Introduction. The human body is a complex and continually adapting organism. It is theorised that the morphology of the proximal femur is closely related to that of the distal femur. Patients that have abnormal anatomy in the proximal femur, such as a high femoral neck anteversion angle, may have abnormal anatomy in the distal femur to overcome proximal differences. This phenomenon is of key interest when performing Total Hip Replacement (THR) or Total Knee Replacement (TKR) surgery. The current design and placement of existing hip and knee implants does not account for any correlation between the anatomical parameters of the proximal and distal femur, where bone anatomy may have adapted to compromise for abnormalities. A preliminary study of 21 patients has been carried out to assess the relationship between the proximal and distal femur. The difficulties in defining and measuring key anatomical parameters on the femur have been widely discussed in the literature [1] due to its complex three dimensional geometry. Using CT scans of healthy octogenarians, it was possible to mark key anatomical landmarks which could be used to define various anatomical axes throughout the femur. Correlation analyses could then be carried out on these parameters to assess the relationship between proximal and distal femur morphology. Methods. Each femur was initially realigned along the mechanical axis (MA); defined by joining the centre of the femoral head (FHC) to the centre of the intercondylar notch (INC) [2]. All anatomical landmarks were then identified using the Materialise Mimics v12 software (Figure 1 and 2) and exported into Microsoft Excel for analysis. Key anatomical parameters which were derived from these landmarks included the femoral neck axis (FNA), femoral neck anteversion angle (FNAA) [1–4], condylar twist angle, clinical transepicondylar axis (TEA), trochlea sulcus angle and medial and lateral trochlea twist. A correlation analysis was carried out on SPSS Statistics v20 (IBM) to assess the relationship between proximal and distal anatomical parameters. Results. The correlation analysis displayed a positive linear correlation between the FNAA and the clinical TEA (adjusted R squared = 0.471, p < 0.001) indicating that an abnormally high FNAA is correlated with a higher TEA angle (Figure 3). No strong relationship was found between the FNAA and the additional distal parameters compared, in particular there was no trend between the FNAA and the geometry of the trochlea as measured by the sulcus angle and trochlea twist. Discussion. The morphology of the distal femur seems to be at least partially correlated with the proximal femur and the relationship should be studied further to assess any potential effect on THA and TKA surgery. An extension of this study should assess an increased patient sample size and further anatomical parameters

Introduction. Infected big gap non-union of femur and tibia are difficult to treatment because of infection, bone loss, shortening, poor sift tissue over and deformity. Step by step management and definitive treatment by Ilizarov fixator was achieved in our cases. Materials and Methods. A long defect which is more than 10cm in femur and tibia because of infection and gap, tumor resection, traumatic loss, which is very difficult to treat by conventional method and that's why we treated that type defect by Tibialization of fibula with Ilizarov technique. Management of infected big gap non-union of the femur include debridement and bone transport by Ilizarov technique by using Ilizarov fixator we can correct deformities, regenerate new bone without bone grafting, correct LLD and patient can weight bear during the course of treatment. We retrospectively reviewed records of 246 consecutive patients who underwent distraction osteogenesis using Ilizarov compression-distraction device for infected big gap INU of femur and tibia from 2000 to 2020. Results. All healed with the application of Ilizarov fixator, 5 needed reapplications of Ilizarov to achieve 100% union. 210 were excellent, 25 good and 6 were fair by ASAMI criteria. Mean Ilizarov duration was 366 days (130–250). Mean 8.2 cm length was achieved in the regenerate. Conclusions. A well plan step by step Ilizarov technique to cover infected gap non-union of femur and tibia is an excellent method in challenging cases. Excellent results cannot be achieved with conventional methods but can be easily achieved with Ilizarov technique within 1–2 years

