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Purpose of Review: Stress fractures at weight-bearing sites, particularly the tibia, are common in military recruits and athletes. This review presents recent findings from human imaging and biomechanics studies aimed at predicting and preventing stress fractures., Recent Findings: Peripheral quantitative computed tomography (pQCT) provides evidence that cortical bone geometry (tibial width and area) is associated with tibial stress fracture risk during weight-bearing exercise. The contribution of bone trabecular microarchitecture, cortical porosity, and bone material properties in the pathophysiology of stress fractures is less clear, but high-resolution pQCT and new techniques such as impact microindentation may improve our understanding of the role of microarchitecture and material properties in stress fracture prediction. Military studies demonstrate osteogenic outcomes from high impact, repetitive tibial loading during training. Kinetic and kinematic characteristics may influence stress fracture risk, but there is no evidence that interventions to modify biomechanics can reduce the incidence of stress fracture. Strategies to promote adaptive bone formation, in combination with improved techniques to assess bone strength, present exciting opportunities for future research to prevent stress fractures., (© 2021. Crown.)

Background: Congenital pseudarthrosis of the tibia is a rare and challenging pediatric condition. The pre-fracture state, called congenital tibial dysplasia or anterolateral bowing of the tibia, presents a high fracture risk due to underlying bowing and dysplasia. After fracture, there is a substantial risk of nonunion. Any union achieved may be complicated by refracture, deformity, leg-length discrepancy, stiffness, pain, and dysfunction. We present the results of using distal tibial growth modulation to improve tibial alignment and to decrease fracture risk in this condition. To our knowledge, this is the first report of isolated distal tibial growth modulation as the primary surgical treatment for this condition., Methods: This is a retrospective study of 10 patients with congenital tibial dysplasia who presented prior to pseudarthrosis and underwent distal tibial growth modulation as a primary treatment. The medical records and radiographs were reviewed for age at the times of diagnosis and treatment, fracture, secondary procedures, complications, residual deformity, cystic changes, and leg-length discrepancy., Results: Ten patients had a mean follow-up (and standard deviation) of 5.1 ± 1.9 years. No patient sustained a tibial fracture, and no patient developed a tibial pseudarthrosis after guided growth was initiated. The mean age at the initiation of growth modulation was 2.6 ± 1.3 years. Six patients required a plate exchange. The mean residual tibial diaphyseal angular deformity at the most recent follow-up was 4.3° ± 3.2° of varus and 8.4° ± 5.8° in the sagittal plane. Only 1 patient had a clinically important leg-length discrepancy, with the affected leg being longer., Conclusions: In this series of 10 patients with congenital tibial dysplasia, distal tibial growth modulation delayed or possibly prevented fracture, decreased tibial malalignment, improved radiographic appearance of bone quality, and preserved leg length. No patient developed tibial fracture or pseudarthrosis after the initiation of guided growth treatment. Although early results are promising, follow-up to maturity is required to define the exact role of this simple outpatient procedure in congenital tibial dysplasia., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Purpose: A recent study reported that positioning a K-wire to intersect the cutting plane at the theoretical lateral hinge location increases the lateral hinge's resistance to fracture during the opening of opening wedge high tibial osteotomy (OWHTO). The purpose of this study was to evaluate the clinical relevance of the use of this K-wire and its benefits in terms of lateral hinge protection during OWHTO in daily practice., Methods: A retrospective comparative study identified 206 patients who underwent OWHTO from January 2014 to December 2017. Among these patients, 71 had an additional K-wire (HK + group), whereas 135 did not (HK- group). The subjects meeting the inclusion criteria were included in a matched pairing process, which identified 60 patients in the HK + group and 60 patients in the HK- group. Mean follow-up time was 2.3 ± 1.0 years (range 2-4.2). Radiographic outcomes were evaluated with intraoperative and postoperative fluoroscopic imaging and with CT imaging at 6 weeks post OWHTO surgery. The knee osteoarthritis outcomes score (KOOS) was used and time needed to return to work and any kind of sports was collected., Results: Thirty six patients (30%) were found to have a LHF. Among these patients, 26 (72%) did not have an additional K-wire positioned at their theoretical lateral hinge location (HK- group) during the procedure. LHF rate for patients without additional K-wire group (HK-) was 43.3%, whereas it was 16.7% for the patients with an additional K-wire (HK +) [Odd ratio 3.8 95% CI 1.6-8.3; p = 0.005]. The mean time to return to work, return to any kind of sports, and bone union was significantly shorter for HK + group (p < 0.05)., Conclusion: This study demonstrated that during OWHTO, positioning a K-wire intersecting the cutting plane at the theoretical lateral hinge location reduced the number of intraoperative lateral hinge fractures., Level of Evidence: III retrospective case-control study.

Objectives: To examine the effectiveness of real-time haptic feedback gait retraining for reducing resultant tibial acceleration (TA-R) with runners, the retention of changes over four weeks, and the transfer of learning to overground running., Design: Case control., Setting: Biomechanical laboratory treadmill, and track-based overground, running., Participants: 18 experienced uninjured high tibial acceleration runners., Main Outcome Measures: TA-R measured while treadmill and overground running assessed at pre-, post- and 4-weeks post-intervention., Results: Across the group, a 50% reduction in TA-R was measured post-intervention (ES: 0.9, z = -18.2, p < .001), and 41% reduction at 4-weeks (ES: 0.8, z = -12.9, p < .001) with treadmill running. A 28% reduction (ES: 0.7, z = -13.2, p < .001), and a 17% reduction in TA-R were measured at these same time points when runners ran overground (ES: 0.7, z = -11.2, p < .001). All but two runners responded positively to the intervention at the post-intervention assessment. Eleven runners were categorised as positive responders to the intervention at the 4-week post-intervention., Conclusions: Haptic feedback based on TA-R appears to be as effective, but less invasive and expensive, compared to other more established modalities, such as visual feedback. This new approach to movement retraining has the potential to revolutionise the way runners engage in gait retraining., Competing Interests: Declaration of competing interest Dr. Besier is a consultant for IMeasureU-Vicon and is involved in the development of inertial sensor solutions. The sensors used in the study were purchased from IMeasureU Limited., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Purpose: With surgical modifications reflecting plate design differences of the specific rigid locking plate adding a metal wedge, uniplane high tibial osteotomy (HTO) has fewer lateral-hinge fractures and fewer plate irritations than biplane HTO., Methods: Uniplane HTO with a rigid locking plate adding a metal wedge was compared with biplane HTO with a rigid locking plate including a proximal D-hole. For comparison, the HTO patients' medical records and radiological results in a single institution were retrospectively reviewed. The Oxford knee score 2 years post-operation, CT scan at post-operative day 2 and serial standing long-bone scanography were reviewed to evaluate clinical outcome and radiological results, including the incidence of lateral-hinge fracture, plate irritation and correction loss to varus alignment., Results: A total of 103 knees, including 59 uniplane HTO and 44 biplane HTO, were enrolled. The Oxford scores were 38.1 ± 7.8 in the uniplane group and 35.9 ± 8.3 in the biplane group (ns). On CT scans, more lateral-hinge fractures developed in the biplane group, and seven knees (12%) of the uniplane group and 12 knees (27%) of the biplane group had Takeuchi type I stable hinge fracture (p < 0.05); unstable fracture was not noted in either group. Plate irritation occurred in nine knees (19%) of the uniplane group and in 14 knees (32%) of the biplane group, and the difference was statistically significant (p < 0.05)., Conclusion: In clinical situations including the use of surgical modifications reflecting plate design differences, fewer lateral-hinge fractures developed after uniplane medial opening-wedge HTO compared with biplane HTO. Uniplane HTO potentially represents a better option than biplane HTO for the prevention of lateral-hinge fracture., Level of Evidence: IV.

