BACKGROUND: Ongoing lower extremity long-bone nonunion is a devastating condition and associated with substantial patient morbidity. There is limited evidence regarding physical and mental function after surgical management of lower extremity nonunions. The purpose of this study was to assess general physical and mental health and lower extremity specific physical function of patients that underwent surgery for a lower extremity long-bone nonunion.
METHODS: One-hundred and twenty-four adult patients who underwent successful surgical management for a lower extremity long-bone nonunion between June 2002 and December 2021 were evaluated at an average follow-up of 8.6 years (interquartile range [IQR]: 4 - 12). General physical and mental health was assessed with the Short-Form 12 (SF-12) physical (PCS) and mental (MCS) component summaries, and lower extremity specific physical function with the Lower Extremity Functional Scale (LEFS). Multivariable linear regression was performed to identify variables that were independently associated with outcomes.
RESULTS: The median LEFS was 50 (IQR: 37 - 63) and the median SF-12 PCS was 43 (IQR: 33 - 52), which are both lower than normative population scores (LEFS: 77 and PCS: 51, p < 0.0001). The median SF-12 MCS was 50, which was comparable to the normative population score of 51 (p < 0.0001). The number of previous surgeries before the index nonunion treatment (p = 0.018 and p = 0.041) and the number of revision surgeries after the index nonunion treatment (p = 0.022 and p = 0.041) were associated with lower LEFS and SF-12 PCS scores.
CONCLUSIONS: At an average of 8.6 years after lower extremity nonunion surgery that led to bone healing, patients continue to report lower general and lower extremity specific physical functioning compared to the normative population. The number of surgical attempts to obtain definitive healing was associated with compromised physical function scores. Mental health scores may return close to normative population scores. These results can be used to inform patients and guide treatment strategies and healthcare policies.

BACKGROUND: Metastases increase the risk of fracture when affecting the femur. Consequently, clinicians need to know if the patient\'s femur can withstand the stress of daily activities. The current tools used in clinics are not sufficiently precise. A new method, the CT-scan-based finite element analysis, gives good predictive results. However, none of the existing models were tested for reproducibility. This is a critical issue to address in order to apply the technique on a large cohort around the world to help evaluate bone metastatic fracture risk in patients. The aim of this study is then to evaluate 1) the reproducibility 2) the transposition of the reproduced model to another dataset and 3) the global sensitivity of one of the most promising models of the literature (original model).
METHODS: The model was reproduced based on the paper describing it and discussion with authors to avoid reproduction errors. The reproducibility was evaluated by comparing the results given in the original model by the original first team (Leuven, Belgium) and the reproduced model made by another team (Lyon, France) on the same dataset of CT-scans of ex vivo femurs. The transposition of the model was evaluated by comparing the results of the reproduced model on two different datasets. The global sensitivity analysis was done by using the Morris method and evaluates the influence of the density calibration coefficient, the segmentation, the orientations and the length of the femur.
RESULTS: The original and reproduced models are highly correlated (r2 = 0.95), even though the reproduced model gives systematically higher failure loads. When using the reproduced model on another dataset, predictions are less accurate (r2 with the experimental failure load decreases, errors increase). The global sensitivity analysis showed high influence of the density calibration coefficient (mean variation of failure load of 84 %) and non-negligible influence of the segmentation, orientation and length of the femur (mean variation of failure load between 7 and 10 %).
CONCLUSIONS: This study showed that, although being validated, the reproduced model underperformed when using another dataset. The difference in performance depending on the dataset is commonly the cause of overfitting when creating the model. However, the dataset used in the original paper (Sas et al., 2020a) and the Leuven\'s dataset gave similar performance, which indicates a lesser probability for the overfitting cause. Also, the model is highly sensitive to density parameters and automation of measurement may minimize the uncertainty on failure load. An uncertainty propagation analysis would give the actual precision of such model and improve our understanding of its behavior and is part of future work.

UNASSIGNED: Total hip arthroplasty (THA) in patients with hypoplastic femurs presents a significant challenge to orthopedic surgeons due to the limited space available for implant placement. Therefore, the extra-small femoral stems have been proposed as a solution to this problem, but there are limited data on the outcomes. We aimed to evaluate clinical and radiological outcomes of THA in patients with extremely hypoplastic femurs using the Bencox CM stem (Corentec), an extra-small femoral stem.
UNASSIGNED: We included 6 hips from 4 patients. The mean age of the patients was 41.2 years (range, 19.6-60.4 years). The mean height was 135.1 cm (range, 113.6-150.0 cm) with a mean body mass index of 25.7 kg/m2 (range, 21.3-31.1 kg/m2). The diagnoses for THA were sequelae of septic arthritis in childhood, pseudoachondroplasia, spondyloepiphyseal dysplasia, and juvenile rheumatoid arthritis. Preoperative computed tomography scans were conducted to assess the extent of proximal femoral hypoplasia. The clinical outcomes were assessed using the modified Harris Hip Score, while the radiological outcomes were evaluated using radiographs. The mean follow-up was 2.3 years (range, 1.0-5.9 years).
UNASSIGNED: The average modified Harris Hip Score improved to 88.8 at the final follow-up. Intraoperative femoral fractures occurred in 2 cases (33.3%). During the follow-up, 1 stem underwent varus tilting from postoperative 6 weeks to 6 months without subsidence. Otherwise, all stems showed good osteointegration at the latest follow-up. No hip dislocations, periprosthetic joint infection, or loosening of the prosthesis occurred.
UNASSIGNED: The use of extra-small femoral stems in THA for extremely hypoplastic femurs can provide reasonable clinical and radiological outcomes with minimal complications. We suggest that this femoral stem could be a viable option for patients with extremely hypoplastic femurs.

