Search

The purpose was to examine (1) the effect of measurement position and sex on femoral cartilage outcomes, and (2) the association between gait biomechanics and cartilage outcomes. Fifty individuals participated (25 males and 25 females; age = 20.62 [1.80] y). Ultrasound measured femoral cartilage thickness and echo-intensity at 90°, 115°, and 140° of knee flexion. Gait outcomes included the external knee adduction and knee flexion moments. Cartilage outcomes were compared using 2 (sex) × 3 (position) repeated-measures analysis of variance. Gait and cartilage associations were assessed using stepwise regression. Medial cartilage was thicker when measured at 90° compared with 115° (P =.02) and 140° (P <.01), and 115° compared with 140°, (P <.01) in males but not in females. Cartilage was thicker at 90° compared with 140° across both sexes within all regions (P <.01). Males had thicker cartilage than females in all positions (P <.01). Echo-intensity was lower at 90° than 115° (P <.01) and 140° (P =.01) in the central and lower at 90° than at 115° (P <.01) and 140° (P =.03) in lateral regions. No association was found between gait and cartilage outcomes. Ultrasound imaging position effects cartilage features more in males compared with females. Imaging position and sex influence cartilage outcomes and should be considered in study designs and clinical evaluation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of continuous perioperative clopidogrel treatment on the osseointegration of titanium implants. Materials and Methods: A total of 32 New Zealand rabbits were randomly divided between two groups: a clopidogrel group (n = 16) and a control group (n = 16). For 1 week prior to the surgical placement of a titanium implant in their medial femoral condyle, rabbits in the clopidogrel group received 3 mg/kg of clopidogrel daily, and the control group received only the vehicle. This treatment was continued for another 6 weeks postoperatively. At 6 weeks, the rabbits were euthanized and postmortem histologic and histomorphometric evaluation of the implants was performed. Results: The surgical procedures and postoperative period were uneventful and well tolerated by all animals without any surgical wound dehiscence, signs of infection, or other complication. No implant failure was observed in any of the groups. Histomorphometric analysis showed that bone-to-implant contact (BIC) was 48.77% for the clopidogrel group and 34.65% for the control group, with statistically significant difference between them (P < .001). Moreover, clopidogrel group had significantly greater bone tissue density (40.52% vs 28.74%, respectively; P <.001) and mean trabecular thickness (284.7 μm vs 180.7 μm, respectively; P < .001) in proximity to the implant surface than the control group, while the mean trabecular number had no difference between groups (1.56 vs 1.60, respectively; P = .961). Conclusions: The present study showed that continuous clopidogrel treatment does not negatively affect osseointegration, but rather promotes it in terms of BIC and bone density around the titanium implants. Further studies on the effect of the P2Y12 receptor and its antagonists on peri-implant bone homeostasis may provide useful information or applications for long-term success of dental implant therapy. [ABSTRACT FROM AUTHOR]

UNLABELLED: Hip fracture risk assessment is an important but challenging task. Quantitative CT-based patient-specific finite element (FE) analysis (FEA) incorporates bone geometry and bone density in the proximal femur. We developed a global FEA-computed fracture risk index to increase the prediction accuracy of hip fracture incidence. PURPOSE: Quantitative CT-based patient-specific finite element (FE) analysis (FEA) incorporates bone geometry and bone density in the proximal femur to compute the force (fracture load) and energy necessary to break the proximal femur in a particular loading condition. The fracture loads and energies-to-failure are individually associated with incident hip fracture, and provide different structural information about the proximal femur. METHODS: We used principal component analysis (PCA) to develop a global FEA-computed fracture risk index that incorporates the FEA-computed yield and ultimate failure loads and energies-to-failure in four loading conditions of 110 hip fracture subjects and 235 age- and sex-matched control subjects from the AGES-Reykjavik study. Using a logistic regression model, we compared the prediction performance for hip fracture based on the stratified resampling. RESULTS: We referred the first principal component (PC1) of the FE parameters as the global FEA-computed fracture risk index, which was the significant predictor of hip fracture (p-value

Objective Methods Results Conclusion To compare the efficacy of romosozumab (ROMO) and denosumab (DEN) in prevalent long‐term glucocorticoid (GC) users.Adult patients receiving oral prednisolone (≥5 mg/day) with high risk of fracture were randomized to receive subcutaneous ROMO (210 mg monthly) or DEN (60 mg 6‐monthly) for 12 months, followed by DEN for two more doses. The primary end point was the change in spine bone mineral density (BMD) from Months 0 to 12. Secondary end points included changes in BMD of the spine/hip/femoral neck and bone turnover markers at various time points and adverse events.Seventy patients (age 62.6 ± 9.1 years; 96% women; median prednisolone dose 5.0 mg/day; duration of therapy 10.7 ± 7.4 years) were enrolled, and 63 completed the study. At Month 12, the spine BMD increased significantly in both ROMO (+7.3% ± 4.5%; p < 0.001) and DEN (+2.3% ± 3.1%; p < 0.001) groups. The absolute spine BMD gain from Months 0 to 12 was significantly greater in ROMO‐treated patients (p < 0.001). Although the total hip BMD at Month 12 also increased significantly in the ROMO (+1.6% ± 3.3%; p = 0.01) and DEN groups (+1.6% ± 2.6%; p = 0.003), the absolute BMD gain was not significantly different between the groups. At Month 24, the spine BMD continued to increase in both the ROMO (+9.7% ± 4.8%; p < 0.001) and DEN group (+3.0% ± 3.0%; p < 0.001) compared to baseline, and the absolute BMD gain remained significantly greater in ROMO‐treated patients. The total hip BMD continued to increase in both groups (ROMO +2.9% ± 3.7%; p < 0.001; DEN +2.2% ± 3.4%; p = 0.001), but the changes from baseline were similar. Injection site reaction was more frequently reported in ROMO‐treated patients.ROMO was superior to DEN in raising the spine BMD at Month 12 in chronic GC users. After switching to DEN, ROMO‐treated patients continued to gain spine BMD to a greater extent than DEN until Month 24. [ABSTRACT FROM AUTHOR]

Background: The impact of extra-articular deformities (EADs) on lower limb alignment and collateral ligament integrity during total knee arthroplasty (TKA) poses significant challenges, increasing surgical complexity. Our study aims to evaluate the influence of EADs on mechanical axis alignment and the risk of collateral ligament injury during TKA using an AI-assisted surgical planning system, with the goal of minimizing ligament damage through precise and scientific planning. Methods: A healthy volunteer underwent CT and MRI scans of the lower limbs. The scan images were imported into Mimics 20.0 software, and the reconstructed models were spatially aligned using 3-maticResearch 11.0 software. Using Unigraphics NX9.0 software, 50 three-dimensional models of femoral lateral joint deformities with varying positions and angles were created. Finally, TKA was simulated using the AI JOINT preoperative planning system. Results: The larger the deformity angle and the closer it is to the knee joint, the more pronounced the deviation of the mechanical axis. During MA-aligned osteotomy, nine types of deformities can damage the collateral ligaments. After adjusting the varus/valgus of the prosthesis within a safe range of 3° and leaving a residual 3° varus/valgus in the lower limb alignment, only the 25° varus and 25° valgus deformities located at 90% of the femoral anatomical axis remain uncorrected. Conclusion: For patients with osteoarthritis and concurrent EAD undergoing TKA, using reconstructed 3D models of the collateral ligaments for preoperative planning helps visually assess collateral ligament damage, providing a practical solution. Minimizing intra-articular osteotomies within a safe range and allowing some residual alignment deviation can reduce the risk of collateral ligament injury. [ABSTRACT FROM AUTHOR]

Background: Orthopedic surgeons use manual measurements, acetate templating, and dedicated software to determine the appropriate implant size for total knee arthroplasty (TKA). This study aimed to use deep learning (DL) to assist in deciding the femoral and tibial implant sizes without manual manipulation and to evaluate the clinical validity of the DL decision by comparing it with conventional manual procedures. Methods: Two types of DL were used to detect the femoral and tibial regions using the You Only Look Once algorithm model and to determine the implant size from the detected regions using convolutional neural network. An experienced surgeon predicted the implant size for 234 patient cases using manual procedures, and the DL model also predicted the implant sizes for the same cases. Results: The exact accuracies of the surgeon's template were 61.54% and 68.38% for predicting femoral and tibial implant sizes, respectively. Meanwhile, the proposed DL model reported exact accuracies of 89.32% and 90.60% for femoral and tibial implant sizes, respectively. The accuracy ± 1 levels of the surgeon and proposed DL model were 97.44% and 97.86%, respectively, for the femoral implant size and 98.72% for both the surgeon and proposed DL model for the tibial implant size. Conclusion: The observed differences and higher agreement levels achieved by the proposed DL model demonstrate its potential as a valuable tool in preoperative decision-making for TKA. By providing accurate predictions of implant size, the proposed DL model has the potential to optimize implant selection, leading to improved surgical outcomes. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the effectiveness of combined core decompression (CD), bone grafting (BG), and platelet-rich plasma (PRP) in treating early-stage avascular necrosis of the femoral head (ANFH). Methods: A retrospective study was conducted on 74 patients (85 hips) with Ficat-Arlet stage I-II ANFH who were treated at our hospital between May 2015 and May 2018. The control group (20 patients, 22 hips) received symptomatic treatments, including weight-bearing reduction and oral analgesics. The CD + BG group (29 patients, 34 hips) underwent CD and β-tricalcium phosphate bone grafting. The PRP combination group (25 patients, 29 hips) received PRP injections in addition to CD and BG. Patients were followed up for five years to assess the necessity for total hip arthroplasty (THA). Data analysis was performed on those from the CD + BG and PRP groups who did not require THA. Clinical outcomes were evaluated using the Visual Analog Scale (VAS), Harris Hip Score (HHS), and the proportion of patients not accepting THA. Results: At the five-year follow-up, the rate of THA in the control group was 68.18% (15/22), while in the CD + BG group and the PRP combination group, the rates were 17.65% (6/34) and 10.34% (3/29), respectively. There was no statistically significant difference between the CD + BG group and the PRP combination group (P = 0.441), but both differed significantly from the control group (P < 0.001). Kaplan-Meier survival analysis showed that over time, the proportion of patients in the PRP combination group who did not require THA was consistently higher than that in the CD + BG group. Among patients who did not undergo THA, the proportion of Ficat-Arlet stage I-II patients in the PRP combination group was 88.46% (23/26), which was higher than the 64.29% (18/28) in the CD + BG group, showing a significant difference (P = 0.038). VAS score and HHS were compared between the two groups at 6 months, 12 months, and the last follow-up point, with patients in the PRP combination group showing better scores than those in the CD + BG group (p < 0.05) in both metrics. Conclusion: The combination therapy of CD, BG, and PRP demonstrates significant advantages in improving symptoms and delaying disease progression in early-stage ANFH. [ABSTRACT FROM AUTHOR]

