The bone-brain axis has emerged as a critical framework linking skeletal metabolism to neurodegeneration. Within this axis, bone marrow adipose tissue (BMAT) represents a unique fat depot with distinct endocrine and hematopoietic functions, yet its contribution to Alzheimer's disease (AD) remains unclear. We conducted a two-sample Mendelian randomization (MR) analysis using genome-wide association study (GWAS) summary statistics to assess the causal effects of six fat depots-abdominalsubcutaneous, visceral, spinal, femoral head, total hip, and femoral diaphysis fat-on AD risk. Mediation analysis was further performed to evaluate whether femoral neck bone mineral density (BMD) mediates these associations. Among the six depots, only total hip BMAT showed a significant causal association with AD risk (OR = 1.28, 95% CI: 1.09-1.51, p = 0.003). Total hip BMAT was inversely related to femoral neck BMD (β = -0.43, 95% CI: -0.61 to -0.24, p < 0.001), whereas no causal relationship was detected between BMD and AD (OR = 1.01, 95% CI: 0.89-1.15, p = 0.849), excluding bone loss as a mediator. This study provides the first genetic evidence that excessive hip BMAT increases the risk of AD, supporting the bone-brain axis hypothesis. These findings highlight BMAT as a novel target for understanding and potentially preventing AD.

The aim of this study is to identify possible predilection sites for ligamentous injuries of the knee joint and, based on these findings, provide recommendations to reduce the risk of missed injuries of the knee in cases of ipsilateral femoral shaft fractures. We conducted a systematic review searching the Cochrane, PubMed, and Ovid databases. Inclusion criteria were the modified Coleman methodology score (mCMS) > 50, fully grown patients with mature skeletal development, with ipsilateral femoral shaft fracture and MRI imaging of the knee to assess ligamentous and meniscal injuries objectively. Skeletal immature patients, biomechanical or cadaveric studies, pathological fractures or periprosthetic fractures and animal studies were excluded. We analyzed the data of 636 patients out of 4 manuscripts regarding ligamentous knee injuries with ipsilateral femoral shaft fractures. The collateral ligaments, especially the medial collateral ligament (MCL) is seen with the highest injury rate of 23% (95% CI: 9-41%) followed by the lateral collateral ligament with 10%. The injury-rate was calculated with 9% (95% CI: 4-13%) for the anterior cruciate ligament and 7% (95% CI: 0-19%) for the posterior cruciate ligament. Concomitant ligamentous knee injuries are common in femoral shaft fractures and should be suspected especially in trauma mechanism involving vehicle collisions. Systematic post-stabilization knee examination and with suspected ligamentous injury a timely MRI, with referral to higher-level centers when unavailable, may reduce missed injuries and improve outcomes.

Intramedullary nail deflection correlates to mismatch of a 1.5m vs 1.0m femoral nail bow design: a biomechanical human cadaveric study.

Pediatric femoral fractures are relatively uncommon but represent severe injuries frequently requiring inpatient trauma care. Epidemiological characteristics, fracture patterns, and treatment strategies vary between institutions and regions. This study aimed to analyze the epidemiology, fracture distribution, treatment modalities, complications, and fracture-predisposing comorbidities of pediatric femoral fractures treated at a German level I pediatric trauma center over a 10-year period. All patients aged 0-14 years treated for femoral fractures between January 2012 and December 2021 were retrospectively reviewed. Fractures were categorized using the AO Pediatric Comprehensive Classification of Long-Bone Fractures (PCCF). Demographic variables, fracture characteristics, management approaches, time to consolidation, complications, and relevant comorbidities predisposing to fracture were analysed descriptively in accordance with STROBE recommendations. A total of 183 patients met the inclusion criteria (67.2% male; mean age 5.2 years). Children aged 2-5 years constituted the largest group (42.1%). Femoral shaft fractures were the most frequent femoral fracture type (70%). Surgical management, most frequently elastic stable intramedullary nailing (ESIN), was increasingly utilized with advancing age. The overall complication rate was 14.2%, with the majority classified as minor. Comorbid conditions predisposing to fracture were present in 22% of patients. Femoral shaft fractures represented the predominant femoral fracture type in this trauma-center cohort, particularly affecting boys in early childhood. Surgical stabilization represents an integral component of contemporary pediatric trauma care and was associated with acceptable, predominantly minor complication rates. This study contributes contemporary real-world epidemiological data from a level I pediatric trauma reference center and highlights relevant age-dependent treatment trends and clinical outcomes.

