomy

DEFF Research Database (Denmark)

Dahl, Line B; Dengsø, Kristine; Bang-Christiansen, Karl

2014-01-01

PURPOSE: Few papers have described results after periacetabular osteotomy (PAO) and risk factors for conversion to total hip arthroplasty (THA). The aim of the present paper was to analyse clinical and radiographic outcome, survival of the hip joint and risk factors of early conversion to THA in ...

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.

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.

Minimally Invasive Calcaneal Displacement Osteotomy Site Using a Reference Kirschner Wire: A Technique Tip.

Science.gov (United States)

Lee, Moses; Guyton, Gregory P; Zahoor, Talal; Schon, Lew C

2016-01-01

As a standard open approach, the lateral oblique incision has been widely used for calcaneal displacement osteotomy. However, just as with other orthopedic procedures that use an open approach, complications, including wound healing problems and neurovascular injury in the heel, have been reported. To help avoid these limitations, a percutaneous technique using a Shannon burr for calcaneal displacement osteotomy was introduced. However, relying on a free-hand technique without direct visualization at the osteotomy site has been a major obstacle for this technique. To address this problem, we developed a technical tip using a reference Kirschner wire. A reference Kirschner wire technique provides a reliable and accurate guide for minimally invasive calcaneal displacement osteotomy. Also, the technique should be easy to learn for surgeons new to the procedure. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Intra-articular osteotomy for distal humerus malunion

NARCIS (Netherlands)

Marti, René K.; Doornberg, Job

2009-01-01

Intra-articular osteotomy is considered in the rare case of malunion after a fracture of the distal humerus to restore humeral alignment and gain a functional arc of elbow motion. Traumatic and iatrogenic disruption of the limited blood flow to the distal end of the humerus resulting in avascular

Walking pattern in 9 women with hip dysplasia 18 months after periacetabular osteotomy

DEFF Research Database (Denmark)

Pedersen, Eva N G; Alkjaer, Tine; Søballe, Kjeld

2006-01-01

. METHODS: The gait pattern of 9 women (median age 39 years) with hip dysplasia who were treated with unilateral periacetabular osteotomy was analyzed before periacetabular osteotomy and an average of 1.5 years afterwards. Data were collected using 5 video cameras and 2 force plates. An inverse dynamics...... upright walking pattern but continued to relieve the hip joint by maintaining a reduced flexor moment....

Achievability of 3D planned bimaxillary osteotomies: maxilla-first versus mandible-first surgery

OpenAIRE

Liebregts, Jeroen; Baan, Frank; de Koning, Martien; Ongkosuwito, Edwin; Berg?, Stefaan; Maal, Thomas; Xi, Tong

2017-01-01

The present study was aimed to investigate the effects of sequencing a two-component surgical procedure for correcting malpositioned jaws (bimaxillary osteotomies); specifically, surgical repositioning of the upper jaw?maxilla, and the lower jaw?mandible. Within a population of 116 patients requiring bimaxillary osteotomies, the investigators analyzed whether there were statistically significant differences in postoperative outcome as measured by concordance with a preoperative digital 3D vir...

Case report - curved femoral osteotomy for management of medial patellar luxation

DEFF Research Database (Denmark)

Allpass, Maja; Miles, James Edward

2015-01-01

Medial patellaluxation kan forårsages af femoral varus hos hund. Førhen har patienter med excessiv femoralvarus været korrigeret ved en lateralt placeret femoral kile-ostektomi. Her præsenteres en case, hvor en buet osteotomi blev anvendt til behandling af medial patellaluxation.......Medial patellaluxation kan forårsages af femoral varus hos hund. Førhen har patienter med excessiv femoralvarus været korrigeret ved en lateralt placeret femoral kile-ostektomi. Her præsenteres en case, hvor en buet osteotomi blev anvendt til behandling af medial patellaluxation....

Piezosurgical osteotomy for harvesting intraoral block bone graft

Science.gov (United States)

Lakshmiganthan, Mahalingam; Gokulanathan, Subramanium; Shanmugasundaram, Natarajan; Daniel, Rajkumar; Ramesh, Sadashiva B.

2012-01-01

The use of ultrasonic vibrations for the cutting of bone was first introduced two decades ago. Piezoelectric surgery is a minimally invasive technique that lessens the risk of damage to surrounding soft tissues and important structures such as nerves, vessels, and mucosa. It also reduces damage to osteocytes and permits good survival of bony cells during harvesting of bone. Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implants sites. The piezosurgery system creates an effective osteotomy with minimal or no trauma to soft tissue in contrast to conventional surgical burs or saws and minimizes a patient's psychological stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device. PMID:23066242

Piezosurgical osteotomy for harvesting intraoral block bone graft

Directory of Open Access Journals (Sweden)

Mahalingam Lakshmiganthan

2012-01-01

Full Text Available The use of ultrasonic vibrations for the cutting of bone was first introduced two decades ago. Piezoelectric surgery is a minimally invasive technique that lessens the risk of damage to surrounding soft tissues and important structures such as nerves, vessels, and mucosa. It also reduces damage to osteocytes and permits good survival of bony cells during harvesting of bone. Grafting with intraoral bone blocks is a good way to reconstruct severe horizontal and vertical bone resorption in future implants sites. The piezosurgery system creates an effective osteotomy with minimal or no trauma to soft tissue in contrast to conventional surgical burs or saws and minimizes a patient′s psychological stress and fear during osteotomy under local anesthesia. The purpose of this article is to describe the harvesting of intraoral bone blocks using the piezoelectric surgery device.

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)

Neurosensory changes of palatal mucousa following Le Fort I osteotomy

Directory of Open Access Journals (Sweden)

Bijan Movahedian Attar

2009-09-01

Full Text Available

• BACKGROUND: This study evaluated the sensation of palatal ucosa before and after Le Fort I osteotomy and compared it based on whether greater palatine nerve has been dissected or not.
• METHODS: Sixteen patients were studied within one week before  urgery and then one week, 6 weeks, 3 months and 6 months after surgery. Four tests including sharp-blunt discrimination, cold perception, pin prick sensation and electrical stimulation were performed.
• RESULTS: Mean values of electrical stimulation were significantly higher 6 months after surgery (p < 0.05, on the other hand mean values of pin-prick sensation were significantly lower (p < 0.05. All patients regardless of the condition of greater palatine nerve were responsive to cold perception and sharp-blunt discrimination 6 months after surgery.
• CONCLUSIONS: Following Le Fort I osteotomy, palatal  esponsiveness to electrical stimulation decreases and mechanical hyper sensitization occurs. Dissection of greater palatine nerve was shown to have no effect on the results.
• KEYWORDS: Lefort I Osteotomy, Palatal Mocousa, Nerve Recovery.

The role of trochanteric flip osteotomy in fixation of certain acetabular fractures.

Science.gov (United States)

Gupta, Sandeep; Singh, Jagdeep; Virk, Jagandeep Singh

2017-06-01

Complete visualization of certain acetabular fractures of posterior wall or column with cranial extension involving superior dome from standard surgical exposures is a challenge. Osteotomy of the greater trochanter has been used to enhance fracture visualization, especially the dome, in posterior and lateral exposures of the acetabulum. It also decreases the need for excessive muscle retraction. The purpose of the study was to investigate the outcome associated with trochanteric flip osteotomy in the management of certain acetabulum fractures. From January 2011 to December 2013, 25 displaced acetabular fractures were treated by open reduction and internal fixation. The fractures were managed using a Kocher-Langenbeck approach along with trochanteric flip osteotomy. At 3rd, 6th and 24th month follow-up, all patients had radiographic examination and underwent a final clinical evaluation based on the modified Merle d'Aubigne and Postel score. The strength of the abductors was assessed according to the Medical Research Council (MRC) grading system. Congruent reduction was achieved in all patients and all osteotomies healed within an average period of 3.8 months. All our patients were allowed full weight bearing at the end of 3 months and with no abductor lurch at the end of 6 months follow-up. There were no cases of avascular necrosis of femoral head. None of the patients had any neurovascular complication or infection by the end of the follow-up period. Trochanteric flip osteotomy is a very effective technique to fix certain acetabular fractures especially those with dome involvement. It is more accurate and associated with no significant complications compared with conventional way. Copyright © 2017 Daping Hospital and the Research Institute of Surgery of the Third Military Medical University. Production and hosting by Elsevier B.V. All rights reserved.

[Austin's horizontal V-shaped sliding osteotomy of the metatarsal head [Chevron-osteotomy) in the treatment of hallux valgus].

Science.gov (United States)

Steinböck, G

1996-08-01

From 1983 to 1995, 1587 patients suffering from hallux abductovalgus were treated with the Austin bunionectomy. The operation consists of a medial exostosis removal, a V-shaped laterally directed displacement osteotomy of the metatarsal head, lateral release and medial reefing of the capsulo-ligamentous structures. Lateral transposition is facilitated by performing a sufficient lateral release consisting of dissection of the lateral metatarsophalangeal ligament and separation of the adductor tendon from the base of the phalanx and the lateral sesamoid. In the case of intermetatarsal angles greater than 15 degrees, the metatarsal-sesamoid ligament is also severed just above the lateral sesamoid. The periosteum is stripped in a limited fashion dorsally and toward the plantar, leaving its insertion at the metatarsal head intact. After this procedure, reposition of the metatarsal head onto the sesamoids is usually possible and is maintained by reconstruction of the medial metatarsal-sesamoid ligament. In the author's own research material, metatarsophalangeal angles larger than 50 degrees and intermetatarsal angles of over 20 degrees could be corrected. Pronation of the toe is usually corrected by tenotomy of the abductor tendon near the base of the phalanx. Avascular necrosis is extremely rare with a careful operative technique. In our extensive research material, four cases of AVN were recognized. Provided there is free motion of the joint (60-0-20), mild radiological signs of osteoarthritis are no contraindication for the operation. Even in the aged, good results can be achieved provided there are no trophic problems. The Austin bunionectomy has proved to be a versatile method for treating bunion problems. The possibility of transposing the metatarsal head laterally, toward the plantar, proximally and distally by altering the direction of the osteotomy, as well as tilting it medially or laterally, has made this osteotomy an invaluable tool for addressing various

Will immediate postoperative imbalance improve in patients with thoracolumbar/lumbar degenerative kyphoscoliosis? A comparison between Smith-Petersen osteotomy and pedicle subtraction osteotomy with an average 4 years of follow-up.

Science.gov (United States)

Bao, Hongda; He, Shouyu; Liu, Zhen; Zhu, Zezhang; Qiu, Yong; Zhu, Feng

2015-03-01

A retrospective radiographical study. To compare compensatory behavior of coronal and sagittal alignment after pedicle subtraction osteotomy (PSO) and Smith-Petersen osteotomy (SPO) for degenerative kyphoscoliosis. There was a paucity of literature paying attention to the postoperative imbalance after PSO or SPO and natural evolution of the imbalance. A retrospective study was performed on 68 consecutive patients with degenerative kyphoscoliosis treated by lumbar PSO (25 patients) or SPO (43 patients) procedures at a single institution. Long-cassette standing radiographs were taken preoperatively, postoperatively, and at the last follow-up and radiographical parameters were measured. The lower instrumented vertebral level and level of osteotomy were compared between the patients with and without improvement. Negative sagittal vertical axis (SVA) was observed in the PSO group postoperatively, implying an overcorrection of SVA. This negative SVA improved spontaneously during follow-up (P imbalance (P = 0.027), whereas no difference in term of levels of osteotomy was found (P > 0.05). The overcorrection of SVA is more often seen in the PSO group. The coronal imbalance is more likely to occur in the SPO group. The postoperative sagittal imbalance often spontaneously improves with time. Lower instrumented vertebra at S1 or with pelvic fixation should be regarded as potential risk factors for persistent coronal imbalance in patients with SPO. 3.

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

The Tax Wedge in Slovenia: International Comparison and Policy Recommendations

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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.

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.)

Effects of mandibular setback with or without maxillary advancement osteotomies on pharyngeal airways: An overview of systematic reviews.

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Su Keng Tan

Full Text Available Mandibular setback osteotomies potentially lead to narrowing of the pharyngeal airways, subsequently resulting in post-surgical obstructive sleep apnea (OSA.To summarize current evidence from systematic reviews that has evaluated pharyngeal airway changes after mandibular setback with or without concomitant upper jaw osteotomies.PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched with no restriction of language or date. Systematic reviews studying changes in pharyngeal airway dimensions and respiratory parameters after mandibular setback with or without concomitant upper jaw osteotomies have been identified, screened for eligibility, included and analyzed in this study.Six systematic reviews have been included. While isolated mandibular setback osteotomies result in reduced oropharyngeal airway dimensions, the reduction is lesser in cases with concomitant upper jaw osteotomies. Only scarce evidence exists currently to what happens to naso- and hypo-pharyngeal airways. There is no evidence for post-surgical OSA, even though some studies reported reduced respiratory parameters after single-jaw mandibular setback with or without concomitant upper jaw osteotomies.Although mandibular setback osteotomies reduce pharyngeal airway dimensions, evidence confirming post-surgical OSA was not found. Nevertheless, potential post-surgical OSA should be taken into serious consideration during the treatment planning of particular orthognathic cases. As moderate evidence exists that double-jaw surgeries lead to less compromised post-surgical pharyngeal airways, they should be considered as the method of choice especially in cases with severe dentoskeletal Class III deformity.PROSPERO (registration number: CRD42016046484.

Use of nickel titanium closed-coil springs to align unerupted teeth: a case report.

Science.gov (United States)

Samuels, R H; Peak, J D

1998-03-01

We describe a case in which a patient with a class II division I incisor relationship on a skeletal II base was transferred midway through a treatment that consisted of aligning the upper and lower arches with fixed appliance orthodontics in preparation for a mandibular advancement osteotomy. The lower second molars had previously been extracted; the lower third molars were left unerupted and some distance from the lower first molars. To provide a good occlusion at the end of treatment, it was decided to expose and approximate the lower third molars to the distal aspect of the lower first molars with the use of nickel titanium closed-coil springs; this was to be done before the osteotomy.

Application of computer-aided design osteotomy template for treatment of cubitus varus deformity in teenagers: a pilot study.

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Zhang, Yuan Z; Lu, Sheng; Chen, Bin; Zhao, Jian M; Liu, Rui; Pei, Guo X

2011-01-01

Treatment of cubitus varus deformity from a malunited fracture is a challenge. Anatomically accurate correction is the key to obtaining good functional outcomes after corrective osteotomy. The aim of this study was to attempt to increase the accuracy of treatment by use of 3-dimensional (3D) computer-aided design. We describe a novel method for ensuring an accurate osteotomy method in the treatment of cubitus varus deformity in teenagers by means of 3D reconstruction and reverse engineering. Between January 2006 and May 2008, 12 male and 6 female patients with cubitus varus deformities underwent scanning with spiral computed tomography (CT) preoperatively. The mean age was 15.7 years, ranging from 13 to 19 years. Three-dimensional CT image data of the affected and contralateral normal bones of cubitus were transferred to a computer workstation. Three-dimensional models of cubitus were reconstructed by use of MIMICS software. The 3D models were then processed by Imageware software. An osteotomy template that best fitted the angle and range of osteotomy was "reversely" built from the 3D model. These templates were manufactured by a rapid prototyping machine. The osteotomy templates guide the osteotomy of cubitus. An accurate angle of osteotomy was confirmed by postoperative radiography. After 12 to 24 months' follow-up, the mean postoperative carrying angle in 18 patients with cubitus varus deformity was 7.3° (range, 5° to 11°), with a mean correction of 21.9° (range, 12° to 41°). The patient-specific template technique is easy to use, can simplify the surgical act, and generates highly accurate osteotomy in cubitus varus deformity in teenagers. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Piezosurgery for Sagittal Split Osteotomy: Procedure Duration and Postoperative Sensory Perturbation.

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Köhnke, Robert; Kolk, Andreas; Kluwe, Lan; Ploder, Oliver

2017-09-01

To evaluate piezosurgery for bilateral sagittal split osteotomy (BSSO) for its duration and inferior alveolar nerve (IAN) perturbation. In this prospective randomized study, the authors evaluated 100 BSSO procedures in 50 patients. Piezoelectric (group I) and conventional (group II) osteotomies were carried out on each side of the mandible of a patient by 2 specialists. The surgeons had at least 1 year of experience using piezosurgery. The period from incision to complete splitting of the mandibular bone was recorded (ie, procedure duration). The intraoperative status (visibility and relocation) of the IAN also was recorded. The neurosensory function of the IAN was measured by the 2-point discrimination threshold and static light touch methods before surgery and postoperatively (1, 3, and 6 weeks and 6 and 12 months). Parameters were compared between the test groups by the paired t, nonparametric Wilcoxon, or χ 2 test. Intergroup comparison showed the mean duration of osteotomy was significantly shorter for group I (17 ± 6 vs 25 ± 9 minutes; P < .001). The rate of intraoperative exposures of the IAN was slightly lower for group I (68%) compared with group II (81%). However, the difference was not relevant. Neurosensory disturbance and recovery of the IAN did not differ between groups. Piezoelectric osteotomy requires considerably less time than conventional mechanical approaches, but shows no advantage in preventing neurosensory perturbation. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Shortening Scarf osteotomy for correction of severe hallux valgus. Does shortening affect the outcome?

Science.gov (United States)

Karpe, Prasad; Killen, Marie C; Pollock, Raymond D; Limaye, Rajiv

2016-12-01

Translation and shortening of Scarf osteotomy allows correction of severe hallux valgus deformity. Shortening may result in transfer metatarsalgia. To evaluate outcome of patients undergoing shortening Scarf osteotomy for severe hallux valgus deformities. Fifteen patients (20feet, mean age 58 years) underwent shortening Scarf osteotomy for severe hallux valgus deformities. Outcomes were pre and postoperative AOFAS scores, IM and HV angles, patient satisfaction. Mean follow-up was 25 months (range 22-30). The IM angle improved from a median of 18.60 (range 13.4-26.20) preoperatively to 9.70 (range 8.0-13.70) postoperatively (8.9; 95% CI=7.6-10.3; phallux valgus deformities with no transfer metatarsalgia. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The use of Piezosurgery osteotomy in treatment of long-standing maxillary fractures: report of 12 consecutive patients].

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Guo, Zhao-Zhong; Liu, Xue; Li, Yan; Deng, Yan-Fang; Wang, Yang

2007-02-01

To evaluate the clinical applicability of Piezosurgery osteotomy: a new safe technique in managing long standing maxillary fractures. 12 patients with long-standing maxillary fractures were surgically treated using Le Fort I osteotomy. During operation, Piezosurgery osteotomy was used for bone cutting and splitting. After repositioning, the bone segments were rigidly fixed with micro Ti-plate, Ti-mesh. All the patients were followed up for 6 to 12 months, and the functional and esthetic results were evaluated. Ultrasonic microvibrations allow accurate bone cutting without oscillating injuries to the soft tissue. All the wounds healed primarily without complications. The postoperative occlusion and appearance were satisfactory. Maximal recovery of mastication and appearance can be achieved by using Piezosurgery osteotomy with fixation materials such as Ti-plates and Ti-meshes in selected patients with long-standing maxillary fractures.

Brachymetatarsia of the fourth metatarsal, lengthening scarf osteotomy with bone graft.

Science.gov (United States)

Desai, Ankit; Lidder, Surjit; R Armitage, Andrew; S Rajaratnam, Samuel; D Skyrme, Andrew

2013-01-01

A 16-year-old girl presented with left fourth metatarsal shortening causing significant psychological distress. She underwent lengthening scarf osteotomy held with an Omnitech(®) screw (Biotech International, France) with the addition of two 1 cm cancellous cubes (RTI Biologics, United States). A lengthening zplasty of the extensor tendons and skin were also performed. At 6 weeks the patient was fully weight bearing and at one-year follow up, the patient was satisfied and discharged. A modified technique of lengthening scarf osteotomy is described for congenital brachymatatarsia. This technique allows one stage lengthening through a single incision with graft incorporation by 6 weeks.

Staple fixation for akin proximal phalangeal osteotomy in the treatment of hallux valgus interphalangeus.

Science.gov (United States)

Neumann, Julie A; Reay, Kathleen D; Bradley, Kendall E; Parekh, Selene G

2015-04-01

The Akin proximal phalangeal osteotomy is commonly used in conjunction with metatarsal osteotomies to treat hallux valgus. Multiple fixation methods including suture, wire, screw, and staple fixation have been described. The aims of this study were to assess the intraoperative and postoperative complications and to evaluate short-term postoperative outcomes in patients who underwent Akin osteotomy with staple fixation. Forty-four patients (51 feet) with painful hallux valgus were retrospectively reviewed at an average of 40.4 ± 15.8 (range, 25.9 to 79.9) weeks following an Akin osteotomy with staple fixation. Patient reported preoperative and postoperative Visual Analog Score (VAS) (0 to 10, 0 = no pain) was recorded. Level of activity was reported postoperatively. Hallux valgus angles (HVAs), intermetatarsal angles (IMAs), and hallux valgus interphalangeus angles (IPAs) were evaluated on preoperative as well as final postoperative radiographs. Postoperative clinical and radiographic examinations were used to evaluate for complications. Mean VAS improved from 4.4 ± 2.6 to 1.0 ± 1.2 (P hallux valgus correction with improvement in pain and hallux valgus deformity with a low risk for complications. Level IV, case series. © The Author(s) 2014.

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

Evaluation of Mandibular Anatomy Associated With Bad Splits in Sagittal Split Ramus Osteotomy of Mandible.

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Wang, Tongyue; Han, Jeong Joon; Oh, Hee-Kyun; Park, Hong-Ju; Jung, Seunggon; Park, Yeong-Joon; Kook, Min-Suk

2016-07-01

This study aimed to identify risk factors associated with bad splits during sagittal split ramus osteotomy by using three-dimensional computed tomography. This study included 8 bad splits and 47 normal patients without bad splits. Mandibular anatomic parameters related to osteotomy line were measured. These included anteroposterior width of the ramus at level of lingula, distance between external oblique ridge and lingula, distance between sigmoid notch and inferior border of mandible, mandibular angle, distance between inferior outer surface of mandibular canal and inferior border of mandible under distal root of second molar (MCEM), buccolingual thickness of the ramus at level of lingula, and buccolingual thickness of the area just distal to first molar (BTM1) and second molar (BTM2). The incidence of bad splits in 625 sagittal split osteotomies was 1.28%. Compared with normal group, bad split group exhibited significantly thinner BTM2 and shorter sigmoid notch and inferior border of mandible (P bad splits. These anatomic data may help surgeons to choose the safest surgical techniques and best osteotomy sites.

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.

Three-dimensional vertebral wedging in mild and moderate adolescent idiopathic scoliosis.

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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

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

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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

Surgical risk factors and maxillary nerve function after le fort I osteotomy

DEFF Research Database (Denmark)

Thygesen, Torben Henrik; Jensen, Allan Bardow; Norholt, SE

2009-01-01

PURPOSE: Data on intraoperative risk factors for long-term postoperative complications after Le Fort I osteotomy (LFO) are limited. The aim of this study was to describe prospectively the overall postoperative changes in maxillary nerve function after LFO, and to correlate these changes with a nu......PURPOSE: Data on intraoperative risk factors for long-term postoperative complications after Le Fort I osteotomy (LFO) are limited. The aim of this study was to describe prospectively the overall postoperative changes in maxillary nerve function after LFO, and to correlate these changes...

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

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)

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...

Effects of long-term administration of carprofen on healing of a tibial osteotomy in dogs.

Science.gov (United States)

Ochi, Hiroki; Hara, Yasushi; Asou, Yoshinori; Harada, Yasuji; Nezu, Yoshinori; Yogo, Takuya; Shinomiya, Kenichi; Tagawa, Masahiro

2011-05-01

To evaluate effects of long-term administration of carprofen on healing of a tibial osteotomy in dogs. 12 healthy female Beagles. A mid-diaphyseal transverse osteotomy (stabilized with an intramedullary pin) of the right tibia was performed in each dog. The carprofen group (n = 6 dogs) received carprofen (2.2 mg/kg, PO, q 12 h) for 120 days; the control group (6) received no treatment. Bone healing and change in callus area were assessed radiographically over time. Dogs were euthanized 120 days after surgery, and tibiae were evaluated biomechanically and histologically. The osteotomy line was not evident in the control group on radiographs obtained 120 days after surgery. In contrast, the osteotomy line was still evident in the carprofen group. Callus area was significantly less in the carprofen group, compared with the area in the control group, at 20, 30, and 60 days after surgery. At 120 days after surgery, stiffness, elastic modulus, and flexural rigidity in the carprofen group were significantly lower than corresponding values in the control group. Furthermore, histologic evaluation revealed that the cartilage area within the callus in the carprofen group was significantly greater than that in the control group. Long-term administration of carprofen appeared to inhibit bone healing in dogs that underwent tibial osteotomy. We recommend caution for carprofen administration when treating fractures that have delays in healing associated with a reduction in osteogenesis as well as fractures associated with diseases that predispose animals to delays of osseous repair.

SURGICAL TREATMENT OF MALUNITED COLLES’ FRACTURE BY CORRECTIVE OSTEOTOMY

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Gopinath

2015-12-01

Full Text Available BACKGROUND Malunion occurs more often after Colles fracture than any other and can result in considerable disability. Multiple techniques for corrective osteotomy have been developed in recent years with objective of restoring the normal anatomy of distal end of radius and also to evaluate the results with respect to pain, restoration of function of wrist and forearm. MATERIALS AND METHODS A prospective randomized controlled study was conducted in 20 cases of malunited Colles fracture who underwent Corrective osteotomy with a Dorsal Ellis T plate and bone graft. Post operatively all patients were immobilized on a Sugar-Tong splint and followed up at 4, 6 and 12 weeks. RESULTS All measurements of Pain, final range of motion and grip strength significantly improved compared with preoperative measurements. Based on Fernandez et al scoring system we obtained Excellent results in 8 cases, Good in 7 cases, Fair in 3 cases and Poor in 2 cases which was attributed to infection in 1 case and RSD in the other case. Radiologically a mean radial length of 6.14mm (N:10mm, Radial Angle of 21.25⁰ (N:22⁰ and Volar angle of -3.4⁰ (N: +4⁰ was achieved. CONCLUSION Corrective Osteotomy with Bone graft is a preferred and an Ideal procedure if performed after Proper selection of patients i.e in young adults and extra articular malunions with good range of movements.

Triple pelvic osteotomy: effect on limb function and progression of degenerative joint disease

International Nuclear Information System (INIS)

Johnson, A.L.; Smith, C.W.; Pijanowski, G.J.; Hungerford, L.L.