Background: Medial soft tissue release is occasionally performed to achieve mediolateral ligament balance in total knee arthroplasty (TKA), whose sequential effect on mediolateral and anteroposterior stability remains unclear. This study aimed to quantitatively evaluate the difference in mediolateral and anteroposterior stability according to a sequential medial soft tissue release in TKA. Methods: Cruciate-retaining TKA was performed in six cadaveric knees. Medial and lateral joint gaps, varus-valgus angle, and tibial anterior and posterior translations relative to the femur with pulling and pushing forces, respectively, were measured. All measurements were performed at full extension and 45° and 90° flexion after release of the deep medial collateral ligament (MCL) (stage 1), the posteromedial capsule (stage 2), and the superficial MCL (stage 3). Mediolateral and anteroposterior stability were compared between stages, and correlations between mediolateral and anteroposterior stability were analyzed. Results: Medial joint gap significantly increased from stages 1 to 3 by 3.2 mm, 6.8 mm, and 7.2 mm at extension, 45° flexion, and 90° flexion, respectively, and from stages 2 to 3 by 3.5 mm at extension. Varus-valgus angle was varus at stage 2, which turned to valgus at stage 3 (−2.7° to 0.8°, −2.2° to 4.3°, and −5.5° to 2.5° at extension, 45° flexion, and 90° flexion, respectively). Anterior translation at 90° flexion significantly increased from stages 1 and 2 to stage 3 by 11.5 mm and 8.2 mm, respectively, which was significantly correlated with medial gap (r = 0.681) and varus-valgus angle (r = 0.495). Conclusions: Medial soft tissue release also increased tibial anterior translation as well as medial joint gap, and medial joint gap and tibial anterior translation were significantly correlated. Surgeons should be careful not to create too large medial joint gap and tibial anterior translation in flexion by excessive medial release up to the superficial MCL for achieving an equal mediolateral joint gap in extension. [ABSTRACT FROM AUTHOR]

Background: Controversy exists regarding the origin of femoral torsion, and specific treatment rules regarding the optimal position of femoral osteotomy in patients with recurrent patellar subluxation and excessive femoral torsion are scarce. Purpose: To establish a novel classification system for such patients, and to compare clinical and radiological outcomes after distal derotational femoral osteotomy (DDFO) between femoral torsion at proximal (neck and shaft) and distal levels. Methods: Between January 2014 and June 2019, patients who underwent DDFO were retrospectively reviewed. The segmental torsion analysis was performed to establish a novel classification system, and classify included patients into two groups: 35 patients in proximal torsion group and 38 patients in distal torsion group. These patients were followed-up for at least 3 years. Clinical evaluations included functional outcomes, physical examinations, quality of life, activity level, satisfaction, and complications. Radiological outcomes included patellofemoral osteoarthritis, congruence, and alignment. Results: Type I was defined as the proximal torsion. Type II was defined as the distal torsion. Proximal torsion group had lower postoperative femoral torsion (12.6 ± 2.6° vs. 14.8 ± 3.6°; P =.004) and higher surgical correction angle (21.6 ± 5.0° vs. 19.1 ± 3.0°; P =.009). All clinical and radiological outcomes improved significantly in both groups, but proximal torsion group had significantly higher quality of life (EQ-5D-5L: 0.96 ± 0.06 vs. 0.91 ± 0.07; P =.003. EQ-VAS: 92.0 ± 6.0 vs. 88.7 ± 5.8; P =.021) and Tegner activity score (5.2 ± 1.5 vs. 4.5 ± 1.4; P =.040), and fewer patellofemoral osteoarthritis (8.6% vs. 26.3%; P =.048). Two patients in the distal torsion group had subjective patellar instability. The percentage of patients with anterior knee pain was higher in the distal torsion group. Conclusion: A novel classification system for patients with recurrent patellar subluxation and excessive femoral torsion based on segmental femoral torsion analysis was established. DDFO was more appropriate for patients with proximal torsion, yielding higher surgical correction angle, and better clinical and radiological outcomes. Study design: Cohort study; Level of evidence, 3. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Level of evidence Unicondylar arthroplasty was performed using robotic medial unicompartmental knee arthroplasty (R‐mUKA) and gap‐balancing instrumentation. Our hypothesis was that robotic unicondylar knee arthroplasty accurately restores component positioning and lower limb alignment when compared to preoperative planning with actual implantation throughout the range of knee motion due to proper knee balancing.Data were collected prospectively and were analysed for patients undergoing RM‐UKA. A cemented UKA was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded of the native knee, with the trial components in place and finally after component implantation. A spacer according to the femorotibial gap was introduced and the alignment was measured. The position of the final component was planned based on three‐dimensional computed tomography images before making the bone cuts. The positioning of the femoral and tibial components was analysed in all three planes.A total of 52 patients were included (mean age 66.3 ± 6.7 years; 34 males, 18 females). The difference in femoral component position after planning and final implantation was 0.04° ± 0.58° more valgus in the coronal plane (p = 0.326) and 0.6° ± 1.4° more flexion relative to the sagittal plane (p = 0.034). The tibial component was placed in the coronal plane in 0.3° ± 0.8° of more varus (p = 0.113) and in the sagittal plane in 0.6° ± 1.2° of more posterior tibial slope (p = 0.001). Lower limb alignment of the native knee in extension was 5.8° ± 2.6° of varus and changed to 3° ± 2.1° varus after UKA (p ≤ 0.01).R‐mUKA helps to achieve the target of alignment and component position without any significant differences to the planning. Ligament balancing causes non‐significant changes in component position. It allows optimal component position even for off‐the‐shelf implants respecting the patient's specific anatomy.II [ABSTRACT FROM AUTHOR]

Introduction: Surgical treatment of distal femoral fractures (DFFs) in osteoporotic bone is challenging despite improvements in hardware and surgical techniques. The occurrence and degree of secondary displacement during healing after bridging plate fixation are still unknown. This study aimed to assess the occurrence and degree of secondary displacement in healing DFFs in elderly patients and correlate the secondary displacement to body mass index, bone density, and weight-bearing regimen. Patients and Methods: The study involved 32 patients, 65 years or older, with a DFF of AO/OTA types 33 A2-3, B1-2, C1-2, and 32(c) A-C,1-3, including peri-prosthetic fractures with stable implants. Twenty-seven patients had at least 8 weeks of follow-up, and 21 patients had a complete 1-year follow-up. Minimally invasive surgery was performed using a distal anatomical femoral plate as a long bridge-plating construct. Secondary displacement was assessed with computed tomography of the entire femur postoperatively and at 8, 16, and 52 weeks. Femoral length, coronal angulation (varus/valgus), and subsidence as the change in distance between the distal joint surface and a specified locking screw were measured. Results: There was a statistically significant mean femoral shortening at 52 weeks of 4.7 mm (SD 3.9, (95% CI 2.9–6.5), P < 0.001) mainly by subsidence of the distal fragment. Most patients experienced limited coronal angulation. There was no correlation between body mass index or bone density and secondary displacement. At the 1-year follow-up, no patient needed revision surgery for non-union or plate breakage. Restricted weight-bearing for 8 weeks did not prevent secondary displacements or adverse events such as cut-outs. Conclusion: Modern dynamic plate osteosynthesis could not prevent commonly occurring fracture subsidence in DFF in an elderly cohort. Restricted weight-bearing for 8 weeks did not prevent secondary displacements or mechanical adverse events. [ABSTRACT FROM AUTHOR]

