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

    Hoffman, Andrew

    2002-01-01

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

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

    Hoffman, Andrew

    2004-01-01

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

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

    Hoffman, Andrew

    2003-01-01

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

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

    2006-12-01

    MRI confirmed a large coexisting haemangioma which may have confounded perception of stress fracture symptoms. Table 1 is a comprehensive subject...Johnson JR, Light KI, Yuan HA: A double-blind study of capacitively coupled electrical stimulation as an adjunct to lumbar spinal fusions. Spine 24...Simmons JW, Jr., Mooney V, Thacker I: Pseudarthrosis after lumbar spine fusion: nonoperative salvage with pulsed electromagnetic fields. Am J

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

    Fournier, Pierre-Etienne

    2003-06-01

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

  6. Medial tibial stress syndrome.

    Reshef, Noam; Guelich, David R

    2012-04-01

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

  7. Characterizing the Learning Effect in Response to Biofeedback Aimed at Reducing Tibial Acceleration during Running

    Linda M. A. van Gelder

    2018-02-01

    Full Text Available Increased tibial acceleration has been found to be an important risk factor for tibial stress fractures. Interventions aimed at reducing this variable which found a beneficial effect include the use of biofeedback in gait retraining. However, no studies have focused on the time participants take to modify tibial acceleration, therefore we aimed to find the start of a learning plateau in this study. Six participants ran on a treadmill while multisensory feedback was given. A single-subject analysis was used to characterise the learning effects. All participants changed peak tibial acceleration within the first step of running in the feedback condition. Two participants further reduced tibial acceleration to reach a plateau within 120 steps. In four of the six participants a strong effect of the feedback was still present after a week. Further research is needed to optimise the use of biofeedback in reducing the prevalence of tibial stress fractures.

  8. Medial tibial stress syndrome: a critical review

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

    2009-01-01

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

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

    Couture, Christopher J.; Karlson, Kristine A.

    2002-01-01

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

  10. Bone stress in runners with tibial stress fracture.

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

    2015-11-01

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

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

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

  12. Medial tibial stress syndrome: a critical review.

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

    2009-01-01

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

  13. Acute changes in foot strike pattern and cadence affect running parameters associated with tibial stress fractures.

    Yong, Jennifer R; Silder, Amy; Montgomery, Kate L; Fredericson, Michael; Delp, Scott L

    2018-05-18

    Tibial stress fractures are a common and debilitating injury that occur in distance runners. Runners may be able to decrease tibial stress fracture risk by adopting a running pattern that reduces biomechanical parameters associated with a history of tibial stress fracture. The purpose of this study was to test the hypothesis that converting to a forefoot striking pattern or increasing cadence without focusing on changing foot strike type would reduce injury risk parameters in recreational runners. Running kinematics, ground reaction forces and tibial accelerations were recorded from seventeen healthy, habitual rearfoot striking runners while running in their natural running pattern and after two acute retraining conditions: (1) converting to forefoot striking without focusing on cadence and (2) increasing cadence without focusing on foot strike. We found that converting to forefoot striking decreased two risk factors for tibial stress fracture: average and peak loading rates. Increasing cadence decreased one risk factor: peak hip adduction angle. Our results demonstrate that acute adaptation to forefoot striking reduces different injury risk parameters than acute adaptation to increased cadence and suggest that both modifications may reduce the risk of tibial stress fractures. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

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

    1982-01-01

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

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

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

    2015-09-01

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

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

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

  17. Biomechanical Factors in Tibial Stress Fracture

    2001-08-01

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

  18. Contact Stress Generation on the UHMWPE Tibial Insert

    S. Petrović Savić

    2014-12-01

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

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

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

    2017-01-01

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

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

    Winters, M.

    2017-01-01

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

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

    Moen, M.H.

    2012-01-01

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

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

    Moen, M.H.

    2012-01-01

    The work contained is this thesis discusses aetiology, imaging and treatment of a common leg injury: medial tibial stress syndrome (MTSS). Although a common injury, the number of scientific articles on this topic is relatively low as is explained in chapter 1. This chapter also highlights that the most probable cause of MTSS is bone overload and not traction induced periostitis. In chapter 2 a review of the literature on MTSS is provided until 2009. Chapters 3 and 4 discuss different common a...

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

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

    2017-06-18

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

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

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

    2017-08-01

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

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

    Mammoto Takeo

    2012-05-01

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

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

    2012-01-01

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

  7. Epidemiology of metatarsal stress fractures versus tibial and femoral stress fractures during elite training.

    Finestone, Aharon; Milgrom, Charles; Wolf, Omer; Petrov, Kaloyan; Evans, Rachel; Moran, Daniel

    2011-01-01

    The training of elite infantry recruits takes a year or more. Stress fractures are known to be endemic in their basic training and the clinical presentation of tibial, femoral, and metatarsal stress fractures are different. Stress fracture incidence during the subsequent progressively more demanding training is not known. The study hypothesis was that after an adaptation period, the incidence of stress fractures during the course of 1 year of elite infantry training would fall in spite of the increasingly demanding training. Seventy-six male elite infantry recruits were followed for the development of stress fractures during a progressively more difficult training program composed of basic training (1 to 14 weeks), advanced training (14 to 26 weeks), and unit training (26 to 52 weeks). Subjects were reviewed regularly and those with clinical suspicion of stress fracture were assessed using bone scan and X-rays. The incidence of stress fractures was 20% during basic training, 14% during advanced training and 23% during unit training. There was a statistically significant difference in the incidence of tibial and femoral stress fractures versus metatarsal stress fractures before and after the completion of phase II training at week 26 (p=0.0001). Seventy-eight percent of the stress fractures during phases I and II training were either tibial or femoral, while 91% of the stress fractures in phase III training were metatarsal. Prior participation in ball sports (p=0.02) and greater tibial length (p=0.05) were protective factors for stress fracture. The study hypothesis that after a period of soldier adaptation, the incidence of stress fractures would decrease in spite of the increasingly demanding elite infantry training was found to be true for tibial and femoral fractures after 6 months of training but not for metatarsal stress fractures. Further studies are required to understand the mechanism of this difference but physicians and others treating stress fractures

  8. Effect of step width manipulation on tibial stress during running.

    Meardon, Stacey A; Derrick, Timothy R

    2014-08-22

    Narrow step width has been linked to variables associated with tibial stress fracture. The purpose of this study was to evaluate the effect of step width on bone stresses using a standardized model of the tibia. 15 runners ran at their preferred 5k running velocity in three running conditions, preferred step width (PSW) and PSW±5% of leg length. 10 successful trials of force and 3-D motion data were collected. A combination of inverse dynamics, musculoskeletal modeling and beam theory was used to estimate stresses applied to the tibia using subject-specific anthropometrics and motion data. The tibia was modeled as a hollow ellipse. Multivariate analysis revealed that tibial stresses at the distal 1/3 of the tibia differed with step width manipulation (p=0.002). Compression on the posterior and medial aspect of the tibia was inversely related to step width such that as step width increased, compression on the surface of tibia decreased (linear trend p=0.036 and 0.003). Similarly, tension on the anterior surface of the tibia decreased as step width increased (linear trend p=0.029). Widening step width linearly reduced shear stress at all 4 sites (pstresses experienced by the tibia during running were influenced by step width when using a standardized model of the tibia. Wider step widths were generally associated with reduced loading of the tibia and may benefit runners at risk of or experiencing stress injury at the tibia, especially if they present with a crossover running style. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Fonseca, Fernando; Rebelo, Edgar; Completo, Antonio

    2011-01-01

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

  10. A 3D finite element model to investigate prosthetic interface stresses of different posterior tibial slope.

    Shen, Yi; Li, Xiaomiao; Fu, Xiaodong; Wang, Weili

    2015-11-01

    Posterior tibial slope that is created during proximal tibial resection in total knee arthroplasty has emerged as an important factor in the mechanics of the knee joint and the surgical outcome. But the ideal degree of posterior tibial slope for recovery of the knee joint function and preventions of complications remains controversial and should vary in different racial groups. The objective of this paper is to investigate the effects of posterior tibial slope on contact stresses in the tibial polyethylene component of total knee prostheses. Three-dimensional finite element analysis was used to calculate contact stresses in tibial polyethylene component of total knee prostheses subjected to a compressive load. The 3D finite element model of total knee prosthesis was constructed from the images produced by 3D scanning technology. Stresses in tibial polyethylene component were calculated with four different posterior tibial slopes (0°, 3°, 6° and 9°). The 3D finite element model of total knee prosthesis we presented was well validated. We found that the stress distribution in the polythene as evaluated by the distributions of the von Mises stress, the maximum principle stress, the minimum principle stress and the Cpress were more uniform with 3° and 6° posterior tibial slopes than with 0° and 9° posterior tibial slopes. Moreover, the peaks of the above stresses and trends of changes with increasing degree of knee flexion were more ideal with 3° and 6° posterior slopes. The results suggested that the tibial component inclination might be favourable to 7°-10° so far as the stress distribution is concerned. The range of the tibial component inclination also can decrease the wear of polyethylene. Chinese posterior tibial slope is bigger than in the West, and the current domestic use of prostheses is imported from the West, so their demands to tilt back bone cutting can lead to shorten the service life of prostheses; this experiment result is of important

  11. Accelerated tibial fracture union in the third trimester of pregnancy: a case report

    Ahmad Mudussar A

    2008-02-01

    Full Text Available Abstract Introduction We present a case of accelerated tibial fracture union in the third trimester of pregnancy. This is of particular relevance to orthopaedic surgeons, who must be made aware of the potentially accelerated healing response in pregnancy and the requirement for prompt treatment. Case presentation A 40 year old woman at 34 weeks gestational age sustained a displaced fracture of the tibial shaft. This was initially treated conservatively in plaster with view to intra-medullary nailing postpartum. Following an emergency caesarean section, the patient was able to fully weight bear without pain 4 weeks post injury, indicating clinical union. Radiographs demonstrated radiological union with good alignment and abundant callus formation. Fracture union occurred within 4 weeks, less than half the time expected for a conservatively treated tibial shaft fracture. Conclusion Long bone fractures in pregnancy require clear and precise management plans as fracture healing is potentially accelerated. Non-operative treatment is advisable provided satisfactory alignment of the fracture is achieved.

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

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

    2013-06-01

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

  13. Immediate effects of modified landing pattern on a probabilistic tibial stress fracture model in runners.

    Chen, T L; An, W W; Chan, Z Y S; Au, I P H; Zhang, Z H; Cheung, R T H

    2016-03-01

    Tibial stress fracture is a common injury in runners. This condition has been associated with increased impact loading. Since vertical loading rates are related to the landing pattern, many heelstrike runners attempt to modify their footfalls for a lower risk of tibial stress fracture. Such effect of modified landing pattern remains unknown. This study examined the immediate effects of landing pattern modification on the probability of tibial stress fracture. Fourteen experienced heelstrike runners ran on an instrumented treadmill and they were given augmented feedback for landing pattern switch. We measured their running kinematics and kinetics during different landing patterns. Ankle joint contact force and peak tibial strains were estimated using computational models. We used an established mathematical model to determine the effect of landing pattern on stress fracture probability. Heelstrike runners experienced greater impact loading immediately after landing pattern switch (Ptibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986). Immediate transitioning of the landing pattern in heelstrike runners may not offer timely protection against tibial stress fracture, despite a reduction of impact loading. Long-term effects of landing pattern switch remains unknown. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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

    2017-12-01

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

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

    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.

  16. Ground reaction forces and bone parameters in females with tibial stress fracture.

    Bennell, Kim; Crossley, Kay; Jayarajan, Jyotsna; Walton, Elizabeth; Warden, Stuart; Kiss, Z Stephen; Wrigley, Tim

    2004-03-01

    Tibial stress fracture is a common overuse running injury that results from the interplay of repetitive mechanical loading and bone strength. This research project aimed to determine whether female runners with a history of tibial stress fracture (TSF) differ in ground reaction force (GRF) parameters during running, regional bone density, and tibial bone geometry from those who have never sustained a stress fracture (NSF). Thirty-six female running athletes (13 TSF; 23 NSF) ranging in age from 18 to 44 yr were recruited for this cross-sectional study. The groups were well matched for demographic, training, and menstrual parameters. A force platform measured selected GRF parameters (peak and time to peak for vertical impact and active forces, and horizontal braking and propulsive forces) during overground running at 4.0 m.s.(-1). Lumbar spine, proximal femur, and distal tibial bone mineral density were assessed by dual energy x-ray absorptiometry. Tibial bone geometry (cross-sectional dimensions and areas, and second moments of area) was calculated from a computerized tomography scan at the junction of the middle and distal thirds. There were no significant differences between the groups for any of the GRF, bone density, or tibial bone geometric parameters (P > 0.05). Both TSF and NSF subjects had bone density levels that were average or above average compared with a young adult reference range. Factor analysis followed by discriminant function analysis did not find any combinations of variables that differentiated between TSF and NSF groups. These findings do not support a role for GRF, bone density, or tibial bone geometry in the development of tibial stress fractures, suggesting that other risk factors were more important in this cohort of female runners.

  17. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments

    Franklyn, Melanie; Oakes, Barry

    2015-01-01

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imagin...

  18. Effect of the Fatigue Induced by a 110-km Ultramarathon on Tibial Impact Acceleration and Lower Leg Kinematics.

    Marlene Giandolini

    Full Text Available Ultramarathon runners are exposed to a high number of impact shocks and to severe neuromuscular fatigue. Runners may manage mechanical stress and muscle fatigue by changing their running kinematics. Our purposes were to study (i the effects of a 110-km mountain ultramarathon (MUM on tibial shock acceleration and lower limb kinematics, and (ii whether kinematic changes are modulated according to the severity of neuromuscular fatigue. Twenty-three runners participated in the study. Pre- and post-MUM, neuromuscular tests were performed to assess knee extensor (KE and plantar flexor (PF central and peripheral fatigue, and a treadmill running bouts was completed during which step frequency, peak acceleration, median frequency and impact frequency content were measured from tibial acceleration, as well as foot-to-treadmill, tibia-to-treadmill, and ankle flexion angles at initial contact, and ankle range of motion using video analysis. Large neuromuscular fatigue, including peripheral changes and deficits in voluntary activation, was observed in KE and PF. MVC decrements of ~35% for KE and of ~28% for PF were noted. Among biomechanical variables, step frequency increased by ~2.7% and the ankle range of motion decreased by ~4.1% post-MUM. Runners adopting a non rearfoot strike pre-MUM adopted a less plantarflexed foot strike pattern post-MUM while those adopting a rearfoot strike pre-MUM tended to adopt a less dorsiflexed foot strike pattern post-MUM. Positive correlations were observed between percent changes in peripheral PF fatigue and the ankle range of motion. Peripheral PF fatigue was also significantly correlated to both percent changes in step frequency and the ankle angle at contact. This study suggests that in a fatigued state, ultratrail runners use compensatory/protective adjustments leading to a flatter foot landing and this is done in a fatigue dose-dependent manner. This strategy may aim at minimizing the overall load applied to the

  19. Tibial stress fractures in racing Standardbreds: 13 cases (1989-1993)

    Ruggles, A.J.; Moore, R.M.; Bertone, A.L.; Schneider, R.K.; Bailey, M.Q.

    1996-01-01

    To determine clinical signs, radiographic and scintigraphic findings, and performance outcome of racing Standardbreds with tibial stress fractures. Retrospective case series. 13 racing Standardbreds with tibial stress fractures. Information concerning clinical signs, diagnostic evaluation, and recommendations was obtained by review of the medical records. Performance information before and after diagnosis of the fracture was collected from racing records, and follow-up information was obtained from the owners or trainers by use of a telephone questionnaire. Horses with tibial stress fractures were moderately lame, and diagnosis was made by nuclear scintigraphy and radiography. Fractures were more likely to occur in 2-year-old horses than in older horses. The fracture location was unique for Standardbreds; 11 of 13 developed stress fractures in the mid-diaphysis of the tibia, whereas fractures in Thoroughbreds are usually in the proximal caudal or caudolateral cortex. Fractures occurred in young horses that had raced or were in advanced race training. All horses were treated with rest alone, and 10 of 13 horses raced after injury. The horses that raced after injury were able to return to a level of performance that was equal to or better than the level raced before injury. 8 of 10 horses established a lifetime-best winning time after injury. Tibial stress fractures are a cause of lameness in young racing Standardbreds. Diagnosis is aided by nuclear scintigraphy. The prognosis for return to previous level of performance after a tibial stress fracture is good

  20. Etiologic factors in the development of medial tibial stress syndrome: a review of the literature.

    Tweed, Jo L; Avil, Steven J; Campbell, Jackie A; Barnes, Mike R

    2008-01-01

    Medial tibial stress syndrome is a type of exercise-induced leg pain that is common in recreational and competitive athletes. Although various studies have attempted to find the exact pathogenesis of this common condition, it remains unknown. Various theories in literature from 1976 to 2006 were reviewed using key words. Until recently, inflammation of the periosteum due to excessive traction was thought to be the most likely cause of medial tibial stress syndrome. This periostitis has been hypothesized by some authors to be caused by the tearing away of the muscle fibers at the muscle-bone interface, although there are several suggestions as to which, if any, muscle is responsible. Recent studies have supported the view that medial tibial stress syndrome is not an inflammatory process of the periosteum but instead a stress reaction of bone that has become painful.

  1. Distinct hip and rearfoot kinematics in female runners with a history of tibial stress fracture.

    Milner, Clare E; Hamill, Joseph; Davis, Irene S

    2010-02-01

    Cross-sectional controlled laboratory study. To investigate the kinematics of the hip, knee, and rearfoot in the frontal and transverse planes in female distance runners with a history of tibial stress fracture. Tibial stress fractures are a common overuse injury in runners, accounting for up to half of all stress fractures. Abnormal kinematics of the lower extremity may contribute to abnormal musculoskeletal load distributions, leading to an increased risk of stress fractures. Thirty female runners with a history of tibial stress fracture were compared to 30 age-matched and weekly-running-distance-matched control subjects with no previous lower extremity bony injuries. Kinematic and kinetic data were collected using a motion capture system and a force platform, respectively, as subjects ran in the laboratory. Selected variables of interest were compared between the groups using a multivariate analysis of variance (MANOVA). Peak hip adduction and peak rearfoot eversion angles were greater in the stress fracture group compared to the control group. Peak knee adduction and knee internal rotation angles and all joint angles at impact peak were similar between the groups. Runners with a previous tibial stress fracture exhibited greater peak hip adduction and rearfoot eversion angles during the stance phase of running compared to healthy controls. A consequence of these mechanics may be altered load distribution within the lower extremity, predisposing individuals to stress fracture.

  2. Chronic shin splints. Classification and management of medial tibial stress syndrome.

    Detmer, D E

    1986-01-01

    A clinical classification and treatment programme has been developed for chronic medial tibial stress syndrome. Medial tibial stress syndrome has been reported to be either tibial stress fracture or microfracture, tibial periostitis, or distal deep posterior chronic compartment syndrome. Three chronic types exist and may coexist: Type I (tibial microfracture, bone stress reaction or cortical fracture); type II (periostalgia from chronic avulsion of the periosteum at the periosteal-fascial junction); and type III (chronic compartment syndrome syndrome). Type I disease is treated nonoperatively. Operations for resistant types II and III medial tibial stress syndrome were performed in 41 patients. Bilaterality was common (type II, 50% type III, 88%). Seven had coexistent type II/III; one had type I/II. Preoperative symptoms averaged 24 months in type II, 6 months in type III, and 33 months in types II/III. Mean age was 22 years (15 to 51). Resting compartment pressures were normal in type II (mean 12 mm Hg) and elevated in type III and type II/III (mean 23 mm Hg). Type II and type II/III patients received fasciotomy plus periosteal cauterisation. Type III patients had fasciotomy only. All procedures were performed on an outpatient basis using local anaesthesia. Follow up was complete and averaged 6 months (2 to 14 months). Improved performance was as follows: type II, 93%, type III, 100%; type II/III, 86%. Complete cures were as follows: type II, 78%; type III, 75%; and type II/III, 57%. This experience suggests that with precise diagnosis and treatment involving minimal risk and cost the athlete has a reasonable chance of return to full activity.

  3. Bilateral periprosthetic tibial stress fracture after total knee arthroplasty: A case report.

    Ozdemir, Guzelali; Azboy, Ibrahim; Yilmaz, Baris

    2016-01-01

    Periprosthetic fractures around the knee after total knee arthroplasty can be seen in the femur, tibia and patella. The tibial fractures are rare cases. Our case with bilateral tibial stress fracture developed after total knee arthroplasty (TKA) is the first of its kind in the literature. 75-year-old male patient with bilateral knee osteoarthritis had not benefited from conservative treatment methods previously applied. Left TKA was applied. In the second month postoperatively, periprosthetic tibial fracture was identified and osteosynthesis was implemented with locked tibia proximal plate-screw. Bone union in 12 weeks was observed in his follow-ups. After 15 months of his first operation, TKA was applied to the right knee. Postoperatively in the second month, as in the first operation, periprosthetic tibial fracture was detected. Osteosynthesis with locking plate-screw was applied and union in 12 weeks was observed in his follow-up. He was seen mobilized independently and without support in the last control of the case made in the 24th month after the second operation. The number of TKA applications is expected to increase in the future. The incidence of periprosthetic fractures should also be expected to increase in these cases. Periprosthetic tibial fractures after TKA are rarely seen. The treatment of periprosthetic fractures around the knee after TKA can be difficult. In the case of persistent pain in the upper end of the tibia after the surgery, stress fracture should be considered. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Surgical treatment of refractory tibial stress fractures in elite dancers: a case series.

    Miyamoto, Ryan G; Dhotar, Herman S; Rose, Donald J; Egol, Kenneth

    2009-06-01

    Treatment of tibial stress fractures in elite dancers is centered on rest and activity modification. Surgical intervention in refractory cases has important implications affecting the dancers' careers. Refractory tibial stress fractures in dancers can be treated successfully with drilling and bone grafting or intramedullary nailing. Case series; Level of evidence, 4. Between 1992 and 2006, 1757 dancers were evaluated at a dance medicine clinic; 24 dancers (1.4%) had 31 tibial stress fractures. Of that subset, 7 (29.2%) elite dancers with 8 tibial stress fractures were treated operatively with either intramedullary nailing or drilling and bone grafting. Six of the patients were followed up closely until they were able to return to dance. One patient was available only for follow-up phone interview. Data concerning their preoperative treatment regimens, operative procedures, clinical union, radiographic union, and time until return to dance were recorded and analyzed. The mean age of the surgical patients at the time of stress fracture was 22.6 years. The mean duration of preoperative symptoms before surgical intervention was 25.8 months. Four of the dancers were male and 3 were female. All had failed nonoperative treatment regimens. Five patients (5 tibias) underwent drilling and bone grafting of the lesion, and 2 patients (3 tibias) with completed fractures or multiple refractory stress fractures underwent intramedullary nailing. Clinical union was achieved at a mean of 6 weeks and radiographic union at 5.1 months. Return to full dance activity was at an average of 6.5 months postoperatively. Surgical intervention for tibial stress fractures in dancers who have not responded to nonoperative management allowed for resolution of symptoms and return to dancing with minimal morbidity.

  5. Medial tibial stress syndrome can be diagnosed reliably using history and physical examination

    Winters, M.; Bakker, E. W. P.; Moen, M. H.; Barten, C. C.; Teeuwen, R.; Weir, A.

    2017-01-01

    The majority of sporting injuries are clinically diagnosed using history and physical examination as the cornerstone. There are no studies supporting the reliability of making a clinical diagnosis of medial tibial stress syndrome (MTSS). Our aim was to assess if MTSS can be diagnosed reliably, using

  6. Section modulus is the optimum geometric predictor for stress fractures and medial tibial stress syndrome in both male and female athletes.

    Franklyn, Melanie; Oakes, Barry; Field, Bruce; Wells, Peter; Morgan, David

    2008-06-01

    Various tibial dimensions and geometric parameters have been linked to stress fractures in athletes and military recruits, but many mechanical parameters have still not been investigated. Sedentary people, athletes with medial tibial stress syndrome, and athletes with stress fractures have smaller tibial geometric dimensions and parameters than do uninjured athletes. Cohort study; Level of evidence, 3. Using a total of 88 subjects, male and female patients with either a tibial stress fracture or medial tibial stress syndrome were compared with both uninjured aerobically active controls and uninjured sedentary controls. Tibial scout radiographs and cross-sectional computed tomography images of all subjects were scanned at the junction of the midthird and distal third of the tibia. Tibial dimensions were measured directly from the films; other parameters were calculated numerically. Uninjured exercising men have a greater tibial cortical cross-sectional area than do their sedentary and injured counterparts, resulting in a greater value of some other cross-sectional geometric parameters, particularly the section modulus. However, for women, the cross-sectional areas are either not different or only marginally different, and there are few tibial dimensions or geometric parameters that distinguish the uninjured exercisers from the sedentary and injured subjects. In women, the main difference between the groups was the distribution of cortical bone about the centroid as a result of the different values of section modulus. Last, medial tibial stress syndrome subjects had smaller tibial cross-sectional dimensions than did their uninjured exercising counterparts, suggesting that medial tibial stress syndrome is not just a soft-tissue injury but also a bony injury. The results show that in men, the cross-sectional area and the section modulus are the key parameters in the tibia to distinguish exercise and injury status, whereas for women, it is the section modulus only.

  7. Quantitative analysis of scintigraphic findings in tibial stress fractures in Thoroughbred racehorses.

    Valdés-Martínez, Alejandro; Seiler, Gabriela; Mai, Wilfried; Bolt, David M; Mudge, Margaret; Dukti, Sarah A; Hubert, Jeremy D

    2008-07-01

    To develop a quantitative method of interpreting tibial scintigrams of Thoroughbred racehorses with tibial stress fractures that may facilitate diagnosis of fractures and to provide prognostic information regarding future performance of affected horses. 35 Thoroughbred racehorses. Static bone-phase scintigrams of tibial stress fractures were quantitatively analyzed by use of ratios of the mean radionuclide counts per pixel in a region of interest (ROI) drawn around the area of increased uptake of radiopharmaceutical to mean counts per pixel in a second ROI drawn around an apparently normal area of the tibial diaphysis. In horses with unilateral fractures, ratios for the contralateral tibia were determined by use of 2 ROIs drawn at the same positions as the ROIs in the fractured tibia. Ratios were compared between fractured versus apparently normal tibias, between horses that returned to racing versus those that did not, and among horses with various grades of lameness. The association between ratios for fractured tibias and intervals between diagnosis and return to racing was also assessed. Mean ratio of ROIs in apparently normal tibias was 1.35 (95% confidence interval [CI], 1.21 to 1.50); that in tibias with stress fractures was 3.55 (95% CI, 2.50 to 4.60). These ratios were significantly different. None of the associations between ratios for fractured tibias and grades of lameness or performance outcomes were significant. Tibial stress fracture scintigrams can be quantitatively analyzed. A prospective study with a controlled rehabilitation period is necessary to evaluate the possible applications of this method.

  8. Sequential Proximal Tibial Stress Fractures associated with Prolonged usage of Methotrexate and Corticosteroids: A Case Report

    Tan TJL

    2015-11-01

    Full Text Available Stress fractures of the proximal tibia metaphysis are rare in the elderly. We present a case of a 65-year old male who developed sequential proximal tibia stress fractures associated with prolonged usage of methotrexate and prednisolone within a span of 18 months. Magnetic Resonance Imaging revealed an incomplete stress fracture involving the medial proximal tibial region. The patient was treated with stemmed total knee arthroplasty (TKA bilaterally. Stress fractures should be considered in patients with atypical knee pain who have a history of methotrexate and prednisolone usage. TKA is an effective treatment in stress fractures of the proximal tibia.

  9. Spontaneous osteonecrosis of the knee associated with tibial plateau and femoral condyle insufficiency stress fracture

    Narvaez, J.A.; Narvaez, J.; Lama, E.De; Sanchez, A. [Department of Magnetic Resonance Imaging, IDI Hospital Duran i Reynals, Ciutat Sanitaria i Universitaria de Bellvitge, Gran Via s/n, 08907, L' Hospitalet de Llobregat (Barcelona) (Spain)

    2003-08-01

    The purpose of this article is to describe the association between spontaneous osteonecrosis and insufficiency stress fractures of the knee. To determine whether insufficiency stress fracture is associated with spontaneous osteonecrosis of the knee, we retrospectively reviewed the medical charts and imaging studies of all patients with spontaneous osteonecrosis of the knee, studied by MR imaging, seen in a tertiary hospital over an 8-year period. Four women (age range 66-84 years) presented spontaneous osteonecrosis of the knee associated with insufficiency stress fracture of the medial tibial plateau. One of these patients also presented a concomitant insufficiency stress fracture of the medial femoral condyle. Radiographs were diagnostic of spontaneous osteonecrosis of the medial femoral condyle in three cases, and insufficiency stress fracture of the medial tibial plateau was detected in one case. Magnetic resonance imaging allows the diagnosis of both conditions in all four cases. Spontaneous osteonecrosis of the knee may be associated with insufficiency stress fracture of the medial femoral condyle and the medial tibial plateau. This association provides additional arguments in favor of the traumatic etiology of spontaneous osteonecrosis of knee. (orig.)

  10. Spontaneous osteonecrosis of the knee associated with tibial plateau and femoral condyle insufficiency stress fracture

    Narvaez, J.A.; Narvaez, J.; Lama, E.De; Sanchez, A.

    2003-01-01

    The purpose of this article is to describe the association between spontaneous osteonecrosis and insufficiency stress fractures of the knee. To determine whether insufficiency stress fracture is associated with spontaneous osteonecrosis of the knee, we retrospectively reviewed the medical charts and imaging studies of all patients with spontaneous osteonecrosis of the knee, studied by MR imaging, seen in a tertiary hospital over an 8-year period. Four women (age range 66-84 years) presented spontaneous osteonecrosis of the knee associated with insufficiency stress fracture of the medial tibial plateau. One of these patients also presented a concomitant insufficiency stress fracture of the medial femoral condyle. Radiographs were diagnostic of spontaneous osteonecrosis of the medial femoral condyle in three cases, and insufficiency stress fracture of the medial tibial plateau was detected in one case. Magnetic resonance imaging allows the diagnosis of both conditions in all four cases. Spontaneous osteonecrosis of the knee may be associated with insufficiency stress fracture of the medial femoral condyle and the medial tibial plateau. This association provides additional arguments in favor of the traumatic etiology of spontaneous osteonecrosis of knee. (orig.)

  11. Accelerated Stress-Corrosion Testing

    1986-01-01

    Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.

  12. Inverse relationship between the complexity of midfoot kinematics and muscle activation in patients with medial tibial stress syndrome

    Rathleff, M S; Samani, Afshin; Olesen, C G

    2011-01-01

    Medial tibial stress syndrome is a common overuse injury characterized by pain located on the medial side of the lower leg during weight bearing activities such as gait. The purpose of this study was to apply linear and nonlinear methods to compare the structure of variability of midfoot kinematics...... and surface electromyographic (SEMG) signals between patients with medial tibial stress syndrome and healthy controls during gait. Fourteen patients diagnosed with medial tibial stress syndrome and 11 healthy controls were included from an orthopaedic clinic. SEMG from tibialis anterior and the soleus muscles...... as well as midfoot kinematics were recorded during 20 consecutive gait cycles. Permuted sample entropy and permutation entropy were used as a measure of complexity from SEMG signals and kinematics. SEMG signals in patients with medial tibial stress syndrome were characterized by higher structural...

  13. Construction of finite element model and stress analysis of anterior cruciate ligament tibial insertion.

    Dai, Can; Yang, Liu; Guo, Lin; Wang, Fuyou; Gou, Jingyue; Deng, Zhilong

    2015-01-01

    The aim of the present study was to develop a more realistic finite element (FE) model of the human anterior cruciate ligament (ACL) tibial insertion and to analyze the stress distribution in the ACL internal fibers under load. The ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software and saved as ".hmascii" file. This document was imported into HyperMesh software. The solid mesh model generated using HyperMesh software was imported into Abaqus software. The material properties were introduced, boundary conditions were set, and load was added to carry out the FE analysis. The stress distribution of the ACL internal fibers was uneven. The lowest stress could be observed in the ACL lateral fibers under tensile and shear load. The establishment of ACL tibial insertion FE model and mechanical analysis could reveal the stress distribution in the ACL internal fibers under load. There was greater load carrying capacity in the ACL lateral fibers which could sustain greater tensile and shear forces.

  14. Influence of outdoor running fatigue and medial tibial stress syndrome on accelerometer-based loading and stability.

    Schütte, Kurt H; Seerden, Stefan; Venter, Rachel; Vanwanseele, Benedicte

    2018-01-01

    Medial tibial stress syndrome (MTSS) is a common overuse running injury with pathomechanics likely to be exaggerated by fatigue. Wearable accelerometry provides a novel alternative to assess biomechanical parameters continuously while running in more ecologically valid settings. The purpose of this study was to determine the influence of outdoor running fatigue and MTSS on both dynamic loading and dynamic stability derived from trunk and tibial accelerometery. Runners with (n=14) and without (n=16) history of MTSS performed an outdoor fatigue run of 3200m. Accelerometer-based measures averaged per lap included dynamic loading of the trunk and tibia (i.e. axial peak positive acceleration, signal power magnitude, and shock attenuation) as well as dynamic trunk stability (i.e. tri-axial root mean square ratio, step and stride regularity, and sample entropy). Regression coefficients from generalised estimating equations were used to evaluate group by fatigue interactions. No evidence could be found for dynamic loading being higher with fatigue in runners with MTSS history (all measures p>0.05). One significant group by running fatigue interaction effect was detected for dynamic stability. Specifically, in MTSS only, decreases mediolateral sample entropy i.e. loss of complexity was associated with running fatigue (prunning state. We suggest that a practical outdoor running fatigue protocol that concurrently captures trunk accelerometry-based movement complexity warrants further prospective investigation as an in-situ screening tool for MTSS individuals. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Chronic exertional compartment syndrome with medial tibial stress syndrome in twins.

    Banerjee, Purnajyoti; McLean, Christopher

    2011-06-14

    Chronic exertional compartment syndrome and medial tibial stress syndrome are uncommon conditions that affect long-distance runners or players involved in team sports that require extensive running. We report 2 cases of bilateral chronic exertional compartment syndrome, with medial tibial stress syndrome in identical twins diagnosed with the use of a Kodiag monitor (B. Braun Medical, Sheffield, United Kingdom) fulfilling the modified diagnostic criteria for chronic exertional compartment syndrome as described by Pedowitz et al, which includes: (1) pre-exercise compartment pressure level >15 mm Hg; (2) 1 minute post-exercise pressure >30 mm Hg; and (3) 5 minutes post-exercise pressure >20 mm Hg in the presence of clinical features. Both patients were treated with bilateral anterior fasciotomies through minimal incision and deep posterior fasciotomies with tibial periosteal stripping performed through longer anteromedial incisions under direct vision followed by intensive physiotherapy resulting in complete symptomatic recovery. The etiology of chronic exertional compartment syndrome is not fully understood, but it is postulated abnormal increases in intramuscular pressure during exercise impair local perfusion, causing ischemic muscle pain. No familial predisposition has been reported to date. However, some authors have found that no significant difference exists in the relative perfusion, in patients, diagnosed with chronic exertional compartment syndrome. Magnetic resonance images of affected compartments have indicated that the pain is not due to ischemia, but rather from a disproportionate oxygen supply versus demand. We believe this is the first report of chronic exertional compartment syndrome with medial tibial stress syndrome in twins, raising the question of whether there is a genetic predisposition to the causation of these conditions. Copyright 2011, SLACK Incorporated.

  16. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments

    Franklyn, Melanie; Oakes, Barry

    2015-01-01

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging (MRI) can both be used for the diagnosis of MTSS, but the patient’s history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density (BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture (TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis

  17. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments.

    Franklyn, Melanie; Oakes, Barry

    2015-09-18

    Medial tibial stress syndrome (MTSS) is a debilitating overuse injury of the tibia sustained by individuals who perform recurrent impact exercise such as athletes and military recruits. Characterised by diffuse tibial anteromedial or posteromedial surface subcutaneous periostitis, in most cases it is also an injury involving underlying cortical bone microtrauma, although it is not clear if the soft tissue or cortical bone reaction occurs first. Nuclear bone scans and magnetic resonance imaging (MRI) can both be used for the diagnosis of MTSS, but the patient's history and clinical symptoms need to be considered in conjunction with the imaging findings for a correct interpretation of the results, as both imaging modalities have demonstrated positive findings in the absence of injury. However, MRI is rapidly becoming the preferred imaging modality for the diagnosis of bone stress injuries. It can also be used for the early diagnosis of MTSS, as the developing periosteal oedema can be identified. Retrospective studies have demonstrated that MTSS patients have lower bone mineral density (BMD) at the injury site than exercising controls, and preliminary data indicates the BMD is lower in MTSS subjects than tibial stress fracture (TSF) subjects. The values of a number of tibial geometric parameters such as cross-sectional area and section modulus are also lower in MTSS subjects than exercising controls, but not as low as the values in TSF subjects. Thus, the balance between BMD and cortical bone geometry may predict an individual's likelihood of developing MTSS. However, prospective longitudinal studies are needed to determine how these factors alter during the development of the injury and to find the detailed structural cause, which is still unknown. Finite element analysis has recently been used to examine the mechanisms involved in tibial stress injuries and offer a promising future tool to understand the mechanisms involved in MTSS. Contemporary accurate diagnosis

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

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

    2007-01-01

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

  19. Tension band plating of a nonunion anterior tibial stress fracture in an athlete.

    Merriman, Jarrad A; Villacis, Diego; Kephart, Curtis J; Rick Hatch, George F

    2013-07-01

    The authors present a rare technique of tension band plating of the anterior tibia in the setting of a nonunion stress fracture. Surgical management with an intramedullary nail is a viable and proven option for treating such injuries. However, in treating elite athletes, legitimate concerns exist regarding the surgical disruption of the extensor mechanism and the risk of anterior knee pain associated with intramedullary nail use. The described surgical technique demonstrates the use of tension band plating as an effective treatment of delayed union and nonunion anterior tibial stress fractures in athletes without the potential risks of intramedullary nail insertion. Copyright 2013, SLACK Incorporated.

  20. Postpartum osteoporosis associated with proximal tibial stress fracture

    Clemetson, I.A.; Anderson, S.E. [Department of Radiology, University Hospital of Bern, Inselspital, 3010, Bern (Switzerland); Popp, A.; Lippuner, K. [Department of Osteology, University Hospital of Bern, Inselspital, 3010, Bern (Switzerland); Ballmer, F. [Knee and Sports Medicine Unit, Lindenhofspital Bern, 3012, Bern (Switzerland)

    2004-02-01

    A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture. (orig.)

  1. Postpartum osteoporosis associated with proximal tibial stress fracture

    Clemetson, I.A.; Anderson, S.E.; Popp, A.; Lippuner, K.; Ballmer, F.

    2004-01-01

    A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture. (orig.)

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

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

    2015-07-01

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

  3. Proximal tibial stress fracture associated with mild osteoarthritis of the knee: case report.

    Curković, Marko; Kovac, Kristina; Curković, Bozidar; Babić-Naglić, Durda; Potocki, Kristina

    2011-03-01

    Stress fractures are considered as multifactorial overuse injuries occurring in 0.3%-0.8% of patients suffering from rheumatic diseases, with rheumatoid arthritis being the most common underlying condition. Stress fractures can be classified according to the condition of the bone affected as: 1) fatigue stress fractures occurring when normal bone is exposed to repeated abnormal stresses; and 2) insufficiency stress fractures that occur when normal stress is applied to bone weakened by an underlying condition. Stress fractures are rarely associated with severe forms of knee osteoarthritis, accompanied with malalignment and obesity. We present a patient with a proximal tibial stress fracture associated with mild knee osteoarthritis without associated malalignment or obesity. Stress fracture should be considered when a patient with osteoarthritis presents with sudden deterioration, severe localized tenderness to palpation and localized swelling or periosteal thickening at the pain site and elevated local temperature. The diagnosis of stress fractures in patients with rheumatic diseases may often be delayed because plain film radiographs may not reveal a stress fracture soon after the symptom onset; moreover, evidence of a fracture may never appear on plain radiographs. Triple phase nuclear bone scans and magnetic resonance imaging are more sensitive in the early clinical course than plain films for initial diagnosis.

  4. Peak stresses shift from femoral tunnel aperture to tibial tunnel aperture in lateral tibial tunnel ACL reconstructions: a 3D graft-bending angle measurement and finite-element analysis.

    Van Der Bracht, Hans; Tampere, Thomas; Beekman, Pieter; Schepens, Alexander; Devriendt, Wouter; Verdonk, Peter; Victor, Jan

    2018-02-01

    To investigate the effect of tibial tunnel orientation on graft-bending angle and stress distribution in the ACL graft. Eight cadaveric knees were scanned in extension, 45°, 90°, and full flexion. 3D reconstructions with anatomically placed anterior cruciate ligament (ACL) grafts were constructed with Mimics 14.12 ® . 3D graft-bending angles were measured for classic medial tibial tunnels (MTT) and lateral tibial tunnels (LTT) with different drill-guide angles (DGA) (45°, 55°, 65°, and 75°). A pivot shift was performed on 1 knee in a finite-element analysis. The peak stresses in the graft were calculated for eight different tibial tunnel orientations. In a classic anatomical ACL repair, the largest graft-bending angle and peak stresses are seen at the femoral tunnel aperture. The use of a different DGA at the tibial side does not change the graft-bending angle at the femoral side or magnitude of peak stresses significantly. When using LTT, the largest graft-bending angles and peak stresses are seen at the tibial tunnel aperture. In a classic anatomical ACL repair, peak stresses in the ACL graft are found at the femoral tunnel aperture. When an LTT is used, peak stresses are similar compared to classic ACL repairs, but the location of the peak stress will shift from the femoral tunnel aperture towards the tibial tunnel aperture. the risk of graft rupture is similar for both MTTs and LTTs, but the location of graft rupture changes from the femoral tunnel aperture towards the tibial tunnel aperture, respectively. I.

  5. Return to sports after stress fractures of the tibial diaphysis: a systematic review.

    Robertson, G A J; Wood, A M

    2015-06-01

    This review aims to provide information on the time taken to resume sport following tibial diaphyseal stress fractures (TDSFs). A systematic search of Medline, EMBASE, CINHAL, Cochrane, Web of Science, PEDro, Sports Discus, Scopus and Google Scholar was performed using the keywords 'tibial', 'tibia', 'stress', 'fractures', 'athletes', 'sports', 'non-operative', 'conservative', 'operative' and 'return to sport'. Twenty-seven studies were included: 16 reported specifically on anterior TDSFs and 5 on posterior TDSFs. The general principles were to primarily attempt non-operative management for all TDSFs and to consider operative intervention for anterior TDSFs that remained symptomatic after 3-6 months. Anterior TDSFs showed a prolonged return to sport. The best time to return to sport and the optimal management modalities for TDSFs remain undefined. Management of TDSFs should include a full assessment of training methods, equipment and diet to modify pre-disposing factors. Future prospective studies should aim to establish the optimal treatment modalities for TDSFs. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Plate Versus Intramedullary Nail Fixation of Anterior Tibial Stress Fractures: A Biomechanical Study.

    Markolf, Keith L; Cheung, Edward; Joshi, Nirav B; Boguszewski, Daniel V; Petrigliano, Frank A; McAllister, David R

    2016-06-01

    Anterior midtibial stress fractures are an important clinical problem for patients engaged in high-intensity military activities or athletic training activities. When nonoperative treatment has failed, intramedullary (IM) nail and plate fixation are 2 surgical options used to arrest the progression of a fatigue fracture and allow bone healing. A plate will be more effective than an IM nail in preventing the opening of a simulated anterior midtibial stress fracture from tibial bending. Controlled laboratory study. Fresh-frozen human tibias were loaded by applying a pure bending moment in the sagittal plane. Thin transverse saw cuts, 50% and 75% of the depth of the anterior tibial cortex, were created at the midtibia to simulate a fatigue fracture. An extensometer spanning the defect was used to measure the fracture opening displacement (FOD) before and after the application of IM nail and plate fixation constructs. IM nails were tested without locking screws, with a proximal screw only, and with proximal and distal screws. Plates were tested with unlocked bicortical screws (standard compression plate) and locked bicortical screws; both plate constructs were tested with the plate edge placed 1 mm from the anterior tibial crest (anterior location) and 5 mm posterior to the crest. For the 75% saw cut depth, the mean FOD values for all IM nail constructs were 13% to 17% less than those for the saw cut alone; the use of locking screws had no significant effect on the FOD. The mean FOD values for all plate constructs were significantly less than those for all IM nail constructs. The mean FOD values for all plates were 28% to 46% less than those for the saw cut alone. Anterior plate placement significantly decreased mean FOD values for both compression and locked plate constructs, but the mean percentage reductions for locked and unlocked plates were not significantly different from each other for either plate placement. The percentage FOD reductions for all plate

  7. Effectiveness of various isometric exercises at improving bone strength in cortical regions prone to distal tibial stress fractures.