1998-01-01

The objective of this study was to evaluate prospectively the outcome of 21 clinical patients treated with triple pelvic osteotomies during the year following surgery. Specific aims included documenting the time of and extent of improved limb function as measured by force plate analysis, evaluating the progression of degenerative joint disease (DJD) in the treated and untreated coxofemoral joints, and determining whether or not triple pelvic osteotomy resulted in degenerative joint changes in the ipsilateral stifle and hock. Twelve dogs were treated unilaterally and nine dogs were treated bilaterally with triple pelvic osteotomies. There were no differences in mean anteversion angles, angles of inclination, or preoperative DJD between treated hips and untreated hips. Degenerative joint disease progressed significantly in all hips regardless of treatment. Two cases developed hyperextension of their hocks after the triple pelvic osteotomies. However, no radiographic evidence of DJD was observed for any of the stifles or hocks at any observation time. A significant increase in vertical peak force (VPF) scores was noted for treated legs by two-to-three months after surgery, which continued over time. Untreated legs did not show a significant change in VPF scores over time. No differences were found in progression to higher scores when unilaterally treated legs, first-side treated legs, and second-side treated legs were compared

Brachymetatarsia of the fourth metatarsal, lengthening scarf osteotomy with bone graft

Directory of Open Access Journals (Sweden)

Ankit Desai

2013-09-01

Full Text Available A 16-year-old girl presented with left fourth metatarsal shortening causing significant psychological distress. She underwent lengthening scarf osteotomy held with an Omnitech® screw (Biotech International, France with the addition of two 1 cm cancellous cubes (RTI Biologics, United States. A lengthening z-plasty of the extensor tendons and skin were also performed. At 6 weeks the patient was fully weight bearing and at one-year follow up, the patient was satisfied and discharged. A modified technique of lengthening scarf osteotomy is described for congenital brachymatatarsia. This technique allows one stage lengthening through a single incision with graft incorporation by 6 weeks.

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.

Triple pelvic osteotomy in Legg-Calve-Perthes disease using a single anterolateral incision: a 4-year review.

LENUS (Irish Health Repository)

Conroy, Eimear

2010-07-01

Femoral head incongruency at skeletal maturity is associated with the development of osteoarthritis in early adulthood. Containment of the femoral head provides a larger surface area for remodelling of the collapsed femoral head and the development of spherical congruency. Triple pelvic osteotomy has a role to play in Legg-Calve-Perthes\\' disease by improving femoral head containment and preventing subluxation. This is traditionally a two-incision approach with significant associated morbidity. In our unit we perform triple osteotomies through a single anterolateral incision. To retrospectively review the clinical and radiographic outcome of children who had triple osteotomies performed through a single incision over a 4-year period. In our unit from 2003 to 2006 we performed eight triple osteotomies through a single incision in children aged between 6 and 12 years with Legg-Calve-Perthes\\' disease. The procedure was performed through a single anterolateral incision made beneath the middle of the iliac crest and carried forward according to Salter\\'s osteotomy. Image intensification was used to confirm iliac, pubic and ischial cuts. After performing a standard Salter\\'s osteotomy the acetabular fragment was free to rotate anteriorly and laterally. None of the children were casted and all were allowed immediate mobilization nonweight bearing with crutches for 6 weeks. Clinical results and hip function were measured preoperatively and postoperatively using the modified Harris hip score. The average length of hospital stay was 4.7 days. None of the children had a nonunion. The centre edge angle of Wiberg was measured on all preoperative and postoperative anteroposterior pelvic radiographs. In all our patients there was an improvement in the centre edge angle of Wiberg and in the modified Harris hip score. The preoperative modified Harris hip scores ranged from 38 to 60 and postoperatively ranged from 77 to 92. The preoperative centre edge angle of Wiberg ranged

[How to make your own custom cutting guides for both mandibular and fibular stair step osteotomies?

Science.gov (United States)

Rem, K; Bosc, R; De Kermadec, H; Hersant, B; Meningaud, J-P

2017-12-01

Using tailored cutting guides for osteocutaneous free fibula flap in complex mandibular reconstruction after cancer resection surgery constitutes a substantial improvement. Autonomously conceiving and manufacturing the cutting guides within a plastic surgery department with computer-aided design (CAD) and three-dimensional (3D) printing allows planning more complex osteotomies, such as stair-step osteotomies, in order to achieve more stable internal fixations. For the past three years, we have been producing by ourselves patient-tailored cutting guides using CAD and 3D printing. Osteotomies were virtually planned, making the cutting lines more complex in order to optimize the internal fixation stability. We also printed reconstructed mandible templates and shaped the reconstruction plates on them. We recorded data including manufacturing techniques and surgical outcomes. Eleven consecutive patients were operated on for an oral cavity cancer. For each patient, we planned the fibular and mandibular stair-step osteotomies and we produced tailored cutting guides. In all patients, we achieved to get immediately stable internal fixations and in 10 patients, a complete bone consolidation after 6 months. Autonomously manufacturing surgical cutting guides for mandibular reconstruction by free fibula flap is a significant improvement, regarding ergonomics and precision. Planning stair-step osteotomies to perform complementary internal fixation increases contact surface and congruence between the bone segments, thus improving the reconstructed mandible stability. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Midterm outcome after correction of hallux valgus deformity using scarf osteotomy in adult population

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Laura Ibrahim Alolayan

2017-01-01

Full Text Available Context: Determining the efficacy of any surgical treatment is the key to achieve better practice and best outcomes for patients. Aims: This study is designed to address midterm outcome in adult patients with moderate-to-severe hallux valgus (HV, who underwent scarf osteotomy from 2012 to 2014. Settings and Design: This is a retrospective cohort study in which charts of all adult patients with moderate-to-severe HV who underwent scarf osteotomy from 2011 to 2014 were reviewed. Subjects and Methods: Between 2011 and 2014, 39 patients (41 feet who underwent scarf osteotomy for correction of HV deformity were retrospectively evaluated. Standard weight-bearing dorsoplantar radiographs were obtained pre- and postoperatively. HV angle (HVA, intermetatarsal angle (IMA and distal metatarsal articular angles (DMAA were measured pre- and postoperatively to evaluate the efficacy of the surgery. The complication rate was reported. The average follow-up was 13.5 months, and the patients' mean age was 37 years. Statistical Analysis Used: Data were compared using Chi-square test or Fisher's exact test whichever was appropriate. All tests were two-sided, and a P> 0.01 was considered statistically significant. Results: The average preoperative HVA and IMA were 32° and 14.3°, which improved to 11° and 7.9°, respectively. The changes were statistically significant (P 0.18. Conclusions: This study suggests that scarf osteotomy surgery is a very versatile osteotomy in correcting moderate-to-severe HV deformity. It offers a greater degree of correction and stability, lower rate of complications and good outcome. However, long-term follow-up studies are still needed.

No midterm benefit from low intensity pulsed ultrasound after chevron osteotomy for hallux valgus.

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Zacherl, Max; Gruber, Gerald; Radl, Roman; Rehak, Peter H; Windhager, Reinhard

2009-08-01

Chevron osteotomy is a widely accepted method for correction of symptomatic hallux valgus deformity. Full weight bearing in regular shoes is not recommended before 6 weeks after surgery. Low intensity pulsed ultrasound is known to stimulate bone formation leading to more stable callus and faster bony fusion. We performed a randomized, placebo-controlled, double-blinded study on 44 participants (52 feet) who underwent chevron osteotomy to evaluate the influence of daily transcutaneous low intensity pulsed ultrasound (LIPUS) treatment at the site of osteotomy. Follow-up at 6 weeks and 1 year included plain dorsoplantar radiographs, hallux-metatarsophalangeal-interphalangeal scale and a questionnaire on patient satisfaction. There was no statistical difference in any pre- or postoperative clinical features, patient satisfaction or radiographic measurements (hallux valgus angle, intermetatarsal angle, sesamoid index and metatarsal index) except for the first distal metatarsal articular angle (DMAA). The DMAA showed statistically significant (p = 0.046) relapse in the placebo group upon comparison of intraoperative radiographs after correction and fixation (5.2 degrees) and at the 6-week follow-up (10.6 degrees). Despite potential impact of LIPUS on bone formation, we found no evidence of an influence on outcome 6 weeks and 1 year after chevron osteotomy for correction of hallux valgus deformity.

Ratio of lumbar 3-column osteotomy closure: patient-specific deformity characteristics and level of resection impact correction of truncal versus pelvic compensation.

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Diebo, Bassel G; Lafage, Renaud; Ames, Christopher P; Bess, Shay; Obeid, Ibrahim; Klineberg, Eric; Cunningham, Matthew E; Smith, Justin S; Hostin, Richard; Liu, Shian; Passias, Peter G; Schwab, Frank J; Lafage, Virginie

2016-08-01

The resection point of a lumbar three-column osteotomy (3CO) creates separation of the spino-pelvic complex. This study investigates the impact of patients' baseline deformity and level of 3CO resection on the distribution of correction between the trunk and the pelvis following osteotomy closure. Patients who underwent single lumbar 3CO, upper instrumented vertebra (UIV) T1-T10, and 6 month follow-up were included. The truncal and pelvic closures were calculated based on the vertebrae adjacent to the osteotomy level and the impact of radiographic parameters and level of 3CO on the closures were analyzed. 113 patients were included. Patients who experienced more pelvic correction had significantly higher Pelvic Tilt and lower Sagittal Vertical Axis at baseline. Patients who underwent more caudal osteotomies with higher pelvic compensation with modest SVA sustained more pelvic correction. The osteotomy closure is driven by patient's specific deformity. More caudal osteotomy level leads to greater pelvic tilt improvement. III.

Mini-Invasive floating metatarsal osteotomy for resistant or recurrent neuropathic plantar metatarsal head ulcers

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Tamir, Eran; Finestone, Aharon S.; Avisar, Erez; Agar, Gabriel

2016-01-01

Background Patients with peripheral neuropathy and pressure under a relatively plantar deviated metatarsal head frequently develop plantar foot ulcers. When conservative management with orthotics and shoes does not cure the ulcer, surgical metatarsal osteotomy may be indicated to relieve the pressure and enable the ulcer to heal. The purpose of this study is to evaluate the use of a mini-invasive floating metatarsal osteotomy in treating recalcitrant ulcers or recurrent ulcers plantar to the ...

A minimally invasive technique using a modified stoppa approach for periacetabular osteotomy: A preliminary cadaveric study

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Turgut Akgul

2017-01-01

Full Text Available Background: Developmental hip dysplasia is diagnosed when the femoral head is not sufficiently covered by the acetabulum. Anterior and lateral cover deficiency is seen, as a result a dysplastic hip joint. Various incision modifications have been developed because of the muscle dissection and wide wound scar in Smith-Peterson incision, which was originally used in Bernese osteotomy. This study evaluates applicability of the modified Stoppa approach in the performance of Bernese periacetabular osteotomy (PAO. Materials and Methods: Ten hemipelvises of five donor cadavers were used. The transverse Stoppa incision was made 2 cm over the symphysis pubis for quadrilateral surface exposure and pubic and ischial bone osteotomies. The second skin incision, a few centimeters lateral to the original incision, was made along the tensor fascia lata. Iliac bone osteotomy was performed starting just above the rectus femoris insertion. The displacement of the osteotomy was measured clinically and radiographically. Results: The mean anterior coverage calculated with center-edge angle was improved from 22.8° ±2.8 (range 20° min–28° max preoperatively to 44.1° ± 3.7 (range 36° min–48° max. The displacement of the osteotomy at the iliopectineal line calculated on the iliac inlet view radiographs was 22.1 ± 3.4 mm (range 15 mm min–26 mm max. The clinical amount of the anterior displacement on the cadavers was 17.8 ± 3.35 mm (range 11 mm–21 mm and lateral displacement was 20.3 ± 3.23 mm (range 15 mm–24 mm. The amount of the posterior intact bone enlargement at the quadrilateral surface was 5.3 ± 0.48 mm. Conclusion: This less traumatic two-incision exposure is an adequate technique for Bernese PAO, allowing the bone to be cut under direct visual observation and reducing the need to use fluoroscopy.

Multiple phases and vicious walkers in a wedge

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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.

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...

The early functional outcome of Mau osteotomy for the correction of moderate-severe hallux valgus

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Tanujan Thangarajah

2013-11-01

Full Text Available Hallux valgus is one of the commonest conditions of the foot and has been reported to affect nearly half of the adult population. It is most effectively treated by a corrective osteotomy of which there a numerous subtypes. The Mau osteotomy confers the greatest structural stability but is not thought to provide adequate correction of moderate-severe deformities. Accordingly, complications such as under correction and non-union are common. The aim of this study was to determine the functional outcome in patients with moderate-severe hallux valgus following a Mau osteotomy. A retrospective review of 23 patients with moderate-severe hallux valgus treated by Mau osteotomy was conducted. Patients were assessed clinically by the American Orthopedic Foot and Ankle Society (AOFAS scoring system and radiologically by measuring the first intermetatarsal (IM and hallux abductovalgus angles (HAV. The mean AOFAS score had improved from 47 preoperatively to 92 postoperatively (P<0.01. Additionally, preoperative HAV and IM angles improved from 39° and 15° respectively to 15° and 9° respectively (P<0.01. There were no cases of undercorrection or non-union. In this series, the Mau osteotomy was able to achieve good correction of the IM and HAV angles in patients with moderate-severe hallux valgus. This was reflected in a significantly higher postoperative AOFAS score. Contrary to other studies there were no cases of undercorrection and despite allowing patients to fully weight-bear postoperatively there were no cases of non-union.

Pedicle subtraction osteotomy in elderly patients with degenerative sagittal imbalance.

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Cho, Kyu-Jung; Kim, Ki-Tack; Kim, Whoan-Jeang; Lee, Sang-Hoon; Jung, Jae-Hoon; Kim, Young-Tae; Park, Hae-Bong

2013-11-15

Retrospective, radiographical analysis. To evaluate pedicle subtraction osteotomy (PSO) as a means of correcting severe degenerative sagittal imbalance in elderly patients. PSO in patients with degenerative sagittal imbalance is likely to cause more complications than in patients with iatrogenic flatback deformity. This study analyzed 34 patients who underwent fusion to the sacrum, with a minimum 2-year follow-up. Age of the patients were in the range from 58 to 73 with the mean at 65.5 years. PSO was performed at one segment in all cases, consisting of L3 (n = 26), L4 (n = 4), L2 (n = 3), and L1 (n = 1). The average number of levels fused was 8.15. Ten patients had structural interbody fusion at the lumbosacral junction. Applying PSO at one segment, the mean correction of the lordotic angle at the osteotomy site was 33.3°, of which the loss of correction (LOC) was 4.0° at the last visit. The correction of lumbar lordosis was 33.7° and the LOC was 8.5°. The sagittal C7 plumb was 215.9 mm before surgery, corrected to 35.1 mm after surgery, and changed to 95.9 mm by the last visit. The correction of the sagittal C7 plumb was 119.9 mm and the LOC was 60.9 mm. There was substantial LOC in lumbar lordosis and sagittal C7 plumb. In 10 patients with addition of posterior lumbar interbody fusion, the LOC of lumbar lordosis was 7.4°, which was less than 9° in those without it. PSO for the correction of degenerative sagittal imbalance in elderly patients resulted in correction of sagittal alignment with a significant LOC of lumbar lordosis and sagittal C7 plumb. The LOC of lumbar lordosis occurred at both the osteotomy and non-osteotomy site. The addition of anterior column support is helpful to maintain correction and reduce complications. N/A.

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)

Modified Wilson’s Osteotomy for Hallux Valgus Deformity. A New Approach

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Xarchas, Konstantinos C; Mavrolias, Dimitrios; Kyriakopoulos, Georgios

2014-01-01

We introduce a new set of modifications and present the results from 48 patients (a total of 60 feet operated), who underwent this modified Wilson’s osteotomy for the correction of Hallux Valgus. Patients were of an average age of 52 years old (from 21 to 75 years of age) and were followed up for a mean of 12 months post-operatively. Patient evaluation was made with the symptom scoring system as presented by Kataraglis et al., with the final outcome being satisfactory in all of the cases. This set of modifications introduced to the original Wilson’s osteotomy, proved to offer a stable, predictable and satisfactory outcome in all cases and we strongly recommend it. PMID:25352929

Total knee replacement with tibial tubercle osteotomy in rheumatoid patients with stiff knee.

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Eid, Ahmed Salem; Nassar, Wael Ahmed Mohamed; Fayyad, Tamer Abdelmeguid Mohamed

2016-11-01

Total knee arthroplasty (TKA) is a well-proven modality that can provide pain relief and restore mobility for rheumatoid arthritis (RA) patients with advanced joint destruction. Patellar ligament avulsion, especially in presence of poor bone quality and knee stiffness, is one of the special considerations that must be addressed in this unique population of patients. This study aimed to determine the functional results in a series of rheumatoid patients with stiff knee and end-stage joint destruction who underwent tibial tubercle osteotomy during TKA. Twenty-three knees in 20 patients (16 women; four men) at a mean age of 54 years with end-stage arthritis and knee stiffness due to RA were operated upon for TKA using tibial tubercle osteotomy as a step during the operation. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Hospital for Special Surgery (HSS) score was recorded pre-operatively and at six and 12 months postoperatively. Union occurred at the osteotomy site in 21 of 23 cases. One case had deep venous thrombosis (DVT). There was no infection or periprosthetic fracture, and at last follow-up, no patient required revision. HSS score improved from 46 (15-60) pre-operatively to 85 (71-96) post-operatively. Tibial tubercle osteotomy during TKA in patients with RA and stiff knee is technically demanding yet proved to be effective in improving post-operative range of movement and minimising the complication of patellar ligament avulsion.

A modified Austin/chevron osteotomy for treatment of hallux valgus and hallux rigidus.

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Vasso, Michele; Del Regno, Chiara; D'Amelio, Antonio; Schiavone Panni, Alfredo

2016-03-01

The purpose of this brief paper is to present the preliminary results of a modified Austin/chevron osteotomy for treatment of hallux valgus and hallux rigidus. In this procedure, the dorsal arm of the osteotomy is performed orthogonal to the horizontal plane of the first metatarsal, the main advantage being that this allows much easier and more accurate multiplanar correction of first metatarsal deformities. From 2010 to 2013, 184 consecutive patients with symptomatic hallux valgus and 48 patients with hallux rigidus without severe metatarsophalangeal joint degeneration underwent such modified chevron osteotomy. Mean patient age was 54.9 (range 21-70) years, and mean follow-up duration was 41.7 (range 24-56) months. Ninety-three percent of patients were satisfied with the surgery. Mean American Orthopaedic Foot and Ankle Society (AOFAS) score improved from 56.6 preoperatively to 90.6 at last follow-up, and mean visual analog scale (VAS) pain score decreased from 5.7 preoperatively to 1.6 at final follow-up (p hallux valgus, mean hallux valgus angle decreased from 34.1° preoperatively to 6.2° at final follow-up, and mean intermetatarsal angle decreased from 18.5° preoperatively to 4.1° at final follow-up (p < 0.05). One patient developed postoperative transfer metatarsalgia, treated successfully with second-time percutaneous osteotomy of the minor metatarsals, whilst one patient had wound infection that resolved with systemic antibiotics. Level IV.

Salter%u2019s Innominate Osteotomy in the Treatment of Congenital Hip Dislocation

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Eyup Cagatay Zengin

2014-03-01

Full Text Available Aim: Developmental displazy of hip is much seenillness which interest orthopaedic surgery in Turkey and around the world. In early times of illness conservative treatment is succesful but late times of illness surgery is necessary. Salter’s innominate osteotomy, since its initial description in 1961, has become a well-established surgical procedure in the treatment of congenital dislocation of the hip.Material and Method: We reviewed 59 patients with 74 congenitally dislocated hips, all managed by open reduction and Salter’s innominate osteotomy. Mean follow-up period was 4,2 years (range, 2 to 7 years; %82,4 of the hips had a excellent clinical result, and %75,7 were excellent radiologically. The patients who underwent Salter’s innominate osteotomy before the age of 3 had beter clinical and radiological results (%90,4 and %82,5, respectively. The radiographs of the unilateral normal hips were compared to the surgically treated hips according to their acetabular index angles, center-edge angles of Wiberg and femoral neck-shaft angles. No statistical differences were found between these two groups. The Kalamchi-McEwen classification of avascular necrosis. The late radiographic signs of types 2, 3 and 4 avasculer necrosis were seen in %10,8 of this series. Discussion: The results show that Salter’s innominate osteotomy provides good lateral coverage of the femoral head. The results are beter if the operation is performed between the ages 18 months and 3 years.

Hallux valgus with Scarf Osteotomy - A revision of 82 cases

International Nuclear Information System (INIS)

Mendez Gonzalez, Mauricio; Gamba Sanchez, Carlos Enrique

2005-01-01

Descriptive observational study, type series of cases, whose objective was to describe the treatment of hallux valgus with Scarf Osteotomy; this study reviewed the clinical, radiological and subjective aspects of 82 feet, mean age of 49 years, and a mean of 14 degrades and 31 degrades to 9 degrades and 14 degrades (p<0,0001). The mean of the AOFAS scale improved from 49 points preoperatively to 92 points (p<0,0001). 61% of the patients were very satisfied, 34% were satisfied and 5% were not satisfied with the procedure. The recurrence of the deformity appeared in 3% of the patients. The rate of complications was of 6%. The SCARF osteotomy is a safe procedure. We recommended it like an effective technique for the correction of hallux valgus mild, moderate and severe

Outcome of one stage combined open reduction, pelvic and derotation femoral osteotomy in congenital dislocated hips of children younger than three years age

International Nuclear Information System (INIS)

Bhatti, A.; Kumar, J.; Butt, S. A.

2014-01-01

Objective: To determine the outcome of one-stage combined operative management of congenital dislocation of hips in children aged 18-36 months. Methods: The descriptive case series study was conducted at the Department of Orthopaedic Surgery, Jinnah Postgraduate Medical Centre, Karachi, from January 2005 to December 2011. Children aged 18-36 months suffering from congenital dislocation of hips were included. Those with Tonnis stage III and IV were managed with one-stage operative procedure without preliminary traction. The operative procedure included adductor tenotomy, open reduction, capsulorraphy, Salter's osteotomy and a femoral derotation osteotomy. Catteral's 'Test of Stability' was used after open reduction as an indicator for need of pelvic and femoral osteotomies. Follow-up ranged between 1 and 7 years. The patients were evaluated clinically on McKay's criteria and radiologically on Severin's criteria. Klisic's overall rating was used to know mean of the assessments. Results: There were 38 patients with 50 congenital dislocations of hip. There were 26(68.42%) females and 12(31.57%) males with a female-to-male ratio of 2:1. Mean age at the time of operation was 24.26+-7.6 months. Of the total, 12(31.57%) patients had bilateral involvement, 11(28.94%) had right-sided and 15(39.47%) had left- sided involvement. Right side to Left ratio was 1:1.2. At the time of last follow-up, 25(50%) hips behaved excellent on McKay's criteria. According to radiographic classification on Severin's criteria, 24(48%) hips were in excellent class. Avascular necrosis of femoral head was noted in 3(6%) hips, re-subluxation/re-dislocations were observed in 3(6%) hips and 1(2.6%) patient had 1cm femoral lengthening. Conclusion: One-stage open reduction, capsulorrapyhy, Salter's osteotomy and femoral derotation osteotomy without preliminary traction to re-locate congenital dislocation of hips in late presenting children is a safe and highly effective method. It produces a low rate of

[Prophylactic osteotomy of pelvis in dysplastic acetabulum.].

Science.gov (United States)

Richtr, M; Sosna, A

1998-01-01

Acetabular dysplasia and anatomical changes of pelvis accompanied with gracility of iliac bone pose a problem for a reliable fixation of acetabular component. In extreme cases the bone stock is not sufficient to accommodate the smallest size of the cup. Sometimes even reaming of the bed down to lamina interna is not sufficient for an adequate covering of the implant. Consequently, weakening of the bottom of acetabulum may be not only one of the causes of the failure of the implant but it makes difficult also the following revision surgeries. Therefore in acetabular dysplasia the authors recommend acetabuloplasty of the bottom of acetabulum preserving its original thickness including inner cortex. They recommend to perform osteotomy of the full thickness of the medial wall of acetabulum and move the massive bone graft created in this way farther into pelvis. At the same time they take care to preserve blood supply of the bone graft by retaining corticoperiostal bridge by means of osteoclasia. The suggested procedure allows full coverage of the implant by iliac bone and at the same time preserves a firm support of acetabular fossa. The original thickness of the medial wall of acetabulum is considered by authors as a significant antimigration barrier. In the period 1991 -1994 the authors used this method at Ist Orthopaedic Clinic of 1st Medical Faculty, Charles University in Prague in total in 16 patients. In all of them after 6 months the bone graft was fully absorbed. Remodelling of the bone graft occurred 1 to 2 years after the surgery and after that the thickness of the graft remained the same. Neither any change of the structure nor reduction of the thickness of the graft was found between 3rd and 4th year after the surgery. The nature of trabecular remodelling of the bone graft corresponds to the transfer of forces in loading the graft by acetabular cup. Key words: acetabuloplasty, osteotomy of the medial wall of acetabulum, osteotomy of pelvis, THR, acetabular

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

Boomerang proximal tibial osteotomy for the treatment of severe varus gonarthrosis.

Science.gov (United States)

Sangkaew, Chanchit; Piyapittayanun, Peerapong

2013-06-01

The purpose of the study was to review the results of modified infratubercle displacement osteotomy in patients with severe varus gonarthrosis and to determine the factors influencing outcomes. A total of 177 knees in 133 patients with severe varus gonarthrosis were treated with infratubercle boomerang-shaped osteotomy, stabilised with dual plates. The mean age of the patients was 63.8 years (range 43-80 years), and the mean follow-up period was 61.4 months (range 24 -139 months). The factors associated with clinical and survival outcomes were analysed including age, gender, body mass index (BMI), preoperative and post-operative femorotibial angle and femorotibial angle at one year after surgery. Using the Knee Society clinical rating system 149 knees or 84.2 % were rated as having good to excellent results and 21 knees or 15.8 % as having fair to poor results. Overall, the mean preoperative knee score of 33.6 points had improved significantly to 80.7 points at the final follow-up (p boomerang osteotomy can create adequate valgus alignment in severe varus gonarthrosis. The one-year post-operative knee alignment of 11° valgus provided the most satisfactory results and that between six and 15° valgus the longest survival time.

Treatment of moderate hallux valgus by percutaneous, extra-articular reverse-L Chevron (PERC) osteotomy.

Science.gov (United States)

Lucas y Hernandez, J; Golanó, P; Roshan-Zamir, S; Darcel, V; Chauveaux, D; Laffenêtre, O

2016-03-01

The aim of this study was to report a single surgeon series of consecutive patients with moderate hallux valgus managed with a percutaneous extra-articular reverse-L chevron (PERC) osteotomy. A total of 38 patients underwent 45 procedures. There were 35 women and three men. The mean age of the patients was 48 years (17 to 69). An additional percutaneous Akin osteotomy was performed in 37 feet and percutaneous lateral capsular release was performed in 22 feet. Clinical and radiological assessments included the type of forefoot, range of movement, the American Orthopedic Foot and Ankle (AOFAS) score, a subjective rating and radiological parameters. The mean follow-up was 59.1 months (45.9 to 75.2). No patients were lost to follow-up. The mean AOFAS score increased from 62.5 (30 to 80) pre-operatively to 97.1 (75 to 100) post-operatively. A total of 37 patients (97%) were satisfied. At the last follow up there was a statistically significant decrease in the hallux valgus angle, the intermetatarsal angle and the proximal articular set angle. The range of movement of the first metatarsophalangeal joint improved significantly.. There was more improvement in the range of movement in patients who had fixation of the osteotomy of the proximal phalanx. Preliminary results of this percutaneous approach are promising. This technique is reliable and reproducible. Its main asset is that it maintains an excellent range of movement. The PERC osteotomy procedure is an effective approach for surgical management of moderate hallux valgus which combines the benefits of percutaneous surgery with the versatility of the chevron osteotomy whilst maintaining excellent first MTPJ range of motion. ©2016 The British Editorial Society of Bone & Joint Surgery.