Metabolic bone diseases (MBDs) are a diverse group of diseases, affecting the mass or structure of bones and leading to reduced bone quality. Parameters representing different aspects of bone health can be obtained from various magnetic resonance imaging (MRI) methods such as proton MR spectroscopy, as well as chemical shift encoding-based water-fat imaging, that have been frequently applied to study bone marrow in particular. Furthermore, T2* mapping and high-resolution trabecular bone imaging have been implemented to study bone microstructure. In addition, quantitative susceptibility mapping and ultrashort echo time imaging are used for trabecular and cortical bone assessment. This review offers an overview of technical aspects, as well as major clinical applications and derived main findings, for MRI-based assessment of bone quality in MBDs. It focuses on osteoporosis as the most common MBD. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to answer the following questions. What was functional results of pediatric patients receiving a short stem allograft-prosthesis composite of the proximal femur? What was complication rate and revision-free implant survival? Was it possible to preserve the bone stock of the proximal femur in pediatric patients? Methods: We reviewed 10 pediatric patients treated with proximal femur resection for a primary bone tumor and reconstruction with short stem allograft-prosthesis composite, with at least 24 months follow-up. The median age was 9 years (4–13) at surgery. The mean resection length was 15 cm (6–29). In six cases, fixation was performed with a short plate positioned under the great trochanter while in four cases a long plate extended over the great trochanter was employed. Results: Nine complications that required surgical revision were assessed in six patients (one wound dehiscence, two nonunions, two fractures, one acetabular wear, three hypometria), while allograft-prosthesis composite removal was required in three patients. The revision-free survival was 57% (95% confidence interval 33%–100%) at 5 and 10 years. The graft removal-free survival was 75% (95% confidence interval 50%–100%) at 5 and 10 years. The mean Musculo-Skeletal Tumor Society Score was 28 (20–30). Conclusions: Allograft-prosthesis composites with short stem and compression plate represents an effective reconstructive option after proximal femur resection for primary bone tumors in growing patients, preserving bone stock. The use of a compression plate extended over the greater trochanter seemed to reduce failure rate. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the chicken femur as a laboratory model for the human metacarpal by comparing the bone microarchitecture and mechanical properties of chicken femurs to human cadaveric metacarpals. Methods: Sixteen fresh chicken femora and 20 fresh frozen cadaveric human metacarpals were imaged using a micro computed tomography scanner. The bones were then mechanically tested using four-point-bending and torsional testing. Results: There were no significant differences in macroscopic features between chicken femora and human metacarpals, including overall length, external radius, internal radius, cortical width and cross-sectional area of the diaphyseal cortex (p > 0.05). There were no significant differences in the trabecular number and spacing in the distal metaphysis of both groups (p > 0.05). The diaphysis and proximal metaphysis did not share any microarchitectural similarities. Four-point bending tests resulted in significantly higher yield forces, ultimate force, failure points and stiffness in human metacarpals (p < 0.05). Torsion tests resulted in significant higher ultimate torque and torsional rigidity in human metacarpals (p < 0.05). Conclusions: The chicken femur has structural and biomechanical differences to the fresh frozen human metacarpal despite the similarity in their macroscopic features. [ABSTRACT FROM AUTHOR]

This paper presents a surgical technique for the removal of an old universal femoral nail preceding total hip arthroplasty (THA) in a 50‐year‐old male patient with left hip osteoarthritis. The patient had undergone femur nail insertion approximately 35 years ago. Due to the necessity of nail removal prior to THA, surgery to remove the nail was planned. There are challenges posed by the design of the old universal femoral nail system, particularly its side slot which made engagement of the conical bolt difficult. The successful removal of the nail was eventually achieved, enabling subsequent THA. Individuals who received this old implant years ago may now require its removal as part of osteoarthritis treatment. Given the lack of familiarity among surgeons with this outdated implant, this paper is aimed at providing essential guidance and insights regarding its removal procedure. This literature represents the inaugural documentation of the surgical technique for the removal of an aged femur nail. [ABSTRACT FROM AUTHOR]

Improper osteotomy during total knee arthroplasty (TKA) can lead to anterior femoral notching, which increases the risk of periprosthetic fractures due to stress concentration. One potential solution is the addition of an intramedullary stem to the femoral component. However, the optimal stem length remains unclear. In this study, we aimed to determine the optimal stem length using finite element models. Finite element models of femurs were developed with unstemmed prostheses and prostheses with stem lengths of 50, 75, and 100 mm. Under squat loading conditions, the von Mises stress at the notch and stress distribution on four transversal sections of the femur were analyzed. Additionally, micromotion of the prosthesis–bone interface was evaluated to assess initial stability. The unstemmed prosthesis exhibited a von Mises stress of 191.8 MPa at the notch, which decreased to 43.1, 8.8, and 23.5 MPa for stem lengths of 50, 75, and 100 mm, respectively. The stress reduction on four selected femoral transversal sections compared with the unstemmed prosthesis was 40.0%, 84.4%, and 67.1% for stem lengths of 50, 75, and 100 mm, respectively. Micromotion analysis showed a maximum of 118.8 μm for the unstemmed prosthesis, which decreased significantly with the application of stems, particularly at the anterior flange. Intramedullary stems effectively reduced stress concentration at the femoral notch. The 50‐mm stem length provided the optimal combination of reduced notch stress, minimized stress‐shielding effect, and decreased micromotion at the anterior flange. [ABSTRACT FROM AUTHOR]

Background: Postoperative periprosthetic femoral fracture (POPFF) after total hip replacement (THR) requires complex surgery and is associated with a high morbidity, mortality, and cost. Although the United Kingdom based National Joint Registry (NJR) captures over 95% of THRs treated with revision, before June 2023 it did not capture POPFF treated with fixation. We aimed to estimate the incidence and epidemiology of POPFF treated with either surgery in England. Methods and findings: We performed a retrospective analysis of a mandatory, prospective database (NJR) linked to Hospital Episode Statistics (HES). All linkable primary THRs between 01/01/2004 and 31/12/2020 were included. Revision or fixation of POPFF were identified using a combination of procedural and diagnosis codes. We identified 809,832 THRs representing 5,542,332 prosthesis years at risk. A total of 5,100 POPFF were identified that had been surgically treated by revision, fixation, or both, and 2,831 of these fractures were treated with fixation alone, meaning 56% were not represented with revision data alone. The incidence of POPFF needing surgery was 0.92 (95% CI 0.90, 0.95) per 1,000 prostheses years. This incidence was higher in patients over the age of 70 at the time of primary THR (1.31 [95% CI 1.26, 1.35] per 1,000 prostheses years) and for patients who underwent THR for hip fracture (2.19 [95% CI 1.97, 2.42] per 1,000 prostheses years). This incidence appears to be increasing year on year. The cumulative probability of sustaining a POPFF within 10 years of THR was 1% and over 15% of patients died within 1 year of surgery for a POPFF. Conclusions: To date, the incidence of POPFF may have been underestimated with over 50% of cases missed if the case identification in this study is correct. After including these cases, we observed that POPFF is the largest reason for major reoperation following THR and patients sustaining these injuries have a high risk of death. The prevention and treatment of POPFF and requires further resource allocation and research. Jonathan Nicholas Lamb and colleagues perform a retrospective analysis of UK data sources to investigate the true incidence of periprosthetic femoral fracture following total hip replacement. Author summary: Why was the study done?: When the thigh bone supporting a hip replacement breaks because of injury, it is called a periprosthetic fracture of the femur. Patients are usually treated with major surgery, which is associated with significant risk of complications, high cost, and even death. Currently the best estimates of how often these injuries occur after hip replacement in England are made using data which only counts when fractures are treated with one surgical method, revision and therefore miss a large proportion of cases. This study is the first large study combining hospital data and the best currently used source to get a much more complete picture of when these fractures occur. In addition to revision, the study was able to capture the other common treatment method, i.e., fixation, thereby providing a comprehensive and more meaningful review. What did the researchers do and find?: A very large data set of all hip replacements performed in England were matched to health data on hospital admissions to find patients who were treated with either exchange of implants (revision) and fixation of the fracture without exchange of implants. This study found that previous estimates of periprosthetic fractures only represented about half of the actual number treated in hospitals over the past 2 decades. When cases treated with revision and fixation are combined, periprosthetic fracture appears to be the most common cause of major re-operation after hip replacement. Patients who go on to sustain a fracture tended to be older and frailer at the time of the first hip replacement than those who do not go on to break. One in 25 patients with fractures died within 30 days of their operation, and the hospital length of stay was over 2 weeks. What do these findings mean?: These results suggest that periprosthetic fracture after hip replacement is the biggest problem facing patients with a hip replacement and the scale of the problem has previously been underestimated. Health care providers and researchers should prioritise the prevention and care for these vulnerable patients. [ABSTRACT FROM AUTHOR]

Purpose: To examine the frequency of patellofemoral joint (PFJ) osteoarthritis (OA) and its symptoms in the long-term course of open-wedge high tibial osteotomy (OWHTO). Methods: We analyzed 113 joints of 91 patients. OA and osteonecrosis (ON) developed in 91 and 22 joints, after an average postoperative period of 127.5 ± 19.5 months. For X-ray evaluation, the standing femorotibial angle (FTA), % mechanical axis (%MA), Caton–Deschamps index (CDI), patellar tilt angle (TA), lateral patellar shift (LPS), and PFJ space width (medial [MJS] and lateral [LJS]) were analyzed. PFJ-associated symptoms were evaluated using the hospital for special surgery patellar score (HSS-PS) and knee injury and osteoarthritis outcome score patellofemoral subscale (KOOS-PF). Statistical analysis was performed with paired and unpaired t tests, and a risk rate of less than 1% was significantly judged. Results: Preoperative FTA and CDI decreased from 180.8° to 170.0° and 0.88 to 0.70 at the final follow-up. Preoperative %MA lateralized from 20.8 to 66.0 at the final follow-up. TA and LPS values decreased significantly compared with before surgery until plate removal. The MJS and LJS significantly decreased, and OA with a joint space < 3 mm occurred in 14 cases. However, HSS-PS and KOOS-PF scores were not significantly different between the groups with and without OA. Conclusion: PFJ OA occurred in 12.4% cases in the long-term postoperative course of OWHTO; however, no symptomatic difference was found in the group with or without OA. [ABSTRACT FROM AUTHOR]