Aim. Repeat revision surgery of total hip or knee replacement may lead to massive bone loss of the femur. If these defects exceed a critical amount a stable fixation of a proximal or distal femur replacement may not be possible. In these extraordinary cases a total femur replacement (TFR) may be used as an option for limb salvage. In this retrospective study we examined complications, revision free survival (RFS), amputation free survival (AFS) and risk factors for decreased RFS and AFS following a TRF in cases of revision arthroplasty with a special focus on periprosthetic joint infection (PJI). Method. We included all implantations of a TFR in revision surgery from 2006–2018. Patients with a primary implantation of a TFR for oncological indications were not included. Complications were classified using the Henderson Classification. Primary endpoints were revision of the TFR or disarticulation of the hip. The minimum follow up was 24 month. RFS and AFS were analyzed using Kaplan-Meier method, patients´ medical history was analyzed for possible risk factors for decreased RFS and AFS. Results. After applying the inclusion criteria 58 cases of a TFR in revision surgery were included with a median follow-up of 48.5 month. The median age at surgery was 68 years and the median amount of prior surgeries was 3. A soft tissue failure (Henderson Type I) appeared in 16 cases (28%) of which 13 (22%) needed revision surgery. A PJI of the TFR (Henderson Type IV) appeared in 32 cases (55%) resulting in 18 (31%) removals of the TFR and implantation of a total femur spacer. Disarticulation of the hip following a therapy resistant PJI was performed in 17 cases (29%). The overall 2-year RFS was 36% (95% confidence interval(CI) 24–48%). Patients with a Body mass Index (BMI) >30kg/m² had a decreased RFS after 24 month (>30kg/m² 11% (95%CI 0–25%) vs. <30kg/m² 50% (95%CI 34–66%)p<0.01). The overall AFS after 5 years was 68% (95%CI 54–83%). A PJI of the TFR and a BMI >30kg/m² was significantly correlated with a lower 5-year AFS (PJI 46% (95%CI 27–66%) vs no PJI 100%p<0.001) (BMI >30kg/m² 30% (95% KI 3–57%) vs. <30km/m² 85% (95% KI 73–98%)p<0.01). Conclusions. A TFR in revision arthroplasty is a valuable option for limb salvage but complications in need of further revision surgery are common. Patients with a BMI >30kg/m² should be informed regarding the increased risk for revision surgery and loss of extremity before operation

Introduction. Fully implantable systems are used commonly only after maturity. What are indications to use fully implantable systems at the femur even in children?. Materials and Methods. Implantable lengthening nails (FITBONE) were used retrograde at the femur in minimal invasive technique to correct a limb length discrepancy of >6 cm. In 5 cases a relevant deformity was corrected in the same surgery. In all cases a final step of lengthening was planned at the femur and at the tibia with fully implantable devices at maturity. Results. 18 patients with the medium age of 10,3 years (8–14) were treated. In 17 cases the goal of lengthening was achieved without any complication. In one case of proximal femoral deficiency lengthening had to be stopped because of increasing tendency of knee joint luxation. Bone formation occurred circular around the nail in all cases. Full load bearing was possible in the average after 2,2 days/mm. No technical problems occur. In one case induced deformity in the lateral plane was observed which was corrected at the final step. At the end of treatment functional and cosmetical result was perfect in all cases. Conclusions. Fully implantable motorized distraction nails are a favorable option for lengthening and deformity correction of the femur even for children older than 10 years to correct limb length discrepancy of more than 6 cm. The treatment has a low pain level, is comfortable and nearly no scars are visible

Gunshot-induced fractures of the proximal femur typically present with severe comminution and bone loss. These fractures may also be associated with local damage to soft tissue, neurovascular structures and injuries to abdominal organs. The aim was to evaluate the outcomes of civilian gunshot injuries to the proximal femur at a major trauma center in South Africa. A retrospective review of all patients who sustained gunshot-induced proximal femur fractures between January 2014 and December 2017 was performed. Patients with gunshot injuries involving the hip joint, neck of femur or pertrochanteric fractures were included. Patient demographics, clinical- treatment and outcome data were collected. Results are reported as appropriate given the distribution of continuous data or as frequencies and counts. Our study included 78 patients who sustained 79 gunshot-induced proximal femur fractures. The mean age of patients was 31 ± 112, and the majority of patients were male (93.6%). Pertrochantenteric fractures were the most common injuries encountered (73.4%). Treatment included cephalomedullary nail (60.8%), arthrotomy and internal fixation (16.4%) and interfragmentary fixation with cannulated screws (6%). One case of complete neck of femur fracture had fixation failure, which required conversion to total hip arthroplasty. The overall union rate was 69.6%, and 6.3% of patients developed a fracture-related infection in cases who completed follow-up. The study shows an acceptable union rate when managing these fractures and a low risk of infection. As challenging as they are, individual approaches for each fracture and managing each fracture according to their merits yield acceptable outcomes