To investigate the reliability of the modified Radiographic Union Scale for Tibial Fractures (mRUST) scores in ballistic lower extremity trauma and to assess the ability of 3-month post-op mRUST in predicting union status at 9-months. Design: Retrospective review. Single Level 1 Trauma Center. Patients that sustained a ballistic femoral (AO/OTA 32) or tibial shaft fracture (AO/OTA 42) aged 18 or over and were treated with intramedullary nailing between 2019 and 2023. Inter- and intra-rater reliability of mRUST score measurements between three fellowship trained orthopaedic trauma surgeons was assessed. The sensitivity and specificity of predicting nonunion at 9-months postoperatively from mRUST 3-months postoperatively was assessed. Inclusion criteria for nonunion analysis required patients to have a 3-month mRUST score as well as a determinable union status. 107 ballistic femoral shaft fractures (203 radiograph sets; 100 male; mean age 31 [18-56]) and 62 ballistic tibial shaft fractures (153 radiograph sets; 51 male; mean age 33 [18-61]) were used to calculate reliability metrics. Inter-rater reliability (Intraclass Correlation Coefficient, ICC) of mRUST in ballistic femoral shaft fractures was 0.64 (95% CI[0.34,0.80]). Intra-rater reliability of mRUST in ballistic femoral shaft fractures was 0.87 (95% CI[0.85,0.89]). Inter-rater reliability of mRUST in ballistic tibial shaft fractures was 0.61 (95% CI[0.43,0.73]) and intra-rater reliability of mRUST in ballistic tibial shaft fractures was 0.81 (95% CI[0.77, 0.84]). In 28 ballistic femoral shaft fractures (24 male; mean age 31 [18-46]), an mRUST-3MO < 8 predicted nonunion in ballistic femoral shaft fractures with a sensitivity of 1.00 and specificity of 0.83. In 25 ballistic tibial shaft fractures (17 males; mean age 34 [18-61]), an mRUST-3MO < 8 predicted nonunion with a sensitivity of 0.71 and specificity of 0.94. This study suggests that the modified Radiographic Union Scale for Tibial Fractures (mRUST) scores possess a lower inter and intra rater reliability in ballistic fractures compared to blunt fractures. They may predict union at 9-months well in ballistic femoral fractures, but only moderately in ballistic tibia fractures. Diagnostic Level III.

After severe hemorrhage and polytrauma, late complications such as multi-organ failure (MOF) remain major contributors to morbidity and mortality. Especially after hemorrhagic shock the kidney is known to be at high risk. As laboratory parameters, like creatinine, provide only delayed and indirect information about kidney function, our study evaluated whether iodine-based spectral computed tomography (SDCT) can quantify renal perfusion in a large-animal polytrauma model. Thirty-two Landrace pigs (70±5kg) were used, randomized into four groups (n=8). Tissue trauma group (TTFx) received a blunt chest injury and bilateral femur shaft fractures. In the shock (HS) group, hemorrhagic shock was induced by controlled blood withdrawal. The polytrauma (PT) group underwent tissue trauma and hemorrhagic shock. Eight uninjured pigs served as controls. Whole-body SDCT with iodine mapping was performed after trauma and after 24 hours. Serum creatinine was measured in parallel. Urine was sampled at baseline, after resuscitation, and after 24 hours. Significant differences in renal perfusion measured by iodine uptake were found during shock and after polytrauma: groups with hemorrhagic shock showed reduced renal perfusion compared with controls (P<0.001). Decreased iodine uptake correlated strongly with increased creatinine levels (ρ=-0.505, P=0.009). Hemorrhagic shock caused pronounced intrarenal functional impairment, reflected by elevated fractional sodium excretion (FENa 2.49% vs. 0.35%, P<0.001), reduced urine osmolality (P<0.001), and decreased urinary urea concentrations (P<0.001). Fractional calcium excretion (FECa), a novel parameter, was strongly increased in the shock group (6.18% vs. 0.19%, P<0.001). After 24-hour resuscitation, no significant differences between the groups were observed in either iodine uptake, creatinine levels, or urinary parameters. Spectral iodine imaging seems to reflect renal perfusion impairment after hemorrhagic shock. The observed correlations with creatinine and urinary parameters suggest that spectral CT may provide a rapid, imaging-based assessment of kidney dysfunction. The renal perfusion normalizes with resuscitation along with renal function parameters. (J Trauma Acute Care Surg. 2026;101: 121-128. c 2026 The Author (s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Surgery of Trauma.). Not applicable.