Background: Computed tomography (CT) based three-dimensional templating is increasingly being used to predict implant sizes in total knee arthroplasty (TKA). However, the existing data is heterogeneous, and the majority of studies lack adequate statistical power. This study investigated whether preoperative CT-based planning in robot-assisted TKA (RA-TKA) helps in predicting the accurate size of implant used. Methods: This is a single-center retrospective study of 632 consecutive RA-TKA surgeries. All surgeries were performed using a fully automatic Cuvis RA-TKA system. Cohen's Kappa (κ) coefficient was used to measure the level of agreement between the predicted and the final implant sizes. Results: A total of 632 knees were operated on 384 patients. A total of 136 unilateral cases whereas 248 patients had both knees operated on. For the tibial component, in 21.7% cases a bigger implant size was used while in 11.8% cases a smaller size was used. For the femoral component, in 5.1% cases a bigger implant size was used while in 4.9% cases a smaller size was used. The agreement between the predicted and actual implant sizes was moderate for the tibial component [κ = 0.56 (95% CI: 0.51 to 0.61); p < 0.001] and almost perfect for the femoral component [κ = 0.87 (95% CI: 0.84 to 0.90); p < 0.001]. Conclusion: This study suggests that planning of RA-TKA using a CT-based model can be valuable to surgeons in accurately predicting the component size for femur and to a lesser degree for tibia. Future studies should investigate the potential predictors of discordance between the predicted and actual tibial implant sizes. [ABSTRACT FROM AUTHOR]

Introduction: Hydatid disease is uncommon in Humans. It rarely affects the bones and joints (0.5–4%). Frequent sites of bony involvement are vertebrae, pelvic bones, upper end of long bones e.g. humerus, femur and tibia. Material and methods: We report a case of 41-year old female with primary Hydatid cyst of the entire right femur. Patient complaint of severe pain and was non ambulatory since the last 2 months. Results: Here, single staged Total Right Femur Replacement was done under General Anaesthesia. Patient was discharged after 6 days of hospital stay in a stable condition where physical rehabilitation was initiated after day one of the surgery, progressing to aided walking, standing and active lower limb exercises. Conclusion: Involvement of the entire femur was a challenging case. There is no consensus/gold standard treatment of severe cases. Given the involvement of the entire Right Femur along with spillage in the neighbouring muscles, patient underwent Total Femur Replacement with Hip and Knee Replacement. [ABSTRACT FROM AUTHOR]

Bone formation is tightly modulated by genetically encoded molecular proteins that interact to regulate cellular differentiation and secretion of bony matrix. Many transcription factors are known to coordinate these events by controlling gene transcription within networks. However, not all factors involved are known. Here, we identified a novel function for Zinc Finger Homeobox 3 (Zfhx3), a gene encoding a transcription factor, as a regulator of bone metabolism. We knocked out Zfhx3 conditionally in mice in either chondrocytes or osteoblasts and characterized their bones by micro-CT in 12-week-old mice. We observed a negative effect in linear bone growth in both knockout mice but reduced bone mass only in mice with Zfhx3 deleted in osteoblasts. Loss of Zfhx3 expression in osteoblasts affected trabecular bone mass in femurs and vertebrae in both sexes but influenced cortical bone volume fraction only in females. Moreover, transcriptional analysis of femoral bones in osteoblast Zfhx3 conditional knockout mice revealed a reduced expression of osteoblast genes, and histological evaluation of trabecular bones suggests that Zfhx3 causes changes in bone formation and not resorption. The loss of Zfhx3 causes reductions in trabecular bone area and osteoid volume, but no changes in the expression of osteoclast differentiation markers or number of TRAP stained osteoclasts. These studies introduce Zfhx3 as a relevant factor toward understanding gene regulatory networks that control bone formation and development of peak bone mass. [ABSTRACT FROM AUTHOR]

We investigated the effects of exercise training on bone mineral density (BMD) in people living with Human Immunodeficiency Virus (PLHIV). Pubmed, Scopus, Cochrane Library, and ScienceDirect databases were searched for trials investigating exercise training-induced changes in BMD of PLHIV at baseline vs. post-intervention assessed by dual-energy X-ray absorptiometry (DXA). Hedge effect sizes (ES) were calculated incorporating fixed effects for BMD variation assumptions. Disaggregated comparisons were performed for trials with more than one intervention or BMD site assessment. Seven trials included 210 PLHIV and 35 non-HIV-infected controls. Methodological quality evaluated using the Physiotherapy Evidence Database (PEDro) scale ranged from poor to moderate. Interventions applied isolated resistance, combined aerobic and resistance, and multimodal exercise protocols performed 3 d/wk for 12-to 104 week. One controlled and another uncontrolled trial presented significant effects, reporting improvements at the femoral neck and total (ES 2.14 and 0.49, respectively). Magnitude of those specific ES influenced the overall effect (controlled and uncontrolled trials), which was small but significant (k = 12, ES 0.277, 95% confidence interval 0.120-0.434). Resistance training may promote favorable adaptations in BMD of PLHIV, particularly in femur. Future research should elucidate the optimal dose-response relationship and physiological mechanisms underlying exercise-induced adaptations on the BMD of PLHIV. [ABSTRACT FROM AUTHOR]

Intramedullary nails (ILNs) are commonly used in orthopedic surgery for the fixation of long bone fractures and limb lengthening. Understanding the structural mechanics (i.e. nail bend) of an ILN device is crucial in determining its performance under various loading conditions. Furthermore, nail diameter was found to play a key role in an ILN's susceptibility to plastic deformity. This study aims to investigate the degree of nail bending and incidence of plastic deformity in patients receiving antegrade femoral ILNs (PRECICE, NuVasive, Inc.). Retrospectively evaluated 130 ILNs (PRECICE, NuVasive, Inc.) in 100 adult patients who underwent limb lengthening done in a single center. Patients who had concomitant osteotomies, tibial lengthening, malunion, non-union, mechanical failure, or revision surgery for any reason were excluded. All nails were inserted through the greater trochanter or piriformis. Patients' age, weight, height, and body mass index (BMI)were extracted. Radiologic assessments involved analyzing long lower limb standing X-rays before, during, and at consolidation for total distraction and nail bend. Naildiameter and patient characteristics were directly sourced from medical records. Nail bend at consolidation averaged 2.4° (SD 2.4), ranging from 0 to 9. Additionally, total femoral lengthening was assessed, with a mean value of 5.3 cm (SD 2.1). A significant positive association was observed in the nail bend and weight (weight in kg/nail diameter in mm) coefficient (P < 00.01). Bilateral limb lengthening was also correlated to increase nail bend (P < 00.05). Patient's weight to nail diameter ratio and bilateral limb lengthening were found to be significant factors affecting nail bend. These findings advance our understanding of the interrelation between the nail biomechanical profile and the patient's physical attributes, offering important implications for limb lengthening. III. [ABSTRACT FROM AUTHOR]

Subchondral defects are often caused by trauma involving cartilage damage, leading to subsequent damage to the underlying bone, specifically the subchondral region. Bilayer scaffolds made from biomaterials, such as bovine hydroxyapatite, possess biocompatible and biodegradable properties that mimic the natural environmental conditions of target tissues so that they can support the formation of new tissues. On the other side, diclofenac as an anti‐inflammatory drug potentiates to inhibit the inflammatory excess regarding the damage. This study aims to study the effectiveness of diclofenac scaffold to rabbit joint defect model. The scaffold was implanted in the rabbit femoral trochlear bone hole, which had a diameter of 5 mm and a depth of 4 mm. After 28 days of intervention, the animals were examined using macroscopic evaluation, hematoxylin‐eosin (HE) staining, and immunohistochemistry (IHC) for type I collagen and type II collagen. Subsequently, the cartilage was evaluated using the International Cartilage Repair Society (ICRS) scoring system. The macroscopic ICRS scores were significantly higher (p < 0.05) in the bilayer scaffold implantation group compared to the monolayer scaffold and control groups. Histological ICRS scores were also significantly higher (p < 0.05) in the bilayer scaffold group compared to the control group. Type II collagen expression was higher (p < 0.05) in the bilayer scaffold group compared to the monolayer scaffold and control groups, although type I collagen expression was lower in comparison. In conclusion, this research suggests that the diclofenac‐loaded bilayer scaffold effectively enhances cartilage and subchondral bone regeneration. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusions Level of Evidence This study aims to quantitatively assess the predictability of post‐resection gap dimensions and the attainment of balanced gaps using robotic arm‐assisted total knee arthroplasty (TKA).This retrospective cohort study included 100 consecutive patients who underwent robotic arm‐assisted TKA for knee osteoarthritis using a restricted functional alignment (FA) technique. Tibial cuts were performed based on preoperative tibial anatomy within predefined boundaries, followed by femoral component adjustments according to tensioned soft tissues to optimise gap balance. The primary outcome was the proportion of balanced gaps, defined as differential laxities of ≤2 mm, across extension, flexion, lateral, and medial gap measurements. Ligament balancing in lateral and medial compartments was assessed using a robotic system at 10° and 90° flexion to evaluate if restricted FA facilitated a balanced knee. Secondary outcomes included implant alignment, resection depth, and patient‐reported outcome measures (PROMs).Significant increases in both lateral and medial gaps at 10° and 90° flexion were observed following tibial and femoral bone resections (p < 0.001). At extension, average gap changes were 0.9 mm (lateral) and 1.6 mm (medial) after tibial cuts, and 0.5 mm (lateral) and 1.2 mm (medial) after femoral cuts. At 90° flexion, changes were 0.3 mm (lateral) and 1.7 mm (medial) following tibial cuts, and 1.0 mm (lateral) and 1.4 mm (medial) after femoral cuts. Despite these variations, the tibia‐first, gap‐balancing technique achieved overall balance in 98% of gap measurements. The tibial component was placed at an average of 2.1° varus, while the femoral component was positioned at 0.3° varus and 1.3° external rotation relative to the surgical transepicondylar axis. Significant improvements in PROMs were noted between preoperative and one‐year postoperative evaluations (all p < 0.05).The tibia‐first, restricted FA technique achieved a well‐balanced knee in 98% of cases, despite inconsistent gap increments observed between initial assessments and post‐resection.Therapeutic Level IV. [ABSTRACT FROM AUTHOR]