Risks in surgery-first orthognathic approach: complications of segmental osteotomies of the jaws. A systematic review.

Science.gov (United States)

Pelo, S; Saponaro, G; Patini, R; Staderini, E; Giordano, A; Gasparini, G; Garagiola, U; Azzuni, C; Cordaro, M; Foresta, E; Moro, A

2017-01-01

To date, no systematic review has been undertaken to identify the complications of segmental osteotomies. The aim of the present systematic review was to analyze the type and incidence of complications of segmental osteotomies, as well as the time of subjective and/or clinical onset of the intra- and post-operative problems. A search was conducted in two electronic databases (MEDLINE - Pubmed database and Scopus) for articles published in English between 1 January 2000 and 30 August 2015; only human studies were selected. Case report studies were excluded. Two independent researchers selected the studies and extracted the data. Two studies were selected, four additional publications were recovered from the bibliography search of the selected articles, and one additional article was added through a manual search. The results of this systematic review demonstrate a relatively low rate of complications in segmental osteotomies, suggesting this surgical approach is safe and reliable in routine orthognathic surgery. Due to the small number of studies included in this systematic review, the rate of complication related to surgery first approach may be slightly higher than those associated with traditional orthognathic surgery, since the rate of complications of segmental osteotomies must be added to the complication rate of basal osteotomies. A surgery-first approach could be considered riskier than a traditional one, but further studies that include a greater number of subjects should be conducted to confirm these findings.

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.

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...

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

Chemical risk factors responsible for the formation of wedge-shaped lesions

Directory of Open Access Journals (Sweden)

Perić Dejan

2015-01-01

Full Text Available Introduction: Non-carious tooth substances loss pose a major health problem of a modern man. The literature often collectively describes all non-carious lesions and is therefore difficult to compare results obtained by different authors. Chemical factors are one of the predisposing factors responsible for the formation of wedge-shaped erosions. Aim: Examination of chemical risk factors as one of the predisposing causes responsible for the formation of wedge-shaped lesions. Method: We examined 62 patients with wedge-shaped erosions (mean age 45.52 ± 12.03 years, 58.1% of men and 60 patients without erosions in the control group (mean age 34.40 ± 9.28 years, 60% men . The entire examination was completed by using a questionnaire at the Dental Clinic of the University of Pristina - Kosovska Mitrovica. salivary pH was measured by the pH meter. Results: The results show that the wedge-shaped lesions often occur equally in both men and women. Considerably often it might appear in older people but can also occur in teenagers. Patients with wedge-shaped erosion have increased acidity of saliva, a heightened sense of acid in the mouth and consume a lot more carbonated drinks compared to patients without erosions. Conclusion: Wedge-shaped lesions are more common in people older than 40 years. Taking into account the results obtained in this study it can be concluded that the chemical risk factors truly fall within the predisposing factors that may be responsible for the creation of wedge-shaped erosions.

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

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))

BILATERAL SAGITAL SPLIT OSTEOTOMY PADA MANDIBULA PROGNATI

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Pradono Pradono

2015-07-01

Full Text Available A young girl 20 years old with mandibular prognathism, has been treated with orthodontics and surgical treatment in between. Mandibular set back was done intra orally 5 mm length and bilateral sagital split ramus osteotomy method. And rigid fixation was done by inserting three 2 mm bicortical screws for stabilizing the fragment. This method allowed the bony segments to heal properly and allowed the patients to function sooner.

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.

Comparative Evaluation of Cell Viability Immediately After Osteotomy for Implants With Drills and Piezosurgery: Immunohistochemistry Analysis.

Science.gov (United States)

Pereira, Cassiano Costa Silva; Batista, Fábio Roberto de Souza; Jacob, Ricardo Garcia Mureb; Nogueira, Lamis Meorin; Carvalho, Abrahão Cavalcante Gomes de Souza; Gealh, Walter Cristiano; Garcia-Júnior, Idelmo Rangel; Okamoto, Roberta

2018-05-08

To evaluate the effect of reusing drills and piezosurgery tips during implant osteotomy on immediate bone cell viability through immunohistochemical analysis. Six male rabbits were divided into 2 groups and then divided into 5 subgroups-correspond to drills and tips used 10, 20, 30, 40, and 50 times, respectively. All animals received 10 osteotomies in each tibia, by use of the classic drilling procedure in one group (G1) and the piezosurgery device in the other group (G2). For immunohistochemical technique were utilized the osteoprotegerin, RANKL, osteocalcin, and caspase 3. Control procedures were performed by omitting the primary antibodies (negative control). Bone formation and resorption responses presented in more intense way during the piezosurgery. The expression of osteocalcin had become quite intense in piezosurgery groups, but with reduced immunostaining from the 30th osteotomy. The caspase 3 showed the viability of the osteoblast from the 20th osteotomy with piezosurgery and remained constant until the 50th. Piezosurgery provides greater osteoblastic cell viability than the system of conventional drilling. This study will provide data so that the authors can recycle the drills and tips for implant placement, thus enabling a better cell viability for osseointegration.

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)

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

W/M serrated osteotomy for infantile Blount's disease in Ghana ...

African Journals Online (AJOL)

2015-10-30

Oct 30, 2015 ... surgical treatment is well suited for developing countries. This study describes .... with infantile Blount's are included for analysis. In this study, we are ... To increase the stability of the osteotomy, the teeth had to be pointed (at ...

Trans trochanteric approach with coronal osteotomy of the great trochanter

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Steffann Francois

2015-01-01

Full Text Available Several surgical approaches could be used in hip arthroplasty or trauma surgery: anterior, anterolateral, lateral, posterior (with or without trochanterotomy, using or not an orthopedic reduction table. Subtrochanteric and extra-capsular trochanteric fractures (ECTF are usually treated by internal fixation with mandatory restrictions on weight bearing. Specific complications have been widely described. Mechanical failures are particularly high in unstable fractures. Hip fractures are a major public health issue with a mortality rate of 12%–23% at 1 year. An alternative option is to treat ECTF by total hip arthroplasty (THA to prevent decubitus complications, to help rapid recovery, and to permit immediate weight bearing as well as quick rehabilitation. However, specific risks of THA have to be considered such as dislocation or cardiovascular failure. The classical approach (anterior or posterior requires the opening of the joint and capsule, weakening hip stability and the repair of the great trochanter is sometimes hazardous. For 15 years, we have been treating unstable ECTF by THA with cementless stem, dual mobility cup (DMC, greater trochanter (GT reattachment, and a new surgical approach preserving capsule, going through the fracture and avoiding joint dislocation. Bombaci first described a similar approach in 2008; our trans fractural digastric approach (medial gluteus and lateral vastus is different. A coronal GT osteotomy is performed when there is no coronal fracture line. It allows easy access to the femoral neck and acetabulum. The THA is implanted without femoral internal rotation to avoid extra bone fragment displacement. With pre-operative planning, cup implantation is easy and stem positioning is adjusted referring to the top of the GT after trial reduction and preoperative planning. The longitudinal osteotomy and trochanteric fracture are repaired with wires and the digastric incision is closed. This variant of Bombaci

Minimally invasive distal first metatarsal osteotomy can be an option for recurrent hallux valgus.

Science.gov (United States)

Magnan, Bruno; Negri, Stefano; Maluta, Tommaso; Dall'Oca, Carlo; Samaila, Elena

2018-01-12

Recurrence rate of surgical treatment of hallux valgus ranges in the literature from 2.7% to 16%, regardless of used procedure. In this study, long-term results of a minimally invasive distal osteotomy of the first metatarsal bone for treatment of recurrent hallux valgus are described. 32 consecutive percutaneous distal osteotomies of the first metatarsal were performed in 26 patients for treatment of recurrent hallux valgus. Primary surgery had been soft tissue procedures in 8 cases (25%), first metatarsal or phalangeal osteotomies in 19 cases (59.4%) and Keller procedures in 5 cases (15.6%). Patients were assessed with a mean follow-up of 9.8±4.3 years. All patients reported the disappearance or reduction of the pain. The mean overall AOFAS score improved from 46.9±17.8 points to 85.2±14.9 at final follow-up. The mean hallux valgus angle decreased from 26.1±9.1 to 9.7±5.4°, the intermetatarsal angle decreased from 11.5±4.5 to 6.7±4.0°. No major complications were recorded with a re-recurrence rate of 3.1% (1 case). Percutaneous distal osteotomy of the first metatarsal can be a reliable and safe surgical option in the recurrent hallux valgus with low complication rate and the advantages of a minimally invasive surgery. IV, Retrospective Case Series. Copyright © 2018 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

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...

Modern Microsurgical Resection of Olfactory Groove Meningiomas by Classical Bicoronal Subfrontal Approach without Orbital Osteotomies.

Science.gov (United States)

Farooq, Ghulam; Rehman, Lal; Bokhari, Irum; Rizvi, Syed Raza Hussain

2018-01-01

The olfactory groove meningioma has always been surgically challenging. The common microscopic surgical procedures exercised involve modification of pterional or sub-frontal approaches with or without orbital osteotomies. However, we believe that orbital osteotomies are not mandatory to achieve gross total resection. Hence, this study was performed to evaluate the surgical outcomes of olfactory groove meningioma with bicoronal sub frontal approach but without orbital osteotomies. The study was performed by reviewing the medical charts, neuroimaging data, and follow-up data of 19 patients who were treated micro surgically for olfactory groove meningioma without orbital osteotomies in our department. Mean overall follow up period of our study was 5 years. Statistical analysis was done by means of IBM SPSS Software version 19. Nineteen patients (1 male and 18 female patients, with an age range of 35-67 years; average age of patients' 51±7.5 years) of OGM were managed in our department. All patients were evaluated by MRI Brain with and without Gadolinium, CTA, CT Scan both axial and Coronal sequences. Most common symptom reported was head ache (80%), others include; urinary incontinence (26%), seizures (78%), decreased visual acuity (79%), papilledema (74%), personality changes (68%) and olfactory loss was reported in 57% of the patients. Post-operative complications include; CSF accumulation (5%), hematoma at tumor bed (10%), skin infection (5%) and mild post-operative brain edema (26%). Mortality rate was 5%. During 5 years of follow-up, we recorded one recurrence which was after 26 months and successfully removed in reoperation. Bi-coronal sub frontal approach appears to be an excellent technique for Olfactory Meningioma removal as practiced by most neurosurgeons. Nevertheless, it is not mandatory to carry out orbital osteotomy to acquire optimal surgical outcome as is advocated by some Authors.

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.

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.

Closing the Wedge: Search Strategies for Extended Higgs Sectors with Heavy Flavor Final States

CERN Document Server

Gori, Stefania; Shah, Nausheen R.; Zurek, Kathryn M.

2016-01-01

We consider search strategies for an extended Higgs sector at the high-luminosity LHC14 utilizing multi-top final states. In the framework of a Two Higgs Doublet Model, the purely top final states ($t\\bar t, \\, 4t$) are important channels for heavy Higgs bosons with masses in the wedge above $2\\,m_t$ and at low values of $\\tan\\beta$, while a $2 b 2t$ final state is most relevant at moderate values of $\\tan \\beta$. We find, in the $t\\bar t H$ channel, with $H \\rightarrow t \\bar t$, that both single and 3 lepton final states can provide statistically significant constraints at low values of $\\tan \\beta$ for $m_A$ as high as $\\sim 750$ GeV. When systematics on the $t \\bar t$ background are taken into account, however, the 3 lepton final state is more powerful, though the precise constraint depends fairly sensitively on lepton fake rates. We also find that neither $2b2t$ nor $t \\bar t$ final states provide constraints on additional heavy Higgs bosons with couplings to tops smaller than the top Yukawa due to expec...

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.

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.

Structural and ultrastructural analyses of bone regeneration in rabbit cranial osteotomy: Piezosurgery versus traditional osteotomes.

Science.gov (United States)

Anesi, Alexandre; Ferretti, Marzia; Cavani, Francesco; Salvatori, Roberta; Bianchi, Michele; Russo, Alessandro; Chiarini, Luigi; Palumbo, Carla

2018-01-01

Clinical advantages of piezosurgery have been already proved. However, few investigations have focused on the dynamics of bone healing. The aim of this study was to evaluate, in adult rabbits, bone regeneration after cranial linear osteotomies with two piezoelectrical devices (Piezosurgery ® Medical - PM and Piezosurgery ® Plus - PP), comparing them with conventional rotary osteotomes (RO). PP was characterized by an output power three times higher than PM. Fifteen days after surgery, histomorphometric analyses showed that the osteotomy gap produced with PM and PP was about half the size of that produced by RO, and in a more advanced stage of recovery. Values of regenerated bone area with respect to the total osteotomy area were about double in PM and PP samples compared with RO ones, while the number of TRAP-positive (tartrate-resistant acid phosphatase positive) osteoclasts per linear surface showed a significant increase, suggesting greater bone remodelling. Under scanning electron microscopy, regenerated bone displayed higher cell density and less mineralized matrix compared with pre-existent bone for all devices used. Nanoindentation tests showed no changes in elastic modulus. In conclusion, PM/PP osteotomies can be considered equivalent to each other, and result in more rapid healing compared with those using RO. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

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.

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

Endoscopic-assisted osteotomies for the treatment of craniosynostosis.

Science.gov (United States)

Hinojosa, J; Esparza, J; Muñoz, M J

2007-12-01

The development of multidisciplinar units for Craniofacial Surgery has led to better postoperative results and a considerable decrease in morbidity in the treatment of complex craniofacial patients. Standard correction of craniosynostosis involves calvarial remodeling, often considerable blood losses that need to be replaced and lengthy hospital stay. The use of minimally invasive techniques for the correction of some of these malformations are widespread and allows the surgeon to minimize the incidence of complications by means of a decreased surgical time, blood salvage, and shortening of postoperative hospitalization in comparison to conventional craniofacial techniques. Simple and milder craniosynostosis are best approached by endoscopy-assisted osteotomies and render the best results. Extended procedures other than simple suturectomies have been described for more severe patients. Different osteotomies resembling standard fronto-orbital have been developed for the correction, and the use of postoperative cranial orthesis may improve the final cosmetic appearance. Thus, endoscopic-assisted procedures differ from the simple strategy of single suture resection that rendered insufficient results in the past, and different approaches can be tailored to solve these cases in patients in the setting of a case-to-case bases.

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.

Heat generated by dental implant drills during osteotomy-a review: heat generated by dental implant drills.

Science.gov (United States)

Mishra, Sunil Kumar; Chowdhary, Ramesh

2014-06-01

Osseointegration is the more stable situation and results in a high success rate of dental implants. Heat generation during rotary cutting is one of the important factors influencing the development of osseointegration. To assess the various factors related to implant drills responsible for heat generation during osteotomy. To identify suitable literature, an electronic search was performed using Medline and Pubmed database. Articles published in between 1960 to February 2013 were searched. The search is focused on heat generated by dental implant drills during osteotomy. Various factors related to implant drill such effect of number of blades; drill design, drill fatigue, drill speed and force applied during osteotomies which were responsible for heat generation were reviewed. Titles and abstracts were screened, and literature that fulfilled the inclusion criteria was selected for a full-text reading. The initial literature search resulted in 299 articles out of which only 70 articles fulfils the inclusion criteria and were included in this systematic review. Many factors related to implant drill responsible for heat generation were found. Successful preparation of an implant cavity with minimal damage to the surrounding bone depends on the avoidance of excessive temperature generation during surgical drilling. The relationship between heat generated and implant drilling osteotomy is multifactorial in nature and its complexity has not been fully studied. Lack of scientific knowledge regarding this issue still exists. Further studies should be conducted to determine the various factors which generate less heat while osteotomy such as ideal ratio of force and speed in vivo, exact time to replace a drill, ideal drill design, irrigation system, drill-bone contact area.

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...

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

Influence of Closed Stator Slots on Cogging Torque

DEFF Research Database (Denmark)

Ion, Trifu; Leban, Krisztina Monika; Ritchie, Ewen

2013-01-01

Cogging torque results due interaction of magnetic field of magnets and stator slots, and have negative effects on permanent magnet machines such as vibrations, noise, torque ripples and problems during turbine start-up and cut-in. In order to reduce cogging torque this paper presents a study...... of influence of closed stator slots on cogging torque using magnetic slot wedges....

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.

Limb shortening osteotomy in a patient with achondroplasia and leg length difference after total hip arthroplasty

Directory of Open Access Journals (Sweden)

Christian L. Galata

2013-07-01

Full Text Available Introduction: Achondroplasia is the most common reason for disproportionate short stature. Normally, orthopedic limb lengthening procedures must be discussed in the course of this genetic disorder and have been successful in numerous achondroplastic patients in the past. In some cases, the disease may lead to leg length differences with need for surgical correction. Case Report: We report a case of achondroplastic dysplastic coxarthrosis with symptomatic leg length difference after bilateral total hip arthroplasty in a 52-year-old female patient, in which a distal femoral shortening osteotomy was successfully performed. Conclusion: Femoral shortening osteotomy is very uncommon in patients with achondroplasia. We conclude, however, that in rare cases it can be indicated and provide the advantage of shorter operation time, less perioperative complications and faster recovery compared to leg lengthening procedures. Keywords: Achondroplasia, dysplastic coxarthrosis, limb shortening, distal femur osteotomy.

Trochanteric reduction osteotomy as a treatment for refractory trochanteric bursitis

NARCIS (Netherlands)

Govaert, L. H. M.; van der Vis, H. M.; Marti, R. K.; Albers, G. H. R.

2003-01-01

We describe a new operative procedure for patients with chronic trochanteric bursitis. Between March 1994 and May 2000, a trochanteric reduction osteotomy was performed on ten patients (12 hips). All had received conservative treatment for at least one year. Previous surgical treatment with a

Bilateral sagittal split osteotomy versus distraction osteogenesis for mandibular advancements

NARCIS (Netherlands)

Baas, E.M.

2015-01-01

The aim of this thesis was to compare the treatment modality of distraction osteogenesis (DO) with the gold standard for mandibular advancement surgery. In fact we compare distraction osteogenesis with the standard of care, which is a conventional bilateral sagittal split osteotomy as described by

Comparison of clinical outcomes using a Piezosurgery device vs. a conventional osteotome for lateral osteotomy in rhinoplasty.

Science.gov (United States)

Koc, Bulent; Koc, Eltaf Ayca; Erbek, Selim

2017-08-01

Our aim for this study was to evaluate and compare the clinical outcomes in patients who underwent lateral osteotomy with a Piezosurgery device or a conventional osteotome in open-technique rhinoplasty. This cohort trial involved 65 patients (36 women and 29 men; average age: 23.6 ± 5.71 yr) who underwent surgery between May 2015 and January 2016. Piezosurgery was used for lateral osteotomy in 32 patients, whereas 33 patients underwent conventional external osteotomy. These 2 groups were compared for duration of surgery, perioperative bleeding, postoperative edema, ecchymosis, pain, and patient satisfaction on the first and seventh postoperative days. The Piezosurgery group revealed significantly more favorable outcomes in terms of edema, ecchymosis, and hemorrhage on the first day postoperatively (p Piezosurgery group. Hemorrhage was similar in both groups on the seventh postoperative day (p = 0.67). The Piezosurgery group not only experienced less pain on the first postoperative day (p Piezosurgery may be a promising, safe, and effective method for lateral osteotomy, a critical step in rhinoplasty. The time interval necessary for the learning curve is counteracted by the comfort and satisfaction of both patients and surgeons.

Comparative Study of Skeletal Stability between Postoperative Skeletal Intermaxillary Fixation and No Skeletal Fixation after Bilateral Sagittal Split Ramus Osteotomy

DEFF Research Database (Denmark)

Hartlev, Jens; Godtfredsen, Erik; Andersen, Niels Trolle

2014-01-01

OBJECTIVES: The purpose of the present study was to evaluate skeletal stability after mandibular advancement with bilateral sagittal split osteotomy. MATERIAL AND METHODS: Twenty-six patients underwent single-jaw bilateral sagittal split osteotomy (BSSO) to correct skeletal Class II malocclusion....

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

Application of super-omni wedge concept to conformal radiotherapy treatment planning

International Nuclear Information System (INIS)

Dai Jianrong; Fu Weihua; Hu Yimin

2004-01-01

Objective: To describe a method which can optimize beam weight, wedge angle, and wedge orientation simultaneously by combining the super-omni wedge (SOW) concept with the function of beam weight optimization provided by a commercial treatment planning system. Methods: A five-step procedure including: Step 1. To set up four 60 degree nominal wedged beams for each beam direction with the wedge orientations of 'LEFT', 'IN', 'RIGHT', 'OUT', respectively; Step 2. To define an optimization request, including an optimization goal and constraints. Authors use CMS Focus treatment planning system which allows us to choose 'maximize target dose' or 'minimize critical structure dose' as the optimization goal, and to set minimum target dose, maximum target dose, and maximum average dose of critical structures as constraints. Then the optimization process was launched as step 3; Step 4. To evaluate the plan using isodose distributions and dose-volume histograms. If acceptable, go to Step 5. Otherwise, go back to Step 2 to modify optimization constraints; and Step 5. Transform the SOW beams into the beams of omni wedge so as to reduce the number of to-be-delivered beams. Results: This procedure was found being able to demonstrate successfully in two clinical cases: an esophageal carcinoma and a brain tumor. Compared with manually designed plan, the optimized plan showed better dose homogeneity in the targets and better sparing of the critical structures. Conclusions: This method described is able to optimize beam weights while working with a treatment planning system. Not only does it improve treatment plans' quality, but also shorten the treatment planning process

Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study.

Science.gov (United States)

Ge, Jing; Yang, Chi; Zheng, Jia-Wei; He, Dong-Mei; Zheng, Ling-Yan; Hu, Ying-Kai

2014-11-01

Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects. A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics. The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration. The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

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

Three-dimensional translations following posterior three-column spinal osteotomies for the correction of severe and stiff kyphoscoliosis.

Science.gov (United States)

Li, Xueshi; Huang, Zifang; Deng, Yaolong; Fan, Hengwei; Sui, Wenyuan; Wang, Chongwen; Yang, Junlin

2017-12-01

Posterior three-column spinal osteotomies were shown to be effective to treat severe and stiff kyphoscoliosis. Translations at the site of osteotomy after deformity correction were commonly seen intraoperatively, which might cause potential neurologic deficits. However, this phenomenon was not thoroughly discussed in the current literature. This study aimed to evaluate the three-dimensional (3D) translations at the three-column osteotomy site and their effects on neurologic outcome in the surgical correction of severe and stiff kyphoscoliosis. A retrospective study was carried out. Sixty-nine patients treated by posterior three-column spinal osteotomy for severe kyphoscoliosis of idiopathic, congenital, neuromuscular, neurofibromatosis, and tuberculosis origin were included. General, coronal, and sagittal translations were graded three-dimensionally according to the theory of Meyerding. The charts of 69 clinical patients with severe and stiff kyphoscoliosis treated by posterior three-column osteotomy from January 2013 to June 2015 were reviewed. There were 35 male patients with an average age of 21.5 years and 34 female patients with an average age of 22.5 years. The etiologies of these spinal deformities were idiopathic, congenital, neuromuscular, neurofibromatosis, and tuberculosis. According to our classification system of spinal cord neurologic function, there were 41 type A, 13 type B, and 15 type C cases. The 3D spine models were reconstructed from thin-sliced computed tomography (CT) scan, and the 3D translations at the three-column osteotomy site were graded and analyzed. The incidences of general translation (GT), frontal translation (FT), and sagittal translation (ST) were 62.3%, 52.2%, and 26.1%. The incidence of evoked potential (EP) change in cases with GT/FT being or more than grade II (GT, 42.9%; FT, 50.0%) was significantly higher than that with GT/FT being less than grade II (GT, 16.7%; FT, 18.2%), whereas the incidence of EP change in cases with

Skull base tumors: a comprehensive review of transfacial swing osteotomy approaches.

Science.gov (United States)

Moreira-Gonzalez, Andrea; Pieper, Daniel R; Cambra, Jorge Balaguer; Simman, Richard; Jackson, Ian T

2005-03-01

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.

Wedge cells during regeneration of juvenile and adult feathers and their role in carving out the branching pattern of barbs.

Science.gov (United States)

Alibardi, Lorenzo

2007-01-01

The present ultrastructural study on regenerating feathers emphasizes the role of supportive cells in determining the branching pattern of barbs. Supportive cells are localized among developing barb and barbule cells, in marginal plates, and underneath the feather sheath, and their differentiative fate, in general, is a form of lipid degeneration. The Latter process determines the carving out of barb branching in both downfeathers and pennaceous feathers. In the latter feathers, some supportive cells (barb vane cells and cylindrical cells of marginal plates) degenerate within each barb ridge leaving separate barbules. Other supportive cells, here termed wedge cells, form columns of cornified material that merge into elongated corneous scaffolds localized among barbs and the rachis. This previously undescribed form of cornification of supportive cells derives from the aggregation of periderm and dense granules present in wedge cells. The latter cells give origin to a corneous material different from feather keratin that may initially sustain the early and soft barbules. After barbules are cornified the supportive cells scaffolds are eventually sloughed as the sheath breaks allowing the new feather to open up and form a planar vane. The corneous material of wedge cells may also contribute to molding of the overlapped nodes of barbule cells that form lateral spines or hooklets in mature barbules. Eventually, the disappearance of wedge cell scaffolding determines the regular spacing of barbs attached to the rachis in order to form a close vane.

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

Effect of surgical shoes on brake response time after first metatarsal osteotomy?a prospective cohort study

OpenAIRE

Dammerer, Dietmar; Braito, Matthias; Biedermann, Rainer; Ban, Michael; Giesinger, Johannes; Haid, Christian; Liebensteiner, Michael C.; Kaufmann, Gerhard

2016-01-01

Background The aim of this study is to assess patients? driving ability when wearing surgical shoes following right-sided first metatarsal osteotomy. Methods From August 2013 to August 2015, 42 consecutive patients (mean age 54.5?years) with right-sided hallux valgus deformity underwent first metatarsal osteotomy. Patients were tested for brake response time (BRT) 1?day preoperatively (control run) and at 2 and 6?weeks postoperatively. Two different types of foot orthosis were investigated. B...

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

Neck osteotomy for malunion of neglected radial neck fractures in children: a report of 2 cases.

Science.gov (United States)

Ceroni, Dimitri; Campos, José; Dahl-Farhoumand, Agnes; Holveck, Jérôme; Kaelin, André

2010-01-01

Radial neck fractures are a common injury in children as a result of a fall on an extended and supinated outstretched hand. We present 2 cases of osteotomy of the neck of the radius performed in 2 children with neglected radial neck fractures. Preoperatively, both patients complained of pain and severely reduced mobility of the elbow. Surgery was performed at 6 weeks and 3 months, respectively, after the initial injury and the 2 children were reviewed at 6 and 16 months follow-up. Osteotomies healed within the usual time and no avascular necrosis of the radial head, proximal radioulnar synostosis, or myositis ossificans were observed. The Mayo Elbow Performance Index Score improved significantly after the operation with the 2 patients rated as excellent. In this small series, we present a novel technique of proximal osteotomy of the radius to correct this deformity in children. Case series, level IV evidence.

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.