BACKGROUND: Curved varus osteotomy (CVO) is an effective femoral head-preserving surgical procedure for osteonecrosis of the femoral head (ONFH) classified as type B or C1 according to the Japanese Investigation Committee (JIC) classification; it reportedly provides better postoperative outcomes than transtrochanteric rotational osteotomy (TRO). We have developed a new procedure called spherical varus rotational osteotomy (SVRO) in which osteotomy of the femur into a spherical shape is followed by varus and anterior rotation using navigation to increase indications and improve postoperative outcomes.
METHODS: Nine joints of eight patients who underwent SVRO and could be followed up for > 1 year were included in the study. Disease types determined preoperatively according to the JIC classification were type C1 for four joints and type C2 for five joints. Preoperative disease JIC classification stages were 3a for eight joints and 1 for one joint. SVRO was performed using OrthoMap® 3D Navigation software, and the following variables were measured: surgery time, intraoperative blood loss, difference between preoperative and postoperative angles of anteversion, postoperative lower limb length discrepancy, and postoperative intact area occupancy. The Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) was used for clinical evaluation. Visual Analog Scale and JHEQ scores were evaluated preoperatively and at the final follow-up.
RESULTS: The measurement results were as follows: surgery time, 130 min; blood loss, 200 ml; angle of varus, 20°; angle of anterior rotation, 30°; preoperative angle of anteversion, 15°; postoperative angle of anteversion, 22°; lower limb shortening, 11 mm; preoperative intact area occupancy, 0%; and postoperative intact area occupancy, 74.2%. There were no cases of progression in the postoperative stages or re-collapse.
CONCLUSIONS: SVRO allows for the repositioning of the exterior and posterior intact areas, providing a broader intact region postoperatively. This technique is particularly beneficial for young patients with ONFH and extensive necrosis and is a less invasive alternative to TRO. This procedure has been shown to be effective in achieving favorable outcomes in patients with extensive necrosis who would have otherwise required rotational osteotomy, depending on the necrosis location. Further longitudinal studies are necessary to validate these findings and establish long-term benefits.

UNASSIGNED: The aim of this study was to compare the migration of the femoral component, five years postoperatively, between patients with a highly cross-linked polyethylene (HXLPE) insert and those with a conventional polyethylene (PE) insert in an uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary aims included clinical outcomes and patient-reported outcome measures (PROMs). We have previously reported the migration and outcome of the tibial components in these patients.
UNASSIGNED: A double-blinded randomized controlled trial was conducted including 96 TKAs. The migration of the femoral component was measured with radiostereometry (RSA) at three and six months and one, two, and five years postoperatively. PROMs were collected preoperatively and at all periods of follow-up.
UNASSIGNED: There was no clinically relevant difference in terms of migration of the femoral component or PROMs between the HXLPE and PE groups. The mean difference in migration (maximum total point motion), five years postopeatively, was 0.04 mm (95% CI -0.06 to 0.16) in favour of the PE group.
UNASSIGNED: There was no clinically relevant difference in migration of the femoral component, for up to five years between the two groups. These findings will help to establish a benchmark for future studies on migration of femoral components in TKA.

Critical bone loss can have several origins: infections, tumors or trauma. Therefore, massive bone allograft can be a solution for limb salvage. Such a biological reconstruction should have the ideal biomechanical qualities. However, their complication rate remains too high. Perfusion-decellularization of massive allografts could promote the vitality of these grafts, thereby improving their integration and bone remodeling. Three perfusion-decellularized massive bone allografts were compared to 3 fresh frozen massive bone allografts in a preclinical in vivo porcine study using an orthopedic surgery model. Three pigs each underwent a critical diaphyseal femoral defects followed by an allogeneic intercalary femoral graft on their both femurs (one decellularized and one conventional fresh frozen as \"native\") to reconstruct the defect. Clinical imaging was performed over 3 months of follow-up. The grafts were then explanted and examined by non-decalcified histology, fluoroscopic microscopy and immunohistochemistry. Bone consolidation was achieved in both groups at the same time. However, the volume of bone callus appeared to be greater in the decellularized group. Histology demonstrated a superior bone remodeling in the decellularized group, with a higher number of osteoclasts (p < 0.001) and larger areas of osteoid matrix and newly formed bone as compared to the \"native\" group. Immunohistochemistry showed a superior vitality and remodeling in both the cortical and medullary cavities for osteocalcin (p < 0.001), Ki67 (p < 0.001), CD3 (p < 0.001) and α-SMA (p < 0.001) as compared the \"native\" group. Three months after implantation, the decellularized grafts were proven to be biologically more active compared to native grafts. Fluoroscopic microscopy revealed more ossification fronts in the depth of the decellularized grafts (p = 0.021). This pilot study provides the first in vivo demonstration on the enhanced biological capacities of massive bone allograft decellularized by perfusion as compared to conventional massive bone allografts.