Osteosarcoma is the most common primary malignant bone tumor, typically affecting adolescents and young adults. While its development is often associated with rapid bone growth and genetic factors, the potential link between metal implants and osteosarcoma remains unclear and rarely reported. This case highlights the unusual occurrence of high-grade osteosarcoma arising at the site of a long-standing metal implant, emphasizing the importance of long-term vigilance in patients with orthopedic hardware. Because implant-associated sarcomas are exceptionally uncommon and causality cannot be inferred from individual cases, detailed clinicopathologic documentation and careful exclusion of alternative etiologies are essential. A 49-year-old White middle eastern male presented with progressive pain and swelling in the right thigh. He had sustained an open right femoral shaft fracture in 1990, treated with open intramedullary nailing using a stainless-steel nail with interlocking screws and cerclage wiring. Intermittent symptoms began in 2013, and he was admitted in 2016 with worsening pain and a presumptive diagnosis of chronic osteomyelitis; empiric antibiotics (vancomycin and meropenem) were initiated. Imaging demonstrated an aggressive osteolytic lesion in the distal femoral diaphysis/metadiaphysis adjacent to the prior fixation site, with cortical destruction and an associated soft-tissue component on magnetic resonance imaging (MRI). Core needle biopsy showed chronic inflammation with atypical stromal proliferation, and subsequent open biopsy confirmed high-grade osteogenic osteosarcoma with fibroblastic and chondroblastic differentiation. Microbiological investigations, including blood cultures and multiple intraoperative tissue cultures, were negative, and histopathology did not support osteomyelitis. The patient received perioperative multi-agent chemotherapy with methotrexate, doxorubicin, and cisplatin (MAP) and underwent hip disarticulation with negative margins. No metastatic disease was detected during 9 years of follow-up, and the patient remains disease-free (Table1). This case adds to the limited literature describing implant-associated osteosarcoma and supports ongoing clinical vigilance for late-onset symptoms around orthopedic hardware. This case illustrates the diagnostic challenge of distinguishing infection from malignancy in patients with late-onset symptoms around orthopedic hardware. While biologically plausible mechanisms such as chronic local inflammation and metal ion exposure have been proposed, this report should be interpreted as an implant-associated presentation rather than proof of implant-induced carcinogenesis. Persistent or progressive pain or swelling near long-standing implants warrants timely imaging and biopsy.

Delayed union and nonunion remain clinically important complications after tibial and femoral shaft fractures. Although traditional risk factors such as smoking and diabetes have been widely investigated, the association between visceral adiposity-related metabolic dysfunction and impaired fracture healing remains unclear. This study aimed to examine the association between the visceral adiposity index (VAI) and delayed union/nonunion after tibial or femoral shaft fractures and to explore whether VAI could improve internally validated prediction models. We conducted a single-center retrospective cohort study of 485 adults who underwent intramedullary fixation for isolated tibial or femoral shaft fractures between January 2022 and June 2025. VAI was calculated using sex-specific equations incorporating waist circumference, body mass index, triglycerides, and high-density lipoprotein cholesterol. The primary endpoint was delayed union/nonunion at 6 months after surgery. The association between VAI and delayed union/nonunion was assessed using multivariable logistic regression and restricted cubic spline analysis. Discriminative performance was compared using receiver operating characteristic analysis, and exploratory machine learning models were evaluated using internal validation. Delayed union/nonunion occurred in 60/485 patients (12.4%). The median VAI was higher in patients with delayed union/nonunion than in those who achieved fracture union [3.1 (IQR, 2.2-4.5) vs. 1.9 (IQR, 1.3-2.8), P < 0.001]. After full adjustment for demographic, lifestyle, metabolic, and fracture-related covariates, each 1-unit increase in VAI was associated with higher odds of delayed union/nonunion (OR 1.61, 95% CI 1.31-1.98; P < 0.001). Restricted cubic spline analysis suggested an approximately linear association, without significant evidence of nonlinearity. VAI showed higher discrimination than body mass index and waist circumference (AUC 0.785 vs. 0.655 and 0.712, respectively). In exploratory internal validation, L1/Elastic Net-regularized logistic regression showed the highest AUC among the evaluated machine learning models (AUC 0.914, 95% CI 0.864-0.963). In this single-center retrospective cohort, higher VAI was associated with an increased risk of delayed union/nonunion after tibial or femoral shaft fractures treated with intramedullary fixation. VAI showed better discrimination than conventional anthropometric measures in internal analyses and may provide additional information for early risk stratification. However, these findings do not establish causality, and external prospective validation is required before clinical implementation.