Purpose: It was hypothesized in this in-vitro study that positioning a K-wire intersecting the cutting plane at the theoretical lateral hinge location would limit the cut depth and help preserve the lateral hinge during the opening of the osteotomy. Objectives were (1) to compare the mechanical resistance of the hinge and the protective effect of leaving the K-wire during the opening procedure (2) to check if the K-wire would limit the depth of the osteotomy., Methods: An ex-vivo mechanical study, testing 5 pairs of fresh-frozen tibias, was designed. CT-scan based Patient-specific cutting guides were obtained to define the cutting plane and the location of the K-wire at the hinge, using standardized 3D planning protocol. In each pair, OWHTO was performed either with or without the K-wire. To evaluate the hinge's resistance to fracture, the specimens were rigidly fixed at the proximal tibia and a direct load was applied on the free tibial diaphysis to open the osteotomy. The maximum load at breakage, maximum permissible displacement and maximal angulation of the osteotomy before hinge failure was measured. To assess the preservation of an unscathed hinge (protected by the K-wire), the distance from the end of the osteotomy cut to the lateral tibial cortical was measured in mm., Results: The maximum load to hinge breakage in the K-wires PsCG knees compared to the control group (48.3 N vs 5.5 N, p = 0.004), the maximum permissible displacement (19.8 mm vs 7.5 mm, p = 0.005) and the maximal angulation of the osteotomy before hinge breakage (9.9° vs 2.9°, p = 0.002) were all statistically superior in the K-wires PsCG knees compared to the control group. A mean distance of 10 ± 1 mm between cut-bone (saw-print) and lateral hinge cortical bone was found post-performing the osteotomy and the hinge failing., Conclusion: The maximum load to breakage and the maximum permissible displacement were, respectively, 880% and 260% higher during the opening of the OWHTO in using K-wires compared to the non-K-wire control group. This confirms the mechanical advantage of using a K-wire for both stabilization and protecting the Hinge during OWHTO. This comparative cadaveric study shows an improvement of the lateral hinges resistance to failing during the opening of the osteotomy. This can be achieved by the placement of a K-wire intersecting the cutting plane at the theoretical location of the lateral hinge.

Background: Periprosthetic tibial fracture after unicompartmental knee replacement is a challenging post-operative complication. Patients have an increased risk of mortality after fracture, the majority undergo further surgery, and the revision operations are less successful. Inappropriate surgical technique increases the risk of fracture, but it is unclear which technical aspects of the surgery are most problematic and no research has been performed on how surgical factors interact., Methods: Firstly, this study quantified the typical variance in surgical cuts made during unicompartmental knee replacement (determined from bones prepared by surgeons during an instructional course). Secondly, these measured distributions were used to create a probabilistic finite element model of the tibia after replacement. A thousand finite element models were created using the Monte Carlo method, representing 1000 virtual operations, and the risk of tibial fracture was assessed., Findings: Multivariate linear regression of the results showed that excessive resection depth and making the vertical cut too deep posteriorly increased the risk of fracture. These two parameters also had high variability in the prepared synthetic bones. The regression equation calculated the risk of fracture from three cut parameters (resection depth, vertical and horizonal posterior cuts) and fit the model results with 90% correlation., Interpretation: This study introduces for the first time the application of a probabilistic approach to predict the aetiology of fracture after unicompartmental knee replacement, providing unique insight into the relative importance of surgical saw cut variations. Targeted changes to operative technique can now be considered to seek to reduce the risk of periprosthetic fracture., Competing Interests: Declaration of competing interest Some of the authors have received funding from Biomet UK Healthcare Ltd. (the manufacturer of the implant examined in this study), but the funding was unrelated to the present study., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Elevated impact loading can be detrimental to runners as it has been linked to the increased risk of tibial stress fracture and plantar fasciitis. The objective of this study was to investigate the combined effects of foot strike pattern, step rate, and anterior trunk lean gait modifications on impact loading in runners. Nineteen healthy runners performed 12 separate gait modification trials involving: three foot strike patterns (rearfoot, midfoot, and forefoot strike), two step rates (natural and 10% increased), and two anterior trunk lean postures (natural and 10-degree increased flexion). Overall, forefoot strike combined with increased step rate led to the lowest impact loading rates, and rearfoot strike combined with anterior trunk lean led to the highest impact loading rates. In addition, there were interaction effects between foot strike pattern and step rate on awkwardness and effort, such that it was both more natural and easier to transition to a combined gait modification involving forefoot strike and increased step rate than to an isolated gait modification involving either forefoot strike or increased step rate. These findings could help to inform gait modifications for runners to reduce impact loading and associated injury risks., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Alzheimer's disease (AD) and osteoporosis are progressive diseases that affect the elderly population. Both conditions are associated with fracture risk that is greater than twice that of the healthy population. Resveratrol and exercise are two treatments that have been linked with attenuation of age-related diseases, including the risk of bone fractures. In this study, we test the hypothesis that these treatments improve fracture resistance in a mouse model representative of the AD condition., Methods: Three-month-old male 3xTg-AD mice were treated for 4 months with resveratrol or exercise or both combined, and compared with wild type mice. Exercise training was performed on a treadmill at 15 m/min for 45 min/day, 5 days/week. Resveratrol was given at 4 g/kg diet in the form of pellets. Three-point bending, cross-sectional geometric, and fluorescence analyses were conducted on tibias and compared by treatment group., Results: Tibias of 3xTg mice exhibited signs of diminished bone quality and fracture under less force than age-matched wild type mice (P < 0.05). Treatment with both resveratrol and exercise improved indicators of fracture resistance and bone quality in AD mice to levels comparable to that of wild type mice (P < 0.05)., Conclusions: The 3xTg mouse model of AD is at elevated risk for limb bone fracture compared to wild type controls. Treatment with resveratrol, exercise, or both in combination improves fracture resistance and cross-sectional geometric indicators of bone strength.