Introduction. The use of vascularised fibula grafts is an accepted method for reconstructing the distal femur following resection of malignant childhood tumours. Limitations relate to the mismatch of the cross-sectional area of the transplanted fibula graft and thel ocal bone, instability of the construct and union difficulties. We present midterm results of a unique staged technique—an immediate defect reconstruction using a double-barrel vascularised fibula graft set in in A-frame configuration and a subsequent intramedullary femoral lengthening. Materials & Methods. We retrospectively included 10 patients (mean age 10 y)with an osteosarcoma of the distal femur, who were treated ac-cording to the above-mentioned surgical technique. All patients were evaluated with regards to consolidation of the transplanted grafts, hypertrophy at the graft-host junctions, leg length discrepancies, lengthening indices, complications as well as functional outcome. Results. The mean defect size after tumour resection was 14.5 cm, the mean length of the harvested fibula graft 22 cm, resulting in a mean (acute) shortening of 4.7 cm (in 8 patients). Consolidation was achieved in all cases, 4 patients required supplementary bone grafting. Hypertrophy at the graft-host junctions was observed in78% of the evaluable junctions. In total 11 intramedullary lengthening procedures in 9 patients had been performed at the last follow up. The mean Muskuloskeletal Society Rating Scale(MSTS) score of the evaluable 9 patients was 85% (57% to 100%)with good or excellent results in 7 patients. Conclusions. A-frame vascularised fibula reconstructions showed encouraging results with respect to defect reconstruction, length as well as function and should therefore be considered a valuable option for reconstruction of the distal femur after osteosarcoma resection. The surgical implementation is demanding though, which is emphasized by the considerable high number of com-plications requiring surgical intervention, even though most were not serious

Resection of the proximal femur raises several challenges to the orthopedic oncology surgeon. Among these is the re-establishment of the abductor mechanism that might impacts on hip function. Extent of tumor resection and surgeons’ preferences dictate the reconstruction method of the abductors. While some surgeons advocate the necessity of greater trochanter (GT) preservation whenever possible, others attempt direct soft tissues reattachment to the prosthesis. Sparse data in the literature evaluated the outcomes of greater trochanter fixation to the proximal femur megaprosthesis. This is a retrospective monocentric study. All patients who received a proximal femoral replacement after tumor resection between 2005 and 2021 with a minimum follow-up of three months were included. Patients were divided into two groups: (1) those with preserved GT reattached to the megaprosthesis and (2) those with direct or indirect (tenodesis to fascia lata) abductor muscles reattachment. Both groups were compared for surgical outcomes (dislocation and revision rates) and functional outcomes (Trendelenburg gait, use of walking-assistive device and abductor muscle strength). Additionally patients in group 1 were subdivided into patients who received GT reinsertion using a grip and cables and those who got direct GT reinsertion using suture materials and studied for GT displacement at three, six and 12 months. Time to cable rupture was recorded and analyzed through a survival analysis. Fifty-six patients were included in this study with a mean follow-up of 45 months (3-180). There were 23 patients with reinserted GT (group 1) and 33 patients with soft tissue repair (group 2). Revision rate was comparable between both groups(p=0.23); however, there were more dislocations in group 2 (0/23 vs 6/33; p=0.037). Functional outcomes were comparable, with 78% of patients in group 1 (18/23) and 73% of patients in group 2 (24/33) that displayed a Trendelenburg gait (p=0.76). In group 1, 70% (16/23) used walking aids compared to 79% of group 2 (27/33) (p=0.34). Mean abductor strength reached 2.7 in group 1 compared to 2.3 in group 2 (p=0.06). In group 1, 16 of the 23 patients had GT reinsertion with grip and cables. Median survival of cables for these 16 patients reached 13 months in our series. GT displacement reached a mean of two mm, three mm, and 11 mm respectively at three, six and 12 months of follow-up in patients with grip and cables compared to 12 mm, 24 mm and 26 mm respectively at the same follow-up intervals in patients with GT stand-alone suture reinsertion(p<0.05). Although GT preservation and reinsertion did not improve functional outcomes after proximal femur resection and reconstruction with a megaprosthesis, it was significantly associated with lower dislocation rate despite frequent cable failure and secondary GT migration. No cable or grip revision or removal was recorded. Significantly less displacement was observed in patients for whom GT reattachment used plate and cables rather than sutures only. Therefore we suggest that GT should be preserved and reattached whenever possible and that GT reinsertion benefits from strong materials such as grip and cables