    Florio, C S

    2018-06-01

    A computational model was used to compare the local bone strengthening effectiveness of various isometric exercises that may reduce the likelihood of distal tibial stress fractures. The developed model predicts local endosteal and periosteal cortical accretion and resorption based on relative local and global measures of the tibial stress state and its surface variation. Using a multisegment 3-dimensional leg model, tibia shape adaptations due to 33 combinations of hip, knee, and ankle joint angles and the direction of a single or sequential series of generated isometric resultant forces were predicted. The maximum stress at a common fracture-prone region in each optimized geometry was compared under likely stress fracture-inducing midstance jogging conditions. No direct correlations were found between stress reductions over an initially uniform circular hollow cylindrical geometry under these critical design conditions and the exercise-based sets of active muscles, joint angles, or individual muscle force and local stress magnitudes. Additionally, typically favorable increases in cross-sectional geometric measures did not guarantee stress decreases at these locations. Instead, tibial stress distributions under the exercise conditions best predicted strengthening ability. Exercises producing larger anterior distal stresses created optimized tibia shapes that better resisted the high midstance jogging bending stresses. Bent leg configurations generating anteriorly directed or inferiorly directed resultant forces created favorable adaptations. None of the studied loads produced by a straight leg was significantly advantageous. These predictions and the insight gained can provide preliminary guidance in the screening and development of targeted bone strengthening techniques for those susceptible to distal tibial stress fractures. Copyright © 2018 John Wiley & Sons, Ltd.

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

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

    2006-01-01

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

  9. Foot medial longitudinal-arch deformation during quiet standing and gait in subjects with medial tibial stress syndrome

    Bandholm, Thomas Quaade; Boysen, Lisbeth; Haugaard, Stine

    2008-01-01

    The objective of this study was to investigate (1) if subjects with medial tibial stress syndrome demonstrate increased navicular drop and medial longitudinal-arch deformation during quiet standing and gait compared with healthy subjects, and (2) the relationship between medial longitudinal-arch ...

  10. Spontaneous osteonecrosis of the knee associated with ipsilateral tibial plateau stress fracture: report of two patients and review of the literature

    Sokoloff, R.M.; Farooki, S.; Resnick, D.

    2001-01-01

    Two cases are presented of spontaneous osteonecrosis of the knee (SONK) associated with stress fractures of the tibial plateau. This association lends further credence to the postulate that SONK has a traumatic etiology. (orig.)

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

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

    2015-01-01

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

  12. Case report: multifocal subchondral stress fractures of the femoral heads and tibial condyles in a young military recruit.

    Yoon, Pil Whan; Yoo, Jeong Joon; Yoon, Kang Sup; Kim, Hee Joong

    2012-03-01

    Subchondral stress fractures of the femoral head may be either of the insufficiency-type with poor quality bone or the fatigue-type with normal quality bone but subject to high repetitive stresses. Unlike osteonecrosis, multiple site involvement rarely has been reported for subchondral stress fractures. We describe a case of multifocal subchondral stress fractures involving femoral heads and medial tibial condyles bilaterally within 2 weeks. A 27-year-old military recruit began having left knee pain after 2 weeks of basic training, without any injury. Subsequently, right knee, right hip, and left hip pain developed sequentially within 2 weeks. The diagnosis of multifocal subchondral stress fracture was confirmed by plain radiographs and MR images. Nonoperative treatment of the subchondral stress fractures of both medial tibial condyles and the left uncollapsed femoral head resulted in resolution of symptoms. The collapsed right femoral head was treated with a fibular strut allograft to restore congruity and healed without further collapse. There has been one case report in which an insufficiency-type subchondral stress fracture of the femoral head and medial femoral condyle occurred within a 2-year interval. Because the incidence of bilateral subchondral stress fractures of the femoral head is low and multifocal involvement has not been reported, multifocal subchondral stress fractures can be confused with multifocal osteonecrosis. Our case shows that subchondral stress fractures can occur in multiple sites almost simultaneously.

  13. Negative magnetic resonance imaging in three cases of anterior tibial cortex stress fractures

    Smith, Ralph; Moghal, M.; Newton, J.L.; Jones, N.; Teh, J.

    2017-01-01

    Anterior mid-tibial cortex stress fractures (ATCSF) are uncommon and notoriously challenging to treat. They are termed high risk due to their predilection to prolonged recovery, nonunion and complete fracture. Early diagnosis is essential to avoid progression and reduce fracture complications. Imaging plays a key role in confirming the diagnosis. Magnetic resonance imaging (MRI) is accepted as the gold standard modality due to its high accuracy and nonionizing properties. This report describes three cases of ATCSFs in recreational athletes who had positive radiographic findings with no significant MRI changes. Two athletes had multiple striations within their tibias. Despite the radiographic findings, their severity of symptoms were low with mild or no tenderness on examination. Clinicians should be mindful that the ATCSFs may not present with typical acute stress fracture symptoms. We recommend that plain radiographs should be used as the first line investigation when suspecting ATCSFs. Clinicians should be aware that despite MRI being considered the gold standard imaging modality, we report three cases where the MRI was unremarkable, whilst radiographs and computed tomography confirmed the diagnosis. We urge clinicians to continue to use radiographs as the first line imaging modality for ATCSFs and not to directly rely on MRI. Those who opt directly for MRI may be falsely reassured causing a delay in diagnosis. (orig.)

  14. Negative magnetic resonance imaging in three cases of anterior tibial cortex stress fractures

    Smith, Ralph; Moghal, M.; Newton, J.L.; Jones, N. [Oxford University Hospitals NHS Foundation Trust, Department of Sport and Exercise Medicine, Nuffield Orthopaedic Centre, Oxford (United Kingdom); Teh, J. [Oxford University Hospitals NHS Foundation Trust, Department of Radiology, Nuffield Orthopaedic Centre Oxford, Oxford (United Kingdom)

    2017-12-15

    Anterior mid-tibial cortex stress fractures (ATCSF) are uncommon and notoriously challenging to treat. They are termed high risk due to their predilection to prolonged recovery, nonunion and complete fracture. Early diagnosis is essential to avoid progression and reduce fracture complications. Imaging plays a key role in confirming the diagnosis. Magnetic resonance imaging (MRI) is accepted as the gold standard modality due to its high accuracy and nonionizing properties. This report describes three cases of ATCSFs in recreational athletes who had positive radiographic findings with no significant MRI changes. Two athletes had multiple striations within their tibias. Despite the radiographic findings, their severity of symptoms were low with mild or no tenderness on examination. Clinicians should be mindful that the ATCSFs may not present with typical acute stress fracture symptoms. We recommend that plain radiographs should be used as the first line investigation when suspecting ATCSFs. Clinicians should be aware that despite MRI being considered the gold standard imaging modality, we report three cases where the MRI was unremarkable, whilst radiographs and computed tomography confirmed the diagnosis. We urge clinicians to continue to use radiographs as the first line imaging modality for ATCSFs and not to directly rely on MRI. Those who opt directly for MRI may be falsely reassured causing a delay in diagnosis. (orig.)

  15. Rap system of stress stimulation can promote bone union after lower tibial bone fracture: a clinical research.

    Yao, Jian-fei; Shen, Jia-zuo; Li, Da-kun; Lin, Da-sheng; Li, Lin; Li, Qiang; Qi, Peng; Lian, Ke-jian; Ding, Zhen-qi

    2012-01-01

    Lower tibial bone fracture may easily cause bone delayed union or nonunion because of lacking of dynamic mechanical load. Research Group would design a new instrument as Rap System of Stress Stimulation (RSSS) to provide dynamic mechanical load which would promote lower tibial bone union postoperatively. This clinical research was conducted from January 2008 to December 2010, 92 patients(male 61/female 31, age 16-70 years, mean 36.3 years) who suffered lower tibial bone closed fracture were given intramedullary nail fixation and randomly averagely separated into experimental group and control group(according to the successively order when patients went for the admission procedure). Then researchers analysed the clinical healing time, full weight bearing time, VAS (Visual Analogue Scales) score and callus growth score of Lane-Sandhu in 3,6,12 months postoperatively. The delayed union and nonunion rates were compared at 6 and 12 months separately. All the 92 patients had been followed up (mean 14 months). Clinical bone healing time in experimental group was 88.78±8.80 days but control group was 107.91±9.03 days. Full weight bearing time in experimental group was 94.07±9.81 days but control group was 113.24±13.37 days respectively (Ptibial bone union, reduce bone delayed union or nonunion rate. It is an adjuvant therapy for promoting bone union after lower tibial bone fracture.

  16. "Shin splint" syndrome and tibial stress fracture in the same patient diagnosed by means of (99m)Tc-HMDP SPECT/CT.

    Vicente, Justo Serrano; Grande, Maria Luz Domínguez; Torre, Jose Rafael Infante; Madrid, Juan Ignacio Rayo; Barquero, Carmen Durán; Bernardo, Lucía García; Sánchez, Román Sánchez

    2013-04-01

    We show a patient who presented leg pain triggered by intense exercise. The most likely diagnosis was a possible tibial stress fracture or a "shin splint" syndrome (soleus enthesopathy). We performed a bone scintigraphy including SPECT/CT that revealed the presence of the two concomitant pathologies. SPECT/CT identified the hot spot superimposed with bone lesion in the tibial stress fracture and only remodeling activity without evidence of cortical lesions in the enthesopathy processes.

  17. Experimental and finite element analysis of tibial stress fractures using a rabbit model.

    Franklyn, Melanie; Field, Bruce

    2013-01-01

    To determine if rabbit models can be used to quantify the mechanical behaviour involved in tibial stress fracture (TSF) development. Fresh rabbit tibiae were loaded under compression using a specifically-designed test apparatus. Weights were incrementally added up to a load of 30 kg and the mechanical behaviour of the tibia was analysed using tests for buckling, bone strain and hysteresis. Structural mechanics equations were subsequently employed to verify that the results were within the range of values predicted by theory. A finite element (FE) model was developed using cross-sectional computer tomography (CT) images scanned from one of the rabbit bones, and a static load of 6 kg (1.5 times the rabbit's body weight) was applied to represent running. The model was validated using the experimental strain gauge data, then geometric and elemental convergence tests were performed in order to find the minimum number of cross-sectional scans and elements respectively required for convergence. The analysis was then performed using both the model and the experimental results to investigate the mechanical behaviour of the rabbit tibia under compressive load and to examine crack initiation. The experimental tests showed that under a compressive load of up to 12 kg, the rabbit tibia demonstrates linear behaviour with little hysteresis. Up to 30 kg, the bone does not fail by elastic buckling; however, there are low levels of tensile stress which predominately occur at and adjacent to the anterior border of the tibial midshaft: this suggests that fatigue failure occurs in these regions, since bone under cyclic loading initially fails in tension. The FE model predictions were consistent with both mechanics theory and the strain gauge results. The model was highly sensitive to small changes in the position of the applied load due to the high slenderness ratio of the rabbit's tibia. The modelling technique used in the current study could have applications in the development of

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

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

    2016-09-01

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

  19. Medial tibial stress syndrome can be diagnosed reliably using history and physical examination.

    Winters, M; Bakker, E W P; Moen, M H; Barten, C C; Teeuwen, R; Weir, A

    2017-02-08

    The majority of sporting injuries are clinically diagnosed using history and physical examination as the cornerstone. There are no studies supporting the reliability of making a clinical diagnosis of medial tibial stress syndrome (MTSS). Our aim was to assess if MTSS can be diagnosed reliably, using history and physical examination. We also investigated if clinicians were able to reliably identify concurrent lower leg injuries. A clinical reliability study was performed at multiple sports medicine sites in The Netherlands. Athletes with non-traumatic lower leg pain were assessed for having MTSS by two clinicians, who were blinded to each others' diagnoses. We calculated the prevalence, percentage of agreement, observed percentage of positive agreement (Ppos), observed percentage of negative agreement (Pneg) and Kappa-statistic with 95%CI. Forty-nine athletes participated in this study, of whom 46 completed both assessments. The prevalence of MTSS was 74%. The percentage of agreement was 96%, with Ppos and Pneg of 97% and 92%, respectively. The inter-rater reliability was almost perfect; k=0.89 (95% CI 0.74 to 1.00), phistory and physical examination, in clinical practice and research settings. We also found that concurrent lower leg injuries are common in athletes with MTSS. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Virtual stress testing of fracture stability in soldiers with severely comminuted tibial fractures.

    Petfield, Joseph L; Hayeck, Garry T; Kopperdahl, David L; Nesti, Leon J; Keaveny, Tony M; Hsu, Joseph R

    2017-04-01

    Virtual stress testing (VST) provides a non-invasive estimate of the strength of a healing bone through a biomechanical analysis of a patient's computed tomography (CT) scan. We asked whether VST could improve management of patients who had a tibia fracture treated with external fixation. In a retrospective case-control study of 65 soldier-patients who had tibia fractures treated with an external fixator, we performed VST utilizing CT scans acquired prior to fixator removal. The strength of the healing bone and the amount of tissue damage after application of an overload were computed for various virtual loading cases. Logistic regression identified computed outcomes with the strongest association to clinical events related to nonunion within 2 months after fixator removal. Clinical events (n = 9) were associated with a low tibial strength for compression loading (p fracture patients who can safely resume weight bearing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:805-811, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

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

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

    2007-02-01

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

  2. Intra-epiphyseal stress injury of the proximal tibial epiphysis: Preliminary experience of magnetic resonance imaging findings

    Tony, G., E-mail: drgtony@gmail.com [Stafford General Hospital, Weston Road, Stafford, Staffordshire ST16 3SA (United Kingdom); Charran, A., E-mail: amandacharran@yahoo.com [Hillingdon Hospital, Pield Heath Rd, Uxbridge, Middlesex UB8 3NN (United Kingdom); Tins, B., E-mail: bernhard.tins@rjah.nhs.uk [Department of Diagnostic Imaging, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Lalam, R., E-mail: radhesh.lalam@rjah.nhs.uk [Department of Diagnostic Imaging, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Tyrrell, P.N.M., E-mail: prudencia.tyrrell@rjah.nhs.uk [Department of Diagnostic Imaging, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Singh, J., E-mail: jaspreet.singh@rjah.nhs.uk [Department of Diagnostic Imaging, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Cool, P., E-mail: paul.cool@rjah.nhs.uk [Orthopaedic Oncology, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Kiely, N., E-mail: nigel.kiely@rjah.nhs.uk [Paediatric Orthopaedics, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom); Cassar-Pullicino, V.N., E-mail: Victor.Pullicino@rjah.nhs.uk [Department of Diagnostic Imaging, Robert Jones and Agnes Hunt, Orthopaedic Hospital, Oswestry, Shropshire SY10 7 AG (United Kingdom)

    2014-11-15

    Highlights: • Purely intra-epiphyseal stress injuries of the proximal tibial epiphysis are described for the first time. • The variation in the MRI findings of these injuries depending on the stage of maturation is demonstrated. • We postulate a patho-mechanism to explain the variations in site and appearance of stress injuries in this region. - Abstract: Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families.

  3. Intra-epiphyseal stress injury of the proximal tibial epiphysis: Preliminary experience of magnetic resonance imaging findings

    Tony, G.; Charran, A.; Tins, B.; Lalam, R.; Tyrrell, P.N.M.; Singh, J.; Cool, P.; Kiely, N.; Cassar-Pullicino, V.N.

    2014-01-01

    Highlights: • Purely intra-epiphyseal stress injuries of the proximal tibial epiphysis are described for the first time. • The variation in the MRI findings of these injuries depending on the stage of maturation is demonstrated. • We postulate a patho-mechanism to explain the variations in site and appearance of stress injuries in this region. - Abstract: Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families

  4. Accelerated stress testing of terrestrial solar cells

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  5. Ankle and toe muscle strength characteristics in runners with a history of medial tibial stress syndrome.

    Saeki, Junya; Nakamura, Masatoshi; Nakao, Sayaka; Fujita, Kosuke; Yanase, Ko; Morishita, Katsuyuki; Ichihashi, Noriaki

    2017-01-01

    A high proportion of flexor digitorum longus attachment is found at the posteromedial border of the tibia, which is the most common location of medial tibial stress syndrome (MTSS). Therefore, plantar flexion strength of the lesser toes could be related to MTSS; however, the relationship between MTSS and muscle strength of the hallux and lesser toes is not yet evaluated due to the lack of quantitative methods. This study investigated the muscle strength characteristics in runners with a history of MTSS by using a newly developed device to measure the muscle strength of the hallux, lesser toes, and ankle. This study comprised 27 collegiate male runner participants (20.0 ± 1.6 years, 172.1 ± 5.1 cm, 57.5 ± 4.0 kg). Maximal voluntary isometric contraction (MVIC) torque of the plantar flexion, dorsiflexion, inversion, and eversion of the ankle were measured by using an electric dynamometer. MVIC torque of the 1st metatarsophalangeal joint (MTPJ) and 2nd-5th MTPJ were measured by using a custom-made torque-measuring device. MVIC torques were compared between runners with and without a history of MTSS. MVIC torque of the 1st MTPJ plantar flexion was significantly higher in runners with a history of MTSS than in those without it. In contrast, there were no significant differences in the MVIC torque values of the 2nd-5th MTPJ plantar flexion and each MVIC torque of the ankle between runners with and without a history of MTSS. A history of MTSS increased the isometric FHL strength.

  6. Muscle stiffness of posterior lower leg in runners with a history of medial tibial stress syndrome.

    Saeki, J; Nakamura, M; Nakao, S; Fujita, K; Yanase, K; Ichihashi, N

    2018-01-01

    Previous history of medial tibial stress syndrome (MTSS) is a risk factor for MTSS relapse, which suggests that there might be some physical factors that are related to MTSS development in runners with a history of MTSS. The relationship between MTSS and muscle stiffness can be assessed in a cross-sectional study that measures muscle stiffness in subjects with a history of MTSS, who do not have pain at the time of measurement, and in those without a history of MTSS. The purpose of this study was to compare the shear elastic modulus, which is an index of muscle stiffness, of all posterior lower leg muscles of subjects with a history of MTSS and those with no history and investigate which muscles could be related to MTSS. Twenty-four male collegiate runners (age, 20.0±1.7 years; height, 172.7±4.8 cm; weight, 57.3±3.7 kg) participated in this study; 14 had a history of MTSS, and 10 did not. The shear elastic moduli of the lateral gastrocnemius, medial gastrocnemius, soleus, peroneus longus, peroneus brevis, flexor hallucis longus, flexor digitorum longus, and tibialis posterior were measured using shear wave elastography. The shear elastic moduli of the flexor digitorum longus and tibialis posterior were significantly higher in subjects with a history of MTSS than in those with no history. However, there was no significant difference in the shear elastic moduli of other muscles. The results of this study suggest that flexor digitorum longus and tibialis posterior stiffness could be related to MTSS. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. [Effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation].

    Ge, Qihang; Wan, Chunyou; Liu, Yabei; Ji, Xu; Ma, Jihai; Cao, Haikun; Yong, Wei; Liu, Zhao; Zhang, Ningning

    2017-08-01

    To investigate the effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation. The data of 45 cases with tibial and fibular open fractures treated by Taylor space stent fixation who meet the selection criteria between January 2015 and June 2016 were retrospectively analysed. The patients were divided into trial group (23 cases) and control group (22 cases) according to whether the axial stress stimulation was performed after operation. There was no significant difference in gender, age, affected side, cause of injury, type of fracture, and interval time from injury to operation between 2 groups ( P >0.05). The axial stress stimulation was performed in trial group after operation. The axial load sharing ratio was tested, and when the value was less than 10%, the external fixator was removed. The fracture healing time, full weight-bearing time, and external fixator removal time were recorded and compared. After 6 months of external fixator removal, the function of the limb was assessed by Johner-Wruhs criteria for evaluation of final effectiveness of treatment of tibial shaft fractures. There were 2 and 3 cases of needle foreign body reaction in trial group and control group, respectively, and healed after symptomatic anti allergic treatment. All the patients were followed up 8-12 months with an average of 10 months. All the fractures reached clinical healing, no complication such as delayed union, nonunion, or osteomyelitis occurred. The fracture healing time, full weight-bearing time, and external fixator removal time in trial group were significantly shorter than those in control group ( P good in 6 cases, fair in 3 cases, and poor in 1 case in trial group, with an excellent and good rate of 82.6%; and was excellent in 5 cases, good in 10 cases, fair in 4 cases, and poor in 3 cases in control group, with an excellent and good rate of 68.2%, showing significant difference between 2 groups ( Z =-2.146, P =0

  8. Tibial stress reaction presenting as bilateral shin pain in a man taking denosumab for giant cell tumor of the bone.

    Lim, Sian Yik; Rastalsky, Naina; Choy, Edwin; Bolster, Marcy B

    2015-12-01

    Prolonged bisphosphonate use has been associated with increased risk of atypical femoral fractures. Very few cases of atypical femoral fractures have been reported with denosumab. We report a case of bilateral tibial stress reactions in a 60-year-old man with no history of osteoporosis who was on prolonged high-dose denosumab for the treatment of giant cell tumor of bone. He presented with a 3-month history of pain in his bilateral shins worsening with activity and improving with rest. Although initial radiographs were unremarkable, he was found to have changes consistent with a stress reaction on magnetic resonance imaging of the distal tibia. To our knowledge, bilateral tibial stress reactions have not been previously reported with anti-resorptive therapies (neither bisphosphonates nor denosumab). Our case is intriguing in terms of the development of stress reactions as a precursor to stress fractures which may also relate to atypical fractures. Our case suggests a possible association between denosumab use and stress reactions. Of note the indication for denosumab in our case was for the treatment of giant cell tumor of bone where the Food and Drug Administration (FDA) approved dose is substantially higher than the FDA approved dose for osteoporosis treatment. Although rare, clinicians should consider the possibility of stress fractures in patients on anti-resorptive medications such as denosumab, especially when a patient presents with new onset thigh pain, hip pain or pain over an area affecting the long bones. Evaluation by imaging of affected areas should be pursued to enable early detection and intervention, as well as prevention of morbidity and associated ongoing risk to the patient. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Post-Cam Design and Contact Stress on Tibial Posts in Posterior-Stabilized Total Knee Prostheses: Comparison Between a Rounded and a Squared Design.

    Watanabe, Toshifumi; Koga, Hideyuki; Horie, Masafumi; Katagiri, Hiroki; Sekiya, Ichiro; Muneta, Takeshi

    2017-12-01

    The post-cam mechanism in posterior stabilized (PS) prostheses plays an important role in total knee arthroplasty (TKA). The purpose of this study is to clarify the difference of the contact stress on the tibial post between a rounded post-cam design and a squared design during deep knee flexion and at hyperextension using the three-dimensional (3D) finite element models. We created 2 types of 3D, finite element models of PS prostheses (types A and B), whose surfaces were identical except for the post-cam geometries: type A has a rounded post-cam design, while type B has a squared design. Both types have a similar curved-shape intercondylar notch of the femoral component. Stress distributions, peak contact stresses, and contact areas on the tibial posts at 90°, 120°, and 150° flexion with/without 10° tibial internal rotation and at 10° hyperextension were compared between the 2 models. Type B demonstrated more concentrated stress distribution compared to type A. The peak contact stresses were similar in both groups during neutral flexion; however, the stresses were much higher in type B during flexion with 10° rotation and at hyperextension. The higher peak contact stresses corresponded to the smaller contact areas in the tibial post. A rounded post-cam design demonstrated less stress concentration during flexion with rotation and at hyperextension compared with a squared design. The results would be useful for development of implant designs and prediction of the contact stress on the tibial post in PS total knee arthroplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The Stress Acceleration Hypothesis of Nightmares

    Tore Nielsen

    2017-06-01

    Full Text Available Adverse childhood experiences can deleteriously affect future physical and mental health, increasing risk for many illnesses, including psychiatric problems, sleep disorders, and, according to the present hypothesis, idiopathic nightmares. Much like post-traumatic nightmares, which are triggered by trauma and lead to recurrent emotional dreaming about the trauma, idiopathic nightmares are hypothesized to originate in early adverse experiences that lead in later life to the expression of early memories and emotions in dream content. Accordingly, the objectives of this paper are to (1 review existing literature on sleep, dreaming and nightmares in relation to early adverse experiences, drawing upon both empirical studies of dreaming and nightmares and books and chapters by recognized nightmare experts and (2 propose a new approach to explaining nightmares that is based upon the Stress Acceleration Hypothesis of mental illness. The latter stipulates that susceptibility to mental illness is increased by adversity occurring during a developmentally sensitive window for emotional maturation—the infantile amnesia period—that ends around age 3½. Early adversity accelerates the neural and behavioral maturation of emotional systems governing the expression, learning, and extinction of fear memories and may afford short-term adaptive value. But it also engenders long-term dysfunctional consequences including an increased risk for nightmares. Two mechanisms are proposed: (1 disruption of infantile amnesia allows normally forgotten early childhood memories to influence later emotions, cognitions and behavior, including the common expression of threats in nightmares; (2 alterations of normal emotion regulation processes of both waking and sleep lead to increased fear sensitivity and less effective fear extinction. These changes influence an affect network previously hypothesized to regulate fear extinction during REM sleep, disruption of which leads to

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

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

    2015-01-01

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

  12. Stresses in the foil of an electron accelerator extraction channel

    Abroyan, M.A.; Makarenko, T.I.; Tokmakov, I.L.

    1983-01-01

    Stresses in the foil of an electron accelerator extraction channel are assessed with account of contributions of thermal expansion and stress concentrations during switchings. Optimization of extraction grid parameters of the electron accelerator extraction channel and choice of foil material for high current electron beam is conducted. It is suggested that an extraction grid with circular cells and Al-Mg foil should be used. A simple formula applicable for design calculations is proposed for evaluation of stress concentration coefficient during phase switchings

  13. The relationship between lower extremity alignment and Medial Tibial Stress Syndrome among non-professional athletes

    Raissi Golam

    2009-06-01

    Full Text Available Abstract Objective To determine the relationship between lower extremity alignment and MTSS amongst non-professional athletes Design In a prospective Study, sixty six subjects were evaluated. Bilateral navicular drop test, Q angle, Achilles angle, tibial angle, intermalleolar and intercondylar distance were measured. In addition, runner's height, body mass, history of previous running injury, running experience was recorded. Runners were followed for 17 weeks to determine occurrence of MTSS. Results The overall injury rate for MTSS was 19.7%. The MTSS injury rate in girls (22% was not significantly different from the rate in boys (14.3%. Most MTSS injuries were induced after 60 hours of exercise, which did not differ between boys and girls. There was a significant difference in right and left navicular drop (ND in athletes with MTSS. MTSS had no significant correlation with other variables including Quadriceps, Tibia and Achilles angles, intercondylar and intermaleolar lengths and lower extremity lengths. Limitation All measurements performed in this study were uniplanar and static. The small sample size deemed our main limitation. The accurate assessment of participants with previous history of anterior leg pain for MTSS was another limitation. Conclusion Although a significant relationship between navicular drop and MTSS was found in this study; there was not any significant relationship between lower extremity alignment and MTSS in our sample study.

  14. Massage treatment and medial tibial stress syndrome; A commentary to provoke thought about the way massage therapy is used in the treatment of MTSS.

    Fogarty, Sarah

    2015-07-01

    As students and practitioners we are taught about the treatment and causative factors of medial shin pain, in particular' shin splints' or the more recent term; medial tibial stress syndrome (MTSS). During the years there have been many theories, conjecture and misunderstandings about the mechanisms of 'shin splints/medial tibial stress syndrome' however the ramifications of these mechanisms on how massage treatment is delivered have not being discussed. The evidence for the treatment of MTSS is largely clinical with little evidence of any treatment being proven to be effective in treating MTSS. The aim of this article is to present a summary of the mechanisms of MTSS and a commentary to provoke thought about the way massage therapy is used in the treatment of MTSS based on these mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Risk factors associated with medial tibial stress syndrome in runners: a systematic review and meta-analysis

    Newman P

    2013-11-01

    Full Text Available Phil Newman, Jeremy Witchalls, Gordon Waddington, Roger Adams Faculty of Health, Physiotherapy, University of Canberra, Bruce, ACT, Australia Background: Medial tibial stress syndrome (MTSS affects 5%–35% of runners. Research over the last 40 years investigating a range of interventions has not established any clearly effective management for MTSS that is better than prolonged rest. At the present time, understanding of the risk factors and potential causative factors for MTSS is inconclusive. The purpose of this review is to evaluate studies that have investigated various risk factors and their association with the development of MTSS in runners. Methods: Medical research databases were searched for relevant literature, using the terms “MTSS AND prevention OR risk OR prediction OR incidence”. Results: A systematic review of the literature identified ten papers suitable for inclusion in a meta-analysis. Measures with sufficient data for meta-analysis included dichotomous and continuous variables of body mass index (BMI, ankle dorsiflexion range of motion, navicular drop, orthotic use, foot type, previous history of MTSS, female gender, hip range of motion, and years of running experience. The following factors were found to have a statistically significant association with MTSS: increased hip external rotation in males (standard mean difference [SMD] 0.67, 95% confidence interval [CI] 0.29–1.04, P10 mm (RR 1.99, 95% CI 1.00–3.96, P=0.05. Conclusion: Female gender, previous history of MTSS, fewer years of running experience, orthotic use, increased body mass index, increased navicular drop, and increased external rotation hip range of motion in males are all significantly associated with an increased risk of developing MTSS. Future studies should analyze males and females separately because risk factors vary by gender. A continuum model of the development of MTSS that links the identified risk factors and known processes is proposed

  16. Fratura periprotética da tíbia combinada com fratura de fadiga da haste tibial de artroplastia total do joelho Tibial periprosthetic fracture combined with tibial stem stress fracture from total knee arthroplasty

    Fernando Fonseca

    2011-01-01

    Full Text Available As complicações das artroplastias totais do joelho relacionadas com o próprio material são muito raras, exceto o desgaste do polietileno. Neste artigo os autores reportam o caso de uma paciente do sexo feminino de 58 anos referenciada ao pronto-socorro do nosso hospital por uma fratura periprotética tibial (tipo I da classificação da Mayo Clinic. Uma observação mais cuidadosa mostrou a presença concomitante da referida fratura da tíbia associada à fratura de fadiga da haste tibial. A prótese com a haste foi remetida a um laboratório de biomecânica independente onde foi avaliada e efetuada uma reconstrução com uso de sistema de elementos finitos em CAD de modo a verificar a existência de algum defeito de fabricação e as eventuais causas para o sucedido. Depois de avaliadas diversas hipóteses, concluiu-se que a fratura do material foi provocada por uma sobrecarga na zona de transição prato/haste secundária à falência óssea prévia (fratura. Da avaliação do caso ressalta-se novamente a necessidade de efetuar uma avaliação adequada da mineralização óssea e, em caso de dúvida, utilizar uma haste longa.Total knee arthroplasty complications related to the prosthetic material are very rare, except for polyethylene wear. We report the case of a 58-year-old woman who came to the emergency service of our hospital with a periprosthetic tibial fracture (Mayo Clinic type I. Careful examination showed that this fracture was concomitantly associated with a tibial stem fatigue fracture. The prosthesis and the stem were sent to an independent biomechanics laboratory for evaluation. A finite-element CAD system was used to make a reconstruction, so as to ascertain whether there had been any manufacturing defect and what the causes of the event might have been. After evaluation of several hypotheses, it was concluded that the fracture in the prosthetic material had been caused by overloading at the plate/stem transition zone

  17. Comparison of plantar flexor musculotendinous stiffness, geometry, and architecture in male runners with and without a history of tibial stress fracture.

    Pamukoff, Derek N; Blackburn, J Troy

    2015-02-01

    Greater lower extremity joint stiffness may be related to the development of tibial stress fractures in runners. Musculotendinous stiffness is the largest contributor to joint stiffness, but it is unclear what factors contribute to musculotendinous stiffness. The purpose of this study was to compare plantar flexor musculotendinous stiffness, architecture, geometry, and Achilles tendon stiffness between male runners with and without a history of tibial stress fracture. Nineteen healthy runners (age = 21 ± 2.7 years; mass = 68.2 ± 9.3 kg; height = 177.3 ± 6.0 cm) and 19 runners with a history of tibial stress fracture (age = 21 ± 2.9 years; mass = 65.3 ± 6.0 kg; height = 177.2 ± 5.2 cm) were recruited from community running groups and the university's varsity and club cross-country teams. Plantar flexor musculotendinous stiffness was estimated from the damped frequency of oscillatory motion about the ankle follow perturbation. Ultrasound imaging was used to measure architecture and geometry of the medial gastrocnemius. Dependent variables were compared between groups via one-way ANOVAs. Previously injured runners had greater plantar flexor musculotendinous stiffness (P < .001), greater Achilles tendon stiffness (P = .004), and lesser Achilles tendon elongation (P = .003) during maximal isometric contraction compared with healthy runners. No differences were found in muscle thickness, pennation angle, or fascicle length.

  18. Bilateral Tibial Stress Fractures in a Young Man Associated with Idiopathic Osteoporosis - Case Report

    Selahattin Özyürek

    2010-12-01

    Full Text Available Stress fractures are defined as a partial or complete fracture of bone due to an inability to endure a non-violent stress. Two factors have been proposed to explain the aetiology of stress fractures: muscle fatigue, and direct muscle action. We want to point to third factor with our case report: Osteoporosis. (From the World of Osteoporosis 2010;16:58-60

  19. A cross-sectional study of the effects of load carriage on running characteristics and tibial mechanical stress: implications for stress-fracture injuries in women.

    Xu, Chun; Silder, Amy; Zhang, Ju; Reifman, Jaques; Unnikrishnan, Ginu

    2017-03-23

    Load carriage is associated with musculoskeletal injuries, such as stress fractures, during military basic combat training. By investigating the influence of load carriage during exercises on the kinematics and kinetics of the body and on the biomechanical responses of bones, such as the tibia, we can quantify the role of load carriage on bone health. We conducted a cross-sectional study using an integrated musculoskeletal-finite-element model to analyze how the amount of load carriage in women affected the kinematics and kinetics of the body, as well as the tibial mechanical stress during running. We also compared the biomechanics of walking (studied previously) and running under various load-carriage conditions. We observed substantial changes in both hip kinematics and kinetics during running when subjects carried a load. Relative to those observed during running without load, the joint reaction forces at the hip increased by an average of 49.1% body weight when subjects carried a load that was 30% of their body weight (ankle, 4.8%; knee, 20.6%). These results indicate that the hip extensor muscles in women are the main power generators when running with load carriage. When comparing running with walking, finite element analysis revealed that the peak tibial stress during running (tension, 90.6 MPa; compression, 136.2 MPa) was more than three times as great as that during walking (tension, 24.1 MPa; compression, 40.3 MPa), whereas the cumulative stress within one stride did not differ substantially between running (15.2 MPa · s) and walking (13.6 MPa · s). Our findings highlight the critical role of hip extensor muscles and their potential injury in women when running with load carriage. More importantly, our results underscore the need to incorporate the cumulative effect of mechanical stress when evaluating injury risk under various exercise conditions. The results from our study help to elucidate the mechanisms of stress fracture in women.

  20. An integrative modeling approach for the efficient estimation of cross sectional tibial stresses during locomotion.

    Derrick, Timothy R; Edwards, W Brent; Fellin, Rebecca E; Seay, Joseph F

    2016-02-08

    The purpose of this research was to utilize a series of models to estimate the stress in a cross section of the tibia, located 62% from the proximal end, during walking. Twenty-eight male, active duty soldiers walked on an instrumented treadmill while external force data and kinematics were recorded. A rigid body model was used to estimate joint moments and reaction forces. A musculoskeletal model was used to gather muscle length, muscle velocity, moment arm and orientation information. Optimization procedures were used to estimate muscle forces and finally internal bone forces and moments were applied to an inhomogeneous, subject specific bone model obtained from CT scans to estimate stress in the bone cross section. Validity was assessed by comparison to stresses calculated from strain gage data in the literature and sensitivity was investigated using two simplified versions of the bone model-a homogeneous model and an ellipse approximation. Peak compressive stress occurred on the posterior aspect of the cross section (-47.5 ± 14.9 MPa). Peak tensile stress occurred on the anterior aspect (27.0 ± 11.7 MPa) while the location of peak shear was variable between subjects (7.2 ± 2.4 MPa). Peak compressive, tensile and shear stresses were within 0.52 MPa, 0.36 MPa and 3.02 MPa respectively of those calculated from the converted strain gage data. Peak values from a inhomogeneous model of the bone correlated well with homogeneous model (normal: 0.99; shear: 0.94) as did the normal ellipse model (r=0.89-0.96). However, the relationship between shear stress in the inhomogeneous model and ellipse model was less accurate (r=0.64). The procedures detailed in this paper provide a non-invasive and relatively quick method of estimating cross sectional stress that holds promise for assessing injury and osteogenic stimulus in bone during normal physical activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture: a comparative finite element study.

    Huang, Xiaowei; Zhi, Zhongzheng; Yu, Baoqing; Chen, Fancheng

    2015-11-25

    The purpose of this study is to compare the stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture. A three-dimensional (3D) finite element model of the medial tibial plateau fracture (Schatzker type IV fracture) was created. An axial force of 2500 N with a distribution of 60% to the medial compartment was applied to simulate the axial compressive load on an adult knee during single-limb stance. The equivalent von Mises stress, displacement of the model relative to the distal tibia, and displacement of the implants were used as the output measures. The mean stress value of the plate-screw fixation system was 18.78 MPa, which was significantly (P stress value of the triangular fragment in the plate-screw fixation system model was 42.04 MPa, which was higher than that in the screw fixation model (24.18 MPa). But the mean stress of the triangular fractured fragment in the screw fixation model was significantly higher in terms of equivalent von Mises stress (EVMS), x-axis, and z-axis (P < 0.001). This study demonstrated that the load transmission mechanism between plate-screw fixation system and screw fixation system was different and the stability provided by the plate-screw fixation system was superior to the screw fixation system.

  2. Treatment of Medial Tibial Stress Syndrome With Radial Soundwave Therapy in Elite Athletes: Current Evidence, Report on Two Cases, and Proposed Treatment Regimen.

    Saxena, Amol; Fullem, Brian; Gerdesmeyer, Ludger

    Two case reports of high-level athletes with medial tibial stress syndrome (MTSS), 1 an Olympian with an actual stress fracture, are presented. Successful treatment included radial soundwave therapy, pneumatic leg braces, relative rest using an antigravity treadmill, and temporary foot orthoses. Radial soundwave therapy has a high level of evidence for treatment of MTSS. We also present recent evidence of the value of vitamin D assessment. Both patients had a successful outcome with minimal downtime. Finally, a suggested treatment regimen for MTSS is presented. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  3. Finite Element Analysis of Absorbable Sheath to Prevent Stress Shielding of Tibial Interlocking Intramedullary Nail

    Dong, Yansheng; Wang, Yongqing; Dong, Limin; Jia, Peng; Lu, Fengcheng

    2017-07-01

    The nail with absorbable sheath (AS nail) is designed to reduce the stress shielding effect of internal fixation with interlocking intramedullary nail. In order to verify its feasibility, two types of the finite element models of internal fixation of tibia with the AS nail and the common metal nail (CM nail) are established using the Softwares of Mimics, Geomagic, SolidWorks and ANSYS according to the CT scanning data of tibia. The result of the finite element analysis shows that the AS nail has great advantages compared with the CM nail in reducing the stress shielding effect in different periods of fracture healing. The conclusion is that the AS nail can realize the static fixation to the dynamic fixation from the early to the later automatically to shorten the time of fracture healing, which also provides a new technique to the interlocking intramedullary nail.

  4. The soleus syndrome. A cause of medial tibial stress (shin splints).

    Michael, R H; Holder, L E

    1985-01-01

    Radionuclide bone scans have demonstrated linear uptake along the posterior medial border of the tibia in patients with shin splints. This area was investigated by anatomical dissection (14 human cadavers), electromyographic (EMG) and muscle stimulation studies (10 patients), and open biopsy (1 patient). Histologically, the increased metabolic activity manifested on the radionuclide scan is due to a periostitis with new bone formation. The soleus muscle and its investing fascia are anatomically and biomechanically implicated in the production of these stress changes, particularly when the heel is in the pronated position. The soleus muscle and fascia form a tough "soleus bridge" over the deep compartment which is thought to be important in patients requiring surgical decompression.

  5. Reducing Variability in Stress Drop with Root-Mean Acceleration

    Crempien, J.; Archuleta, R. J.

    2012-12-01

    Stress drop is a fundamental property of the earthquake source. For a given tectonic region stress drop is assumed to be constant allowing for the scaling of earthquake spectra. However, the variability of the stress drop, either for worldwide catalogs or regional catalogs, is quite large. The variability around the median value is on the order of 1.5 in log10 units. One question that continues to pervade the analysis of stress drop is whether this variability is an inherent characteristic of the Earth or is an artifact of the determination of stress drop via the use of the spectral analysis. It is simple to see that the stress drop determined by seismic moment times corner frequency cubed that errors in the corner frequency will strongly influence the variability in the stress drop. To avoid this strong dependence on corner frequency cubed, we have examined the determination of stress drop based on the approach proposed by Hanks (1979), namely using the root-mean-square acceleration. The stress drop determined using rms acceleration may be advantageous because the stress drop is only affected by the square root of the corner frequency. To test this approach we have determined stress drops for the 2000 Tottori earthquake and its aftershocks. We use both the classic method of fitting to a spectrum as well as using rms acceleration. For a preliminary analysis of eight aftershocks and the mainshock we find that the variability in stress drop is reduced by about a factor of two. This approach needs more careful analysis of more events, which will be shown at the meeting.

  6. Using Uncertainty Analysis to Guide the Development of Accelerated Stress Tests (Presentation)

    Kempe, M.

    2014-03-01

    Extrapolation of accelerated testing to the long-term results expected in the field has uncertainty associated with the acceleration factors and the range of possible stresses in the field. When multiple stresses (such as temperature and humidity) can be used to increase the acceleration, the uncertainty may be reduced according to which stress factors are used to accelerate the degradation.

  7. An acceleration test for stress corrosion cracking using humped specimen

    Kamaya, Masayuki; Fukumura, Takuya; Totsuka, Nobuo

    2003-01-01

    By using the humped specimen, which is processed by the humped die, in the slow strain rate technique (SSRT) test, fracture facet due to stress corrosion cracking (SCC) can be observed in relatively short duration. Although the cold work and concentrated stress and strain caused by the characteristic shape of the specimen accelerate the SCC, to date these acceleration effects have not been examined quantitatively. In the present study, the acceleration effects of the humped specimen were examined through experiments and finite element analyses (FEA). The experiments investigated the SCC of alloy 600 in the primary water environment of a pressurized water reactor. SSRT tests were conducted using two kinds of humped specimen: one was annealed after hump processing in order to eliminate the cold work, and the other was hump processed after the annealing treatment. The work ratio caused by the hump processing and stress/strain conditions during SSRT test were evaluated by FEA. It was found that maximum work ratio of 30% is introduced by the hump processing and that the distribution of the work ratio is not uniform. Furthermore, the work ratio is influenced by the friction between the specimen and dies as well as by the shape of dies. It was revealed that not only the cold work but also the concentrated stress and strain during SSRT test accelerate the crack initiation and growth of the SCC. (author)

  8. Dysregulated physiological stress systems and accelerated cellular aging

    Révész, D.; Verhoeven, J.; Milaneschi, Y.; de Geus, E.J.C.; Wolkowitz, O.M.; Penninx, B.W.J.H.

    2014-01-01

    Exposure to chronic stressors is associated with accelerated biological aging as indicated by reduced leukocyte telomere length (LTL). This impact could be because of chronic overactivation of the body's physiological stress systems. This study examined the associations between LTL and the immune

  9. Method for accelerated aging under combined environmental stress conditions

    Gillen, K.T.

    1979-01-01

    An accelerated aging method which can be used to simulate aging in combined stress environment situations is described. It is shown how the assumptions of the method can be tested experimentally. Aging data for a chloroprene cable jacketing material in single and combined radiation and temperature environments are analyzed and it is shown that these data offer evidence for the validity of the method

  10. Temperature rise and stress induced by microcracks in accelerating structures

    W. Zhu

    2010-12-01

    Full Text Available The temperature rise and induced stress due to Ohmic heating in the vicinity of microcracks on the walls of high-gradient accelerating structures are considered. The temperature rise and induced stress depend on the orientation of the crack with respect to the rf magnetic field, the shape of the crack, and the power and duration of the rf pulse. Under certain conditions the presence of cracks can double the temperature rise over that of a smooth surface. Stress at the bottom of the cracks can be several times larger than that of the case when there are no cracks. We study these effects both analytically and by computer simulation. It is shown that the stress in cracks is maximal when the crack depth is on the order of the thermal penetration depth.