Background: Being overweight may increase the risk for developing stress fracture, as overweight adults and children were reported to have greater pressure peaks and rates under the heel during walking when compared with their normal-weight counterparts. Biofeedback gait retraining was shown to reduce ground impact magnitude in adults but not yet in children., Research Question: The study examined whether overweight children have greater tibia peak positive acceleration (PPA) at ground impact during fast walking and running compared to healthy weight children, and whether visual feedback gait retraining program can be used to reduce PPA in overweight children., Methods: Twenty five overweight and 12 healthy weight children participated in the study. Overweight children were randomly assigned into either feedback group or control no-feedback group of 8 sessions training program over 2-weeks. Tibia PPA at ground impact output from a wearable inertial sensor attached to the tibia was the feedback displayed on a monitor placed in front of the treadmill during walking and running., Results: Compared to healthy weight children, overweight participants showed significant greater PPA values in running (p < 0.05), but not in fast walking. Feedback group significantly reduced PPA by 16% (p < 0.01), and these changes persisted at the 1-month follow-up., Significance: Tibia PPA may be used in evaluating overweight children as a risk assessment to potential injuries due to high ground impact during running. Gait retraining using real-time feedback of tibia PPA may be useful in rehabilitation programs to reduce ground impact in overweight children., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Tibial plateau fracture is an important complication of cementless Oxford unicompartmental knee replacement. The press fit between the keel and the bone's keel slot is responsible for primary fixation and also contributes to fracture risk. This study investigates whether the fracture risk could be reduced without compromising primary fixation, by using different instruments to widen the keel slot., Methods: Keel slots were made in polyurethane blocks (n = 60) using the standard keel cut saw blade or a new blade that was 0.2 mm wider, with adjuvant use of the cemented pick or a prototype rasp. A tibial component was pushed into and pulled out of the slots using a Dartec materials testing machine. It was assumed that the 'push-in' force was related to the risk of fracture and 'pull-out' force was related to fixation. Reproducibility studies with 10 different tibial components were undertaken., Results: The new blade required significantly lower push-in forces than the standard blade (789 N SD 130, 1411 N SD 180; P < 0.001), but the pull-out forces were not different (240 N SD 47, 230 N SD 56; P > 0.999). With the standard blade the pick decreased the push-in (818 N SD 318; P < 0.001) and pull-out (128 N SD 58; P < 0.001) forces, but the rasp had no effect. With the new blade the pick had no effect, but the rasp increased the push-in force (1390 N SD 202; P < 0.001)., Conclusions: This study suggests the fracture risk will be reduced with the new blades, with no compromise in fixation. If the new blades are used routine use of the cemented pick appears to be of no benefit., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: Patient-specific instrumentation (PSI) for unicompartmental knee arthroplasty (UKA) has been available for a few years. However, limited literature is available on this subject. Hence, the aim of this cohort study is to evaluate the 2 years' results of our first experiences with the use of PSI in UKA. It is hypothesised that there is no advantage in rate of adverse events and in radiological and functional outcomes in comparison to literature on the conventional method., Methods: This cohort included 129 knees of 122 patients, operated by one surgeon. Outcome measures were the rate of adverse events (AEs); implant position as determined on radiographs; the accuracy of the default and approved planning of the implant sizes and the patient-reported outcome measures (PROMs) preoperatively, and at 3, 12 and 24 months, postoperatively., Results: A total of 6 (4.9%) AEs were observed in this study, with 4 (3.3%) tibial fractures being the main complication. The mean postoperative biomechanical axis was 176.4° and in the majority of cases, the radiographic criteria, as determined by the manufacturer, were met. The tibial component showed 20 (16.4%) outliers in the sagittal and 3 (2.5%) outliers in the frontal plane. There were no outliers of the femoral component. For the femoral and tibial components, respectively, in 125 (96.9%) and 79 (61.7%) cases, there was an agreement between approved planning and implanted component size. All PROMs improved significantly after surgery., Conclusion: Tibial fracture was the most common AE, probably related to the transition from cemented to uncemented UKA. Perioperative modifications to the surgical technique were made in order to prevent this AE. Improvements should be made to the operation technique of the uncemented tibial plateau to obtain an adequate placement and at the same time reduce the risk for tibial fracture. The PSI technique was a reliable tool for the placement of the femoral component. Functional outcome was in line with literature on the conventional method. It is strongly recommended that the surgeon approves every preoperative plan, in order to optimise the accuracy during the PSI surgery., Level of Evidence: III.

Aims: Open wedge high tibial osteotomy (OWHTO) for medial-compartment osteoarthritis of the knee can be complicated by intra-operative lateral hinge fracture (LHF). We aimed to establish the relationship between hinge position and fracture types, and suggest an appropriate hinge position to reduce the risk of this complication., Patients and Methods: Consecutive patients undergoing OWHTO were evaluated on coronal multiplanar reconstruction CT images. Hinge positions were divided into five zones in our new classification, by their relationship to the proximal tibiofibular joint (PTFJ). Fractures were classified into types I, II, and III according to the Takeuchi classification., Results: Among 111 patients undergoing OWHTOs, 22 sustained lateral hinge fractures. Of the 89 patients without fractures, 70 had hinges in the zone within the PTFJ and lateral to the medial margin of the PTFJ (zone WL), just above the PTFJ. Among the five zones, the relative risk of unstable fracture was significantly lower in zone WL (relative risk 0.24, confidence interval 0.17 to 0.34)., Conclusion: Zone WL appears to offer the safest position for the placement of the osteotomy hinge when trying to avoid a fracture at the osteotomy site. Cite this article: Bone Joint J 2017;99B10:1313-18., (©2017 The British Editorial Society of Bone & Joint Surgery.)

Purpose: The purpose of this study was to investigate the mechanical strength of both monoplanar and biplanar medial opening-wedge high tibial osteotomy (MOWHTO) procedures and assess the risk of lateral cortex disruption for both techniques., Methods: Twelve synthetic tibia models with cortical shells were used as test models. Saw cuts for monoplanar MOWHTO and biplanar MOWHTO were generated on the test models in equal numbers (n = 6 for both groups). Wedge opening load and wedge gap distance were evaluated via compressive tests., Results: The mean gap distance just before the lateral cortex fracture in the monoplanar group was 14.7 ± 2.9 mm, which was significantly narrower than that in the biplanar group of 19.1 ± 2.0 mm (p = 0.015). The mean load just before the occurrence of lateral cortex fracture of 32.4 ± 3.2 N in the monoplanar osteotomy group was significantly lower than that in the biplanar osteotomy group of 111.8 ± 9.3 N (p = 0.009)., Conclusion: Performing a MOWHTO via the biplanar rather than the monoplanar technique allows larger-sized wedges to be opened with less risk of lateral cortical fracture. Thus, larger gaps can be opened and higher angle corrections can be achieved using the biplanar osteotomy procedure. From a clinical viewpoint, the biplanar osteotomy technique reduced the risk of lateral cortical hinge fracture during MOWHTO.

Background: In osteotomies with larger correction angles, the capacity for elastic deformation is frequently exceeded, resulting in plastic deformation and fracture of the opposite cortex, which may lead to subsequent loss of correction. An anteroposterior drill hole at the apex of the horizontal osteotomy (= hinge) is supposed to increase the capacity of the bony hinge for elastic deformation and ideally to prevent fractures of the opposite cortex., Materials and Methods: A high tibial osteotomy (HTO) using standard surgical technique was performed in 20 each of Synbones, Sawbones, and human cadaver tibial specimens. In 10 specimens per group, an additional anteroposterior hinge drilling was performed at the apex of the horizontal osteotomy. All fractures of the opposite cortex were photographically and radiographically documented. All fractures were classified according to fracture types 1-3 of the Takeuchi classification., Results: Regardless of the study group, all tibial bones with an additional hinge drilling achieved larger correction angles during the spreading of the wedge until a fracture of the opposite cortex occurred. The average correction angle of all specimens without the drill hole was 2.7°, which increased to 4.8° with the hinge drill (increase by 77.8%). In correction angles exceeding 5°, all specimen showed a hinge fracture regardless of the presence or absence of a hinge drill., Conclusions: The hinge-protecting effect is restricted to small correction angles, i. e., to unload cartilage repair regions in the absence of severe malalignment. For the treatment of varus gonarthrosis, there is no fracture-protecting effect from a hinge drill.

Aims: We aimed to investigate factors related to the technique of medial opening wedge high tibial osteotomy which might predispose to the development of a lateral hinge fracture., Patients and Methods: A total of 71 patients with 82 osteotomies were included in the study. Their mean age was 62.9 years (37 to 80). The classification of the type of osteotomy was based on whether it extended beyond the fibular head. The level of the osteotomy was classified according to the height of its endpoint., Results: At a mean follow-up of 20 months (6 to 52), a total of 15 lateral hinge fractures (18.3%) were identified. A sufficient osteotomy, in which both anterior and posterior tibial cortices were involved with extension into the lateral aspect of the plateau in relation to an anteroposterior line tangential to the medial edge of the fibular head in the CT axial plane, was seen in 48 knees (71.6%) in those without a lateral hinge fracture and in seven (46.7%) in those with a lateral hinge fracture. An osteotomy which ended above the level of the fibular head was seen in nine (13.4%) of the knees without a lateral hinge fracture and seven (46.7%) of the those with a lateral hinge fracture. There was a significant relationship between the absence of a lateral hinge fracture and both a sufficient osteotomy and one whose endpoint was at the level of the fibular head (p = 0.0451 and p = 0.0214, respectively)., Conclusion: A sufficient osteotomy involving both the anterior and posterior cortices, whose endpoint is at the level of the fibular head, should be performed when undertaking a medial opening wedge high tibial osteotomy if a lateral hinge fracture is to be avoided as a complication. Cite this article: Bone Joint J 2017;99-B:887-93., (©2017 The British Editorial Society of Bone & Joint Surgery.)