Does intraoperative navigation improve the accuracy of mandibular angle osteotomy: Comparison between augmented reality navigation, individualised templates and free-hand techniques.

Science.gov (United States)

Zhu, Ming; Liu, Fei; Zhou, Chaozheng; Lin, Li; Zhang, Yan; Chai, Gang; Xie, Le; Qi, Fazhi; Li, Qingfeng

2018-04-11

Augmented reality (AR)-based navigation surgery has evolved to be an advanced assisted technology. The aim of this study is to manifest the accuracy of AR navigation for the intraoperative mandibular angle osteotomy by comparing the navigation with other interventional techniques. A retrospective study was conducted with 93 post-surgical patients with mandibular angle hypertrophy admitted at our plastic and reconstructive surgery department between September 2011 and June 2016. Thirty-one patients received osteotomy conducted using a navigation system based on augmented reality (AR group), 28 patients received osteotomy conducted using individualised templates (IT group) and the remaining 34 patients received osteotomy performed by free hand (free-hand group). The post-operative computed tomography (CT) images were reviewed and analysed by comparing with pre-surgical planning generated by three-dimensional (3D) software. The preparation time, cutting time, whole operating time and discrepancy in osteotomy lines were measured. The preparation time was much shorter for the free-hand group than that for the AR group and the IT group (P  0.05). In addition, the discrepancy in osteotomy lines was lower for the AR group and in the IT group than for the free-hand group (P < 0.01). The navigation system based on AR has a higher accuracy, more reliability and better user friendliness for some particular clinical procedures than for other techniques, which has a promising clinical prospect. Copyright © 2018. Published by Elsevier Ltd.

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.)

Analysis of Fault Spacing in Thrust-Belt Wedges Using Numerical Modeling

Science.gov (United States)

Regensburger, P. V.; Ito, G.

2017-12-01

Numerical modeling is invaluable in studying the mechanical processes governing the evolution of geologic features such as thrust-belt wedges. The mechanisms controlling thrust fault spacing in wedges is not well understood. Our numerical model treats the thrust belt as a visco-elastic-plastic continuum and uses a finite-difference, marker-in-cell method to solve for conservation of mass and momentum. From these conservation laws, stress is calculated and Byerlee's law is used to determine the shear stress required for a fault to form. Each model consists of a layer of crust, initially 3-km-thick, carried on top of a basal décollement, which moves at a constant speed towards a rigid backstop. A series of models were run with varied material properties, focusing on the angle of basal friction at the décollement, the angle of friction within the crust, and the cohesion of the crust. We investigate how these properties affected the spacing between thrusts that have the most time-integrated history of slip and therefore have the greatest effect on the large-scale undulations in surface topography. The surface position of these faults, which extend through most of the crustal layer, are identifiable as local maxima in positive curvature of surface topography. Tracking the temporal evolution of faults, we find that thrust blocks are widest when they first form at the front of the wedge and then they tend to contract over time as more crustal material is carried to the wedge. Within each model, thrust blocks form with similar initial widths, but individual thrust blocks develop differently and may approach an asymptotic width over time. The median of thrust block widths across the whole wedge tends to decrease with time. Median fault spacing shows a positive correlation with both wedge cohesion and internal friction. In contrast, median fault spacing exhibits a negative correlation at small angles of basal friction (laws that can be used to predict fault spacing in

[Posterior partial trochanteric osteotomy for the treatment of the roof involved acetabular fractures].

Science.gov (United States)

Wang, Pan-Feng; Xu, Shuo-Gui; Zhang, Chun-Cai; Fu, Qing-Ge; Zhang, Yun-Tong; Liu, Xin-Wei; Niu, Yun-Fei; Tang, Yang

2013-11-01

To introduce a new trochanteric osteotomy,and evaluate the outcome of the procedure combined a posterior lateral approach in treating acetabular fractures which involving the roof. Between March 2007 and Novmber 2010,30 patients with displaced acetabular fractures involving the dome need trochanteric osteotomy were retrospectively reviewed. There were 21 males and 9 females,ranging in age from 18 to 70 years with an average of 35.2 years at the time of injury. According to Letournel-Judet classification, there were 10 posterior wall fractures,7 posterior column fractures,5 transverse fractures, 2 T-shape fractures, 1 transverse associated with posterior wall fracture, 3 posterior column and wall fractures and 2 bicolumn fractures. The standards of Matta,the modified Merle d'Aubigne-Postel, Medical Research Council were respectively used to evaluate the reduction result, function of hip joint and the strength of hip abduction. All patients were followed up with an average time of 25 months (18 to 40) and all osteotomy sites obtained bone union with an average time of 8.4 weeks (6 to 12). No bone non-union, bone block displaceing, internal fixation looseing and breaking,infection of deep part were found. Seventeen patients got anatomic reduction, 12 got satisfied reduction, and 1 got unsatisfied result according to the criteria of Matta. At final follow-up, function of hip joint obtained excellent results in 11 cases, good in 15, fair in 3 and poor in 1. The strength of the abductors of 3 patients were grade 4 and 27 patients were grade 5. Posterior partial great trochanteric osteotomy can enhance the exposure and provide a more accurate reduction and degrade the difficulty of acetabular fracture fixation without increasing the risk of complications. The method provide a new way for the treatment of the roof involved acetabular fractures.

Distal femoral osteotomy in genovalgum: internal fixation with blade plate versus casting.

Science.gov (United States)

Makhmalbaf, Hadi; Moradi, Ali; Ganji, Saeid

2014-10-01

To compare the results of two different ways of distal femoral osteotomy stabilization in patients suffering from genuvalgum: internal fixation with plate, and casting. In a non-randomized prospective study, after distal femoral osteotomy with the zigzag method, patients were divided into two groups: long leg casting, and internal fixation with blade plate. For all patients, questionnaires were filled to obtain data. Information such as range of motion, tibiofemoral anatomical angle and complications were recorded. 38 knees with valgus deformity underwent distal femoral supracondylar osteotomy. (8 with plaster cast and 30 with internal fixation using a blade plate). Preoperative range of motion was 129±6° and six months later it was 120±14°. The preoperative tibiofemoral angle was 32±6°; postoperative tibiofemoral angles were 3±3°, 6±2°, and 7±3° just after operation, six months, and two years later, respectively. Although this angle was greater among the group stabilized with a cast, this difference was not statistically significant. In postoperative complications, over-correction was found in five, recorvatom deformity in one, knee stiffness in three and superficial wound infection was recorded in three knees. There is no prominent difference in final range of motion and alignment whether fixation is done with casting or internal fixation. However, the complication rate seems higher in the casting method.

Minimally Invasive Distal Metatarsal Osteotomy for Mild-to-Moderate Hallux Valgus Deformity

Directory of Open Access Journals (Sweden)

Yu-Chuan Lin

2009-08-01

Full Text Available Minimally invasive surgery has recently been introduced for foot and ankle surgery, and hallux valgus surgery is no exception. The purpose of our study was to analyze the early results and to present our experience of minimally invasive distal metatarsal osteotomy in correcting mild-to-moderate hallux valgus deformities. Between September 2005 and December 2006, 31 consecutive patients (47 feet with mild-to-moderate hallux valgus deformities underwent minimally invasive distal metatarsal osteotomies. The clinical and radiographic outcomes were assessed. The satisfaction rate was 90.32%. The mean total American Orthopedic Foot and Ankle Society halluxmetatarsophalangeal-interphalangeal scale was 92.7 points. Complications included two (4.26% episodes of stiffness, six (12.77% episodes of pin tract infection, and one (2.13% deep infection. There were no cases with nonunion, malunion, overcorrection, transfer metatarsalgia or osteonecrosis. On weight-bearing anteroposterior foot radiographs, the mean hallux valgus angle and first intermetatarsal angle corrections were 11.8° and 6.3°, respectively, which is a statistically significant difference (p < 0.001 between the preoperative and postoperative status. Here, minimally invasive distal metatarsal osteotomy was associated with good satisfaction, functional improvement and low complication rates. This technique offers an effective, safe and simple way to treat hallux valgus with a first intermetatarsal angle less than 15°.

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

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

Triple osteotomy for the correction of severe hallux valgus deformity: Patient reported outcomes and radiological evaluation.

Science.gov (United States)

Booth, Sean; Bhosale, Abhijit; Mustafa, Abubakar; Shenoy, Ravi; Pillai, Anand

2016-08-01

Symptomatic Hallux valgus can be treated with metatarsal osteotomy combined with proximal phalangeal osteotomy, however this might not be sufficient to treat severe HV deformities. Fifteen feet in eleven female patients treated with double first metatarsal and proximal phalanx osteotomies without lateral release were prospectively studied and outcome measures including radiological angles and validated patient reported outcome scores collected. Mean radiological follow up was 15 months and PROMs data 17 months. Mean hallux valgus and intermetatarsal angles were corrected from 45 to 24.7° and 18.7 to 7.4° respectively. There was an eight degree recurrence of hallux valgus angle. There was no wound problems, non-unions or evidence of avascular necrosis. The EQ-5D descriptive index showed a non-statistically significant improvement. All three elements of the MOxFQ score showed a statistically significant improvement: Forefoot pain (59-26.8), Walking and Stability (49.9-29.6) and Social Interaction (56.4-33.1) CONCLUSION: Triple osteotomy, without a lateral soft tissue release, leads to good radiological and functional outcomes in those with severe hallux valgus deformity. Patients need to be warned of the recovery time and potential for future metalwork removal. The risk of early recurrence suggests that a lateral release should be included in order to maintain a long lasting correction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Premaxillary osteotomy fixation in bilateral cleft lip/palate: Introducing a new technique

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Amin Rahpeyma

2016-04-01

Conclusion: In protruding premaxilla, osteotomy and fixation of premaxilla with miniplate to the vomer bone during alveolar bone grafting through a lip-split approach yielded satisfactory results in patients requiring secondary functional cheilorhinoplasty.

The role of trochanteric flip osteotomy in fixation of certain acetabular fractures

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Sandeep Gupta

2017-06-01

Conclusion: Trochanteric flip osteotomy is a very effective technique to fix certain acetabular fractures especially those with dome involvement. It is more accurate and associated with no significant complications compared with conventional way.

Comparison of two Methods of Lateral Osteotomies withwithout Subperiosteal Tunnel creation on Edema and Ecchymosis after Rhinoplasty.

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MR As’habyamin

2016-05-01

Full Text Available Introduction: Postoperative periorbital edema and ecchymosis is one of the main complication of rhinoplasty. This complication is mostly due to lateral osteotomy. During performing the endonasal lateral osteotomy, with the goal of reducing injury to surrounding tissues and reducing the postoperative edema and ecchymosis. The aim of this study goal was to determine whether creating a subperiosteal tunnel before lateral osteotomy had an effect on postoperative periorbital edema and ecchymosis. Methods: 102 patients were included in the study. They were underwent rhinoplasty. In each patients lateral osteotomies were carried out bilaterally, after creating a subperiosteal tunnel with periosteum elevator on a randomly chosen side and without creating a subperiosteal tunnel on the other side. The rest of the procedure was similar bilaterally. The patients were examined on the 2nd and 7th days after surgery. The levels of edema and periorbital ecchymosis were score by a different surgery who was unaware of the side with the periosteal tunnel, and the results were compared together. Results: According to the data analysis, there was no statistically significant difference between the severity of periorbital edema at the side with subperiosteal tunnel and the side without it on the 2nd and 7th days after surgery (P value=0/096 and Pvalue=0/252, respectively. There was not found any statistical significant between periorbital ecchymosis at the side with subperiosteal tunnel and the side without it on the 2nd and 7th days after surgery (P value=0/783 and Pvalue=0/094, respectively. Conclusions: Creating a subperiostal tunnel before lateral osteotomy in rhinoplasty does not influence on the severity of postoperative edema and ecchymosis.

Bone repair after osteotomy with diamond burs and CVD ultrasonic tips – histological study in rats

OpenAIRE

Matuda, Fábio S.; Pagani, Clovis; Miranda, Carolina B.; Crema, Aline A. S.; Brentel, Aline S.; Carvalho, Yasmin R.

2010-01-01

This study histologically evaluated the behavior of bone tissue of rats submitted to osteotomy with conventional diamond burs in high speed and a new ultrasonic diamond tips system (CVD – Chemical Vapor Deposition), at different study periods. The study was conducted on 24 Wistar rats. Osteotomy was performed on the posterior paws of each rat, with utilization of diamond burs in high speed under thorough water cooling at the right paw, and CVD tips at the left paw. Animals were killed a...

Supracondylar corrective osteotomy for cubitus varus--the internal rotation component and its importance. An unique bone experiment.

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Jimulia T

1994-10-01

Full Text Available In 20 patients with cubitus varus, a clinical test suggested by Yamamoto et al (1985 was carried out to measure the internal rotation. Average internal rotation was found to be 37.5 +/- 9.390. A correction for internal rotation was carried out for all the patients having angle more than 20 degrees. Following osteotomy, post-operative Yamamoto′s angle was measured and was found to be 8.85 +/- 6.5. An experiment was carried out on postmortem human humerus with cubitus varus. The internal rotation was measured with Kirschner wires and was found to be 30 degrees. Osteotomy was carried out to eliminate varus and correct internal rotation. Radiographs taken before and after the osteotomy confirmed the correction. We conclude that this derotation has to be corrected and Yamamoto′s test should be used to assess the correction.

Evaluation of Bernese periacetabular osteotomy: prospective studies examining projected load-bearing area, bone density, cartilage thickness and migration.

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Mechlenburg, Inger

2008-06-01

The typical dysplastic hip joint is characterised by maldirection of the acetabulum and femoral neck, insufficient coverage of the femoral head focally and globally and erosions of the limbus acetabuli (1). An unknown number of persons with hip dysplasia will suffer from pain in hip or groin, decreased hip function and development of osteoarthritis at a young age. The Bernese periacetabular osteotomy is performed to prevent osteoarthritis in patients with hip dysplasia and has been carried out at Aarhus University Hospital, Denmark since 1996 with more than 500 osteotomies performed. Throughout the years, research and quality improvement of the treatment has taken place and this PhD thesis is part of that process. The aims of this PhD thesis were to evaluate outcome aspects after periacetabular osteotomy in terms of I) estimating the projected loadbearing surface before and after periacetabular osteotomy, II) estimating bone density changes in the acetabulum after periacetabular osteotomy, III) developing a technique to precisely and efficiently estimate the thickness of the articular cartilage in the hip joint and IV) examining the stability of the re-orientated acetabulum after periacetabular osteotomy. In study I, we applied a stereologic method based on 3D computed tomography (CT) to estimate the projected loadbearing surface in six normal hip joints and in six dysplastic hips. The dysplastic hips were CT scanned before and after periacetabular osteotomy. We found that the average area of the projected loadbearing surface of the femoral head preoperatively was 7.4 (range 6.5-8.4) cm2 and postoperatively 11 (9.8-14.3) cm2. The area of the projected loadbearing surface was increased significantly with a mean of 49% (34-70%) postoperatively and thus comparable with the load-bearing surface in the normal control group. Double measurements were performed and the error variance of the mean was estimated to be 1.6%. The effect of overprojection, on the projected

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.

Outcomes in chevron osteotomy for Hallux Valgus in a large cohort

NARCIS (Netherlands)

van Groningen, B. (Bart); M.C.M. (Marieke) van der Steen,; M. Reijman (Max); Bos, J. (Janneke); Hendriks, J.G.E. (Johannes G.E.)

2016-01-01

textabstractClinical and radiological related outcomes have been reported for Chevron osteotomy as correction for mild to moderate hallux valgus, but only for relatively small patient series. Moreover, evaluation of the patient's point of view has mostly been conducted by means of more

Pre-operative simulation of periacetabular osteotomy via a three-dimensional model constructed from salt

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Fukushima Kensuke

2017-01-01

Full Text Available Introduction: Periacetabular osteotomy (PAO is an effective joint-preserving procedure for young adults with developmental dysplasia of the hip. Although PAO provides excellent radiographic and clinical results, it is a technically demanding procedure with a distinct learning curve that requires careful 3D planning and, above all, has a number of potential complications. We therefore developed a pre-operative simulation method for PAO via creation of a new full-scale model. Methods: The model was prepared from the patient’s Digital Imaging and Communications in Medicine (DICOM formatted data from computed tomography (CT, for construction and assembly using 3D printing technology. A major feature of our model is that it is constructed from salt. In contrast to conventional models, our model provides a more accurate representation, at a lower manufacturing cost, and requires a shorter production time. Furthermore, our model realized simulated operation normally with using a chisel and drill without easy breakage or fissure. We were able to easily simulate the line of osteotomy and confirm acetabular version and coverage after moving to the osteotomized fragment. Additionally, this model allowed a dynamic assessment that avoided anterior impingement following the osteotomy. Results: Our models clearly reflected the anatomical shape of the patient’s hip. Our models allowed for surgical simulation, making realistic use of the chisel and drill. Our method of pre-operative simulation for PAO allowed for the assessment of accurate osteotomy line, determination of the position of the osteotomized fragment, and prevented anterior impingement after the operation. Conclusion: Our method of pre-operative simulation might improve the safety, accuracy, and results of PAO.

Hydroelastic slamming of flexible wedges: Modeling and experiments from water entry to exit

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Shams, Adel; Zhao, Sam; Porfiri, Maurizio

2017-03-01

Fluid-structure interactions during hull slamming are of great interest for the design of aircraft and marine vessels. The main objective of this paper is to establish a semi-analytical model to investigate the entire hydroelastic slamming of a wedge, from the entry to the exit phase. The structural dynamics is described through Euler-Bernoulli beam theory and the hydrodynamic loading is estimated using potential flow theory. A Galerkin method is used to obtain a reduced order modal model in closed-form, and a Newmark-type integration scheme is utilized to find an approximate solution. To benchmark the proposed semi-analytical solution, we experimentally investigate fluid-structure interactions through particle image velocimetry (PIV). PIV is used to estimate the velocity field, and the pressure is reconstructed by solving the incompressible Navier-Stokes equations from PIV data. Experimental results confirm that the flow physics and free-surface elevation during water exit are different from water entry. While water entry is characterized by positive values of the pressure field, with respect to the atmospheric pressure, the pressure field during water exit may be less than atmospheric. Experimental observations indicate that the location where the maximum pressure in the fluid is attained moves from the pile-up region to the keel, as the wedge reverses its motion from the entry to the exit stage. Comparing experimental results with semi-analytical findings, we observe that the model is successful in predicting the free-surface elevation and the overall distribution of the hydrodynamic loading on the wedge. These integrated experimental and theoretical analyses of water exit problems are expected to aid in the design of lightweight structures, which experience repeated slamming events during their operation.

New Transition Wedge Design Composed by Prefabricated Reinforced Concrete Slabs

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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.

Planning for corrective osteotomy of the femoral bone using 3D-modeling. Part I

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Alexey G Baindurashvili

2016-09-01

Full Text Available Introduction. In standard planning for corrective hip osteotomy, a surgical intervention scheme is created on a uniplanar paper medium on the basis of X-ray images. However, uniplanar skiagrams are unable to render real spatial configuration of the femoral bone. When combining three-dimensional and uniplanar models of bone, human errors inevitably occur, causing the distortion of preset parameters, which may lead to glaring errors and, as a result, to repeated operations. Aims. To develop a new three-dimensional method for planning and performing corrective osteotomy of the femoral bone, using visualizing computer technologies. Materials and methods. A new method of planning for corrective hip osteotomy in children with various hip joint pathologies was developed. We examined the method using 27 patients [aged 5–18 years (32 hip joints] with congenital and acquired femoral bone deformation. The efficiency of the proposed method was assessed in comparison with uniplanar planning using roentgenograms. Conclusions. Computerized operation planning using three-dimensional modeling improves treatment results by minimizing the likelihood of human errors and increasing planning and surgical intervention  accuracy.

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.

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

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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.

One-stage lengthening and derotational osteotomy of the femur stabilised with a gamma nail.

Science.gov (United States)

van Doorn, R; Leemans, R; Stapert, J W

1999-12-01

To study the results of a one-stage lengthening and derotational osteotomy stabilised with a Gamma nail. Retrospective study. 2 hospitals, The Netherlands. 5 patients after failed osteosynthesis of femoral fractures. Mean lengthening of 3 cm and derotation of 30 degrees. Complications and functional results, after a mean follow-up of 43 months (range 30-57). Two patients required dynamisation and a cancellous bone graft to achieve union, which resulted in 1 and 1.5 cm loss of length. One patient had a temporary peroneal neurapraxy. No infections were observed. Our method is not an ultimate solution, but is suitable for one-stage lengthening and derotation osteotomies.

PROXIMAL FEMURAL VALGUS SUBTROCHANTERIC OSTEOTOMY FOR NON UNION OF TROCHANTERIC FRACTURES.

Science.gov (United States)

Silva, Paulo; Coelho, Danilo Lopes; Curi, Calim; de Oliveira, Leandro Alves; de Moraes, Frederico Barra; do Amaral, Rogério Andrade; Rebello, Percival Rosa

2012-01-01

To evaluate valgus subtrochanteric osteotomy for the treatment of trochanteric non-union. A retrospective study of cases series. From 1998 September to 2009 January, seventeen (17) cases with a diagnosis of non-union of trochanteric fracture were re-operated by the hip group of the Ortophaedic And Traumatology service of the Hospital Geral de Goiania (HGG). The patients presented pain at the fracture site, a femoral varus angle of less than 120°, and non-union of the fracture in the 3(rd) months after the initial surgery. Patients with ages ranging from 30 to 73 years, with a maximum follow-up of 09 years and minimum of 09 years. The mean time from first surgery to osteotomy was six months. Bone union was observed in 16 patients, with a mean union time of 12 weeks after surgery. The mean hip varus angle was 105(0) (120(0) to 90(0)). After surgery, the mean hip valgus angle was 144(0) (155(0) to 135(0)). We had one unsuccessful case; a 78-year old patient who had osteogtomy, fixed with DHS of 150(0), with valgization to 154(0). After six months of follow-up without union of the fracture, it was decided to perform total cemented hip artroplasthy, without complications. Valgus subtrochanteric osteotomies can be indicated for the treatment of trochanteric treatment of pseudoarthroses, with good final results for bone union, avoiding the need for total hip artroplasthy and maintaining biological fixation, as well as reestablishing the mechanical and anatomical axis of the affected limb.

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

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.

Healing of osteotomy sites applying either piezosurgery or two conventional saw blades: a pilot study in rabbits.

Science.gov (United States)

Ma, Li; Stübinger, Stefan; Liu, Xi Ling; Schneider, Urs A; Lang, Niklaus P

2013-08-01

The purpose of this study was to compare bone healing of experimental osteotomies applying either piezosurgery or two different oscillating saw blades in a rabbit model. The 16 rabbits were randomly assigned into four groups to comply with observation periods of one, two, three and five weeks. In all animals, four osteotomy lines were performed on the left and right nasal bone using a conventional saw blade, a novel saw blade and piezosurgery. All three osteotomy techniques revealed an advanced gap healing starting after one week. The most pronounced new bone formation took place between two and three weeks, whereby piezoelectric surgery revealed a tendency to faster bone formation and remodelling. Yet, there were no significant differences between the three modalities. The use of a novel as well as the piezoelectric bone-cutting instrument revealed advanced bone healing with a favourable surgical performance compared to a traditional saw.

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

International Nuclear Information System (INIS)

Greer, P.

2004-01-01

Full text: Routine quality assurance (QA) of enhanced dynamic wedge (EDW) is usually performed weekly to monthly. Wedge factors are measured with ion-chamber, and profiles usually with diode-arrays such as the Profiler. The use of an electronic portal imaging device (EPID) for these measurements would combine these into a single rapid set-up and measurement. Currently the Varian EPID in standard imaging mode will not acquire integrated images during EDW treatments, and therefore has not been utilised for EDW dosimetry. Modification to image acquisition was made to enable imaging for EDW, and the performance of the EPID for suitability for quality assurance of EDW was investigated. The accuracy of EDW profiles measured with the EPID were assessed by comparison to Profiler measurements. The EPID was positioned at 105 cm to the detector surface, with 4 cm of additional solid water build-up to give total build-up including EPID inherent build-up of 5 cm. Images of EDW fields were acquired with continuous frame-averaging throughout the delivery. Field sizes of 10x10 cm, and 20x20 cm were used for 30 deg and 60 deg wedge angles for both 6 MV and 18 MV x-rays. Profiler measurements of the same fields were made with 5 cm of solid water build-up with 105 cm to the detector. Profiles in the wedged direction along the central axis of the beam were then compared. The reproducibility of the EPID measured profiles was assessed by three measurements made at weekly intervals. The accuracy of EPID measured wedge factors was investigated with the same experimental set-up. Three images of a 10x10 cm open field were acquired, and the mean pixel value in a 9x9 pixel region at the central axis was found. As the pixel value is the average of all acquired frames, this was multiplied by the number of frames to yield an integrated pixel value. This was repeated for three 10x10 cm 60 deg wedge irradiations. The wedge factor measured with the EPID was then compared to routine weekly

Posterior Femoral Single Limb Osteotomy for the Removal of Well-Fixed Modular Femoral Neck Components

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Keith A Fehring

2017-07-01

Full Text Available Modular neck femoral components were introduced to optimize femoral neck anteversion, leg length, offset, and stability in total hip arthroplasty. However, concerns have been raised in recent years regarding early failure of these implants due to corrosion, pseudotumor, as well as fracture of the modular neck. Removing modular neck femoral implants is challenging as removal of the modular femoral neck leaves a proximally coated femoral stem level with the proximal bone of the femoral neck. We describe a posterior femoral single limb osteotomy  (posterior cut of an extended trochanteric osteotomy for the removal of a modular neck femoral component.

Custom-made prefabricated titanium miniplates in Le Fort I osteotomies: principles, procedure and clinical insights.

Science.gov (United States)

Philippe, B

2013-08-01

This paper describes a new type of miniplate system that is designed and custom made during virtual surgery planning based on an individual patient's osteotomy. These miniplates are prefabricated with commercially pure porous titanium using direct metal laser sintering. The principles that guide the conception and production of this new miniplate are presented. The surgical procedure from the stage of virtual surgery planning until the final Le Fort I osteotomy and bone fixation are described using a case example. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

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

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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.

[Z-osteotomy of distal fibula to correct widened ankle mortice after fracture].

Science.gov (United States)

Tao, Xu; Tang, Kanglai; Zhou, Jianbo

2012-07-01

To analyse the clinical outcomes of the Z-osteotomy of the distal fibula to correct widened mortice of the ankle after fracture. Between September 2009 and February 2011, 5 patients (5 feet) with widened ankle mortice after fracture underwent Z-osteotomy. There were 4 males and 1 female, aged from 23 to 58 years (mean, 38 years). At 3 months after operation of internal fixation when function exercises were done, patients got pains. The interval between trauma and operation ranged from 5 to 36 months (mean, 13.2 months). Lateral pressure test showed positive in 2 cases and negative in 3 cases. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was 50.2 +/- 17.3. Primary healing of incision was achieved in all cases. Five patients were followed up 9 to 24 months (mean, 15.6 months). Mild to moderate swelling of the affected limb and anterolateral skin numbness of the ipsilateral dorsal foot occurred, and gradually improved. The clinical exam and radiology showed bone union at 12-15 weeks (mean, 13.5 weeks). Postoperative range of motion of ankle had no significant improvement. AOFAS ankle-hindfoot scores were 76.8 +/- 11.2 at 6 months after operation, and 85.4 +/- 3.2 at last follow-up, showing significant differences when compared with preoperative score (P ankle mortice after fracture; Z-osteotomy can effectively reduce the width of the ankle mortice, increase the stability of ankle joint, and decrease the complication rate.