Objective: Observational studies have found associations between reproductive factors and bone density in women. However, the causal relationships are not well understood. This study aims to investigate whether various reproductive factors are causally related to bone density at different skeletal sites using both univariable and multivariable Mendelian randomization (MR) methods. Methods: The study incorporated four reproductive factors, namely, age at menarche (AAM), age at first live birth (AFB), age at menopause (ANM), and age at last live birth (ALB), as well as five distinct skeletal sites, including bone mineral density (BMD), heel calcaneus BMD, ultradistal forearm bone mineral density (FA-BMD), lumbar spine bone mineral density (LS-BMD), and femoral neck bone mineral density (FN-BMD). Univariable two-sample MR and multivariable MR analyses were conducted using data from published genome-wide association studies (GWASs). A total of 150 single nucleotide polymorphisms (SNPs) associated with the four reproductive factors were extracted from GWAS databases. The primary statistical analysis method utilized in this study was the inverse variance weighted (IVW) method. Results: In the univariate MR analysis, we observed causal connections between four reproductive factors and bone density. Specifically, AAM had a significant impact on BMD and heel calcaneus BMD. Age at first live birth was negatively associated with FA-BMD. Age at last live birth showed a negative correlation with BMD and heel calcaneus BMD. ANM exhibited positive associations with BMD, heel calcaneus BMD, FA-BMD, and LS-BMD. Subsequently, we performed a multivariable MR analysis to examine the combined effects of multiple variables, which confirmed the persistence of associations between age at menopause and bone density at various sites. Additionally, we found a negative correlation between age at last live birth and heel calcaneus BMD. Conclusion: This study offers a fresh perspective on the prevention of osteoporosis in women, explicitly stating that reproductive factors such as early menopause and late childbirth play a significant predictive role in individual bone density decline. Therefore, when developing osteoporosis screening and management protocols, reproductive factors should be included for a more comprehensive guidance of clinical practice. [ABSTRACT FROM AUTHOR]

Background: Bisphosphonates (BPs) are widely used to inhibit excessive osteoclast activity. However, the potential to compromise bone defect healing has limited their broader application. To better understand the influence of BPs on bone regeneration, we established a bone grafting model with Zoledronate administration, aiming to deepen the understanding of bone remodeling and mineralization processes. Methods: A bone grafting model was established in the distal femurs of male Sprague–Dawley rats. The experimental group received systemic administration of Zoledronate (ZOL, 0.2 mg/kg, administered twice). Histological analysis and immunohistochemistry (IHC) were employed to assess osteoblastic and macrophage activity, tartrate-resistant acid phosphatase (TRAP) staining was used to evaluate osteoclastogenesis. Mineralization was assessed through Micro-CT analysis, Raman spectroscopy, and back-scatter scanning electron microscopy (BSE-SEM). Additionally, the in vitro effects of ZOL on osteoblast and osteoclast activity were investigated to further elucidate its impact on bone regeneration. Results: In vivo, the ZOL group showed increased bone mass, as observed in histological and radiological assessments. However, Micro-CT, Raman spectroscopy, and BSE-SEM detection revealed lower mineralization levels in ZOL group's regenerated bone. Acid-etched SEM analysis showed abnormal osteocyte characteristics in ZOL-group's regenerated bone. Simultaneously, elevated osteopontin (OPN), F4/80 expression along with reduced TRAP expressing was found in the grafting region of ZOL group. In vitro, ZOL did not negatively impact osteogenetic activity (ALP, BMP4, OCN expression) at the tested concentrations (0.02–0.5 g/ml) but significantly impaired mineralization and inhibited osteoclast formation, even at the lowest concentration. Conclusions: This study highlights a less recognized negative effect of ZOL on bone mineralization during bone regeneration. More research is needed to elucidate the underlying mechanism. [ABSTRACT FROM AUTHOR]

Among the most widely used methods for understanding human-horse relationships in the archaeological record is the identification of human skeletal pathologies associated with mounted horseback riding. In particular, archaeologists encountering specific bony changes to the hip, femur, and lower back often assert a causal link between these features and prolonged periods of mounted horseback riding. The identification of these features have recently been used to assert the early practice of mounted horseback riding among the Yamnaya culture of western Eurasia during the third and fourth millennium BCE. Here, we summarize the methodological hurdles and analytical risks of using this approach in the absence of valid comparative datasets and outline best practices for using human osteological data in the study of ancient animal transport. [ABSTRACT FROM AUTHOR]

BACKGROUND: Establishing an objective and standard animal model of bone nonunion is essential for experimental studies and treatment of nonunion. OBJECTIVE: To establish an objective animal model for experimental studies of nonunion. METHODS: Specific pathogen-free male Wistar rats were selected and prepared by cutting off a 5 mm bone defect in the middle femur, peeling off a large periosteum and removing bone marrow. Animal models were fixed with a 1.2 mm Kirschner wire. At 1, 4 and 8 weeks, bone nonunion was observed by gross specimen observation, X-ray examination and histopathological examination. RESULTS AND CONCLUSION: The gross specimen, X-ray film and histopathological examination showed that there was no callus formation in the bone defect area, the broken end was filled with fiber tissue, and the bone callus was rare or even invisible. To conclude, the rat model of nonunion can be successfully established by osteotomy of the middle femur, large periosteum peeling and bone marrow removal. This modeling method is simple, reliable and effective. [ABSTRACT FROM AUTHOR]

Objective: Fibroblast growth factor 21 (FGF21) is a secreted protein that regulates body metabolism. In recent years, many observational studies have found that FGF21 is closely related to bone mineral density and osteoporosis, but the causal relationship between them is still unclear. Therefore, this study used two-sample, mediated Mendelian randomization (MR) analysis to explore the causal relationship between FGF21 and osteoporosis and bone mineral density. Methods: We conducted a two-sample, mediator MR Analysis using genetic data from publicly available genome-wide association studies (GWAS) that included genetic variants in the inflammatory cytokine FGF21, and Total body bone mineral density, Heel bone mineral density, Forearm bone mineral density, Femoral neck bone mineral density, osteoporosis. The main analysis method used was inverse variance weighting (IVW) to investigate the causal relationship between exposure and outcome. In addition, weighted median, simple median method, weighted median method and MR-Egger regression were used to supplement the explanation, and sensitivity analysis was performed to evaluate the reliability of the results. Results: MR Results showed that FGF21 overexpression reduced bone mineral density: Total body bone mineral density (OR=0.920, 95%CI: 0.876-0.966), P=0.001), Heel bone mineral density (OR=0.971, 95%CI (0.949-0.993); P=0.01), Forearm bone mineral density (OR=0.882, 95%CI(0.799-0.973); P=0.012), Femoral neck bone mineral density (OR=0.952, 95%CI(0.908-0.998), P=0.039); In addition, it also increased the risk of osteoporosis (OR=1.003, 95%CI (1.001-1.005), P=0.004). Sensitivity analysis supported the reliability of these results. The effect of FGF21 overexpression on osteoporosis may be mediated by type 2 diabetes mellitus and basal metabolic rate, with mediating effects of 14.96% and 12.21%, respectively. Conclusions: Our study suggests that the overexpression of FGF21 may lead to a decrease in bone mineral density and increase the risk of osteoporosis, and the effect of FGF21 on osteoporosis may be mediated through type 2 diabetes and basal metabolic rate. This study can provide a reference for analyzing the potential mechanism of osteoporosis and is of great significance for the prevention and treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

Background: Optimal sagittal alignment of the femoral prosthesis is critical to the success of total knee arthroplasty (TKA). While robotic-assisted TKA can improve alignment accuracy, the efficacy of default femoral alignment versus individualized alignment remains under scrutiny. This study aimed to compare the differences in prosthetic alignment, anatomical restoration, and clinical outcomes between individualized femoral sagittal alignment and default sagittal alignment in robotic-assisted TKA. Methods: In a prospective randomised controlled trial, 113 patients (120 knees) underwent robotic-assisted TKA were divided into two groups: 61 with individualized femoral flexion (individualized alignment group) and 59 with default 3–5° flexion (default alignment group). The individualized alignment was based on the distal femoral sagittal anteverted angle (DFSAA), defined as the angle between the mechanical and distal anatomical axes of the femur. The radiographic and clinical outcomes were compared. Results: Despite similar postoperative femoral flexion angles between groups (P = 0.748), the individualized alignment group exhibited significantly lower incidences of femoral prosthesis extension and higher rates of optimal 0–3° prosthesis flexion (9.8% vs. 27.1%, P = 0.014,78.7% vs. 55.9%, p = 0.008, respectively). The individualized alignment group also demonstrated more favourable changes in sagittal anatomy, with higher maintenance of postoperative anterior femoral offset within 1 mm (54.1% vs. 33.9%, P = 0.026) and posterior condylar offset within 1 mm and 2 mm (44.3% vs. 25.4%, p = 0.031,73.8% vs. 50.8%, p = 0.010, respectively). Although slight improvement in the Hospital for Special Surgery Knee Score (HSS) at three months was observed (P = 0.045), it did not reach a minimal clinically important difference. Conclusion: Individualized tailoring of femoral sagittal alignment in robotic-assisted total knee arthroplasty (TKA) enhances prosthetic alignment and anatomical restoration, suggesting potential improvements in postoperative outcomes. [ABSTRACT FROM AUTHOR]