Dual plating of the medial and lateral distal femur has been proposed to reduce angular malunion and hardware failure secondary to delayed union or nonunion. This strategy improves the strength and alignment of the construct, but it may compromise the vascularity of the distal femur paradoxically impairing healing. This study investigates the effect of dual plating versus single plating on the perfusion of the distal femur. Ten matched pairs of fresh-frozen cadaveric lower extremities were assigned to either isolated lateral plating or dual plating of a single limb. The contralateral lower extremity was used as a matched control. A distal femoral locking plate was applied to the lateral side of ten legs using a standard sub-vastus approach. Five femurs had an additional 3.5mm reconstruction plate applied to the medial aspect of the distal femur using a medial sub-vastus approach. The superficial femoral artery and the profunda femoris were cannulated at the level of the femoral head. Gadolinium MRI contrast solution (3:1 gadolinium to saline ration) was injected through the arterial cannula. High resolution fat-suppressed 3D gradient echo sequences were completed both with and without gadolinium contrast. Intra-osseous contributions were quantified within a standardized region of interest (ROI) using customized IDL 6.4 software (Exelis, Boulder, CO). Perfusion of the distal femur was assessed in six different zones. The signal intensity on MRI was then quantified in the distal femur and comparison was made between the experimental plated limb and the contralateral, control limb. Following completion of the MRI protocol, the specimens were injected with latex medium and the extra-osseous vasculature was dissected. Quantitative MRI revealed that application of the lateral distal femoral locking plate reduced the perfusion of the distal femur by 21.7%. Within the dual plating group there was a reduction in perfusion by 24%. There was no significant difference in the perfusion between the isolated lateral plate and the dual plating groups. There were no regional differences in perfusion between the epiphyseal, metaphyseal or meta-diaphyseal regions. Specimen dissection in both plating groups revealed complete destruction of any periosteal vessels that ran underneath either the medial or lateral plates. Multiple small vessels enter the posterior condyles off both superior medial and lateral geniculate arteries and were preserved in all specimens. Furthermore, there was retrograde flow to the distal most aspect of the condyles medially and laterally via the inferior geniculate arteries. The medial vascular pedicle was proximal to the medial plate in all the dual plated specimens and was not disrupted by the medial sub-vastus approach in any specimens. Fixation of the distal femur via a lateral sub-vastus approach and application of a lateral locking plate results in a 21% reduction in perfusion to the distal femur. The addition of a medial 3.5mm reconstruction plate does not significantly compromise the vascularity of the distal femur. The majority of the vascular insult secondary to open reduction, internal fixation of the distal femur occurs with application of the lateral locking plate

Introduction. Correction of multiplanar bone deformities in children is indicated for prevention of secondary orthopaedic complications. Different problems related to surgical intervention were reported: non-union, delayed union, recurrent deformity, refracture, nerve palsy and pin tract infection. The aim of this study was to show the results of children femur and tibia bowing deformities by Ilizarov technique. Materials and Methods. We analysed 27 cases of children femur and tibia bowing deformities under the age of 13 yrs. Simultaneous deformity correction in femur and tibia was done with Ilizarov device in ipsilateral side. Contralateral side was operated after 14 days. Results. The duration of Ilizarov fixation was 130 days on an average. The deformity correction was achieved with a proper alignment in all the cases. Conclusions. Bowing of femur and tibia can be corrected simultaneously by Ilizarov fixation with minimum complications. There were no recurrent deformities in our cases

Aim. Decubitus ulcers are found in approximately 4.7% of hospitalized patients, with a higher prevalence (up to 30%) among those with spinal cord injuries. These ulcers are often associated with hip septic arthritis and/or osteomyelitis involving the femur. Girdlestone resection arthroplasty is a surgical technique used to remove affected proximal femur and acetabular tissues, resulting in a substantial defect. The vastus lateralis flap has been employed as an effective option for managing this dead space. The aim of this study was to evaluate the long-term outcomes of this procedure in a consecutive series of patients. Method. A retrospective single-center study was conducted from October 2012 to December 2022, involving 7 patients with spinal cord injuries affected by chronic severe septic hip arthritis and/or femoral head septic necrosis as a consequence of decubitus ulcers over trochanter area. All patients underwent treatment using a multidisciplinary approach by the same surgical team (orthopedic and plastic surgeons) along with infectious disease specialists. The treatment consisted of a one-stage procedure combining Girdlestone resection arthroplasty with unilateral vastus lateralis flap reconstruction, alongside targeted antibiotic therapy. Complications and postoperative outcomes were assessed and recorded. The mean follow-up period was 8 years (range 2-12). Results. Of the 7 patients, 5 were male and 2 were female, with a mean age of 50.3 years at the time of surgery. Minor wound dehiscence occurred in 28.6% of the flap sites, and 2 patients required additional revisional procedures—one for hematoma and the other for bleeding. There were no instances of flap failure, and complete wound healing was achieved in an average of 32 days (range 20-41), with the ability to load over the hip area. No cases of infection recurrence or relapse were observed. Conclusions. An aggressive surgical approach is strongly recommended for managing chronic hip septic arthritis or proximal femur osteomyelitis in patients with spinal cord injuries. A single-stage procedure combining Girdlestone resection arthroplasty with immediate vastus lateralis muscle flap reconstruction proves to be an effective strategy for dead space management and localized antibiotic delivery through the vastus muscle, giving reliable soft tissue coverage around the proximal femur to avoid the recurrence of pressure ulcers. The implementation of a standardized multidisciplinary protocol contributes significantly to the success of reconstruction efforts