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

    Wing-Kai Lam

    2018-05-01

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

  12. Feasibility, safety and tolerability of accelerated dobutamine stress echocardiography

    Pavaci Herribert

    2007-11-01

    Full Text Available Abstract A continuous infusion of a single high dose of dobutamine has been, recently, suggested as a simple and effective protocol of stress echocardiography. The present study assesses the feasibility, safety, and tolerability of an accelerated dobutamine stress protocol performed in patients with suspected or known coronary artery disease. Two hundred sixty five consecutive patients underwent accelerated dobutamine stress echocardiography: the dobutamine was administered at a constant dose of 50 μg/kg/min for up to 10 minutes. The mean weight-adjusted cumulative dose of dobutamine used was 330 ± 105.24 μg/kg. Total duration of dobutamine infusion was 6.6 ± 2.1 min. Heart rate rose from 69.9 ± 12.1 to 123.1 ± 22.1 beats/min at peak with a concomitant change in systolic blood pressure (127.6 ± 18.1 vs. 167.6 ± 45.0 mmHg. Dobutamine administration produced a rapid increase in heart rate (9.4 ± 5.9 beats/min2. The side effects were similar to those described with the standard protocol; the most common were frequent premature ventricular complexes (21.5%, frequent premature atrial complexes (1.5% and non sustained ventricular tachycardia (1.5%; among non cardiac symptoms the most frequent were nausea (3.4%, headache (1.1% and symptomatic hypotension (1.1%. No major side effects were observed during the test. Our data demonstrate that a continous infusion of a single high dose of dobutamine is a safe and well tolerated method of performing stress echocardiography in patients with suspected or known coronary artery disease. This new protocol requires the administration of lower cumulative dobutamine dose than standard protocol and results in a significant reduction in test time.

  13. Dysregulated physiological stress systems and accelerated cellular aging.

    Révész, Dóra; Verhoeven, Josine E; Milaneschi, Yuri; de Geus, Eco J C N; Wolkowitz, Owen M; Penninx, Brenda W J H

    2014-06-01

    Exposure to chronic stressors is associated with accelerated biological aging as indicated by reduced leukocyte telomere length (LTL). This impact could be because of chronic overactivation of the body's physiological stress systems. This study examined the associations between LTL and the immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system. LTL was assessed in 2936 adults from the Netherlands Study of Depression and Anxiety. Inflammation markers (interleukin-6, c-reactive protein, tumor necrosis factor-alpha), hypothalamic-pituitary-adrenal-axis indicators (salivary cortisol awakening curve [area under the curve indicators, with respect to the ground and increase], evening levels, 0.5 mg dexamethasone cortisol suppression ratio), and autonomic nervous system measures (heart rate, respiratory sinus arrhythmia, pre-ejection period) were determined. Linear regression analyses were performed and adjusted for sociodemographic, lifestyle and clinical factors. Shorter LTL was significantly associated with higher c-reactive protein, interleukin-6, area under the curve with respect to increase, and heart rate. A cumulative index score was calculated based on the number of highest tertiles of these 4 stress markers. LTL demonstrated a significant gradient within subjects ranging from having zero (5528 base pairs) to having 4 elevated stress markers (5371 base pairs, p for trend = 0.002), corresponding to a difference of 10 years of accelerated biological aging. Contrary to the expectations, shorter LTL was also associated with longer pre-ejection period, indicating lower sympathetic tone. This large-scale study showed that inflammation, high awakening cortisol response, and increased heart rate are associated with shorter LTL, especially when they are dysregulated cumulatively. Copyright © 2014 Elsevier Inc. All rights reserved.

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

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

    2016-09-01

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

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

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

    2010-01-01

    index and the grade of osteophytes was 0.5 (p < 0.01) and 0.7 (p < 0.01) respectively. Spiking of the lateral tibial intercondylar spine is associated with osteophyte formation and osteoarthritis. Eburnation occurs mainly in the posterior parts of the tibial plateaus while osteophytes arise mainly in the anterior parts. These findings suggest that stresses occurring in the flexed knee may contribute to many of the morphological abnormalities of osteoarthritis. (orig.)

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

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

    2010-09-15

    intercondylar tibial spine index and the grade of osteophytes was 0.5 (p < 0.01) and 0.7 (p < 0.01) respectively. Spiking of the lateral tibial intercondylar spine is associated with osteophyte formation and osteoarthritis. Eburnation occurs mainly in the posterior parts of the tibial plateaus while osteophytes arise mainly in the anterior parts. These findings suggest that stresses occurring in the flexed knee may contribute to many of the morphological abnormalities of osteoarthritis. (orig.)

  17. Accelerated stress testing of amorphous silicon solar cells

    Stoddard, W. G.; Davis, C. W.; Lathrop, J. W.

    1985-01-01

    A technique for performing accelerated stress tests of large-area thin a-Si solar cells is presented. A computer-controlled short-interval test system employing low-cost ac-powered ELH illumination and a simulated a-Si reference cell (seven individually bandpass-filtered zero-biased crystalline PIN photodiodes) calibrated to the response of an a-Si control cell is described and illustrated with flow diagrams, drawings, and graphs. Preliminary results indicate that while most tests of a program developed for c-Si cells are applicable to a-Si cells, spurious degradation may appear in a-Si cells tested at temperatures above 130 C.

  18. Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

    Patterson, Timothy [Research Engineer; Motupally, Sathya [Research Engineer

    2012-06-01

    UTC will led a top-tier team of industry and national laboratory participants to update and improve DOE’s Accelerated Stress Tests (AST’s) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion® 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE AST’s. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new AST’s were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

  19. Tibial Plateau Fractures

    Elsøe, Rasmus

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

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

    Kei Osano

    2014-01-01

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

  1. Tibial hyperostosis: A diagnostic approach

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

    2013-01-01

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

  2. Tibial hyperostosis: A diagnostic approach

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

    2013-12-01

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

  3. Medical Standards for Experimental Human Use in Acceleration Stress Research

    1983-01-01

    or re- teroposterior and lateral X-rays of the cervical , thoracic, sources, we consider a positive treadmill test to be dis- and lumbar spine. These...Gz stress. The requirement for a complete cervical , thoracic and dividuals who developed significant stress dysrhythmias lumbar spine X-ray series...hematoma h. Hernia Ill. Cardiac Stress: a. Dywrhythmla (Tachyarrhythmias and Bradyarrhythmim) b. Heart blocks c. Stress caadlomyopmt U244 Awono. spme

  4. Optimal design of constant-stress accelerated degradation tests using the M-optimality criterion

    Wang, Han; Zhao, Yu; Ma, Xiaobing; Wang, Hongyu

    2017-01-01

    In this paper, we propose the M-optimality criterion for designing constant-stress accelerated degradation tests (ADTs). The newly proposed criterion concentrates on the degradation mechanism equivalence rather than evaluation precision or prediction accuracy which is usually considered in traditional optimization criteria. Subject to the constraints of total sample number, test termination time as well as the stress region, an optimum constant-stress ADT plan is derived by determining the combination of stress levels and the number of samples allocated to each stress level, when the degradation path comes from inverse Gaussian (IG) process model with covariates and random effects. A numerical example is presented to verify the robustness of our proposed optimum plan and compare its efficiency with other test plans. Results show that, with a slightly relaxed requirement of evaluation precision and prediction accuracy, our proposed optimum plan reduces the dispersion of the estimated acceleration factor between the usage stress level and a higher accelerated stress level, which makes an important contribution to reliability demonstration and assessment tests. - Highlights: • We establish the necessary conditions for degradation mechanism equivalence of ADTs. • We propose the M-optimality criterion for designing constant-stress ADT plans. • The M-optimality plan reduces the dispersion of the estimated accelerated factors. • An electrical connector with its stress relaxation data is used for illustration.

  5. Effect of initial longitudinal stresses on the linearity of the shape rolled products after accelerated cooling

    Shetulov, D.I.

    1991-01-01

    Consideration is given to results of investigation into effect of initial longitudinal stresses on the linearity of the shaped rolled products after accelerated cooling. Particular attention is placed on the influence of an initial stresses state of material on qualiti of heat-treated rolled products. Effect of stresses state of worked material residual bending is studed by the use of computerized simulation.Theoretical analysis of stress-strain state of shape hot-rolled products during accelerated cooling after finishing stand of rolls is developed. A residual stress-strain state of material does not affected by rolling stresses when using a rautine cooling device with rigid centering of the product under rolling. It is expected that the effect of initial stresses could be significant in the absence of a limitator for bending deformation of shaped product longitudinal axis

  6. Radiative processes for Rindler and accelerating observers and the stress-tensor detector

    Paola, R. De; Svaiter, N.F.

    1996-04-01

    It is considered a monopole detector interacting with a massive scalar field. Using the rotating wave approximation the radiative processes is discussed from the accelerated frame point of view. After this, it is obtained the Minkowski vacuum stress tensor measured by the accelerated observer using a non-gravitational stress sensor detector. Finally we analyse radiative processes of the monopole detector travelling in a world line that is inertial in the infinite past and has a constant proper acceleration in the infinite future. (author). 30 refs

  7. Safety of a rapid diagnostic protocol with accelerated stress testing.

    Soremekun, Olan A; Hamedani, Azita; Shofer, Frances S; O'Conor, Katie J; Svenson, James; Hollander, Judd E

    2014-02-01

    Most patients at low to intermediate risk for an acute coronary syndrome (ACS) receive a 12- to 24-hour "rule out." Recently, trials have found that a coronary computed tomographic angiography-based strategy is more efficient. If stress testing were performed within the same time frame as coronary computed tomographic angiography, the 2 strategies would be more similar. We tested the hypothesis that stress testing can safely be performed within several hours of presentation. We performed a retrospective cohort study of patients presenting to a university hospital from January 1, 2009, to December 31, 2011, with potential ACS. Patients placed in a clinical pathway that performed stress testing after 2 negative troponin values 2 hours apart were included. We excluded patients with ST-elevation myocardial infarction or with an elevated initial troponin. The main outcome was safety of immediate stress testing defined as the absence of death or acute myocardial infarction (defined as elevated troponin within 24 hours after the test). A total of 856 patients who presented with potential ACS were enrolled in the clinical pathway and included in this study. Patients had a median age of 55.0 (interquartile range, 48-62) years. Chest pain was the chief concern in 86%, and pain was present on arrival in 73% of the patients. There were no complications observed during the stress test. There were 0 deaths (95% confidence interval, 0%-0.46%) and 4 acute myocardial infarctions within 24 hours (0.5%; 95% confidence interval, 0.14%-1.27%). The peak troponins were small (0.06, 0.07, 0.07, and 0.19 ng/mL). Patients who present to the ED with potential ACS can safely undergo a rapid diagnostic protocol with stress testing. © 2013.

  8. Laser-accelerated particle beams for stress testing of materials.

    Barberio, M; Scisciò, M; Vallières, S; Cardelli, F; Chen, S N; Famulari, G; Gangolf, T; Revet, G; Schiavi, A; Senzacqua, M; Antici, P

    2018-01-25

    Laser-driven particle acceleration, obtained by irradiation of a solid target using an ultra-intense (I > 10 18  W/cm 2 ) short-pulse (duration testing materials and are particularly suited for identifying materials to be used in harsh conditions. We show that these laser-generated protons can produce, in a very short time scale, a strong mechanical and thermal damage, that, given the short irradiation time, does not allow for recovery of the material. We confirm this by analyzing changes in the mechanical, optical, electrical, and morphological properties of five materials of interest to be used in harsh conditions.

  9. Traumatic stress and accelerated DNA methylation age: A meta-analysis.

    Wolf, Erika J; Maniates, Hannah; Nugent, Nicole; Maihofer, Adam X; Armstrong, Don; Ratanatharathorn, Andrew; Ashley-Koch, Allison E; Garrett, Melanie; Kimbrel, Nathan A; Lori, Adriana; Va Mid-Atlantic Mirecc Workgroup; Aiello, Allison E; Baker, Dewleen G; Beckham, Jean C; Boks, Marco P; Galea, Sandro; Geuze, Elbert; Hauser, Michael A; Kessler, Ronald C; Koenen, Karestan C; Miller, Mark W; Ressler, Kerry J; Risbrough, Victoria; Rutten, Bart P F; Stein, Murray B; Ursano, Robert J; Vermetten, Eric; Vinkers, Christiaan H; Uddin, Monica; Smith, Alicia K; Nievergelt, Caroline M; Logue, Mark W

    2018-06-01

    Recent studies examining the association between posttraumatic stress disorder (PTSD) and accelerated aging, as defined by DNA methylation-based estimates of cellular age that exceed chronological age, have yielded mixed results. We conducted a meta-analysis of trauma exposure and PTSD diagnosis and symptom severity in association with accelerated DNA methylation age using data from 9 cohorts contributing to the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup (combined N = 2186). Associations between demographic and cellular variables and accelerated DNA methylation age were also examined, as was the moderating influence of demographic variables. Meta-analysis of regression coefficients from contributing cohorts revealed that childhood trauma exposure (when measured with the Childhood Trauma Questionnaire) and lifetime PTSD severity evidenced significant, albeit small, meta-analytic associations with accelerated DNA methylation age (ps = 0.028 and 0.016, respectively). Sex, CD4T cell proportions, and natural killer cell proportions were also significantly associated with accelerated DNA methylation age (all ps age. There was no evidence of moderation of the trauma or PTSD variables by demographic factors. Results suggest that traumatic stress is associated with advanced epigenetic age and raise the possibility that cells integral to immune system maintenance and responsivity play a role in this. This study highlights the need for additional research into the biological mechanisms linking traumatic stress to accelerated DNA methylation age and the importance of furthering our understanding of the neurobiological and health consequences of PTSD. Published by Elsevier Ltd.

  10. A Study on the Storage Reliability of LSINS Based on Step-stress Accelerated Life Test

    Teng Fei

    2015-01-01

    Full Text Available Based on the step-stress accelerated life test and the laser strap-down inertial navigation system, this paper studies the accelerated life model and the test method, provides the likelihood function, the likelihood equation and the two-order derivative when the stress level is k, evaluates the effectiveness of the method with the simulation test model established by MATLAB, applies the research findings in the storage reliability study of the XX laser strap-down inertial navigation system, and puts forward an effective evaluation method of the storage life of the inertial navigation system.

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

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

    2011-03-01

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

  12. FEM Techniques for High Stress Detection in Accelerated Fatigue Simulation

    Veltri, M.

    2016-09-01

    This work presents the theory and a numerical validation study in support to a novel method for a priori identification of fatigue critical regions, with the aim to accelerate durability design in large FEM problems. The investigation is placed in the context of modern full-body structural durability analysis, where a computationally intensive dynamic solution could be required to identify areas with potential for fatigue damage initiation. The early detection of fatigue critical areas can drive a simplification of the problem size, leading to sensible improvement in solution time and model handling while allowing processing of the critical areas in higher detail. The proposed technique is applied to a real life industrial case in a comparative assessment with established practices. Synthetic damage prediction quantification and visualization techniques allow for a quick and efficient comparison between methods, outlining potential application benefits and boundaries.

  13. Fraturas do planalto tibial Tibial plateau fractures

    Maurício Kfuri Júnior

    2009-01-01

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

  14. Bayesian Approach for Constant-Stress Accelerated Life Testing for Kumaraswamy Weibull Distribution with Censoring

    Abeer Abd-Alla EL-Helbawy

    2016-09-01

    Full Text Available The accelerated life tests provide quick information on the life time distributions by testing materials or products at higher than basic conditional levels of stress such as pressure, high temperature, vibration, voltage or load to induce failures. In this paper, the acceleration model assumed is log linear model. Constant stress tests are discussed based on Type I and Type II censoring. The Kumaraswmay Weibull distribution is used. The estimators of the parameters, reliability, hazard rate functions and p-th percentile at normal condition, low stress, and high stress are obtained. In addition, credible intervals for parameters of the models are constructed. Optimum test plan are designed. Some numerical studies are used to solve the complicated integrals such as Laplace and Markov Chain Monte Carlo methods.

  15. Bayesian Approach for Constant-Stress Accelerated Life Testing for Kumaraswamy Weibull Distribution with Censoring

    Abeer Abd-Alla EL-Helbawy

    2016-12-01

    Full Text Available The accelerated life tests provide quick information on the life time distributions by testing materials or products at higher than basic conditional levels of stress such as pressure, high temperature, vibration, voltage or load to induce failures. In this paper, the acceleration model assumed is log linear model. Constant stress tests are discussed based on Type I and Type II censoring. The Kumaraswmay Weibull distribution is used. The estimators of the parameters, reliability, hazard rate functions and p-th percentile at normal condition, low stress, and high stress are obtained. In addition, credible intervals for parameters of the models are constructed. Optimum test plan are designed. Some numerical studies are used to solve the complicated integrals such as Laplace and Markov Chain Monte Carlo methods.

  16. [Magnetic resonance imaging of tibial periostitis].

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

    1998-01-01

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

  17. Voltage stress effects on microcircuit accelerated life test failure rates

    Johnson, G. M.

    1976-01-01

    The applicability of Arrhenius and Eyring reaction rate models for describing microcircuit aging characteristics as a function of junction temperature and applied voltage was evaluated. The results of a matrix of accelerated life tests with a single metal oxide semiconductor microcircuit operated at six different combinations of temperature and voltage were used to evaluate the models. A total of 450 devices from two different lots were tested at ambient temperatures between 200 C and 250 C and applied voltages between 5 Vdc and 15 Vdc. A statistical analysis of the surface related failure data resulted in bimodal failure distributions comprising two lognormal distributions; a 'freak' distribution observed early in time, and a 'main' distribution observed later in time. The Arrhenius model was shown to provide a good description of device aging as a function of temperature at a fixed voltage. The Eyring model also appeared to provide a reasonable description of main distribution device aging as a function of temperature and voltage. Circuit diagrams are shown.

  18. Increased rate of acceleration on Pine Island Glacier strongly coupled to changes in gravitational driving stress

    J. B. T. Scott

    2009-05-01

    Full Text Available Pine Island Glacier, Antarctica, has been undergoing several related changes for at least two decades; these include acceleration, thinning and grounding line retreat. During the first major ground-based study between 2006 and 2008, GPS receivers were used to monitor ice flow from 55 km to 171 km inland, along the central flowline. At four sites both acceleration and thinning rates over the last two years exceeded rates observed at any other time over the last two decades. At the downstream site acceleration was 6.4% over 2007 and thinning was 3.5±0.5 ma−1. Acceleration and thinning have spread rapidly inland with the acceleration 171 km inland at 4.1% over 2007, greater than any measured annual flow increase along the whole glacier prior to 2006. Increases in surface slope, and hence gravitational driving stress, correlate well with the acceleration and no sustained change in longitudinal stress gradient is needed to explain the force balance. There is no indication that the glacier is approaching a new steady state.

  19. Quantum corrections to the stress-energy tensor in thermodynamic equilibrium with acceleration

    Becattini, F.; Grossi, E.

    2015-08-01

    We show that the stress-energy tensor has additional terms with respect to the ideal form in states of global thermodynamic equilibrium in flat spacetime with nonvanishing acceleration and vorticity. These corrections are of quantum origin and their leading terms are second order in the gradients of the thermodynamic fields. Their relevant coefficients can be expressed in terms of correlators of the stress-energy tensor operator and the generators of the Lorentz group. With respect to previous assessments, we find that there are more second-order coefficients and that all thermodynamic functions including energy density receive acceleration and vorticity dependent corrections. Notably, also the relation between ρ and p , that is, the equation of state, is affected by acceleration and vorticity. We have calculated the corrections for a free real scalar field—both massive and massless—and we have found that they increase, particularly for a massive field, at very high acceleration and vorticity and very low temperature. Finally, these nonideal terms depend on the explicit form of the stress-energy operator, implying that different stress-energy tensors of the scalar field—canonical or improved—are thermodynamically inequivalent.

  20. Accelerated Aging during Chronic Oxidative Stress: A Role for PARP-1

    Daniëlle M. P. H. J. Boesten

    2013-01-01

    Full Text Available Oxidative stress plays a major role in the pathophysiology of chronic inflammatory disease and it has also been linked to accelerated telomere shortening. Telomeres are specialized structures at the ends of linear chromosomes that protect these ends from degradation and fusion. Telomeres shorten with each cell division eventually leading to cellular senescence. Research has shown that poly(ADP-ribose polymerase-1 (PARP-1 and subtelomeric methylation play a role in telomere stability. We hypothesized that PARP-1 plays a role in accelerated aging in chronic inflammatory diseases due to its role as coactivator of NF-κb and AP-1. Therefore we evaluated the effect of chronic PARP-1 inhibition (by fisetin and minocycline in human fibroblasts (HF cultured under normal conditions and under conditions of chronic oxidative stress, induced by tert-butyl hydroperoxide (t-BHP. Results showed that PARP-1 inhibition under normal culturing conditions accelerated the rate of telomere shortening. However, under conditions of chronic oxidative stress, PARP-1 inhibition did not show accelerated telomere shortening. We also observed a strong correlation between telomere length and subtelomeric methylation status of HF cells. We conclude that chronic PARP-1 inhibition appears to be beneficial in conditions of chronic oxidative stress but may be detrimental under relatively normal conditions.

  1. Accelerators

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  2. Accelerating action of stresses on crystallization kinetics in silicon ion-implanted layers during pulsed heating

    Aleksandrov, L.N.

    1985-01-01

    Numerical simulation of the effect of stressed in ion-implanted layers on kinetics of amorphous phase transformations is performed. The suggested model of accounting stresses including concentration ones is based on the locality of action of interstitial addition atoms and on general structural inhomogeneity of amorphous semiconductor leading to the formation of areas of the facilitated phase transition. Accounting of effect of energy variation of silicon atoms interaction on probability of displacement events and atoms building in lattice points or atomic bonds disintegration allows one to trace the accelerating action of introduced by ion implantation stresses on the kinetics of layer crystallization during pulsed heating

  3. Collagen turnover after tibial fractures

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

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

  4. Medial tibial pain. A prospective study of its cause among military recruits.

    Milgrom, C; Giladi, M; Stein, M; Kashtan, H; Margulies, J; Chisin, R; Steinberg, R; Swissa, A; Aharonson, Z

    1986-12-01

    In a prospective study of 295 infantry recruits during 14 weeks of basic training, 41% had medial tibial pain. Routine scintigraphic evaluation in cases of medial tibial bone pain showed that 63% had abnormalities. A stress fracture was found in 46%. Only two patients had periostitis. None had ischemic medial compartment syndrome. Physical examination could not differentiate between cases with medial tibial bone pain secondary to stress fractures and those with scintigraphically normal tibias. When both pain and swelling were localized in the middle one-third of the tibia, the lesion most likely proved to be a stress fracture.

  5. Accelerated stress testing of thin film solar cells: Development of test methods and preliminary results

    Lathrop, J. W.

    1985-01-01

    If thin film cells are to be considered a viable option for terrestrial power generation their reliability attributes will need to be explored and confidence in their stability obtained through accelerated testing. Development of a thin film accelerated test program will be more difficult than was the case for crystalline cells because of the monolithic construction nature of the cells. Specially constructed test samples will need to be fabricated, requiring committment to the concept of accelerated testing by the manufacturers. A new test schedule appropriate to thin film cells will need to be developed which will be different from that used in connection with crystalline cells. Preliminary work has been started to seek thin film schedule variations to two of the simplest tests: unbiased temperature and unbiased temperature humidity. Still to be examined are tests which involve the passage of current during temperature and/or humidity stress, either by biasing in the forward (or reverse) directions or by the application of light during stress. Investigation of these current (voltage) accelerated tests will involve development of methods of reliably contacting the thin conductive films during stress.

  6. Tibial valgus aperture osteotomy

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

    2005-01-01

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

  7. Accelerated aging in schizophrenia patients: the potential role of oxidative stress.

    Okusaga, Olaoluwa O

    2014-08-01

    Several lines of evidence suggest that schizophrenia, a severe mental illness characterized by delusions, hallucinations and thought disorder is associated with accelerated aging. The free radical (oxidative stress) theory of aging assumes that aging occurs as a result of damage to cell constituents and connective tissues by free radicals arising from oxygen-associated reactions. Schizophrenia has been associated with oxidative stress and chronic inflammation, both of which also appear to reciprocally induce each other in a positive feedback manner. The buildup of damaged macromolecules due to increased oxidative stress and failure of protein repair and maintenance systems is an indicator of aging both at the cellular and organismal level. When compared with age-matched healthy controls, schizophrenia patients have higher levels of markers of oxidative cellular damage such as protein carbonyls, products of lipid peroxidation and DNA hydroxylation. Potential confounders such as antipsychotic medication, smoking, socio-economic status and unhealthy lifestyle make it impossible to solely attribute the earlier onset of aging-related changes or oxidative stress to having a diagnosis of schizophrenia. Regardless of whether oxidative stress can be attributed solely to a diagnosis of schizophrenia or whether it is due to other factors associated with schizophrenia, the available evidence is in support of increased oxidative stress-induced cellular damage of macromolecules which may play a role in the phenomenon of accelerated aging presumed to be associated with schizophrenia.

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

    Ristiniemi, Jukka

    2007-06-01

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

  9. The SAT Protein of Porcine Parvovirus Accelerates Viral Spreading through Induction of Irreversible Endoplasmic Reticulum Stress.

    Mészáros, István; Tóth, Renáta; Olasz, Ferenc; Tijssen, Peter; Zádori, Zoltán

    2017-08-15

    The SAT protein (SATp) of porcine parvovirus (PPV) accumulates in the endoplasmic reticulum (ER), and SAT deletion induces the slow-spreading phenotype. The in vitro comparison of the wild-type Kresse strain and its SAT knockout (SAT - ) mutant revealed that prolonged cell integrity and late viral release are responsible for the slower spreading of the SAT - virus. During PPV infection, regardless of the presence or absence of SATp, the expression of downstream ER stress response proteins (Xbp1 and CHOP) was induced. However, in the absence of SATp, significant differences in the quantity and the localization of CHOP were detected, suggesting a role of SATp in the induction of irreversible ER stress in infected cells. The involvement of the induction of irreversible ER stress in porcine testis (PT) cell necrosis and viral egress was confirmed by treatment of infected cells by ER stress-inducing chemicals (MG132, dithiothreitol, and thapsigargin), which accelerated the egress and spreading of both the wild-type and the SAT - viruses. UV stress induction had no beneficial effect on PPV infection, underscoring the specificity of ER stress pathways in the process. However, induction of CHOP and its nuclear translocation cannot alone be responsible for the biological effect of SAT, since nuclear CHOP could not complement the lack of SAT in a coexpression experiment. IMPORTANCE SATp is encoded by an alternative open reading frame of the PPV genome. Earlier we showed that SATp of the attenuated PPV NADL-2 strain accumulates in the ER and accelerates virus release and spreading. Our present work revealed that slow spreading is a general feature of SAT - PPVs and is the consequence of prolonged cell integrity. PPV infection induced ER stress in infected cells regardless of the presence of SATp, as demonstrated by the morphological changes of the ER and expression of the stress response proteins Xbp1 and CHOP. However, the presence of SATp made the ER stress more severe and

  10. Are malnutrition and stress risk factors for accelerated cognitive decline? A prisoner of war study.

    Sulway, M R; Broe, G A; Creasey, H; Dent, O F; Jorm, A F; Kos, S C; Tennant, C C

    1996-03-01

    We set out to test the hypothesis that severe malnutrition and stress experienced by prisoners of war (POWs) are associated with cognitive deficits later in life. We assessed 101 former Australian POWs of the Japanese and 108 veteran control subjects using a battery of neuropsychological tests, a depression scale, a clinical examination for dementia, and CT. We divided the POWs into high weight loss (>35%) and low weight loss groups (malnutrition is a risk factor for accelerated cognitive decline nor the theory that severe stress can lead to hippocampal neuronal loss and cognitive deficits. Cognitive deficits in earlier studies of former POWs may have been associated with concurrent depression.

  11. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    Zhang, Jianping, E-mail: jpzhanglzu@163.com [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Wenbin [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Cheng, Guoliang; Chen, Xiao [Shanghai Tianyi Electric Co., Ltd., Shanghai 201611 (China); Wu, Helen [School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney 2751 (Australia); Herman Shen, M.-H. [Department of Mechanical and Aerospace Engineering, The Ohio State University, OH 43210 (United States)

    2014-10-15

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high.

  12. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    Zhang, Jianping; Li, Wenbin; Cheng, Guoliang; Chen, Xiao; Wu, Helen; Herman Shen, M.-H.

    2014-01-01

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high

  13. Obesity-induced oxidative stress, accelerated functional decline with age and increased mortality in mice.

    Zhang, Yiqiang; Fischer, Kathleen E; Soto, Vanessa; Liu, Yuhong; Sosnowska, Danuta; Richardson, Arlan; Salmon, Adam B

    2015-06-15

    Obesity is a serious chronic disease that increases the risk of numerous co-morbidities including metabolic syndrome, cardiovascular disease and cancer as well as increases risk of mortality, leading some to suggest this condition represents accelerated aging. Obesity is associated with significant increases in oxidative stress in vivo and, despite the well-explored relationship between oxidative stress and aging, the role this plays in the increased mortality of obese subjects remains an unanswered question. Here, we addressed this by undertaking a comprehensive, longitudinal study of a group of high fat-fed obese mice and assessed both their changes in oxidative stress and in their performance in physiological assays known to decline with aging. In female C57BL/6J mice fed a high-fat diet starting in adulthood, mortality was significantly increased as was oxidative damage in vivo. High fat-feeding significantly accelerated the decline in performance in several assays, including activity, gait, and rotarod. However, we also found that obesity had little effect on other markers of function and actually improved performance in grip strength, a marker of muscular function. Together, this first comprehensive assessment of longitudinal, functional changes in high fat-fed mice suggests that obesity may induce segmental acceleration of some of the aging process. Published by Elsevier Inc.

  14. Design of PH-based accelerated life testing plans under multiple-stress-type

    Elsayed, E.A.; Zhang Hao

    2007-01-01

    Accelerated life testing (ALT) is used to obtain failure time data quickly under high stress levels in order to predict product life performance under design stress conditions. Most of the previous work on designing ALT plans is focused on the application of a single stress. However, as components or products become more reliable due to technological advances, it becomes more difficult to obtain significant amount of failure data within reasonable amount of time using single stress only. Multiple-stress-type ALTs have been employed as a means of overcoming such difficulties. In this paper, we design optimum multiple-stress-type ALT plans based on the proportional hazards model. The optimum combinations of stresses and their levels are determined such that the variance of the reliability estimate of the product over a specified period of time is minimized. The use of the model is illustrated using numerical example, and sensitivity analysis shows that the resultant optimum ALT plan is robust to the deviation in model parameters

  15. Do stress fractures induce hypertrophy of the grafted fibula? A report of three cases received free vascularized fibular graft treatment for tibial defects.

    Qi, Yong; Sun, Hong-Tao; Fan, Yue-Guang; Li, Fei-Meng; Lin, Zhou-Sheng

    2016-06-01

    The presence of large segmental defects of the diaphyseal bone is challenging for orthopedic surgeons. Free vascularized fibular grafting (FVFG) is considered to be a reliable reconstructive procedure. Stress fractures are a common complication following this surgery, and hypertrophy is the main physiological change of the grafted fibula. The exact mechanism of hypertrophy is not completely known. To the best of our knowledge, no studies have examined the possible relationship between stress fractures and hypertrophy. We herein report three cases of patients underwent FVFG. Two of them developed stress fractures and significant hypertrophy, while the remaining patient developed neither stress fractures nor significant hypertrophy. This phenomenon indicates that a relationship may exist between stress fractures and hypertrophy of the grafted fibula, specifically, that the presence of a stress fracture may initiate the process of hypertrophy.

  16. Repeated restraint stress exposure during early withdrawal accelerates incubation of cue-induced cocaine craving.

    Glynn, Ryan M; Rosenkranz, J Amiel; Wolf, Marina E; Caccamise, Aaron; Shroff, Freya; Smith, Alyssa B; Loweth, Jessica A

    2018-01-01

    A major challenge for treating cocaine addiction is the propensity for abstinent users to relapse. Two important triggers for relapse are cues associated with prior drug use and stressful life events. To study their interaction in promoting relapse during abstinence, we used the incubation model of craving and relapse in which cue-induced drug seeking progressively intensifies ('incubates') during withdrawal from extended-access cocaine self-administration. We tested rats for cue-induced cocaine seeking on withdrawal day (WD) 1. Rats were then subjected to repeated restraint stress or control conditions (seven sessions held between WD6 and WD14). All rats were tested again for cue-induced cocaine seeking on WD15, 1 day after the last stress or control session. Although controls showed a time-dependent increase in cue-induced cocaine seeking (incubation), rats exposed to repeated stress in early withdrawal exhibited a more robust increase in seeking behavior between WD1 and WD15. In separate stressed and control rats, equivalent cocaine seeking was observed on WD48. These results indicate that repeated stress in early withdrawal accelerates incubation of cocaine craving, although craving plateaus at the same level were observed in controls. However, 1 month after the WD48 test, rats subjected to repeated stress in early withdrawal showed enhanced cue-induced cocaine seeking following acute (24 hours) food deprivation stress. Together, these data indicate that chronic stress exposure enhances the initial rate of incubation of craving during early withdrawal, resulting in increased vulnerability to cue-induced relapse during this period, and may lead to a persistent increase in vulnerability to the relapse-promoting effects of stress. © 2016 Society for the Study of Addiction.

  17. Testing the accelerating moment release (AMR) hypothesis in areas of high stress

    Guilhem, Aurélie; Bürgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez

    2013-11-01

    Several retrospective analyses have proposed that significant increases in moment release occurred prior to many large earthquakes of recent times. However, the finding of accelerating moment release (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the seismicity of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-seismic relaxation, and the interseismic strain accumulation. We find no convincing correlation of seismicity rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.

  18. Early life stress accelerates behavioral and neural maturation of the hippocampus in male mice.

    Bath, K; Manzano-Nieves, G; Goodwill, H

    2016-06-01

    Early life stress (ELS) increases the risk for later cognitive and emotional dysfunction. ELS is known to truncate neural development through effects on suppressing cell birth, increasing cell death, and altering neuronal morphology, effects that have been associated with behavioral profiles indicative of precocious maturation. However, how earlier silencing of growth drives accelerated behavioral maturation has remained puzzling. Here, we test the novel hypothesis that, ELS drives a switch from growth to maturation to accelerate neural and behavioral development. To test this, we used a mouse model of ELS, fragmented maternal care, and a cross-sectional dense sampling approach focusing on hippocampus and measured effects of ELS on the ontogeny of behavioral development and biomarkers of neural maturation. Consistent with previous work, ELS was associated with an earlier developmental decline in expression of markers of cell proliferation (Ki-67) and differentiation (doublecortin). However, ELS also led to a precocious arrival of Parvalbumin-positive cells, led to an earlier switch in NMDA receptor subunit expression (marker of synaptic maturity), and was associated with an earlier rise in myelin basic protein expression (key component of the myelin sheath). In addition, in a contextual fear-conditioning task, ELS accelerated the timed developmental suppression of contextual fear. Together, these data provide support for the hypothesis that ELS serves to switch neurodevelopment from processes of growth to maturation and promotes accelerated development of some forms of emotional learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. TIBIAL SHAFT FRACTURES.

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2011-01-01

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

  20. Study on constant-step stress accelerated life tests in white organic light-emitting diodes.

    Zhang, J P; Liu, C; Chen, X; Cheng, G L; Zhou, A X

    2014-11-01

    In order to obtain reliability information for a white organic light-emitting diode (OLED), two constant and one step stress tests were conducted with its working current increased. The Weibull function was applied to describe the OLED life distribution, and the maximum likelihood estimation (MLE) and its iterative flow chart were used to calculate shape and scale parameters. Furthermore, the accelerated life equation was determined using the least squares method, a Kolmogorov-Smirnov test was performed to assess if the white OLED life follows a Weibull distribution, and self-developed software was used to predict the average and the median lifetimes of the OLED. The numerical results indicate that white OLED life conforms to a Weibull distribution, and that the accelerated life equation completely satisfies the inverse power law. The estimated life of a white OLED may provide significant guidelines for its manufacturers and customers. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Salicylic acid alleviates decreases in photosynthesis under heat stress and accelerates recovery in grapevine leaves

    Cheng Jian-Shan

    2010-02-01

    Full Text Available Abstract Background Although the effect of salicylic acid (SA on photosynthesis of plants including grapevines has been investigated, very little is yet known about the effects of SA on carbon assimilation and several components of PSII electron transport (donor side, reaction center and acceptor side. In this study, the impact of SA pretreatment on photosynthesis was evaluated in the leaves of young grapevines before heat stress (25°C, during heat stress (43°C for 5 h, and through the following recovery period (25°C. Photosynthetic measures included gas exchange parameters, PSII electron transport, energy dissipation, and Rubisco activation state. The levels of heat shock proteins (HSPs in the chloroplast were also investigated. Results SA did not significantly (P Pn of leaves before heat stress. But, SA did alleviate declines in Pn and Rubisco activition state, and did not alter negative changes in PSII parameters (donor side, acceptor side and reaction center QA under heat stress. Following heat treatment, the recovery of Pn in SA-treated leaves was accelerated compared with the control (H2O-treated leaves, and, donor and acceptor parameters of PSII in SA-treated leaves recovered to normal levels more rapidly than in the controls. Rubisco, however, was not significantly (P Conclusion SA pretreatment alleviated the heat stress induced decrease in Pn mainly through maintaining higher Rubisco activition state, and it accelerated the recovery of Pn mainly through effects on PSII function. These effects of SA may be related in part to enhanced levels of HSP21.

  2. The role of oxidative and nitrosative stress in accelerated aging and major depressive disorder.

    Maurya, Pawan Kumar; Noto, Cristiano; Rizzo, Lucas B; Rios, Adiel C; Nunes, Sandra O V; Barbosa, Décio Sabbatini; Sethi, Sumit; Zeni, Maiara; Mansur, Rodrigo B; Maes, Michael; Brietzke, Elisa

    2016-02-04

    Major depressive disorder (MDD) affects millions of individuals and is highly comorbid with many age associated diseases such as diabetes mellitus, immune-inflammatory dysregulation and cardiovascular diseases. Oxidative/nitrosative stress plays a fundamental role in aging, as well as in the pathogenesis of neurodegenerative/neuropsychiatric disorders including MDD. In this review, we critically review the evidence for an involvement of oxidative/nitrosative stress in acceleration of aging process in MDD. There are evidence of the association between MDD and changes in molecular mechanisms involved in aging. There is a significant association between telomere length, enzymatic antioxidant activities (SOD, CAT, GPx), glutathione (GSH), lipid peroxidation (MDA), nuclear factor κB, inflammatory cytokines with MDD. Major depression also is characterized by significantly lower concentration of antioxidants (zinc, coenzyme Q10, PON1). Since, aging and MDD share a common biological base in their pathophysiology, the potential therapeutic use of antioxidants and anti-aging molecules in MDD could be promising.

  3. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  4. Optimal Constant-Stress Accelerated Degradation Test Plans Using Nonlinear Generalized Wiener Process

    Zhen Chen

    2016-01-01

    Full Text Available Accelerated degradation test (ADT has been widely used to assess highly reliable products’ lifetime. To conduct an ADT, an appropriate degradation model and test plan should be determined in advance. Although many historical studies have proposed quite a few models, there is still room for improvement. Hence we propose a Nonlinear Generalized Wiener Process (NGWP model with consideration of the effects of stress level, product-to-product variability, and measurement errors for a higher estimation accuracy and a wider range of use. Then under the constraints of sample size, test duration, and test cost, the plans of constant-stress ADT (CSADT with multiple stress levels based on the NGWP are designed by minimizing the asymptotic variance of the reliability estimation of the products under normal operation conditions. An optimization algorithm is developed to determine the optimal stress levels, the number of units allocated to each level, inspection frequency, and measurement times simultaneously. In addition, a comparison based on degradation data of LEDs is made to show better goodness-of-fit of the NGWP than that of other models. Finally, optimal two-level and three-level CSADT plans under various constraints and a detailed sensitivity analysis are demonstrated through examples in this paper.

  5. Blue lighting accelerates post-stress relaxation: Results of a preliminary study.

    Minguillon, Jesus; Lopez-Gordo, Miguel Angel; Renedo-Criado, Diego A; Sanchez-Carrion, Maria Jose; Pelayo, Francisco

    2017-01-01

    Several authors have studied the influence of light on both human physiology and emotions. Blue light has been proved to reduce sleepiness by suppression of melatonin secretion and it is also present in many emotion-related studies. Most of these have a common lack of objective methodology since results and conclusions are based on subjective perception of emotions. The aim of this work was the objective assessment of the effect of blue lighting in post-stress relaxation, in comparison with white lighting, by means of bio-signals and standardized procedures. We conducted a study in which twelve healthy volunteers were stressed and then performed a relaxation session within a chromotherapy room with blue (test group) or white (control group) lighting. We conclude that the blue lighting accelerates the relaxation process after stress in comparison with conventional white lighting. The relaxation time decreased by approximately three-fold (1.1 vs. 3.5 minutes). We also observed a convergence time (3.5-5 minutes) after which the advantage of blue lighting disappeared. This supports the relationship between color of light and stress, and the observations reported in previous works. These findings could be useful in clinical and educational environments, as well as in daily-life context and emerging technologies such as neuromarketing. However, our study must be extended to draw reliable conclusions and solid scientific evidence.

  6. Blue lighting accelerates post-stress relaxation: Results of a preliminary study.

    Jesus Minguillon

    Full Text Available Several authors have studied the influence of light on both human physiology and emotions. Blue light has been proved to reduce sleepiness by suppression of melatonin secretion and it is also present in many emotion-related studies. Most of these have a common lack of objective methodology since results and conclusions are based on subjective perception of emotions. The aim of this work was the objective assessment of the effect of blue lighting in post-stress relaxation, in comparison with white lighting, by means of bio-signals and standardized procedures. We conducted a study in which twelve healthy volunteers were stressed and then performed a relaxation session within a chromotherapy room with blue (test group or white (control group lighting. We conclude that the blue lighting accelerates the relaxation process after stress in comparison with conventional white lighting. The relaxation time decreased by approximately three-fold (1.1 vs. 3.5 minutes. We also observed a convergence time (3.5-5 minutes after which the advantage of blue lighting disappeared. This supports the relationship between color of light and stress, and the observations reported in previous works. These findings could be useful in clinical and educational environments, as well as in daily-life context and emerging technologies such as neuromarketing. However, our study must be extended to draw reliable conclusions and solid scientific evidence.

  7. Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

    Lathrop, J. W.; Prince, J. L.

    1980-04-01

    Three tasks were undertaken to investigate reliability attributes of terrestrial solar cells: (1) a study of the electrical behavior of cells in the second (reverse) quadrant; (2) the accelerated stress testing of three new state-of-the-art cells; and (3) the continued bias-temperature testing of four block 2 type silicon cells at 78 C and 135 C. Electrical characteristics measured in the second quadrant were determined to be a function of the cell's thermal behavior with breakdown depending on the initiation of localized heating. This implied that high breakdown cells may be more fault tolerant when forced to operate in the second quadrant, a result contrary to conventional thinking. The accelerated stress tests used in the first (power) quadrant were bias-temperature, bias-temperature-humidity, temperature-humidity, thermal shock, and thermal cycle. The new type cells measured included an EFG cell, a polycrystalline cell, and a Czochralski cell. Significant differences in the response to the various tests were observed between cell types. A microprocessed controlled, short interval solar cell tester was designed and construction initiated on a prototype.

  8. Major depressive disorder mediates accelerated aging in rats subjected to chronic mild stress.

    Xie, Xiaoxian; Chen, Yangyang; Ma, Lingyan; Shen, Qichen; Huang, Liangfeng; Zhao, Binggong; Wu, Tao; Fu, Zhengwei

    2017-06-30

    Major depressive disorder (MDD) has a complex etiology and is characterized by a change in mood and psychophysiological state. MDD has been shown to mediate accelerated biological aging in patients, although the underlying mechanism is not well understood. In the present study, we used a chronic mild stress (CMS) paradigm to induce anhedonia, one of the main symptoms of MDD. CMS induced depression-like symptoms in rats, including reduced sucrose preference and increased immobility time in the forced swim test. Moreover, stressed rats travelled a shorter total distance, had fewer grid line crossings, and spent less time in the outer zone in the open field test than controls. CMS altered the levels of 5-hydroxytryptophan, dopamine, and corticosterone in the serum and hippocampus (P<0.05); these rats also exhibited impaired liver function, decreased telomerase activity, and telomere shortening, which was associated with increased oxidative damage along with decreased superoxide dismutase and glutathione reductase activities. Mitochondria in CMS-treated rats showed ultrastructural damage as well as reduced DNA content and integrity. These findings provide physiological and cellular evidence that the MDD can mediate accelerated aging in rats. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Yohei Tanikake

    2016-12-01

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

  10. Chronic stress accelerates the development of endometriosis in mouse through adrenergic receptor β2.

    Long, Qiqi; Liu, Xishi; Qi, Qiuming; Guo, Sun-Wei

    2016-11-01

    Does chronic stress in mice accelerate the development of endometriosis, and, if so, through what mechanism? Exposure to chronic stress accelerates the development of endometriosis and exacerbates the endometriosis-associated generalized hyperalgesia, most likely through activation of the adrenoceptor β2 (ADRB2) and cAMP responsive element-binding protein (CREB). Women with endometriosis tend to have higher levels of psychological stress, which is known to impact negatively on health in general and to promote tumor growth and metastasis in particular. Exposure to chronic stress before and after the induction of endometriosis is reported to increase lesion sizes in rodents, but it is unclear whether adrenoceptors are involved or not in the stress-promoted development of endometriosis. Three independent, prospective, randomized mouse experimentations. A total of 184 virgin female Balb/C mice were used. In Experiment 1, the mice were randomly divided into four groups: the control group, which received no stress; the before, after and both groups, which received immobilization stress before, after and both before and after the induction of endometriosis, respectively. In Experiment 2, mice were randomly divided into four groups one day after the induction of endometriosis: phosphate buffer saline (PBS) and propranolol (PROP) groups, which received the mini-pump containing, respectively, PBS only and propranolol (a non-selective ADRB antagonist) but no stress, STR+PROP and STR+PBS groups, which received stress and the mini-pump containing, respectively, propranolol and PBS. The immobilization stress started after the insertion of mini-pumps. In Experiment 3, mice were induced with endometriosis. Three days after the induction, they were randomly divided into four groups: control, ADRAa, ADRB2a, and ADRBa, which received the mini-pump containing solution only, metaraminol (a non-specific α adrenoceptor agonist), tebutaline (a specific ADRB2 agonist), or isoproterenol

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

    Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

    2016-01-01

    A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed...