Background: The proximal femur is a common site of bone metastasis. The Mirels' score is a frequently utilized system to identify patients at risk for pathologic fracture and while it has consistently demonstrated strong sensitivity, specificity has been relatively poor. Our group previously developed a Modified Mirels' scoring system which demonstrated improved ability to predict cases at risk of fracture in this patient population through modification of the Mirels' location score. The purpose of the present study is to internally validate this newly developed scoring system on an independent patient series. Methods: Retrospective review was performed to identify patients who were evaluated for proximal femoral bone lesions. Patients were stratified into one of two groups: 1) those who went on to fracture within 4 months after initial evaluation (Fracture Group) and 2) those who did not fracture within 4 months of initial evaluation (No Fracture Group). Retrospective chart review was performed to assign an Original Mirels' (OM) Score and Modified Mirels' (MM) score to each patient at the time of initial evaluation. Descriptive statistics, logistic regression, receiver operating curve, and net benefit analyses were performed to determine the predictability of fractures when utilizing both scoring systems. Results: The use of the MM scoring improved fracture prediction over OM scoring for patients observed over a 4 month follow up based on logistic regression. Decision curve analysis showed that there was a net benefit using the MM score over the OM scoring for a full range of fracture threshold probabilities. Fracture prevalence was similar for current internal validation dataset when compared to the dataset of our index study with a comparable reduction in misclassification of fracture prediction when utilizing the modified scoring system versus the original. Conclusions: Use of MM scoring was found to improve fracture prediction over OM scoring when tested on an internal validation set of patients with disseminated metastatic lesions to the proximal femur. The improvement in fracture prediction demonstrated in the present study mirrored the results of our index study during which the MM system was developed. [ABSTRACT FROM AUTHOR]

Repairing or reconstructing significant bone defects is typically challenging. In the present study, two composite cements were used as scaffolds in a sub-critical femoral defect in rats. A control group and two experimental batches were used to compare the outcomes. This research aimed to investigate the osteogenic potential and toxicological tolerance of the bioproducts through histopathology and computed tomography imaging analysis at 14, 28, 56, and 90 days post-implantation. The biomaterials used in the investigation consisted of a 65% bioactive salinized inorganic filler and a 25% weight organic matrix. The organic part of the biomaterial was composed of Bis-GMA (bisphenol A-glycidyl methacrylate), UDMA (urethane dimethacrylate), HEMA (2-Hydroxyethyl methacrylate), and TEGDMA (triethylene glycol dimethacrylate), while the inorganic filler was composed of silica, barium glass, hydroxyapatite, and fluor aluminosilicate glass. The first findings of this research are encouraging, revealing that there is a slight difference between the groups treated with biomaterials, but it might be an effective approach for managing bone abnormalities. Material C1 exhibited a faster bone defect healing time compared to material C2, where bone fractures occurred in some individuals. It is unclear if the fractures were caused by the presence of the biomaterial C2 or whether additional variables were to blame. By the end of the research, the mice appeared to tolerate the biomaterials without exhibiting any inflammatory or rejection responses. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tissue engineering seeks to improve, maintain, or replace the biological functions of damaged organs or tissues with biological substitutes such as the development of scaffolds. In the case of bone tissue, they must have excellent mechanical properties like native bone. OBJECTIVE: In this work, three geometric models were designed for scaffolds with different structure lattices and porosity that could be biomechanically suitable and support cell growth for trabecular bone replacement applications in tissue engineering and regenerative medicine to the proximal femur area. METHODS: Geometries were designed using computer-aided design (CAD) software and evaluated using finite element analysis in compression tests. Three loads were considered according to the daily activity: 1177 N for slow walking, 2060 N for fast walking, and 245.25 N for a person in a bipedal position. All these loads for an adult weight of 75 kg. For each of them, three biomaterials were assigned: two polymers (poly-glycolic acid (PGA) and poly-lactic acid (PLA)) and one mineral (hydroxyapatite (HA)). 54 tests were performed: 27 for each of the tests. RESULTS: The results showed Young's modulus (E) between 1 and 4 GPa. CONCLUSION: If the resultant E is in the range of 0.1 to 5 GPa, the biomaterial is considered an appropriate alternative for the trabecular bone which is the main component of the proximal bone. However, for the models applied in this study, the best option is the poly-lactic acid which will allow absorbing the acting loads. [ABSTRACT FROM AUTHOR]

BACKGROUND: With the restoration of the natural hip biomechanics, a successful total hip arthroplasty (THA) and long-term survival is pursued. Although robotic THA (rTHA) has been developed to increase accuracy of implant positioning, leg lengths and offsets, discussions about its radiological and clinical advantages over conventional THA (cTHA) continues. OBJECTIVE: The aim of this study was to compare clinical and radiological outcomes of robotic and conventional THA. METHODS: This retrospective study compares functional and radiological outcomes of 82 rTHA with a matched group of 82 cTHA in terms of age, sex, body mass index and preoperative functional scores. The minimum follow up was 12 months for all patients. Functional outcomes were Harris Hip Score (HHS) and the Western Ontario and McMaster University Osteoarthritis index (WOMAC) evaluated pre- and postoperatively. Radiological evaluations included position of cup placement according to Lewinnek and Callanan safe zones, Canal Fill Ratio (CFR), Leg Length Discrepancy (LLD), Lateral offset (LO) and Femoral Component Alignment (FCA). Complications were also evaluated. RESULTS: In the rTHA group, 91.5% (75 out of 82) of the acetabular cups were positioned within the safe zone whereas it was 63.4% (52 out of 82) for the cTHA group (p < 0.001). According to Callanan, they were 84.1% and 50%, respectively (p < 0.001). Between the groups, no statistically significant difference was found in CFR, LLD, HO, FCA, AI, AA, WOMAC, HHS and major complication rates. CONCLUSION: rTHA is superior to cTHA in terms of accuracy and reproducibility of the cup placement, however no apparent clinical benefit was found in short term follow. [ABSTRACT FROM AUTHOR]

It is unclear whether the response in femoral cartilage to running at different intensities is different. To examine the acute patterns of deformation and recovery in femoral cartilage thickness during and after running at different speeds. Crossover study. Laboratory. A total of 17 healthy men (age = 23.9 ± 2.3 years, height = 173.1 ± 5.5 cm, mass = 73.9 ± 8.0 kg). Participants performed a 40-minute treadmill run at speeds of 7.5 and 8.5 km/h. Ultrasonographic images of femoral cartilage thickness (intercondylar, lateral condyle, and medial condyle) were obtained every 5 minutes during the experiment (40 minutes of running followed by a 60-minute recovery period) at each session. Data were analyzed using analysis of variance and Bonferroni- and Dunnett-adjusted post hoc t tests. To identify patterns of cartilage response, we extracted principal components (PCs) from the cartilage-thickness data using PC analysis, and PC scores were analyzed using t tests. Regardless of time, femoral cartilage thicknesses were greater for the 8.5-km/h run than the 7.5-km/h run (intercondylar: F1,656 = 24.73, P <.001, effect size, 0.15; lateral condyle: F1,649 = 16.60, P <.001, effect size, 0.16; medial condyle: F1,649 = 16.55, P <.001, effect size, 0.12). We observed a time effect in intercondylar thickness (F20,656 = 2.15, P =.003), but the Dunnett-adjusted post hoc t test revealed that none of the time point values differed from the baseline value (P >.38 for all comparisons). Although the PC1 and PC2 captured the magnitudes of cartilage thickness and time shift (eg, earlier versus later response), respectively, t tests showed that the PC scores were not different between 7.5 and 8.5 km/h (intercondylar: P ≥.32; lateral condyle: P ≥.78; medial condyle: P ≥.16). Although the 40-minute treadmill run with different speeds produced different levels of fatigue, morphologic differences (<3%) in the femoral cartilage at both speeds seemed to be negligible. [ABSTRACT FROM AUTHOR]

The aim of the present study was to examine the effects of attentional focus instructions on acute changes in the transverse relaxation time (T2) of the femorotibial cartilage and in cartilage volume during repeated drop‐jump landings. Ten healthy females (Mage = 20.4 ± 0.8 years) performed a drop landing task from a 50 cm high box over the course of 3 days (50 repetitions each day) across three attentional focus conditions: external focus (EF: focus on landing as soft as possible), internal focus (IF: focus on bending your knees when you land), and control (CON: no‐focus instruction), which was counterbalanced across focus conditions. T2 mapping and the volume of femorotibial cartilage were determined from magnetic resonance imaging scans at 1.5 T for the dominant knee before and after completing the drop landings in each attentional focus condition per day. Results indicated a smaller change in cartilage T2 relaxation time and volumetry in the central load‐bearing lateral cartilage under the EF, compared to IF and CON. Moreover, the change in T2 and cartilage volume was greater for lateral tibial cartilage as compared to femoral cartilage and was independent of attentional focus instructions. No significant acute quantitative changes were observed in the medial compartment. The peak vertical ground reaction force was found to be the lowest under the EF, compared to IF and CON. These findings suggest that external focus of attention may reduce cartilage load, potentially aiding in the control or management of cartilage injuries during landing in female athletes. [ABSTRACT FROM AUTHOR]