BACKGROUND: The femur is a common site for Multiple Myeloma (MM) involvement. This study explores the impact of preventive surgery for anticipated femoral pathological fractures (IFF), based on Mirels classification, versus treatment of pathological femur fracture (PFF) on MM patient mortality and morbidity.
METHODS: Retrospective cohort of 33 patients undergoing surgery due to femoral MM involvement (2004-2015), 18 patients with PFF, 15 patients with IFF, followed up until deceased or to July 2016. Demographic data, oncological, pathological, radiation, surgical reports, outpatient clinical records, and imaging studies were studied. Exclusion criteria included patients who had surgery at other medical centers.
RESULTS: The mean age was 70.4 ± 13.6 and 62.6 ± 12.2 years (p = 0.1) in the PFF and the IFF cohorts, respectively, primarily women (55.6% and 46.7%, respectively). The average Mirels\' score was 10.4 ± 1.2. Post-operative complications were observed in 25% of patients, with no difference between IFF & PFF. We did not find a difference in mortality between IFF and PFF cohorts (p = 0.59).
CONCLUSIONS: The femur is commonly involved in MM. This study found that actual fractures, compared to imminent fractures, do not affect MM morbidity or mortality. Our study shows that proximal femoral MM behaves differently from proximal femoral metastatic disease regarding the impact of surgery on life span. Due to the fracture healing potential of MM, an IFF can probably be treated initially conservatively unless it progresses to an actual fracture needing surgery. Future, more extensive studies are required before revolutionizing the proximal femoral Multiple Myeloma-related involvement treatment paradigm.

BACKGROUND: Previous studies have shown that surgical technique errors especially the wrong bone tunnel position are the primary reason for the failure of anterior cruciate ligament (ACL) reconstruction. In this study, we aimed to compare the femoral tunnel position and impact on knee function during the ACL reconstruction using measuring combined with fluoroscopy method and bony marker method for femoral tunnel localization.
METHODS: A retrospective cohort study of patients undergoing ACL reconstruction using the bony marker method or measuring combined with fluoroscopy for femoral tunnel localization was conducted between January 2015 and January 2020. A second arthroscopic exploration was performed more than 1 year after surgery. Data regarding patient demographics, the femoral tunnel position, results of the Lysholm score, the International Knee Documentation Committee (IKDC) score, KT-1000 side-to-side difference, pivot shift grade, and Lachman grade of the knee were collected.
RESULTS: A total of 119 patients were included in the final cohort. Of these, 42 cases were in the traditional method group, and 77 cases were in the measuring method group. The good tunnel position rate was 26.2% in the traditional method group and 81.8% in the measuring method group (p < 0.001). At the final follow-up, the Lysholm and IKDC scores were significantly greater in the measuring method group than the traditional method group (IKDC: 84.9 ± 8.4 vs. 79.6 ± 6.4, p = 0.0005; Lysholm: 88.8 ± 6.4 vs. 81.6 ± 6.4, p < 0.001). Lachman and pivot shift grades were significantly greater in the measuring method group (p = 0.01, p = 0008). The results of KT-1000 side-to-side differences were significantly better in the measuring method group compared with those in the traditional method group (p < 0.001).
CONCLUSIONS: The combination of the measuring method and intraoperative fluoroscopy resulted in a concentrated tunnel position on the femoral side, a high rate of functional success, improved knee stability, and a low risk of tunnel deviation. This approach is particularly suitable for surgeons new to ACL reconstructive surgery.

OBJECTIVE: The prevalence of trochlear dysplasia is common in different populations.
BACKGROUND: The prevalence of trochlear dysplasia in the general population, categorised by sex, race, age, and body mass index, has been sparse. This study aimed to define the prevalence of trochlear dysplasia based on the latter categories.
METHODS: Cohort retrospective study.
METHODS: 1162 skeletal mature healthy femora were obtained from a CT-scan-based modelling system (SOMA). Thin slice CT scans were acquired exclusively for medical indications such as polytrauma (20%), CT angiography (70%) and other reasons (i.e. Total Joint Replacement) (10%). Trochlear dysplasia was measured using Pfirmann\'s method. Patient demographics such as age, race and sex were recorded.
RESULTS: The overall prevalence of trochlear dysplasia is 4.5% and is far more common in Asian female patients compared to Caucasian, African and Middle Eastern knees.
CONCLUSIONS: Overall, the prevalence of dysplasia in the general population was determined to be 4.5%, with female patients being more likely to suffer from the condition. Patients of Asian and Caucasian race were more likely to have trochlear dysplasia, while Middle Eastern male patients displayed more dysplastic values than their female counterparts.

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.