It is important to understand potential complications of tibial tuberosity osteotomies (TTOs) and how to avoid them. TTO is associated with a 1% to 3% rate of tibial fracture and 1% rate of nonunion. Early weight-bearing and complete detachment of the distal tuberosity may increase these risks. Painful screws requiring removal occur in 3% to 77% of cases. Use of small (3.5- mm diameter), countersunk screws reduces this risk. Recurrent instability occurs in ∼5% of cases at 5 years. The risk of deep-vein thrombosis (4%) after TTO is higher than that associated with other sports surgeries (1% to 2%). The risk of wound complications is ∼1% and can be reduced with meticulous handling of soft tissues and avoidance of large medial incisions. The risk of deep infection is <1%. Severe complications such as compartment syndrome and pulmonary embolism are rare.

Background: Giant cell tumors (GCTs) are treated with resection curettage and adjuvants followed by stabilization. Complications include recurrence, fracture, and joint degeneration. Studies have shown treatment with polymethylmethacrylate (PMMA) may increase the risk of joint degeneration and fracture. Other studies have suggested that subchondral bone grafting may reduce these risks., Questions/purposes: Following standard intralesional resection-curettage and adjuvant treatment, is the use of bone graft, with or without supplemental PMMA, (1) associated with fewer nononcologic complications; (2) associated with differences in tumor recurrence between patients treated with versus those treated without bone grafting for GCT; and (3) associated with differences in Musculoskeletal Tumor Society (MSTS) scores?, Methods: Between 1996 and 2014, 49 patients presented with GCT in the epiphysis of a long bone. Six patients were excluded, four who were lost to followup before 12 months and two because they presented with displaced, comminuted, intraarticular pathologic fractures with a nonreconstructable joint surface. The remaining 43 patients were included in our study at a mean followup of 59 months (range, 12-234 months). After resection-curettage, 21 patients were reconstructed using femoral head allograft with or without PMMA (JB) and 22 patients were reconstructed using PMMA alone (FRP, KSB); each surgeon used the same approach (that is, bone graft or no bone graft) throughout the period of study. The primary study comparison was between patients treated with bone graft (with or without PMMA) and those treated without bone graft., Results: Nononcologic complications occurred less frequently in patients treated with bone graft than those treated without (10% [two of 21] versus 55% [12 of 22]; odds ratio, 0.088; 95% confidence interval [CI], 0.02-0.47; p = 0.002). Patients with bone graft had increased nononcologic complication-free survival (hazard ratio, 4.59; 95% CI, 1.39-15.12; p = 0.012). With the numbers available, there was no difference in tumor recurrence between patients treated with bone graft versus without (29% [six of 21] versus 32% [seven of 22]; odds ratio, 0.70; 95% CI, 0.1936-2.531; p = 0.586) or in recurrence-free survival among patients with bone graft versus without (hazard ratio, 0.94; 95% CI, 0.30-2.98; p = 0.920). With the numbers available, there was no difference in mean MSTS scores between patients treated with bone graft versus without (92% ± 2% versus 93% ± 1.4%; mean difference 1.0%; 95% CI, -3.9% to 6.0%; p = 0.675)., Conclusions: Compared with PMMA alone, the use of periarticular bone graft constructs reduces postoperative complications apparently without increasing the likelihood of tumor recurrence., Level of Evidence: Level III, therapeutic study.

Background: 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., Methods: 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., Findings: Heelstrike runners experienced greater impact loading immediately after landing pattern switch (P<0.004). There was an increase in the longitudinal ankle joint contact force when they landed with forefoot (P=0.003). However, there was no significant difference in both peak tibial strains and the risk of tibial stress fracture in runners with different landing patterns (P>0.986)., Interpretation: 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.)

We sought to determine if an in-field gait retraining program can reduce excessive impact forces and peak hip adduction without adverse changes in knee joint work during running. Thirty healthy at-risk runners who exhibited high-impact forces were randomized to retraining [21.1 (± 1.9) years, 22.1 (± 10.8) km/week] or control groups [21.0 (± 1.3) years, 23.2 (± 8.7) km/week]. Retrainers were cued, via a wireless accelerometer, to increase preferred step rate by 7.5% during eight training sessions performed in-field. Adherence with the prescribed step rate was assessed via mobile monitoring. Three-dimensional gait analysis was performed at baseline, after retraining, and at 1-month post-retraining. Retrainers increased step rate by 8.6% (P < 0.0001), reducing instantaneous vertical load rate (-17.9%, P = 0.003), average vertical load rate (-18.9%, P < 0.0001), peak hip adduction (2.9° ± 4.2 reduction, P = 0.005), eccentric knee joint work per stance phase (-26.9%, P < 0.0001), and per kilometer of running (-21.1%, P < 0.0001). Alterations in gait were maintained at 30 days. In the absence of any feedback, controls maintained their baseline gait parameters. The majority of retrainers were adherent with the prescribed step rate during in-field runs. Thus, in-field gait retraining, cueing a modest increase in step rate, was effective at reducing impact forces, peak hip adduction and eccentric knee joint work., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: This study tested the hypothesis that a ribose-based pre-treatment would protect the strength, ductility and toughness of γ-irradiation sterilized cortical bone., Methods: Experiment 1: The effects of ribose pre-treatment (1.8M in PBS at 60°C for 24h) prior to 33 kGy of irradiation on strength, ductility and toughness (beams in three-point bending) and fracture toughness (J-integral at instability in single edge notched (bending)) were tested against matched non-irradiated and irradiated controls from bovine tibiae. Experiment 2: Three-point bending tests were conducted using beams from human femora (males, 59-67 years). Bone collagen thermal stability and network connectivity were examined using hydrothermal isometric tension testing., Results: Ribose pre-treatment protected the strength, ductility and toughness of irradiation sterilized bovine and human specimens to differing degrees. Their ultimate strength was not detectably different from non-irradiated control levels; toughness in bovine and human specimens was protected by 57 and 76%, respectively. Untreated human bone was less affected by irradiation and ribose pre-treatment was more effective in human bone than bovine bone., Conclusions: This paper presents the first proof-of-principle that irradiation-sterilized bone with improved mechanical properties can be produced through the application of a ribose pre-irradiation treatment, which provides a more stable and connected collagen network than found in conventionally irradiated controls., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objectives: Osteogenesis imperfecta (OI) frequently leads to long-bone bowing requiring a surgical intervention in severe cases to avoid subsequent fractures. However, there are no objective criteria to decide when to perform such intervention. The objective is to develop a finite element model to predict the risk of tibial fracture associated with tibia deformity in patients with OI., Methods: A comprehensive FE model of the tibia was adapted to match bi-planar radiographs of a 7 year-old girl with OI. Ten additional models with different deformed geometries (from 2° to 24°) were created and the elasto-plastic mechanical properties were adapted to reflect OI conditions. Loads were obtained from mechanography of two-legged hopping. Two additional impact cases (lateral and torsion) were also simulated. Principal strain levels were used to define a risk criterion., Results: Fracture risks for the two-legged hopping load case remained low and constant until tibia bowing reached 15° and 16° in sagittal and coronal planes respectively. Fracture risks for lateral and torsion impact were equivalent whatever the level of tibial bowing., Conclusions: The finite element model of OI tibia provides an objective means of assessing the necessity of surgical intervention for a given level of tibia bowing in OI-affected children.