Laser-based linear and nonlinear guided elastic waves at surfaces (2D) and wedges (1D).

Science.gov (United States)

Hess, Peter; Lomonosov, Alexey M; Mayer, Andreas P

2014-01-01

The characteristic features and applications of linear and nonlinear guided elastic waves propagating along surfaces (2D) and wedges (1D) are discussed. Laser-based excitation, detection, or contact-free analysis of these guided waves with pump-probe methods are reviewed. Determination of material parameters by broadband surface acoustic waves (SAWs) and other applications in nondestructive evaluation (NDE) are considered. The realization of nonlinear SAWs in the form of solitary waves and as shock waves, used for the determination of the fracture strength, is described. The unique properties of dispersion-free wedge waves (WWs) propagating along homogeneous wedges and of dispersive wedge waves observed in the presence of wedge modifications such as tip truncation or coatings are outlined. Theoretical and experimental results on nonlinear wedge waves in isotropic and anisotropic solids are presented. Copyright © 2013 Elsevier B.V. All rights reserved.

Bone grafting with granular biomaterial in segmental maxillary osteotomy: A case report

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Orion Luiz Haas Junior

2016-01-01

Conclusion: This is the first report of bone grafting with a granular biomaterial in segmental maxillary osteotomy. Successful formation of new bone with density greater than that of the surrounding tissue was achieved, preventing pseudarthrosis and postoperative instability.

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...

What factors predict failure 4 to 12 years after periacetabular osteotomy?

DEFF Research Database (Denmark)

Hartig-Andreasen, Charlotte; Troelsen, Anders; Thillemann, Theis Muncholm

2012-01-01

The goal of periacetabular osteotomy (PAO) is to delay or prevent osteoarthritic development in dysplastic hips. However, it is unclear whether the surgical goals are achieved and if so in which patients. This information is essential to select appropriate patients for a durable PAO that achieves...

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.

Can Double Osteotomy Be a Solution for Adult Hallux Valgus Deformity With an Increased Distal Metatarsal Articular Angle?

Science.gov (United States)

Park, Chul Hyun; Cho, Jae Ho; Moon, Jeong Jae; Lee, Woo Chun

2016-01-01

No previous study has reported the results of double metatarsal osteotomy for adult hallux valgus deformity with an increased distal metatarsal articular angle (DMAA). The purpose of the present study was to evaluate the results after double metatarsal osteotomy in adult patients with incongruent hallux valgus deformity. We retrospectively reviewed 16 cases of consecutive first metatarsal double metatarsal osteotomy without lateral soft tissue release in 14 patients with symptomatic hallux valgus associated with an increased DMAA (≥15° after proximal chevron osteotomy on intraoperative radiographs). Clinical results were assessed using the American Orthopaedic Foot and Ankle Society scale and the visual analog scale. The radiographic results were assessed over time, and changes in the DMAA and the relative length of the first metatarsal were assessed by measuring each value preoperatively and at the last follow-up visit. The American Orthopaedic Foot and Ankle Society and visual analog scale scores were significantly improved after surgery. The hallux valgus angle and intermetatarsal angle were stabilized >3 months after surgery. The sesamoid position did not increase significantly beyond the immediate postoperative period. The mean DMAA was corrected from 21.6° (range 15° to 29°) preoperatively to 11.1° (range -2° to 17°) at the last follow-up visit. The mean amount of shortening of the first metatarsal after surgery was 5.5 (range 4 to 7) mm. In conclusion, double metatarsal osteotomy without lateral soft tissue release in adult hallux valgus deformity results in high postoperative recurrence and complication rates. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Proximal fibular osteotomy: a new surgery for pain relief and improvement of joint function in patients with knee osteoarthritis.

Science.gov (United States)

Wang, Xiaohu; Wei, Lei; Lv, Zhi; Zhao, Bin; Duan, Zhiqing; Wu, Wenjin; Zhang, Bin; Wei, Xiaochun

2017-02-01

Objective To explore the effects of proximal fibular osteotomy as a new surgery for pain relief and improvement of medial joint space and function in patients with knee osteoarthritis. Methods From January 2015 to May 2015, 47 patients who underwent proximal fibular osteotomy for medial compartment osteoarthritis were retrospectively followed up. Preoperative and postoperative weight-bearing and whole lower extremity radiographs were obtained to analyse the alignment of the lower extremity and ratio of the knee joint space (medial/lateral compartment). Knee pain was assessed using a visual analogue scale, and knee ambulation activities were evaluated using the American Knee Society score preoperatively and postoperatively. Results Medial pain relief was observed in almost all patients after proximal fibular osteotomy. Most patients exhibited improved walking postoperatively. Weight-bearing lower extremity radiographs showed an average increase in the postoperative medial knee joint space. Additionally, obvious correction of alignment was observed in the whole lower extremity radiographs in 8 of 47 patients. Conclusions The present study demonstrates that proximal fibular osteotomy effectively relieves pain and improves joint function in patients with medial compartment osteoarthritis at a mean of 13.38 months postoperatively.

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.

Planning corrective osteotomy of the femoral bone using three-dimensional modeling. Part II

Directory of Open Access Journals (Sweden)

Vladimir E. Baskov

2017-10-01

Full Text Available Introduction. Three-dimensional (3D modeling and prototyping are increasingly being used in various branches of surgery for planning and performing surgical interventions. In orthopedics, this technology was first used in 1990 for performing knee-joint surgery. This was followed by the development of protocols for creating and applying individual patterns for navigation in the surgical interventions for various bones. Aim. The study aimed to develop a new 3D method for planning and performing corrective osteotomy of the femoral bone using an individual pattern and to identify the advantages of the proposed method in comparison with the standard method of planning and performing surgical intervention. Materials and methods. A new method for planning and performing corrective osteotomy of the femoral bone in children with various pathologies of the hip joint is presented. The outcomes of planning and performing corrective osteotomy of the femoral bone in 27 patients aged 5 to 18 years (32 hip joints with congenital and acquired deformity of the femoral bone were analyzed. Conclusion. The use of computer 3D modeling for planning and implementing corrective interventions on the femoral bone improves the treatment results owing to an almost perfect performance accuracy achieved by the minimization of possible human errors reduction in the surgery duration; and reduction in the radiation exposure for the patient.

Guided Modern Endodontic Surgery: A Novel Approach for Guided Osteotomy and Root Resection.

Science.gov (United States)

Strbac, Georg D; Schnappauf, Albrecht; Giannis, Katharina; Moritz, Andreas; Ulm, Christian

2017-03-01

Continuous improvements in techniques, instruments, and materials have established modern endodontic microsurgery as a state-of-the-art treatment method. The purpose of this approach was to introduce a new surgical endodontic technique by using a three-dimensional printed template for guided osteotomy and root resection. A 38-year-old patient was diagnosed with periapical lesions of teeth #3 and #4 and extruded gutta-percha material. Three-dimensional radiographic and optical scan files were imported into surgical planning software designed for guided implant surgery. Within the adapted software program the periapical lesions and the extruded gutta-percha were visualized and marked. With the aid of virtually positioned surgical pins and piezoelectric instruments, the osteotomy size, the apical resection level, and the bevel angle were defined before treatment. Three-dimensional surgical templates for each tooth were designed within the software program for a guided treatment approach. This approach comprised the treatment of periapical lesions of teeth #3 and #4 with root-end fillings and the detection and complete removal of the extruded gutta-percha material without perforation of sinus membrane. There were no postoperative complications, and clinical and radiologic assessments verified complete healing of the teeth. The guided microsurgical endodontic treatment presented appears to be a viable technique that allows for predefined osteotomies and root resections. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The synthesis and adsorption properties of some carbohydrate-terminated dendrimer wedges

International Nuclear Information System (INIS)

Ainsworth, Richard L.

1997-01-01

A range of dendritic molecules that are designed to bind to a cotton surface has been synthesised. The architecture of the molecules allows the location of various functional, property modifying units at the focus and the attachment of recognition groups at the periphery of a dendritic molecule with wedge topology. The synthesis and characterisation of dendrimer wedges up to the second generation using a divergent approach has been performed. These wedges are readily built up using a simple and efficient stepwise pathway from the central core, and surface recognising species are subsequently attached to the molecule utilising procedures developed in conjunction with Unilever Research Laboratories. Work has been carried out to assess their adsorption onto a cotton surface and the postulated adsorption mechanism is discussed. (author)

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.

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

Chronology and palaeoenvironmental implications of the ice-wedge pseudomorphs and composite-wedge casts on the Magdalen Islands (eastern Canada)

DEFF Research Database (Denmark)

Remillard, A.M.; Hetu, B.; Bernatchez, P.

2015-01-01

to the former presence of permafrost under periglacial conditions. These features truncate Carboniferous sandstone or Last Glacial Maximum (LGM) glacial and glaciomarine diamicts, both overlain by subtidal or coastal units. Six optically stimulated luminescence (OSL) and four radiocarbon ages were obtained from......The Magdalen Islands are a valuable terrestrial record, evidencing the complex glacial and periglacial history of the Gulf of St. Lawrence. Thirteen structures interpreted as ice-wedge pseudomorphs or composite-wedge casts were observed at four sites on the southern Magdalen Islands and testify...... both host and infilled sedimentary units. These ages provide the first absolute chronological data on these structures, shedding new light on the relationships between glacial and periglacial phases. Our chronostratigraphic data suggest that, after the deglaciation and the emersion of the archipelago...

Operative treatment of hallux valgus – the effect of three osteotomy types on the first metatarsal, hallux valgus and metatarsal distal articulation angles

Directory of Open Access Journals (Sweden)

Andrej Prlja

2007-11-01

Full Text Available Background: Modern approach to hallux valgus deformations enables not only the stage treatment considering the magnitude of the deformity but also the objective evaluation of the results.We investigated the influence of the three most commonly used osteotomies on three most common demonstrative factors, especially proximal osteotomy on the distal metatasal articulation angle.Methods: Three groups were created regarding the magnitude of the deformation. X rays of 15 corrections in each group were reviewed (45 cases, 34 women, 2 men. Each group was treated with only one of the three osteotomies: distal chevron osteotomy (Ch, distal chevron osteotomy with medial edge (ChM and proximal osteotomy (POT. The effect on the three most comonly used demonstrative factors were noted: first intermetatarsal angle (IM, hallux valgus angle (HV, distal metatarsal articulation angle (DMAA. The age and the demonstrative factors were compared pre- and postoperative, in and between the groups.Results: The correct, graded selection of the patients for the treatment was confirmed and false negative results excluded. Preoperative values of HV and DMAA are significantely different between three groups (p < 0.001 while IM are not (p = 0.118. Postoperative values of the HV and IM are significantely lower in all three groups (p < 0.001. DMAA is statisticaly different (positive postoperatively in the ChM group (p < 0.001 but not in the Ch and POT groups (P = 0.398; p = 0.456.Conclusions: Modern approach on hallux valgus deformations enables stage treatment and objective evaluation of the results what is demonstrated by the effect of the osteotomies on the demonstrative factors. Further investigations of the factors not yet considered or even unknown are also possible as shown on the example of the difference between the expected and measured effect of POT on DMAA.

Rainfall induced groundwater mound in wedge-shaped promontories: The Strack-Chernyshov model revisited

Science.gov (United States)

Kacimov, A. R.; Kayumov, I. R.; Al-Maktoumi, A.

2016-11-01

An analytical solution to the Poisson equation governing Strack's discharge potential (squared thickness of a saturated zone in an unconfined aquifer) is obtained in a wedge-shaped domain with given head boundary conditions on the wedge sides (specified water level in an open water body around a porous promontory). The discharge vector components, maximum elevation of the water table in promontory vertical cross-sections, quantity of groundwater seeping through segments of the wedge sides, the volume of fresh groundwater in the mound are found. For acute angles, the solution to the problem is non-unique and specification of the behaviour at infinity is needed. A ;basic; solution is distinguished, which minimizes the water table height above a horizontal bedrock. MODFLOW simulations are carried out in a finite triangular island and compare solutions with a constant-head, no-flow and ;basic; boundary condition on one side of the triangle. Far from the tip of an infinite-size promontory one has to be cautious with truncation of the simulated flow domains and imposing corresponding boundary conditions. For a right and obtuse wedge angles, there are no positive solutions for the case of constant accretion on the water table. In a particular case of a confined rigid wedge-shaped aquifer and incompressible fluid, from an explicit solution to the Laplace equation for the hydraulic head with arbitrary time-space varying boundary conditions along the promontory rays, essentially 2-D transient Darcian flows within the wedge are computed. They illustrate that surface water waves on the promontory boundaries can generate strong Darcian waves inside the porous wedge. Evaporation from the water table and sea-water intruded interface (rather than a horizontal bed) are straightforward generalizations for the Poissonian Strack potential.

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.

Minimally invasive (MIS) Tönnis osteotomy- A technical annotation and review of short term results.

Science.gov (United States)

Balakumar, Balasubramanian; Racy, Malek; Madan, Sanjeev

2018-03-01

We detail a modified single incision approach to perform the Tonnis triple pelvic osteotomy by a minimally invasive approach. 12 children underwent minimally invasive Tonnis Osteotomy. There were five boys and seven girls in this study group. Average age was 11 years (9-15 years) at the time of surgery. Mean follow-up was 20.5 months (13-39 months). The average preoperative Antero-Posterior (AP) Centre Edge (CE) angle was -8.8° (-38.6°-18°), the average post-operative AP CE angle was 29.7° (25.1°-43.7°). The average preoperative lateral CE angle was -4.7° (-16°-0°), the average postoperative Lateral CE angle was 28.5° (21.3°-37.4°). The Sharp's angle before and after surgery were 55.7° (51.3°-66°) and 32.4° (16.1°-40.1°) respectively. The mean Tönnis angle before and after the osteotomy were 28.86° (19.7°-43.4°) and 6.3° (0.5°-9.4°) respectively. There was one major complication with sciatic nerve palsy which is in the recovery phase on followup and six minor complications including two cases of transient lateral femoral cutaneous nerve injury, two cases of ischial non-union, over granulation of the wound in one case, and metalwork irritation in one case. We have described a minimally invasive Tonnis osteotomy as a viable option based on our results. This technique is recommended for those who are conversant with the traditional pelvicosteotomies.

Cost, operation and hospitalization times in distraction osteogenesis versus sagittal split osteotomy

NARCIS (Netherlands)

van Strijen, P. J.; Breuning, K. H.; Becking, A. G.; Perdijk, F. B. T.; Tuinzing, D. B.

2003-01-01

Distraction osteogenesis in 'common' surgical orthodontics is mentioned as an alternative for conventional sagittal split osteotomy. After a 'learning curve' in the surgical skills of distraction, the two techniques can be compared concerning time and cost aspects. Forty-seven patients (male n=28,

A Modified Technique of Fixation for Proximal Femoral Valgus Osteotomy in Abnormal Bone: A Report of Two Cases

Directory of Open Access Journals (Sweden)

Logheswaren S

2017-07-01

Full Text Available The ideal size of intramedullary device to fix corrective osteotomy of proximal femur in abnormal bone in children and small patients may not be easily available. We report the successful use of Rush rod in combination with multiple Kirschner wires to fix the corrective osteotomy of coxa vara and shepherd crook deformity in two patients with osteogenesis imperfecta and fibrous dysplasia. The union was achieved on time, neck shaft angle and rotation were maintained.

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

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.

Varus femoral osteotomy improves sphericity of the femoral head in older children with severe form of Legg-Calvé-Perthes disease.

Science.gov (United States)

Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

2012-09-01

In the Norwegian prospective study on Legg-Calvé-Perthes disease (LCPD), we found varus femoral osteotomy gave better femoral head sphericity at a mean of 5 years postoperative than physiotherapy in children older than 6.0 years at diagnosis with femoral head necrosis of more than 50%. That study did not include separate analyses for hips with 100% necrosis and those with a percentage of necrosis between 50% and 100%. We asked whether (1) femoral osteotomy improves femoral head sphericity at followup in all patients with more than 50% femoral head necrosis or in selected groups only and (2) there is a critical age between 6.0 and 10.0 years over which femoral osteotomy does not improve the prognosis. We treated 70 patients with unilateral LCPD, age at diagnosis of more than 6.0 years, and femoral head necrosis of more than 50% with varus femoral osteotomy between 1996 and 2000. We classified necrosis using the Catterall classification. We established a control group of 51 similar children who received physiotherapy. At the 5-year followup visit, the hips were graded according to femoral head shape: spherical, ovoid, or flat. At 5-year followup, there was no difference between the treatment groups in radiographic outcome in Catterall Group 3 hips. In Catterall Group 4 hips, femoral head sphericity was better in the osteotomy group, with flat femoral heads in 14% compared to 75% after physiotherapy. The same trend toward better head sphericity occurred when the lateral pillar classification was used. In children aged 6.0 to 10.0 years, in whom the whole femoral head is affected, femoral head sphericity 5 years after femoral osteotomy was better than that after physiotherapy.

Monte Carlo simulation of the Varian Clinac 600C accelerator using dynamic wedges

International Nuclear Information System (INIS)

Moreno, S.; Chaves, A.; Lopes, M.C.; Peralta, L.; Universidade de Lisboa

2004-01-01

The advent of linear accelerators (linac) with computer-controlled dynamic collimation systems and functional and anatomical imaging techniques allowed a more exact delimitation and localisation of the target volume. These advanced treatment techniques inevitably increase the complexity level of dose calculation because of the introduction of the temporal variable. On account of this, it is mandatory the usage of more accurate modelling techniques of the collimator components, as it is the case of Monte Carlo (MC) simulation, which has created an enormous interest in research and clinical practice. Because the patients bodies are not homogenous nor are their body surfaces plane and regular, the dose distribution may differ significantly from the standard distribution from the linac calibration. It is in the treatment planning systems, which include algorithms that are usually measured in homogeneous water phantoms specific for each correction that the dose distributions from each case are obtained. In a real treatment, exception made to superficial lesions, two or more radiation fields are used in order to obtain the recommended dose distributions. The simplest arrangement is made from two parallel and opposed fields that originate a homogeneous dose distribution in almost all the irradiated volume. The available resources are, for example, different types of energies and of radiation, the application of bolus, the protection of healthy structures, the usage of wedged filters and the application of dynamic wedges. A virtual or dynamic wedge, modelled through the movement of one of the jaws, when compared with a set of physical wedges offers an alternative calculation method of an arbitrary number of wedged fields, instead of the four traditional fields of 15 deg, 30 deg, 45 deg and 60 deg angle and obtained with physical wedges. The goal of this work consists in the study of the application of dynamic wedges in tailoring the radiation field by the Varian Clinac 600

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.

Axial loading screw fixation for chevron type osteotomies of the distal first metatarsal: a retrospective outcomes analysis.

Science.gov (United States)

Murphy, Ryan M; Fallat, Lawrence M; Kish, John P

2014-01-01

The distal chevron osteotomy is a widely accepted technique for the treatment of hallux abductovalgus deformity. Although the osteotomy is considered to be stable, displacements of the capital fragment has been described. We propose a new method for fixation of the osteotomy involving the axial loading screw (ALS) used in addition to single screw fixation. We believe this method will provide a more mechanically stable construct. We reviewed the charts of 46 patients in whom 52 feet underwent a distal chevron osteotomy that was fixated with either 1 screw or 2 screws that included the ALS. We hypothesized that the ALS group would have fewer displacements and would heal more quickly than the single screw fixation group. We found that the group with ALS fixation had healed at a mean of 6.5 weeks and that the group with single screw fixation had healed at 9.53 weeks (p = .001). Also, 8 cases occurred of displacement of the capital fragment in the single screw, control group compared with 2 cases of displacement in the ALS group. However, this finding was not statistically significant. The addition of the ALS to single screw fixation allowed the patients to heal approximately 3 weeks earlier than single screw fixation alone. The ALS is a fixation option for the surgeon to consider when osseous correction of hallux abducto valgus is performed. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

[Double Osteotomy of the First Metatarsal for Treatment of Juvenile Hallux Valgus Deformity - Our Experience].

Science.gov (United States)

Jochymek, J; Peterková, T

2016-01-01

The aim of the study was to evaluate the mid-term results in a group of selected patients undergoing corrective surgery for juvenile hallux valgus, using double osteotomy of the first metatarsal. The group included eight patients, seven girls and one boy, with a more severe form of this deformity treated by double osteotomy of the first metatarsal between 2010 and 2013. The indication for corrective surgery was serious pain when walking; all patients had previously undergone conservative treatment with no effect. All patients had pre-operative clinical examination, the affected foot was X-rayed with the patient standing and radiographic assessments of the intermetatarsal and hallux valgus angles were made. The evaluation of treatment outcomes was based on the scoring system of the American Orthopaedic Foot and Ankle Society (AOFAS) and X-ray images of the foot. The average follow-up was 37 months. Post-operatively, none of the patients reported pain while walking, only two of them experienced pain during sports activities. The average post-operative AOFAS score was 92 points. Both the intermetatarsal angle and the hallux valgus angle improved after surgery in all patients, with two reporting only mild hallux valgus deformity. One patient showed postoperative restriction of motion at the first metatarsophalangeal joint. This was the only complication recorded in association with the surgery. Almost all authors dealing with the treatment of hallux valgus deformity primarily prefer conservative therapy. However, this treatment is usually not very effective in severe forms of the disorder. Surgical management is indicated in symptomatic patients or in those with severe juvenile hallux valgus deformity. In paediatric patients it is necessary to respect the presence of an epiphyseal growth plate in the first proximal metatarsal and therefore it is often preferred to use distal first metatarsal osteotomy. At our department, Mitchell's osteotomy for hallux valgus deformity

Risk factors affecting somatosensory function after sagittal split osteotomy

DEFF Research Database (Denmark)

Thygesen, Torben Henrik; Jensen, Allan Bardow; Helleberg, M

2008-01-01

Purpose The aim of this study was to evaluate potential individual and intraoperative risk factors associated with bilateral sagittal split osteotomy (BSSO) and to correlate the findings with postoperative changes in somatosensory function. Patients and Methods A total of 18 men and 29 women (mean...... and free dissection of the inferior alveolar nerve during BSSO increased self-reported changes in lower lip sensation and lower lip tactile threshold after BSSO (P discrimination (P

Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

International Nuclear Information System (INIS)

Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo; Kim, Ah Young; Lee, Hyun Ju; Song, Chi Sung; Choi, Byung Ihn

2000-01-01

To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

Computer assistance in femoral derotation osteotomy: a bottom-up approach

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Auer Christoph

2016-09-01

Full Text Available Severe gait abnormalities in patients with cerebral palsy are often treated by correction osteotomy. The established procedure of femoral derotation osteotomy (FDO has proven effective to realign femur anteversion. Nevertheless, studies have revealed that therapy outcome is subject to substantial inter-patient variability and systematic loss of correction. Our previous work suggests that practical limitations in FDO may significantly contribute to this effect. In this work, we propose a novel computer assisted measurement system to support FDO with objective measurement (desired accuracy: ∼ ± 3° and continuous monitoring of derotation. A prototype system based on the clinically emerging electromagnetic tracking technology is demonstrated which incorporates technical and operational considerations to enable continuous measurement in OR conditions while preserving the conventional workflow without disruptions. In phantom studies, the achieved measurement accuracy (standard error ≅±1.6∘$\\cong\\pm 1.6{}^{\\circ}$ proved high potential and may hugely benefit the quality of surgical execution. Currently, the prototype system is assessed under OR conditions in an in-vivo study with CP patients. Early experience shows high appreciation among surgeons and good potential for future application.

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

Biomechanical Analysis of Cuboid Osteotomy Lateral Column Lengthening for Stage II B Adult-Acquired Flatfoot Deformity: A Cadaveric Study

OpenAIRE

Zhou, Haichao; Ren, Haoyang; Li, Chunguang; Xia, Jiang; Yu, Guangrong; Yang, Yunfeng

2017-01-01

Purpose. To investigate the effect of cuboid osteotomy lateral column lengthening (LCL) for the correction of stage II B adult-acquired flatfoot deformity in cadaver. Methods. Six cadaver specimens were loaded to 350?N. Flatfoot models were established and each was evaluated radiographically and pedobarographically in the following conditions: (1) intact foot, (2) flatfoot, and (3) cuboid osteotomy LCL (2, 3, 4, and 5?mm). Results. Compared with the flatfoot model, the LCLs showed significant...

Assessment of pterygomaxillary separation in Le Fort I Osteotomy in class III patients.

Science.gov (United States)

Ueki, Koichiro; Hashiba, Yukari; Marukawa, Kohei; Okabe, Katsuhiko; Alam, Shamiul; Nakagawa, Kiyomasa; Yamamoto, Etsuhide

2009-04-01

To examine the separation of the pterygomaxillary region at the posterior nasal spine level after Le Fort I osteotomy in Class III patients. The study group consisted of 37 Japanese patients with mandibular prognathism and asymmetry, with maxillary retrognathism or asymmetry. A total of 74 sides were examined. Le Fort I osteotomy was performed without a pterygoid osteotome, with an ultrasonic curette used to remove interference at the pterygomaxillary region. Postoperative computed tomography (CT) was analyzed for all patients. The separation of the pterygomaxillary region and the location of the descending palatine artery were assessed. Although acceptable separation between the maxilla and pterygoid plates was achieved in all patients, an exact separation of the pterygomaxillary junction at the posterior nasal spine level was found in only 18 of 74 sides (24%). In 29 of 74 sides (39.2%), the separation occurred anterior to the descending palatine artery. In 29 of 74 sides (39.2%), complete separation between the maxilla and lateral and/or medial pterygoid plate was not achieved, but lower level separation of the maxilla and pterygoid plate was always complete. The maxillary segments could be moved to the postoperative ideal position in all cases. Le Fort I osteotomy without an osteotome does not always induce an exact separation at the pterygomaxillary junction at the posterior nasal spine level, but the ultrasonic bone curette can remove the interference between maxillary segment and pterygoid plates more safely.

Use of steroids in rhinoplasty with lateral osteotomies for reducing post operative oedema

International Nuclear Information System (INIS)

Sanober, A.; Rashid, M.; Khan, M.I.; Rehman, S.U.; Fatima, S.; Hussain, A.

