BACKGROUND: Falls due to stumbling are prevalent for transfemoral prosthesis users and may lead to increased injury risk. This preliminary case series analyzes the transfemoral prosthesis user stumble recovery response to highlight key deficits in current commercially-available prostheses and proposes potential interventions to improve recovery outcomes.
METHODS: Six transfemoral prosthesis users were perturbed on their prosthetic limb at least three times while walking on a treadmill using obstacle perturbations in early, mid and late swing. Kinematic data were collected to characterize the response, while fall rate and key kinematic recovery metrics were used to assess the quality of recovery and highlight functional deficits in current commercially-available prostheses.
RESULTS: Across all participants, 13 (54%) of the 24 trials resulted in a fall (defined as > 50% body-weight support) with all but one participant (83%) falling at least once and two participants (33%) falling every time. In contrast, in a previous study of seven young, unimpaired, non-prosthesis users using the same experimental apparatus, no falls occurred across 190 trials. For the transfemoral prosthesis users, early swing had the highest rate of falling at 64%, followed by mid-swing at 57%, and then late swing at 33%. The trend in falls was mirrored by the kinematic recovery metrics (peak trunk angle, peak trunk angular velocity, forward reach of the perturbed limb, and knee angle at ground contact). In early swing all four metrics were deficient compared to non-prosthesis user controls. In mid swing, all but trunk angular velocity were deficient. In late swing only forward reach was deficient.
CONCLUSIONS: Based on the stumble recovery responses, four potential deficiencies were identified in the response of the knee prostheses: (1) insufficient resistance to stance knee flexion upon ground contact; (2) insufficient swing extension after a perturbation; (3) difficulty initiating swing flexion following a perturbation; and (4) excessive impedance against swing flexion in early swing preventing the potential utilization of the elevating strategy. Each of these issues can potentially be addressed by mechanical or mechatronic changes to prosthetic design to improve quality of recovery and reduce the likelihood a fall.

BACKGROUND: The rotational change after using a flexible intramedullary (IM) nail for femoral shaft fractures has been a concern for many surgeons. Recently, a statistical shape model (SSM) was developed for the three-dimensional reconstruction of the femur from two-dimensional plain radiographs. In this study, we measured postoperative femoral anteversion (FAV) in patients diagnosed with femoral shaft fractures who were treated with flexible IM nails and investigated age-related changes in FAV using the SSM.
METHODS: This study used radiographic data collected from six regional tertiary centers specializing in pediatric trauma in South Korea. Patients diagnosed with femoral shaft fractures between September 2002 and June 2020 and patients aged < 18 years with at least two anteroposterior (AP) and lateral (LAT) femur plain radiographs obtained at least three months apart were included. A linear mixed model (LMM) was used for statistical analysis.
RESULTS: Overall, 72 patients were included in the study. The average patient age was 7.6 years and the average follow-up duration was 6.8 years. The average FAV of immediate postoperative images was 27.5 ± 11.5°. Out of 72 patients, 52 patients (72.2%) showed immediate postoperative FAV greater than 20°. The average FAV in patients with initial FAV > 20° was 32.74°, and the LMM showed that FAV decreased by 2.5° (p = 0.0001) with each 1-year increase from the time of initial trauma.
CONCLUSIONS: This study explored changes in FAV after femoral shaft fracture using a newly developed technology that allows 3D reconstruction from uncalibrated 2D images. There was a pattern of change on the rotation of the femur after initial fixation, with a 2.5° decrease of FAV per year.

Aside from human bones, epoxy-based synthetic bones are regarded as the gold standard for biomechanical testing os osteosyntheses. There is a significant discrepancy in biomechanical testing between the determination of fracture stability due to implant treatment in experimental methods and their ability to predict the outcome of stability and fracture healing in a patient. One possible explanation for this disparity is the absence of population-specific variables such as age, gender, and ethnicity in artificial bone, which may influence the geometry and mechanical properties of bone. The goal of this review was to determine whether commercially available artificial bones adequately represent human anatomical variability for mechanical testing of femoral osteosyntheses. To summarize, the availability of suitable bone surrogates currently limits the validity of mechanical evaluations of implant-bone constructs. The currently available synthetic bones neither accurately reflect the local mechanical properties of human bone, nor adequately represent the necessary variability between various populations, limiting their generalized clinical relevance.