Aim. Differentiation of infected (INF) nonunion from aseptic (AS) nonunion is crucial for the choice of intra- and postoperative treatment. Preoperative diagnosis of infected nonunion is challenging, especially in case of low-grade infection lacking clinical signs of infection. Standard blood markers such as C-reactive protein or leucocyte count do not aid in preoperative diagnosis. Proteomic profiling has shown promising results for differentiation of numerous chronic disease states, and in this study was applied to preoperative blood samples of patients with nonunion in an attempt to identify potential biomarkers. Method. This prospective multicenter study enrolled patients undergoing revision surgery of femur or tibia nonunion. Patients with implant removal after regular fracture healing (HEAL) were included as a control-group. Preoperative blood samples, intraoperative tissue samples, sonication of osteosynthesis material and 1-year-follow-up questionnaire were taken. Nonunion patients were grouped into INF or AS after assessing bacterial culture and histopathology of retrieved samples. Diagnosis of infection followed the fracture related infection consensus group criteria, with additional consideration of healing one year after revision surgery. Targeted proteomics was used to investigate a predefined panel of 45 cytokines in preoperative blood samples. Statistical differences were calculated with Kruskal Wallis and Dunn's post hoc test. Cytokines with less than 80% of samples being above the lower limit of detection range (LLDR) were excluded for this study. Results. We recruited 62 AS, 43 INF and 32 HEAL patients. Patients in the two nonunion groups (INF and AS) did not differ concerning smoking, diabetes or initial open or closed fracture. Thirty-two cytokines were above LLDR in >80% of patients. INF patients showed a significant difference in expression of 8 cytokines compared to AS, with greatest differences observed for Macrophage Colony Stimulating Factor 1 (MCSF-1) and Hepatocyte Growth Factor (HGF) (p<0.01). In comparing AS with HEAL patients, 9 cytokines displayed significant differences, including interleukin (IL)-6, Vascular Endothelial Growth Factor A (VEGFA), Matrix Metalloproteinase 1 (MMP-1). Comparison of INF with HEAL patients revealed significantly different expression of 20 cytokines, including. IL-6, IL-18, VEGFA or MMP-1. Conclusions. Our study revealed differences in plasma cytokine profile of blood samples from INF and AS patients. Although no single biomarker is sufficient to differentiate these patients preoperatively in isolation, future multivariant analysis of this cytokine data in combination with clinical characteristics may provide valuable diagnostic insights. Funded by German Social Accident Insurance (FF-FR 0276) and AO Trauma (AR2021_04)

INTRODUCTION. The magnitude of principal strain is indicative of the risks of femoral fracture,. 1,2. while changes in femoral strain energy density (SED) after total hip arthroplasty (THA) have been associated with bone remodeling stimulus. 3. Although previous modeling studies have evaluated femoral strains in the intact and implanted femur under walking loads through successfully predicting physiological hip contact force and femoral muscle forces,. 1,2,3. strains during ‘high load’ activities of daily living have not typically been evaluated. Hence, the objective of this study was to compare femoral strain between the intact and the THA implanted femur under peak loads during simulated walking, stair descent, and stumbling. METHODS. CTs of three cadaveric specimens were used to develop finite element (FE) models of intact and implanted femurs. Implanted models included a commercially-available femoral stem (DePuy Synthes, Warsaw, IN, USA). Young's moduli of the composite bony materials were interpolated from Hounsfield units using a CT phantom and established relationships. 4. Peak hip contact force and femoral muscle forces during walking and stair descent were calculated using a lower extremity musculoskeletal model. 5. and applied to the femur FE models (Fig. 1). While maintaining the peak hip contact forces, muscle forces were further adjusted using an iterative optimization approach in FE models to reduce the femur deflection to the reported physiological range (< 5 mm). 2. Femoral muscle forces during stumbling were estimated utilizing the same optimization approach with literature-reported hip contact forces as input. 6. Maximum and minimum principal strains were calculated for each loading scenario. Changes in SED between intact and THA models were calculated in bony elements around the stem. RESULTS. As expected, high loads during stumbling resulted in the highest peak principal strains along femoral diaphysis (THA: 3179±523 and −4559±629 με; intact: 4232±818 and −5853±204 με) compared to stair descent and typically evaluated gait loads (THA: 1741±363 and −1893±76 με; intact: 2256±887 and −2509±493 με; Fig. 2). Principal strains in THA models peaked close to the tip of the femoral stem across three activities, compared with proximally located peak principal strains in the intact models (Fig. 2). Bony elements located medially and laterally to the femoral stem showed decreased SED after THA, while increased SED was observed in elements distal to the femoral stem (Fig. 3). DISCUSSION. Using appropriately distributed muscle forces, our model predicted similar peak principal strains and SED differences compared with reported values during walking (peak principal strains: ±1500 to ±2000 με. 1,2. ; SED differences: ± 0.02 MPa. 3. ). In addition to the close to failure level principal strains, stumbling showed the most noticeable changes in SED compared with the other two activities. Results suggest iterative bone remodeling simulations should include a composite of activities-of-daily-living loading conditions as well as appropriately distributed muscle forces. For any figures or tables, please contact authors directly