2018-01-01

Postoperative periorbital edema is a commonly encountered side effect of rhinoplasties in which lateral osteotomies have been incorporated. It dissatisfies the surgeon as well as the patient. Osteotomies are done at the end of all soft tissue manipulation to reduce the development of edema. The aim of this study was to determine the efficacy of intravenous dexamethasone in reducing edema in patients who undergo rhinoplasty with lateral osteotomies. Methods A Prospective randomized controlled trial was done at department of plastic and reconstructive surgery, Shifa International Hospital Islamabad. Sixty patients age between 16- 55 requiring open rhinoplasty were taken for this study and divided in two groups. One group received dexamethasone 8mg intravenously peroperatively and second dose 4 hours postoperatively. The second group did not receive anything. Both groups were assessed on first post operative day and 7th day for periorbital edema. Result The overall decrease in edema in patients who received steroid was by 50% while in control group was 33.3%. By the 7th day control group 13.3% patients had grade III edema as compared to 3.33% in steroid group. Chi test was applied and p value of 0.0289 was obtained which was found to be statistically very significant. Conclusion Dexamethasone used in minimal dosage showed significant advantage in reducing periorbital edema after rhinoplasty with no evidence of any side effects secondary to steroid administration. (author)

Biomechanical comparison between titanium and cobalt chromium rods used in a pedicle subtraction osteotomy model

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Kalpit N. Shah

2018-03-01

Full Text Available Instrumentation failure is a common complication following complex spinal reconstruction and deformity correction. Rod fracture is the most frequent mode of hardware failure and often occurs at or near a 3-column osteotomy site. Titanium (Ti rods are commonly utilized for spinal fixations, however, theoretically stiffer materials, such as cobalt-chrome (CoCr rods are also available. Despite ongoing use in clinical practice, there is little biomechanical evidence that compares the construct ability to withstand fatigue stress for Ti and Co-Cr rods. Six models using 2 polyethylene blocks each were used to simulate a pedicle subtraction osteotomy. Within each block 6.0×45 mm polyaxial screws were placed and connected to another block using either two 6.0×100 mm Ti (3 models or CoCr rods (3 models. The rods were bent to 40° using a French bender and were secured to the screws to give a vertical height of 1.5 cm between the blocks. The blocks were fatigue tested with 700N at 4 Hz until failure. The average number of cycles to failure for the Ti rod models was 12840 while the CoCr rod models failed at a significantly higher, 58351 cycles (P=0.003. All Ti models experienced rod fracture as the mode of failure. Two out of the three CoCr models had rod fractures while the last sample failed via screw fracture at the screw-tulip junction. The risk of rod failure is substantial in the setting of long segment spinal arthrodesis and corrective osteotomy. Efforts to increase the mechanical strength of posterior constructs may reduce the occurrence of this complication. Utilizing CoCr rods in patients with pedicle subtraction osteotomy may reduce the rate of device failure during maturation of the posterior fusion mass and limit the need for supplemental anterior column support.

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.

Results of Chiari pelvic osteotomy for acetabular dysplasia in adults; Association with bone scintigraphic findings

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Nobuo; Ozono, Kenji; Sugano, Nobuhiko; Takaoka, Kunio; Ono, Hiroo (Osaka Univ. (Japan). Faculty of Medicine)

1993-02-01

In an attempt to determine indications of Chiari pelvic osteotomy in acetabular dysplasia, postoperative outcome of hip joint (64 joints) was examined on the basis of findings of bone scintigraphy. The subjects were 61 patients with osteoarthrosis of hip joint who underwent preoperative bone scintigraphy. The follow-up period ranged from 2 years to 9 years and 7 months with a mean of 4 years and 9 months. According to X-ray findings, 37 osteoarthrosis joints were staged as early and 27 as progressive. Preoperative bone scintigraphic findings fell into three: (I) normal or slight hot type (33 joints), (II) hot type at the weighting part (16 joints), and (III) double hot type in the weighting part and inside part (15 joints). None of the patients had severe surgical complications such as deep-seated infection, neuroparalysis and pseudojoint. According to the clinical staging for hip joint function, 7 (47%) of 64 joints were judged as poor after osteotomy, belonging to type III. Deterioration of osteoarthrosis was seen in 11 joints (41%) on X-ray films. Of these, 9 had type III. In conclusion, Chiari pelvic osteotomy should not be indicated when type III is shown on bone scintigrams. (N.K.).

The effects of Mandibular Osteotomy on articulation and resonance

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Delsa Geffen

1978-11-01

Full Text Available Pre- and post-operative speech samples were studied in nine adult cases who received Mandibular Osteotomy. Lateral cephalograms were taken during sustained production of selected sounds and trained listeners judged recordings. In most cases there was an improvement in the general quality of the speech. Considering that the functional  relationships between the speech organs had altered, it would appear that some form of adaptation by the speaker had in fact taken place.

Modified Chevron osteotomy for hallux valgus deformity in female athletes. A 2-year follow-up study.

Science.gov (United States)

Giotis, Dimitrios; Paschos, Nikolaos K; Zampeli, Franceska; Giannoulis, Dionisios; Gantsos, Apostolos; Mantellos, George

2016-09-01

Hallux valgus is an increasingly common deformity in young female athletes that constricts their daily athletic activities and influences foot cosmesis. The aim of this study was to evaluate the outcome of modified Chevron osteotomy for hallux valgus deformity in this specific population. Forty-two cases of modified Chevron osteotomies were carried out in 33 patients with mild to moderate hallux valgus deformity. Each participant was evaluated for AOFAS score, pain, range of motion, cosmetic and radiological outcome. Mean AOFAS score improved to 96.3 (phallux valgus deformity in young female athletes, with excellent clinical outcome. Copyright © 2015 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Partial maxillary osteotomy following an unsuccessful forced eruption of an impacted maxillary canine: 10 year follow-up. Review and case report

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Edela Puricelli

2012-12-01

Full Text Available The maxillary canines are amongst the most frequently impacted teeth, second only to the third molars. Several conservative orthodontic and surgical techniques are available to position the teeth properly in the dental arch, even in severe cases. However, when an extraction is necessary, it often leaves a critical alveolar defect of difficult management. The authors present the technique of Partial Maxillary Osteotomy, in which a dento-alveolar segment is moved mesially, hence closing the remaining space, allowing for the formation of healthy periodontium and resulting in an adequate functional and aesthetic outcome. A case report is presented with a 10 year follow-up, proving the technique's stability in the long term.

How does ulnar shortening osteotomy influence morphologic changes in the triangular fibrocartilage complex?

Science.gov (United States)

Yamanaka, Yoshiaki; Nakamura, Toshiyasu; Sato, Kazuki; Toyama, Yoshiaki

2014-11-01

Ulnar shortening osteotomy often is indicated for treatment of injuries to the triangular fibrocartilage complex (TFCC). However, the effect of ulnar shortening osteotomy on the changes in shape of the TFCC is unclear. In our study, quantitative evaluations were performed using MRI to clarify the effect of ulnar shortening on triangular fibrocartilage (TFC) thickness attributable to disc regeneration of the TFC and TFC angle attributable to the suspension effect of ulnar shortening on the TFC. The purposes of this study were (1) to compare preoperative and postoperative TFC thickness and TFC angle on MR images to quantitatively evaluate the effect of ulnar shortening osteotomy on disc regeneration and the suspension effect on the TFC; and (2) to assess whether changes in TFC thickness and TFC angle correlated with the Mayo wrist score. Between 1995 and 2008, 256 patients underwent ulnar shortening osteotomy for TFCC injuries. The minimum followup was 24 months (mean, 51 months; range, 24-210 months). A total of 79 patients (31%) with complete followup including preoperative and postoperative MR images and the Mayo wrist score was included in this retrospective study. Evaluation of the postoperative MR images and the Mayo wrist score were performed at the final followup. The remaining 177 patients did not undergo postoperative MRI, or they had a previous fracture, large tears of the disc proper, or were lost to followup. Two orthopaedists, one of whom performed the surgeries, measured the TFC thickness and the TFC angle on coronal MR images before and after surgery for each patient. Correlations of the percent change in the TFC thickness and the magnitude of TFC angle change with age, sex, postoperative MR images, extent of ulnar shortening, preoperative ulnar variance, and postoperative Mayo wrist score were assessed. Stepwise regression analysis showed a correlation between the percent change in TFC thickness and preoperative ulnar variance (R2=0.21; β=-0.33; 95

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

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.

Comparison of Clinical Outcomes of Scarf and Chevron Osteotomies and the McBride Procedure in the Treatment of Hallux Valgus Deformity

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Mohammad Fakoor

2014-03-01

Full Text Available Background:   Hallux valgus deformity is a common chronic problem in middle age and elderly. Different surgical procedures have been introduced so far with their proposed indications for each. This study aimed to compare three   current procedures namely Chevron osteotomy, Scarf osteotomy and McBride technique.     Methods:   In this study, 44 patients were included from 2010 to 2013. All patients had been undergone one of the three current procedures including Chevron, Scarf or McBride techniques. Preoperative and follow-up radiographies     were evaluated in terms of hallux valgus and intermetatarsal angles. Foot Ankle Disability Index was filled to assess the functional. A Visual Analogue Scale evaluated pain. Also, satisfaction, aesthetic and the rate of recurrence were evaluated. Results:   Functional score, aesthetic and satisfaction level were higher in Scarf technique rather than Chevron and McBride techniques. Also, pain score and recurrence rate were lower in Scarf Technique rather the other two techniques.     Conclusions:   With respect to better results with Scarf osteotomy in this study, we recommend Scarf osteotomy as   a first choice for treatment of moderate hallux valgus deformity.

Evaluation of off-axis wedge correction factor using diode dosimeters for estimation of delivered dose in external radiotherapy

International Nuclear Information System (INIS)

Allahverdi, Mahmoud; Shirazi, Alireza; Geraily, Ghazale; Mohammadkarim, Alireza; Esfehani, Mahbod; Nedaie, Hasanali

2012-01-01

An in vivo dosimetry system, using p-type diode dosimeters, was characterized for clinical applications of treatment machines ranging in megavoltage energies. This paper investigates two different models of diodes for externally wedged beams and explains a new algorithm for the calculation of the target dose at various tissue depths in external radiotherapy. The values of off-axis wedge correction factors were determined at two different positions in the wedged (toward the thick and thin edges) and in the non-wedged directions on entrance and exit surfaces of a polystyrene phantom in 60 Co and 6 MV photon beams. Depth transmission was defined on the entrance and exit surfaces to obtain the off-axis wedge correction factor at any depth. As the sensitivity of the diodes depends on physical characteristics (field size, source-skin distance (SSD), thickness, backscatter), correction factors were applied to the diode reading when measuring conditions different from calibration situations. The results indicate that needful correction factors for 60 Co wedged photons are usually larger than those for 6 MV wedged photon beams. In vivo dosimetry performed with the proposed algorithms at externally wedged beams has negligible probable errors (less than 0.5%) and is a reliable method for patient dose control. (author)

Evaluation of off-axis wedge correction factor using diode dosimeters for estimation of delivered dose in external radiotherapy

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Mahmoud Allahverdi

2012-01-01

Full Text Available An in vivo dosimetry system, using p-type diode dosimeters, was characterized for clinical applications of treatment machines ranging in megavoltage energies. This paper investigates two different models of diodes for externally wedged beams and explains a new algorithm for the calculation of the target dose at various tissue depths in external radiotherapy. The values of off-axis wedge correction factors were determined at two different positions in the wedged (toward the thick and thin edges and in the non-wedged directions on entrance and exit surfaces of a polystyrene phantom in 60 Co and 6 MV photon beams. Depth transmission was defined on the entrance and exit surfaces to obtain the off-axis wedge correction factor at any depth. As the sensitivity of the diodes depends on physical characteristics [field size, source-skin distance (SSD, thickness, backscatter], correction factors were applied to the diode reading when measuring conditions different from calibration situations . The results indicate that needful correction factors for 60 Co wedged photons are usually larger than those for 6 MV wedged photon beams. In vivo dosimetry performed with the proposed algorithms at externally wedged beams has negligible probable errors (less than 0.5% and is a reliable method for patient dose control.

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)

Unstable recent intracapsular femoral neck fractures in young adults: Osteosynthesis and primary valgus osteotomy using broad dynamic compression plate

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Singh M

2008-01-01

Full Text Available Background: Displaced intracapsular femoral neck fractures continue to be a difficult problem to treat. Various treatment modalities and their modifications have been proposed to improve the outcome. Osteosynthesis and primary valgus angulation osteotomy is one of them. Technique and outcome in a consecutive series of recent intracapsular femoral neck fractures in young adults, from a single center, is presented. Materials and Methods: Fifty-five patients of recent (< 3 weeks old displaced intracapsular fracture neck femur (Garden III and IV, Pauwels III, with or without comminution in the age group 20-50 years (mean 35.4±10.4 years were subjected to osteosynthesis and primary valgus intertrochanteric osteotomy using contoured broad dynamic compression plate (DCP. The patients were followed up from two to six years (mean 4.6 years. Results: Fifty-one fractures united by six months of the index procedure (92.7% union range. Avascular necrosis (AVN developed in six patients (11%. The other complications were shortening (six, coxa vara (two, infection (two and delayed union at osteotomy site (one. Excellent results were achieved in 48, good/fair in four and poor in three patients. Conclusion: Osteosynthesis with cancellous screw and primary valgus intertrochanteric osteotomy stabilized by a contoured broad DCP is a simple, easy to perform, biological treatment. Failure in a particular case can be treated with any appropriate second procedure. Level of Evidence: IV

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

Complete Cranial Iliac Osteotomy to Approach the Lumbosacral Foramen

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Barbara Dyall

2017-05-01

Full Text Available An approach using a complete cranial iliac osteotomy (CCIO to access the lumbosacral (LS foramen in dogs from lateral was developed using cadavers and applied in a clinical patient with degenerative lumbosacral stenosis (DLSS. The foraminal enlargement in the cadavers and the patient was documented on postoperative CT scans. The preoperative CT scan of the patient showed moderate cranial telescoping of the sacral roof and a moderate central disk protrusion, leading to moderate to severe compression of the cauda equina. In addition, there was lateral spondylosis with consequential stenosis of the right LS foramen. The right L7 nerve had lost its fat attenuation and appeared thickened. After a routine L7S1 dorsal laminectomy with a partial discectomy, a CCIO was performed, providing good access to the LS foramen and the adhesions around the proximal L7 nerve caudoventral to the foramen. The osteotomy was stabilized with a locking plate and a cerclage wire. The dog recovered well from the procedures and after 36 h, the dog walked normally and was discharged from the hospital. Eight and 16 weeks later, the signs of the DLSS had markedly improved. From these data, it can be concluded that the CCIO is a useful approach to the LS foramen and intervertebral disk in selected patients with DLSS, giving good access to the structures around the LS foramen.

Radiographic Outcomes Following Lateral Column Lengthening With a Porous Titanium Wedge.

Science.gov (United States)

Gross, Christopher E; Huh, Jeannie; Gray, Joni; Demetracopoulos, Constantine; Nunley, James A

2015-08-01

Lateral column lengthening (LCL) is commonly utilized in treating stage II posterior tibialis tendon dysfunction. This study aimed to analyze the outcomes of LCL with porous titanium wedges compared to historic controls of iliac crest autograft and allograft. We hypothesized that the use of a porous titanium wedge would have radiographic improvement and union rates similar to those with the use of autograft and allograft in LCL. Between May 2009 and May 2014, 28 feet in 26 patients were treated with LCL using a porous titanium wedge. Of the 26 patients, 9 were males (34.6%). The average age for males was 43 years (range, 17.9-58.7), 48.7 years (range, 21-72.3) for females. Mean follow-up was 14.6 months. Radiographs were examined for correction of the flatfoot deformity and forefoot abduction. All complications were noted. Radiographically, the patients had a significant deformity correction in the anteroposterior talo-first metatarsal angle, talonavicular coverage angle, lateral talo-first metatarsal angle, and calcaneal pitch. All but 1 patient (96%) had bony incorporation of the porous titanium wedge. The average preoperative visual analog scale pain score was 5; all patients but 3 (12%) had improvements in their pain score, with a mean change of 3.4. LCL with porous titanium had low nonunion rates, improved radiographic correction, and pain relief. Level IV, case series. © The Author(s) 2015.

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)

Various bio-mechanical factors affecting heat generation during osteotomy preparation: A systematic review.

Science.gov (United States)

Chauhan, Chirag J; Shah, Darshana N; Sutaria, Foram B

2018-01-01

As implant site preparation and bone are critical precursors to primary healing, thermal and mechanical damage to the bone must be minimized during the preparation of the implant site. Moreover, excessively traumatic surgery can adversely affect the maturation of bone tissue at the bone/implant interface and consequently diminish the predictability of osseointegration. So, this study was carried out to evaluate the various biological and mechanical factors responsible for heat generation during osteotomy site preparation to reduce the same for successful osseointegration of dental implants. A broad search of the dental literature in PubMed added by manual search was performed for articles published between 1992 and December 2015. Various bio-mechanical factors related to dental implant osteotomy preparation such as dental implant drill designs/material/wear, drilling methods, type of irrigation, and bone quality were reviewed. Titles and abstracts were screened and articles which fulfilled the inclusion criteria were selected for a full-text reading. The initial database search yielded 123 titles, of which 59 titles were discarded after reading the titles and abstracts, 30 articles were again excluded based on inclusion and exclusion criteria, and finally 34 articles were selected for data extraction. Many biological and mechanical factors responsible for heat generation were found. Literatures of this review study have indicated that there are various bio-mechanical reasons, which affect the temperature rise during osteotomy and suggest that the amount of heat generation is a multifactorial in nature and it should be minimized for better primary healing of the implant site.

Subjective alveolar nerve function after bilateral sagittal split osteotomy or distraction osteogenesis of mandible

NARCIS (Netherlands)

Baas, E.M.; Horsthuis, R.B.G.; de Lange, J.

2012-01-01

Purpose: The present retrospective cohort study compared the subjective inferior alveolar nerve (IAN) function after distraction osteogenesis (DOG) and bilateral sagittal split osteotomy (BSSO) in mandibular advancement surgery. Materials and Methods: Treatment consisted of correction of a

Subjective Alveolar Nerve Function After Bilateral Sagittal Split Osteotomy or Distraction Osteogenesis of Mandible

NARCIS (Netherlands)

Baas, Erik M.; Horsthuis, Roy B. G.; de Lange, Jan

2012-01-01

Purpose: The present retrospective cohort study compared the subjective inferior alveolar nerve (IAN) function after distraction osteogenesis (DOG) and bilateral sagittal split osteotomy (BSSO) in mandibular advancement surgery. Materials and Methods: Treatment consisted of correction of a

Internal Distraction Osteogenesis With Piezosurgery Oblique Osteotomy of Supraorbital Margin of Frontal Bone for the Treatment of Unilateral Coronal Synostosis.

Science.gov (United States)

Shen, Weimin; Cui, Jie; Chen, Jianbing; Ji, Yi; Kong, Liangliang

2017-05-01

To assess the utility of internal distraction osteogenesis with Piezosurgery oblique osteotomy of supraorbital margin of frontal bone for the treatment of unilateral coronal synostosis and to study the outcome and complications of this procedure. Oblique osteotomy allows for entry into the cranial cavity, and along with parallel cut to the roof of the orbit, avoids the need to cut into the orbit which forms the frontal flap. Oblique osteotomy was performed along the supraorbital rim to do a frontal suture of the glabella (ages of patients were less than 1 year) or on the opposite side of the supraorbital rim (ages of patients were older than 1 year) after performing a suturectomy of the effected coronal suture. Two internal distraction devices were subsequently placed across the osteotomized, fused coronal suture. Finally, the cranium pieces were divided in the middle and placed in the middle of the frontal bone using biological glue. Five days after the operation, a 0.6-mm distraction was done twice daily. The distraction was removed 6 months after reaching 2 to 3 cm. Internal distraction osteogenesis with supraorbital oblique osteotomy was performed in 9 patients suffering from unilateral coronal synostosis. Eight patients had no postoperative infections around the shaft puncture wounds. One patient had infection in the rods around the distraction during the period of fixed, but was cured with antibiotic treatment. During a mean follow-up period of 12 months (5-26 months), all patients were satisfied with the cosmetic and functional results. No complications, including fixed screw displacement, penetration of the cranium and dura mater or retraction of distraction devices, occurred. The devices were exposed in 1 patient, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients. Use of this procedure avoids the need for frontal osteotomy to move the orbit forward. Adding 2 cranium strips can be used to

Radiographic appearance of the middle ear after ventral bulla osteotomy in five dogs with otitis media

International Nuclear Information System (INIS)

Holt, D.E.; Walker, L.

1997-01-01

Radiographs of the middle ear were made in five dogs 60 to 78 months after ventral bulla osteotomy was performed to treat otitis media. The clinical results of surgery were considered satisfactory in four dogs and unsatisfactory in one. In 4 dogs with satisfactory results, radiographs demonstrated complete reformation of the bulla in 3 operated middle ears (3 dogs), with partial bulla reformation in the three middle ears (3 dogs). Radiographs in one dog with unsatisfactory results showed complete bulla reformation with no increase in lumen opacity. The proliferative bony response obliterating the middle ear previously reported in normal dogs after ventral bulla osteotomy was not seen in any of these patients

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.

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

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

Short-Term Radiographic Outcome After Distal Chevron Osteotomy for Hallux Valgus Using Intramedullary Plates With an Amended Algorithm for the Surgical Management of Hallux Valgus.

Science.gov (United States)

Matsumoto, Takumi; Gross, Christopher E; Parekh, Selene G

2018-03-01

Distal Chevron osteotomy is a well-established surgical procedure for mild to moderate hallux valgus deformity. Many methods have been described for fixation of osteotomy site; secure fixation, enabling large displacement of the metatarsal head, is one of the essentials of this procedure. The purpose of the present study was to evaluate the short-term radiographic outcome of a distal Chevron osteotomy using an intramedullary plate for the correction of hallux valgus deformity. The present study evaluated 37 patients (40 feet) who underwent distal Chevron osteotomy using an intramedullary plate by periodic radiographs obtained preoperatively and at 4 weeks, 8 weeks, 3 months, and 6 months postoperatively. Correction of the hallux valgus angle averaged 17.8°, intermetatarsal angle 7.4°, distal metatarsal articular angle 2.7°, and sesamoid position 1.4 stages at 3 months postoperatively. The average lateral shift of the capital fragment was 6.5 mm. All patients achieved bone union, and there were no cases of dislocation, displacement, or avascular necrosis of the metatarsal head fragment. In conclusion, a distal Chevron osteotomy using an intramedullary plate was a favorable method for the correction of mild to moderate hallux valgus deformity. Level IV: Case series.

[Lateral column lengthening osteotomy of calcaneus].

Science.gov (United States)

Hintermann, B

2015-08-01

Lengthening of the lateral column for adduction of forefoot and restoration of the medial arch. Stabilization of the ankle joint complex. Supple flatfoot deformity (posterior tibial tendon dysfunction stage II). Instability of the medial ankle joint complex (superficial deltoid and spring ligament). Posttraumatic valgus and pronation deformity of the foot. Rigid flatfoot deformity (posterior tibial tendon dysfunction stage III and IV). Talocalcaneal and naviculocalcaneal coalition. Osteoarthritis of calcaneocuboid joint. Exposition of calcaneus at sinus tarsi. Osteotomy through sinus tarsi and widening until desired correction of the foot is achieved. Insertion of bone graft. Screw fixation. Immobilization in a cast for 6 weeks. Weight-bearing as tolerated from the beginning. In the majority of cases, part of hindfoot reconstruction. Reliable and stable correction. Safe procedure with few complications.

Early outcomes of one-stage combined osteotomy in Legg-Calve´-Perthes disease

Directory of Open Access Journals (Sweden)

Basant Kumar Bhuyan

2016-01-01

Conclusions: The surgical treatment of LCPD with the best expected outcome is still a challenge. Advanced containment methods by one-stage combined osteotomy can be considered as an alternative treatment where femoral head subluxation or deformity which makes containment difficult or impossible by more conventional methods.

Mitchell′s osteotomy in the management of hallux valgus: An Indian perspective

Directory of Open Access Journals (Sweden)

Baba Asif

2009-01-01

Full Text Available Background: Hallux valgus is a common condition that affects the forefoot. A large number of procedures are described for managing this condition. Mitchell′s osteotomy and its modifications are being widely used for treating hallux valgus. However, most of the studies describe the results from the developed world. We present results of the classic Mitchell′s osteotomy in hallux valgus in Indian subcontinent. Materials and Methods: Forty eight adult patients (including 12 bilateral ones in the age range of 18-60 years with hallux valgus were managed with the classic Mitchell′s osteotomy. Pain over the bunion was the reason for surgery in 53 of 60 feet and cosmesis in the remaining 7 feet. Patients with hallux valgus angle more than 20° degrees and not responding to a trial of conservative treatment were included. Patients having metatarsophalangeal (MTP joint osteoarthritis (Grade II and higher, hallux rigidus, rheumatoid arthritis, and with subluxation of MTP joint were excluded from the study. Further, patients with first metatarsal more than 3 mm shorter than second metatarsal were also excluded. Results: The average follow-up period is 3 yrs (range 18months - 6yrs. About 55 feet (83% were painless after surgery. Forty-two (70% patients were happy with the cosmetic results of the surgery. Metatarsalgia was the reason for dissatisfaction with the procedure in five patients. The average correction of hallux valgus and the intermetatarsal angles achieved was 19.7° and 6.9°, respectively. Using the Broughton and Winson scoring system, 37 (61.7% feet had excellent results, 18 (30% had good, and five (8.3% feet had a poor results. Conclusion: The classic Mitchell′s procedure is a simple procedure and gives good cosmetic and radiological results.

Evaluation of Bone Healing After Osteotomies Prepared With Er:YAG Laser in Contact and Noncontact Modes and Piezosurgery--An Animal Study.

Science.gov (United States)

Gabrić, Dragana; Blašković, Marko; Gjorgijevska, Elizabeta; Mladenov, Mitko; Tašič, Blaž; Jurič, Ivona Bago; Ban, Ticijana

2016-01-01

To analyze the healing of bone tissue treated with Er:YAG laser contact and noncontact modes of and piezosurgery in a rat model using triangular laser profilometry. Twenty-four 10-week-old adult male Wistar rats were used in the study. Three osteotomies on the medial part of tibia were performed in each animal, 1 in the right tibia and 2 in the left tibia. The osteotomies were performed with a piezoelectric device set at maximal power and the Er:YAG laser in contact mode (power, 7.5 W; pulse energy, 375 mJ; repetition rate, 20 Hz; MSP mode) and noncontact mode (power, 7.5 W; pulse energy, 750 mJ; repetition rate, 10 Hz; QSP mode) with a novel type of circular, digitally controlled handpiece (x-Runner). After surgery, 6 animals were immediately euthanized (group 1), and the others were euthanized after 1 week (group 2, n = 6), 2 weeks (group 3, n = 6), and 3 weeks (group 4, n = 6). Bone healing after osteotomy was analyzed using a 3-dimensional laser scanning technique (ie, laser triangulation profilometry). The volume reduction rates are similar for all 3 techniques (0.2 to 0.25 mm(3) per week). Greater volume reduction of 0.25 mm3 per week was observed for the Er:YAG laser in noncontact mode (x-Runner). After 3 weeks, almost complete healing of the prepared osteotomy was observed. Within the limitations of this study, the osteotomies performed by the Er:YAG laser in digitally controlled noncontact mode healed the fastest. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Assessment of Neutron Contamination Originating from the Presence of Wedge and Block in Photon Beam Radiotherapy.