BACKGROUND: This study aimed to develop a novel deep convolutional neural network called Dual-path Double Attention Transformer (DDA-Transformer) designed to achieve precise and fast knee joint CT image segmentation and to validate it in robotic-assisted total knee arthroplasty (TKA).
METHODS: The femoral, tibial, patellar, and fibular segmentation performance and speed were evaluated and the accuracy of component sizing, bone resection and alignment of the robotic-assisted TKA system constructed using this deep learning network was clinically validated.
RESULTS: Overall, DDA-Transformer outperformed six other networks in terms of the Dice coefficient, intersection over union, average surface distance, and Hausdorff distance. DDA-Transformer exhibited significantly faster segmentation speeds than nnUnet, TransUnet and 3D-Unet (p < 0.01). Furthermore, the robotic-assisted TKA system outperforms the manual group in surgical accuracy.
CONCLUSIONS: DDA-Transformer exhibited significantly improved accuracy and robustness in knee joint segmentation, and this convenient and stable knee joint CT image segmentation network significantly improved the accuracy of the TKA procedure.

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.

UNASSIGNED: A plain pelvic radiograph is usually conducted with the lower limbs in internal rotation. This is to correct the anteversion of the femur. However, in the fracture neck of the femur, internal rotation of the fractured limb is avoided, because it would be painful. We examined the effect of correction of anteversion or otherwise on the diameter of the head of the femur using imaging.
UNASSIGNED: This study aimed to determine if there was a significant difference between the femoral head diameter at two different positions, at the normal anatomical position (without correcting the anteversion) and at the corrected anteversion position. It also aimed to document the correlation and the statistical significance between the differences in the size of the diameter at these two different positions with the anteversion angles of the femoral bone.
UNASSIGNED: Two sets of digital photographs of the proximal part of 55 non-sexed, non-paired femoral bones were taken. Images obtained were at two positions: normal anatomical (with anteversion uncorrected) and anteversion corrected positions. The diameters of the head of the femur were documented at these two different positions. The anteversion angles and actual femoral head (AFH) diameters were also measured and documented.
UNASSIGNED: The femoral head diameters at anatomical positions were persistently larger than those measured after the anteversion was corrected, except in three femoral bones (5%) where no differences were observed. The difference in the two measurements was statistically significant to the anteversion angle of the femoral bone. (P = 0.0005). The means of the two sets of measurements were statistically different from each other. Pairwise correlation showed that both were strongly associated with the AFH diameter but the measurements from images with corrected anteversion had a higher value (0.8166) than the measurements from normal anatomical position (0.7526).
UNASSIGNED: The correction of femoral anteversion produced femoral head size measurements that were closer to AFH diameters compared to those without the correction of the femoral anteversion. Femoral anteversion should always be corrected as per protocol.

OBJECTIVE: Parosteal Osteosarcoma is a well-differentiated, low-grade bone sarcoma. It most commonly occurs in the third decade of life, usually in the distal femur. This study aims to perform a literature review about the types of reconstructions reported and to analyze the results of an updated technique of resection using custom-made 3D-printed cutting guides.
METHODS: We perform a systematic literature review about parosteal osteosarcoma, evaluating treatments, margins, local recurrence, complications, and functional results when available. We also report a case treated in our Center with a revisited technique introducing custom-made 3D-printed cutting guides.
RESULTS: We analyzed 12 studies with a total of 151 patients. The distal femur was the most frequently reported site (81.5%). After distal femur resection, reconstruction was performed with graft in most cases (48%), followed by prosthetic reconstruction (40%). Margins were wide in 85.5% of cases. The total incidence of local recurrence was 11%. Functional results were excellent in all cases, with a mean MSTS score of 86%. In our case, with the help of the jigs, the surgical technique was relatively easy, graft fusion excellent and fast, margins wide, and functional results excellent.
CONCLUSIONS: In the literature, the most commonly used type of reconstruction after resection is biological with graft. Indeed, despite the increasing number of prosthetic reconstructions, the historical diaphysometaphyseal hemiresection and graft is still indicated in parosteal osteosarcoma of the distal femur. New technologies, such as the jigs we used, allow significant advantages during the procedure: reduce the resection and graft preparation time, allow a better match between components, and help to obtain safer margins, sparing as much bone as possible.