  12. Serpentine endophytic bacterium Pseudomonas azotoformans ASS1 accelerates phytoremediation of soil metals under drought stress.

    Ma, Ying; Rajkumar, Mani; Moreno, António; Zhang, Chang; Freitas, Helena

    2017-10-01

    This study evaluates the potential of serpentine endophytic bacterium to foster phytoremediation efficiency of Trifolium arvense grown on multi-metal (Cu, Zn and Ni) contaminated soils under drought stress. A drought resistant endophytic bacterial strain ASS1 isolated from the leaves of Alyssum serpyllifolium grown in serpentine soils was identified as Pseudomonas azotoformans based on biochemical tests and partial 16S rRNA gene sequencing. P. azotoformans ASS1 possessed abiotic stress resistance (heavy metals, drought, salinity, antibiotics and extreme temperature) and plant growth promoting (PGP) properties (phosphate solubilization, nitrogen fixation, production of 1-aminocyclopropane-1-carboxylate deaminase, siderophore and ammonia). Inoculation of T. arvense with ASS1 considerably increased the plant biomass and leaf relative water content in both roll towel assay and pot experiments in the absence and presence of drought stress (DS). In the pot experiments, ASS1 greatly enhanced chlorophyll content, catalase, peroxidase, superoxide dismutase activities, and proline content (only in the absence of drought) in plant leaves, whereas they decreased the concentrations of malondialdehyde. Irrespective of water stress, ASS1 significantly improved accumulation, total removal, bio-concentration factor and biological accumulation coefficient of metals (Cu, Zn and Ni), while decreased translocation factors of Cu. The effective colonization and survival in the rhizosphere and tissue interior assured improved plant growth and successful metal phytoremediation under DS. These results demonstrate the potential of serpentine endophytic bacterium ASS1 for protecting plants against abiotic stresses and helping plants to thrive in semiarid ecosystems and accelerate phytoremediation process in metal polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    J. Ryan Martin, MD

    2016-09-01

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

  14. A fiber optics sensor for strain and stress management in superconducting accelerator magnets

    van Oort, J.M.; ten Kate, H.H.J.

    1993-01-01

    A novel cryogenic interferometric fiber optics sensor for the measurement of strain and stress in the coil windings of superconducting accelerator magnets is described. The sensor can operate with two different readout sources, monochromatic laser light and white light respectively. The sensor head is built up as an extrinsic Fabry-Perot interferometer formed with two cleaved fiber surfaces, and can be mounted in several configurations. When read with laser light, the sensor is an extremely sensitive relative strain or temperature detector. When read with white light the absolute strain and pressure can be measured. Results are presented of tests in several configurations at 77 K and 4.2 K, both for the relative and absolute readout method. Finally, the possible use for quench localization using the temperature sensitivity is described

  15. Accelerated Stress Testing of Multi-Source LED Products: Horticulture Lamps and Tunable-White Modules

    Lynn Davis, Kelley Rountree, Karmann Mills

    2018-03-30

    This report discusses the use of accelerated stress testing (AST) to provide insights into the long-term behavior of commercial products utilizing different types of mid-power LEDs (MP-LEDs) integrated into the same LED module. Test results are presented from two commercial lamps intended for use in horticulture applications and one tunable-white LED module intended for use in educational and office lighting applications. Each of these products is designed to provide a custom spectrum for their targeted applications and each achieves this goal in different ways. Consequently, a comparison of the long-term stability of these devices will provide insights regarding approaches that could be used to possibly lengthen the lifetime of SSL products.

  16. [Autonomic regulation at emotional stress under hypoxic conditions in the elderly with physiological and accelerated aging: effect of hypoxic training].

    Os'mak, E D; Asanov, É O

    2014-01-01

    The effect of hypoxic training on autonomic regulation in psycho-emotional stress conditions in hypoxic conditions in older people with physiological (25 people) and accelerated (28 people) aging respiratory system. It is shown that hypoxic training leads to an increase in vagal activity indicators (HF) and reduced simpatovagal index (LF/HF), have a normalizing effect on the autonomic balance during stress loads in older people with different types of aging respiratory system.

  17. Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling.

    Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan; Zhao, Lisheng

    2016-03-25

    Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS.

  18. Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

    Jun Wan

    2014-01-01

    Conclusions: Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal preservation of ankle movements. Lengthening along with intramedullary nails may significantly reduce the external fixation time and the risk of fixator-related complications.

  19. Biomechanical Factors in Tibial Stress Fractures

    2004-08-01

    Science in Sports and Exercise. 22:2, S69, April, 1990. Ebbeling, C. J., Hamill, J., Freedson, P. S., Rowland, T. W. Metabolic and mechanical differences...Stability and the metabolic cost of human walking. XIth International Symposium on Posture and Gait: Control Mechanisms, Portland, OR, May, 1992. Li, L...extremity function, Isotechnologies, Inc., $12,000, 9/1982 - 6/1984. 2. Ergonomics of lower extremity function, KangaROOS , USA, $58,000, 9/1986 - 9

  20. All-Polyethylene Tibial Components: An Analysis of Long-Term Outcomes and Infection.

    Houdek, Matthew T; Wagner, Eric R; Wyles, Cody C; Watts, Chad D; Cass, Joseph R; Trousdale, Robert T

    2016-07-01

    There is debate regarding tibial component modularity and composition in total knee arthroplasty (TKA). Biomechanical studies have suggested improved stress distribution in metal-backed tibias; however, these results have not translated clinically. The purpose of this study was to analyze the outcomes of all-polyethylene components and to compare the results to those with metal-backed components. We reviewed 31,939 patients undergoing a primary TKA over a 43-year period (1970-2013). There were 28,224 (88%) metal-backed and 3715 (12%) all-polyethylene tibial components. The metal-backed and all-polyethylene groups had comparable demographics with respect to gender, age and body mass index (BMI). Mean follow-up was 7 years. The mean survival for all primary TKAs at the 5-, 10-, 20- and 30-year time points was 95%, 89%, 73%, and 57%, respectively. All-polyethylene tibial components were found to have a significantly improved (P tibial components were also found to have a significantly lower rate of infection, instability, tibial component loosening, and periprosthetic fracture. The all-polyethylene group had improved survival rates in all age groups, except in patients 85 years old or greater, where there was no significant difference. All-polyethylene tibial components had improved survival for all BMI groups except in the morbidly obese (BMI ≥ 40) where there was no significant difference. All-polyethylene tibial components had significantly improved implant survival, reduced rates of postoperative infection, fracture, and tibial component loosening. All polyethylene should be considered for most of the patients, regardless of age and BMI. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Incomplete linear tibial fractures in two horses

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

    1988-01-01

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

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

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

    2016-09-01

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

  3. Mechanical stresses and strains in superconducting dipole magnets for high energy accelerators

    Greben, L.I.; Mironov, E.S.; Moustafin, H.H.

    1979-01-01

    Stress and strain distributions in superconducting dipole magnets were investigated numerically. A finite element computer program was developed to calculate stresses and displacements due to thermal stress, electromagnetic forces and prestressing of structural elements. Real mechanical and thermal properties of superconducting dipole elements are taken into account. Numerical results of stress and strain patterns in dipole magnets are presented

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

    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.

  5. Bilateral double level tibial lengthening in dwarfism.

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

    2015-12-01

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

  6. Measurement of tibial torsion by computer tomography

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

    1981-01-01

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

  7. Measurement of tibial torsion by computer tomography

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

    1981-01-01

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

  8. Utility of cement injection to stabilize split-depression tibial plateau fracture by minimally invasive methods: A finite element analysis.

    Belaid, D; Vendeuvre, T; Bouchoucha, A; Brémand, F; Brèque, C; Rigoard, P; Germaneau, A

    2018-05-08

    Treatment for fractures of the tibial plateau is in most cases carried out by stable fixation in order to allow early mobilization. Minimally invasive technologies such as tibioplasty or stabilization by locking plate, bone augmentation and cement filling (CF) have recently been used to treat this type of fracture. The aim of this paper was to determine the mechanical behavior of the tibial plateau by numerically modeling and by quantifying the mechanical effects on the tibia mechanical properties from injury healing. A personalized Finite Element (FE) model of the tibial plateau from a clinical case has been developed to analyze stress distribution in the tibial plateau stabilized by balloon osteoplasty and to determine the influence of the cement injected. Stress analysis was performed for different stages after surgery. Just after surgery, the maximum von Mises stresses obtained for the fractured tibia treated with and without CF were 134.9 MPa and 289.9 MPa respectively on the plate. Stress distribution showed an increase of values in the trabecular bone in the treated model with locking plate and CF and stress reduction in the cortical bone in the model treated with locking plate only. The computed results of stresses or displacements of the fractured models show that the cement filling of the tibial depression fracture may increase implant stability, and decrease the loss of depression reduction, while the presence of the cement in the healed model renders the load distribution uniform. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

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

    2007-02-01

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

  10. Bypass grafting to the anterior tibial artery.

    Armour, R H

    1976-01-01

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

  11. Poor maternal nutrition and accelerated postnatal growth induces an accelerated aging phenotype and oxidative stress in skeletal muscle of male rats

    Jane L. Tarry-Adkins

    2016-10-01

    Full Text Available ‘Developmental programming’, which occurs as a consequence of suboptimal in utero and early environments, can be associated with metabolic dysfunction in later life, including an increased incidence of cardiovascular disease and type 2 diabetes, and predisposition of older men to sarcopenia. However, the molecular mechanisms underpinning these associations are poorly understood. Many conditions associated with developmental programming are also known to be associated with the aging process. We therefore utilized our well-established rat model of low birth weight and accelerated postnatal catch-up growth (termed ‘recuperated’ in this study to establish the effects of suboptimal maternal nutrition on age-associated factors in skeletal muscle. We demonstrated accelerated telomere shortening (a robust marker of cellular aging as evidenced by a reduced frequency of long telomeres (48.5-8.6 kb and an increased frequency of short telomeres (4.2-1.3 kb in vastus lateralis muscle from aged recuperated offspring compared to controls. This was associated with increased protein expression of the DNA-damage-repair marker 8-oxoguanine-glycosylase (OGG1 in recuperated offspring. Recuperated animals also demonstrated an oxidative stress phenotype, with decreased citrate synthase activity, increased electron-transport-complex activities of complex I, complex II-III and complex IV (all markers of functional mitochondria, and increased xanthine oxidase (XO, p67phox and nuclear-factor kappa-light-chain-enhancer of activated B-cells (NF-κB. Recuperated offspring also demonstrated increased antioxidant defense capacity, with increased protein expression of manganese superoxide dismutase (MnSOD, copper-zinc superoxide dismutase (CuZnSOD, catalase and heme oxygenase-1 (HO1, all of which are known targets of NF-κB and can be upregulated as a consequence of oxidative stress. Recuperated offspring also had a pro-inflammatory phenotype, as evidenced by

  12. Fracture of a Polyethylene Tibial Post in a Scorpio Posterior-Stabilized Knee Prosthesis

    Lim, Hong Chul; Bae, Ji Hoon; Hwang, Jin Ho; Kim, Seung Joo; Yoon, Ji Yeol

    2009-01-01

    We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articu...

  13. Incidence and epidemiology of tibial shaft fractures.

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

    2015-04-01

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

  14. Understanding How Kurtosis Is Transferred from Input Acceleration to Stress Response and Its Influence on Fatigue Llife

    Kihm, Frederic; Rizzi, Stephen A.; Ferguson, Neil S.; Halfpenny, Andrew

    2013-01-01

    High cycle fatigue of metals typically occurs through long term exposure to time varying loads which, although modest in amplitude, give rise to microscopic cracks that can ultimately propagate to failure. The fatigue life of a component is primarily dependent on the stress amplitude response at critical failure locations. For most vibration tests, it is common to assume a Gaussian distribution of both the input acceleration and stress response. In real life, however, it is common to experience non-Gaussian acceleration input, and this can cause the response to be non-Gaussian. Examples of non-Gaussian loads include road irregularities such as potholes in the automotive world or turbulent boundary layer pressure fluctuations for the aerospace sector or more generally wind, wave or high amplitude acoustic loads. The paper first reviews some of the methods used to generate non-Gaussian excitation signals with a given power spectral density and kurtosis. The kurtosis of the response is examined once the signal is passed through a linear time invariant system. Finally an algorithm is presented that determines the output kurtosis based upon the input kurtosis, the input power spectral density and the frequency response function of the system. The algorithm is validated using numerical simulations. Direct applications of these results include improved fatigue life estimations and a method to accelerate shaker tests by generating high kurtosis, non-Gaussian drive signals.

  15. Effects of tibial slope changes in the stability of fixed bearing medial unicompartmental arthroplasty in anterior cruciate ligament deficient knees.

    Suero, Eduardo M; Citak, Musa; Cross, Michael B; Bosscher, Marianne R F; Ranawat, Anil S; Pearle, Andrew D

    2012-08-01

    Patients with anterior cruciate ligament (ACL) deficiency may have increased failure rates with UKA as a result of abnormal contact stresses and altered knee kinematics. Variations in the slope of the tibial component in UKA may alter tibiofemoral translation, and affect outcomes. This cadaveric study evaluated tibiofemoral translation during the Lachman and pivot shift tests after changing the slope of a fixed bearing unicondylar tibial component. Sectioning the ACL increased tibiofemoral translation in both the Lachman and pivot shift tests (Pslope leveling (decreasing the posterior slope) of the polyethylene insert in a UKA decreases anteroposterior tibiofemoral translation in the sagittal plane to a magnitude similar to that of the intact knee. With 8° of tibial slope leveling, anterior tibial translation during the Lachman test decreased by approximately 5mm. However, no variation in slope altered the pivot shift kinematics in the ACL deficient knees. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. [Mobility of a polyethylene tibial insert in a mobile total knee prosthesis].

    Castel, E; Roger, B; Camproux, A; Saillant, G

    1999-03-01

    We have studied the mobility of a mobile tibial implant in total knee arthroplasty (TKA) by a radiographical evaluation. We analyzed mobility of the polyethylene tibial insert of 15 "G2S" TKA implanted for one year or more. We established a dynamic radiographical evaluation. We used 3 weight-bearing radiographs: AP in extension and two lateral (one in extension and one at 90 degrees of flexion), two AP with femoral internal and external rotation, 2 strict lateral X-rays in neutral rotation in antero-posterior replacement with a 25 kilograms strength Telos, and 2 AP in varus and valgus with Telos. Wilcoxon's test and Fisher's exact test were used for statistical evaluation. Our study demonstrated preservation of the polyethylene mobility in tibial TKA implant in all movements: in rotation, in antero-posterior translation with Telos, and even in antero-posterior translation during physiological condition with flexion-extension weight-bearing radiographs. Statistical tests were very significant. We noticed that flexion induced anterior translation of tibial polyethylene when PCL was preserved. This study answered to our question whether mobility of TKA tibial implant persists after implantation. This mobility should reduce loosening forces to the tibia and stress in the polyethylene component. Now we have to determine the amplitude of mobility required to reach this objective.

  17. Age variations in the properties of human tibial trabecular bone

    Ding, Ming; Dalstra, M; Danielsen, CC

    1997-01-01

    We tested in compression specimens of human proximal tibial trabecular bone from 31 normal donors aged from 16 to 83 years and determined the mechanical properties, density and mineral and collagen content. Young's modulus and ultimate stress were highest between 40 and 50 years, whereas ultimate...... strain and failure energy showed maxima at younger ages. These age-related variations (except for failure energy) were non-linear. Tissue density and mineral concentration were constant throughout life, whereas apparent density (the amount of bone) varied with ultimate stress. Collagen density (the...... amount of collagen) varied with failure energy. Collagen concentration was maximal at younger ages but varied little with age. Our results suggest that the decrease in mechanical properties of trabecular bone such as Young's modulus and ultimate stress is mainly a consequence of the loss of trabecular...

  18. An accelerated life test model for harmonic drives under a segmental stress history and its parameter optimization

    Zhang Chao

    2015-12-01

    Full Text Available Harmonic drives have various distinctive advantages and are widely used in space drive mechanisms. Accelerated life test (ALT is commonly conducted to shorten test time and reduce associated costs. An appropriate ALT model is needed to predict the lifetime of harmonic drives with ALT data. However, harmonic drives which are used in space usually work under a segmental stress history, and traditional ALT models can hardly be used in this situation. This paper proposes a dedicated ALT model for harmonic drives applied in space systems. A comprehensive ALT model is established and genetic algorithm (GA is adopted to obtain optimal parameters in the model using the Manson fatigue damage rule to describe the fatigue failure process and a cumulative damage method to calculate and accumulate the damage caused by each segment in the stress history. An ALT of harmonic drives was carried out and experimental results show that this model is acceptable and effective.

  19. Accelerated Growth Rate and Increased Drought Stress Resilience of the Model Grass Brachypodium distachyon Colonized by Bacillus subtilis B26.

    François Gagné-Bourque

    Full Text Available Plant growth-promoting bacteria (PGB induce positive effects in plants, for instance, increased growth and reduced abiotic stresses susceptibility. The mechanisms by which these bacteria impact the host plant are numerous, diverse and often specific. Here, we studied the agronomical, molecular and biochemical effects of the endophytic PGB Bacillus subtilis B26 on the full life cycle of Brachypodium distachyon Bd21, an established model species for functional genomics in cereal crops and temperate grasses. Inoculation of Brachypodium with B. subtilis strain B26 increased root and shoot weights, accelerated growth rate and seed yield as compared to control plants. B. subtilis strain B26 efficiently colonized the plant and was recovered from roots, stems and blades as well as seeds of Brachypodium, indicating that the bacterium is able to migrate, spread systemically inside the plant, establish itself in the aerial plant tissues and organs, and is vertically transmitted to seeds. The presence of B. subtilis strain B26 in the seed led to systemic colonization of the next generation of Brachypodium plants. Inoculated Brachypodium seedlings and mature plants exposed to acute and chronic drought stress minimized the phenotypic effect of drought compared to plants not harbouring the bacterium. Protection from the inhibitory effects of drought by the bacterium was linked to upregulation of the drought-response genes, DREB2B-like, DHN3-like and LEA-14-A-like and modulation of the DNA methylation genes, MET1B-like, CMT3-like and DRM2-like, that regulate the process. Additionally, total soluble sugars and starch contents increased in stressed inoculated plants, a biochemical indication of drought tolerance. In conclusion, we show a single inoculation of Brachypodium with a PGB affected the whole growth cycle of the plant, accelerating its growth rates, shortening its vegetative period, and alleviating drought stress effects. These effects are relevant to

  20. Early Adversity, Elevated Stress Physiology, Accelerated Sexual Maturation, and Poor Health in Females

    Belsky, Jay; Ruttle, Paula L.; Boyce, W. Thomas; Armstrong, Jeffrey M.; Essex, Marilyn J.

    2015-01-01

    Evolutionary-minded developmentalists studying predictive-adaptive-response processes linking childhood adversity with accelerated female reproductive development and health scientists investigating the developmental origins of health and disease (DOoHaD) may be tapping the same process, whereby longer-term health costs are traded off for…

  1. Cooling the APS storage ring radio-frequency accelerating cavities: Thermal/stress/fatigue analysis and cavity cooling configuration

    Primdahl, K.; Kustom, R.

    1995-01-01

    The 7-GeV Advanced Photon Source positron storage ring requires sixteen separate 352-MHz radio-frequency (rf) accelerating cavities. Cavities are installed as groups of four, in straight sections used elsewhere for insertion devices. They occupy the first such straight section after injection, along with the last three just before injection. Cooling is provided by a subsystem of the sitewide deionized water system. Pumping equipment is located in a building directly adjacent to the accelerator enclosure. A prototype cavity was fabricated and tested where cooling was via twelve 19-mm-diameter [3/4 in] brazed-on tubes in a series-parallel flow configuration. Unfortunately, the thermal contact to some tubes was poor due to inadequate braze filler. Here, heat transfer studies, including finite-element analysis and test results, of the Advanced Photon Source (APS) storage ring 352-MHz rf accelerating cavities are described. Stress and fatigue life of the copper are discussed. Configuration of water cooling is presented

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

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

    2014-05-01

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

  3. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

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

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

    2013-12-01

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

  5. Photometric and Colorimetric Assessment of LED Chip Scale Packages by Using a Step-Stress Accelerated Degradation Test (SSADT) Method.

    Qian, Cheng; Fan, Jiajie; Fang, Jiayi; Yu, Chaohua; Ren, Yi; Fan, Xuejun; Zhang, Guoqi

    2017-10-16

    By solving the problem of very long test time on reliability qualification for Light-emitting Diode (LED) products, the accelerated degradation test with a thermal overstress at a proper range is regarded as a promising and effective approach. For a comprehensive survey of the application of step-stress accelerated degradation test (SSADT) in LEDs, the thermal, photometric, and colorimetric properties of two types of LED chip scale packages (CSPs), i.e., 4000 °K and 5000 °K samples each of which was driven by two different levels of currents (i.e., 120 mA and 350 mA, respectively), were investigated under an increasing temperature from 55 °C to 150 °C and a systemic study of driving current effect on the SSADT results were also reported in this paper. During SSADT, junction temperatures of the test samples have a positive relationship with their driving currents. However, the temperature-voltage curve, which represents the thermal resistance property of the test samples, does not show significant variance as long as the driving current is no more than the sample's rated current. But when the test sample is tested under an overdrive current, its temperature-voltage curve is observed as obviously shifted to the left when compared to that before SSADT. Similar overdrive current affected the degradation scenario is also found in the attenuation of Spectral Power Distributions (SPDs) of the test samples. As used in the reliability qualification, SSADT provides explicit scenes on color shift and correlated color temperature (CCT) depreciation of the test samples, but not on lumen maintenance depreciation. It is also proved that the varying rates of the color shift and CCT depreciation failures can be effectively accelerated with an increase of the driving current, for instance, from 120 mA to 350 mA. For these reasons, SSADT is considered as a suitable accelerated test method for qualifying these two failure modes of LED CSPs.

  6. [Surgical approaches to tibial plateau fractures].

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

    2018-06-06

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

  7. Association of stressful life events with accelerated bone loss in older men: the Osteoporotic Fractures in Men (MrOS) Study

    Fink, Howard A.; Kuskowski, Michael A.; Cauley, Jane A.; Taylor, Brent C.; Schousboe, John T.; Cawthon, Peggy M.; Ensrud, Kristine E.

    2015-01-01

    Purpose/Introduction Prior studies suggest that stressful life events may increase adverse health outcomes, including falls and possibly fractures. The current study builds on these findings and examines whether stressful life events are associated with increased bone loss. Methods 4388 men aged ≥65 years in the Osteoporotic Fractures in Men study completed total hip bone mineral density (BMD) measures at baseline and visit 2, approximately 4.6 years later, and self-reported stressful life events data mid-way between baseline and visit 2, and at visit 2. We used linear regression to model the association of stressful life events with concurrent annualized total hip BMD loss, and log binomial regression or Poisson regression to model risk of concurrent accelerated BMD loss (>1 SD more than mean annualized change). Results 75.3% of men reported ≥1 type of stressful life event, including 43.3% with ≥2 types of stressful life events. Mean annualized BMD loss was −0.36% (SD 0.88) and 13.9% of men were categorized with accelerated BMD loss (about 5.7% or more total loss). Rate of annualized BMD loss increased with the number of types of stressful life events after adjustment for age (pstressful life events (RR, 1.10 [95% CI, 1.04–1.16]) per increase of 1 type of stressful life event). Fracture risk was not significantly different between stressful life event-accelerated bone loss subgroups (p=0.08). Conclusions In these older men, stressful life events were associated with a small, dose-related increase in risk of concurrent accelerated hip bone loss. Low frequency of fractures limited assessment of whether rapid bone loss mediates any association of stressful life events with incident fractures. Future studies are needed to confirm these findings and to investigate the mechanism that may underlie this association. PMID:25169421

  8. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

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

    1989-01-01

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

  9. Longitudinal tibial epiphyseal bracket in Nievergelt syndrome

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

    1989-04-01

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

  10. Tibial and fibular developmental fields defects

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

    1999-01-01

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

  11. Chronic vitamin C deficiency does not accelerate oxidative stress in ageing brains of guinea pigs

    Tveden-Nyborg, Pernille; Andersen, Stine Hasselholt; Miyashita, Namiyo

    2012-01-01

      Increased oxidative stress in the brain has consistently been implied in ageing and in several degenerative brain disorders. Acting as a pivotal antioxidant in the brain, vitamin C is preferentially retained during deficiency and may play an essential role in neuroprotection during ageing. Thus......, a lack of vitamin C could be associated with an increase in redox imbalance in the ageing brain. The present study compared oxidative stress of ageing to that of a long-term non-scorbutic vitamin C deficiency in guinea pigs. Adults (3-9 months old) were compared to old (36-42 months old) animals during...... a six-month dietary intervention by assessing vitamin C transport and redox homeostasis in the brain. In contrast to our hypothesis, chronic vitamin C deficiency did not affect the measured markers of oxidative stress in the brains of adult and aged animals. However, aged animals generally showed...

  12. Axin1 up-regulated 1 accelerates stress-induced cardiomyocytes apoptosis through activating Wnt/β-catenin signaling.

    Ye, Xing; Lin, Junyi; Lin, Zebin; Xue, Aimin; Li, Liliang; Zhao, Ziqin; Liu, Li; Shen, Yiwen; Cong, Bin

    2017-10-15

    Stress-induced cardiomyocyte apoptosis contributes to the pathogenesis of a variety of cardiovascular diseases, but how stress induces cardiomyocyte apoptosis remains largely unclear. The present study aims to investigate the effects of Axin1 up-regulated 1 (Axud1), a novel pro-apoptotic protein, on the cardiomyocyte survival and the underlying mechanisms. To this end, a rat model under restraint stress (RS) was established and in vitro stress-induced cardiomyocytes culture was achieved. Our data showed that Axud1 was upregulated in the rat myocardia after exposure to RS. Anti-apoptotic Bcl-2 was decreased, whereas pro-apoptotic Bax and Cleaved caspase-3 (Cc3) were increased in a time-dependent manner. The Wnt/β-catenin signaling was observed to be interestingly activated in heart undergoing RS. In addition, the treatment of norepinephrine (NE) to in vitro cardiomyocytes increased Axud1 level and induced cell apoptosis. Wnt/β-catenin signaling was consistently activated. Knockdown of Axud1 using specific siRNA blunted NE-induced cardiomyocytes apoptosis and also inactivated the Wnt/β-catenin signaling. XAV-939, an inhibitor of Wnt/β-catenin signaling, partially reversed the pro-apoptotic effect of NE. In conclusion, Axud1 accelerated stress-induced cardiomyocytes apoptosis through activation of Wnt/β-catenin signaling pathway. Our data provided novel evidence that therapeutic strategies against Axud1 or Wnt/β-catenin signaling might be promising in relation to RS-induced myocardial injury. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Acceleration of vertical migration of corneal epithelial cells in albino rats during chronic immobilization stress

    Timoshin, S.S.; Berezhnova, N.I.

    1986-01-01

    This paper studies the effect of chronic immobilization stress on the kinetics of corneal epithelial cells from the basal layer into higher layers. Experiments were carried out on 49 male rats. The animals were given an intraperitoneal injection of tritium-thymidine and an additional application of 5 microCi of tritium-thymidine was made to its surface because the cornea has no blood supply. The animals were killed and the cornea removed for investigation. Values of the index of labeled nuclei and intensity of thymidine labeling, characterizing DNA synthesis in the corneas of the control and experimental animals showed no significant change compared with their values in a pervious series of experiments. Chronic exposure to stress increased the velocity of vertical migration of the cells from the basal layer toward the outer layers of the cornea

  14. Usefulness of an accelerated transoesophageal stress echocardiography in the preoperative evaluation of high risk severely obese subjects awaiting bariatric surgery

    Tessier Michel

    2010-07-01

    Full Text Available Abstract Background Severe obesity is associated with an increased risk of coronary artery disease (CAD. Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility, safety and utility of transesophageal dobutamine stress echocardiography (TE-DSE using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia. Methods Subjects with severe obesity [body mass index (BMI >40 kg/m2] with known or suspected CAD and being evaluated for bariatric surgery were recruited. Results Twenty subjects (9M/11F, aged 50 ± 8 years (mean ± SD, weighing 141 ± 21 kg and with a BMI of 50 ± 5 kg/m2 were enrolled in the study and underwent a TE-DSE. The accelerated dobutamine infusion protocol used was well tolerated. Eighteen (90% subjects reached their target heart rate with a mean intubation time of 13 ± 4 minutes. Mean dobutamine dose was 31.5 ± 9.9 ug/kg/min while mean atropine dose was 0.5 ± 0.3 mg. TE-DSE was well tolerated by all subjects without complications including no significant arrhythmia, hypotension or reduction in blood arterial saturation. Two subjects had abnormal TE-DSE suggestive of myocardial ischemia. All patients underwent bariatric surgery with no documented cardiovascular complications. Conclusions TE-DSE using an accelerated infusion protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery. Moreover, the absence of myocardial ischemia on TE-DSE correlates well with a low operative risk of cardiac event.

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

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

    2017-12-01

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

  16. TIBIAL LANDMARKS IN ACL ANATOMIC REPAIR

    M. V. Demesсhenko

    2016-01-01

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

  17. A posterior tibial tendon skipping rope

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

    2010-01-01

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

  18. Incidence and epidemiology of tibial shaft fractures

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

    2015-01-01

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

  19. Finite element analysis of intramedullary nailing and double locking plate for treating extra-articular proximal tibial fractures.

    Chen, Fancheng; Huang, Xiaowei; Ya, Yingsun; Ma, Fenfen; Qian, Zhi; Shi, Jifei; Guo, Shuolei; Yu, Baoqing

    2018-01-16

    Proximal tibia fractures are one of the most familiar fractures. Surgical approaches are usually needed for anatomical reduction. However, no single treatment method has been widely established as the standard care. Our present study aims to compare the stress and stability of intramedullary nails (IMN) fixation and double locking plate (DLP) fixation in the treatment of extra-articular proximal tibial fractures. A three-dimensional (3D) finite element model of the extra-articular proximal tibial fracture, whose 2-cm bone gap began 7 cm from the tibial plateau articular surface, was created fixed by different fixation implants. The axial compressive load on an adult knee during single-limb stance was imitated by an axial force of 2500 N with a distribution of 60% to the medial compartment, while the distal end was fixed effectively. The equivalent von Mises stress and displacement of the model was used as the output measures for analysis. The maximal equivalent von Mises stress value of the system in the IMN model was 293.23 MPa, which was higher comparing against that in the DLP fixation model (147.04 MPa). And the mean stress of the model in the IMN model (9.25 MPa) was higher than that of the DLP fixation system in terms of equivalent von Mises stress (EVMS) (P tibial fractures of young patients.

  20. Initial Results of Accelerated Stress Testing on Single-Channel and Multichannel Drivers: Solid-State Lighting Technology Area

    None

    2018-02-28

    This report is the first in a series of studies on accelerated stress testing (AST) of drivers used for SSL luminaires, such as downlights, troffers, and streetlights. A representative group of two-stage commercial driver products was exposed to an AST environment consisting of 75°C and 75% relative humidity (7575). These drivers were a mix of single-channel drivers (i.e., a single output current for one LED primary) and multichannel drivers (i.e., separate output currents for multiple LED primaries). This AST environment was chosen because previous testing on downlights with integrated drivers demonstrated that 38% of the sample population failed in less than 2,500 hours of testing using this method. In addition to AST test results, the performance of an SSL downlight product incorporating an integrated, multichannel driver during extended room temperature operational life (RTOL) testing is also reported. A battery of measurements was used to evaluate these products during accelerated testing, including full electrical characterization (i.e., power consumption, PF, total harmonic distortion [THD], and inrush current) and photometric characterization of external LED loads attached to the drivers (i.e., flicker performance and lumen maintenance).

  1. Tibial shaft fractures in football players

    Daisley Susan

    2007-06-01

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

  2. [Characteristics of the sympathoadrenal system response to psychoemotional stress under hypoxic conditions in aged people with physiological and accelerated aging of the respiratory system].

    Asanov, E O; Os'mak, Ie D; Kuz'mins'ka, L A

    2013-01-01

    The peculiarities of the response of the sympathoadrenal system to psychoemotional and hypoxic stress in healthy young people and in aged people with physiological and accelerated aging of respiratory system were studied. It was shown that in aging a more pronounced response of the sympathoadrenal system to psychoemotional stress. At the same time, elderly people with different types of aging of the respiratory system did not demonstrate a difference in the response of the sympathoadrenal system to psychoemotional stress. Unlike in young people, in aged people, combination of psychoemotional and hypoxic stresses resulted in further activation of the sympathoadrenal system. The reaction of the sympathoadrenal system was more expressed in elderly people with accelerated ageing of the respiratory system.

  3. Photometric and Colorimetric Assessment of LED Chip Scale Packages by Using a Step-Stress Accelerated Degradation Test (SSADT) Method

    Yu, Chaohua; Fan, Xuejun; Zhang, Guoqi

    2017-01-01

    By solving the problem of very long test time on reliability qualification for Light-emitting Diode (LED) products, the accelerated degradation test with a thermal overstress at a proper range is regarded as a promising and effective approach. For a comprehensive survey of the application of step-stress accelerated degradation test (SSADT) in LEDs, the thermal, photometric, and colorimetric properties of two types of LED chip scale packages (CSPs), i.e., 4000 °K and 5000 °K samples each of which was driven by two different levels of currents (i.e., 120 mA and 350 mA, respectively), were investigated under an increasing temperature from 55 °C to 150 °C and a systemic study of driving current effect on the SSADT results were also reported in this paper. During SSADT, junction temperatures of the test samples have a positive relationship with their driving currents. However, the temperature-voltage curve, which represents the thermal resistance property of the test samples, does not show significant variance as long as the driving current is no more than the sample’s rated current. But when the test sample is tested under an overdrive current, its temperature-voltage curve is observed as obviously shifted to the left when compared to that before SSADT. Similar overdrive current affected the degradation scenario is also found in the attenuation of Spectral Power Distributions (SPDs) of the test samples. As used in the reliability qualification, SSADT provides explicit scenes on color shift and correlated color temperature (CCT) depreciation of the test samples, but not on lumen maintenance depreciation. It is also proved that the varying rates of the color shift and CCT depreciation failures can be effectively accelerated with an increase of the driving current, for instance, from 120 mA to 350 mA. For these reasons, SSADT is considered as a suitable accelerated test method for qualifying these two failure modes of LED CSPs. PMID:29035300

  4. Durability and degradation analysis of hydrocarbon ionomer membranes in polymer electrolyte fuel cells accelerated stress evaluation

    Shimizu, Ryo; Tsuji, Junichi; Sato, Nobuyuki; Takano, Jun; Itami, Shunsuke; Kusakabe, Masato; Miyatake, Kenji; Iiyama, Akihiro; Uchida, Makoto

    2017-11-01

    The chemical durabilities of two proton-conducting hydrocarbon polymer electrolyte membranes, sulfonated benzophenone poly(arylene ether ketone) (SPK) semiblock copolymer and sulfonated phenylene poly(arylene ether ketone) (SPP) semiblock copolymer are evaluated under accelerated open circuit voltage (OCV) conditions in a polymer electrolyte fuel cell (PEFC). Post-test characterization of the membrane electrodes assemblies (MEAs) is carried out via gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. These results are compared with those of the initial MEAs. The SPP cell shows the highest OCV at 1000 h, and, in the post-test analysis, the SPP membrane retains up to 80% of the original molecular weight, based on the GPC results, and 90% of the hydrophilic structure, based on the NMR results. The hydrophilic structure of the SPP membrane is more stable after the durability evaluation than that of the SPK. From these results, the SPP membrane, with its simple hydrophilic structure, which does not include ketone groups, is seen to be significantly more resistant to radical attack. This structure leads to high chemical durability and thus impedes the chemical decomposition of the membrane.

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

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

    2013-07-01

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

  6. Newly designed anterolateral and posterolateral locking anatomic plates for lateral tibial plateau fractures: a finite element study.

    Chen, Pengbo; Lu, Hua; Shen, Hao; Wang, Wei; Ni, Binbin; Chen, Jishizhan

    2017-02-23

    Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

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

    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.

  8. Anterior Tibial Artery Pseudoaneurysm: Case Report

    Funda Tor

    2012-06-01

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

  9. Dysplasia epiphysealis hemimelica of the tibial tubercle

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

    2006-03-15

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

  10. Systematic radiographic evaluation of tibial hemimelia with orthopedic implications

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

    2017-04-15

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

  11. Systematic radiographic evaluation of tibial hemimelia with orthopedic implications

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

    2017-01-01

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

  12. Iron overload in a murine model of hereditary hemochromatosis is associated with accelerated progression of osteoarthritis under mechanical stress.

    Camacho, A; Simão, M; Ea, H-K; Cohen-Solal, M; Richette, P; Branco, J; Cancela, M L

    2016-03-01

    Hereditary hemochromatosis (HH) is a disease caused by mutations in the Hfe gene characterised by systemic iron overload and associated with an increased prevalence of osteoarthritis (OA) but the role of iron overload in the development of OA is still undefined. To further understand the molecular mechanisms involved we have used a murine model of HH and studied the progression of experimental OA under mechanical stress. OA was surgically induced in the knee joints of 10-week-old C57BL6 (wild-type) mice and Hfe-KO mice. OA progression was assessed using histology, micro CT, gene expression and immunohistochemistry at 8 weeks after surgery. Hfe-KO mice showed a systemic iron overload and an increased iron accumulation in the knee synovial membrane following surgery. The histological OA score was significantly higher in the Hfe-KO mice at 8 weeks after surgery. Micro CT study of the proximal tibia revealed increased subchondral bone volume and increased trabecular thickness. Gene expression and immunohistochemical analysis showed a significant increase in the expression of matrix metallopeptidase 3 (MMP-3) in the joints of Hfe-KO mice compared with control mice at 8 weeks after surgery. HH was associated with an accelerated development of OA in mice. Our findings suggest that synovial iron overload has a definite role in the progression of HH-related OA. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  13. Mid-term results of total knee arthroplasty with a porous tantalum monoblock tibial component.

    Hayakawa, Kazue; Date, Hideki; Tsujimura, Shunzo; Nojiri, Sho; Yamada, Harumoto; Nakagawa, Kenji

    2014-01-01

    The objectives of the present study were to assess the mid-term results of cementless total knee arthroplasty (TKA) with the porous tantalum monoblock tibial component and to examine the time course of bone changes on plain radiographs. The subjects were 32 patients, 29 patients were available for follow-up. We investigated the mid-term results of TKA after a mean follow-up period of 7 years and 8 months. We also examined changes of the bone over time on plain radiographs. The Knee Society Clinical Rating scores showed significant improvement. Bone changes around the tibial component were as follows: new bone formation and longitudinal trabecular thickening in 41.4% (Type A), only longitudinal trabecular thickening in 41.4% (Type B), and no changes in 17.2% (Type C). Type A and B changes were more frequent in patients with osteoarthritis, whereas Type C was only seen in patients with rheumatoid arthritis. Three knees had an initial gap, but this disappeared in all cases, and no new radiolucent lines were detected. Stress shielding was observed in seven knees (21.9%), but there was no implant loosening related to it. When we examined the relationship between the mechanical axis and the locations of the tips of the tibial pegs in patients with or without stress shielding, no significant differences were found. The results of mid-term follow-up have demonstrated favorable bone ingrowth, suggesting that porous tantalum is a promising material for cementless TKA. © 2013.

  14. Vascularized fibular graft in infected tibial bone loss

    C Cheriyan Kovoor

    2011-01-01

    Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

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

    Skand Sinha

    2018-01-01

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

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

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

    1976-04-01

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

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

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

  18. Therapeutical Management of the Tibial Plateau Fractures

    Obada B.

    2016-11-01

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

  19. Brief Treatment of Symptoms of Post-Traumatic Stress Disorder (PTSD) by Use of Accelerated Resolution Therapy (ART(®)).

    Kip, Kevin E; Elk, Carrie A; Sullivan, Kelly L; Kadel, Rajendra; Lengacher, Cecile A; Long, Christopher J; Rosenzweig, Laney; Shuman, Amy; Hernandez, Diego F; Street, Jennifer D; Girling, Sue Ann; Diamond, David M

    2012-06-01

    Post-Traumatic Stress Disorder (PTSD) is a prevalent, disabling anxiety disorder. This prospective cohort study reports on a new exposure-based therapy known as Accelerated Resolution Therapy (ART(®)) that incorporates the use of eye movements administered in a brief treatment period (1-5 one-hour sessions within three weeks). Eighty adults aged 21-60 years with symptoms of PTSD were recruited from the Tampa Bay area. The ART-based psychotherapy was designed to minimize anxiety and body sensations associated with recall of traumatic memories and to replace distressing images with favorable ones. Participants' mean age was 40 years, 77% were female, and 29% were Hispanic. Participants underwent a median of three ART sessions, 66 of 80 (82.5%) completed treatment, and 54 of 66 (81.8%) provided 2-month follow-up data. Mean scores pre- and post-ART and at 2-month follow-up were: PTSD Checklist: 54.5 ± 12.2 vs. 31.2 ± 11.4 vs. 30.0 ± 12.4; Brief Symptom Inventory: 30.8 ± 14.6 vs. 10.1 ± 10.8 vs. 10.1 ± 12.1; Center for Epidemiologic Studies Depression Scale: 29.5 ± 10.9 vs. 11.8 ± 11.1 vs. 13.5 ± 12.1; Trauma Related Growth Inventory-Distress scale: 18.9 ± 4.1 vs. 7.4 ± 5.9 vs. 8.2 ± 5.9 (p ART vs. post-ART and 2-month comparisons). No serious adverse events were reported. ART appears to be a brief, safe, and effective treatment for symptoms of PTSD.

  20. Brief Treatment of Symptoms of Post-Traumatic Stress Disorder (PTSD) by Use of Accelerated Resolution Therapy (ART®)

    Kip, Kevin E.; Elk, Carrie A.; Sullivan, Kelly L.; Kadel, Rajendra; Lengacher, Cecile A.; Long, Christopher J.; Rosenzweig, Laney; Shuman, Amy; Hernandez, Diego F.; Street, Jennifer D.; Girling, Sue Ann; Diamond, David M.

    2012-01-01

    Post-Traumatic Stress Disorder (PTSD) is a prevalent, disabling anxiety disorder. This prospective cohort study reports on a new exposure-based therapy known as Accelerated Resolution Therapy (ART®) that incorporates the use of eye movements administered in a brief treatment period (1–5 one-hour sessions within three weeks). Eighty adults aged 21–60 years with symptoms of PTSD were recruited from the Tampa Bay area. The ART-based psychotherapy was designed to minimize anxiety and body sensations associated with recall of traumatic memories and to replace distressing images with favorable ones. Participants’ mean age was 40 years, 77% were female, and 29% were Hispanic. Participants underwent a median of three ART sessions, 66 of 80 (82.5%) completed treatment, and 54 of 66 (81.8%) provided 2-month follow-up data. Mean scores pre- and post-ART and at 2-month follow-up were: PTSD Checklist: 54.5 ± 12.2 vs. 31.2 ± 11.4 vs. 30.0 ± 12.4; Brief Symptom Inventory: 30.8 ± 14.6 vs. 10.1 ± 10.8 vs. 10.1 ± 12.1; Center for Epidemiologic Studies Depression Scale: 29.5 ± 10.9 vs. 11.8 ± 11.1 vs. 13.5 ± 12.1; Trauma Related Growth Inventory-Distress scale: 18.9 ± 4.1 vs. 7.4 ± 5.9 vs. 8.2 ± 5.9 (p ART vs. post-ART and 2-month comparisons). No serious adverse events were reported. ART appears to be a brief, safe, and effective treatment for symptoms of PTSD. PMID:25379218

  1. Accelerated Resolution Therapy for treatment of pain secondary to symptoms of combat-related posttraumatic stress disorder

    Kevin E. Kip

    2014-05-01

    Full Text Available Background: As many as 70% of veterans with chronic pain treated within the US Veterans Administration (VA system may have posttraumatic stress disorder (PTSD, and conversely, up to 80% of those with PTSD may have pain. We describe pain experienced by US service members and veterans with symptoms of PTSD, and report on the effect of Accelerated Resolution Therapy (ART, a new, brief exposure-based therapy, on acute pain reduction secondary to treatment of symptoms of PTSD. Methods: A randomized controlled trial of ART versus an attention control (AC regimen was conducted among 45 US service members/veterans with symptoms of combat-related PTSD. Participants received a mean of 3.7 sessions of ART. Results: Mean age was 41.0 + 12.4 years and 20% were female. Most veterans (93% reported pain. The majority (78% used descriptive terms indicative of neuropathic pain, with 29% reporting symptoms of a concussion or feeling dazed. Mean pre-/post-change on the Pain Outcomes Questionnaire (POQ was −16.9±16.6 in the ART group versus −0.7±14.2 in the AC group (p=0.0006. Among POQ subscales, treatment effects with ART were reported for pain intensity (effect size = 1.81, p=0.006, pain-related impairment in mobility (effect size = 0.69, p=0.01, and negative affect (effect size = 1.01, p=0.001. Conclusions: Veterans with symptoms of combat-related PTSD have a high prevalence of significant pain, including neuropathic pain. Brief treatment of symptoms of combat-related PTSD among veterans by use of ART appears to acutely reduce concomitant pain.