Science.gov (United States)

Bahreyni Toossi, M T; Khajetash, B; Ghorbani, M

2018-03-01

One of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. Objective: In the present study the impact of wedge and block on neutron contamination production is investigated. The evaluations are conducted for a 15 MV Siemens Primus linear accelerator. Simulations were performed using MCNPX Monte Carlo code. 30˚, 45˚ and 60˚ wedges and a cerrobend block with dimensions of 1.5 × 1.5 × 7 cm 3 were simulated. The investigation were performed in the 10 × 10 cm 2 field size at source to surface distance of 100 cm for depth of 0.5, 2, 3 and 4 cm in a water phantom. Neutron dose was calculated using F4 tally with flux to dose conversion factors and F6 tally. Results showed that the presence of wedge increases the neutron contamination when the wedge factor was considered. In addition, 45˚ wedge produced the most amount of neutron contamination. If the block is in the center of the field, the cerrobend block caused less neutron contamination than the open field due to absorption of neutrons and photon attenuation. The results showed that neutron contamination is less in steeper depths. The results for two tallies showed practically equivalent results. Wedge causes neutron contamination hence should be considered in therapeutic protocols in which wedge is used. In terms of clinical aspects, the results of this study show that superficial tissues such as skin will tolerate more neutron contamination than the deep tissues.

Bad splits in bilateral sagittal split osteotomy: systematic review of fracture patterns.

Science.gov (United States)

Steenen, S A; Becking, A G

2016-07-01

An unfavourable and unanticipated pattern of the mandibular sagittal split osteotomy is generally referred to as a 'bad split'. Few restorative techniques to manage the situation have been described. In this article, a classification of reported bad split pattern types is proposed and appropriate salvage procedures to manage the different types of undesired fracture are presented. A systematic review was undertaken, yielding a total of 33 studies published between 1971 and 2015. These reported a total of 458 cases of bad splits among 19,527 sagittal ramus osteotomies in 10,271 patients. The total reported incidence of bad split was 2.3% of sagittal splits. The most frequently encountered were buccal plate fractures of the proximal segment (types 1A-F) and lingual fractures of the distal segment (types 2A and 2B). Coronoid fractures (type 3) and condylar neck fractures (type 4) have seldom been reported. The various types of bad split may require different salvage approaches. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Spacing of Imbricated Thrust Faults and the Strength of Thrust-Belts and Accretionary Wedges

Science.gov (United States)

Ito, G.; Regensburger, P. V.; Moore, G. F.

2017-12-01

The pattern of imbricated thrust blocks is a prominent characteristic of the large-scale structure of thrust-belts and accretionary wedges around the world. Mechanical models of these systems have a rich history from laboratory analogs, and more recently from computational simulations, most of which, qualitatively reproduce the regular patterns of imbricated thrusts seen in nature. Despite the prevalence of these patterns in nature and in models, our knowledge of what controls the spacing of the thrusts remains immature at best. We tackle this problem using a finite difference, particle-in-cell method that simulates visco-elastic-plastic deformation with a Mohr-Coulomb brittle failure criterion. The model simulates a horizontal base that moves toward a rigid vertical backstop, carrying with it an overlying layer of crust. The crustal layer has a greater frictional strength than the base, is cohesive, and is initially uniform in thickness. As the layer contracts, a series of thrust blocks immerge sequentially and form a wedge having a mean taper consistent with that predicted by a noncohesive, critical Coulomb wedge. The widths of the thrust blocks (or spacing between adjacent thrusts) are greatest at the front of the wedge, tend to decrease with continued contraction, and then tend toward a pseudo-steady, minimum width. Numerous experiments show that the characteristic spacing of thrusts increases with the brittle strength of the wedge material (cohesion + friction) and decreases with increasing basal friction for low (laws that will illuminate the basic physical processes controlling systems, as well as allow researchers to use observations of thrust spacing as an independent constraint on the brittle strength of wedges as well as their bases.

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

A quantum hybrid with a thin antenna at the vertex of a wedge

Energy Technology Data Exchange (ETDEWEB)

Carlone, Raffaele, E-mail: raffaele.carlone@unina.it [Università “Federico II” di Napoli, Dipartimento di Matematica e Applicazioni “R. Caccioppoli”, MSA, via Cinthia, I-80126, Napoli (Italy); Posilicano, Andrea, E-mail: andrea.posilicano@uninsubria.it [DiSAT, Università dell' Insubria, via Valleggio 11, I-22100, Como (Italy)

2017-03-26

We study the spectrum, resonances and scattering matrix of a quantum Hamiltonian on a “hybrid surface” consisting of a half-line attached by its endpoint to the vertex of a concave planar wedge. At the boundary of the wedge, outside the vertex, homogeneous Dirichlet conditions are imposed. The system is tunable by varying the measure of the angle at the vertex. - Highlights: • Spectral characterization of a quantum Hamiltonian on “hybrid surface” consisting of a halfline attached to the vertex of a concave planar wedge. • The system is tunable by varying the measure of the angle at the vertex. • Relation between the conduction properties inside the hybrid and formation of resonances. • Easy generalization of the results to more complicated structures.

Interaction of Structure and Physical Properties in Accretionary Wedges: Examples from the Cascadia and Nankai Trough Subduction Zones

Science.gov (United States)

Webb, Susanna I.

Subduction zones are capable of producing large, megathrust earthquakes that are sometimes tsunamigenic. Structure and physical properties in the accretionary wedge play a role in how far rupture can propagate and how the wedge deforms coseismically. In this dissertation, I use seismic reflection data and velocity models from the Cascadia subduction zone and logging data from the Nankai Trough, Japan, to interpret structure, link structure to the broader wedge deformation history, and investigate the material properties at depth. I present a full structural interpretation of newly acquired seismic reflection data in the central Cascadia margin, which is characterized by dominantly landward vergent faulting in the outer wedge, a very low wedge taper angle, and a broad, lightly deformed lower slope terrace. Two decollements are active: an upper decollement within the sedimentary section, and a basal decollement at the sediment-basement interface. These interpretations help delineate the spatial extent of decollements and suggest that supra-wedge sedimentation may influence the development of the wedge, including the formation of the lower slope terrace and out of sequence fault activity. I use velocity models from central Cascadia to estimate excess pore fluid pressure and overpressure ratio at depth, which do not exceed 5 MPa and 0.15, respectively. No excess pore pressure is documented in the underthrust sediment section, but modest overpressure is likely present in the incoming sediment section and the footwalls of thrust sheets. The analysis of pore pressure shows that (1) if the base of the wedge is weak, it is due to mechanical properties of the sediments or a relatively thin underthrust layer and (2) the Cascadia wedge is relatively well-drained, and thus potentially strong, which can lead to a low wedge taper angle. In the Nankai Trough, Japan, I reprocessed sonic log data to obtain P-wave and S-wave velocity values and estimate elastic moduli. The logs

Complex Osteotomies of Tibial Plateau Malunions Using Computer-Assisted Planning and Patient-Specific Surgical Guides.

Science.gov (United States)

Fürnstahl, Philipp; Vlachopoulos, Lazaros; Schweizer, Andreas; Fucentese, Sandro F; Koch, Peter P

2015-08-01

The accurate reduction of tibial plateau malunions can be challenging without guidance. In this work, we report on a novel technique that combines 3-dimensional computer-assisted planning with patient-specific surgical guides for improving reliability and accuracy of complex intraarticular corrective osteotomies. Preoperative planning based on 3-dimensional bone models was performed to simulate fragment mobilization and reduction in 3 cases. Surgical implementation of the preoperative plan using patient-specific cutting and reduction guides was evaluated; benefits and limitations of the approach were identified and discussed. The preliminary results are encouraging and show that complex, intraarticular corrective osteotomies can be accurately performed with this technique. For selective patients with complex malunions around the tibia plateau, this method might be an attractive option, with the potential to facilitate achieving the most accurate correction possible.

Measuring linac photon beam energy through EPID image analysis of physically wedged fields

Energy Technology Data Exchange (ETDEWEB)

Dawoud, S. M., E-mail: samir.dawoud@leedsth.nhs.uk; Weston, S. J.; Bond, I.; Ward, G. C.; Rixham, P. A.; Mason, J.; Huckle, A. [Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom); Sykes, J. R. [Institute of Medical Physics, School of Physics, The University of Sydney, New South Wales 2006, Australia and Department of Medical Physics and Engineering, St. James Institute of Oncology, St. James University Hospital, Leeds LS9 7TF (United Kingdom)

2014-02-15

�0.3%). The repeat measurements over a three month period showed the method to be reasonably consistent (i.e., well within the limits defined by local QA tolerances). The measurements were repeated on a matched machine and the same linear relationship between α and PDD{sub 10} was observed. The results for both machines were found to be indistinguishable across the energy range of interest (i.e., across and close to the thresholds defined by local QA tolerances), hence a single relation could be established across a matched fleet. Finally, the experiment was repeated on both linacs at 10 MV, where the linear relationship between α and PDD{sub 10} was again observed. Conclusions: The authors conclude that EPID image analysis of physically wedged beam profiles can be used to measure linac photon beam energy. The uncertainty in such a measurement is dominated by that associated with measuring PDD{sub 10} in the water-tank; hence, the accuracies of these two methods are directly comparable. This method provides a useful technique for quickly performing energy constancy measurements while saving significant clinical downtime for QA.

Outcomes in chevron osteotomy for Hallux Valgus in a large cohort.

Science.gov (United States)

van Groningen, Bart; van der Steen, M C Marieke; Reijman, Max; Bos, Janneke; Hendriks, Johannes G E

2016-12-01

Clinical and radiological related outcomes have been reported for Chevron osteotomy as correction for mild to moderate hallux valgus, but only for relatively small patient series. Moreover, evaluation of the patient's point of view has mostly been conducted by means of more physician-based outcome measures. The goal of this study was to evaluate the effect of the Chevron osteotomy for hallux valgus on patients' daily lives using the Foot and Ankle Outcome Score (FAOS) as a validated and a hallux valgus specific patient reported outcome measure (PROM). Secondary outcome measures were radiological correction, complication rate, and re-operations. All 438 Chevron procedures (336 patients), at two surgical hospital sites in the period between January 2010 and October 2014, were retrospectively evaluated with a follow-up of at least 6 months. Patients were invited to fill in a cross-sectional online FAOS. For the FAOS, a total response of 60% was achieved. The FAOS ranged between 71 and 88 with a follow-up of on average 36 months. Patients with an undercorrection of their hallux valgus (11.6% of the procedures) scored significantly lower on three subscales of the FAOS (range between 61 and 77 versus 72-84). Patients who had a reoperation (12.6% of the procedures) also scored significantly lower on four subscales: 58-100 versus 73-89. Postoperative radiological measurements improved significantly with a mean difference of 6.1 (5.9; 6.4) degrees for the intermetatarsal angle and 13.7 (13.0; 14.5) degrees for the hallux valgus angle. In this large study cohort, Chevron osteotomy for hallux valgus offers good PROM scores on FAOS. These scores were significantly lower in patients with radiological undercorrection or with a reoperation. Results of the FAOS appear to modulate with physician based outcomes and therapeutic incidents. Improvement of outcome may therefore well be possible by increased attention on these surgical details. Copyright © 2016 Elsevier Ltd. All rights

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.

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.

Study and evaluation of the Siemens virtual wedge factor: dosimetric monitor system and variable field effects

Energy Technology Data Exchange (ETDEWEB)

Sendon Rio, J R Sendon; Martinez, C Otero; GarcIa, M Sanchez; Busto, R Lobato; Vega, V Luna; Sueiro, J Mosquera; Camean, M Pombar [Servizo de Radiofisica e Proteccion Radioloxica, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Santiago de Compostela (Spain)], E-mail: jose.ramon.sendon.del.rio@sergas.es

2008-03-07

In the year 1997 Siemens introduced the virtual wedge in its accelerators. The idea was that a dose profile similar to that of a physical wedge can be obtained by moving one of the accelerator jaws at a constant speed while the dose rate is changing. This work explores the observed behaviour of virtual wedge factors. A model is suggested which takes into account that at any point in time, when the jaw moves, the dose at a point of interest in the phantom is not only due to the direct beam. It also depends on the scattered radiation in the phantom, the head scatter and the behaviour of the monitoring system of the accelerator. Measurements are performed in a Siemens Primus accelerator and compared to the model predictions. It is shown that the model agrees reasonably well with measurements spanning a wide range of conditions. A strong dependence of virtual wedge factors on the dosimetric board has been confirmed and an explanation has been given on how the balance between different contributions is responsible for virtual wedge factors values.

Three-dimensional computed tomographic evaluation of bilateral sagittal split osteotomy lingual fracture line and le fort I pterygomaxillary separation in orthognathic surgery using cadaver heads: ultrasonic osteotome versus conventional saw.

Science.gov (United States)

Dammous, Sophie; Dupont, Quentin; Gilles, Roland

2015-06-01

The purpose of this study was to observe the quality of the fracture line on the lingual side of the mandible after sagittal split osteotomy and the quality of pterygomaxillary separation after Le Fort I osteotomy using the BoneScalpel ultrasonic osteotome. Bimaxillary procedures, according to the standard protocol, were performed using 10 fresh cadaver heads. The ultrasonic osteotome was used in the study group, and a reciprocating saw was used in the control group. Three-dimensional reconstructions of postoperative computed tomographic scans were obtained. The lingual ramus fracture pattern and the pterygomaxillary separation pattern were observed, classified, and compared. Postoperative dissections of the skulls were performed to assess the integrity of the infra-alveolar nerve and the descending palatine artery. No significant differences were found in the cutting time of bone between the BoneScalpel and the sagittal saw. Of the sagittal split osteotomies in the study group, 90% showed a good pattern (vertical pattern of fracture line extending to the inferior border of the mandible running behind the mandibular canal) compared with 50% of the sagittal split osteotomies in the control group. Ideal separation of the pterygoid plates without fractures was observed in 80% of the Le Fort I osteotomies in the study group compared with 50% of the osteotomies in the control group. High-level fractures occurred in 30% of cases in the control group compared with none in the study group. The integrities of the infra-alveolar nerve and the descending palatine artery were preserved in all cases. Use of the ultrasonic BoneScalpel did not require more time than the conventional method. An improved pattern of lingual fracture lines in mandibular sagittal split osteotomy procedures and the pattern of pterygomaxillary separation in Le Fort I osteotomy procedures were observed. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc

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

Fixed Points of Maps of a Nonaspherical Wedge

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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 .

A multisatellite case study of the expansion of a substorm current wedge in the near-Earth magnetotail

International Nuclear Information System (INIS)

Lopez, R.E.; Lui, A.T.Y.

1990-01-01

This study presents observations made by four spacecraft (AMPTE CCE, AMPTE IRM, GOES 5, and GOES 6) and two ground stations (San Juan and Tucson) during a substorm that occurred at ∼0830 UT on April 19, 1985. The spacecraft were arrayed in a configuration that allows for the examination of the spatial evolution of the substorm current wedge, CCE was located between the GOES spacecraft in longitude, but at a radial distance of 8.0 R E . IRM was located west of the other three spacecraft in the same sector as Tucson, but at a radial distance of 11.6 R E . The relative times at which the signature of the substorm current wedge was first observed at the GOES spacecraft and the ground stations are consistent with a simple longitudinally expanding current wedge. However, the times at which IRM and CCE observed the current wedge are not consistent with a current wedge that expanded only longitudinally, IRM first observed the signature of the current wedge at about the same time the signature was observed by GOES 6 and Tucson, and CCE observed the current wedge only after both GOES satellites and the ground stations had done so. Moreover, both GOES spacecraft observed signatures consistent with entry into the central plasma sheet before CCE and IRM did, even though we estimate that CCE was slightly closer to the neutral sheet than the geosynchronous spacecraft. The sequence of events suggests that during this substorm the disruption of the cross-tail current sheet, the formation of the substorm current wedge, and the expansion of the plasma sheet began in the near-Earth region, and subsequently spread tailward as well as longitudinally

Celecoxib does not significantly delay bone healing in a rat femoral osteotomy model: a bone histomorphometry study

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Iwamoto J

2011-12-01

Full Text Available Jun Iwamoto1, Azusa Seki2, Yoshihiro Sato3, Hideo Matsumoto11Institute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, Japan; 2Hamri Co, Ltd, Tokyo, Japan; 3Department of Neurology, Mitate Hospital, Fukuoka, JapanBackground and objective: The objective of the present study was to determine whether celecoxib, a cyclo-oxygenase-2 inhibitor, would delay bone healing in a rat femoral osteotomy model by examining bone histomorphometry parameters.Methods: Twenty-one 6-week-old female Sprague-Dawley rats underwent a unilateral osteotomy of the femoral diaphysis followed by intramedullary wire fixation; the rats were then divided into three groups: the vehicle administration group (control, n = 8, the vitamin K2 administration (menatetrenone 30 mg/kg orally, five times a week group (positive control, n = 5, and the celecoxib administration (4 mg/kg orally, five times a week group (n = 8. After 6 weeks of treatment, the wires were removed, and a bone histomorphometric analysis was performed on the bone tissue inside the callus. The lamellar area relative to the bone area was significantly higher and the total area and woven area relative to the bone area were significantly lower in the vitamin K2 group than in the vehicle group. However, none of the structural parameters, such as the callus and bone area relative to the total area, lamellar and woven areas relative to the bone area, or the formative and resorptive parameters such as osteoclast surface, number of osteoclasts, osteoblast surface, osteoid surface, eroded surface, and bone formation rate per bone surface differed significantly between the vehicle and celecoxib groups.Conclusion: The present study implies that celecoxib may not significantly delay bone healing in a rat femoral osteotomy model based on the results of a bone histomorphometric analysis.Keywords: femoral osteotomy, bone healing, callus, rat, celecoxib

Comparing fixation used for calcaneal displacement osteotomies: a look at removal rates and cost.

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Lucas, Douglas E; Simpson, G Alex; Philbin, Terrence M

2015-02-01

The calcaneal displacement osteotomy is a procedure frequently used by foot and ankle surgeons for hindfoot angular deformity. Traditional techniques use compression screw fixation that can result in prominent hardware. While the results of the procedure are generally good, a common concern is the development of plantar heel pain related to prominent hardware. The primary purpose of this study is to retrospectively compare clinical outcomes of 2 fixation methods for the osteotomy. Secondarily a cost analysis will compare implant costs to hardware removal costs. Records were reviewed for patients who had undergone a calcaneal displacement osteotomy fixated with either lag screw or a locked lateral compression plate (LLCP). Neuropathy, previous ipsilateral calcaneus surgery, heel pad trauma, or incomplete radiographic follow-up were exclusionary. Thirty-two patients (19.4%) required hardware removal from the screw fixation group compared to 1 (1.6%) of the LLCP group, which is significant (P cost was remarkably different with screw fixation costing on average $247.12, compared to the LLCP costing $1175.59. Although the LLCP cost was significantly higher, cost savings were identified when the cost of removal and removal rates were included. This study demonstrates that this device provides adequate stabilization for healing in equivalent time to screw fixation. The LLCP required decreased rates of hardware removal with fewer postoperative visits over a shorter period of time. Significant savings were demonstrated in the LLCP group despite the higher implant cost. Therapeutic, Level III, Retrospective Comparative Study. © 2014 The Author(s).

[Osteotomies for treating developmental disorders of the neurocranium and visceral cranium].

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Mühling, J

1991-02-01

Craniofacial deformities are primarily caused by premature synostosis of cranial sutures. Depending on the involved sutures, typical deformities of the neuro- and visceral cranium are produced. They result in severe functional and aesthetic disturbances. Several osteotomies, which do not only make an aesthetic improvement possible but a correction of severe malfunction, are available for therapy. Preoperative planning and postoperative treatment require the combination of orthodontics and maxillofacial surgery.

A comparison of proximal and distal Chevron osteotomy, both with lateral soft-tissue release, for moderate to severe hallux valgus in patients undergoing simultaneous bilateral correction: a prospective randomised controlled trial.

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Lee, K B; Cho, N Y; Park, H W; Seon, J K; Lee, S H

2015-02-01

Moderate to severe hallux valgus is conventionally treated by proximal metatarsal osteotomy. Several recent studies have shown that the indications for distal metatarsal osteotomy with a distal soft-tissue procedure could be extended to include moderate to severe hallux valgus. The purpose of this prospective randomised controlled trial was to compare the outcome of proximal and distal Chevron osteotomy in patients undergoing simultaneous bilateral correction of moderate to severe hallux valgus. The original study cohort consisted of 50 female patients (100 feet). Of these, four (8 feet) were excluded for lack of adequate follow-up, leaving 46 female patients (92 feet) in the study. The mean age of the patients was 53.8 years (30.1 to 62.1) and the mean duration of follow-up 40.2 months (24.1 to 80.5). After randomisation, patients underwent a proximal Chevron osteotomy on one foot and a distal Chevron osteotomy on the other. At follow-up, the American Orthopedic Foot and Ankle Society (AOFAS) hallux metatarsophalangeal interphalangeal (MTP-IP) score, patient satisfaction, post-operative complications, hallux valgus angle, first-second intermetatarsal angle, and tibial sesamoid position were similar in each group. Both procedures gave similar good clinical and radiological outcomes. This study suggests that distal Chevron osteotomy with a distal soft-tissue procedure is as effective and reliable a means of correcting moderate to severe hallux valgus as proximal Chevron osteotomy with a distal soft-tissue procedure. ©2015 The British Editorial Society of Bone & Joint Surgery.

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

Thermal regime of an ice-wedge polygon landscape near Barrow, Alaska

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Daanen, R. P.; Liljedahl, A. K.

2017-12-01

Tundra landscapes are changing all over the circumpolar Arctic due to permafrost degradation. Soil cracking and infilling of meltwater repeated over thousands of years form ice wedges, which produce the characteristic surface pattern of ice-wedge polygon tundra. Rapid top-down thawing of massive ice leads to differential ground subsidence and sets in motion a series of short- and long-term hydrological and ecological changes. Subsequent responses in the soil thermal regime drive further permafrost degradation and/or stabilization. Here we explore the soil thermal regime of an ice-wedge polygon terrain near Utqiagvik (formerly Barrow) with the Water balance Simulation Model (WaSiM). WaSiM is a hydro-thermal model developed to simulate the water balance at the watershed scale and was recently refined to represent the hydrological processes unique to cold climates. WaSiM includes modules that represent surface runoff, evapotranspiration, groundwater, and soil moisture, while active layer freezing and thawing is based on a direct coupling of hydrological and thermal processes. A new snow module expands the vadose zone calculations into the snow pack, allowing the model to simulate the snow as a porous medium similar to soil. Together with a snow redistribution algorithm based on local topography, this latest addition to WaSiM makes simulation of the ground thermal regime much more accurate during winter months. Effective representation of ground temperatures during winter is crucial in the simulation of the permafrost thermal regime and allows for refined predictions of future ice-wedge degradation or stabilization.

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

Evaluation of instability after transtrochanteric anterior rotational osteotomy for nontraumatic osteonecrosis of the femoral head

International Nuclear Information System (INIS)

Hiranuma, Yasunari; Atsumi, Takashi; Kajiwara, Toshihisa; Tamaoki, Satoshi; Asakura, Yasuhiro

2009-01-01

Transtrochanteric anterior rotational osteotomy results in improvement of joint congruity and prevention of progressive collapse and osteoarthritic changes in patients with femoral head osteonecrosis. However, this procedure remains controversial for patients with extensive collapse due to potential osteoarthritis caused by postoperative instability. The purpose of this study was to evaluate hip instability after osteotomy and determine the relation between instability and radiological and clinical outcomes. In all, 27 hips of 24 patients that were followed up for a mean period of 3.8 years were included. Instability was defined as more than 1 mm translation of the femoral head in transverse computed tomography scans obtained at 0 deg and 45 deg flexion of the hip joint. Hips were divided into instability and stability groups. Eleven hips (40%) developed instability after surgery. Osteophytes on the femoral head in 10 hips of the instability group and 2 hips of the stability group had increased in size at follow-up. There was a significant relation between postoperative instability and osteophyte formation. Joint space narrowing was not seen in any of the cases. There was no significant difference between the groups in either the postoperative intact ratio of the femoral head or the Japanese Orthopaedic Association hip score. Neither instability nor osteophyte formation on the femoral head after transtrochanteric anterior rotational osteotomy correlated with progressive osteoarthritic changes or clinical outcome in the presence of an adequate femoral head intact ratio facing the weight-bearing area. (author)

Chevron osteotomy for the treatment of hallux valgus.

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Horne, G; Tanzer, T; Ford, M

1984-03-01

Seventy-six chevron osteotomies with follow-up periods ranging from six months to eight years were reviewed. The majority of patients had pain over the bunion prior to operation, and 27 also presented with second metatarsalgia. After surgery there was a marked decrease of pain in the first metatarsophalangeal joint, and in 18 feet the second metatarsalgia was either eliminated or markedly decreased. Most patients were pleased with the appearance of the feet after surgery, but almost one-third of the women complained of difficulty in wearing high heels. The surgical technique is straightforward, but careful attention to detail is necessary to obtain a consistent and satisfactory result.

Direct FVM Simulation for Sound Propagation in an Ideal Wedge

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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.

A Systematic Review on Effect of Single-Dose Preoperative Antibiotics at Surgical Osteotomy Extraction of Lower Third Molars

DEFF Research Database (Denmark)

Marcussen, Karoline Brørup; Laulund, Anne Sofie; Jørgensen, Henrik L

2016-01-01

PURPOSE: We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of a single dose of preoperative antibiotic administered perorally, intravenously, intramuscularly, or topically for preventing infection and alveolar osteitis in lower third molar...... that penicillin V was effective in reducing the incidence of alveolar osteitis (OR = 0.1; 95% CI, 0.03 to 0.30; P ≤ .0001). CONCLUSIONS: A single oral dose of 2 g of amoxicillin before lower third molar osteotomy surgical extraction significantly decreased the incidence of SSI. A single dose of 0.8 g...... of penicillin V before lower third molar osteotomy surgical extraction significantly decreased the incidence of alveolar osteitis....

Measurement of dynamic wedge angles and beam profiles by means of MRI ferrous sulphate gel dosimetry

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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.

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...

Acute Reciprocal Changes Distant from the Site of Spinal Osteotomies Affect Global Postoperative Alignment

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Eric Klineberg

2011-01-01

Full Text Available Introduction. Three-column vertebral resections are frequently applied to correct sagittal malalignment; their effects on distant unfused levels need to be understood. Methods. 134 consecutive adult PSO patients were included (29 thoracic, 105 lumbar. Radiographic analysis included pre- and postoperative regional curvatures and pelvic parameters, with paired independent t-tests to evaluate changes. Results. A thoracic osteotomy with limited fusion leads to a correction of the kyphosis and to a spontaneous decrease of the unfused lumbar lordosis (−8°. When the fusion was extended, the lumbar lordosis increased (+8°. A lumbar osteotomy with limited fusion leads to a correction of the lumbar lordosis and to a spontaneous increase of the unfused thoracic kyphosis (+13°. When the fusion was extended, the thoracic kyphosis increased by 6°. Conclusion. Data from this study suggest that lumbar and thoracic resection leads to reciprocal changes in unfused segments and requires consideration beyond focal corrections.

Minimally Invasive and Open Distal Chevron Osteotomy for Mild to Moderate Hallux Valgus.