Advances in cancer therapy have prolonged patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in longer survival, preserved mobility, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The ideal clinical decision support tool will be of the highest sensitivity and specificity, non-invasive, generalizable to all patients, and not a burden on hospital resources or the patient's time. Our research uses novel machine learning techniques to develop a model to fill this considerable gap in the treatment pathway of MBD of the femur. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data of consecutive MBD patients presenting from 2009–2016. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 546 patients comprising 114 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray and clinical data including patient demographics, Mirel's criteria, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. We have trained a convolutional neural network (CNN) with AP X-ray images of 546 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. The model converges on two fully connected deep neural network layers that output the risk of fracture. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections, until overall prediction accuracy is optimized. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across five test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a model's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Our model achieved 88.2% accuracy in predicting fracture risk across five-fold cross validation testing. The F1 statistic is 0.87. This is the first reported application of convolutional neural networks, a machine learning algorithm, to this important Orthopaedic problem. Our neural network model was able to achieve reasonable accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to externally validate this algorithm on an international cohort

Advances in cancer therapy have prolonged cancer patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in patients more likely to walk after surgery, longer survival, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data for MBD patients (2009–2016) in order to determine which features are most commonly associated with fracture. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 1146 patients comprising 224 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray. The clinical data includes patient demographics, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. Each of Mirel's criteria has been further subdivided and recorded for each lesion. We have trained a convolutional neural network (CNN) with X-ray images of 1146 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. This model converges on two fully connected deep neural network layers that output the fracture risk. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a test's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Five-fold cross validation testing of our fully trained model revealed accurate classification for 88.2% of patients with metastatic bone disease of the proximal femur. The F1 statistic is 0.87. This represents a 24% error reduction from using Mirel's criteria alone to classify the risk of fracture in this cohort. This is the first reported application of convolutional neural networks, a machine learning algorithm, to an important Orthopaedic problem. Our neural network model was able to achieve impressive accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to validate this algorithm on an external cohort

Introduction. The posterior condylar axis of the knee is the most common reference for femoral anteversion. However, the posterior condyles, nor the transepicondylar axis, provide a functional description of femoral anteversion, and their appropriateness as the ideal reference has been questioned. In a natural standing positon, the femur can be internally or externally rotated, altering the functional anteversion of the native femoral neck or prosthetic stem. Uemura et al. found that the femur internally rotates by 0.4° as femoral anteversion increases every 1°. The aim of this study was to assess the relationship between femoral anteversion and the axial rotation of the femur before and after total hip replacement (THR). Method. Fifty-nine patients had a pre-operative CT scan as part of their routine planning for THR. The patients were asked to lie in a comfortable position in the CT scanner. The internal/external rotation of the femur, described as the angle between the posterior condyles and the CT coronal plane, was measured. The native femoral neck anteversion, relative to the posterior condyles, was also determined. Identical measurements were performed at one-week post-op using the same CT methodology. The relationship between femoral IR/ER and femoral anteversion was studied pre- and post-op. Additionally, the effect of changing anteversion on the axial rotation of the femur was investigated. Results. There was a strong correlation between axial rotation of the femur and femoral anteversion, both pre-and post-operatively. Pearson correlation coefficients of 0.64 and 0.66 respectively. This supported Uemura et al.'s findings that internal rotation of the femur increases with increasing anteversion. Additionally, there was a moderate correlation, r = 0.56, between the change in axial rotation of the femur and change in anteversion. This trend suggested that external rotation of the leg would increase, if stem anteversion was decreased from the native. Conclusions. Patients with high femoral anteversion may have a natural mechanism of “correction” with femoral internal rotation. Equally, patients with femoral retroversion tend to naturally externally rotate their leg. Decreasing stem anteversion from native, trended toward an increase in external rotation of the femur. This finding is supported by the clinical observation of patients with high anteversion and compensatory in-toe, who have normal foot progression angle post-operatively after having their anteversion decreased. These findings have implications when planning implant alignment in THR