CLU delays fracture healing and intercepts osteogenic differentiation by enhancing SMURF1-mediated DDX5 ubiquitination.

Patient: Male, 44-year-oldFinal Diagnosis: Left greater trochanteric fracture • right femoral neck fracture nonunion • right femoral neck, intertrochanteric, and upper femoral shaft fracturesSymptoms: Hip pain • muscle weakness • range of motion limitation • walking difficultiesClinical Procedure: PRP injections • ultrasonographySpecialty: Orthopedics and Traumatology • RehabilitationObjective: Unusual or unexpected effect of treatmentBackgroundFemoral neck fractures are prone to nonunion due to compromised vascular supply. While surgical revision remains the standard of care, biological approaches such as platelet-rich plasma (PRP), a concentrate rich in growth factors that enhance bone healing, offer a less invasive option. This report describes the case of a 44-year-old man, who worked as a manual laborer, with a femoral neck fracture nonunion who refused further surgery and was treated with ultrasound-guided percutaneous injections of PRP.Case ReportNine months after undergoing internal fixation for a complex hip fracture, a 44-year-old man presented with persistent right hip pain and gait impairment. Radiographic evaluation confirmed the diagnosis of an oligotrophic nonunion of the femoral neck. The patient declined surgical revision, and a nonsurgical biological intervention was pursued. This consisted of 3 ultrasound-guided percutaneous injections of autologous PRP administered at 1- to 2-week intervals, followed by a structured, phased rehabilitation protocol. Over the ensuing 7 months, serial radiographic follow-up demonstrated progressive bony union. The treatment resulted in complete resolution of pain at rest, minimal pain on weight-bearing, and a successful return to unassisted walking and light work. No adverse events were reported.ConclusionsThis case demonstrates that a series of ultrasound-guided percutaneous PRP injections can serve as a successful, minimally invasive, non-surgical alternative for promoting union in selected cases of femoral neck nonunion, potentially allowing patients to avoid revision surgery.

Background and purposeThere is no universal consensus on evaluating the quality of pediatric fracture care. While U.S. News ranks hospitals based on surgical timing and procedural benchmarks, additional metrics such as complication rates, reoperations, and patient-reported outcomes could provide a more comprehensive assessment. We aimed to evaluate pediatric fracture care outcomes at a Level I trauma center, emphasizing standardization and transparency in benchmarking.MethodsThis retrospective study reviewed all fractures diagnosed at HUS New Children’s Hospital, Helsinki from 2018 to 2022. U.S. News criteria were applied to completely dorsally displaced supracondylar humerus (Gartland III) fractures, femoral shaft fractures, and displaced forearm fractures to evaluate timeliness, method of treatment, and anesthesia use. The modified Clavien–Dindo–Sink system was used in complex fractures. Permanent iatrogenic nerve injuries and deep infections were registered in all fractures.Results10,144 fractures were diagnosed, of which 18% were treated in the operative room. Surgery started within 18 h in 173 (87%) of Gartland III and 108 (79%) of femoral shaft fractures. Open reduction rate was 24% in Gartland III fractures. Most (60%) displaced forearm fractures were managed without general anesthesia. The overall complication rate for Gartland III and femoral shaft fractures was 13%; unplanned return to surgery occurred in 2.2% respectively. Permanent iatrogenic nerve injuries and deep infections were rare (0.04% and 0.3%) in all fractures.ConclusionSurgical treatment of supracondylar humerus and femoral shaft fractures in children was performed safely and effectively at our institution. The majority of pediatric forearm fractures were managed in the emergency department without anesthesia. The incidence of iatrogenic nerve injuries and postoperative infections was very low. Incorporating broader metrics such as complications, outcomes, and satisfaction would offer a more complete assessment of care quality.