Science.gov (United States)

Brogan, Kit; Lindisfarne, Edward; Akehurst, Harold; Farook, Usama; Shrier, Will; Palmer, Simon

2016-11-01

Minimally invasive surgical (MIS) techniques are increasingly being used in foot and ankle surgery but it is important that they are adopted only once they have been shown to be equivalent or superior to open techniques. We believe that the main advantages of MIS are found in the early postoperative period, but in order to adopt it as a technique longer-term studies are required. The aim of this study was to compare the 2-year outcomes of a third-generation MIS distal chevron osteotomy with a comparable traditional open distal chevron osteotomy for mild-moderate hallux valgus. Our null hypothesis was that the 2 techniques would yield equivalent clinical and radiographic results at 2 years. This was a retrospective cohort study. Eighty-one consecutive feet (49 MIS and 32 open distal chevron osteotomies) were followed up for a minimum 24 months (range 24-58). All patients were clinically assessed using the Manchester-Oxford Foot Questionnaire. Radiographic measures included hallux valgus angle, the intermetatarsal angle, hallux interphalangeal angle, metatarsal phalangeal joint angle, distal metatarsal articular angle, tibial sesamoid position, shape of the first metatarsal head, and plantar offset. Statistical analysis was done using Student t test or Wilcoxon rank-sum test for continuous data and Pearson chi-square test for categorical data. Clinical and radiologic postoperative scores in all domains were substantially improved in both groups (P .05). There were no significant differences in complications between the 2 groups ( > .5). The midterm results of this third-generation technique show that it was a safe procedure with good clinical outcomes and comparable to traditional open techniques for symptomatic mild-moderate hallux valgus. Level III, retrospective comparative study. © The Author(s) 2016.

Description and evaluation of operative deformity correction in calcium-deficiency rickets in Kaduna, northern Nigeria.

Science.gov (United States)

Wesselsky, Viktor; Kitz, Christa; Jakob, Franz; Eulert, Jochen; Raab, Peter

2016-04-01

Rickets is a recurrent disease worldwide, especially in countries with limited resources (Nield et al Am Fam Physician 74(4):619-626, 2006; Thacher et al Ann Trop Paediatr 26(1):1-16, 2006). Medical therapy including orally administered calcium substitution is shown to improve a patients clinical symptoms and positively impact bone deformities, especially in the lower extremity. Even though orthopaedic intervention is necessary in a significant percentage of patients, few reports exist about operative deformity correction in patients wtih rickets. We describe our concept of operative treatment by single-stage, three-dimensional closing-wedge osteotomies on 45 deformed legs in 27 patients from the rural area of Kaduna, North Nigeria, with calcium-deficiency rickets and evaluate the early results in a 1.5-year follow-up. We found a significant improvement in parameters of quality of life, functionality, clinical and radiological angulation and angles following the definition of Paley et al., with a complication rate of 4 % under 88 osteotomies (Paley et al Orthop Clin North Am 25(3):425-65, 1994). The described operative therapy shows to be sufficient and with satisfactory results in correcting rickets-related leg deformities under rural circumstances with low availability of medical resources.

CORRECTION OF SEVERE STIFF SCOLIOSIS THROUGH EXTRAPLEURAL INTERBODY RELEASE AND OSTEOTOMY (LIEPO

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Cleiton Dias Naves

Full Text Available ABSTRACT Objective: To report a new technique for extrapleural interbody release with transcorporal osteotomy of the inferior vertebral plateau (LIEPO and to evaluate the correction potential of this technique and its complications. Method: We included patients with scoliosis with Cobb angle greater than 90° and flexibility less than 25% submitted to surgical treatment between 2012 and 2016 by the technique LIEPO at the National Institute of Traumatology and Orthopedics (INTO. Sagittal and coronal alignment, and the translation of the apical vertebra were measured and the degree of correction of the deformity was calculated through the pre and postoperative radiographs, and the complications were described. Results: Patients had an average bleed of 1,525 ml, 8.8 hours of surgical time, 123° of scoliosis in the preoperative period, and a mean correction of 66%. There was no case of permanent neurological damage and no surgical revision. Conclusion: The LIEPO technique proved to be effective and safe in the treatment of severe stiff scoliosis, reaching a correction potential close to the PEISR (Posterior extrapleural intervertebral space release technique and superior to that of the pVCR (posterior Vertebral Column Resection with no presence of infection and permanent neurological deficit. New studies are needed to validate this promising technique.

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

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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

Inverted 'V' osteotomy excision arthroplasty for bony ankylosed elbows

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Rex Chadrabose

2011-12-01

Full Text Available Abstract Background Bony ankylosis of elbow is challenging and difficult problem to treat. The options are excision arthroplasty and total elbow replacement. We report our midterm results on nine patients, who underwent inverted 'V' osteotomy excision arthroplasty in our hospital with good functional results. Materials Our case series includes 9 patients (seven males and two females with the mean age of 34 years (13-56 years. Five patients had trauma, two had pyogenic arthritis, one had tuberculous arthritis, and one had pyogenic arthritis following surgical fixation. Results The average duration of follow up is 65 months (45 months-80 months. The mean Mayo's elbow performance score (MEPS preoperatively was 48 (35-70. The MEPS at final follow up was 80 (60-95. With no movement at elbow and fixed in various degrees of either flexion or extension preoperatively, the mean preoperative position of elbow was 64°(30°to 100°. The mean post operative range of motion at final follow up was 27°of extension (20-500, 116°of flexion (1100-1300, and the arc of motion was 88°(800-1000. One patient had ulnar nerve neuropraxia and another patient developed median nerve neuropraxia, and both recovered completely in six weeks. No patient had symptomatic instability of the elbow. All patients were asymptomatic except one patient, who had pain mainly on heavy activities. Conclusion We conclude that inverted 'V' osteotomy excision arthroplasty is a viable option in the treatment of bony ankylosis of the elbow in young patients.

Three-dimensional semi-analytical solution to groundwater flow in confined and unconfined wedge-shaped aquifers

Science.gov (United States)

Sedghi, Mohammad Mahdi; Samani, Nozar; Sleep, Brent

2009-06-01

The Laplace domain solutions have been obtained for three-dimensional groundwater flow to a well in confined and unconfined wedge-shaped aquifers. The solutions take into account partial penetration effects, instantaneous drainage or delayed yield, vertical anisotropy and the water table boundary condition. As a basis, the Laplace domain solutions for drawdown created by a point source in uniform, anisotropic confined and unconfined wedge-shaped aquifers are first derived. Then, by the principle of superposition the point source solutions are extended to the cases of partially and fully penetrating wells. Unlike the previous solution for the confined aquifer that contains improper integrals arising from the Hankel transform [Yeh HD, Chang YC. New analytical solutions for groundwater flow in wedge-shaped aquifers with various topographic boundary conditions. Adv Water Resour 2006;26:471-80], numerical evaluation of our solution is relatively easy using well known numerical Laplace inversion methods. The effects of wedge angle, pumping well location and observation point location on drawdown and the effects of partial penetration, screen location and delay index on the wedge boundary hydraulic gradient in unconfined aquifers have also been investigated. The results are presented in the form of dimensionless drawdown-time and boundary gradient-time type curves. The curves are useful for parameter identification, calculation of stream depletion rates and the assessment of water budgets in river basins.

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

Association between open or closed reduction and avascular necrosis in developmental dysplasia of the hip

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Wang, Ya-Jie; Yang, Fan; Wu, Qi-Jun; Pan, Shi-Nong; Li, Lian-Yong

2016-01-01

Abstract Background: The risk of avascular necrosis of the femoral head (AVN) after treatment of developmental dysplasia of the hip is associated with the method of reduction. Some authors have suggested that open reduction is a risk factor for AVN; however, this is controversial. To our knowledge, a quantitative comparison of the incidence of AVN between closed and open reduction has not been conducted. Methods: Published studies were identified by searching PubMed, EMBASE, and the Cochrane Library up to May, 2015, focusing on the incidence of AVN after closed or open reduction for developmental dysplasia of the hip in children aged <3 years. Patients were age-matched who were treated by either closed or open reduction, but without pelvic or femoral osteotomy. Two authors independently assessed eligibility and abstracted data. Discrepancies were discussed and resolved by consensus. We pooled the odds ratios (ORs) and 95% confidence intervals (95%CIs) from individual studies using a random-effects model and evaluated heterogeneity and publication bias. Results: Nine retrospective studies were included in this analysis. The pooled OR for comparing open reduction with closed reduction for all grades of AVN was 2.26 (95%CI = 1.21–4.22), with moderate heterogeneity (I2 = 44.7%, P = 0.107). The pooled OR for grades II to IV AVN was 2.46 (95%CI = 0.93–6.51), with high heterogeneity (I2 = 69.6%, P = 0.003). A significant association was also found for the further surgery between open and closed reduction, with a pooled OR of 0.30 (95%CI = 0.15–0.60) and moderate heterogeneity (I2 = 46.4%, P = 0.133). No evidence of publication bias or significant heterogeneity between subgroups was detected by meta-regression analyses. Conclusion: Findings from this meta-analysis suggest that open reduction is a risk factor for the development of AVN compared with closed treatment. Future studies are warranted to investigate how open reduction

Computed Tomography Based Three-dimensional Measurements of Spine Shortening Distance After Posterior Three-column Osteotomies for the Treatment of Severe and Stiff Scoliosis.

Science.gov (United States)

Li, Xue-Shi; Huang, Zi-Fang; Deng, Yao-Long; Fan, Heng-Wei; Sui, Wen-Yuan; Wang, Chong-Wen; Yang, Jun-Lin

2017-07-15

Retrospective study. This study is to measure and analyze the changes of three-dimensional (3D) distances of spinal column and spinal canal at the three-column osteotomy sites and address their clinical and neurologic significance. Three-column osteotomies were developed to treat severe and stiff spine deformities with insufficient understanding on the safe limit of spine shortening and the relationship between the shortening distance of the spinal column and that of the spinal canal. Records of 52 continuous patients with severe and stiff scoliosis treated with three-column spine osteotomies at our institution from July 2013 to June 2015 were reviewed. The preoperative spinal cord function classification were type A in 31 cases, type B in 10 cases, and type C in 11 cases. The types of osteotomies carried out were extended pedicle subtraction osteotomy in nine patients and posterior vertebral column resection in 43 patients. Multimodality neuromonitoring strategies were adopted intraoperatively. 3D pre- and postoperative spine models were reconstructed from the computed tomography (CT) scans. The distances of convex and concave spinal column and the spinal canal shortening were measured and analyzed. The spinal column shortening distance (SCSD) measured on the 3D models (27.8 mm) were statistically shorter than those measured intraoperatively (32.8 mm) (P column strut graft than in those with bone-on-bone fusion (P column cannot represent that of the central spinal canal in patients with severe scoliosis. The spinal column shortening procedure in appropriately selected patient groups with bone-on-bone fusion is a viable option with the CCSD being significantly shorter than the convex SCSD. 4.

Total mandibular subapical osteotomy and Le Fort I osteotomy using piezosurgery and computer-aided designed and manufactured surgical splints: a favorable combination of three techniques in the management of severe mouth asymmetry in Parry-Romberg syndrome.

Science.gov (United States)

Scolozzi, Paolo; Herzog, Georges

2014-05-01

Although its pathogenesis remains obscure, Parry-Romberg syndrome (PRS) has been associated with the linear scleroderma en coup de sabre. PRS is characterized by unilateral facial atrophy of the skin, subcutaneous tissue, muscles, and bones with at least 1 dermatome supplied by the trigeminal nerve. Facial asymmetry represents the most common sequela and can involve the soft tissues, craniomaxillofacial skeleton, dentoalveolar area, and temporomandibular joint. Although orthognathic procedures have been reported for skeletal reconstruction, treatment of facial asymmetry has been directed to augmentation of the soft tissue volume on the atrophic side using different recontouring or volumetric augmentation techniques. Total mandibular subapical osteotomy has been used in the management of dentofacial deformities, such as open bite and mandibular dentoalveolar retrusion or protrusion associated with an imbalance between the lower lip and the chin. Management of orthognathic procedures has been improved by the recent introduction of stereolithographic surgical splints using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology and piezosurgery. Piezosurgery has increased security during surgery, especially for delicate procedures associated with a high risk of nerve injury. The present report describes a combined total mandibular subapical osteotomy and Le Fort I osteotomy using piezosurgery and surgical splints fabricated using CAD and CAM for the correction of severe mouth asymmetry related to vertical dentoalveolar disharmony in a patient with PRS. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dose conformation to the spine during palliative treatments using dynamic wedges

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Ormsby, Matthew A., E-mail: Matthew.Ormsby@usoncology.com [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States); Herndon, R. Craig; Kaczor, Joseph G. [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States)

2013-07-01

Radiation therapy is commonly used to alleviate pain associated with metastatic disease of the spine. Often, isodose lines are manipulated using dynamic or physical wedges to encompass the section of spine needing treatment while minimizing dose to normal tissue. We will compare 2 methods used to treat the entire thoracic spine. The first method treats the thoracic spine with a single, nonwedged posterior-anterior (PA) field. Dose is prescribed to include the entire spine. Isodose lines tightly conform to the top and bottom vertebrae, but vertebrae between these 2 received more than enough coverage. The second method uses a combination of wedges to create an isodose line that mimics the curvature of the thoracic spine. This “C”-shaped curvature is created by overlapping 2 fields with opposing dynamic wedges. Machine constraints limit the treatment length and therefore 2 isocenters are used. Each of the 2 PA fields contributes a portion of the total daily dose. This technique creates a “C”-shaped isodose line that tightly conforms to the thoracic spine, minimizing normal tissue dose. Spinal cord maximum dose is reduced, as well as mean dose to the liver, esophagus, and heart.

Comparison of the Modified McBride Procedure and the Distal Chevron Osteotomy for Mild to Moderate Hallux Valgus.

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Choi, Gi Won; Kim, Hak Jun; Kim, Taik Seon; Chun, Sung Kwang; Kim, Tae Wan; Lee, Yong In; Kim, Kyoung Ho

2016-01-01

Distal metatarsal osteotomy and the modified McBride procedure have each been used for the treatment of mild to moderate hallux valgus. However, few studies have compared the results of these 2 procedures for mild to moderate hallux valgus. The purpose of the present study was to compare the results of distal chevron osteotomy and the modified McBride procedure for treatment of mild to moderate hallux valgus according to the severity of the deformity. We analyzed the data from 45 patients (49.5%; 48 feet [49.0%]), who had undergone an isolated modified McBride procedure (McBride group), and 46 patients (50.5%; 50 feet [51.0%]), who had a distal chevron osteotomy (chevron group). We subdivided each group into those with mild and moderate deformity and compared the clinical and radiologic outcomes between the groups in relation to the severity of the deformity. The improvements in the American Orthopaedic Foot and Ankle Society scale score and the visual analog scale for pain were significantly better for the chevron group for both mild and moderate deformity. The chevron group experienced significantly greater correction in the hallux valgus angle and intermetatarsal angle for both mild and moderate deformity. The chevron group experienced a significantly greater decrease in the grade of sesamoid displacement for patients with moderate deformity. The McBride group had a greater risk of recurrence than did the chevron group for moderate deformity (odds ratio 14.00, 95% confidence interval 3.91 to 50.06, p hallux valgus recurrence than did the distal chevron group. Therefore, we recommend distal chevron osteotomy rather than a modified McBride procedure for the treatment of mild and moderate hallux valgus. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Use of a percutaneous osteotomy with plate fixation in hallux valgus correction.

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Díaz Fernández, Rodrigo

2017-09-20

With hundreds of operative methods described for correction of hallux valgus we can state that the ideal surgical treatment is still controversial. The Bösch technique has been used as a percutaneous way of correcting hallux valgus deformities with the use of a pin fixation. The aim of this study is to evaluate a new method of fixation by using a percutaneous locking plate. Between June 2013 and January 2015, 24 consecutive percutaneous subcapital osteotomies of the first metatarsal bone were performed for the treatment of painful hallux valgus deformities in 24 patients. Additional surgical procedures included DMMO's (Distal Metatarsal Minimally-Invasive Osteotomies) in 12 of the operated feet (44.44%); minor digits were corrected in 7 cases (25.9%). An Akin procedure was performed in 81% of cases and all cases underwent an adductor hallucis tenotomy. All patients were clinically assessed using the AOFAS score. Radiographic measures included the preoperative and postoperative values of the Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), and the Distal Metatarsal Articular Angle (DMAA). The mean correction achieved improved for AHV from 36.57±7.1 to 12.22±8.69°, for IMA from 13.8±1.59 to 7.08±2.72 and for DMAA from 13.98±7.38 to 6.07±4.99. Clinically, scores on the AOFAS scale improved from a 45.8±9.6 to 91.29±9.8. Although healing of the osteotomies was observed radiographically within 6 to 12 weeks, two cases (8.3%) exhibited delayed healing. There were no cases of nonunion. There were no superficial or deep infections or wound healing problems. Plate had to be removed in 3 cases (12.5%). This technique modification is an acceptable procedure to correct hallux valgus in patients with a moderate level of deformity. Level IV. Copyright © 2017 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

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

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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.

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

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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.

An IBEM solution to the scattering of plane SH-waves by a lined tunnel in elastic wedge space

Science.gov (United States)

Liu, Zhongxian; Liu, Lei

2015-02-01

The indirect boundary element method (IBEM) is developed to solve the scattering of plane SH-waves by a lined tunnel in elastic wedge space. According to the theory of single-layer potential, the scattered-wave field can be constructed by applying virtual uniform loads on the surface of lined tunnel and the nearby wedge surface. The densities of virtual loads can be solved by establishing equations through the continuity conditions on the interface and zero-traction conditions on free surfaces. The total wave field is obtained by the superposition of free field and scattered-wave field in elastic wedge space. Numerical results indicate that the IBEM can solve the diffraction of elastic wave in elastic wedge space accurately and efficiently. The wave motion feature strongly depends on the wedge angle, the angle of incidence, incident frequency, the location of lined tunnel, and material parameters. The waves interference and amplification effect around the tunnel in wedge space is more significant, causing the dynamic stress concentration factor on rigid tunnel and the displacement amplitude of flexible tunnel up to 50.0 and 17.0, respectively, more than double that of the case of half-space. Hence, considerable attention should be paid to seismic resistant or anti-explosion design of the tunnel built on a slope or hillside.

A computed tomography study in the location of greater palatine artery in South Indian population for maxillary osteotomy

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I Packiaraj

2016-01-01

Full Text Available Introduction: The greater palatine artery is one of the important feeding vessel to the maxilla. The surgeon should know the surgical anatomy of greater palatine artery to avoid trauma in maxilla which leads to ischemic problems. Aim: The CT evaluation of the distance between Pyriform aperture and the greater palatine foramen in various ages of both sexes. Result: The distance varies according to sex and age which are measured by CT and standardised. Discussion: The lateral nasal osteotomy can be done upto 25 mm depth, instead of 20 mm. Conclusion: By this study it shows that the lateral nasal wall osteotomy can be performed without injury to greater palatine artery.

Characterizing and configuring motorized wedge for a new generation telecobalt machine in a treatment planning system

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Kinhikar Rajesh

2007-01-01

Full Text Available A new generation telecobalt unit, Theratron Equinox-80, (MDS Nordion, Canada has been evaluated. It is equipped with a single 60-degree motorized wedge (MW, four universal wedges (UW for 150, 300, 450 and 600. MW was configured in Eclipse (Varian, Palo Alto, USA 3D treatment planning system (TPS. The profiles and central axis depth doses (CADD were measured with radiation field analyzer blue water phantom for MW. These profiles and CADD for MW were compared with UW in a homogeneous phantom generated in Eclipse for various field sizes. The absolute dose was measured for a field size of 10 x 10 cm2 only in a MEDTEC water phantom at 10 cm depth with a 0.13 cc thimble ion chamber (Scanditronix Wellhofer, Uppsala, Sweden and a NE electrometer (Nuclear Enterprises, UK. Measured dose with ion chamber was compared with the TPS predicted dose. MW angle was verified on the Equinox for four angles (15o, 30o, 45o and 60o. The variation in measured and calculated dose at 10 cm depth was within 2%. The measured and the calculated wedge angles were in well agreement within 2o. The motorized wedges were successfully configured in Eclipse for four wedge angles.

Comparison between innominate osteotomy and arthrodistraction as a primary treatment for Legg-Calvé-Perthes disease: a prospective controlled trial.

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Volpon, José Batista

2012-09-01

Legg-Calvé-Perthes (LCP) disease is currently managed by mechanical containment of the femoral head in the hip socket. As evidence suggests that hip distraction may offer a new treatment strategy, we used arthrodistraction as a primary treatment for active forms of LCP disease and prospectively compared the results with the Salter innominate osteotomy. A total of 54 children, six years or older of both genders with severe forms of LCP disease in the stages of necrosis or revascularisation, were enrolled. Patients were submitted to either Salter innominate osteotomy (n = 28) or hip arthrodistraction (n = 26). Final radiographs were used to evaluate the Mose index, Wiberg angle, extrusion index and the Stulberg et al. classification. There were no significant differences in gender, age, lateral pillar classification and average follow-up time between the two groups. The osteotomy group progressed without major complications, but children in the joint distraction group experienced episodes of pin tract pain and infection, leading to the early removal of the external device in one case. Two patients developed joint stiffness, treated by physiotherapy or manipulation, and one child developed subluxation of the femoral head. The average time in distraction was 4.44 months (2.53-7.23 months). In the final evaluation the osteotomy group showed better containment of the femoral head. The Mose index and the Stulberg et al. classification were statistically similar between the two groups. Despite similar final radiological results, arthrodistraction was associated with a higher morbidity. Consequently, we do not recommend hip distraction as a primary treatment for the early stages of LCP disease.

Approaches and perioperative management in periacetabular osteotomy surgery

DEFF Research Database (Denmark)

Søballe, Kjeld; Troelsen, Anders

2012-01-01

.9 to 8.1 years) of 209 PAOs performed using this approach have shown Kaplan-Meier survivorship rates of 94.7% at 5 years and 88.6% at 8.1 years, with conversion to total hip arthroplasty as the end point. Perioperative management includes a patient education program, optimized pain treatment strategies...... (local infiltration analgesia), and a progressive mobilization and exercise program. The transsartorial approach coupled with a specific perioperative management program has proved successful for PAO surgery.......In the early days of periacetabular osteotomy (PAO), surgical approaches were characterized by extensive soft-tissue dissection. The Smith-Petersen approach (and iliofemoral modifications) and the ilioinguinal approach have traditionally been used for PAO. The optimal surgical approach for PAO...

Piezosurgery versus Rotatory Osteotomy in Mandibular Impacted Third Molar Extraction

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Bhati, Bharat; Kukreja, Pankaj; Kumar, Sanjeev; Rathi, Vidhi C.; Singh, Kanika; Bansal, Shipra

2017-01-01

Aim: The aim of this study is to compare piezoelectric surgery versus rotatory osteotomy technique in removal of mandibular impacted third molar. Materials and Methods: Sample size of 30 patients 18 males, 12 females with a mean age of 27.43 ± 5.27. Bilateral extractions were required in all patients. All the patients were randomly allocated to two groups in one group, namely control group, surgical extraction of mandibular third molar was done using conventional rotatory osteotomy and in the other group, namely test group, extraction of lower third molar was done using Piezotome. Results: Parameters assessed in this study were – mouth opening (interincisal opening), pain (visual analog scale VAS score), swelling, incidence of dry socket, paresthesia and duration of surgery in both groups at baseline, 1st, 3rd, and 7th postoperative day. Comparing both groups pain scores with (P piezosurgery group (51.40 ± 17.9) minutes compared to the conventional rotatory group with a mean of (37.33 ± 15.5) minutes showing a statistically significant difference (P = 0.002). Conclusion: The main advantages of piezosurgery include soft tissue protection, optimal visibility in the surgical field, decreased blood loss, less vibration and noise, increased comfort for the patient, and protection of tooth structures. Therefore, the piezoelectric device was efficient in decreasing the short-term outcomes of pain and swelling although taking longer duration than conventional rotatory technique it significantly reduces the associated postoperative sequelae of third molar surgery. PMID:28713729

Biomechanical Analysis of Cuboid Osteotomy Lateral Column Lengthening for Stage II B Adult-Acquired Flatfoot Deformity: A Cadaveric Study.

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Zhou, Haichao; Ren, Haoyang; Li, Chunguang; Xia, Jiang; Yu, Guangrong; Yang, Yunfeng

2017-01-01

Purpose . To investigate the effect of cuboid osteotomy lateral column lengthening (LCL) for the correction of stage II B adult-acquired flatfoot deformity in cadaver. Methods . Six cadaver specimens were loaded to 350 N. Flatfoot models were established and each was evaluated radiographically and pedobarographically in the following conditions: (1) intact foot, (2) flatfoot, and (3) cuboid osteotomy LCL (2, 3, 4, and 5 mm). Results . Compared with the flatfoot model, the LCLs showed significant correction of talonavicular coverage on anteroposterior radiographs and talus-first metatarsal angle on both anteroposterior and lateral radiographs ( p stage II B adult-acquired flatfoot deformity with a 3 mm lengthening in cadavers.

Brachymetatarsia of the Fourth Metatarsal, Lengthening Scarf Osteotomy with Bone Graft

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Desai, Ankit; Lidder, Surjit; R. Armitage, Andrew; S. Rajaratnam, Samuel; D. Skyrme, Andrew

2013-01-01

A 16-year-old girl presented with left fourth metatarsal shortening causing significant psychological distress. She underwent lengthening scarf osteotomy held with an Omnitech® screw (Biotech International, France) with the addition of two 1 cm cancellous cubes (RTI Biologics, United States). A lengthening z-plasty of the extensor tendons and skin were also performed. At 6 weeks the patient was fully weight bearing and at one-year follow up, the patient was satisfied and discharged. A modifie...

Combined orthognathic distraction procedure: Le Fort I maxillary osteotomy and mandibular curvilinear distraction osteogenesis. A new technique for craniofacial management.

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Schendel, Stephen A; Hazan-Molina, Hagai; Aizenbud, Dror

2014-04-01

Dentofacial deformities are traditionally treated by maxillary and mandibular osteotomies conducted separately or simultaneously. Recently, distraction osteogenesis has become an irreplaceable part of the surgical armamentarium, for its ability to induce new bone formation between the surfaces of bone segments that are gradually separated by incremental traction, along with a simultaneous expansion of the surrounding soft-tissue envelope. The aim of this article is to describe a combined surgical technique consisting of simultaneous maxillary Le Fort I advancement and mandibular surgical repositioning by means of bilateral sagittal split osteotomy with a curvilinear distractor based on a preliminary computerized presurgical prediction.

Preliminary results of an anteverting triple periacetabular osteotomy for the treatment of hip instability in Down syndrome.

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Maranho, D A; Kim, Y-J; Williams, K A; Novais, E N

2018-02-01

To investigate the outcomes of an anteverting triple periacetabular osteotomy for the treatment of hip instability in skeletally immature patients with Down syndrome. We evaluated 16 patients (21 hips) with Down syndrome and hip instability who underwent an anteverting triple periacetabular osteotomy between 2007 and 2016. There were nine females and seven males with an average age of 7.4 years SD 2.0. We assessed the level of hip pain, gait ability and clinical stability at a minimum of one year after surgery. Radiographic evaluation included pre- and postoperative lateral centre-edge angle (LCEA), Tönnis acetabular angle and extrusion index. After an average follow-up of 4.1 years SD 2.6, 20 of 21 hips (95%) remained clinically stable. In all, 12 of 16 (75%) patients had a full gait without a major limp, but three patients (19%) had a persistent limp. Of the 21 procedures, one hip (5%) was considered a failure due to persistent instability. There was a mean increase of 18.3º SD 15.3º of the LCEA (p treatment of an infection; which was considered a major complication. The anteverting triple periacetabular osteotomy provided global deformity correction and achieved hip stability in 95% of the hips after a mean follow-up of 4.1 years. Therapeutic level IV.

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

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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