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

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

    2017-07-01

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

  3. An accelerated stress testing program for determining the reliability sensitivity of silicon solar cells to encapsulation and metallization systems

    Lathrop, J. W.; Davis, C. W.; Royal, E.

    1982-01-01

    The use of accelerated testing methods in a program to determine the reliability attributes of terrestrial silicon solar cells is discussed. Different failure modes are to be expected when cells with and without encapsulation are subjected to accelerated testing and separate test schedules for each are described. Unencapsulated test cells having slight variations in metallization are used to illustrate how accelerated testing can highlight different diffusion related failure mechanisms. The usefulness of accelerated testing when applied to encapsulated cells is illustrated by results showing that moisture related degradation may be many times worse with some forms of encapsulation than with no encapsulation at all.

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

    Song, Qi-Zhi; Li, Tao

    2012-03-01

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

  5. The effect of retained intramedullary nails on tibial bone mineral density.

    Allen, J C; Lindsey, R W; Hipp, J A; Gugala, Z; Rianon, N; LeBlanc, A

    2008-07-01

    Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures. Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions. Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05). The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

  6. Brief Treatment of Co-Occurring Post Traumatic Stress and Depressive Symptoms By Use of Accelerated Resolution Therapy (ART®

    Kevin eKip

    2013-03-01

    Full Text Available This uncontrolled prospective cohort study evaluated the use of Accelerated Resolution Therapy (ART for treatment of comorbid symptoms of post-traumatic stress disorder (PTSD and major depressive disorder (MDD. Twenty-eight adult subjects, mean age of 41 years (79% female, 36% Hispanic, received a mean of 3.7 + 1.1 ART treatment sessions (range 1-5. ART is a new exposure-based psychotherapy that makes use of eye movements. Subjects completed a range of self-report psychological measures before and after treatment with ART including the 17-item PCL-C checklist (symptoms of PTSD and 20-item Center for Epidemiologic Studies Depression Scale (CES-D. For the PCL-C, the pre-ART mean (+ standard deviation was 62.5 (8.8 with mean reductions of -29.6 (12.5, -30.1 (13.1, and -31.4 (14.04 at post-ART, 2-month, and 4-month follow up, respectively (p<0.0001 for comparisons to Pre-ART score. Compared to pre-ART status, this corresponded to standardized effect sizes of 2.37, 2.30, and 3.01, respectively. For the CES-D, the pre-ART mean was 35.1 (8.8 with mean reductions of -20.6 (11.0, -18.1 (11.5, and -15.6 (14.4 at post-ART, 2-month, and 4-month follow up, respectively (p<0.0001 compared to Pre-ART score. This corresponded to standardized effect sizes of 1.88, 1.58, and 1.09, respectively. Strong correlations were observed at 2-month and 4-month follow-up for post-treatment changes in PTSD and depression symptom scores (r=0.79, r=0.76, respectively, p<0.0002. No serious treatment-related adverse effects were reported. In summary, ART appears to be a promising brief, safe, and effective treatment for adults with clinically significant comorbid symptoms of PTSD and depression. Future controlled and mechanistic studies with this emerging therapy are warranted, particularly given its short treatment duration, and in light of current heightened emphasis on health care cost constraints.

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

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

    2013-06-01

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

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

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

    2008-01-01

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

  9. The indications and donor-site morbidity of tibial cortical strut autografts in the management of defects in long bones.

    Lauthe, O; Soubeyrand, M; Babinet, A; Dumaine, V; Anract, P; Biau, D J

    2018-05-01

    Aims The primary aim of this study was to determine the morbidity of a tibial strut autograft and characterize the rate of bony union following its use. Patients and Methods We retrospectively assessed a series of 104 patients from a single centre who were treated with a tibial strut autograft of > 5 cm in length. A total of 30 had a segmental reconstruction with continuity of bone, 27 had a segmental reconstruction without continuity of bone, 29 had an arthrodesis and 18 had a nonunion. Donor-site morbidity was defined as any event that required a modification of the postoperative management. Union was assessed clinically and radiologically at a median of 36 months (IQR, 14 to 74). Results Donor-site morbidity occurred in four patients (4%; 95% confidence interval (CI) 1 to 10). One patient had a stress fracture of the tibia, which healed with a varus deformity, requiring an osteotomy. Two patients required evacuation of a haematoma and one developed anterior compartment syndrome which required fasciotomies. The cumulative probability of union was 90% (95% CI 80 to 96) at five years. The type of reconstruction (p = 0.018), continuity of bone (p = 0.006) and length of tibial graft (p = 0.037) were associated with the time to union. Conclusion The tibial strut autograft has a low risk of morbidity and provides adequate bone stock for treating various defects of long bones. Cite this article: Bone Joint J 2018;100-B:667-74.

  10. Patella height changes post high tibial osteotomy

    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.

  11. Stress

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  12. Bilateral metachronous periosteal tibial amyloid tumors

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

    2000-01-01

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

  13. Computed tomography of tibial plateau fractures

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

    1984-01-01

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

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

    Zelle, Boris A; Boni, Guilherme

    2015-01-01

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

  15. Stress steroids as accelerators of Alzheimer's disease. : Effects of chronically elevated levels of allopregnanolone in transgenic AD models.

    Bengtsson, Sara

    2013-01-01

    Background Alzheimer’s disease (AD) and dementia are devastating con­ditions not only for the affected patients but also for their families.  The economical costs for the society are tremendous. Mid-life psychological stress, psychosocial stress and post-traumatic stress disorder cause cognitive dysfunction and lead to increased risk for dementia. However, the mecha­nisms behind stress-induced AD and dementia are not known. AD is char­acterized by solid amyloid plaques in the CNS. However, ov...

  16. Stability of CIGS Solar Cells and Component Materials Evaluated by a Step-Stress Accelerated Degradation Test Method: Preprint

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15oC and then a 15% relative humidity (RH) increment step, beginning from 40oC/40%RH (T/RH = 40/40) to 85oC/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear 'stepwise' feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH < 55/55 and some showing large Voc, FF, and efficiency degradation due to increased series Rs (ohm-cm2) at T/RH ≥ 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and 'capacitor quality' factor (CPE-P), which were related to the cells? p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH ≥ 70/70. At T/RH = 85/70, substantial blistering of

  17. Catalyst Degradation Under Potential Cycling as an Accelerated Stress Test for PBI-Based High-Temperature PEM Fuel Cells - Effect of Humidification

    Søndergaard, Tonny; Cleemann, Lars Nilausen; Zhong, Lijie

    2018-01-01

    In the present work, high-temperature polymer electrolyte membrane fuel cells were subjected to accelerated stress tests of 30,000 potential cycles between 0.6 and 1.0 V at 160 textdegreeC (133 h cycling time). The effect that humidity has on the catalyst durability was studied by testing either...... with or without humidification of the nitrogen that was used as cathode gas during cycling segments. Pronounced degradation was seen from the polarization curves in both cases, though permanent only in the humidified case. In the unhumidified case, the performance loss was more or less recoverable following 24 h...

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

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

    1990-01-01

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

  19. Physeal growth arrest after tibial lengthening in achondroplasia

    2012-01-01

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

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

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

    2017-01-01

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

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

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

    2017-11-01

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

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

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

    2015-01-01

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

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

    Gwinner, Clemens

    2016-01-01

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

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

    Jirman, R; Vavrík, P; Horák, Z

    2009-02-01

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

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

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

    2008-07-01

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

  6. Melatonin Improves the Photosynthetic Apparatus in Pea Leaves Stressed by Paraquat via Chlorophyll Breakdown Regulation and Its Accelerated de novo Synthesis

    Katarzyna Szafrańska

    2017-05-01

    Full Text Available The positive effect of melatonin on the function of the photosynthetic apparatus is known, but little is known about the specific mechanisms of melatonin's action in plants. The influence of melatonin on chlorophyll metabolism of 24-day-old Pisum sativum L. seedlings during paraquat (PQ-induced oxidative stress was investigated in this study. Seeds were hydro-primed with water (H, 50 and 200 μM melatonin/water solutions (H-MEL50, H-MEL200, while non-primed seeds were used as controls (C. Increases in chlorophyllase activity (key enzyme in chlorophyll degradation and 5-aminolevulinic acid contents (the first compound in the porphyrin synthesis pathway were observed in H-MEL50 and H-MEL200 leaf disks. This suggests that melatonin may accelerate damaged chlorophyll breakdown and its de novo synthesis during the first hours of PQ treatment. Elevated level of pheophytin in control leaf disks following 24 h of PQ incubation probably was associated with an enhanced rate of chlorophyll degradation through formation of pheophytin as a chlorophyll derivative. This validates the hypothesis that chlorophyllide, considered for many years, as a first intermediate of chlorophyll breakdown is not. This is indicated by the almost unchanged chlorophyll to chlorophyllide ratio after 24 h of PQ treatment. However, prolonged effects of PQ-induced stress (48 h revealed extensive discolouration of control and water-treated leaf disks, while melatonin treatment alleviated PQ-induced photobleaching. Also the ratio of chlorophyll to chlorophyllide and porphyrin contents were significantly higher in plants treated with melatonin, which may indicate that this indoleamine both retards chlorophyll breakdown and stimulates its de novo synthesis during extended stress. We concluded that melatonin added into the seeds enhances the ability of pea seedlings to accelerate chlorophyll breakdown and its de novo synthesis before stress appeared and for several hours after, while

  7. FERTILITY INTENTIONS AND EARLY LIFE HEALTH STRESS AMONG WOMEN IN EIGHT INDIAN CITIES: TESTING THE REPRODUCTIVE ACCELERATION HYPOTHESIS.

    Kulathinal, Sangita; Säävälä, Minna

    2015-09-01

    In life history theory, early life adversity is associated with an accelerated reproductive tempo. In harsh and unpredictable conditions in developing societies fertility is generally higher and the reproductive tempo faster than in more secure environments. This paper examines whether differences in female anthropometry, particularly adult height, are associated with fertility intentions of women in urban environments in India. The study population consists of women aged 15-29 (N=4485) in slums and non-slums of eight Indian cities in the National Family Health Survey (NFHS) of 2005-2006. Adult height is taken as a proxy for early childhood health and nutritional condition. Fertility intentions are examined by using two variables: the desire to have a child or another child, and to have it relatively soon, as indicative of accelerated reproductive scheduling. Evidence supporting the acceleration hypothesis is found in two urban frames out of 26 examined in a two-staged multinomial logistic model. In three cases, the relationship between fertility intentions and height is the opposite than expected by the acceleration hypothesis: taller women have a higher predictive probability of desiring a(nother) child and/or narrower birth spacing. Potential explanations for the partly contradictory relationship between the childhood health indicator and fertility intentions are discussed.

  8. Maxwell-Faraday Stresses in Electromagnetic Fields and the Self-Force on a Uniformly Accelerating Point Charge

    Rowland, D. R.

    2007-01-01

    The physical analysis of a uniformly accelerating point charge provides a rich problem to explore in advanced courses in electrodynamics and relativity since it brings together fundamental concepts in relation to electromagnetic radiation, Einstein's equivalence principle and the inertial mass of field energy in ways that reveal subtleties in each…

  9. Biomechanical Factors in the Etiology of Tibial Stress Fractures

    2006-08-01

    Science in Sports and Exercise. 22:2, S69, April, 1990. Ebbeling, C. J., Hamill, J., Freedson, P. S., Rowland, T. W. Metabolic and mechanical...Ratcliffe, R., Thompson, S., Hamill, J. Stability and the metabolic cost of human walking. XIth International Symposium on Posture and Gait: Control...l2,000, 9/1982 - 6/1984. 2. Ergonomics of lower extremity function, KangaROOS , USA, $58,000, 9/1986 - 9/1989. 3. Prophylactic Knee and Ankle

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

    South African Journal of Sports Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 25, No 3 (2013) >. Log in or Register to get access to full text downloads.

  11. Limited open reduction is better for simple- distal tibial shaft fractures than minimally invasive plate osteosynthesis.

    Li, Q; Zeng, B F; Luo, C F; Song, S; Zhang, C Q; Kong, W Q

    2014-07-24

    The aim of this study was to compare the effects and indications of minimally invasive plate osteosynthesis (MIPO) and limited open reduction (LOR) for managing distal tibial shaft fractures. A total of 79 cases of distal tibial shaft fractures were treated surgically in our trauma center. The 79 fracture cases were classified into type A, B, and C (C1) according to the Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, with 28, 32, and 19 cases, respectively. Among the 79 fracture cases, 52 were closed fractures and 27 were open fractures (GUSTILO, I-II). After adequate preparation, 48 cases were treated with LOR and 31 cases were treated with MIPO. All cases were followed up for 12 to 18 months, with an average of 16.4 months. During the follow-up period, 76 fracture cases were healed in the first stage, whereas the 3 cases that developed non-union were treated by changing the fixation device and autografting. For types A, B, and some of C simple fractures (C1), LOR accelerated the fracture healing and lowered the non-union rate. One case suffered from regional soft tissue infection, which was controlled by wound dressing and intravenous antibiotics. Another case that developed local skin necrosis underwent local flap transplant. LOR promoted bone healing and lowered the non-union rate of several simple-distal tibial shaft fractures. Thereafter, the incidence of soft tissue complication was not significantly increased. However, for complex and comminuted fractures, MIPO was the preferred method for correcting bone alignment and protecting soft tissue, leading to functional recovery.

  12. Posterior Cruciate Ligament Tibial Avulsion treated with Open Reduction and Internal Fixation through the Burks and Schaffer Approach

    Khatri K

    2015-07-01

    Full Text Available Objective: To report functional outcome in Posterior Cruciate Ligament (PCL tibial avulsion fractures treated with open reduction and internal fixation through Burks and Schaffer approach. The patient specific functional outcome measures like IKDC grading together with objective grading with stress radiographs have rarely been used to assess PCL tibial avulsion fractures. Material and Methods: Twenty seven patients (21 males and 6 females were included in the study. The mean follow up duration was 22.30±6.82 months. They were assessed using international knee documentation committee (IKDC grades, Lysholm scoring and stress radiography. The injury severity scores (ISS of the patients were also recorded. Results: The mean Lysholm scores at the time of last follow up was 90.85±5.58. The IKDC grades achieved were normal in 20 patients, near normal in five and abnormal in two. The PCL laxity determined on active hamstring contraction stress radiography was grade I in 20 cases and grade II in seven cases. All patients had achieved bony union of tibial avulsion fractures at the time of last follow up. Statistically significant association was found between higher ISS and lower Lysholm scores. (t=3.455, p=0.0019. Good IKDC grades were associated with higher Lysholm scores (analysis of variance, F=32.51, p<.0001.There was no correlation between PCL laxity and functional outcome (t=.857, p =0.399. Conclusion: PCL tibial avulsion fractures treated through Burk and Schaffer approach with open reduction and internal fixation produces good results. The early rehabilitation without cast immobilisation prevents arthrofibrosis.

  13. Influence of Bone Remodeling Inhibition on the Development of Experimental Stress Fractures

    Schaffler, Mitchell B

    2005-01-01

    .... Using a bisphosphonate (BIS) to suppress remodeling in the rabbit tibial stress fracture model, we found that antiresorptive therapy reduced the intensity of the stress fracture response in this model...

  14. Oxidative stress and age-related changes in T cells: is thalassemia a model of accelerated immune system aging?

    Ghatreh-Samani, Mahdi; Esmaeili, Nafiseh; Soleimani, Masoud; Asadi-Samani, Majid; Ghatreh-Samani, Keihan; Shirzad, Hedayatolah

    2016-01-01

    Iron overload in β-thalassemia major occurs mainly due to blood transfusion, an essential treatment for β-thalassemia major patients, which results in oxidative stress. It has been thought that oxidative stress causes elevation of immune system senescent cells. Under this condition, cells normally enhance in aging, which is referred to as premature immunosenescence. Because there is no animal model for immunosenescence, most knowledge on the immunosenescence pattern is based on induction of immunosenescence. In this review, we describe iron overload and oxidative stress in β-thalassemia major patients and how they make these patients a suitable human model for immunosenescence. We also consider oxidative stress in some kinds of chronic virus infections, which induce changes in the immune system similar to β-thalassemia major. In conclusion, a therapeutic approach used to improve the immune system in such chronic virus diseases, may change the immunosenescence state and make life conditions better for β-thalassemia major patients.

  15. Nondestructive Evaluation and Monitoring Results from COPV Accelerated Stress Rupture Testing, NASA White Sands Test Facility (WSTF)

    Saulsberry Regor

    2010-01-01

    Develop and demonstrate NDE techniques for real-time characterization of CPVs and, where possible, identification of NDE capable of assessing stress rupture related strength degradation and/or making vessel life predictions (structural health monitoring or periodic inspection modes). Secondary: Provide the COPV user and materials community with quality carbon/epoxy (C/Ep) COPV stress rupture progression rate data. Aid in modeling, manufacturing, and application of COPVs for NASA spacecraft.

  16. Proposed research on class I components to test a general approach to accelerated aging under combined stress environments

    Gillen, K.T.; Salazar, E.A.; Frank, C.W.

    1977-04-01

    This report summarizes research on the aging of Class I components in environments representative of nuclear power plants. It discusses Class IE equipment used in nuclear power plants, typical environments encountered by Class IE components, and aging techniques used to qualify this equipment. General discussions of radiation chemistry of polymers and accelerated aging techniques are also included. Based on the inadequacies of present aging techniques for Class IE equipment, a proposal for an experimental program on electrical cables is presented. One of the main purposes of the proposed work is to obtain relevant data in two areas of particular concern--the effect of radiation dose rate on polymer degradation, and the importance of synergism for combined thermal and radiation environments. A new model that allows combined environment accelerated aging to be carried out is introduced, and it is shown how the experimental data to be generated can be used to test this model

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

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

    2017-08-01

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

  18. An unusual stress fracture: Bilateral posterior longitudinal stress fracture of tibia.

    Malkoc, Melih; Korkmaz, Ozgur; Ormeci, Tugrul; Oltulu, Ismail; Isyar, Mehmet; Mahirogulları, Mahir

    2014-01-01

    Stress fractures (SF) occur when healthy bone is subjected to cyclic loading, which the normal carrying range capacity is exceeded. Usually, stress fractures occur at the metatarsal bones, calcaneus, proximal or distal tibia and tends to be unilateral. This article presents a 58-year-old male patient with bilateral posterior longitudinal tibial stress fractures. A 58 years old male suffering for persistent left calf pain and decreased walking distance for last one month and after imaging studies posterior longitudinal tibial stress fracture was detected on his left tibia. After six months the patient was admitted to our clinic with the same type of complaints in his right leg. All imaging modalities and blood counts were performed and as a result longitudinal posterior tibial stress fractures were detected on his right tibia. Treatment of tibial stress fracture includes rest and modified activity, followed by a graded return to activity commensurate with bony healing. We have applied the same treatment protocol and our results were acceptable but our follow up time short for this reason our study is restricted for separate stress fractures of the posterior tibia. Although the main localization of tibial stress fractures were unilateral, anterior and transverse pattern, rarely, like in our case, the unusual bilateral posterior localization and longitudinal pattern can be seen. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

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

    2014-09-01

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

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

    E. Revelo Jiron

    2009-12-01

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

  1. The Protective Effect of Antarctic Krill Oil on Cognitive Function by Inhibiting Oxidative Stress in the Brain of Senescence-Accelerated Prone Mouse Strain 8 (SAMP8) Mice.

    Li, Qian; Wu, Fengjuan; Wen, Min; Yanagita, Teruyoshi; Xue, Changhu; Zhang, Tiantian; Wang, Yuming

    2018-02-01

    Alzheimer's disease (AD) is a common neurodegenerative disorder, and oxidative stress plays a vital role in its progression. Antarctic krill oil (AKO) is rich in polyunsaturated fatty acids, which has various biological activities, such as improving insulin sensitivity, alleviating inflammation and ameliorating oxidative stress. In this study, the protective effect of AKO against AD were investigated in senescence-accelerated prone mouse strain 8 (SAMP8) mice. Results showed that treatment with AKO could effectively ameliorate learning and memory deficits and ease the anxiety in SAMP8 mice by Morris water maze, Barnes maze test and open-field test. Further analysis indicated that AKO might reduce β-amyloid (Aβ) accumulation in hippocampus through decreasing the contents of malondialdehyde (MDA) and 7,8-dihydro-8-oxoguanine (8-oxo-G), increasing the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the brain of SAMP8 mice. The results of Morris water maze, Barnes maze test and open-field test indicated that Antarctic krill oil (AKO) improved the cognitive function and anxiety of SAMP8 mice. AKO reduced the Aβ 42 level in hippocampus of SAMP8 mice. AKO ameliorated oxidative stress in brain rather than in serum and liver of SAMP8 mice. © 2018 Institute of Food Technologists®.

  2. External fixation using locking plate in distal tibial fracture: a finite element analysis.

    Zhang, Jingwei; Ebraheim, Nabil; Li, Ming; He, Xianfeng; Schwind, Joshua; Liu, Jiayong; Zhu, Limei

    2015-08-01

    External fixation of tibial fractures using a locking plate has been reported with favorable results in some selected patients. However, the stability of external plate fixation in this fracture pattern has not been previously demonstrated. We investigated the stability of external plate fixation with different plate-bone distances. In this study, the computational processing model of external fixation of a distal tibial metaphyseal fracture utilizing the contralateral femoral less invasive stabilization system plate was analyzed. The plate was placed on the anteromedial aspect of tibia with different plate-bone distances: 1, 10, 20, and 30 mm. Under axial load, the stiffness of construct in all groups was higher than intact tibia. Under axial load with an internal rotational force, the stiffness of construct with 1 and 10 mm plate-bone distances was similar to that of an intact tibia and the stiffness of the construct with 20 and 30 mm distances was lower than that of an intact tibia. Under axial load with an external rotational force, the stiffness of the construct in all groups was lower than that of an intact tibia. The maximum plate stresses were concentrated at the two most distal screws and were highest in the construct with the 10 mm plate-bone distance, and least in the construct with a 1 mm plate-bone distance. To guarantee a stable external plate fixation in distal tibial fracture, the plate-bone distance should be less than 30 mm.

  3. Evaluation of Fibular Fracture Type vs Location of Tibial Fixation of Pilon Fractures.

    Busel, Gennadiy A; Watson, J Tracy; Israel, Heidi

    2017-06-01

    Comminuted fibular fractures can occur with pilon fractures as a result of valgus stress. Transverse fibular fractures can occur with varus deformation. No definitive guide for determining the proper location of tibial fixation exists. The purpose of this study was to identify optimal plate location for fixation of pilon fractures based on the orientation of the fibular fracture. One hundred two patients with 103 pilon fractures were identified who were definitively treated at our institution from 2004 to 2013. Pilon fractures were classified using the AO/OTA classification and included 43-A through 43-C fractures. Inclusion criteria were age of at least 18 years, associated fibular fracture, and definitive tibial plating. Patients were grouped based on the fibular component fracture type (comminuted vs transverse), and the location of plate fixation (medial vs lateral) was noted. Radiographic outcomes were assessed for mechanical failures. Forty fractures were a result of varus force as evidenced by transverse fracture of the fibula and 63 were due to valgus force with a comminuted fibula. For the transverse fibula group, 14.3% mechanical complications were noted for medially placed plate vs 80% for lateral plating ( P = .006). For the comminuted fibular group, 36.4% of medially placed plates demonstrated mechanical complications vs 16.7% for laterally based plates ( P = .156). Time to weight bearing as tolerated was also noted to be significant between groups plated medially and laterally for the comminuted group ( P = .013). Correctly assessing the fibular component for pilon fractures provides valuable information regarding deforming forces. To limit mechanical complications, tibial plates should be applied in such a way as to resist the original deforming forces. Level of Evidence Level III, comparative study.

  4. Accelerated testing of space batteries

    Mccallum, J.; Thomas, R. E.; Waite, J. H.

    1973-01-01

    An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.

  5. Study of Black Cumin (Nigella sativa L. Germination Attributes and Seed Vigur under Salinity Stress by Osmopriming Accelerators Pretreatment

    K Fathi Amirkhiz

    2012-10-01

    Full Text Available Soil and water salinity in arid and semi-arid regions, is one of the most important stresses, can severely limit crop production. Black Cumin (Nigella sativa L. is annual important herbal plant in Rununculaceae Family that sense to salinity. This study was conducted to evaluate the effects of the Priming on seed germination of Black Cumin under saline stress. The experiment was carried out as factorial based on completely randomized design (CRD with three replications. The experimental factors were salinity stress including: (0, 62.2, 124.2, 186.2 and 248.8 mM and three levels of priming, seed primed with Kno3 (0.2 %, for the period of 72 hours, GA (500 ppm, during 48 hours and hydro priming (water distiller, during 24 hours. A saline stress level treated by applies of NaCl, and for priming of distiller water use hydropriming technique. At the first stage, Black Cumin seed was treat and dried at 25°C, then subjected to saline stress treatments for two week at room temperature. The results showed that priming technique had a significant effect (p≤0.01 on seedling parameters. Among pretreatment, The Kno3 had the most positive effect on germination coefficient (GC and thus GA had the most positive effect on mean germination time (MGT. In order hand, these seeds at the minimum time had the most germination rate. Means comparing showed that the most and least rate of germination was obtained by KNO3 and Hydro priming respectively. So under different level of saline stress, pretreatments of KNO3 and hydro priming had useful effect on radical length, more lateral roots and higher proportion of root to plumule, and the most root and plumule fresh weight was obtain by hydro priming pretreatments. So pretreatment of 500 ppm GA reduced number of abnormal seedlings.The simple correlation coefficients showed that radical length with mean germination time (MGT had significantly negative coefficient (R2=-0.726**, with abnormal seedlings number had no

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

    Al-Ashhab, Mohamed E

    2017-03-01

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

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

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

  8. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    2010-04-01

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

  9. Stress

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  10. Bayes Analysis and Reliability Implications of Stress-Rupture Testing a Kevlar/Epoxy COPV Using Temperature and Pressure Acceleration

    Phoenix, S. Leigh; Kezirian, Michael T.; Murthy, Pappu L. N.

    2009-01-01

    Composite Overwrapped Pressure Vessels (COPVs) that have survived a long service time under pressure generally must be recertified before service is extended. Flight certification is dependent on the reliability analysis to quantify the risk of stress rupture failure in existing flight vessels. Full certification of this reliability model would require a statistically significant number of lifetime tests to be performed and is impractical given the cost and limited flight hardware for certification testing purposes. One approach to confirm the reliability model is to perform a stress rupture test on a flight COPV. Currently, testing of such a Kevlar49 (Dupont)/epoxy COPV is nearing completion. The present paper focuses on a Bayesian statistical approach to analyze the possible failure time results of this test and to assess the implications in choosing between possible model parameter values that in the past have had significant uncertainty. The key uncertain parameters in this case are the actual fiber stress ratio at operating pressure, and the Weibull shape parameter for lifetime; the former has been uncertain due to ambiguities in interpreting the original and a duplicate burst test. The latter has been uncertain due to major differences between COPVs in the database and the actual COPVs in service. Any information obtained that clarifies and eliminates uncertainty in these parameters will have a major effect on the predicted reliability of the service COPVs going forward. The key result is that the longer the vessel survives, the more likely the more optimistic stress ratio model is correct. At the time of writing, the resulting effect on predicted future reliability is dramatic, increasing it by about one "nine," that is, reducing the predicted probability of failure by an order of magnitude. However, testing one vessel does not change the uncertainty on the Weibull shape parameter for lifetime since testing several vessels would be necessary.

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

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

    1998-12-01

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

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

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

    1999-01-01

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

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

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

    1998-01-01

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

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

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

    2000-01-01

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

  15. Tibial and fibular angles in homozygous sickle cell disease

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

    1986-01-01

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

  16. Distal tibial fractures are a poorly recognised complication with fibula free flaps.

    Durst, A; Clibbon, J; Davis, B

    2015-09-01

    The fibula free flap is ideal for complex jaw reconstructions, with low reported donor and flap morbidity. We discuss a distal tibial stress fracture two months following a vascularised fibula free flap procedure. Despite being an unrecognised complication, a literature review produced 13 previous cases; only two were reported in the reconstructive surgery literature, with the most recent claiming to be the first. The majority of these studies treated this fracture non-operatively; none reported their patient follow-up. Each case presented with ipsilateral leg pain, which has been cited as an early donor site morbidity in as many as 40% of fibula free flap cases. It is known that the fibula absorbs at least 15% of leg load on weight bearing. Studies have shown severe valgus deformities in up to 25% of patients with fibulectomies. We treated our patient operatively, first correcting his worsening valgus deformity with an external fixator, then reinforcing his healed fracture with a long distal tibial plate. We believe that this complication is underreported, unexpected and not mentioned during the consenting process. By highlighting the management of our case and the literature, we aim to increase awareness (and thus further reporting and appropriate management) of this debilitating complication.

  17. [Balloon osteoplasty as reduction technique in the treatment of tibial head fractures].

    Freude, T; Kraus, T M; Sandmann, G H

    2015-10-01

    Tibial plateau fractures requiring surgery are severe injuries of the lower extremities. Depending on the fracture pattern, the age of the patient, the range of activity and the bone quality there is a broad variation in adequate treatment.  This article reports on an innovative treatment concept to address split depression fractures (Schatzker type II) and depression fractures (Schatzker type III) of the tibial head using the balloon osteoplasty technique for fracture reduction. Using the balloon technique achieves a precise and safe fracture reduction. This internal osteoplasty combines a minimal invasive percutaneous approach with a gently rise of the depressed area and the associated protection of the stratum regenerativum below the articular cartilage surface. This article lights up the surgical procedure using the balloon technique in tibia depression fractures. Using the balloon technique a precise and safe fracture reduction can be achieved. This internal osteoplasty combines a minimally invasive percutaneous approach with a gentle raising of the depressed area and the associated protection of the regenerative layer below the articular cartilage surface. Fracture reduction by use of a tamper results in high peak forces over small areas, whereas by using the balloon the forces are distributed over a larger area causing less secondary stress to the cartilage tissue. This less invasive approach might help to achieve a better long-term outcome with decreased secondary osteoarthritis due to the precise and chondroprotective reduction technique.

  18. MRI in diagnostic of soft tissue damages by fractures of lateral tibial plate

    Dimitrova, D.; Proichev, V.; Popov, I.

    2015-01-01

    Full text: The knee is one of the most often injured joint. Fractures of tibial condyles are the most common articular damages. Koton and Berg call them „bumper“ fractures the tibia plateau is vulnerable to both high- and low-energy injury mechanisms due to its vulnerable position in the lower extremity. It must bear significant weight and sustain significant impact and deceleration forces with little skeletal constraint, and has scant surrounding soft tissue and a tethered medial and lateral integument. Furthermore, the tibial plateau has relatively forgiving ligamentous attachments that must allow for a large range of motion in a single plane. Not surprisingly, given the diversity of injury, management of these fractures has come to include a wide variety of treatment strategies. traditionally, ligament injury associated with plateau fractures has been diagnosed indirectly with stress radiographs and physical examination. With increasing use of more sensitive MRI and arthroscopy, associated ligament and meniscus injuries have been found in significant percentages of plateau fractures. these soft tissue injuries consist primarily of MCL lesions, meniscal injuries, and ACL disruptions. However, studies addressing associated soft tissue injuries all agree that neither the type of plateau fracture nor the presence or absence of ligament injury correlates with the incidence of meniscal tears

  19. Cathinone, an active principle of Catha edulis, accelerates oxidative stress in the limbic area of swiss albino mice.

    Safhi, Mohammed M; Alam, Mohammad Firoz; Hussain, Sohail; Hakeem Siddiqui, Mohammed Abdul; Khuwaja, Gulrana; Jubran Khardali, Ibrahim Abdu; Al-Sanosi, Rashad Mohammed; Islam, Fakhrul

    2014-10-28

    Cathinone hydrochloride is an active principle of the khat plant (Catha edulis) that produces pleasurable and stimulating effects in khat chewers. To the best of our knowledge no data of cathinone on oxidative stress in limbic areas of mice is available. This is the first study of cathinone on oxidative stress in limbic areas of the brain in Swiss albino male mice. The animals were divided into four groups. Group-I was the control group and received vehicle, while groups-II to IV received (-)-cathinone hydrochloride (0.125, 0.25 and 0.5 mg/kg body wt., i.p.) once daily for 15 days. The level of lipid peroxidation (LPO) was elevated dose-dependently and was significant (p<0.05, p<0.01) with doses of 0.25 and 0.5mg/kg body wt. of cathinone as compared to control group. In contrast, the content of reduced glutathione (GSH) was decreased significantly (p<0.01, p<0.001) with doses of 0.25 and 0.5mg/kg body wt. of cathinone as compared to control group. The activity of antioxidant enzymes (GPx, GR, GST, CAT, and SOD) was also decreased dose-dependently: the decreased activity of GPx, GR, catalase and SOD was significant with doses of 0.25 and 0.5 mg of cathinone as compared to control group, while the activity of GST was decreased dose-dependently and was significant with 0.5mg of cathinone as compared to control group. The results indicate that the cathinone generated oxidative stress hampered antioxidant enzymes, glutathione and lipid peroxidation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Overexpression of AtGRDP2, a novel glycine-rich domain protein, accelerates plant growth and improves stress tolerance

    Maria Azucena Ortega-Amaro

    2015-01-01

    Full Text Available Proteins with glycine-rich signatures have been reported in a wide variety of organisms including plants, mammalians, fungi, and bacteria. Plant glycine-rich protein genes exhibit developmental and tissue-specific expression patterns. Herein, we present the characterization of the AtGRDP2 gene using Arabidopsis null and knockdown mutants and, Arabidopsis and lettuce over-expression lines. AtGRDP2 encodes a short glycine-rich domain protein, containing a DUF1399 domain and a putative RNA recognition motif. AtGRDP2 transcript is mainly expressed in Arabidopsis floral organs, and its deregulation in Arabidopsis Atgrdp2 mutants and 35S::AtGRDP2 over-expression lines produces alterations in development. The 35S::AtGRDP2 over-expression lines grow faster than the WT, while the Atgrdp2 mutants have a delay in growth and development. The over-expression lines accumulate higher levels of indole-3-acetic acid and, have alterations in the expression pattern of ARF6, ARF8 and miR167 regulators of floral development and auxin signaling. Under salt stress conditions, 35S::AtGRDP2 over-expression lines displayed higher tolerance and increased expression of stress marker genes. Likewise, transgenic lettuce plants over-expressing the AtGRDP2 gene manifest increased growth rate and early flowering time. Our data reveal an important role for AtGRDP2 in Arabidopsis development and stress response, and suggest a connection between AtGRDP2 and auxin signaling.

  1. Effect of different surgical methods on traumatic response degree and osteoblast-osteoclast balance in patients with distal tibial fracture

    Yun-Qiang Fan

    2017-01-01

    Full Text Available Objective: To study the effect of different surgical methods on trauma response degree and osteoblast-osteoclast balance in patients with distal tibial fracture. Methods: 58 cases of patients with distal tibial fracture who received open reduction and internal fixation in Orthopedics Department of our hospital from May 2013 to October 2015 were selected as research subjects and divided into delayed group (n = 29 and routine group (n = 29 according to different timing of surgery. Delayed group received open reduction and internal fixation 7–15 d after trauma and routine group received open reduction and internal fixation within 24 h after trauma. Levels of serum stress response indicators and osteoblast-osteoclast markers were compared between two groups. Results: On the day after operation, serum adrenocorticotropic hormone, cortisol, renin, angiotensin II, epinephrine and norepinephrine levels of delayed group were significantly lower than those of control group (P<0.05; on the 7th day after operation, serum osteocalcin, procollagen type I carboxyl-terminal peptide and bone alkaline phosphatase of delayed group were significantly higher than those of control group (P<0.05 while cross-linked carboxyl-terminal telopeptide of type I collagen and tartrate-resistant acid phosphatase isoform 5b levels were significantly lower than those of control group (P<0.05. Conclusions: Delayed open reduction and internal fixation treatment of distal tibial fracture can reduce the trauma caused by surgical procedures, increase osteoblast viability and inhibit osteoclast viability, which are conducive to fracture healing.

  2. Antinociceptive and antiallodynic effects of Momordica charantia L. in tibial and sural nerve transection-induced neuropathic pain in rats.

    Jain, Vivek; Pareek, Ashutosh; Paliwal, Nishant; Ratan, Yashumati; Jaggi, Amteshwar Singh; Singh, Nirmal

    2014-02-01

    This study was designed to investigate the ameliorative potential of Momordica charantia L. (MC) in tibial and sural nerve transection (TST)-induced neuropathic pain in rats. TST was performed by sectioning tibial and sural nerve portions (2 mm) of the sciatic nerve, and leaving the common peroneal nerve intact. Acetone drop, pin-prick, hot plate, paint-brush, and walking track tests were performed to assess cold allodynia, mechanical and heat hyperalgesia, and dynamic mechanical allodynia and tibial functional index, respectively. The levels of tumour necrosis factor (TNF)-alpha and thio-barbituric acid reactive substances (TBARS) were measured in the sciatic nerve as an index of inflammation and oxidative stress. MC (all doses, orally, once daily) was administered to the rats for 24 consecutive days. TST led to significant development of cold allodynia, mechanical and heat hyperalgesia, dynamic mechanical allodynia, and functional deficit in walking along with rise in the levels of TBARS and TNF-alpha. Administration of MC (200, 400, and 800 mg/kg) significantly attenuated TST-induced behavioural and biochemical changes. Furthermore, pretreatment of BADGE (120 mg/kg, intraperitoneally) abolished the protective effect of MC in TST-induced neuropathic pain. Collectively, it is speculated that PPAR-gamma agonistic activity, anti-inflammatory, and antioxidative potential is critical for antinociceptive effect of MC in neuropathic pain.

  3. Can Accelerators Accelerate Learning?

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-01-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  4. Can Accelerators Accelerate Learning?

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

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

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

    2012-02-17

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

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

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

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

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

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

    1990-01-01

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

  8. MR imaging findings of medial tibial crest friction

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

    2013-01-01

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

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

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

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

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

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

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

  12. MR imaging findings of medial tibial crest friction

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

    2013-11-01

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

  13. Accelerated reliability testing of highly aligned single-walled carbon nanotube networks subjected to DC electrical stressing.

    Strus, Mark C; Chiaramonti, Ann N; Kim, Young Lae; Jung, Yung Joon; Keller, Robert R

    2011-07-01

    We investigate the electrical reliability of nanoscale lines of highly aligned, networked, metallic/semiconducting single-walled carbon nanotubes (SWCNTs) fabricated through a template-based fluidic assembly process. We find that these SWCNT networks can withstand DC current densities larger than 10 MA cm(-2) for several hours and, in some cases, several days. We develop test methods that show that the degradation rate, failure predictability and total device lifetime can be linked to the initial resistance. Scanning electron and transmission electron microscopy suggest that fabrication variability plays a critical role in the rate of degradation, and we offer an empirical method of quickly determining the long-term performance of a network. We find that well-fabricated lines subject to constant electrical stress show a linear accumulation of damage reminiscent of electromigration in metallic interconnects, and we explore the underlying physical mechanisms that could cause such behavior.

  14. Plasma accelerators

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  15. Accumulation of carbonyls accelerates the formation of pentosidine, an advanced glycation end product: carbonyl stress in uremia.

    Miyata, T; Ueda, Y; Yamada, Y; Izuhara, Y; Wada, T; Jadoul, M; Saito, A; Kurokawa, K; van Ypersele de Strihou, C

    1998-12-01

    Advanced glycation end product (AGE) formation is related to hyperglycemia in diabetes but not in uremia, because plasma AGE levels do not differ between diabetic and nondiabetic hemodialysis patients. The mechanism of this phenomenon remains elusive. Previously, it was suggested that elevation of AGE levels in uremia might result from the accumulation of unknown AGE precursors. The present study evaluates the in vitro generation of pentosidine, a well identified AGE structure. Plasma samples from healthy subjects and nondiabetic hemodialysis patients were incubated under air for several weeks. Pentosidine levels were determined at intervals by HPLC assay. Pentosidine rose to a much larger extent in uremic than in control plasma. Pentosidine yield, i.e., the change in pentosidine level between 0 and 4 wk divided by 28 d, averaged 0.172 nmol/ml per d in uremic versus 0.072 nmol/ml per d in control plasma (P aminoguanidine and OPB-9195, which inhibit the Maillard reaction, lowered pentosidine yield in both uremic and control plasma. When ultrafiltrated plasma was exposed to 2,4-dinitrophenylhydrazine, the yield of hydrazones, formed by interaction with carbonyl groups, was markedly higher in uremic than in control plasma. These observations strongly suggest that the pentosidine precursors accumulated in uremic plasma are carbonyl compounds. These precursors are unrelated to glucose or ascorbic acid, whose concentration is either normal or lowered in uremic plasma. They are also unrelated to 3-deoxyglucosone, a glucose-derived dicarbonyl compound whose level is raised in uremic plasma: Its addition to normal plasma fails to increase pentosidine yield. This study reports an elevated level of reactive carbonyl compounds ("carbonyl stress") in uremic plasma. Most have a lower than 5000 Da molecular weight and are thus partly removed by hemodialysis. Their effect on pentosidine generation can be inhibited by aminoguanidine or OPB-9195. Carbonyl stress might contribute to

  16. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics

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

    Guzik, Grzegorz

    2011-01-01

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

  18. Initiating running barefoot: Effects on muscle activation and impact accelerations in habitually rearfoot shod runners.

    Lucas-Cuevas, Angel Gabriel; Priego Quesada, José Ignacio; Giménez, José Vicente; Aparicio, Inma; Jimenez-Perez, Irene; Pérez-Soriano, Pedro

    2016-11-01

    Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.

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

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

    2017-07-01

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

  20. Accelerator Service

    Champelovier, Y.; Ferrari, M.; Gardon, A.; Hadinger, G.; Martin, J.; Plantier, A.

    1998-01-01

    Since the cessation of the operation of hydrogen cluster accelerator in July 1996, four electrostatic accelerators were in operation and used by the peri-nuclear teams working in multidisciplinary collaborations. These are the 4 MV Van de Graaff accelerator, 2,5 MV Van de Graaff accelerator, 400 kV ion implanter as well as the 120 kV isotope separator

  1. Fracture reduction and primary ankle arthrodesis: a reliable approach for severely comminuted tibial pilon fracture.

    Beaman, Douglas N; Gellman, Richard

    2014-12-01

    Posttraumatic arthritis and prolonged recovery are typical after a severely comminuted tibial pilon fracture, and ankle arthrodesis is a common salvage procedure. However, few reports discuss the option of immediate arthrodesis, which may be a potentially viable approach to accelerate overall recovery in patients with severe fracture patterns. (1) How long does it take the fracture to heal and the arthrodesis to fuse when primary ankle arthrodesis is a component of initial fracture management? (2) How do these patients fare clinically in terms of modified American Orthopaedic Foot and Ankle Society (AOFAS) scores and activity levels after this treatment? (3) Does primary ankle arthrodesis heal in an acceptable position when anterior ankle arthrodesis plates are used? During a 2-year period, we performed open fracture reduction and internal fixation in 63 patients. Eleven patients (12 ankles) with severely comminuted high-energy tibial pilon fractures were retrospectively reviewed after surgical treatment with primary ankle arthrodesis and fracture reduction. Average patient age was 58 years, and minimum followup was 6 months (average, 14 months; range, 6-22 months). Anatomically designed anterior ankle arthrodesis plates were used in 10 ankles. Ring external fixation was used in nine ankles with concomitant tibia fracture or in instances requiring additional fixation. Clinical evaluation included chart review, interview, the AOFAS ankle-hindfoot score, and radiographic evaluation. All of the ankle arthrodeses healed at an average of 4.4 months (range, 3-5 months). One patient had a nonunion at the metaphyseal fracture, which healed with revision surgery. The average AOFAS ankle-hindfoot score was 83 with 88% having an excellent or good result. Radiographic and clinical analysis confirmed a plantigrade foot without malalignment. No patients required revision surgery for malunion. Primary ankle arthrodesis combined with fracture reduction for the severely comminuted

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

    Mullaji Arun

    2008-01-01

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

  3. Stress

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  4. Stress !!!