UNASSIGNED: Paediatric femoral shaft fractures can be managed with single- or double-leg hip spica casting between ages six-months and six-years. The aim of this review was to determine if single-leg hip spicas reduce the impact on family life without compromising fracture stability.
UNASSIGNED: The study was registered on PROSPERO (CRD42023454309). MEDLINE, Embase, Web of Science, Cochrane Library, and clinical trial registers were searched to May 2023 for level I-III evidence. Primary outcomes were impact on family life and fracture stability. Where appropriate, Meta-analysis was completed using RevMan v5.4. Risk of bias was assessed using RoB 2.0 (RCTs) and ROBINS-I (non-RCTs). Certainty of evidence was measured with GRADE.
UNASSIGNED: From 234 identified papers, four met the inclusion criteria (two RCTs; two non-RCTs). A total of 339 children were included (single-leg spica: 176; double-leg spica: 163). Three studies were \'high risk\' and one study \'moderate risk\' of bias. Impact on family life parameters were too heterogenous for pooled meta-analysis. Non-pooled data identified significantly more missed work days in the double-leg spica group and the \'Impact on Family\' Scale significantly favoured single-leg spicas. For fracture stability, meta-analysis identified that (i) mal-union rates were significantly lower in single-leg spica: OR 0.08 (95 % CI 0.01 to 0.69; p = 0.02); (ii) MUA in theatre was not significantly different: OR 0.97 (95 % CI 0.19 to 4.86; p = 0.97); and (iii) wedge adjustment was not significantly different: OR 3.46 (95 % CI 0.48 to 24.92; p = 0.22). Certainty of evidence was assessed as \'very low\'.
UNASSIGNED: Single-leg hip spicas may be associated with reduced impact on family life without compromising fracture stability compared with double-leg hip spicas. However, the evidence is weak. Therefore, a propensity score matched observational study is required to understand if subgroups of patients (age, fracture pattern, mechanism of injury) would benefit from a single- or double-leg hip spica.

OBJECTIVE: There were few reports in the literature regarding hidden blood loss following surgery for developmental dysplasia of the hip in children. This study aimed to evaluate the volume of hidden blood loss and its risk factors among children undergoing hip reconstruction for developmental dysplasia of the hip.
METHODS: A retrospective analysis of clinical data from 42 patients (58 hips), who underwent Pemberton and femoral osteotomies between March 2020 and March 2023, was conducted. Serial complete blood count assays were conducted on the day of admission and four days post-surgery. Preoperative and postoperative hematocrit levels were documented to calculate hidden blood loss utilizing the Gross formula. Pearson and Spearman correlation analyses, along with multivariable linear regression, were employed to ascertain associations between patient characteristics and hidden blood loss.
RESULTS: The mean hidden blood loss was recorded as 283.06 ± 271.05 mL, constituting 70.22% of the total blood loss. Multiple linear regression analysis identified weight and surgical duration as independent risk factors contributing to hidden blood loss.
CONCLUSIONS: A relevant amount of postoperative hidden blood loss occurs after Pemberton osteotomy and femoral osteotomy for developmental dysplasia of the hip. Surgeons should be aware that patients who require blood transfusions and have longer surgical durations are at a higher risk of developing more hidden blood loss. Therefore, attention should be given to hidden blood loss to ensure patient safety during the perioperative period for those undergoing Pemberton and femoral osteotomies.
METHODS: IV.

BACKGROUND: This experimental study aimed at directly comparing conventional and endoscopic-assisted curettage towards (1) amount of residual tumour tissue (RTT) and (2) differences between techniques regarding surgical time and surgeons\' experience level.
METHODS: Three orthopaedic surgeons (trainee, consultant, senior consultant) performed both conventional (4x each) and endoscopic-assisted curettages (4x each) on specifically prepared cortical-soft cancellous femur and tibia sawbone models. \"Tumours\" consisted of radio-opaque polyurethane-based foam injected into prepared holes. Pre- and postinterventional CT-scans were carried out and RTT assessed on CT-scans. For statistical analyses, percentage of RTT in relation to total lesion\'s volume was used. T-tests, Wilcoxon rank-sum tests, and Kruskal-Wallis tests were applied to assess differences between surgeons and surgical techniques regarding RTT and timing.
RESULTS: Median overall RTT was 1% (IQR 1 - 4%). Endoscopic-assisted curettage was associated with lower amount of RTT (median, 1%, IQR 0 - 5%) compared to conventional curettage (median, 4%, IQR 0 - 15%, p = 0.024). Mean surgical time was prolonged with endoscopic-assisted (9.2 ± 2.9 min) versus conventional curettage (5.9 ± 2.0 min; p = 0.004). No significant difference in RTT amount (p = 0.571) or curetting time (p = 0.251) depending on surgeons\' experience level was found.
CONCLUSIONS: Endoscopic-assisted curettage appears superior to conventional curettage regarding complete tissue removal, yet at expenses of prolonged curetting time. In clinical practice, this procedure may be reserved for cases at high risk of recurrence (e.g. anatomy, histology).