Background: The increasing number of implantations of total knee endoprostheses shows a correlation with an increase in revision operations and periprosthetic fractures., Objective: This article presents strategies for prevention of complications after open reduction internal fixation (ORIF) of periprosthetic fractures in addition to the classification of periprosthetic fractures of the knee joint., Therapy Strategies: Osteosynthetic treatment is only applicable in some of the cases. Although special periprosthetic, angle locking plates are available for osteosynthesis, treatment of periprosthetic fractures of the knee joint remains a challenge with a high complication rate. If the prosthesis becomes loosened, the prosthesis should be replaced and ORIF should not be performed., Risk Factors: The risk factors for failure of osteosynthesis include the prosthesis model and the associated reduction of residual bone and the mostly osteoporotic bone structures.

Background: The publication of clinical prediction rules (CPRs) studies has risen significantly. It is unclear if this reflects increasing usage of these tools in clinical practice or how this may vary across clinical areas., Aim: To review clinical guidelines in selected areas and survey GPs in order to explore CPR usefulness in the opinion of experts and use at the point of care., Design and Setting: A review of clinical guidelines and survey of UK GPs., Method: Clinical guidelines in eight clinical domains with published CPRs were reviewed for recommendations to use CPRs including primary prevention of cardiovascular disease, transient ischaemic attack (TIA) and stroke, diabetes mellitus, fracture risk assessment in osteoporosis, lower limb fractures, breast cancer, depression, and acute infections in childhood. An online survey of 401 UK GPs was also conducted., Results: Guideline review: Of 7637 records screened by title and/or abstract, 243 clinical guidelines met inclusion criteria. CPRs were most commonly recommended in guidelines regarding primary prevention of cardiovascular disease (67%) and depression (67%). There was little consensus across various clinical guidelines as to which CPR to use preferentially., Survey: Of 401 responders to the GP survey, most were aware of and applied named CPRs in the clinical areas of cardiovascular disease and depression. The commonest reasons for using CPRs were to guide management and conform to local policy requirements., Conclusion: GPs use CPRs to guide management but also to comply with local policy requirements. Future research could focus on which clinical areas clinicians would most benefit from CPRs and promoting the use of robust, externally validated CPRs.

Purpose: The purpose of this study was to determine whether real-time feedback (RTF) training would reduce impact loading variables previously linked with tibial stress fracture risk and whether these adaptations would influence running economy., Methods: Twenty-two male runners were randomly assigned to RTF (n = 12) and control (n = 10) groups. The RTF group received feedback based on their peak tibial axial accelerations (PTA) during six 20-min treadmill runs for 3 wk, whereas the control group adhered to the same training but without feedback. Unilateral three-dimensional kinematic and kinetic analysis and running economy measurements were conducted before, after, and at 1 month posttraining., Results: The RTF group had significant reductions (P < 0.01) in PTA and average and instantaneous vertical force loading rates after training as compared with no changes in the control group. These modifications in impact loads were only maintained in PTA 1 month after the training. A significant increase (P = 0.0033) in ankle plantarflexion at initial contact and a significant change (P = 0.030) in foot strike pattern from a rearfoot to midfoot strike pattern and a significant decrease (P = 0.008) in heel vertical velocity at initial contact appeared to be the primary mechanical strategies adopted by runners to reduce impact loading after RTF training. Despite these gait adaptations, running economy was unaffected., Conclusions: The results of this study suggest that gait retraining using RTF is an effective means of eliciting reductions in impact loading without negatively affecting running economy. However, with loading rate reductions not being maintained 1 month posttraining, further research is required to determine how these reductions in impact severity can be retained long term.

A series of computational studies were performed to investigate the response of the lower extremities of mounted soldiers under landmine detonation. A numerical human body model newly developed at Wayne State University was used to simulate two types of experimental studies and the model predictions were validated against test data in terms of the tibia axial force as well as bone fracture pattern. Based on the validated model, the minimum axial force causing tibia facture was found. Then a series of parametric studies was conducted to determine the critical velocity (peak velocity of the floor plate) causing tibia fracture at different upper/lower leg angles. In addition, to limit the load transmission through the vehicular floor, two types of energy absorbing materials, namely IMPAXX(®) foam and aluminum alloy honeycomb, were selected for floor matting. Their performances in terms of blast effect mitigation were compared using the validated numerical model, and it has been found that honeycomb is a more efficient material for blast injury prevention under the loading conditions studied., (© 2013 Elsevier Ltd. All rights reserved.)

Background: The authors investigated the possibility of incorporating a well-vascularized, partial corticotomy of the anterolateral aspect of the tibia "in-series" with a dorsalis pedis fasciocutaneous free flap for oromandibular reconstruction., Methods: A cadaveric injection study was performed to characterize the vascular territory of the anterior tibial artery with regard to the surrounding osseous and soft tissue. The two-point breaking strength of the tibia (twist) was examined with fracture strain gauge analysis to determine the threshold of tibia corticotomy that would lead to a pathologic fracture. Finally, the authors performed an in vivo prospective clinical examination of the tibial-dorsalis pedis osteocutaneous shin flap., Results: The perfusion study revealed that the anterior tibial artery provided a rich matrix of musculofascial periosteal blood supply to the anterolateral cortex of the tibia that could potentially support free osseous tibial transfer. Two-point osteotomy fracture strain gauge analysis demonstrated that the threshold of tibia corticotomy that would lead to pathologic fracture of the remaining tibia was greater than 30 percent. The osteocutaneous shin flap was performed in eight patients. The mean follow-up was 61 months. There were no cases of flap loss, salivary fistula, nonunion, or tibia pathologic fracture. All patients achieved ambulation., Conclusions: The authors introduce the osteocutaneous tibial-dorsalis pedis free vascularized flap as a viable option for oromandibular reconstruction. Its most notable advantage is the independent mobility of the skin paddle, in combination with bone stock that replicates mandibular bone dimensions, facilitating primary osseointegration or denture rehabilitation., Clinical Question/level of Evidence: Therapeutic, IV.

Purpose: The purpose of this cadaveric study was to study the effect of plane of osteotomy on incidence of lateral cortex fracture and to define a "safe zone" through which medial open-wedge high tibial osteotomy (HTO) could be performed with minimal risk of lateral cortex fracture., Methods: Medial open HTO was performed in nine fresh frozen human cadavers (18 knees) with each specimen randomly assigned to a "safe zone" osteotomy (group A, between the tip of the fibular head and the circumference line of the fibular head), or a lower level osteotomy (group B, distal to the circumference line of the fibular head)., Results: Six out of nine knees developed lateral cortex fracture in group B compared to none in group A (P = 0.009) when the osteotomy site was distracted to a maximum of 20 mm., Conclusion: Directing the plane of the osteotomy toward the "safe zone" significantly reduces the risk of lateral cortex fracture compared to an osteotomy, which is directed at a lower level. Confining the plane of a medial open HTO to within the "safe zone" can prevent lateral cortex fracture and subsequent loss of correction.