Introduction. IM (Intra Medullary) nail fixation is the standard treatment for diaphyseal femur fractures and also for certain types of proximal and distal femur fractures. Despite the advances in the tribology for the same, cases of failed IM nail fixation continue to be encountered routinely in clinical practice. Common causes are poor alignment or reduction, insufficient fixation and eventual implant fatigue and failure. This study was devised to study such patients presenting to our practice and develop a predictive model for eventual failure. Materials and Methods. 57 patients who presented with failure of IM nail fixation (± infection) between Jan 2011 – Jun 2020 were included in the study and hospital records and imaging reviewed. Those fixed with any other kinds of metalwork were excluded. Classification for failure of IM nails – Type 1: Failure with loss of contact of lag screw threads in the head due to backing out and then rotational instability, Type 2A: Failure of the nail at the nail and lag screw junction, Type 2B: Failure of the screws at the nail lag screw junction, Type 3: Loosening at the distal locking sites with or without infection. X-rays reviewed and causes/site of failure noted. Results. Total patients - 57. Demography - Average age - 58.9 years, 22 Males and 35 females. Eleven patients were noted to have an infection at the fracture site that needed oral or IV antibiotics.16 patients - at least 1 cerclage wire for fracture reduction and fixation + IM Nail. Subtrochanteric fractures (42/57) were the most common to fail. In those fractures with postero-medial comminution, locking of the lag screw in position thus preventing backout can prevent failure. In type 2 failures, preventing varus fixation by early open reduction and temporary fixation with plates and screws can achieve improved results. Those with type 3 failures with periosteal reaction should be considered to be infected until proven otherwise. Conclusions. This classification for failure of IM nails in the femur can be used as a predictive model for failures and allow early recognition and intervention to tackle them

INTRODUCTION. Over the past 40 years of knee arthroplasty, significant advances have been made in the design of knee implants, resulting in high patient satisfaction. Patellar tracking has been central to improving the patient experience, with modern designs including an optimized Q-angle, deepened trochlear groove, and thin anterior flange.[1–4] Though many of today's femoral components are specific for the left and right sides, Total Joint Orthopedics’ (TJO) Klassic® Knee System features a universal design to achieve operating room efficiencies while providing all the advancements of a modern knee. The Klassic Femur achieves this through a patented double Q-angle to provide excellent patellar tracking whether implanted in the left or the right knee (Figure 1). The present study examines a prospective cohort of 145 consecutive TKA's performed using a modern universal femur and considers patients’ pre- and post-operative Knee Society Clinical Rating System score (KSS). METHODS AND MATERIALS. 145 primary total knee arthroplasties (TKA) were performed during the study using a measured resection technique with a slope-matching tibial cut for all patients. The posterior cruciate ligament (PCL) was sacrificed to accommodate an ultra-congruent polyethylene insert. The distal femur was cut at five degrees (5°) valgus; the tibia was resected neutral (0°) alignment for valgus legs and in two degrees (2°) of varus for varus alignment. The patella was resurfaced for all patients. Patients were followed annually for up to 46 months and were evaluated using the KSS score on a 200-point scale. RESULTS. The final study group comprised 127 primary TKAs. The average age was 68 years (51–90) with 45 males and 68 females. The average weight was 110kg (range: 75–151kg) for men and 88kg (range: 50–129kg) for women. One patient deceased during the follow-up period, four required manipulation under anesthesia, and two required revision for periprosthetic joint infection. There were no failures due to patellar maltracking. No special soft tissue releases were required in any patient. Average pre-operative knee score was 107, improving to 182 at average follow-up of 41 months (36–46 months). Results are summarized in Table 1. DISCUSSION. The improvement in patient clinical experience demonstrates that a universal femoral design can achieve excellent results if it incorporates modern technologies. A double Q-angle design with a deepened trochlear groove and a thin anterior flange appears to provide excellent patellar tracking for all patients in this cohort. This study is limited to the experience of a single institution. Further study would improve the extensibility of these findings. It does show, however, that a femur using a universal design with modern patellar tracking can improve patient satisfaction with their knee following TKA. For any figures or tables, please contact the authors directly