An experiment investigated the effects of early qualitative feed restriction and barrier perch provision on the morphometric and biomechanical measurements of the bones in broiler chickens. A total of 504 one-day-old Ross 308 male broiler chickens were randomly assigned to a completely randomized design with a 2×2 factorial arrangement (three replicate pens/group;42 chickens/pen) of qualitative feed restriction (presence- QFR+/absence-QFR-) and the provision of barrier perch (presence-BP+/absence-BP-). On days 21 and 42, morphometric and biomechanical parameters were measured. As a result of this study, barrier perch presence showed no significant impact on morphometric and biomechanical measurements. In the QFR- group, the weight and length of femur bones in 42-day-old broiler chickens were found to be higher (P<0.0001, P=0.034, respectively), alongside increased weight (P=0.001), inner (mediolateral P=0.002 and craniocaudal P=0.040) and outer (mediolateral P=0.047) diameter of the tibiotarsus bones. Furthermore, weight-length index values of the femur and tibiotarsus bones were higher (P=0.001, P<0.0001, respectively) in the QFR- group, while robusticity index values were lower (P=0.029, P=0.006, respectively) on the 42nd day. Regarding biomechanical parameters, the ultimate force level of tibiotarsus bones was statistically higher (P=0.030) at 42 days in the QFR- group. In summary, early protein and energy restriction caused slight decreases in some measurements of the femur and tibiotarsus bones. Strong correlations were observed between specific morphometric and biomechanical parameters, demonstrating their potential to predict biomechanical measurements. [ABSTRACT FROM AUTHOR]

Cam-type deformities of the proximal femur have long been associated with femoroacetabular impingement (FAI); an orthopedic condition recognized in the etiology of early osteoarthritis (OA) in the non-dysplastic adult hip. However, the optimal clinical management (including the long-term prognosis) of patients with cam-type deformities with or without FAI symptoms remains uncertain. In this imaging case review (ICR), we present the 10-year follow-up of a retired chiropractor with bilateral cam-type femoral deformities who initially underwent total right hip joint arthroplasty for advanced hip joint OA, and subsequently developed advanced hip joint OA on the contralateral side. [ABSTRACT FROM AUTHOR]

Background: Aseptic loosening is one of the leading causes of stem revision. Einzel Bild Röntgen Analyse–Femoral Component Analysis allows for the detection of distal stem migration, which is used as a predictive factor for implant longevity. This study aims to demonstrate the migration behavior of a cemented collared anatomical stem. Methods: This study retrospectively examined all patients who received a cemented Lubinus SP II stem (Waldemar Link, Hamburg, Germany) between 2003 and 2019. We used the EBRA-FCA software (University of Innsbruck, Austria) to determine the migration patterns and thoroughly examined the patients' medical histories. In addition, the potential influence of femoral configuration and BMI on the migration behavior was assessed. Results: This study included 61 patients (48 females and 13 males) with a total of 61 stems that met our inclusion criteria. The mean age at surgery was 76 years (ranging from 30 to 93 years). According to EBRA-FCA migration analysis, a median subsidence of 0.7 mm was observed at 24 months and at the final follow-up (median 78 months). Distal stem migration was significantly higher at the 6-month time point in patients with Dorr type A femurs compared to Dorr type B femurs (p = 0.016). Body mass index (BMI) had no significant effect on stem migration. Conclusions: The measured subsidence of the Lubinus SP 2 stem using EBRA-FCA was below established thresholds, indicating excellent long-term outcomes. Although there was significantly increased subsidence in Dorr type A femurs during the initial 6 months, thereafter, no statistically significant difference was observed compared to Dorr type B femurs. [ABSTRACT FROM AUTHOR]

Background Femoral version deformities have recently been identified as a major contributor to femoroacetabular impingement (FAI). An in-depth understanding of the specific labral damage patterns caused by femoral version deformities may help to understand the underlying pathomorphologies in symptomatic patients and select the appropriate surgical treatment. Questions/purposes We asked: (1) Is there a correlation between femoral version and the mean cross-sectional area of the acetabular labrum? (2) Is there a difference in the location of lesions of the acetabular labrum between hips with increased femoral version and hips with decreased femoral version? (3) Is there a difference in the pattern of lesions of the acetabular labrum between hips with increased femoral version and hips with decreased femoral version? Methods This was a retrospective, comparative study. Between November 2009 and September 2016, we evaluated 640 hips with FAI. We considered patients with complete diagnostic imaging including magnetic resonance arthrography (MRA) of the affected hip with radial slices of the proximal femur and axial imaging of the distal femoral condyles (allowing for calculation of femoral version) as eligible. Based on that, 97% (620 of 640 hips) were eligible; a further 77% (491 of 640 hips) were excluded because they had either normal femoral version (384 hips), incomplete imaging (20 hips), a lateral center-edge angle < 22° (43 hips) or > 39° (16 hips), age > 50 years (8 hips), or a history of pediatric hip disease (20 hips), leaving 20% (129 of 640 hips) of patients with a mean age of 27 ± 9 years for analysis, and 61% (79 of 129 hips) were female. Patients were assigned to either the increased (> 30°) or decreased (< 5°) femoral version group. The labral cross-sectional area was measured on radial MR images in all patients. The location-dependent labral cross-sectional area, presence of labral tears, and labral tear patterns were assessed using the acetabular clockface system and compared among groups. Results In hips with increased femoral version, the labrum was normal in size (21 ± 6 mm² [95% confidence interval 20 to 23 mm²]), whereas hips with decreased femoral version showed labral hypotrophy (14 ± 4 mm² [95% CI 13 to 15 mm²]; p < 0.01). In hips with increased femoral version, labral tears were located more anteriorly (median 1:30 versus 12:00; p < 0.01). Hips with increased femoral version exhibited damage of the anterior labrum with more intrasubstance tears anterosuperiorly (17% [222 of 1322] versus 9% [93 of 1084]; p < 0.01) and partial tears anteroinferiorly (22% [36 of 165] versus 6% [8 of 126]; p < 0.01). Hips with decreased femoral version showed superior labral damage consisting primarily of partial labral tears. Conclusion In the evaluation of patients with FAI, the term "labral tear" is not accurate enough to describe labral pathology. Based on high-quality radial MR images, surgeons should always evaluate the combination of labral tear location and labral tear pattern, because these may provide insight into associated femoral version abnormalities, which can inform appropriate surgical treatment. Future studies should examine symptomatic patients with normal femoral version, as well as an asymptomatic control group, to describe the effect of femoral version on labral morphology across the entire spectrum of pathomorphologies. Level of Evidence Level III, prognostic study. [ABSTRACT FROM AUTHOR]

Background: The effect of swimming on bone health remains unclear, namely due to discrepant findings between studies in humans and animal models. Objective: The aim of this systematic review and meta-analysis is to identify the available evidence on the effects of swimming on bone mass, geometry and microarchitecture at the lumbar spine, femur and tibia in both humans and rodent animal models. Methods: The study followed PRISMA guidelines and was registered at PROSPERO (CRD4202236347 and CRD42022363714 for human and animal studies). Two different systematic literature searches were conducted in PubMed, Scopus and Web of Science, retrieving 36 and 16 reports for humans and animal models, respectively. Results: In humans, areal bone mineral density (aBMD) was similar between swimmers and non-athletic controls at the lumbar spine, hip and femoral neck. Swimmers' tibia diaphysis showed a higher cross-sectional area but lower cortical thickness. Inconsistent findings at the femoral neck cortical thickness were found. Due to the small number of studies, trabecular microarchitecture in human swimmers was not assessed. In rodent models, aBMD was found to be lower at the tibia, but similar at the femur. Inconsistent findings in femur diaphysis cross-sectional area were observed. No differences in femur and tibia trabecular microarchitecture were found. Conclusion: Swimming seems to affect bone health differently according to anatomical region. Studies in both humans and rodent models suggest that tibia cortical bone is negatively affected by swimming. There was no evidence of a negative effect of swimming on other bone regions, both in humans and animal models. [ABSTRACT FROM AUTHOR]

Introduction: fixation of unstable intertrochanteric fractures presents a significant challenge, especially in the context of osteoporosis. Intramedullary implants have been established as superior to plate constructs. Our aim is to compare the complications and clinical outcomes of the Proximal Femur Nail (PFN) and Proximal Femur Nail Antirotation-2 (PFNA2) in managing unstable intertrochanteric fractures. Material and methods: a total of 212 patients meeting inclusion and exclusion criteria underwent fixation of trochanteric fractures using either a standard PFN (n = 110) or PFNA2 (n = 102). Their intraoperative and postoperative clinical and radiographic data were evaluated along with the quality of fixation. Data analysis was performed using the student's t-test, χ² test, and Mann-Whitney U test. Results: PFNA2 demonstrated more favorable outcomes compared to PFN in terms of a better intraoperative profile, functional outcomes (PFNA2: PFN = 82:75), and fewer implant-related complications. Significant issues in the PFN group included screw backout, guidewire breakage, and proximal protrusion of the nail tip. In contrast, locking mechanism failure and lateral screw prominence were significant problems in the PFNA2 group. Conclusion: PFNA2 is the preferred implant for managing osteoporotic unstable intertrochanteric fractures, given the bone's weak inherent tendency to secure the implant. [ABSTRACT FROM AUTHOR]