BACKGROUND Management of infected segmental defects of the femoral diaphysis is challenging because infection control, restoration of stability, and reconstruction of bone loss must all be achieved. The induced membrane technique, also known as the Masquelet technique, is a 2-stage reconstructive method for large post-infectious bone defects. This report describes reconstruction of an 11-cm femoral diaphyseal defect secondary to chronic osteomyelitis in a 14-year-old girl. CASE REPORT A 14-year-old girl sustained a Gustilo-Anderson type II open fracture of the right femoral shaft after a motor vehicle accident and initially underwent debridement and external fixation. During follow-up, pin-site infection developed, and infected nonunion with chronic osteomyelitis was diagnosed 6 months after injury. At the first stage, the external fixator was removed, radical debridement and sequestrectomy were performed, and an 11-cm segment of necrotic femoral diaphysis was resected until punctate cortical bleeding ("paprika sign") was observed. A vancomycin-loaded polymethylmethacrylate cement spacer was placed around a locked intramedullary nail. Nearly 3 months later, second-stage reconstruction was performed, with removal of the spacer, repeat intramedullary fixation, and autologous bone grafting using a reamer-irrigator-aspirator system combined with iliac cancellous bone. At 6 months after the second-stage procedure, the patient was fully weight-bearing, had resumed normal daily activities, and showed radiographic bone healing without recurrent infection. CONCLUSIONS The induced membrane technique may be an effective option for staged reconstruction of a large post-infectious femoral diaphyseal defect in an adolescent when thorough debridement, stable fixation, and adequate autologous bone grafting are achieved.

Background and purpose2-dimensional radiographs may underestimate 3-dimensional fracture displacement. CT-based micromotion analysis (CTMA) enables precise quantification of interfragmentary movement in 3 dimensions. We aimed to evaluate CTMA for quantifying fracture displacement, surgical reduction, and postoperative fragment movement in trochanteric hip fractures, and assessed measurement agreement from repeated follow-up scans.MethodsWe conducted a prospective cohort study including 15 patients with trochanteric fractures treated with a cephalomedullary nail at Uppsala University Hospital between 2020 and 2023. Each patient underwent CT imaging preoperatively, postoperatively, and at follow-up. Measurement agreement was assessed using 2 follow-up CT scans acquired after patient repositioning, when the fractures were healed. The femoral shaft (or nail) served as the fixed reference, and the femoral head (or spiral blade) was analyzed relative to the mirrored contralateral hip to quantify fracture displacement. Fracture movement during healing was assessed by comparing postoperative and follow-up scans.Results12 patients had complete imaging. Measurement agreement between repeated CTMA scans showed sub-millimetric repeatability for translation and < 1° for rotation. Mean initial fracture displacement relative to the mirrored contralateral hip was 55.6° in total rotation and 48.4 mm in total translation, improving postoperatively to 17.5° and 15.9 mm, and remaining essentially stable at follow-up. Between the postoperative and follow-up scans, total movement of the femoral head averaged 5.4° (95% confidence interval [CI] 2.8–8.1) and 6.4 mm (CI 3.9–8.9). Spiral blade total translation averaged 5.4 mm (CI 3.0–7.9). Observed movement followed expected directions, with predominant femoral shortening (z-translation −4.4 mm), medialization (x-translation −3.3 mm), and slight external rotation (z-rotation +2.4°) of the femoral shaft.ConclusionCTMA demonstrated good measurement agreement and repeatability for quantifying fracture displacement, surgical reduction, and postoperative fragment movement in trochanteric fractures.