Purpose: Periprosthetic tibial plateau fractures represent a rare but serious complication in unicompartmental knee arthroplasty and are associated with extended sagittal tibial bone cuts. These can occur during the surgery, weaken the posterior cortex of the tibia and are associated with periprosthetic tibial plateau fractures. Although excellent long-term results have been reported with cemented unicompartmental knee arthroplasty, there is high interest in cementless fixation. The aim of the study was to compare fracture loads of cementless and cemented unicompartmental knee arthroplasty., Methods: Tibial components of the Oxford Uni were implanted in six paired fresh-frozen tibiae with a defined extended saw cut (10°) at the dorsal cortex of each specimen. In one set, surgery was performed with cement fixation, and in the other, cementless components were implanted. Vertical loads were then applied under standardised conditions to fracture the specimens., Results: Median loads of 3.7 (0.7-6.9) kN led to fractures in the cemented group, whereas cementless fixated tibiae fractured with a median load of 1.6 (0.2-4.3) kN (P = 0.02)., Conclusion: The loading capacity in tibiae with cementless components is significantly less compared to cemented fixation. The results show that in case of an extended sagittal bone cut patients especially those with poor bone quality who are treated with a cementless unicompartmental knee arthroplasty are at higher risk for periprosthetic tibial fractures.

The purpose of the present study was to ascertain whether increase in step frequency at a given velocity during running reduces the lower extremity loading variables, which is associated with tibial stress fracture in runner. We hypothesized that the lower extremity loading variables at a given speed would be minimized at around +15% f step. 10 male subjects were asked to run at 2.5 m/s on a treadmill-mounted force platform. 5 step frequencies were controlled using a metronome: the preferred, below preferred (-15 and -30%) and above preferred (+15 and +30%). From the vertical ground reaction force, we measured following lower extremity loading variables; vertical impact peak (VIP), vertical instantaneous loading rate (VILR) and vertical average loading rate (VALR). We found that there were significant differences in lower extremity loading variables among 5 step frequency conditions. Furthermore, quadratic regression analyses revealed that the minimum loading variable frequencies were 17.25, 17.55, and 18.07% of preferred step frequency for VIP, VILR and VIAR, respectively. Thus, adopting a step frequency greater than one's preferred may be practical in reducing the risk of developing a tibial stress fracture by decreasing lower extremity loading variables., (© Georg Thieme Verlag KG Stuttgart · New York.)

Pedestrian protection is one of the key topics for safety measures in traffic accidents all over the world. To analyze the relation between the collision site of the vehicle bumper and the severity of the lower extremity injuries, we performed biomechanical experiments. We compared the applied external force and the risks of subsequent injuries between the impact of the center and side positions of the front bumper. These comparisons were performed by practical impact tests with eight typical different types of cars which were typical of the current vehicle fleets. The tests were made using the TRL legform impactor which was a mechanical substitute of a pedestrian lower extremity. The TRL impactor is used all over the world for assessing the safety of car bumpers. It was found that the risks of lower extremity injuries in the impacts at the side positions, in front of the vehicle's side member, were significantly higher than those at the center. In the tests, we found that foam materials around the rigid front cross member had a significant effect on reducing the lower extremity injury risks and especially tibia fracture risk against vehicle bumper center collisions, but had little effect at the sides of the bumper over the vehicle's side members where the foam was thinner. We also found that the front shape of the vehicle affected the risk of ligaments injuries. According to these results, the information of impact locations of cars in vehicle-to-pedestrian traffic accidents is valuable for clinicians to diagnose patients with lower extremity injuries in traffic accidents and for forensic pathologists to analyze the accident reconstruction. Furthermore, the results suggest that testing of the bumper area in front of the main longitudinal beams should be included in the car safety legislation to require pedestrian safety., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

We investigated the fracture-free survival of long bones stabilised by a telescopic intramedullary rod (TIMR) in patients with osteogenesis imperfecta with respect to the remodelling status of fracture or osteotomy sites and TIMR regions, in order to identify risk factors for fracture. A total of 44 femora and 28 tibiae in 25 patients with a mean age of 5.0 years (1.9 to 10.5) at presentation were studied. There were six patients with Sillence type I, five with type III, 13 with type IV and one with type V osteogenesis imperfecta. All received bisphosphonate treatment at the same stage during the mean follow-up of 7.3 years (0.5 to 18.1). The fracture-free survival was estimated at 6.2 years (95% confidence interval 5.1 to 7.3) by Kaplan-Meier analysis. More than half the fracture or osteotomy sites remained in a less-remodelled state at the latest follow-up or time of fracture. Of the 33 fractures, 29 (87.9%) occurred in long bones containing a less-remodelled site, and these fractures were located at this site. The relative fracture risk at the rod tip was significantly greater than in any other TIMR region (p < 0.001), and this was higher in bone segments having a less-remodelled site. This study shows a persistent fracture risk in TIMR-stabilised long bones, especially at less-remodelled fracture or osteotomy sites and at the rod tip.

Prophylactic internal fixation (PIF), with a bone plate in either the anterior (over the section defect) or posterior (on intact cortex) position, has substantially reduced the incidence of fracture at the donor site of the radial osteocutaneous free flap. This study uses the sheep tibia model to compare the effectiveness of new T-shaped titanium plates utilising a unilocking screw system with a 3.5 mm steel plate and bicortical screw fixation system commonly applied for PIF. Forty matched pairs of adult sheep tibias were tested in torsion and 4-point bending. An osteotomised bone was significantly weaker (p<0.001) than an intact bone in both bending and torsion with a mean loss of 77% and 64% of strength respectively. The tibia withstood much greater bending loads. All of the constructs significantly strengthened an osteotomised bone by a factor of 1.73-2.43 times in bending and 1.54-2.63 in torsion. The 2.4 mm T-plate in an anterior position (section) was the baseline against which other plates in differing positions were compared. The 3.5 mm T-plate section, DCP section and DCP cortex constructs had 41%, 30% and 2% greater mean bending strengths respectively but only the 3.5 mm T-plate section result approached statistical significance (p=0.06). In torsion the DCP section, 3.5 mm T-plate section and DCP cortex constructs had 56% (p=0.01), 27% (p=0.06) and 25% greater mean strengths respectively. When compared to an intact bone the mean bending strength restored by the DCP section (84%) and 3.5 mm T-plate section (87%) constructs was greatest and effectively restored the strength to that of an intact bone (100%). In torsion the mean strength restored by the DCP section (62%), DCP cortex (44%), 3.5 mm T-plate section (40%) and 2.4 mm T-plate (36%) remained significantly less than an intact bone. All of the plate constructs significantly strengthened an osteotomised bone but overall the 3.5 mm T-plate section and DCP section were the strongest constructs and most suitable for PIF. The lighter 2.4 mm T-shaped titanium plate was least effective. The strongest reinforcement in bending and torsion was the 3.5 mm T-plate section and DCP section respectively. The 3.5 mm DCP section plate was significantly stronger (p=0.01) than the 3.5 mm T-plate in torsion and remains the most effective construct for resisting torsional stresses, which are probably the commonest cause of fracture in clinical practice., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: tibial stress fractures, which are among the most common running related injuries, have been associated with increased lower extremity loading (i.e., peak positive acceleration of the tibia, vertical force impact peak, and average and instantaneous vertical force loading rates) during initial contact. This study was conducted to evaluate the efficacy of a gait retraining program designed to reduce this loading during running and to assess the short-term persistence of these reductions., Methods: ten runners (six females and four males) with peak positive tibial acceleration greater than 8g, measured in an initial screening, participated in the retraining program. During the retraining sessions, subjects ran on a treadmill and received real-time visual feedback from an accelerometer attached to their distal tibias. Tibial acceleration and vertical ground reaction force data were collected from subjects during overground data collection sessions held pre-training, post-training, and at a 1-month follow-up., Findings: peak positive acceleration of the tibia, vertical force impact peak, and average and instantaneous vertical force loading rates were all reduced immediately following the gait retraining. The decrease in tibial acceleration was nearly 50%. The reductions in vertical force loading rates and vertical force impact peak were approximately 30% and 20%, respectively. These reductions were maintained at the 1-month follow-up., Interpretation: subjects were able to run with reduced tibial acceleration and vertical force loading immediately following completion of the gait retraining program and at the 1-month follow-up evaluation. This may reduce their risk of stress fractures., (Published by Elsevier Ltd.)