Femoral shaft fractures are fairly common injuries in paediatric age group. The treatment protocols are clear in patients of age less than 4 years and greater than 6 years. The real dilemma lies in the age group of 4–6 years. The aim of this study is to find whether a conservative line should be followed, or a more aggressive surgical intervention can provide significantly better results in these injuries. This study was conducted in a tertiary care hospital in Bhubaneswar, India from January 2020 to March 2021. A total of 40 patients with femur shaft fractures were included and randomly divided in two treatment groups. Group A were treated with a TENS nail while group B were treated with skin traction followed by spica cast. They were regularly followed up with clinical and radiological examination to look out for signs of healing and any complications. TENS was removed at 4–9 months’ time in all Group A patients. Group A patients had a statistically significant less hospital stay, immobilisation period, time to full weight bearing and radiological union. Rotational malunions were significantly lower in Group A (p-value 0.0379) while there was no statistically significant difference in angular malunion in coronal and sagittal plane at final follow up. Complications unique to group A were skin necrosis and infection. We conclude that TENS is better modality for treatment of shaft of femur fractures in patients of 4–6 years age as they significantly reduce the hospital stay, immobilization period and rotational malalignment

Objectives. Open fracture classification systems are limited in their use. Our objective was to classify open tibia and femur fractures using the OTS classification system in a region with high incidence of gunshot fractures. One hundred and thirty-seven patients with diaphyseal tibia and femur open fractures were identified from a prospectively collected cohort of patients. This database contained all cases (closed and open fractures) of tibial and femoral intramedullary nailed patients older than 18 years old during the period of September 2017 to May 2021. Exclusion criteria included closed fractures, non-viable limbs, open fractures > 48 hours to first surgical debridement and patients unable to follow up over a period of 12 months (a total of 24). Open fractures captured and classified in the HOST study using the Gustilo-Anderson classification, were reviewed and reclassified using the OTS open fracture classification system, analysing gunshot fractures in particular. Ninety percent were males with a mean age of 34. Most common mechanism was civilian gunshot wounds (gsw) in 54.7% of cases. In 52.6% of cases soft tissue management was healing via secondary intention, these not encompassed in the classification. Fracture classification was OTS Simple in 23.4%, Complex B in 24.1% and 52.6% of cases unclassified. The OTS classification system was not comprehensive in the classification of open tibia and femur fractures in a setting of high incidence of gunshot fractures. An amendment has been proposed to alter acute management to appropriate wound care and to subcategorise Simple into A and B subdivisions; no soft tissue intervention and primary closure respectively. This will render the OTS classification system more inclusive to all open fractures of all causes with the potential to better guide patient care and clinical research

Introduction. The aim of this radiographic study was to define the anatomical axis joint centre distance (aJCD) and anatomical axis joint centre ratio (aJCR) of the distal femur in the coronal plane for skeletally mature individuals. Materials and Methods. A cross-sectional radiographic study was conducted to calculate the horizontal distances between the anatomical axis and the centre of the knee at the level of the intercondylar notch and the joint line. Ratios relating these points to the width of the femur were then calculated. Results. A total of 164 radiographs were included: 91 male (55.5%) and 73 female patients (44.5%) with a mean age of 44.9 ± 18.0 years, with 79 right (48.2%) and 85 left (51.8%). The intercondylar width mean was 75.4 ± 6.8mm, the median aJCD at the notch was 3.6mm (interquartile range, IQR 2.1 – 5.1), the median aJCD at the joint line was 4.7mm (IQR 3.5 – 6.3), the aJCR at the notch 45.1 ± 2.7, and the aJCR at the joint line 43.5 ± 2.7. The intercondylar width was significantly different (p<0.001) between males (79.5 ± 5.0 mm) and females (70.4 ± 5.1 mm). A significant difference between the aJCR at the notch (p=0.003) and the aJCR at the joint line (p=0.002) was observed in males and females. No differences between the aJCD at the notch or aJCD at the joint line was observed between males versus females, left versus right and those younger versus those older than 65 years. Conclusions. This is the first objective description of the anatomic axis joint centre ratio (aJCR) of the distal femur in the coronal plane. This ratio can be used to aid the planning and execution of distal femoral deformity correction, retrograde femoral nailing, and total knee arthroplasty