Stress fractures affect military personnel at higher rates than the general population. They can lead to serious injury and negatively impact military force readiness. Most prior studies have focused on recruits undergoing basic training. Our goal was to characterize stress fractures over the full spectrum of military career stages to identify whether fracture locations varied by career length. A retrospective chart review was conducted of a 3-year period (January 1, 2017-December 31, 2019) to identify active duty military patients in the National Capital Region diagnosed with a new stress fracture. Patients were stratified by career length: New Recruit (<12 months of service), Early-Career (1-5 years of service), Mid-Career (5-14 years of service), and Late-Career (>14 years of service). The percentage of fractures at each anatomic location was reported and compared by binary career length (New Recruit vs. others) with Chi-square or Fisher's exact tests performed among the full cohort. The total cohort was stratified by sex, and the analysis was repeated separately in males and females. The percentage of patients who presented with multiple fractures was similarly reported and compared by career length, among the full cohort and by sex strata. The study was approved by the Walter Reed National Military Medical Center Institutional Review Board, protocol # WRNMMC-2018-0162. The study population included 446 military members with 537 total fractures. Percentages of femoral neck (11.1% vs. 3.6%, P = .001), femoral shaft (8.1% vs. 1.8%, P = .001) and pelvis fractures (3.8% vs. 0.7%, P = .031) were greater in the New Recruit group compared to the other career-length groups. Percentage of foot fractures was lower (19.2% vs. 34.3%, P < .001) in the New Recruit group vs. the other career-length groups. Percentage of patients presenting with multiple stress fractures (23.7% vs. 10.1%, P < .001) was greater in the New Recruit group vs. the other career-length groups. The significant differences in femoral shaft and foot fractures persisted when males and females were analyzed separately. Our findings support that the distribution of the anatomic locations of stress fractures differs between military members in the New Recruit period versus later in their careers. Specifically, New Recruits had a higher percentage of femoral neck, femoral shaft, and pelvic fractures. Providers may consider having a lower threshold for imaging new recruits with hip pain as this could identify a stress reaction before it becomes a stress fracture. Potential explanations for the findings include sex, training intensity, and force attrition. Some of the significant findings persisted when males and females were analyzed separately, which supports that there are contributions from other factors than patient's sex. Additional studies are needed to build upon these findings. Limitations included the use of ICD-10 codes and physician reporting to identify stress fractures, the lower numbers of patients once the total study population was stratified by sex, unavailability of bone density data, and unclear generalizability of the findings.

Arciero Technique for Anatomic Posterolateral Corner Reconstruction of Knee Following Femoral Nailing: A Current Technique.

Pediatric femur fractures are treated with rigid intramedullary nails, flexible intramedullary nails, and plates, which are usually removed after fracture union. This study aimed to analyze complications, estimated blood loss (EBL), length of stay, and operative times for implant removal after successful surgical management of pediatric diaphyseal femur fractures. After IRB approval was received, data were collected from pediatric patients at a major level I trauma center from 2008 to 2023. Fixation types were separated based on flexible nail, rigid nail, and plating. Postoperative complications included wound dehiscence, wound abscess, infection, and hematoma. Admission rates were higher for the rigid nail group than for the flexible nail group. No difference was found for admission rates between the plate and nail groups. In terms of OR time, plates were the longest at 63 minutes on average, rigid nails at 58 minutes, and flexible nails at 36 minutes. EBL was greater for plate removal than for all nail removal, and greater for rigid nail removal than for flexible nail removal. Bony overgrowth was on the implant in 17 nail and 8 plate patients. It was statistically higher in the rigid nail group compared with the flexible nail group. Time between fixation and removal was greater for the nail group than the plate group. When comparing flex nails to rigid nails regarding time to removal, this remained significant (9.4 and 12.4mo, respectively; P<0.0001). There was one incidence of refracture, which occurred in the flexible nail group. Operative time and EBL were higher for plate-removal patients. Bony overgrowth and time between fixation and removal were significantly higher for the nail group. Eleven intraoperative complications and 8 postoperative complications were documented for the nail-removal patients; none were documented intraoperatively or postoperatively for the plate-removal patients. Refracture in the short-term follow-up period was very low. Implant removal following pediatric femur fractures has a low complication rate, with greater operative time and EBL for plates. Level III.