Study Design: Single-subject with repeated measures., Objectives: To determine if runners can use real-time visual feedback from an accelerometer to achieve immediate reductions in tibial acceleration and vertical-force loading rates., Background: Stress fractures are a common injury among runners. Previous studies suggest that runners with higher than normal tibial acceleration and vertical-force loading rates are at increased risk for tibial stress fractures. If these runners can be trained to reduce the loading on their lower extremities, it may reduce their risk of stress fractures., Methods: Five subjects participated in this study. All subjects ran on a treadmill, instrumented with force transducers, during a single 30-minute session that was divided into warm-up, feedback, no-feedback, and cool-down periods. During running, the subjects also wore an accelerometer taped to their distal right tibia. Peak positive acceleration of the tibia, vertical force impact peak, and average and instantaneous vertical-force loading rates were assessed at the end of the warm-up, feedback, and no-feedback periods., Results: Single-subject analysis revealed that 4 of the 5 subjects had significant reductions in their peak positive acceleration at the end of the no-feedback period compared to the warm-up. In addition, all of the subjects had significant decreases in impact peak and vertical ground reaction force loading rates at the end of the no-feedback period., Conclusion: In a single session of training with real-time visual feedback, it appears that most runners can reduce the types of lower extremity loading associated with stress fractures. This may lead to training programs that reduce the risk of stress fractures for runners.

Leg disorders have become a major concern in comercial poutltry meat production. The mechanisms which cause leg problems are not completely understood. It has been hypothesed that high growth rate and low locomotor activity are the main factors. The particular effects of the different factors have been elucidated in special experiments. The locomotor activity of broilers with different growth rates has been observed in deep litter compartments with videotracking technique. The effects of locomotor activity were analysed through a training on treadmills in slow and fast growing broilers. Fast growing broilers showed a lower activity level from week one onwards and there was a pronounced drop in walking distances in the third week of age (21 to 8 meters per hour), while the slow growing broilers maintained a high activity level from 36 m throughout the fattening period. Systematic training of fast growing birds on treadmills increased the locomotion ability, the bone density and thickness and reduced the bending and twisting in leg bones. Increasing the distance between feeders and drinkers may be a method to increase locomotor activity under practical conditions and may be a method to reduce the incidence of leg disorders. Based on the results of previous experiments, a final test was carried out placing the feeder and drinker at two varied distances apart from each other (2 and 12 meters) and monitoring the effects on growth rate, locomotor activity, bone development and leg weakness in broilers. A total of 4800 male and female broilers (in groups of 600) were tested under virtually real conditions. The larger distance between food and water led to a three times increased level of locomotor activity. Weight development and food utilisation were not negatively influenced. Groups of birds, whose food and water supply were placed 12 metres apart, had significantly less cases of leg weakness and deaths due to leg disorders (2%). Increased walking activated the bone building processes of the tibia. This method is a practical way for broiler farmers to decrease leg weakness.

Background: Though the injury patterns of the lower extremities in skiing have changed since 1970, tibial fractures remain daily work of hospitals near ski slopes. A lot of medical studies have analysed the relevance of well adjusted bindings of the common lesions of the knee joint ligaments. However the influence of the flexibility of the ski boot and the injury pattern has been neglected., Material and Method: 49 tibial fractures have been analysed in a hospital near a large ski resort in the alpes. All fractures occurred during alpine skiing. The type of the fracture, according to the AO-classification and the injury pattern have been documented. Also demographic data, ski experience and specification concerning the ski boot have been questioned. The type of the ski boot and the grade of flexibility, have been documented if possible. It has also been recorded whether the binding opened., Results: In contrast to other studies our patients are represented in widely spread age-groups with a large share of elderly and experienced persons. Young or unexperienced sportsmen suffer primarily from fractures of the tibial diaphysis. With increasing skiing experience the injury pattern is widening on the whole leg. 62 % of all fractures are caused by rotation traumas. Compression, dorsal forces and direct collisions are the other causes. In 59 % of all accidents the binding failed to open. There is an increased risk of complex fractures in the proximal or distal epiphysis if the binding has not opened. 23 % of all fractures occurred with rented ski boots. Only 16 % of all ski boots are labelled with a flexibility index. There is no standardized value for the flexibility of ski boots. The trend can be derived that rigid ski boots with a high flexibility index cause above all fractures of the diaphysis. 10 % of all fractures happened to patients wearing "snowblades". These short skis without safety bindings contributed a considerable share to tibial fractures, even though there is no big leverage., Conclusion: Tibial fractures are still a frequent injury in alpine skiing. Increasing dynamics by means of improved material lead to enlarged forces on the lower extremity. Rotation forces are the major cause of tibial fractures. Therefore it is necessary to adjust the binding to the weight and abilities of the athlete. Also the appropriate choice of the right ski boot is essential. We recommend an internationally standardized marking regarding the flexibility of ski boots to enable the customers to compare the ski boots.

Background: Congenital anterolateral bowing of the tibia is a pre-pseudarthrosis stage of congenital pseudarthrosis of the tibia and is associated with a substantial risk of fracture and pseudarthrosis. We evaluated the results of prophylactic bypass grafting performed in combination with bracing to prevent fracture and pseudarthrosis., Methods: This retrospective series included ten patients with pre-pseudarthrosis of the tibia treated, between 1991 and 2002, with prophylactic bypass grafting with an allograft fibula placed posteromedially in a stress-bearing fashion. The average patient age was 2.3 years at the time of diagnosis, 3.6 years at the time of surgery, and ten years at the time of final follow-up. The mean duration of follow-up was seventy-eight months. Brace protection was recommended at the time of diagnosis and was continued after the operation until maturity. Despite the bracing, a low-energy fracture developed and partially healed prior to the bypass grafting in one patient. The remaining nine patients had no fractures prior to the bypass grafting. At the time of final follow-up, the patients were examined clinically and radiographically for the presence of a fracture or pseudarthrosis and for residual deformity, including malalignment, ankle and knee joint abnormalities, and leg length discrepancy., Results: No patient had either a fracture or a pseudarthrosis of the tibia at the time of follow-up. All grafts united to the tibia at both ends. Complications included an allograft fracture in three patients, which healed in all; allograft resorption in one patient; and pseudarthrosis of the ipsilateral host fibula in one patient. At the time of final follow-up, a mean of 9 mm (range, 0 to 37 mm) of leg length discrepancy was found. A corrective osteotomy was done for four patients (three because of ankle valgus and one because of diaphyseal deformity)., Conclusions: In this small series of ten patients with congenital anterolateral bowing of the tibia treated with bypass strut grafting and long-term bracing, there were no cases of pseudarthrosis of the tibia. Distal tibial deformity may persist throughout the growth period and require operative correction in patients treated with this procedure., Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Objective: To explore the effects of Bushen Jianpi Huoxue Recipe, a compound traditional Chinese herbal medicine for tonifying the kidney, invigorating the spleen and promoting blood circulation, on tibial stress injuries in rabbits., Methods: Thirty-five mature male rabbits were used in the experiment, and randomly divided into 7 groups: sedentary control (SC) group, 1-week exercise (E-1W) group, 2-week exercise (E-2W) group, 3-week exercise (E-3W) group, 4-week exercise (E-4W) group, 3-week exercise and 1-week Chinese herbal medicine treatment (EMT-1W) group, and 4-week exercise and 2-week Chinese herbal medicine treatment (EMT-2W) group. There were 5 rabbits in each group. A rabbit model of tibial stress injuries was established by stimulating the rabbits to jump and run within a high-voltage and low-current electronic cage. Radiologic features, bone scintigraphy, histology and electron microscopy of rabbit tibia were observed, and the content of blood parathyroid hormone (PTH), bone gla protein (BGP) and testosterone was detected by using radioimmunoassay method., Results: After 2-week exercise, changes in histology and osteocytes had a tendency towards stress injuries. Serum PTH and BGP levels were remarkably increased, while serum testosterone level was lower than that in the SC group. Three- and four-week continuous exercise resulted in tibial stress injuries, and the positive changes were observed in X-ray features and radionuclide images. Compared with E-3W group, the levels of serum BGP and testosterone were decreased remarkably. A series of positive results such as prevailing negativeness of X-ray features and radionuclide images, increasing process of osteogenesis, typical osteogenic phase of osteocytes and favorable transformation of biochemical markers was shown in EMT-1W and EMT-2W groups. It also showed remarkable rising levels of serum BGP and testosterone and remarkable reducing level of serum PTH in EMT-1W and EMT-2W groups as compared with E-1W and E-2W groups., Conclusion: Bushen Jianpi Huoxue Recipe can prevent and treat exercise-induced tibial stress injuries by stimulating new bone formation and increasing serum testosterone level.