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  5. Near-Surface Sensing of Vegetative Heavy Metal Stress: Method Development for an Accelerated Assessment of Mine Tailing Waste and Remediation Efforts

    Lee, M. T.; Gottfried, M.; Berglund, E.; Rodriguez, G.; Ceckanowicz, D. J.; Cutter, N.; Badgeley, J.

    2014-12-01

    The boom and bust history of mineral extraction in the American southwest is visible today in tens of thousands of abandoned and slowly decaying mine installations that scar the landscape. Mine tailing piles, mounds of crushed mineral ore, often contain significant quantities of heavy metal elements which may leach into surrounding soils, surface water and ground water. Chemical analysis of contaminated soils is a tedious and time-consuming process. Regional assessment of heavy metal contamination for treatment prioritization would be greatly accelerated by the development of near-surface imaging indices of heavy-metal vegetative stress in western grasslands. Further, the method would assist in measuring the ongoing effectiveness of phytoremedatian and phytostabilization efforts. To test feasibility we ground truthed nine phytoremediated and two control sites sites along the mine-impacted Kerber Creek watershed in Saguache County, Colorado. Total metal concentration was determined by XRF for both plant and soil samples. Leachable metals were extracted from soil samples following US EPA method 1312. Plants were identified, sorted into roots, shoots and leaves, and digested via microwave acid extraction. Metal concentrations were determined with high accuracy by ICP-OES analysis. Plants were found to contain significantly higher concentrations of heavy metals than surrounding soils, particularly for manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), barium (Ba), and lead (Pb). Plant species accumulated and distributed metals differently, yet most showed translocation of metals from roots to above ground structures. Ground analysis was followed by near surface imaging using an unmanned aerial vehicle equipped with visible/near and shortwave infrared (0.7 to 1.5 μm) cameras. Images were assessed for spectral shifts indicative of plant stress and attempts made to correlate results with measured soil and plant metal concentrations.

  6. Electrostatic accelerator dielectrics

    Cooke, C.M.

    1989-05-01

    High voltage insulation problems in electrostatic accelerators are discussed. The aim of the analysis is to broaden the knowledge, highlight the characteristics of insulation technology and design strategies to improve use. The basic geometry of the insulation in accelerators is considered. A detailed description of each of the insulation regions is provided. The gas gap insulation of the terminal voltage is found to be sensitive to regions of high electric stress. In order to obtain satisfactory performance from solid support insulation, the attention is focused on the electric stress value and distribution. Potential subjects for discussion and further investigations are given

  7. Asymmetry in gait pattern following tibial shaft fractures

    Larsen, Peter; Læssøe, Uffe; Rasmussen, Sten

    2017-01-01

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

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

    Rakesh John

    2018-06-01

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

  9. MR evaluation of femoral neck version and tibial torsion

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

    2012-01-15

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

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

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

    2002-01-01

    Tibial intercondylar eminence (TIE) fractures are well described in the pediatric orthopedic literature. Adult TIEs are much less common, and limited literature exists on the subject. Adult knee hyperextension injuries commonly result in anterior cruciate ligament (ACL) injury; however, with significant trauma, a TIE enters the differential diagnosis. Identification and classification of TIE fractures typically has been provided by radiography. The incidence of concomitant injuries with magnetic resonance (MR) imaging in patients with adult TIE fractures has not been determined. We present a case of an adult type III TIE fracture seen on radiography that only with further MR imaging revealed a concomitant lateral tibial plateau fracture. Utilization of MR imaging altered the surgeon's course of treatment and postoperative care. Radiographic and MR images and a review of the literature are provided. (orig.)

  11. Tibial shaft fracture and ankle injury - Case report

    Caio Zamboni

    Full Text Available ABSTRACT The authors report on a case of tibial shaft fracture associated with ankle injury. The clinical, radiological and surgical characteristics are discussed. Assessment of associated injuries is often overlooked and these injuries are hard to diagnose. When torque occurs in the lower limb, the ankle becomes susceptible to simultaneous injury. It is essential to make careful assessment based on clinical, radiographic, intraoperative and postoperative characteristics in order to attain functional recovery.

  12. Human tibial torsion - Morphometric assessment and clinical relevance

    Swati Gandhi

    2014-02-01

    Full Text Available Background: Tibial torsion is an important anatomical parameter in clinical practice and displays variability among individuals. These variations are extremely significant in view of alignment guides such as those related to rotational landmarks of tibia in total knee arthroplasty. Further, precise knowledge and information pertaining to angle of tibial torsion also helps in correction of traumatic malunion or congenital maltorsion of tibia. Methods: The present study was carried out to determine the angle of tibial torsion in 100 adult dry tibia bones in the Department of Anatomy, Government Medical College, Amritsar. The study group comprised 50 males and 50 females with equal number of right- and left-sided bones. The measurements were meticulously recorded and the data were subjected to statistical analysis. The results were analyzed and discussed in the light of existing literature. Results: On the right side, it was found to be 29.84° ± 4.86°° (range = 22.00° -38.00° in males and 28.92° ± 5.10°° (range = 15.00°-38.00° in females. On the left side, it was found to be 28.00° ± 4.94°° (range = 20.00°-40.00°° in males and 28.12° ± 4.28°° (range = 20.00°-37.00°° in females. Conclusion: The present study is an endeavor to provide baseline data with reference to the angle of tibial torsion in the Indian population. The results of the study assume special importance in view of the technical advancements in reconstructive surgical procedures in orthopedic practice.

  13. Treatment of segmental tibial fractures with supercutaneous plating.

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

    2014-08-01

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

  14. Scintigraphic diagnosis of stress-induced incomplete fractures of the proximal tibia

    Collier, B.D.; Johnson, R.P.; Carrera, G.F.; Akhtar, K.; Isitman, A.T.

    1984-01-01

    Incomplete stress fractures of the proximal tibial diaphysis can be diagnosed by bone scintigraphy. The scintigraphic appearance of incomplete rather than complete tibial stress fractures is apparently reported for the first time in this article. With no treatment other than restricted activity, this injury heals rapidly and completely in 4 to 6 weeks. The major threat to the patient's welfare is unfounded suspicion of tumor or infection which may lead to biopsy or inappropriate therapy

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

    Zimmermann, V

    2014-01-01

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

  16. Stress !!!

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  17. Ilizarov bone transport versus fibular graft for reconstruction of tibial bone defects in children.

    Abdelkhalek, Mostafa; El-Alfy, Barakat; Ali, Ayman M

    2016-11-01

    The aim of this study was to compare the results of treatment of segmental tibial defects in the pediatric age group using an Ilizarov external fixator versus a nonvascularized fibular bone graft. This study included 24 patients (age range from 5.5 to 15 years) with tibial bone defects: 13 patients were treated with bone transport (BT) and 11 patients were treated with a nonvascularized fibular graft (FG). The outcome parameters were bone results (union, deformity, infection, leg-length discrepancy) and functional results: external fixation index and external fixation time. In group A (BT), one patient developed refracture at the regenerate site, whereas, in group B (FG), after removal of the external fixator, one of the FGs developed a stress fracture. The external fixator time in group A was 10.7 months (range 8-14.5) versus 7.8 months (range 4-11.5 months) in group B (FG). In group A (BT), one patient had a limb-length discrepancy (LLD), whereas, in group B (FG), three patients had LLD. The functional and bone results of the Ilizarov BT technique were excellent in 23.1 and 30.8%, good in 38.5 and 46.2, fair in 30.8 and 15.4, and poor in 7.6 and 7.6%, respectively. The poor functional result was related to the poor bone result because of prolonged external fixator time resulting in significant pain, limited ankle motion, whereas the functional and bone results of fibular grafting were excellent in 9.1 and 18.2%, good in 63.6 and 45.5%, fair in 18.2 and 27.2%, and poor in 9.1 and 9.1%, respectively. Segmental tibial defects can be effectively treated with both methods. The FG method provides satisfactory results, with early removal of the external fixator. However, it had a limitation in patients with severe infection and those with LLD. Also, it requires a long duration of limb bracing until adequate hypertrophy of the graft. The Ilizarov method has the advantages of early weight bearing, treatment of postinfection bone defect in a one-stage surgery, and the

  18. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  19. Aneurisma verdadeiro bilateral de artéria tibial posterior True bilateral aneurysm of the posterior tibial artery

    Silvio Romero de Barros Marques

    2006-03-01

    Full Text Available Neste artigo, faz-se o relato de um caso de aneurisma verdadeiro bilateral da artéria tibial posterior em paciente de 57 anos. Os aneurismas surgiram em épocas diferentes. Os aspectos clínicos, diagnósticos e terapêuticos deste caso são discutidos. Este relato é importante, pois os autores não têm conhecimento de caso semelhante na literatura consultada.This article reports a case of true bilateral aneurysm of the tibial posterior artery in a 57 year-old patient. The aneurysms occurred at different times. The clinical, diagnostic and therapeutic aspects of this case are discussed. This report is important because the authors did not find a similar description in the literature.

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

    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.

  1. Arthroscopic treatment of displaced tibial eminence fractures using a suspensory fixation

    Philippe Loriaut

    2017-01-01

    Conclusion: The arthroscopic treatment of displaced tibial intercondylar eminence fractures using a suspensory system provided a satisfactory clinical and radiological outcome at a followup of 2 years.

  2. The Tibial Slope in Patients With Achondroplasia: Its Characterization and Possible Role in Genu Recurvatum Development.

    Brooks, Jaysson T; Bernholt, David L; Tran, Kevin V; Ain, Michael C

    2016-06-01

    Genu recurvatum, a posterior resting position of the knee, is a common lower extremity deformity in patients with achondroplasia and has been thought to be secondary to ligamentous laxity. To the best of our knowledge, the role of the tibial slope has not been investigated, and no studies describe the tibial slope in patients with achondroplasia. Our goals were to characterize the tibial slope in children and adults with achondroplasia, explore its possible role in the development of genu recurvatum, and compare the tibial slope in patients with achondroplasia to that in the general population. We reviewed 252 lateral knee radiographs of 130 patients with achondroplasia seen at our clinic from November 2007 through September 2013. Patients were excluded if they had previous lower extremity surgery or radiographs with extreme rotation. We analyzed patient demographics and, on all radiographs, the tibial slope. We then compared the mean tibial slope to norms in the literature. Tibial slopes >90 degrees had an anterior tibial slope and received a positive prefix. Statistical analysis included intraclass and interclass reliability, Pearson correlation coefficient, and the Student t tests (significance, Pachondroplasia than in the general population; however, this difference diminishes as patients' age. An anterior tibial slope may predispose to a more posterior resting knee position, also known as genu recurvatum. Level IV-retrospective case series.

  3. Preoperative Measurement of Tibial Resection in Total Knee Arthroplasty Improves Accuracy of Postoperative Limb Alignment Restoration

    Pei-Hui Wu

    2016-01-01

    Conclusions: Using conventional surgical instruments, preoperative measurement of resection thickness of the tibial plateau on radiographs could improve the accuracy of conventional surgical techniques.

  4. Effect of tibial slope on the stability of the anterior cruciate ligament-deficient knee.

    Voos, James E; Suero, Eduardo M; Citak, Musa; Petrigliano, Frank P; Bosscher, Marianne R F; Citak, Mustafa; Wickiewicz, Thomas L; Pearle, Andrew D

    2012-08-01

    We aimed to quantify the effect of changes in tibial slope on the magnitude of anterior tibial translation (ATT) in the anterior cruciate ligament (ACL)-deficient knee during the Lachman and mechanized pivot shift tests. We hypothesized that increased posterior tibial slope would increase the amount of ATT of an ACL-deficient knee, while leveling the slope of the tibial plateau would decrease the amount of ATT. Lachman and mechanized pivot shift tests were performed on hip-to-toe cadaveric specimens, and ATT of the lateral and the medial compartments was measured using navigation (n = 11). The ACL was then sectioned. Stability testing was repeated, and ATT was recorded. A proximal tibial osteotomy in the sagittal plane was then performed achieving either +5 or -5° of tibial slope variation after which stability testing was repeated (n = 10). Sectioning the ACL resulted in a significant increase in ATT in both the Lachman and mechanized pivot shift tests (P slope of the tibial plateau had no effect on ATT during the Lachman test (n.s.). During the mechanized pivot shift tests, a 5° increase in posterior slope resulted in a significant increase in ATT compared to the native knee (P slope reduced ATT to a level similar to that of the intact knee. Tibial slope changes did not affect the magnitude of translation during a Lachman test. However, large changes in tibial slope variation affected the magnitude of the pivot shift.

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

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

    2007-09-01

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

  6. Stress fractures in military training

    Jofre, M.J.; Sierralta, M.P.

    2002-01-01

    During military training, the incidence of overuse injuries like stress fractures increase. The aim of the study was to investigate the utility of bone scan in a military population with clinical suspected stress fractures or periostitis. Material and methods: A three-year retrospective analysis was made on patients who were clinically diagnosed with stress fractures at the Military Hospital Nuclear Medicine Department. Thirty-seven patients were studied (mean age 23. +/- 8 y.o; 31 males), 28 cases of which (76%) had tibial stress syndrome. Other localizations were lumbar spine, femoral, fibular, tarsal or metatarsal. Bone scintigraphy was performed injecting 1036 MBq of Tc99m-MDP i.v. Whole body images and lateral projections of lower extremities were done. Results: Bone scan in tibial syndrome was positive for 23 cases (82%), 65% of them were bilateral and 13% also had femoral injuries. X-rays were done in 10 cases and were all negative. In other localizations, the bone scans were negative, but demonstrated other degenerative lesions. All stress fractures were conservatively treated with non-steroidal anti-inflammatories and suspension of physical activity. Conclusions: Bone scan is a reliable confirmatory tool for tibial stress syndrome diagnosis. In addition, it helps to determine both the severity and extension of the injury as well as support the indication of rest in the military population

  7. Stress fractures in military training

    Jofre, M J; Sierralta, M P [Military Hospital Nuclear Medicine Department, Santiago (Chile)

    2002-09-01

    During military training, the incidence of overuse injuries like stress fractures increase. The aim of the study was to investigate the utility of bone scan in a military population with clinical suspected stress fractures or periostitis. Material and methods: A three-year retrospective analysis was made on patients who were clinically diagnosed with stress fractures at the Military Hospital Nuclear Medicine Department. Thirty-seven patients were studied (mean age 23. +/- 8 y.o; 31 males), 28 cases of which (76%) had tibial stress syndrome. Other localizations were lumbar spine, femoral, fibular, tarsal or metatarsal. Bone scintigraphy was performed injecting 1036 MBq of Tc99m-MDP i.v. Whole body images and lateral projections of lower extremities were done. Results: Bone scan in tibial syndrome was positive for 23 cases (82%), 65% of them were bilateral and 13% also had femoral injuries. X-rays were done in 10 cases and were all negative. In other localizations, the bone scans were negative, but demonstrated other degenerative lesions. All stress fractures were conservatively treated with non-steroidal anti-inflammatories and suspension of physical activity. Conclusions: Bone scan is a reliable confirmatory tool for tibial stress syndrome diagnosis. In addition, it helps to determine both the severity and extension of the injury as well as support the indication of rest in the military population.

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

    Chandra Sekharam Naidu

    2015-05-01

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

  9. Biomechanical evaluation of tibial bone adaptation after revision total knee arthroplasty: A comparison of different implant systems.

    María Paz Quilez

    Full Text Available The best methods to manage tibial bone defects following total knee arthroplasty remain under debate. Different fixation systems exist to help surgeons reconstruct knee osseous bone loss (such as tantalum cones, cement, modular metal augments, autografts, allografts and porous metaphyseal sleeves However, the effects of the various solutions on the long-term outcome remain unknown. In the present work, a bone remodeling mathematical model was used to predict bone remodeling after total knee arthroplasty (TKA revision. Five different types of prostheses were analyzed: one with a straight stem; two with offset stems, with and without supplements; and two with sleeves, with and without stems. Alterations in tibia bone density distribution and implant Von Mises stresses were quantified. In all cases, the bone density decreased in the proximal epiphysis and medullary channels, and an increase in bone density was predicted in the diaphysis and around stem tips. The highest bone resorption was predicted for the offset prosthesis without the supplement, and the highest bone formation was computed for the straight stem. The highest Von Mises stress was obtained for the straight tibial stem, and the lowest was observed for the stemless metaphyseal sleeves prosthesis. The computational model predicted different behaviors among the five systems. We were able to demonstrate the importance of choosing an adequate revision system and that in silico models may help surgeons choose patient-specific treatments.

  10. Long-term complications following tibial plateau levelling osteotomy in small dogs with tibial plateau angles > 30°.

    Knight, Rebekah; Danielski, Alan

    2018-04-21

    Tibial plateau levelling osteotomy (TPLO) is commonly performed for surgical management of cranial cruciate ligament (CCL) disease. It has been suggested that small dogs may have steeper tibial plateau angles (TPAs) than large dogs, which has been associated with increased complication rates after TPLO. A retrospective study was performed to assess the rate and nature of long-term complications following TPLO in small dogs with TPAs>30°. Medical records were reviewed for dogs with TPAs>30° treated for CCL rupture by TPLO with a 2.0 mm plate over a five-year period. Radiographs were assessed to determine TPA, postoperative tibial tuberosity width and to identify any complication. Up-to-date medical records were obtained from the referring veterinary surgeon and any complications in the year after surgery were recorded. The effects of different variables on complication rate were assessed using logistic regression analysis. Minor complications were reported in 22.7 per cent of cases. This is similar to or lower than previously reported complication rates for osteotomy techniques in small dogs and dogs with steep TPAs. A smaller postoperative TPA was the only variable significantly associated with an increased complication rate. No major complications were identified. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. The influence of gamma radiation on HDPE properties for tibial tray

    Sulistioso, G.S.; Dewi, R.K.; Maria, C.P.; Nada, M.

    2012-01-01

    A research on HDPE as tibial tray in total knee joint replacement surgery has been done. The aims of this research were to characterize the influence of gamma radiation on chemical, and mechanical properties on HDPE is made by using hot press method then irradiated with various doses of gamma rays of 0 kGy, 25 kGy, 50 kGy, 75 kGy, 100 kGy, 125 kGy, and 150 kGy at a dose rate 9 kGy/h. The irradiated HDPE were tested for their chemical, and mechanical properties. The chemical properties test, involve crosslinking and free radicals. The mechanical properties test, involve hardness, tensile strength, and elongation at break. The results showed that gamma radiation from IRKA IV th category can enhance the, chemical properties of HDPE in terms of percentage and number of radical crosslinking and mechanical properties of HDPE in terms of hardness, tensile strength and elongation at break with different changes from the initial state before radiation also the optimum dose to obtain better physical, chemical, and mechanical properties of HDPE, crosslinking percentage at 99.71%; height of radical peroxide curve at 13 cm; hardness (shore A) at 94.33; modulus of elasticity at 1113.03 N/mm 2 ; yield stress at 26.38 N/mm 2 ; tensile strength at 31.11 N/mm 2 ; and elongation at break at 440.37%, so that HDPE can be used as tibial tray. (author)

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

    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.

  13. Mediolateral Differences of Proteoglycans Distribution at the ACL Tibial Footprint: Experimental Study of 16 Cadaveric Knees

    Joon Ho Wang

    2018-01-01

    Full Text Available This study aimed to identify the staining pattern of ACL attachment blended with cartilage of the medial tibial plateau at the tibial insertion and histologically characterize the tibial footprint. Sixteen fresh frozen cadaveric knees (mean age: 52.0±6.2 years were used for this study. The specimens were bisected in the coronal plane, in accordance with the fiber orientation of the ACL tibial attachment. Adjacent sections were then stained with hematoxylin and eosin (H&E to observe the morphology of the ACL insertion and with fast green and Safranin-O protocols to evaluate for collagen and proteoglycans (PG. The insertion area on the tibial footprint was divided into five zones in the medial to lateral direction, which was determined by division of the section from most prominent medial tibial spine to most lateral margin of ACL attachment. Then rectangular area with a vertical length that is twice the width of respective five zones was set. Stained areas of all images were quantified positively by using ImageJ software, and the value for staining area measured was defined in percentage by multiplying whole image area by 100. The mean proportion of Safranin-O staining is significantly greater nearer to the medial tibial spine (59% in zone 1, 32% in zone 2, 13% in zone 3, 13% in zone 4, and 4% in zone 5, P<0.001. The medial section of the tibial insertion area grew in size and increased in PG staining with more densely organized collagen arrangement with more fibrocartilage cells. The ACL tibial insertion showed a medially eccentric staining pattern by histological evaluation of the ACL attachment to cartilage. Our histological results of the eccentric biomaterial property in the medial tibial spine of ACL insertion area can be considered in making a more functional anatomic tibial tunnel placement.

  14. Stress.

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  15. Quadriceps force and anterior tibial force occur obviously later than vertical ground reaction force: a simulation study

    Ueno, Ryo; Ishida, Tomoya; Yamanaka, Masanori; Taniguchi, Shohei; Ikuta, Ryohei; Samukawa, Mina; Saito, Hiroshi; Tohyama, Harukazu

    2017-01-01

    Background: Although it is well known that quadriceps force generates anterior tibial force, it has been unclear whether quadriceps force causes great anterior tibial force during the early phase of a landing task. The purpose of the present study was to examine whether the quadriceps force induced great anterior tibial force during the early phase of a landing task. Methods: Fourteen young, healthy, female subjects performed a single-leg landing task. Muscle force and anterior tibial force w...

  16. The effect of posterior tibial slope on simulated laxity tests in cruciate-retaining TKA

    Marra, Marco A.; Strzelczak, Marta; Heesterbeek, Petra J.C.; van de Groes, Sebastiaan; Janssen, Dennis; Koopman, Bart F.J.M.; Wymenga, Ate B.; Verdonschot, Nico

    2017-01-01

    INTRODUCTION: Tibial slope can affect the outcomes of Total Knee Arthroplasty (TKA). More posterior slope potentially helps releasing a too tight flexion gap and it is generally associated with a wider range of post-operative knee flexion. However, the mechanism by which tibial slope affects the

  17. Negative pressure wound therapy for Gustilo Anderson grade IIIb open tibial fractures

    Chul Hyun Park

    2016-01-01

    Conclusion: Staged treatment using NPWT decreased the risks of infection and requirement of flap surgeries in Gustilo Anderson grade IIIb open tibial fractures. Therefore, staged treatment using NPWT could be a useful treatment option for Gustilo Anderson grade IIIb open tibial fractures.

  18. Metachronous Bilateral Posterior Tibial Artery Aneurysms in Ehlers-Danlos Syndrome Type IV

    Hagspiel, Klaus D.; Bonatti, Hugo; Sabri, Saher; Arslan, Bulent; Harthun, Nancy L.

    2011-01-01

    Ehlers-Danlos syndrome type IV is a life-threatening genetic connective tissue disorder. We report a 24-year-old woman with EDS-IV who presented with metachronous bilateral aneurysms/pseudoaneurysms of the posterior tibial arteries 15 months apart. Both were treated successfully with transarterial coil embolization from a distal posterior tibial approach.

  19. Management of open tibial fractures – a regional experience

    Townley, WA; Nguyen, DQA; Rooker, JC; Dickson, JK; Goroszeniuk, DZ; Khan, MS; Camp, D

    2010-01-01

    INTRODUCTION The treatment of soft-tissue injuries associated with tibial diaphyseal fractures presents a clinical challenge that is best managed by a combined plastic and orthopaedic surgery approach. The current study was undertaken to assess early treatment outcomes and burden of service provision across five regional plastic surgery units in the South-West of England. SUBJECTS AND METHODS We conducted a prospective 6-month audit of open tibial diaphyseal fracture management in five plastic surgery units (Bristol, Exeter, Plymouth, Salisbury, Swansea) with a collective catchment of 9.2 million people. Detailed data were collected on patient demographics, injury pattern, surgical management and outcome followed to discharge. RESULTS The study group consisted of 55 patients (40 male, 15 female). Twenty-two patients presented directly to the emergency department at the specialist hospital (primary group), 33 patients were initially managed at a local hospital (tertiary group). The mean time from injury to soft tissue cover was significantly less (P < 0.001) in the primary group (3.6 ± 0.8 days) than the tertiary group (10.8 ± 2.2 days), principally due to a delay in referral in the latter group (5.4 ±1.7 days). Cover was achieved with 39 flaps (19 free, 20 local), eight split skin grafts. Nine wounds closed directly or by secondary intention. There were 11 early complications (20%) including one flap failure and four infections. The overall mean length of stay was 17.5 ± 2.8 days. CONCLUSIONS Multidisciplinary management of severe open tibial diaphyseal may not be feasible at presentation of injury depending on local hospital specialist services available. Our results highlight the need for robust assessment, triage and senior orthopaedic review in the early post-injury phase. However, broader improvements in the management of lower limb trauma will additionally require further development of combined specialist trauma centres. PMID:21047449

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

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

    2013-02-01

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

  1. Electrostatic accelerators

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  2. Electrostatic accelerators

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  3. Accelerator development

    Anon.

    1975-01-01

    Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

  4. Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP Synthesized from Porous Foraminifera Carbonate Macrospheres

    Joshua Chou

    2013-12-01

    Full Text Available Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.

  5. Outcomes of The Isolated Closed Tibial Shaft Fractures Treated Nonsurgically

    Dawood Jafari

    2011-05-01

    Full Text Available Background: Fractures of the tibia are important for their commonness and controversy in their management. Both conservative and surgical techniques have been introduced in an effort to speed time to union while minimizing the occurrence of complications. Standard treatment for low-energy tibial shaft fractures includes closed reduction and cast immobilization.The purpose of our study was to analyze retention of reduction after cast immobilization of simple isolated closed tibial fractures.Methods:All cases of the diagnosed isolated closed tibial shaft fracture treated non-surgically at Shafa Yahyaeian Hospital, between 2006 and 2009 were retrieved from medical records. We reviewed all medical records and radiographs of these patients to inquire about the patients’ demographic data used to analyze the outcomes of the non-surgical treatment.Results:Of the 26 patients examined, males were more commonly affected. The mean age was 27.46   (SD=7.58.The most common causes of injury were direct blow and motorcycle to pedestrian accident. Followup duration for each patient had an average of 9.12 months (SD=2.36. Using AO/OTA classification, distributed as 38.5% A1.1, 26.9% A2.1 and 34.6% A3.1 fractures. Most fractures were sustained in the lower third of the tibia (53.85%. All fractures eventually healed in an average of 13.7 weeks (SD=3.24. There was one case of delayed union in the 22nd week. In 92.3% of patients, shortening of bone was less than 1 cm, while in 7.7% patients, was more than 1.5 cm. We observed an anterior or posterior angulation > 10 ° in 2 (7.69% patients. Moreover, in 4 (15.38% patients we found varus angulation > 5°. Therefore, final deformity was observed in 8 (30.77% patients. No patient had non-union, rotational malalignment of more than 10 degrees, an infection, or a compartment syndrome.Conclusion : Our non-surgical treatment’s outcomes were not satisfactory, despite applying all principles for conservative treatment and

  6. CAS CERN Accelerator School: Advanced accelerator physics. Proceedings. Vol. 2

    Turner, S.

    1987-01-01

    This advanced course on general accelerator physics is the second of the biennial series given by the CERN Accelerator School and follows on from the first basic course given at Gif-sur-Yvette, Paris, in 1984. Stress is placed on the mathematical tools of Hamiltonian mechanics and the Vlasov and Fokker-Planck equations, which are widely used in accelerator theory. The main topics treated in this present work include: nonlinear resonances, chromaticity, motion in longitudinal phase space, growth and control of longitudinal and transverse beam emittance, space-charge effects and polarization. The seminar programme treats some specific accelerator techniques, devices, projects and future possibilities. (orig.)

  7. Tibial tunnel and pretibial cysts following ACL graft reconstruction: MR imaging diagnosis

    Ghazikhanian, Varand [Brigham and Women' s Hospital, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Beltran, Javier [Maimonides Medical Center, Brooklyn, NY (United States); Nikac, Violeta [Maimonides Medical Center, Department of Radiology, Brooklyn, NY (United States); Bencardino, Jenny T. [NYU Hospital for Joint Diseases, New York, NY (United States); Feldman, Marina

    2012-11-15

    Tunnel cyst formation is a rare complication after anterior cruciate ligament reconstruction, usually occurring 1-5 years post-operatively, which may occasionally be symptomatic. There are multiple proposed theories regarding the etiology of tunnel cysts. Theories include necrosis, foreign-body reaction, lack of complete graft osteo-integration, and intravasation of articular fluid. It is important to know if the tunnel cysts are communicating or not communicating with the joint, as surgical management may be different. Imaging characteristics on magnetic resonance images (MRI) include tibial tunnel widening, multilocular or unilocular cyst formation in the graft or tibial tunnel, with possible extension into the pretibial space, intercondylar notch, and/or popliteal fossa. The MR imaging differential diagnosis of tibial tunnel cysts includes infection, foreign-body granuloma, or tibial screw extrusion. Importantly, to the best of our knowledge, graft failure or instability has not been reported in association with tibial tunnel cysts. (orig.)

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

    Devgan Ashish

    2013-04-01

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

  9. Pseudoaneurysm of the Anterior Tibial Artery following Ankle Arthroscopy in a Soccer Player

    Ichiro Tonogai

    2017-01-01

    Full Text Available Ankle arthroscopy carries a lower risk of vascular complications when standard anterolateral and anteromedial portals are used. However, the thickness of the fat pad at the anterior ankle affords little protection for the thin-walled anterior tibial artery, rendering it susceptible to indirect damage during procedures performed on the anterior ankle joint. To our knowledge, only 11 cases of pseudoaneurysm involving the anterior tibial artery after ankle arthroscopy have been described in the literature. Here we reported a rare case of a 19-year-old soccer player who presented with pseudoaneurysm of the anterior tibial artery following ankle arthroscopy using an ankle distraction method and underwent anastomosis for the anterior tibial artery injury. Excessive distraction of the ankle puts the neurovascular structures at greater risk for iatrogenic injury of the anterior tibial artery during ankle arthroscopy. Surgeons should look carefully for postoperative ankle swelling and pain after ankle arthroscopy.

  10. Standing balance in people with trans-tibial amputation due to vascular causes: A literature review.

    Seth, Mayank; Lamberg, Eric

    2017-08-01

    Balance is an important variable to consider during the rehabilitation process of individuals with trans-tibial amputation. Limited evidence exists on the balance abilities of people with trans-tibial amputation due to vascular causes. The purpose of this article is to review literature and determine if standing balance is diminished in people with trans-tibial amputation due to vascular causes. Literature review. Data were obtained from PubMed, Google Scholar, OandP.org , CINHAL, and Science Direct. Studies were selected only if they included standing balance assessment of people with unilateral trans-tibial amputation due to vascular causes. The review yielded seven articles that met the inclusion criteria. The general test methodology required participants to stand still on force platforms, with feet together, while center of pressure or postural sway was recorded. According to the findings of this review, individuals with trans-tibial amputees due to vascular causes have diminished balance abilities. Limited evidence suggests their balance might be further diminished as compared to individuals with trans-tibial amputation due to trauma. Although the evidence is limited, because of the underlying pathology and presence of comorbidities in individuals with trans-tibial amputation due to vascular causes, one cannot ignore these findings, as even a minor injury from a fall may develop into a non-healing ulcer and affect their health and well-being more severely than individuals with trans-tibial amputation due to trauma. Clinical relevance Individuals with trans-tibial amputation due to vascular causes have diminished balance abilities compared to healthy individuals and individuals with trans-tibial amputation due to trauma. This difference should be considered when designing and fabricating prostheses. Prosthetists and rehabilitation clinicians should consider designing amputation cause-specific rehabilitation interventions, focussing on balance and other

  11. Segmental transports for posttraumatic lower extremity bone defects: are femoral bone transports safer than tibial?

    Liodakis, Emmanouil; Kenawey, Mohamed; Krettek, Christian; Ettinger, Max; Jagodzinski, Michael; Hankemeier, Stefan

    2011-02-01

    The long-term outcomes following femoral and tibial segment transports are not well documented. Purpose of the study is to compare the complication rates and life quality scores of femoral and tibial transports in order to find what are the complication rates of femoral and tibial monorail bone transports and if they are different? We retrospectively analyzed the medical records of 8 femoral and 14 tibial consecutive segment transports performed with the monorail technique between 2001 and 2008 in our institution. Mean follow-up was 5.1 ± 2.1 years with a minimum follow-up of 2 years. Aetiology of the defects was posttraumatic in all cases. Four femoral (50%) and nine tibial (64%) fractures were open. The Short Form-36 (SF-36) health survey was used to compare the life quality after femoral and tibial bone transports. The Mann-Whiney U test, Fisher exact test, and the Student's two tailed t-test were used for statistical analysis. P ≤ 0.05 was considered to be statistically significant. The tibial transport was associated with higher rates of severe complications and additional procedures (1.5 ± 0.9 vs. 3.4 ± 2.7, p = 0.048). Three patients of the tibial group were amputated because of recurrent infections and one developed a complete regenerate insufficiency that was treated with partial diaphyseal tibial replacement. Contrary to that none of patients of the femoral group developed a complete regenerate insufficiency or was amputated. Tibial bone transports have a higher rate of complete and incomplete regenerate insufficiency and can more often end in an amputation. The authors suggest systematic weekly controls of the CRP value and of the callus formation in patients with posttraumatic tibia bone transports. Further comparative studies comparing the results of bone transports with and without intramedullary implants are necessary.

  12. Tibial internal rotation negatively affects clinical outcomes in total knee arthroplasty: a systematic review.

    Panni, Alfredo Schiavone; Ascione, Francesco; Rossini, Marco; Braile, Adriano; Corona, Katia; Vasso, Michele; Hirschmann, Michael T

    2017-12-15

    The aim of this systematic review is to analyze the effect of tibial rotational alignment after total knee arthroplasty (TKA) on clinical outcomes and assess the eventual cut-off values for tibial TKA rotation leading to poor outcomes. A detailed and systematic search from 1997 to 2017 of the Pubmed, Medline, Cochrane Reviews, and the Google Scholar databases was performed using the keyword terms "total knee arthroplasty", "total knee replacement", "tibial alignment", "tibial malalignement", "tibial rotation", "rotational error", "axis", "angle", "tibial malrotation", "clinical outcome", in several combinations. The modified Coleman scoring methodology (mCMS) was used. All the primary TKAs studies analyzing correlation between clinical results and tibial rotation were included. Five articles met the inclusion criteria. A total of 333 arthroplasties were included in this review; 139 had tibial component malalignment, while 194 were in control groups. The mean age of patients was 67.3 (SD 0.57) years. The mean average postoperative follow-up delay was 34.7 months (range 21-70). The mean mCMS score was 59.2 points indicating good methodological quality in the included studies. Functional outcomes were assessed through KSS, OKS, KOOS and VAS, negatively related to tibial internal rotation. Our review confirmed that excessive internal rotation of the tibial TKA component represents a significant risk factor for pain and inferior functional outcomes after TKA (> 10° of internal rotation demonstrated the common value), since external rotation does not affect the results. However, a universal precise cut-off value has not been found in the available literature and there remains a debate about CT rotation assessment and surgical intra-operative landmarks. III.

  13. RECIRCULATING ACCELERATION

    BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.

    2000-01-01

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous

  14. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  15. Tibial Slope Strongly Influences Knee Stability After Posterior Cruciate Ligament Reconstruction: A Prospective 5- to 15-Year Follow-up.

    Gwinner, Clemens; Weiler, Andreas; Roider, Manoussos; Schaefer, Frederik M; Jung, Tobias M

    2017-02-01

    The reported failure rate after posterior cruciate ligament (PCL) reconstruction remains high. Previous studies have shown that the tibial slope (TS) influences sagittal plane laxity. Consequently, alterations of TS might have an effect on postoperative knee stability after PCL reconstruction. We hypothesized that flattening of TS is associated with increased posterior laxity after PCL reconstruction. Cohort study; Level of evidence 3. This study consisted of 48 patients who underwent PCL reconstruction in a single-surgeon series. Eight patients underwent an isolated PCL reconstruction, 27 patients underwent an additional posterolateral corner reconstruction, and 13 patients underwent a combined reconstruction of the PCL, anterior cruciate ligament, and posterolateral corner. Three blinded observers measured TS and the side-to-side difference (SSD) of posterior tibial translation (PTT) before and after PCL reconstruction using standardized stress radiographs. The minimum follow-up was 5 years. At a mean follow-up of 103 months (range, 65-187), the mean SSD of PTT was significantly reduced (10.9 ± 2.9 vs 4.9 ± 4.3 mm; P slope.

  16. Accelerating Inspire

    AUTHOR|(CDS)2266999

    2017-01-01

    CERN has been involved in the dissemination of scientific results since its early days and has continuously updated the distribution channels. Currently, Inspire hosts catalogues of articles, authors, institutions, conferences, jobs, experiments, journals and more. Successful orientation among this amount of data requires comprehensive linking between the content. Inspire has lacked a system for linking experiments and articles together based on which accelerator they were conducted at. The purpose of this project has been to create such a system. Records for 156 accelerators were created and all 2913 experiments on Inspire were given corresponding MARC tags. Records of 18404 accelerator physics related bibliographic entries were also tagged with corresponding accelerator tags. Finally, as a part of the endeavour to broaden CERN's presence on Wikipedia, existing Wikipedia articles of accelerators were updated with short descriptions and links to Inspire. In total, 86 Wikipedia articles were updated. This repo...

  17. Posterior coronal plating for tibial fractures: technique and advantages

    Montu Jain

    2014-04-01

    Full Text Available Objective:Tibial shaft fractures are straightforward to treat but when associated with soft tissue injury particularly at the nail entry/plate insertion site or there is significant comminution proximally or a large butterfly fragment/a second split component in the posterior coronal plane, it is a challenge to the treating surgeon. The aim of the present report is to describe the technique of posterior coronal plating in such a scenario and its advantages. Methods:Between July 2008 and June 2011, 12 patients were pro spectively treated by this approach using 4.5 mm broad dynamic compression plates. Results:The time of bony consolidation and full weight bearing averaged 21.7 weeks (range, 16-26 weeks. Patients were followed up for at least 24 months (range, 24-48 months. At 1 year postoper atively, no loss in reduction or alignment was observed. Mean Hospital for Lower Extremity Measurement Functional Score was 72.8 (range, 64-78. All patients were satisfied with their treatment outcomes. Conclusion:Direct posterior approach and fixation using prone position helps to visualise the fracture fragments and provide rigid fixation. The approach is simple and extensile easily, apart from advantages of less soft tissue and hardware problems compared to standard medial or lateral plating. Key words: Tibial fractures; Bone plates; Orthopedic procedures

  18. Thrombosed Popliteal Artery Pseudoaneurysm as Herald of Tibial Osteochondroma

    A.M. Ruales Romero

    Full Text Available Background: Osteochondroma is the most common non-malignant tumour of bone, accounting for approximately one third of benign lesions in the skeleton. They often develop around the knee in the distal femur and in the proximal tibia and fibula. They present as a painless slow growing mass during adolescence and have been reported to cause damage to adjacent structures such as blood vessels; arterial damage is more common than venous injury and is usually a result of compression, stretching, and rubbing of the arterial wall. Such lesions include stenosis, thrombosis, and pseudoaneurysm formation possibly causing lower limb claudication or acute limb ischemia. Methods: An 18 year old male patient with a 4 week history of pain, hematoma, and oedema of the left calf without previous trauma is reported. A computed tomography scan (CT revealed a large popliteal artery pseudoaneurysm and its close relationship to a protrusion of the proximal tibia. Results: The popliteal artery was repaired by an external saphenous patch and the exostosis was removed. The patient had palpable popliteal and distal pulses after surgery and during the first year follow-up. Conclusions: Tibial osteochondroma should be considered in the differential diagnosis in young patients, among the potential causes of pseudoaneurysm of the femoral or popliteal artery. Surgical repair should be performed to restore normal blood flow with resection of the exostosis to prevent recurrence. Keywords: Popliteal artery, Pseudoaneurysm, Tibial exostosis, Osteochondroma

  19. Free flap reconstructions of tibial fractures complicated after internal fixation.

    Nieminen, H; Kuokkanen, H; Tukiainen, E; Asko-Seljavaara, S

    1995-04-01

    The cases of 15 patients are presented where microvascular soft-tissue reconstructions became necessary after internal fixation of tibial fractures. Primarily, seven of the fractures were closed. Eleven fractures had originally been treated by open reduction and internal fixation using plates and screws, and four by intramedullary nailing. All of the patients suffered from postoperative complications leading to exposure of the bone or fixation material. The internal fixation material was removed and radical revision of dead and infected tissue was carried out in all cases. Soft tissue reconstruction was performed using a free microvascular muscle flap (11 latissimus dorsi, three rectus abdominis, and one gracilis). In eight cases the nonunion of the fracture indicated external fixation. The microvascular reconstruction was successful in all 15 patients. In one case the recurrence of deep infection finally indicated a below-knee amputation. In another case, chronic infection with fistulation recurred postoperatively. After a mean follow-up of 26 months the soft tissue coverage was good in all the remaining 13 cases. All the fractures united. Microvascular free muscle flap reconstruction of the leg is regarded as a reliable method for salvaging legs with large soft-tissue defects or defects in the distal leg. If after internal fixation of the tibial fracture the osteosynthesis material or fracture is exposed, reconstruction of the soft-tissue can successfully be performed by free flap transfer. By radical revision, external fixation, bone grafting, and a free flap the healing of the fracture can be achieved.

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

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

    2013-01-01

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

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

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

    2013-03-01

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

  2. An unusual stress fracture: Bilateral posterior longitudinal stress fracture of tibia

    Malkoc, Melih; Korkmaz, Ozgur; Ormeci, Tugrul; Oltulu, Ismail; Isyar, Mehmet; Mahirogulları, Mahir

    2014-01-01

    INTRODUCTION Stress fractures (SF) occur when healthy bone is subjected to cyclic loading, which the normal carrying range capacity is exceeded. Usually, stress fractures occur at the metatarsal bones, calcaneus, proximal or distal tibia and tends to be unilateral. PRESENTATION OF CASE This article presents a 58-year-old male patient with bilateral posterior longitudinal tibial stress fractures. A 58 years old male suffering for persistent left calf pain and decreased walking distance for las...

  3. Tibial and Femoral Tunnel Changes After ACL Reconstruction: A Prospective 2-Year Longitudinal MRI Study.

    Weber, Alexander E; Delos, Demetris; Oltean, Hanna N; Vadasdi, Katherine; Cavanaugh, John; Potter, Hollis G; Rodeo, Scott A

    2015-05-01

    Tunnel widening after anterior cruciate ligament reconstruction (ACL-R) is a well-accepted and frequent phenomenon, yet little is known regarding its origin or natural history. To prospectively evaluate the cross-sectional area (CSA) changes in tibial and femoral bone tunnels after ACL-R with serial MRI. Case series; Level of evidence, 4. Patients underwent arthroscopic ACL-R with the same surgeon, surgical technique, and rehabilitation protocol. Each patient underwent preoperative dual-energy x-ray absorptiometry and clinical evaluation, as well as postoperative time zero MRI followed by subsequent MRI and clinical examination, including functional and subjective outcome tests, at 6, 12, 24, 52, and 104 weeks. Tibial and femoral tunnel CSA was measured on each MRI at tunnel aperture (ttA and ftA), midsection (ttM and ftM), and exit (ttE and ftE). Logistic regression modeling was used to examine the predictive value of demographic data and preoperative bone quality (as measured by dual-energy x-ray absorptiometry) on functional outcome scores, manual and instrumented laxity measurements, and changes in tunnel area over time. Eighteen patients (including 12 men), mean age 35.5±8.7 years, underwent ACL-R. There was significant tunnel expansion at ttA and ftA sites 6 weeks postoperatively (P=.024 and .0045, respectively). Expansion continued for 24 weeks, with progressive tunnel narrowing thereafter. Average ttA CSA was significantly larger than ftA CSA at all times. The ttM significantly expanded after 6 weeks (P=.06); continued expansion to week 12 was followed by 21 months of reduction in tunnel diameter. The ftM and both ttE and ftE sites decreased in CSA over the 2 years. Median Lysholm and International Knee Documentation Committee scores significantly improved at final follow-up (P=.0083 and 1 year from time of injury) predicted increased tunnel widening and accelerated expansion in CSA (Pclinical outcome. Younger age, male sex, and delay from injury to ACL

  4. FMIT accelerator

    Armstrong, D.D.