Geometric morphometrics (GMM) have been applied to understand morphological variation in biological structures. However, research studying cortical bone through geometric histomorphometrics (GHMM) is scarce. This research aims to develop a landmark‐based GHMM protocol to depict osteonal shape variation in the femoral diaphysis, exploring the role of age and biomechanics in bone microstructure. Proximal, midshaft, and distal anatomical segments from the femoral diaphysis of six individuals were assessed, with 864 secondary intact osteons from eight periosteal sampling areas being manually landmarked. Observer error was tested using Procrustes ANOVA. Average osteonal shape and anatomical segment‐specific variation were explored using principal component analysis. Osteon shape differences between segments were examined using canonical variate analysis (CVA). Sex differences were assessed through Procrustes ANOVA and discriminant function analysis (DFA). The impact of osteonal size on osteonal shape was investigated. High repeatability and reproducibility in osteon shape landmarking were reported. The average osteon shape captured was an elliptical structure, with PC1 reflecting more circular osteons. Significant differences in osteon shape were observed between proximal and distal segments according to CVA. Osteon shape differed between males and females, with DFA showing 52% cross‐validation accuracies. No effect of size on shape was reported. Osteonal shape variation observed in this study might be explained by the elderly nature of the sample as well as biomechanical and physiological mechanisms playing different roles along the femoral diaphysis. Although a larger sample is needed to corroborate these findings, this study contributes to the best of our knowledge on human microanatomy, proposing a novel GHMM approach. [ABSTRACT FROM AUTHOR]

Objectives: Our aim was to predict the prevalence of osteopenia and osteoporosis and their associated risk factors among postmenopausal women from Jordan. Methodology: In this cross‐sectional study, a total of 368 postmenopausal women were recruited from King Abdullah University Hospital (KAUH) in the North of Jordan between September 2022 and April 2023. Bone mineral density (BMD) was measured using a dual‐energy X‐ray absorptiometry scan. T‐score was used for osteoporosis diagnosis in accordance with the International Society for Clinical Densitometry (ISCD) guidelines. Data about sociodemographic and lifestyle variables were collected using face‐to‐face interviews. Medical records were used to retrieve participants' BMD information. Predictors of osteoporosis were identified using logistic regression. Results: Prevalence of osteoporosis was 40.5%, while 44.6% of participants were diagnosed with osteopenia. The lumbar spine had the highest frequency of osteoporosis (30.4%), while the left femoral neck had the highest prevalence of osteopenia (46.3%). Postmenopausal women's age (p‐value =.024), and history of chronic diseases (p‐value =.038) were significant factors associated with increased osteoporosis risk. Conclusions: Postmenopausal women from Jordan had high prevalence of osteoporosis and osteopenia. It is therefore necessary to target risk factors leading to osteoporosis and to improve patients' lifestyles through patient education. Healthcare systems should consider early screening approaches for osteoporosis at the age of menopause and thereafter. Supplements of calcium and vitamin D may be routinely considered for this age group depending on their serum levels. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate whether double‐level (femur + tibia) derotational osteotomy is superior to single‐level femoral derotational osteotomy for recurrent patellar dislocation with severe femoral and tibial rotational deformities (femoral anteversion >30° and external tibial torsion >30°). Methods: Between January 2015 and June 2020, a total of 115 knees with recurrent patellar dislocation treated with combined medial patellofemoral ligament reconstruction (MPFL‐R) and derotational osteotomies were evaluated after a minimum follow‐up of 2 years. Among these cases, 15 knees that underwent double‐level derotational osteotomy were included in the double‐level group, which was propensity‐matched in a 1:2 ratio to a single‐level group of patients who underwent single‐level femoral derotational osteotomy (30 knees). The clinical and radiological outcomes were evaluated and compared between the groups. Furthermore, the foot progression angle was measured preoperatively and 2 years after surgery. Results: The patient‐specific variables did not differ significantly between the double‐ and the single‐level groups after propensity score matching. The postoperative mean foot progression angle was significantly lower in the double‐level group than in the single‐level group (9° ± 8° vs. 15° ± 11°; p = 0.014); however, there were no statistically significant differences between the groups in terms of any other clinical and radiological assessments. Conclusion: For patients with severe femoral and tibial torsional deformities (femoral anteversion >30° and external tibial torsion >30°), the double‐level derotational osteotomy is superior to single‐level osteotomy in maintaining normal foot progression angle, but it does not show an advantage in terms of patient‐reported outcomes, radiological results and redislocation rate at minimum 2 years of follow‐up. Furthermore, concomitant excessive external tibial torsion (>30°) did not have an adverse effect on clinical outcomes in patients who underwent derotational distal femoral osteotomy with MPFL‐R due to excessive femoral anteversion. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: Implant loosening represent the most common indication for stem revision in hip revision arthroplasty. This study compares femoral bone loss and the risk of initial revisions between cemented and uncemented loosened primary stems, investigating the impact of fixation method at primary implantation on femoral bone defects. Methods: This retrospective study reviewed 255 patients who underwent their first revision for stem loosening from 2010 to 2022, receiving either cemented or uncemented stem implants. Femoral bone loss was preoperatively measured using the Paprosky classification through radiographic evaluations. Kaplan-Meier analysis estimated the survival probability of the original stem, and the hazard ratio assessed the relative risk of revision for uncemented versus cemented stems in the first postoperative year and the following two to ten years. Results: Cemented stems showed a higher prevalence of significant bone loss (type 3b and 4 defects: 32.39% vs. 2.72%, p <.001) compared to uncemented stems, which more commonly had type 1 and 2 defects (82.07% vs. 47.89%, p <.001). In our analysis of revision cases, primary uncemented stems demonstrated a 20% lower incidence of stem loosening in the first year post-implantation compared to cemented stems (HR 0.8; 95%-CI 0.3-2.0). However, the incidence in uncemented stems increased by 20% during the subsequent years two to ten (HR 1.2; 95%-CI 0.7–1.8). Septic loosening was more common in cemented stems (28.17% vs. 10.87% in uncemented stems, p =.001). Kaplan-Meier analysis indicated a modestly longer revision-free period for cemented stems within the first ten years post-implantation (p <.022). Conclusion: During first-time revision, cemented stems show significantly larger femoral bone defects than uncemented stems. Septic stem loosening occurred 17.30% more in cemented stems. [ABSTRACT FROM AUTHOR]

Purpose: Manual reconstruction (MR) of the vastus lateralis (VL) muscle cross-sectional area (CSA) from sequential ultrasound (US) images is accessible, is reproducible, and has concurrent validity with magnetic resonance imaging. However, this technique requires numerous controls and procedures during image acquisition and reconstruction, making it laborious and time-consuming. The aim of this study was to determine the concurrent validity of VL CSA assessments between MR and computer vision--based automated reconstruction (AR) of CSA from sequential images of the VL obtained by US. Methods: The images from each sequence were manually rotated to align the fascia between images and thus visualize the VL CSA. For the AR, an artificial neural network model was utilized to segment areas of interest in the image, such as skin, fascia, deep aponeurosis, and femur. This segmentation was crucial to impose necessary constraints for the main assembly phase. At this stage, an image registration application, combined with differential evolution, was employed to achieve appropriate adjustments between the images. Next, the VL CSA obtained from the MR (n = 488) and AR (n = 488) techniques was used to determine their concurrent validity. Results: Our findings demonstrated a low coefficient of variation (CV) (1.51%) for AR compared with MR. The Bland--Altman plot showed low bias and close limits of agreement (+1.18 cm², -1.19 cm²), containing more than 95% of the data points. Conclusions: The AR technique is valid compared with MR when measuring VL CSA in a heterogeneous sample. [ABSTRACT FROM AUTHOR]

Benign, locally aggressive tumors of the distal femur are typically treated with intralesional curettage and polymethylmethacrylate (PMMA) cementation. However, it is not known whether plate fixation should be added to biomechanically augment these PMMA‐filled defects. The purpose of this study was to evaluate the performance of two competing techniques for reconstruction of a distal femoral defect. For this biomechanical study, we used 12 composite femurs with properties comparable to bone. In nine femurs, identical contained medial distal femoral defects were created using a robotic arm. Group A contained three intact femurs, Group B three femurs with an unfilled defect, Group C three femurs reconstructed with PMMA alone, and Group D three femurs reconstructed with PMMA plus a medial locking plate. Locations of greatest stress concentration were determined by PhotoStress analysis, then three strain gauges were applied to each specimen at these high‐stress locations. Specimens were loaded within a physiologic range followed by loading to failure. Outcome measures included construct stiffness, strain along the distal femur, and load at failure. Results showed that stiffness and strain were not significantly different between reconstructive techniques; however, both techniques reduced tensile strain along the popliteal surface by approximately 40% compared to non‐reconstructed specimens. All specimens failed at the femoral neck before failing at the distal femur. These findings suggest that plate augmentation of PMMA‐filled distal femoral defects like the one in this study offers insignificant biomechanical benefit within physiologic loads and therefore may be unnecessary. [ABSTRACT FROM AUTHOR]