Reference: Thacker SB, Gilchrist J, Stroup DF, Kimsey CD. The prevention of shin splints in sports: a systematic review of literature. Med Sci Sports Exerc. 2002;34(1):32-40., Clinical Question: Among physically active individuals, which medial tibial stress syndrome (MTSS) prevention methods are most effective to decrease injury rates?, Data Sources: Studies were identified by searching MEDLINE (1966-2000), Current Contents (1996-2000), Biomedical Collection (1993-1999), and Dissertation Abstracts. Reference lists of identified studies were searched manually until no further studies were identified. Experts in the field were contacted, including first authors of randomized controlled trials addressing prevention of MTSS. The Cochrane Collaboration (early stage of Cochrane Database of Systematic Reviews) was contacted., Study Selection: Inclusion criteria included randomized controlled trials or clinical trials comparing different MTSS prevention methods with control groups. Excluded were studies that did not provide primary research data or that addressed treatment and rehabilitation rather than prevention of incident MTSS., Data Extraction: A total of 199 citations were identified. Of these, 4 studies compared prevention methods for MTSS. Three reviewers independently scored the 4 studies. Reviewers were blinded to the authors' names and affiliations but not the results. Each study was evaluated independently for methodologic quality using a 100-point checklist. Final scores were averages of the 3 reviewers' scores., Main Results: Prevention methods studied were shock-absorbent insoles, foam heel pads, Achilles tendon stretching, footwear, and graduated running programs. No statistically significant results were noted for any of the prevention methods. Median quality scores ranged from 29 to 47, revealing flaws in design, control for bias, and statistical methods., Conclusions: No current evidence supports any single prevention method for MTSS. The most promising outcomes support the use of shock-absorbing insoles. Well-designed and controlled trials are critically needed to decrease the incidence of this common injury.

This study investigated the strengthening effect of different types of plate and position after osteotomy of the sheep tibia, which is a model for the radial osteocutaneous donor site. Fifty matched pairs of adult sheep tibias were tested in torsion and four-point bending. Firstly, the weakening effect of an osteotomy was compared with the intact bone. Then pairs of bones with an osteotomy were compared with and without reinforcement with different types of 3.5mm plate. The plate was placed in either the anterior (over the defect) or posterior (on the intact cortex) position. In torsion the mean strength of the intact bone was 45% greater than after osteotomy (P=0.02). The reinforced bone was on average 61% stronger than the unreinforced bone (P<0.001). In bending the mean strength of the intact bone was 188% greater than after osteotomy (P=0.02). The reinforced bone was on average 184% stronger then the unreinforced bone (P<0.001). The tibia was able to withstand much greater loads in bending. The dynamic compression plate was the strongest reinforcement in both torsion and bending. The position of the plate did not alter the strengthening effect in torsion but the posterior position resisted greater bending loads (P=0.01). This may not be relevant in clinical practice as the radius is likely to fracture first as a result of lower torsional forces.

Periprosthetic total knee arthroplasty fractures of the distal femur and proximal tibia can be among the most difficult complications to effectively manage within the realm of joint replacement. These fractures can occur intraoperatively or postoperatively. Intraoperative fractures can be avoided by early removal of hardware, use of stems for stress risers, and use of intraoperative radiographs whenever further visualization is required. Intraoperative fractures should be fixed and then protected by a stem and avoidance of weight bearing until healed. Postoperative fractures can occur with significant trauma, or minor injury when osteolysis is present. Operative management is almost always required. The method of treatment depends upon factors such as the stability of implant fixation, location of the fracture, quality of the bone, and presence or absence of an open-box femoral component.

Lateral tibial plateau fractures or lateral cortex fractures may occur when performing medial opening wedge osteotomy. Some special tools have been described to prevent lateral tibial plateau or lateral cortex fracture during the medial separation of the osteotomy planes in medial opening wedge osteotomy. The author has developed a distractor with angle-scale to prevent such complications. Between December 2001 and April 2004, 40 opening wedge osteotomies stabilised with the plate with wedge were performed on 38 patients. The distraction of initial osteotomies in 25 knees was done with different techniques and there were three lateral tibial plateau fractures and nine lateral cortex fractures. The remaining, recently operated, 15 knees were treated with the aid of the above described angle-scale distractor to prevent lateral tibial plateau and lateral cortex fractures. There was no lateral tibial plateau fractures during the surgery when we used this instrument for the distraction of the osteotomy sites. A subsequent prospective study evaluated this new device.

The treatment of anterolateral bowing with an intact tibia is directed toward prevention of the fracture and subsequent pseudoarthrosis. Patients with anterolateral bowing of the tibia are usually treated with an ankle-foot orthosis until the deformity is improved. There is no documentation that an orthosis can prevent the fracture or correct the deformity, and if the deformity is not corrected, it will result in different mechanical problems. In this study, 6 legs in 6 patients with anterolateral bowing of the tibia with a narrow sclerotic medullary canal (Crawford type II) were treated using Ilizarov's method. The average age was 6.8 years. All patients underwent correction of the anterolateral bowing by excision of the affected part. If the gap was less than 4 cm, acute shortening followed by bone lengthening was done. If the gap was more than 4 cm, bone transport was preferred. The mean duration of follow-up was 3.2 years. The anterolateral bowing was corrected in all patients. Complications such as pin track infection, premature consolidation and delayed union at the docking site were encountered. We believe that Ilizarov's method offers a more efficient solution for this type of deformity than prophylactic orthotic treatment or prophylactic bypass bone graft.

Periprosthetic fractures of the femur, tibia and patella are being registered with increasing frequency due to the rising numbers of total knee replacements. Depending on the site of the fracture, apart from mere traumatic mechanisms, implant specific parameters and implant loosening may represent the main causes of periprosthetic fracture. Moreover, general risk factors promote the manifestation of a periprosthetic fracture. Nowadays, valid classifications are available to categorize periprosthetic fractures of the femur, tibia and patella, and to create the basis for specific decision-making in choice of treatment. Despite a wide field of treatment options, the actual functional outcome after therapy and the high rates of complications imply that an adequate analysis of the fracture etiology and the corresponding transfer into an individualized treatment concept offer the chance of functional restoration of the patient similar to the pre-fracture state.