    1983-01-01

    A 35-MeV 100-mA cw linear accelerator is being designed by Los Alamos for use in the Fusion Materials Irradiation Test (FMIT) Facility. Essential to this program is the design, construction, and evaluation of performance of the accelerator's injector, low-energy beam transport, and radio-frequency quadrupole sections before they are shipped to the facility site. The installation and testing of some of these sections have begun as well as the testing of the rf, noninterceptive beam diagnostics, computer control, dc power, and vacuum systems. An overview of the accelerator systems and the performance to date is given

  5. Electron accelerator

    Abramyan.

    1981-01-01

    The USSR produces an electron accelerator family of a simple design powered straight from the mains. The specifications are given of accelerators ELITA-400, ELITA-3, ELT-2, TEUS-3 and RIUS-5 with maximum electron energies of 0.3 to 5 MeV, a mean power of 10 to 70 kW operating in both the pulsed and the continuous (TEUS-3) modes. Pulsed accelerators ELITA-400 and ELITA-3 and RIUS-5 in which TESLA resonance transformers are used are characterized by their compact size. (Ha)

  6. Impact of Fixed-Bearing and Mobile-Bearing Tibial Insert in Unicondylar Knee Arthroplasty

    Mehmet Faruk Çatma

    2016-06-01

    Full Text Available INTRODUCTION: The aim of the study is to investigate the impact of fixed or mobile-bearing tibial inserts on patellofemoral arthrosis and evaluate which one to be preferred for patients with patellofemoral arthrosis. METHODS: Operated in our clinic between January 2009 and February 2013, 33 with patellofemoral arthritis together with anteromedial compartment arthritis were included in the study. Patellofemoral joints of patients were evaluated according to the scoring system defined by Fulkerson-Shea. RESULTS: Unicondylar knee arthroplasty with fixed-bearing tibial insertsand 22 (66,6% (male: 3, female: 19 and unicondylar knee arthroplasty with mobile-bearing tibial inserts 11 (33,9 % (male: 2, female: 9 were implanted.Average knee flexion was found to be 116,5 (100-135 degrees in 22 patients with mobile-bearing tibial inserts, and 114,5 (95-135 in 11 patients with fixed-bearing tibial inserts. DISCUSSION AND CONCLUSION: Patellofemoral arthrosis is an important factor for unicondylar knee arthroplasty prognosis and one of the determinants of patient satisfaction. Significantly less patellofemoral complaints were seen with UKA with fixed-bearing tibial insert compared to mobile-bearing tibial insert.

  7. Ultrasound Guidance in Performing a Tendoscopic Surgery to Treat Posterior Tibial Tendinitis: A Useful Tool?

    Akinobu Nishimura

    2016-01-01

    Full Text Available A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

  8. The accuracy of intramedullary tibial guide of sagittal alignment of PCL-substituting total knee arthroplasty.

    Han, Hyuk-Soo; Kang, Seung-Baik; Jo, Chris H; Kim, Sun-Hong; Lee, Jung-Ha

    2010-10-01

    Experimental and clinical studies on the accuracy of the intramedullary alignment method have produced different results, and few have addressed accuracy in the sagittal plane. Reported deviations are not only attributable to the alignment method but also to radiological errors. The purpose of this study was to evaluate the accuracy of the intramedullary alignment method in the sagittal plane using computed tomography (CT) and 3-dimensional imaging software. Thirty-one TKAs were performed using an intramedullary alignment method involving the insertion of a long 8-mm diameter rod into the medullary canal to the distal metaphysis of the tibia. All alignment instruments were set to achieve an ideal varus/valgus angle of 0° in the coronal plane and a tibial slope of 0° in the sagittal plane. The accuracy of the intramedullary alignment system was assessed by measuring the coronal tibial component angle and sagittal tibial slope angles, i.e., angles between the tibial anatomical axis and the tangent to the medial and lateral tibial plateau or the cut-surface. The mean coronal tibial component angle was 88.5° ± 1.2° and the mean tibial component slope in the sagittal plane was 1.6° ± 1.2° without anterior slope. Our intramedullary tibial alignment method, which involves passing an 8-mm diameter long rod through the tibial shaft isthmus, showed good accuracy (less than 3 degrees of variation and no anterior slope) in the sagittal plane in neutral or varus knees.

  9. Extramedullary versus intramedullary tibial cutting guides in megaprosthetic total knee replacement

    Karade Vikas

    2012-10-01

    Full Text Available Abstract Background In a standard total knee replacement, tibial component alignment is a key factor for the long term success of the surgery. The purpose of this study is to compare the accuracy of extramedullary and intramedullary tibial cutting guides used in indigenous and imported implants respectively, in positioning of the tibial components in megaprosthetic knee replacements. Methods A comparative study of the accuracy of extramedullary and intramedullary tibial cutting guides was carried out in 92 megaprosthetic knee replacements for distal femoral tumors. For the proximal tibia cut for tibial component placement, an extramedullary guide was used in 65 patients and an intramedullary guide was used in 27 patients. Tibial component alignment angles were measured in postoperative X-rays with the help of CAD software. Results There was more varus placement in coronal plane with extramedullary cutting guide (−1.18 +/− 2.4 degrees than the intramedullary guide (−0.34 +/− 2.31 degrees but this did not reach statistical significance. The goal of 90 +/− 2 degrees alignment of tibial component was achieved in 54% of patients in the extramedullary group versus 67% in the intramedullary group. In terms of sagittal plane alignment, extramedullary guide showed less accurate results (2.09 +/− 2.4 degrees than intramedullary guide (0.50 +/− 3.80 degrees for tibial component alignment, though 78% of patients were aligned within the goal of 0–5 degrees of tibial slope angle in extramedullary group versus 63% in intramedullary group. The mean error in the measurements due to rotation of the knee during taking the X-rays was less than 0.1 degrees and distribution of the X-rays with the rotation of knee was similar in both the groups. Conclusions Overall, in megaprosthetic knee replacement intramedullary guides gave more accurate results in sagittal plane and exhibited similar variability as of extramedullary guides in coronal plane.

  10. Value of lateral blood pool imaging in patients with suspected stress fractures of the tibia.

    Mohan, Hosahalli K; Clarke, Susan E M; Centenara, Martin; Lucarelli, Amanda; Baron, Daniel; Fogelman, Ignac

    2011-03-01

    To critically evaluate the use of lateral blood pool imaging in athletes with lower limb pain and with a clinical suspicion of stress fracture. Two experienced nuclear medicine physicians evaluated 3-phase bone scans using 99mTc-methylene diphosphonate performed in 50 consecutive patients referred from a specialist sports injury clinic for suspected tibial stress fracture. The vascularity to the tibia as seen on the blood pool (second phase) images in the anterior/posterior views was compared with the lateral/medial view assessments. Stress fractures were presumed to be present when on the delayed images (third phase) there was a focal or fusiform area of increased tracer uptake involving the tibial cortex. Shin splints which are a recognized cause of lower limb pain in athletes mimicking stress fracture were diagnosed if increased tracer uptake was seen extending along the posterior tibial surface with no significant focal or fusiform area of uptake within this. Inter-reviewer agreement for the assessment of vascularity was also assessed using Cohen's Kappa scores. Twenty-four stress fractures in 24 patients and 66 shin splints in 40 patients were diagnosed. In 18 patients stress fracture and shin splints coexisted. In 10 patients no tibial pathology was identified. Of the 24 patients diagnosed with stress fractures, lateral/medial blood pool imaging was superior in the assessment of blood pool activity (P tibial stress fractures, lateral views of the tibia provide the optimal method for evaluation of vascularity. Prospective studies with quantitative or semi-quantitative assessment of skeletal vascularity could provide supplementary information relating to the pathophysiology of stress fractures, for example, the time scale of vascular changes after a tibial stress fracture, and potentially could have clinical relevance as to the assessment of the severity of stress fractures and their prognosis.

  11. Horizontal Accelerator

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  12. Acceleration theorems

    Palmer, R.

    1994-06-01

    Electromagnetic fields can be separated into near and far components. Near fields are extensions of static fields. They do not radiate, and they fall off more rapidly from a source than far fields. Near fields can accelerate particles, but the ratio of acceleration to source fields at a distance R, is always less than R/λ or 1, whichever is smaller. Far fields can be represented as sums of plane parallel, transversely polarized waves that travel at the velocity of light. A single such wave in a vacuum cannot give continuous acceleration, and it is shown that no sums of such waves can give net first order acceleration. This theorem is proven in three different ways; each method showing a different aspect of the situation

  13. LINEAR ACCELERATOR

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  14. Intercalary bone segment transport in treatment of segmental tibial defects

    Iqbal, A.; Amin, M.S.

    2002-01-01

    Objective: To evaluate the results and complications of intercalary bone segment transport in the treatment of segmental tibial defects. Design: This is a retrospective analysis of patients with segmental tibial defects who were treated with intercalary bone segment transport method. Place and Duration of Study: The study was carried out at Combined Military Hospital, Rawalpindi from September 1997 to April 2001. Subjects and methods: Thirteen patients were included in the study who had developed tibial defects either due to open fractures with bone loss or subsequent to bone debridement of infected non unions. The mean bone defect was 6.4 cms and there were eight associated soft tissue defects. Locally made unilateral 'Naseer-Awais' (NA) fixator was used for bone segment transport. The distraction was done at the rate of 1mm/day after 7-10 days of osteotomy. The patients were followed-up fortnightly during distraction and monthly thereafter. The mean follow-up duration was 18 months. Results: The mean time in external fixation was 9.4 months. The m ean healing index' was 1.47 months/cm. Satisfactory union was achieved in all cases. Six cases (46.2%) required bone grafting at target site and in one of them grafting was required at the level of regeneration as well. All the wounds healed well with no residual infection. There was no residual leg length discrepancy of more than 20 mm nd one angular deformity of more than 5 degrees. The commonest complication encountered was pin track infection seen in 38% of Shanz Screws applied. Loosening occurred in 6.8% of Shanz screws, requiring re-adjustment. Ankle joint contracture with equinus deformity and peroneal nerve paresis occurred in one case each. The functional results were graded as 'good' in seven, 'fair' in four, and 'poor' in two patients. Overall, thirteen patients had 31 (minor/major) complications with a ratio of 2.38 complications per patient. To treat the bone defects and associated complications, a mean of

  15. From guidelines to standards of care for open tibial fractures.

    Trickett, R W; Rahman, S; Page, P; Pallister, I

    2015-09-01

    The standards for the management of open fractures of the lower limb published by the British Association of Plastic, Reconstructive and Aesthetic surgeons (BAPRAS) and British Orthopaedic Association (BOA) were introduced to improve the treatment received by patients after open injury to the lower limb. These Standards were released after BAPRAS/BOA published Guidelines for the management of open tibial fractures. We wished to determine the impact of these Standards upon the surgical management of open tibial fractures by comparing patients admitted to an orthoplastic centre in the 45 months concluding December 2009 (the Guidelines era) with those admitted during 2011 (the Standards era). Surgical procedures required during the first 30 days and 12 months after injury were determined. Cases were divided into 'directly admitted patients' (DAP) and 'transferred patients' (TP). Standards-era patients were divided further into those who had surgery exclusively at the orthoplastic centre (orthoplastic patients (OPP)) and those transferred after surgery (TASP). The number of TP trebled in frequency in the Standards era, 25% of whom were transferred before surgery. Significantly fewer surgical procedures were required for DAP and OPP groups compared with TP (and TASP) groups in both eras (Mann-Whitney U-test, p=0.05). DAP and OPP groups during the Standards era underwent the fewest procedures, with the vast majority of cases treated with two or fewer procedures in the first 12 months (88% and 80%, respectively, compared with 61% in the Guidelines era). In the Guidelines era, 44% of TP cases and in the Standards era 39% of TP and 29% of TASP groups underwent two or fewer procedures. Approximately two-thirds of open tibial fractures managed in our orthoplastic centre were patients transferred after surgery. The greatest impact of the Standards was evident for those who underwent surgery exclusively in the orthoplastic centre, reflecting a more deliberate combined strategy

  16. Workshop on Accelerator Operation (WAO 2001)

    Bailey, R.

    2001-01-01

    The 3rd Workshop on Accelerator Operation (WAO 2001) followed earlier workshops in 1996 and 1998. Most topics relevant for the efficient and effective operation of accelerators were covered. These included the tools and utilities necessary in the control rooms; the organization of accelerator operation (process monitoring, shift work, stress); the monitoring of beam quality; safety issues and standards; and questions particularly relevant for superconducting accelerators, in particular cryogenics. (author)

  17. Elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

    Turhan, Egemen; Ege, Ahmet; Keser, Selcuk; Bayar, Ahmet

    2008-10-01

    Elephantiasis nostras verrucosa represents an infrequent clinical entity with cutaneous changes characterized by dermal fibrosis, hyperkeratotic verrucous and papillamotous lesions resulting from chronic non-filarial lymphedema secondary to infections, surgeries, tumor obstruction, radiation, congestive heart failure, and obesity. Although recurrent streptococcal lymphangitis is believed to play a critical role in the origin of elephantiasis nostras verrucosa, the exact pathogenesis of the disorder is not yet clear. Therapeutic efforts should aim to reduce lymph stasis, which will also lead to improvement of the cutaneous changes but unfortunately there is no specific treatment for advanced cases. In this report, we present a patient who was treated by below knee amputation as a result of elephantiasis nostras verrucosa complicated with chronic tibial osteomyelitis.

  18. Double segmental tibial fractures - an unusual fracture pattern

    Bali Kamal

    2012-02-01

    Full Text Available 【Abstract】A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech- nique with a pleasing outcome. Key words: Fracture, bone; Tibia; Fibula; Nails

  19. Treatment preferences in Turkey for open fracture of the tibial diaphysis

    Güzelali Özdemir

    2017-03-01

    Conclusion: A wide variation was observed among orthopedics and traumatology specialists in Turkey regarding treatment of open tibial diaphysis fracture in adults. Data obtained from this study together with the available literature may be useful to further develop therapeutic approaches.

  20. Study of the anatomy of the tibial nerve and its branches in the distal medial leg

    Torres, André Leal Gonçalves; Ferreira, Marcus Castro

    2012-01-01

    Objective Determine, through dissection in fresh cadavers, the topographic anatomy of the tibial nerve and its branches at the ankle, in relation to the tarsal tunnel. Methods Bilateral dissections were performed on 26 fresh cadavers and the locations of the tibial nerve bifurcation and its branches were measured in millimeters. For the calcaneal branches, the amount and their respective nerves of origin were also analyzed. Results The tibial nerve bifurcation occurred under the tunnel in 88% of the cases and proximally in 12%. As for the calcaneal branches, the medial presented with one (58%), two (34%) and three (8%) branches, with the most common source occurring in the tibial nerve (90%) and the lower with a single branch per leg and lateral plantar nerve as the most common origin (70%). Level of Evidence, V Expert opinion. PMID:24453596

  1. What is the optimal alignment of the tibial and femoral components in knee arthroplasty?

    Gromov, Kirill; Korchi, Mounim; Thomsen, Morten G

    2014-01-01

    of positioning on survival and functional outcome was considered. Results - Many definitions exist when evaluating placement of femoral and tibial components. Implant alignment plays a role in both survival and functional outcome following primary TKA, as component malalignment can lead to increased failure......Background - Surgeon-dependent factors such as optimal implant alignment are thought to play a significant role in outcome following primary total knee arthroplasty (TKA). Exact definitions and references for optimal alignment are, however, still being debated. This overview of the literature...... describes different definitions of component alignment following primary TKA for (1) tibiofemoral alignment in the AP plane, (2) tibial and femoral component placement in the AP plane, (3) tibial and femoral component placement in the sagittal plane, and (4) rotational alignment of tibial and femoral...

  2. Effect of lateral release and tibial tuberosity transposition on the patellar tilt analyzed by MRI

    Koskinen, S.; Kormano, M.; Kujala, U.M.; Research Institute for Sports and Exercise Medicine, Helsinki; City Hospital, Turku

    1990-01-01

    The preliminary results are presented from studies in which MRI techniques are used to analyze the effect of lateral release and tibial tuberosity transposition procedures on the patellofemoral relationships. (author). 4 refs.; 1 fig.; 1 tab

  3. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter.

    Al Kaissi, Ali; Ganger, Rudolf; Klaushofer, Klaus; Grill, Franz

    2014-01-01

    Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD) inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  4. Quantitative Comparison of the Microscopic Anatomy of the Human ACL Femoral and Tibial Entheses

    Beaulieu, Mélanie L.; Carey, Grace E.; Schlecht, Stephen H.; Wojtys, Edward M.; Ashton-Miller, James A.

    2015-01-01

    The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p fibrocartilage tissue area (p fibrocartilage depth (p fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. PMID:26134706

  5. Management of tibial fractures using a circular external fixator in two calves.

    Aithal, Hari Prasad; Kinjavdekar, Prakash; Amarpal; Pawde, Abhijit Motiram; Singh, Gaj Raj; Setia, Harish Chandra

    2010-07-01

    To report the repair of tibial diaphyseal fractures in 2 calves using a circular external skeletal fixator (CEF). Clinical report. Crossbred calves (n=2; age: 6 months; weight: 55 and 60 kg). Mid-diaphyseal tibial fractures were repaired by the use of a 4-ring CEF (made of aluminum rings with 2 mm K-wires) alone in 1 calf and in combination with hemicerclage wiring in 1 calf. Both calves had good weight bearing with moderate lameness postoperatively. Fracture healing occurred by day 60 in 1 calf and by day 30 in calf 2. The CEF was well maintained and tolerated by both calves through fracture healing. Joint mobility and limb usage improved gradually after CEF removal. CEF provided a stable fixation of tibial fractures and healing within 60 days and functional recovery within 90 days. CEF can be safely and successfully used for the management of selected tibial fractures in calves.

  6. Robotic assisted radical prostatectomy accelerates postoperative stress recovery: Final results of a contemporary prospective study assessing pathophysiology of cortisol peri-operative kinetics in prostate cancer surgery

    Antonio B. Porcaro

    2016-04-01

    Conclusion: Our study shows that PCa surgery immediately (POD 0 triggers the stress system which respond by overproduction of cortisol which induces the negative feedback mechanism that starts on POD 1, is still ongoing on POD 5, but is completely settled on POD 45. Moreover, after surgical trauma, our study gives evidence that the RARP procedure associates with stress recovery faster than RRP. Further confirmatory studies are required.

  7. Accelerator microanalysis

    Tuniz, C.

    1997-01-01

    Particle accelerators have been developed more than sixty years ago to investigate nuclear and atomic phenomena. A major shift toward applications of accelerators in the study of materials structure and composition in inter-disciplinary projects has been witnessed in the last two decades. The Australian Nuclear Science and Technology Organisation (ANSTO) has developed advanced research programs based on the use of particle and photon beams. Atmospheric pollution problems are investigated at the 3 MV Van de Graff accelerator using ion beam analysis techniques to detect toxic elements in aerosol particles. High temperature superconductor and semiconductor materials are characterised using the recoil of iodine and other heavy ions produced at ANTARES, the 10-MV Tandem accelerator. A heavy-ion microprobe is presently being developed at ANTARES to map elemental concentrations of specific elements with micro-size resolution. An Accelerator mass Spectrometry (AMS) system has been developed at ANSTO for the ultra-sensitive detection of Carbon-14, Iodine-129 and other long-lived radioisotopes. This AMS spectrometer is a key instrument for climate change studies and international safeguards. ANSTO is also managing the Australian Synchrotron Research program based on facilities developed at the Photon Factory (Japan) and at the Advanced Photon Source (USA). Advanced projects in biology, materials chemistry, structural condensed matter and other disciplines are being promoted by a consortium involving Australian universities and research institutions. This paper will review recent advances in the use of particle accelerators, with a particular emphasis on applications developed at ANSTO and related to problems of international concern, such as global environmental change, public health and nuclear proliferation

  8. Effect of Icariin on Tibial Dyschondroplasia Incidence and Tibial Characteristics by Regulating P2RX7 in Chickens

    Hui Zhang

    2018-01-01

    Full Text Available Tibial dyschondroplasia (TD is a disease of rapid growing chickens that occurs in many avian species; it is characterized by nonvascular and nonmineralized growth plates, along with tibia bone deformation and lameness. Icariin is widely used to treat bone diseases in humans, but no report is available regarding the effectiveness of icariin against avian TD. Therefore, this study was designed to determine its effect against TD. For this purpose, a total of 180 broiler chicks were distributed into three groups including control, TD, and icariin group. Control group was given a standard normal diet, while TD and icariin groups received normal standard diet containing 50 mg/kg thiram to induce TD from days 3 to 7 after hatch. After the induction of TD, the chicks of icariin group were fed with standard normal diet by adding 10 mg/kg icariin in water. Then morphological and production parameters analysis of tibial bone indicators, physiological index changes, and gene expression were examined. The results showed that icariin administration not only decreased the mortality but also mitigated the lameness and promoted the angiogenesis, which diminished the TD lesion and significantly increased the expression of P2RX7 (P<0.05 in TD affected thiram induced chicks. In conclusion, present findings suggest that icariin has a significant role in promoting the recovery of chicken growth plates affected by TD via regulating the P2RX7. Our findings reveal a new target for clinical treatment and prevention of TD in broiler chickens.

  9. Comparison of long-term results between osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

    Charoenrook, Victor; Michael, Ralph; de la Paz, Maria Fideliz; Temprano, José; Barraquer, Rafael I

    2018-04-01

    To compare the anatomical and the functional results between osteo-odonto-keratoprosthesis (OOKP) and keratoprosthesis using tibial bone autograft (Tibial bone KPro). We reviewed the charts of 258 patients; 145 had OOKP whereas 113 had Tibial bone KPro implanted. Functional success was defined as best corrected visual acuity ≥0.05 on decimal scale and anatomical success as retention of the keratoprosthesis lamina. Kaplan-Meier survival curves were calculated for anatomical and functional survival as well as to estimate the probability of post-op complications. The anatomical survival for both KPro groups was not significantly different and was estimated as 67% for OOKP and 54% for Tibial bone KPro at 10 years after surgery. There was also no difference found after subdividing for primary diagnosis groups such as chemical injury, thermal burn, trachoma and all autoimmune cases combined. Estimated functional survival at 10 years post-surgery was 49% for OOKP and 25% for Tibial bone KPro, which was significantly different. The probability of patients with Tibial bone KPro developing one or more post-operative complications at 10 years after surgery (65%) was significantly higher than those with OOKP (40%). Mucous membrane necrosis and retroprosthetic membrane formation were more common in Tibial bone KPro than OOKP. Both types of autologous biological KPro, OOKP and Tibial bone KPro, had statistically similar rate of keratoprosthesis extrusion. Although functional success rate was significantly higher in OOKP, it may have been influenced by a better visual potential in the patients in this group. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-06-01

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

  11. SIMULTANEOUS BILATERAL AVULSION FRACTURE OF THE TIBIAL TUBEROSITY IN A TEENAGER: CASE REPORT AND THERAPY USED.

    E Albuquerque, Rodrigo Pires; Giordano, Vincenzo; Carvalho, Antônio Carlos Pires; Puell, Thiago; E Albuquerque, Maria Isabel Pires; do Amaral, Ney Pecegueiro

    2012-01-01

    Simultaneous bilateral avulsion fracture of the tibial tuberosity in teenagers is a rare lesion. We describe the first case in the literature, in a teenage girl who sustained a fall while jumping during a volleyball match. No predisposing factors were iden tified. The lesions were treated with open surgical reduction and internal fixation. The aim of the present study was to present a case of simultaneous bilateral avulsion fracture of the tibial tuberosity in a teenage girl and the therapy used.

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

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

    2017-01-01

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

  13. Locking plate fixation in distal metaphyseal tibial fractures: series of 79 patients

    Gupta, Rakesh K.; Rohilla, Rajesh Kumar; Sangwan, Kapil; Singh, Vijendra; Walia, Saurav

    2009-01-01

    Open reduction and internal fixation in distal tibial fractures jeopardises fracture fragment vascularity and often results in soft tissue complications. Minimally invasive osteosynthesis, if possible, offers the best possible option as it permits adequate fixation in a biological manner. Seventy-nine consecutive adult patients with distal tibial fractures, including one patient with a bilateral fracture of the distal tibia, treated with locking plates, were retrospectively reviewed. The 4.5-...

  14. Complex Medial Meniscus Tears Are Associated With a Biconcave Medial Tibial Plateau.

    Barber, F Alan; Getelman, Mark H; Berry, Kathy L

    2017-04-01

    To determine whether an association exists between a biconcave medial tibial plateau and complex medial meniscus tears. A consecutive series of stable knees undergoing arthroscopy were evaluated retrospectively with the use of preoperative magnetic resonance imaging (MRI), radiographs, and arthroscopy documented by intraoperative videos. Investigators independently performed blinded reviews of the MRI or videos. Based on the arthroscopy findings, medial tibial plateaus were classified as either biconcave or not biconcave. A transverse coronal plane ridge, separating the front of the tibial plateau from the back near the inner margin of the posterior body of the medial meniscus, was defined as biconcave. The medial plateau slope was calculated with MRI sagittal views. General demographic information, body mass index, and arthroscopically confirmed knee pathology were recorded. A total of 179 consecutive knees were studied from July 2014 through August 2015; 49 (27.2%) biconcave medial tibial plateaus and 130 (72.8%) controls were identified at arthroscopy. Complex medial meniscus tears were found in 103. Patients with a biconcave medial tibial plateau were found to have more complex medial meniscus tears (69.4%) than those without a biconcavity (53.1%) (P = .049) despite having lower body mass index (P = .020). No difference in medial tibial plateau slope was observed for biconcavities involving both cartilage and bone, bone only, or an indeterminate group (P = .47). Biconcave medial tibial plateaus were present in 27.4% of a consecutive series of patients undergoing knee arthroscopy. A biconcave medial tibial plateau was more frequently associated with a complex medial meniscus tear. Level III, case-control study. Copyright © 2016 Arthroscopy Association of North America. All rights reserved.

  15. Passive Posterior Tibial Subluxation on Routine Knee MRI as a Secondary Sign of PCL Tear

    Degnan, A.J.; Adam, R.J.; Maldjian, C.; Harner, Ch.D.

    2014-01-01

    The posterior drawer test is an accurate clinical test to diagnose posterior cruciate ligament (PCL), indicating laxity of the PCL that allows posterior tibial translation. This study aimed to determine whether posterior tibial translation relative to the femur on routine MRI could serve as an additional sign of PCL tear. Routine knee MRI in eleven patients (7 males, 4 females) with arthroscopically confirmed isolated PCL tears were reviewed independently by two musculoskeletal radiologists. Measurements of tibial translation were made in the medial and lateral compartments of patients and controls (10 males, 12 females) without clinical or MRI evidence of ligament injury. Significant medial compartment posterior tibial translation was present in patients with PCL tear compared to controls (+2.93 mm versus +0.03 mm, Ρ=0.002) with excellent interobserver agreement (intraclass correlation coefficient (ICC) = 0.94). No significant difference in lateral compartment tibial translation was observed (+0.17 mm versus -0.57 mm, Ρ=0.366) despite excellent interobserver agreement (ICC = 0.96). Posterior tibial translation in the midmedial compartment may be a secondary sign of isolated PCL tear on routine knee MRI with passive extension without manipulation or weight bearing. Additional work in a larger cohort may better address the accuracy of this finding

  16. Local and Widespread Hyperalgesia After Isolated Tibial Shaft Fractures Treated with Intramedullary Nailing

    Larsen, Peter; Elsøe, Rasmus; Graven-Nielsen, Thomas

    2016-01-01

    OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months postopera...... fracture treated with intramedullary nailing, although no widespread (extrasegmental) hyperalgesia was detected. Such observations may be important for developing the most adequate rehabilitation procedure following a tibial fracture.......OBJECTIVES: Knee pain is accepted as a common complication to intramedullary nailing of tibial fractures. However, no studies have systematically studied the pain sequel following tibial fractures. The objective of this study was to assess pain and hyperalgesia from 6 weeks to 12 months...... postoperatively after intramedullary nailing of tibial shaft fracture. METHODS: A total of 39 patients were included in this 12-month follow-up study. After 6 weeks, 3, 6, and 12 months postoperatively the pain intensity was measured on a visual analog scale (VAS) and the pressure pain sensitivity was assessed...

  17. Locking internal fixator with minimally invasive plate osteosynthesis for the proximal and distal tibial fractures

    TONG Da-ke

    2012-02-01

    Full Text Available 【Abstract】Objective: To investigate the efficacy of the locking internal fixator (LIF, which includes the locking compression plate (LCP and the less invasive stable system (LISS, in the proximal and distal tibial fractures. Methods: We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the opera- tion with LIF by the minimally invasive plate osteosynthesis (MIPO technique. The data consisted of 43 proximal tibial fractures (type AO41C3 and 55 distal tibial fractures (type AO43C3. Results: No complications were observed in all patients after operation. The mean healing time was 8.4 months (range 5-14 months. Only two cases of delayed union occurred at postoperative 10 months. No infections were reported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at postoperative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion: Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing. Key words: Internal fixator; Tibial fractures; Fracture fixation, intramedullary; Bone plates

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

    Sari, Murat; Tuna, Can; Akogul, Serkan

    2018-03-28

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

  19. Accelerator operations

    Anon.

    1980-01-01

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  20. CNSTN Accelerator

    Habbassi, Afifa; Trabelsi, Adel

    2010-01-01

    This project give a big idea about the measurement of the linear accelerator in the CNSTN. During this work we control dose distribution for different product. For this characterisation we have to make an installation qualification ,operational qualification,performance qualification and of course for every step we have to control temperature and the dose ,even the distribution of the last one.

  1. Accelerators course

    CERN. Geneva HR-RFA; Métral, E

    2006-01-01

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges

  2. Accelerator operations

    Anon.

    1979-01-01

    Operations of the SuperHILAC, the Bevatron/Bevalac, and the 184-inch Synchrocyclotron during the period from October 1977 to September 1978 are discussed. These include ion source development, accelerator facilities, the Heavy Ion Spectrometer System, and Bevelac biomedical operations

  3. Accelerator update

    Anon.

    1995-01-01

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS

  4. Accelerator update

    Anon.

    1995-09-15

    When the Accelerator Conference, combined International High Energy and US Particle versions, held in Dallas in May, was initially scheduled, progress nearby for the US Superconducting Supercollider was high on the preliminary agenda. With the SSC voted down by Congress in October 1993, this was no longer the case. However the content of the meeting, in terms of both its deep implications for ambitious new projects and the breadth of its scope, showed that the worldwide particle accelerator field is far from being moribund. A traditional feature of such accelerator conferences is the multiplicity of parallel sessions. No one person can attend all sessions, so that delegates can follow completely different paths and emerge with totally different impressions. Despite this overload, and despite the SSC cancellation, the general picture is one of encouraging progress over a wide range of major new projects throughout the world. At the same time, spinoff from, and applications of, accelerators and accelerator technology are becoming increasingly important. Centrestage is now CERN's LHC proton-proton collider, where a test string of superconducting magnets is operating over long periods at the nominal LHC field of 8.36 tesla or more. The assignment of the underground areas in the existing 27- kilometre LEP tunnel is now quasidefinitive (see page 3). For CERN's existing big machine, the LEP electron-positron collider, ongoing work concentrates on boosting performance using improved optics and bunch trains. But the main objective is the LEP2 scheme using superconducting accelerating cavities to boost the beam energy (see page 6). After some initial teething problems, production and operation of these cavities appears to have been mastered, at least under test conditions. A highlight at CERN last year was the first run with lead ions (December 1994, page 15). Handling these heavy particles with systems originally designed for protons calls for ingenuity. The SPS has managed

  5. [The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement].

    García David, S; Cortijo Martínez, J A; Navarro Bermúdez, I; Maculé, F; Hinarejos, P; Puig-Verdié, L; Monllau, J C; Hernández Hermoso, J A

    2014-01-01

    The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

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

    Anand Ajmera

    2015-01-01

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

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

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

    2015-01-01

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

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

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

    2011-10-01

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

  9. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    and developing the best business ideas and support the due diligence process. Even universities are noticing that the learning experience of the action learning approach is an effective way to develop capabilities and change cultures. Accelerators related to what has historically been associated...

  10. Qualidade fisiológica de sementes de camomila [Chamomilla recutita (L. Rauschert] após envelhecimento acelerado e estresse salino Physiological quality of chamomile [Chamomilla recutita (L. Rauschert] seeds after accelerated aging and salt stress

    D.G Rollwagen

    2011-01-01

    Full Text Available O objetivo do trabalho foi verificar a qualidade fisiológica de sementes da camomila submetidas a diferentes tempos de envelhecimento acelerado e ao estresse salino. Os experimentos foram realizados no Laboratório de Técnica de Sementes na PUCPR em São José dos Pinhais, Paraná. Os tempos de envelhecimento acelerado foram de 0, 24, 48, 72 e 96 h e o estresse salino foi induzido por soluções de cloreto de sódio com potenciais osmóticos de 0; -0,2; -0,4; -0,6; -0,8; -1,0 MPa, ambos com quatro repetições. Foram avaliados a germinação, o índice de velocidade de germinação (IVG, o tempo médio de germinação (TMG, a velocidade media de germinação (VMG e a entropia. O delineamento experimental adotado foi o de blocos casualizados . Concluiu-se que as sementes de camomila tiveram sua qualidade fisiológica afetada após 24h de envelhecimento acelerado e sob estresse salino causado por solução de potencial osmótico de -0,6 MPaThe aim of this study was to verify the physiological quality of chamomile seeds subjected to different accelerated aging periods and salt stress. The experiments were carried out in the Laboratory of Seed Technique, PUCPR, São José dos Pinhais, Paraná State, Brazil. The accelerated aging periods were 0, 24, 48, 72 and 96 h and the salt stress was induced by sodium chloride solutions with osmotic potentials of 0, -0.2, -0.4, -0.6, -0.8, -1.0 MPa, both with four replicates. The analyzed variables were: germination, germination velocity index (GVI, average germination time (AGT, average germination velocity (AGV and entropy. Experimental design was in randomized blocks. Chamomile seeds had their physiological quality affected after 24 h of accelerated aging and under salt stress caused by the solution with osmotic potential of -0.6 MPa

  11. Computed tomography of stress fracture

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-01-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic. (orig.)

  12. Computed tomography of stress fracture

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-01-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic

  13. Variation in tibial functionality and fracture susceptibility among healthy, young adults arises from the acquisition of biologically distinct sets of traits.

    Jepsen, Karl J; Evans, Rachel; Negus, Charles H; Gagnier, Joel J; Centi, Amanda; Erlich, Tomer; Hadid, Amir; Yanovich, Ran; Moran, Daniel S

    2013-06-01

    Physiological systems like bone respond to many genetic and environmental factors by adjusting traits in a highly coordinated, compensatory manner to establish organ-level function. To be mechanically functional, a bone should be sufficiently stiff and strong to support physiological loads. Factors impairing this process are expected to compromise strength and increase fracture risk. We tested the hypotheses that individuals with reduced stiffness relative to body size will show an increased risk of fracturing and that reduced strength arises from the acquisition of biologically distinct sets of traits (ie, different combinations of morphological and tissue-level mechanical properties). We assessed tibial functionality retrospectively for 336 young adult women and men engaged in military training, and calculated robustness (total area/bone length), cortical area (Ct.Ar), and tissue-mineral density (TMD). These three traits explained 69% to 72% of the variation in tibial stiffness (p stress fracture based on radiography and scintigraphy. K-means cluster analysis was used to segregate men and women into subgroups based on robustness, Ct.Ar, and TMD adjusted for body size. Stiffness varied 37% to 42% among the clusters (p stress fracture cases segregated to three clusters (p fracture risk. Our results have important implications for developing personalized preventative diagnostics and treatments. Copyright © 2013 American Society for Bone and Mineral Research.

  14. Laser acceleration

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  15. Laser acceleration

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-01-01

    The fundamental idea of LaserWakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wake fields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ∼ c and ultra fastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nano materials is also emerging.

  16. Accelerating networks

    Smith, David M D; Onnela, Jukka-Pekka; Johnson, Neil F

    2007-01-01

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  17. Effect of cranial cruciate ligament deficiency, tibial plateau leveling osteotomy, and tibial tuberosity advancement on contact mechanics and alignment of the stifle in flexion.

    Kim, Stanley E; Pozzi, Antonio; Banks, Scott A; Conrad, Bryan P; Lewis, Daniel D

    2010-04-01

    To assess contact mechanics and 3-dimensional (3-D) joint alignment in cranial cruciate ligament (CCL)-deficient stifles before and after tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA) with the stifle in 90 degrees of flexion. In vitro biomechanical study. Cadaveric pelvic limb pairs (n=8) from dogs weighing 28-35 kg. Contralateral limbs were assigned to receive TPLO or TTA. Digital pressure sensors were used to measure femorotibial contact area, peak and mean contact pressure, and peak pressure location with the limb under a load of 30% body weight and stifle flexion angle of 90 degrees . 3-D poses were obtained using a Microscribe digitizer. Specimens were tested under normal, CCL deficient, and treatment conditions. Significant disturbances in alignment were not observed after CCL transection, although medial contact area was 10% smaller than normal (P=.003). There were no significant differences in contact mechanics or alignment between normal and TTA conditions; TPLO induced 6 degrees varus angulation (PCranial tibial subluxation is nominal in CCL-deficient stifles loaded in flexion. Stifle alignment and contact mechanics are not altered by TTA, whereas TPLO causes mild varus and a subsequent increase in medial compartment loading. Cranial tibial subluxation of CCL-deficient stifles may not occur during postures that load the stifle in flexion. The significance of minor changes in loading patterns after TPLO is unknown.

  18. Delay in weight bearing in surgically treated tibial shaft fractures is associated with impaired healing: a cohort analysis of 166 tibial fractures.

    Houben, I B; Raaben, M; Van Basten Batenburg, M; Blokhuis, T J

    2018-04-09

    The relation between timing of weight bearing after a fracture and the healing outcome is yet to be established, thereby limiting the implementation of a possibly beneficial effect for our patients. The current study was undertaken to determine the effect of timing of weight bearing after a surgically treated tibial shaft fracture. Surgically treated diaphyseal tibial fractures were retrospectively studied between 2007 and 2015. The timing of initial weight bearing (IWB) was analysed as a predictor for impaired healing in a multivariate regression. Totally, 166 diaphyseal tibial fractures were included, 86 cases with impaired healing and 80 with normal healing. The mean age was 38.7 years (range 16-89). The mean time until IWB was significantly shorter in the normal fracture healing group (2.6 vs 7.4 weeks, p bearing is independently associated with impaired fracture healing in surgically treated tibial shaft fractures. Unlike other factors such as fracture type or soft tissue condition, early resumption of weight bearing can be influenced by the treating physician and this factor therefore has a direct clinical relevance. This study indicates that early resumption of weight bearing should be the treatment goal in fracture fixation. 3b.

  19. Induced membrane technique combined with two-stage internal fixation for the treatment of tibial osteomyelitis defects.

    Luo, Fei; Wang, Xiaohua; Wang, Shulin; Fu, Jingshu; Xie, Zhao

    2017-07-01

    The purpose of this study was to observe the effects of induced membrane technique combined with two-stage internal fixation in the treatment of tibial osteomyelitis defects. A retrospective analyses for 67 cases of tibialosteomyelitis defects were admitted to our department between September 2012 to February 2015, which were treated with induced membrane technique. At the first stage, implanted with a PMMA cement spacer in the defects after radical debridement and fixed with reconstructive locked plate. Bone grafting and exchanged the plate with intramedullary nail at the second stage. In current study, all patients were followed up for 18-35 months. Sixty-six patients achieved bone union with the average radiographic and clinical healing times of 5.55±2.19 and 7.45±1.69months, respectively. Seven patients required a second debridement before grafting, while four patients experienced a recurrence of infection or a relapse following second stage treatment. Twelve patients experienced either knee or ankle dysfunctions and 2 patients faced delayed wound healing. Donor site complications includes pain and infection were found in 7 and 3 patients, respectively with delayed stress fracture in 1 patient only. Induced membrane technique for the treatment of tibial osteomyelitis defects, seems a reliable method. The use of reconstructive locked plate as a temporary internal fixation at the first stage and exchanged with intramedullary nail at the second stage, potentially achieves good clinical efficacy. Care should be taken to restore the joint function especially in distal tibia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effects of diabetic peripheral neuropathy on gait in vascular trans-tibial amputees.

    Nakajima, Hiroshi; Yamamoto, Sumiko; Katsuhira, Junji

    2018-07-01

    Patients with diabetes often develop diabetic peripheral neuropathy, which is a distal symmetric polyneuropathy, so foot function on the non-amputated side is expected to affect gait in vascular trans-tibial amputees. However, there is little information on the kinematics and kinetics of gait or the effects of diabetic peripheral neuropathy in vascular trans-tibial amputees. This study aimed to clarify these effects, including the biomechanics of the ankle on the non-amputated side. Participants were 10 vascular trans-tibial amputees with diabetic peripheral neuropathy (group V) and 8 traumatic trans-tibial amputees (group T). Each subject's gait was analyzed at a self-selected speed using a three-dimensional motion analyzer and force plates. Ankle plantarflexion angle, heel elevation angle, and peak and impulse of anterior ground reaction force were smaller on the non-amputated side during pre-swing in group V than in group T. Center of gravity during pre-swing on the non-amputated side was lower in group V than in group T. Hip extension torque during loading response on the prosthetic side was greater in group V than in group T. These findings suggest that the biomechanical function of the ankle on the non-amputated side during pre-swing is poorer in vascular trans-tibial amputees with DPN than in traumatic trans-tibial amputees; the height of the center of gravity could not be maintained during this phase in vascular trans-tibial amputees with diabetic peripheral neuropathy. The hip joint on the prosthetic side compensated for this diminished function at the ankle during loading response. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Repeated Stress Fractures in an Amenorrheic Marathoner: A Case Conference.

    Sutton, John R.; Nilson, Karen L.

    1989-01-01

    Presents a case conference by 2 experts on the relationship between a 26-year-old marathoner's amenorrhea and her sustained unusual stress fractures in 4 ribs (plus previous similar fractures of the calcaneal, navicular, metatarsal, and tibial bones). The experts conclude that she suffers many manifestations of overtraining. (SM)

  2. Posterior tibial tendon insufficiency results at different stages.

    Deland, Jonathan T; Page, Alexandra; Sung, Il-Hoon; O'Malley, Martin J; Inda, David; Choung, Steven

    2006-09-01

    The results of surgical treatment of posterior tibial tendon insufficiency (PTTI) may be different at different stages of the disease. No single study has compared the results at different stages. This comparison can be helpful to the patient and physician if the patient asks "What if I wait and the disease progresses, how will my results be different?" A preliminary study comparing results for stage IIa, stage IIb (advanced stage II), and stage III was performed followed by a larger study comparing IIa and IIb with 26 and 22 patients, respectively. American Orthopaedic Foot and Ankle Society (AOFAS) outcome scores as well as radiographs and functional questions were used. Nearly all patients, regardless of stage, felt they were helped by surgical treatment. However, the lowest AOFAS score was in stage III, the most advanced stage investigated in this study. In comparing stage IIa and IIb patients, stage IIb patients had a statistically higher incidence of lateral discomfort. Although statistically significant differences were not found in all comparisons, this study suggests that the results of surgical treatment for PTTI declines with increasing stage or severity of disease.

  3. Bilateral Posterior Tibial Tendon and Flexor Digitorum Longus Dislocations.

    Padegimas, Eric M; Beck, David M; Pedowitz, David I

    2017-04-01

    The authors present a case of a previously healthy and athletic 17-year-old female who presented with a 3.5-year history of medial left ankle pain after sustaining an inversion injury while playing basketball. Prior to presentation, she had failed prior immobilization and physical therapy for a presumed ankles sprain. Physical examination revealed a dislocated posterior tibial tendon (PTT) that was temporarily reducible, but would spontaneously dislocate immediately after reduction. She had pain and snapping of the PTT with resisted ankle plantar flexion and resisted inversion as well as 4/5 strength in ankle inversion. The diagnosis of dislocated PTT was confirmed on magnetic resonance imaging (MRI). The patient underwent suture anchor repair of the medial retinaculum of the left ankle. At the time of surgery both the PTT and flexor digitorum longus (FDL) were dislocated. Three months postoperatively, the patient represented with PTT dislocation of the right (nonoperative) ankle confirmed by MRI. After failure of immobilization, physical therapy, and oral anti-inflammatory medications, the patient underwent suture anchor repair of the medial retinaculum of the right ankle. At 6 months postoperatively, the patient has 5/5 strength inversion bilaterally, no subluxation of either PTT, and has returned to all activities without limitation. The authors present this unique case of bilateral PTT dislocation and concurrent PTT/FDL dislocation along with review of the literature for PTT dislocation. The authors highlight the common misdaiganosis of this injury and highlight the successful results of surgical intervention. Level V: Case report.

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

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

    2016-03-01

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

  5. Comparison of Different Approaches for Measuring Tibial Cartilage Thickness

    Maier Jennifer

    2017-07-01

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

  6. Stress changes of lateral collateral ligament at different

    ZHONG Yan-lin

    2011-04-01

    Full Text Available 【Abstract】 Objective: To create a 3-dimensional finite element model of knee ligaments and to analyse the stress changes of lateral collateral ligament (LCL with or without displaced movements at different knee flexion conditions. Methods: A four-major-ligament contained knee specimen from an adult died of skull injury was prepared for CT scanning with the detectable ligament insertion footprints, locations and orientations precisely marked in advance. The CT scanning images were converted to a 3-dimensional model of the knee with the 3-dimensional reconstruction technique and transformed into finite element model by the software of ANSYS. The model was validated using experimental and numerical results obtained by other scientists. The natural stress changes of LCL at five different knee flexion angles (0°, 30°, 60°, 90°, 120° and under various motions of anterior-posterior tibial translation, tibial varus rotation and internal-external tibial rotation were measured. Results: The maximum stress reached to 87%-113% versus natural stress in varus motion at early 30° of knee flexions. The stress values were smaller than the peak value of natural stress at 0° (knee full extension when knee bending was over 60° of flexion in anterior-posterior tibial translation and internal-external rotation. Conclusion: LCL is vulnerable to varus motion in almost all knee bending positions and susceptible to anterior- posterior tibial translation or internal-external rotation at early 30° of knee flexions. Key words: Knee joint; Collateral ligaments; Finite element analysis

  7. Advanced concepts for acceleration

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations

  8. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  9. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-01-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process

  10. Sequential avulsions of the tibial tubercle in an adolescent basketball player.

    Huang, Ying Chieh; Chao, Ying-Hao; Lien, Fang-Chieh

    2010-05-01

    Tibial tubercle avulsion is an uncommon fracture in physically active adolescents. Sequential avulsion of tibial tubercles is extremely rare. We reported a healthy, active 15-year-old boy who suffered from left tibial tubercle avulsion fracture during a basketball game. He received open reduction and internal fixation with two smooth Kirschner wires and a cannulated screw, with every effort to reduce the plate injury. Long-leg splint was used for protection followed by programmed rehabilitation. He recovered uneventfully and returned to his previous level of activity soon. Another avulsion fracture happened at the right tibial tubercle 3.5 months later when he was playing the basketball. From the encouragement of previous successful treatment, we provided him open reduction and fixation with two small-caliber screws. He recovered uneventfully and returned to his previous level of activity soon. No genu recurvatum or other deformity was happening in our case at the end of 2-year follow-up. No evidence of Osgood-Schlatter disease or osteogenesis imperfecta was found. Sequential avulsion fractures of tibial tubercles are rare. Good functional recovery can often be obtained like our case if we treat it well. To a physically active adolescent, we should never overstate the risk of sequential avulsion of the other leg to postpone the return to an active, functional life.

  11. CT determination of tibial tubercle lateralization in patients presenting with anterior knee pain

    Jones, R.B. [Dept. of Physiology, School of Medicine, East Carolina Univ., Greenville, NC (United States); Bartlett, E.C. [Dept. of Surgery, School of Medicine, East Carolina Univ., Greenville, NC (United States); Vainright, J.R. [Dept. of Radiology, School of Medicine, East Carolina Univ., Greenville, NC (United States); Carrol, R.G. [Dept. of Physiology, School of Medicine, East Carolina Univ., Greenville, NC (United States)

    1995-10-01

    Using CT imaging with computerized technique to measure anatomic relationships, we evaluated patients (n = 50) with anterior knee pain for excessive lateralization of the tibial tubercle. The symptomatic knee of each patient was compared with their asymptomatic knee as well as with the knees of patients with other causes of anterior knee pain (n = 10) and with the knees of asymptomatic controls (n = 10). The symptomatic knee of patients with suspected patellofemoral malalignment demonstrated significantly greater lateralization of the tibial tubercle (12.2 {+-} 0.5 mm) than did the asymptomatic knee (9.0 {+-} 0.7 mm). The symptomatic knees of patients with patellofemoral malalignment also demonstrated significantly greater lateralization of the tibial tubercle than did the knees of patients with other causes of anterior knee pain (5.9 {+-} 0.9 mm). When a control population was added to the analysis, the patients with symptomatic patellofemoral malalignment demonstrated significantly greater lateralization of the tibial tubercle than did the controls (6.4 {+-} 0.4 mm). Using a critical value of 9 mm lateralization, the CT diagnosis of patellofemoral malalignment had a specificity of 95% and a sensitivity of 85%. We conclude that CT determination of tibial tubercle position assists the diagnosis of patellofemoral malalignment. (orig./MG)

  12. Increasing lateral tibial slope: is there an association with articular cartilage changes in the knee?

    Khan, Nasir; Shepel, Michael; Leswick, David A.; Obaid, Haron

    2014-01-01

    The geometry of the lateral tibial slope (LTS) plays an important role in the overall biomechanics of the knee. Through this study, we aim to assess the impact of LTS on cartilage degeneration in the knee. A retrospective analysis of 93 knee MRI scans (1.5 T or 3 T) for patients aged 20-45 years with no history of trauma or knee surgery, and absence of internal derangement. The LTS was calculated using the circle method. Chondropathy was graded from 0 (normal) to 3 (severe). Linear regression analysis was used for statistical analysis (p < 0.05). In our cohort of patients, a statistically significant association was seen between increasing LTS and worsening cartilage degenerative changes in the medial patellar articular surface and the lateral tibial articular surface (p < 0.05). There was no statistically significant association between increasing LTS and worsening chondropathy of the lateral patellar, medial trochlea, lateral trochlea, medial femoral, lateral femoral, and medial tibial articular surfaces. Our results show a statistically significant association between increasing LTS and worsening cartilage degenerative changes in the medial patella and the lateral tibial plateau. We speculate that increased LTS may result in increased femoral glide over the lateral tibial plateau with subsequent increased external rotation of the femur predisposing to patellofemoral articular changes. Future arthroscopic studies are needed to further confirm our findings. (orig.)

  13. Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

    Schwartz, Adam J; Ravi, Bheeshma; Kransdorf, Mark J; Clarke, Henry D

    2017-07-01

    A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Increasing lateral tibial slope: is there an association with articular cartilage changes in the knee?

    Khan, Nasir; Shepel, Michael; Leswick, David A.; Obaid, Haron [University of Saskatchewan, Department of Medical Imaging, Royal University Hospital, and College of Medicine, Saskatoon, Saskatchewan (Canada)

    2014-04-15

    The geometry of the lateral tibial slope (LTS) plays an important role in the overall biomechanics of the knee. Through this study, we aim to assess the impact of LTS on cartilage degeneration in the knee. A retrospective analysis of 93 knee MRI scans (1.5 T or 3 T) for patients aged 20-45 years with no history of trauma or knee surgery, and absence of internal derangement. The LTS was calculated using the circle method. Chondropathy was graded from 0 (normal) to 3 (severe). Linear regression analysis was used for statistical analysis (p < 0.05). In our cohort of patients, a statistically significant association was seen between increasing LTS and worsening cartilage degenerative changes in the medial patellar articular surface and the lateral tibial articular surface (p < 0.05). There was no statistically significant association between increasing LTS and worsening chondropathy of the lateral patellar, medial trochlea, lateral trochlea, medial femoral, lateral femoral, and medial tibial articular surfaces. Our results show a statistically significant association between increasing LTS and worsening cartilage degenerative changes in the medial patella and the lateral tibial plateau. We speculate that increased LTS may result in increased femoral glide over the lateral tibial plateau with subsequent increased external rotation of the femur predisposing to patellofemoral articular changes. Future arthroscopic studies are needed to further confirm our findings. (orig.)

  15. CT determination of tibial tubercle lateralization in patients presenting with anterior knee pain

    Jones, R.B.; Bartlett, E.C.; Vainright, J.R.; Carrol, R.G.

    1995-01-01

    Using CT imaging with computerized technique to measure anatomic relationships, we evaluated patients (n = 50) with anterior knee pain for excessive lateralization of the tibial tubercle. The symptomatic knee of each patient was compared with their asymptomatic knee as well as with the knees of patients with other causes of anterior knee pain (n = 10) and with the knees of asymptomatic controls (n = 10). The symptomatic knee of patients with suspected patellofemoral malalignment demonstrated significantly greater lateralization of the tibial tubercle (12.2 ± 0.5 mm) than did the asymptomatic knee (9.0 ± 0.7 mm). The symptomatic knees of patients with patellofemoral malalignment also demonstrated significantly greater lateralization of the tibial tubercle than did the knees of patients with other causes of anterior knee pain (5.9 ± 0.9 mm). When a control population was added to the analysis, the patients with symptomatic patellofemoral malalignment demonstrated significantly greater lateralization of the tibial tubercle than did the controls (6.4 ± 0.4 mm). Using a critical value of 9 mm lateralization, the CT diagnosis of patellofemoral malalignment had a specificity of 95% and a sensitivity of 85%. We conclude that CT determination of tibial tubercle position assists the diagnosis of patellofemoral malalignment. (orig./MG)

  16. Ring accelerators

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  17. accelerating cavity

    On the inside of the cavity there is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  18. Untangling metabolic and spatial interactions of stress tolerance in plants. 2. Accelerated method for measuring and predicting stress tolerance. Can we unravel the mysteries of the interactions between photosynthesis and respiration?

    Biel, Karl Y; Nishio, John N

    2010-09-01

    A simple method using the O(2) electrode that allows examination of the response of respiration and photosynthesis in leaf slices or algae to anoxia and high light under different temperatures useful for the examination of the interactions among photosynthesis, photorespiration, and respiration is described. The method provides a quantifiable assessment of stress tolerance that also permits us to examine fundamental biochemically and genetically related responses involved in stress tolerance and the cooperation among organelles. Additionally, we demonstrated a role for compounds, such as NO(-)(3) and oxaloacetate, as protective agents against photoinhibition, and we examined the role of dark adaptation in the activation of photosynthesis and NO(-)(3)-dependent O(2) oxygen evolution. A physiological and ecological role of a dark period (night) in stress tolerance is presented. Utilizing the method to follow changes in such metabolic activities as protein synthesis, protein conformation states, enzymes activity, carbon metabolism, and gene expression at different points during the treatments will be educational.

  19. Cosmic ray acceleration mechanisms

    Cesarsky, C.J.

    1982-09-01

    We present a brief summary of some of the most popular theories of cosmic ray acceleration: Fermi acceleration, its application to acceleration by shocks in a scattering medium, and impulsive acceleration by relativistic shocks

  20. Higher tibial quantitative ultrasound in young female swimmers.

    Falk, B; Bronshtein, Z; Zigel, L; Constantini, N; Eliakim, A

    2004-08-01

    It has been found that swimming, a non-impact sport, generally has no effect on bone mineral density. To examine bone properties, as measured by quantitative ultrasound, among female swimmers in comparison with control girls and women. Subjects included 61 swimmers and 71 controls aged 8.5 to 26.5 years. None of the swimmers was at the elite level and none had included resistance training in her schedule. Bone speed of sound (SOS) was measured bilaterally at the distal radius and the mid-tibia. No differences were observed between swimmers and controls in body mass (mean (SD): 49.7 (12.3) v 50.7 (12.4) kg, respectively), although swimmers were taller (159 (12) v 155 (12) cm) and had lower body fat (18.3 (4.2)% v 22.3 (5.4)%). No difference was found in time since menarche (5.2 (4.0) and 4.5 (2.9) years in swimmers and controls, respectively; 21 swimmers and 25 control were premenarcheal). Radial speed of sound (SOS) increased with age but did not differ between swimmers and controls (non-dominant: 3904 (172) and 3889 (165) m/s for swimmers and controls, respectively). Tibial SOS also increased with age and was significantly higher in swimmers than in controls (non-dominant: 3774 (155) v 3712 (171) m/s). No differences were found between dominant and non-dominant sides. Swimming appears to be associated with higher bone SOS in the lower but not in the upper extremities. Further studies are needed to assess whether this difference reflects higher habitual activity among the swimmers or swimming specific mechanisms.

  1. Intraoperative study on anthropometry and gender differences of the proximal tibial plateau at the arthroplasty resection surface.

    Yang, Bo; Yu, Jiakuo; Gong, Xi; Chen, Lianxu; Wang, Yongjian; Wang, Jian; Wang, Haijun; Zhang, Jiying

    2014-01-01

    The tibial plateau is asymmetric with a larger medial plateau. We observed from clinical practice that the shape of the tibial plateau does not always present a larger medial plateau. Tibial plateau also showed other shapes. The purpose of this study was to analyze the anthropometric data of the proximal tibia in a large group of Chinese patients undergoing total knee arthroplasty and to investigate the morphology of the resected proximal tibial surface and its gender differences. A total of 822 knees (164 males, 658 females) from the Chinese population were measured intraoperatively for medial anteroposterior (MAP) and lateral anteroposterior (LAP) dimensions of the resected proximal tibial surface. The difference of MAP and LAP (DML) was also calculated as MAP minus LAP. We then classified the data into three groups based on the DML (2 mm) to analyze the morphology of the proximal tibia and its distribution between male and female. The shape of proximal tibial plateau was of three types: larger medial plateau type, symmetric type, and larger lateral plateau type. There were significant differences between males and females in relation to the shape distribution of the proximal tibial plateau (P 2 mm and 120 of 822 (14.6%) tibia having a DMLDMLs to better match the different anthropometry of the resected tibial surface.

  2. The effect of tibial slope on the biomechanics of cruciate-retaining TKA : a musculoskeletal simulation study

    Marra, Marco A.; Strzelczak, Marta; Heesterbeek, Petra J.C.; van de Groes, Sebastiaan; Janssen, Dennis W.; Koopman, Bart F.J.M.; Wymenga, Ate B.; Verdonschot, Nico J.J.

    2017-01-01

    INTRODUCTION: Tibial slope can affect the outcomes of Total Knee Arthroplasty (TKA). More posterior slope potentially helps releasing a too tight flexion gap and it is generally associated with a wider range of post-operative knee flexion. However, the mechanism by which tibial slope affects the

  3. The arthroscopic treatment of displaced tibial spine fractures in children and adolescents using Meniscus Arrows(A (R))

    Wouters, Diederick B.; de Graaf, Joost S.; Hemmer, Patrick H.; Burgerhof, Johannes G. M.; Kramer, William L. M.

    This article summarises the results of a newly developed technique that utilises Meniscus Arrows(A (R)) for the arthroscopic fixation of displaced tibial spine fractures in children and adolescents. Twelve tibial spine fractures in the knees of eleven children between 6 and 15 years old, with an

  4. Anterior referencing of tibial slope in total knee arthroplasty considerably influences knee kinematics : a musculoskeletal simulation study

    Marra, Marco Antonio; Strzelczak, Marta; Heesterbeek, Petra J.C.; van de Groes, Sebastiaan A.W.; Janssen, Dennis W.; Koopman, Bart F.J.M.; Wymenga, Ate B.; Verdonschot, Nico J.J.

    2017-01-01

    Purpose: In total knee arthroplasty (TKA), the posterior tibial slope is not always reconstructed correctly, and the knee ligaments may become too tight in flexion. To release a tight flexion gap, surgeons can increase the posterior tibial slope using two surgical resection techniques: the anterior

  5. Stress og aldring

    Jørgensen, Anders; Jørgensen, Martin Balslev; Poulsen, Henrik Enghusen

    2012-01-01

    Accumulating evidence supports the popular notion that psychological stress states may accelerate aging. Stress has been shown to influence cellular systems known to be involved in the aging process. Furthermore, stress is associated with an increased risk of various age-related medical disorders....... These effects are likely mediated by the secretion of stress hormones. In this short review we focus on biochemical and epidemiological evidence for a link between stress and aging....

  6. Age variations in the properties of human tibial trabecular bone and cartilage

    Ding, Ming

    2000-01-01

    , such as apparent, apparent ash and collagen densities of human tibial trabecular bone have significant relationships with age. Tissue density and mineral concentration remain constant throughout life. Trabecular bone is tougher in the younger age, i.e. fracture requires more energy. Collagen density was the single......Initiated and motivated by clinical and scientific problems such as age-related bone fracture, prosthetic loosening, bone remodeling, and degenerative bone diseases, much significant research on the properties of trabecular bone has been carried out over the last two decades. This work has mainly...... focused on the central vertebral trabecular bone, while little is known about age-related changes in the properties of human peripheral (tibial) trabecular bone. Knowledge of the properties of peripheral (tibial) trabecular bone is of major importance for the understanding of degenerative diseases...

  7. Tibial nerve intraneural ganglion cyst in a 10-year-old boy

    Squires, Judy H. [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati, OH (United States); Emery, Kathleen H.; Johnson, Neil [Cincinnati Children' s Hospital Medical Center, Division of Radiology, Cincinnati, OH (United States); Sorger, Joel [Cincinnati Children' s Hospital Medical Center, Division of Orthopedics, Cincinnati, OH (United States)

    2014-04-15

    Intraneural ganglion cysts are uncommon cystic lesions of peripheral nerves that are typically encountered in adults. In the lower extremity, the peroneal nerve is most frequently affected with involvement of the tibial nerve much less common. This article describes a tibial intraneural ganglion cyst in a 10-year-old boy. Although extremely rare, intraneural ganglion cysts of the tibial nerve should be considered when a nonenhancing cystic structure with intra-articular extension is identified along the course of the nerve. This report also details the unsuccessful attempt at percutaneous treatment with US-guided cyst aspiration and steroid injection, an option recently reported as a viable alternative to open surgical resection. (orig.)

  8. Regional fibrocartilage variations in human anterior cruciate ligament tibial insertion: a histological three-dimensional reconstruction.

    Dai, Can; Guo, Lin; Yang, Liu; Wu, Yi; Gou, Jingyue; Li, Bangchun

    2015-02-01

    We studied anterior cruciate ligament (ACL) tibial insertion architecture in humans and investigated regional differences that could suggest unequal force transmission from ligament to bone. ACL tibial insertions were processed histologically. With Photoshop software, digital images taken from the histological slides were collaged, contour lines were drawn, and different gray values were filled based on the structure. The data were exported to Amira software for three-dimensional reconstruction. The uncalcified fibrocartilage (UF) layer was divided into three regions: lateral, medial and posterior according to the architecture. The UF zone was significantly thicker laterally than medially or posteriorly (p fibrocartilage (CF) thickness was significantly greater in the lateral part of the enthesis compared to the medial and posterior parts (p < 0.05). The UF quantity (more UF laterally) corresponding to the CF quantity (more CF laterally) at the ACL tibial insertion provides further evidence suggesting that the load transferred from the ACL to the tibia was greater laterally than medially and posteriorly.

  9. Intramedullary versus extramedullary alignment of the tibial component in the Triathlon knee

    Cashman, James P

    2011-08-20

    Abstract Background Long term survivorship in total knee arthroplasty is significantly dependant on prosthesis alignment. Our aim was determine which alignment guide was more accurate in positioning of the tibial component in total knee arthroplasty. We also aimed to assess whether there was any difference in short term patient outcome. Method A comparison of intramedullary versus extramedullary alignment jig was performed. Radiological alignment of tibial components and patient outcomes of 103 Triathlon total knee arthroplasties were analysed. Results Use of the intramedullary was found to be significantly more accurate in determining coronal alignment (p = 0.02) while use of the extramedullary jig was found to give more accurate results in sagittal alignment (p = 0.04). There was no significant difference in WOMAC or SF-36 at six months. Conclusion Use of an intramedullary jig is preferable for positioning of the tibial component using this knee system.

  10. Acceleration and holographic studies on different types of dynamization of external fixators of the bones

    Podbielska, Halina; Kasprzak, Henryk T.; Voloshin, Arkady S.; Pennig, Dietmar; von Bally, Gert

    1992-08-01

    The unilateral axially dynamic fixator (Orthofix) was mounted on a sheep tibial shaft. Three fixation modes: static, dynamic controlled, and dynamic free were examined by means of double exposure holographic interferometry. Simultaneously, the acceleration was measured by an accelerometer and displayed on the monitor together with loading characteristics. The first exposure was made before the acting force was applied to the tibia plateau. The second one after the moment when the acceleration wave started to propagate through the specimen. We stated that in the case of dynamization less torsion occurs at the fracture site. So far, we have not been able to determine any correlation between results of holographic and accelerometric measurements.

  11. Medialt tibialt stress syndrom - en oversikt

    Tømmerstrand, Jørn Yngve

    2016-01-01

    The objective of this thesis is to give a thorough presentation of medial tibial stress syndrome (MTSS) with emphasis on pathophysiology, aetiology, diagnostics and treatment options. MTSS is one of the most common exercise induced overuse injuries in athletes and military personnel. It is defined as exercise induced pain along a segment of at least 5 cm localized to the distal 2/3 of the posteromedial border of the tibia. The pathophysiological mechanisms of this condition is disputed. A tra...

  12. An Incidental Finding of a Talonavicular and Talocalcaneal Joint Coalition After a Tibial Pilon Fracture: A Case Report.

    Godoy, Heidi M; Micciche, Mark J

    It has been proposed that patients with talocalcaneal and talonavicular coalitions have decreased ankle joint range of motion. It has also been reported that rotational forces regularly absorbed by the talocalcaneal joint are transferred to the ankle joint in patients with coalitions, increasing the stress on the ankle joint after trauma. To the best of our knowledge, only 1 reported study has detailed the increased stress placed on the ankle joint secondary to a coalition. We present a case study of a 53-year-old female who experienced a traumatic fall and subsequent right ankle fracture. Advanced imaging studies revealed a comminuted tibial pilon fracture and talocalcaneal and talonavicular joint coalitions. She underwent open reduction and internal fixation for treatment of the fracture, and the coalitions were not treated because they were asymptomatic. She was kept non-weightbearing for 6 weeks postoperatively and was returned to a regular sneaker at 10 weeks postoperatively. The postoperative films revealed stable intact fixation and pain-free gait with no increased restriction in her ankle joint range of motion. The hardware was removed at 13 months postoperatively. She had not experienced increased pain or arthritic changes at 15 months postoperatively. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  13. A STUDY ON TIBIAL TORSION IN ADULT DRY TIBIA OF EAST AND SOUTH INDIAN POPULATION

    Jami Sagar Prusti

    2017-05-01

    Full Text Available BACKGROUND Rotational deformities of the lower limbs are very common. There is increasing evidence that abnormal torsion in the tibia is associated with severe knee and ankle arthritis. Primary knee osteoarthritis is a leading cause of disability in older persons. Varus or valgus alignment increases the risk of osteoarthritis. Coexistence of tibial torsional deformity may increase the risk further. Variability in the tibial torsion has been reported and is due to the torsional forces applied on tibia during development. The aim of the study is to estimate the angle of tibial torsion on both sides and both sexes. The present study was an attempt to provide baseline data of tibial torsion in the East and South Indian population. MATERIALS AND METHODS The study was conducted mechanically on 100 dry adult unpaired human tibia, i.e. 50 male and 50 female bones. The measurements were recorded and statistically analysed using Student’s unpaired t-test using GraphPad Prism 5.0 (free trial version. RESULTS Out of the 100 tibia undertaken, mean value of tibial torsion angle obtained is 25.8°. In males, it is 23.68° and in females it is about 27.86°. Statistical analysis revealed significant greater average angle of tibial torsion in female bones. The angle of the right-sided bones was more and this was statistically significant. CONCLUSION The gender variation for the angle could be the result of the difference in lifestyle in day-to-day activities. The knowledge of the angle in a population could be helpful in understanding the incidence of pathogenesis related to gait and knee osteoarthritis and in view of reconstructive surgeries in orthopaedic practice.

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

    Singh, Kunwarpal; Gupta, Kamlesh; Kaur, Sukhdeep

    2017-12-01

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

  15. Short-Term Nose-Only Water-Pipe (Shisha Smoking Exposure Accelerates Coagulation and Causes Cardiac Inflammation and Oxidative Stress in Mice

    Abderrahim Nemmar

    2015-01-01

    Full Text Available Background/Aim: Water-pipe smoking (WPS has acquired worldwide popularity, and is disseminating particularly rapidly in Europe and North America. However, little is known about the short-term cardiovascular effects of WPS. Methods: Presently, we assessed the short-term cardiovascular effects of nose-only exposure to mainstream WPS in BALB/c mice for 30 min/day for 5 consecutive days. Control mice were exposed to air. At the end of the exposure period, several cardiovascular endpoints were measured. Results: WPS did not affect the number of leukocytes and the plasma concentrations of C-reactive protein, tumor necrosis factor α (TNFα and interleukin-6 (IL-6. Likewise, plasma levels of lipid peroxidation (LPO, reduced glutathione (GSH and catalase were not affected by WPS. By contrast, WPS aggravated in vivo thrombosis by shortening the thrombotic occlusion time in pial arterioles and venules. The number of circulating platelets was reduced by WPS suggesting the occurrence of platelet aggregation in vivo. Elevated concentrations of fibrinogen and plasminogen activator inhibitor-1 were seen after the exposure to WPS. Blood samples taken from mice exposed to WPS and exposed to adenosine diphosphate showed more platelet aggregation. The heart concentrations of IL-6 and TNFα were augmented by WPS. Likewise, heart levels of LPO, reactive oxygen species and the antioxidants catalase and GSH were increased by WPS. However, the systolic blood pressure and heart rate were not affected by WPS. Conclusion: It can be concluded that short-term exposure to WPS exerts procoagulatory effects and induce cardiac inflammation and oxidative stress. At the time point investigated, there was no evidence for blood inflammation or oxidative stress.

  16. Anterior avulsion fracture of the tibial tuberosity in adolescents - Two case reports

    Aleilimar Teixeira da Silva Júnior

    Full Text Available ABSTRACT The objective here was to report two rare cases of anterior avulsion fracture of the tibial tuberosity in adolescents. Case 1 was a 15-year-old male who became injured through landing on his left knee and presented limited extension. Case 2 was a 16-year-old basketball player who presented sudden pain in the right knee and functional incapacity, after a jump. Imaging examinations (radiographs and computed tomography showed anterior avulsion fractures of the tibial tuberosity. Surgical fixation was performed using screws and anchors, while avoiding growth plate injury. The cases evolved without lower-limb deformities.

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

    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.

  18. Simultaneous bilateral tibial tubercle avulsion fracture in a male teenager: case report and literature review.

    Nicolini, Alexandre P; Carvalho, Rogerio T; Ferretti, Mario; Cohen, Moises

    2018-01-01

    Tibial tuberosity avulsion fractures are injuries accounting for less than 3% of all epiphyseal and 1% of all physeal injuries in adolescents. Bilateral injuries are very rare, with only 19 cases described in the literature. These types of fractures occur commonly in male teenagers during sport activities and are often associated with other orthopaedic disorders. We report the case of a male teenager with simultaneous bilateral tibial tubercle fractures, describe the evolution and treatment of this injury and review the literature on this subject. Case report.

  19. The clinico-anatomic explanation for tibial intraneural ganglion cysts arising from the superior tibiofibular joint

    Spinner, Robert J. [Mayo Clinic, Department of Neurologic Surgery, Rochester, Minnesota (United States); Mayo Clinic, Department of Orthopedic Surgery, Rochester, Minnesota (United States); Mayo Clinic, Department of Anatomy, Rochester, Minnesota (United States); Mokhtarzadeh, Ali; Schiefer, Terry K. [Mayo Clinic College of Medicine, Rochester, Minnesota (United States); Krishnan, Kartik G. [Carl Gustav Carus University Hospital, Department of Neurological Surgery, Dresden (Germany); Kliot, Michel [University of Washington, Department of Neurosurgery, Seattle, Washington (United States); Amrami, Kimberly K. [Mayo Clinic, Department of Radiology, Rochester, Minnesota (United States)

    2007-04-15

    To demonstrate that tibial intraneural ganglia in the popliteal fossa are derived from the posterior portion of the superior tibiofibular joint, in a mechanism similar to that of peroneal intraneural ganglia, which have recently been shown to arise from the anterior portion of the same joint. Retrospective clinical study and prospective anatomic study. The clinical records and MRI findings of three patients with tibial intraneural ganglion cysts were analyzed and compared with those of one patient with a tibial extraneural ganglion cyst and one volunteer. Seven cadaveric limbs were dissected to define the articular anatomy of the posterior aspect of the superior tibiofibular joint. The condition of the three patients with intraneural ganglia recurred because their joint connections were not identified initially. In two patients there was no cyst recurrence when the joint connection was treated at revision surgery; the third patient did not wish to undergo additional surgery. The one patient with an extraneural ganglion had the joint connection identified at initial assessment and had successful surgery addressing the cyst and the joint connection. Retrospective evaluation of the tibial intraneural ganglion cysts revealed stereotypic features, which allowed their accurate diagnosis and distinction from extraneural cases. The intraneural cysts had tubular (rather than globular) appearances. They derived from the postero-inferior portion of the superior tibiofibular joint and followed the expected course of the articular branch on the posterior surface of the popliteus muscle. The cysts then extended intra-epineurially into the parent tibial nerves, where they contained displaced nerve fascicles. The extraneural cyst extrinsically compressed the tibial nerve but did not directly involve it. All cadaveric specimens demonstrated a small single articular branch, which derived from the tibial nerve to the popliteus. The branch coursed obliquely across the posterior

  20. Atypical presentation of popliteal artery entrapment syndrome: involvement of the anterior tibial artery.

    Bou, Steven; Day, Carly

    2014-11-01

    Popliteal artery entrapment syndrome (PAES) is a rare condition that should be suspected in a young patient with exertional lower extremity pain. We report the case of an 18-year-old female volleyball player with bilateral exertional lower extremity pain who had been previously diagnosed with tendinitis and periostitis. Diagnostic studies showed entrapment of the left popliteal artery and the left anterior tibial artery. To our knowledge, there has only been 1 previous report of anterior tibial artery involvement in PAES. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  1. Posterior Tibial Neuropathy by a Baker’s Cyst: Case Report

    Lee, Ji-Hyun; Jun, Jae-Bum; Choi, Choong-Hyeok; Park, Si-Bog; Yoo, Dae-Hyun; Hong, Eun-Kyung; Kim, Seong Yoon

    2000-01-01

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

  2. Canine stifle joint biomechanics associated with tibial plateau leveling osteotomy predicted by use of a computer model.

    Brown, Nathan P; Bertocci, Gina E; Marcellin-Little, Denis J

    2014-07-01

    To evaluate effects of tibial plateau leveling osteotomy (TPLO) on canine stifle joint biomechanics in a cranial cruciate ligament (CrCL)-deficient stifle joint by use of a 3-D computer model simulating the stance phase of gait and to compare biomechanics in TPLO-managed, CrCL-intact, and CrCL-deficient stifle joints. Computer simulations of the pelvic limb of a Golden Retriever. A previously developed computer model of the canine pelvic limb was used to simulate TPLO stabilization to achieve a tibial plateau angle (TPA) of 5° (baseline value) in a CrCL-deficient stifle joint. Sensitivity analysis was conducted for tibial fragment rotation of 13° to -3°. Ligament loads, relative tibial translation, and relative tibial rotation were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints. TPLO with a 5° TPA converted cranial tibial translation to caudal tibial translation and increased loads placed on the remaining stifle joint ligaments, compared with results for a CrCL-intact stifle joint. Lateral collateral ligament load was similar, medial collateral ligament load increased, and caudal cruciate ligament load decreased after TPLO, compared with loads for a CrCL-deficient stifle joint. Relative tibial rotation after TPLO was similar to that of a CrCL-deficient stifle joint. Stifle joint biomechanics were affected by TPLO fragment rotation. In the model, stifle joint biomechanics were partially improved after TPLO, compared with CrCL-deficient stifle joint biomechanics, but TPLO did not fully restore CrCL-intact stifle joint biomechanics. Overrotation of the tibial fragment negatively influenced stifle joint biomechanics by increasing caudal tibial translation.

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

    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.

  4. Bone Regeneration Is Promoted by Orally Administered Bovine Lactoferrin in a Rabbit Tibial Distraction Osteogenesis Model.

    Li, Wenyang; Zhu, Songsong; Hu, Jing

    2015-07-01

    Lactoferrin, an iron-binding glycoprotein which belongs to the transferrin family, has been shown to promote bone growth. However, reports regarding effects of lactoferrin on bone regeneration during distraction osteogenesis are limited. Our study was designed to investigate the effect of bovine lactoferrin treatment on bone formation of the distracted callus. We asked whether bovine lactoferrin enhances bone formation of the distraction callus as determined by (1) radiographic and histologic appearances; (2) dual-energy x-ray absorptiometry (DXA) analysis of bone mineral composition and bone mineral density; (3) micro-CT measures of trabecular architecture; and (4) biomechanical strength of the healing bone. Additionally, serology, reverse transcription (RT)-PCR, and immunohistochemistry were used to explore the possible mechanisms of bovine lactoferrin use on bone formation during distraction osteogenesis. Unilateral tibial osteodistraction was performed on 80 New Zealand White rabbits with a distraction rate of 1 mm per day for 10 days. Animals then were divided randomly into two groups: (1) vehicle and (2) bovine lactoferrin. At 4 and 8 weeks after completion of distraction, the animals were sacrificed. Lengthened tibias and serum samples were obtained and subjected to radiologic, DXA, micro-CT, histologic, and biomechanical examinations, and serum, RT-PCR and immunohistochemical analyses. Radiologic, DXA, micro-CT, histologic, and biomechanical examinations indicated that bovine lactoferrin treatment not only accelerated bone formation at early stages of distraction osteogenesis but also promoted bone consolidation at late stages. The ultimate force of the distracted calluses was increased by 37% (118.8 ± 6.65 N in the lactoferrin group and 86.5 ± 5.47 N in the vehicle group; p bovine lactoferrin treatment significantly increased serum levels of bone alkaline phosphatase and decreased serum levels of tartrate resistant acid phosphatase 5b. In addition, RT

  5. Longitudinal stress fracture: patterns of edema and the importance of the nutrient foramen

    Craig, Joseph G.; Widman, David; Holsbeeck, Marnix van [Department of Radiology, Henry Ford Hospital, Detroit, MI 48202 (United States)

    2003-01-01

    We reviewed the MR appearances of six cases of longitudinal stress fracture of the lower extremity.Results. One fracture was in the femur and five were in the tibia. Four of the tibial fractures showed edema starting in the mid-tibia at the level of the nutrient foramen with the fracture on the anteromedial cortex. The other tibial fracture started at the nutrient foramen. Three fractures (two tibial and the femur fracture) showed eccentric marrow edema; all fractures showed either eccentric periosteal reaction or soft tissue edema.Conclusion. Primary diagnosis of longitudinal stress fracture is made by finding a vertical cleft on one or more axial images. Secondary signs of position of the nutrient foramen and patterns of edema may be useful. (orig.)

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

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

    2016-09-01

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

  7. Regional bone geometry of the tibia in triathletes and stress reactions--an observational study.

    Newsham-West, Richard J; Lyons, Brett; Milburn, Peter D

    2014-03-01

    The association between tibial morphology and tibial stress fractures or tibial stress syndrome was examined in triathletes with an unusually high incidence of these injuries. A cross-sectional study design examined associations between tibial geometry from MRI images and training and injury data between male and female triathletes and between stress fracture (SF) and non-stress fracture (NSF) groups. Fifteen athletes (7 females, 8 males) aged 17-23 years who were currently able to train and race were recruited from the New Zealand Triathlete Elite Development Squad. Geometric measurements were taken at 5 zones along the tibia using MRI and compared between symptomatic and asymptomatic tibiae subjects. SF tibiae displayed either oedema within the cancellous bone and/or stress fracture on MRI. When collapsed across levels, symptomatic tibiae had thicker medial cortices (F1,140=9.285, p=0.003), thicker lateral cortices (F1,140=10.129, p=0.002) and thinner anterior cortices (F1,140=14.517, p=0.000) than NSF tibiae. Only medial cortex thickness in SF tibia was significantly different (F4,140=3.358, p=0.012) at different levels. Follow-up analysis showed that athletes showing oedema within the cancellous bone and/or stress fracture on MRI had, within 2 years of analysis, subsequently taken time off training and racing due a tibial stress fracture. The thinner anterior cortex in SF tibiae is associated with a stress reaction in these triathletes. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter

    Ali Al Kaissi

    2014-01-01

    Full Text Available Background: Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Materials and Methods: Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. Results: The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. Conclusion: This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  9. DIAGNOSTIC BLOCKS OF THE TIBIAL NERVE IN SPASTIC HEMIPARESIS - EFFECTS ON CLINICAL, ELECTROPHYSIOLOGICAL AND GAIT PARAMETERS

    ARENDZEN, JH; VANDUIJN, H; BECKMANN, MKF; HARLAAR, J; VOGELAAR, TW; PREVO, AJH

    The value of a diagnostic block (DB) of the tibial nerve in 17 hemiparetic patients with gait disturbances was investigated. The purpose of this study was to find instruments that help to select patients who will benefit from a long lasting peripheral nerve block. The manually elicited ankle clonus

  10. Prediction of progression of radiographic knee osteoarthritis using tibial trabecular bone texture

    Woloszynski, T; Podsiadlo, P; Stachowiak, G W

    2012-01-01

    OBJECTIVE.: To develop a system for prediction of progression of radiographic knee osteoarthritis (OA) using tibial trabecular bone (TB) texture. METHODS.: We studied 203 knees with (n=68) or without (n=135) radiographic tibiofemoral OA in 105 subjects (90 men, 15 women, mean age 54 years) who ha...

  11. Preoperative estimation of tibial nail length--because size does matter.

    Galbraith, J G

    2012-11-01

    Selecting the correct tibial nail length is essential for satisfactory outcomes. Nails that are inserted and are found to be of inappropriate length should be removed. Accurate preoperative nail estimation has the potential to reduce intra-operative errors, operative time and radiation exposure.

  12. Hindfoot Valgus following Interlocking Nail Treatment for Tibial Diaphysis Fractures: Can the Fibula Be Neglected?

    Metin Uzun

    2014-01-01

    Full Text Available Purpose. We evaluated whether intramedullary nail fixation for tibial diaphysis fractures with concomitant fibula fractures (except at the distal one-third level managed conservatively with an associated fibula fracture resulted in ankle deformity and assessed the impact of the ankle deformity on lower extremity function. Methods. Sixty middle one-third tibial shaft fractures with associated fibular fractures, except the distal one-third level, were included in this study. All tibial shaft fractures were anatomically reduced and fixed with interlocking intramedullary nails. Fibular fractures were managed conservatively. Hindfoot alignment was assessed clinically. Tibia and fibular lengths were compared to contralateral measurements using radiographs. Functional results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS and the Foot and Ankle Disability Index Score (FADI. Results. Anatomic union, defined as equal length in operative and contralateral tibias, was achieved in 60 fractures (100%. Fibular shortening was identified in 42 fractures (68%. Mean fibular shortening was 1.2 cm (range, 0.5–2 cm. Clinical exams showed increased hindfoot valgus in 42 fractures (68%. The mean KOOS was 88.4, and the mean FADI score was 90. Conclusion. Fibular fractures in the middle or proximal one-third may need to be stabilized at the time of tibial intramedullary nail fixation to prevent development of hindfoot valgus due to fibular shortening.

  13. Measurement repeatability of tibial tuberosity-trochlear groove offset distance in red fox (Vulpes vulpes) cadavers

    Miles, J.E.; Jensen, B.R.; Kirpensteijn, J.; Svalastoga, E.L.; Eriksen, T.

    2013-01-01

    Abstract OBJECTIVE: To describe CT image reconstruction criteria for measurement of the tibial tuberosity-trochlear groove (TT-TG) offset distance, evaluate intra- and inter-reconstruction repeatability, and identify key sources of error in the measurement technique, as determined in vulpine hind

  14. Fixator-assisted medial tibial plateau elevation to treat severe Blount's disease: outcomes at maturity.

    Fitoussi, F; Ilharreborde, B; Lefevre, Y; Souchet, P; Presedo, A; Mazda, K; Penneçot, G F

    2011-04-01

    Severe forms of Blount's disease may be associated with medial tibial plateau (MTP) depression. Management should then take account of joint congruence, laxity, limb axis, torsional abnomality, leg length discrepancy (LLD) and eventual recurrence history. Eight knees (six patients) were managed in a single step comprising MTP elevation osteotomy, lateral epiphysiodesis and proximal tibia osteotomy to correct varus and rotational deformity. Fixation was achieved using an Ilizarov external fixator. Mean age was 10.5 years. Mean hip-knee-ankle (HKA) angle was 151°; distal femoral varus, 94°; metaphyseal-diaphyseal angle (MDA), 27°; and angle of depression of the medial tibial plateau (ADMTP), 42°. Predicted residual proximal tibial growth was 2.6 cm. At a mean 48 months' follow-up, results were good in six cases, medium in one and poor (due to incomplete lateral epiphysiodesis) in one. Mean lateral tibial torsion was 9° and final LLD 11 mm. Weight-bearing was resumed at 2 months, and the fixator was removed at 5.5 months postoperatively. At end of follow-up, mean HKA angle was 179.6°, MDA 7.3° and ADMTP 5.4°. This technically demanding procedure gave satisfactory results in terms of axes and congruence; longer term assessment remains needed. Level IV. Retrospective study. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  15. Analysis of the characteristics of patients with open tibial fractures of Gustilo and Anderson type III

    Frederico Carlos Jaña Neto

    2016-04-01

    Full Text Available OBJECTIVE: To analyze the characteristics of patients with Gustilo-Anderson Type III open tibial fractures treated at a tertiary care hospital in São Paulo between January 2013 and August 2014. METHODS: This was a cross-sectional retrospective study. The following data were gathered from the electronic medical records: age; gender; diagnosis; trauma mechanism; comorbidities; associated fractures; Gustilo and Anderson, Tscherne and AO classifications; treatment (initial and definitive; presence of compartment syndrome; primary and secondary amputations; MESS (Mangled Extremity Severity Score index; mortality rate; and infection rate. RESULTS: 116 patients were included: 81% with fracture type IIIA, 12% IIIB and 7% IIIC; 85% males; mean age 32.3 years; and 57% victims of motorcycle accidents. Tibial shaft fractures were significantly more prevalent (67%. Eight patients were subjected to amputation: one primary case and seven secondary cases. Types IIIC (75% and IIIB (25% predominated among the patients subjected to secondary amputation. The MESS index was greater than 7 in 88% of the amputees and in 5% of the limb salvage group. CONCLUSION: The profile of patients with open tibial fracture of Gustilo and Anderson Type III mainly involved young male individuals who were victims of motorcycle accidents. The tibial shaft was the segment most affected. Only 7% of the patients underwent amputation. Given the current controversy in the literature about amputation or salvage of severely injured lower limbs, it becomes necessary to carry out prospective studies to support clinical decisions.

  16. The Changed Route of Anterior Tibial Artery due to Healed Fracture

    Kemal Gökkuş

    2016-01-01

    Full Text Available We would like to highlight unusual sequelae of healed distal third diaphyseal tibia fracture that was treated conservatively 36 years ago, in which we incidentally detected peripheral CT angiography. The anterior tibial artery was enveloped three-quarterly by the healing callus of the bone (distal tibia.

  17. Popliteal versus tibial retrograde access for subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique.

    Hua, W R; Yi, M Q; Min, T L; Feng, S N; Xuan, L Z; Xing, J

    2013-08-01

    This study aimed to ascertain differences in benefit and effectiveness of popliteal versus tibial retrograde access in subintimal arterial flossing with the antegrade-retrograde intervention (SAFARI) technique. This was a retrospective study of SAFARI-assisted stenting for long chronic total occlusion (CTO) of TASC C and D superficial femoral lesions. 38 cases had superficial femoral artery lesions (23 TASC C and 15 TASC D). All 38 cases underwent SAFARI-assisted stenting. The ipsilateral popliteal artery was retrogradely punctured in 17 patients. A distal posterior tibial (PT) or dorsalis pedis (DP) artery was retrogradely punctured in 21 patients, and 16 of them were punctured after open surgical exposure. SAFARI technical success was achieved in all cases. There was no significant difference in 1-year primary patency (75% vs. 78.9%, p = .86), secondary patency (81.2% vs. 84.2%, p = .91) and access complications (p = 1.00) between popliteal and tibial retrograde access. There was statistical difference in operation time between popliteal (140.1 ± 28.4 min) and tibial retrograde access with PT/DP punctures after surgical vessel exposure (120.4 ± 23.0 min, p = .04). The SAFARI technique is a safe and feasible option for patients with infrainguinal CTO (TASC II C and D). The PT or DP as the retrograde access after surgical vessel exposure is a good choice when using the SAFARI technique. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  18. Quantitative comparison of the microscopic anatomy of the human ACL femoral and tibial entheses.

    Beaulieu, Mélanie L; Carey, Grace E; Schlecht, Stephen H; Wojtys, Edward M; Ashton-Miller, James A

    2015-12-01

    The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed-effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9-fold more acute ligament attachment angle than the tibial enthesis (p<0.001), a 43% greater calcified fibrocartilage tissue area (p<0.001), and a 226% greater uncalcified fibrocartilage depth (p<0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  19. The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

    Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

    2013-12-01

    To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

  20. Tibial avulsion fracture of the posterior root of the medial meniscus in children

    Iversen, Jonas Vestergård; Krogsgaard, Michael Rindom

    2012-01-01

    of displaced avulsion fractures of the posterior root of the medial meniscus in children are presented along with a concise report of the literature regarding avulsion fractures of the posterior root of the medial meniscus. Both avulsions were reattached arthroscopically by trans-tibial pull-out sutures...