AimsSegmental bone defects of the femur and tibia present a major challenge for reconstructive surgery, especially in joint-sparing oncological and post-traumatic cases. Patient-specific implants (PSIs), enabled by 3D imaging and additive manufacturing, offer tailored solutions. This review aimed to systematically evaluate clinical applications of PSIs for femoral and tibial shaft reconstruction in terms of mechanical survival rate, and introduce a classification framework to guide implant design and fixation, as well as communication.MethodsA systematic search of PubMed and Embase identified studies reporting joint-sparing reconstructions using PSIs for segmental femoral or tibial defects. Data were extracted on implant design, fixation method, material, biological augmentation, and clinical outcomes. A novel classification system was developed to categorize implants by defect location (unicortical, diaphyseal, meta-extended) and fixation type (screws, plates, nails, stems, hybrid). Kaplan-Meier survival analysis was used to assess five-year implant survival across subgroups.ResultsA total of 53 studies involving 299 patients were included. Titanium was the predominant material, often featuring lattice structures to support bone ingrowth or grafting. Fixation methods varied, with hybrid fixation showing the highest five-year implant survival rate (97%), followed by stems (95%) and plate- or nail-only fixation (each 90%). Most implants remained failure-free at final follow-up; structural failure was the most common complication. The classification system enabled structured comparison across implant types. A notable concentration of studies (27/53) originated from China, suggesting regional leadership in PSI innovation, potentially linked to regulatory flexibility compared to the European Union.ConclusionThis review provides a structured overview of PSI design and fixation, and outcomes for joint-sparing femoral and tibial reconstruction. The proposed classification framework facilitates standardized reporting and interdisciplinary communication. Hybrid fixation methods demonstrated superior mechanical survival, supporting their use in future PSI designs.Cite this article: Bone Joint Res 2026;15(6):647–661.

Closed reduction and intramedullary nail (IMN) fixation remains the gold-standard treatment for femoral shaft fractures (FSFs). However, technical challenges persist in achieving and maintaining anatomical alignment during the closed reduction process. This study aimed to evaluate the clinical efficacy of Hexapod external fixator (HEF)-assisted closed reduction and IMN fixation in the management of FSFs. A retrospective cohort study was conducted on 25 patients undergoing closed reduction and IMN fixation with eccentric HEF assistance between June 2021 and January 2023. Operative parameters, including operative duration, blood loss, fluoroscopy frequency, reduction time, radiographic union time, and complication rates, were systematically recorded. Functional outcomes were evaluated at the final follow-up using the Liu et al. criteria, a validated scoring system for FSFs rehabilitation. All 25 patients underwent postoperative follow-up for 18-24 months (mean: 23.5 months). Closed reduction was achieved in all cases without requiring conversion to open reduction. The final radiographic evaluation confirmed radiographic union at the fracture site in all patients. A single case (4%) of delayed union (defined as incomplete bridging callus at 6 months) was managed by transitioning from static to dynamic interlocking screw fixation, achieving radiographic union at 9 months postoperatively. No instances of neurovascular injury, implant failure, deep infection, or nonunion were observed. The mean operative duration was 76.5min (range: 46-102), with an average blood loss of 110.0 mL (range: 60-180). Fluoroscopy frequency averaged 8.4 exposures (range: 4-17), while reduction time and radiographic union averaged 9.5min (range: 7-13) and 5.9 months (range: 3-9), respectively. According to the Liu et al. criteria, 21 cases (84%) achieved excellent outcomes and 4 (16%) were graded as good, resulting in a 100% excellent-to-good rate. The use of eccentric Hexapod external fixator assisted closed reduction and intramedullary nail fixation for the treatment of FSFs offers a reliable solution. Its ability to minimize soft tissue damage, reduce radiation exposure, and achieve high union rates positions it as a promising alternative to existing technologies.

Bone strength is influenced by the stiffness and spatial distribution of mineralized tissue. Bone mineral density (BMD) is used to assess osteoporosis but is limited in evaluating microarchitectural and geometric changes. We investigated Trabecular Bone Score (TBS), BMD, and hip structural analysis (HSA) in celiac disease (CD) patients. A cross-sectional study compared bone density factors in CD patients with a healthy control group matched for gender, BMI, and age. Dual-energy X-ray absorptiometry (DXA) assessed BMD at the femoral neck, hip, and lumbar spine (L1-L4). TBS was measured at the lumbar spine, and HSA evaluated geometry at the narrow neck (NN), femoral shaft (FS), and intertrochanteric (IT) regions. The study included 73 CD patients and 93 healthy controls. The prevalence of low BMD for age at the lumbar spine, total hip, femoral neck, and at any skeletal site was significantly higher in the CD group compared with controls (P < 0.05). No significant differences were found in TBS between groups (P > 0.05). IT buckling ratio (BR), FS BR, and FS endocortical diameter were significantly higher in the CD group, while IT cortical thickness, FS cross-sectional area, and FS cortical thickness were significantly higher in controls (P < 0.05). Patients with celiac disease demonstrated adverse DXA-derived structural and densitometric skeletal parameters, which may potentially contribute to increased skeletal fragility, highlighting the importance of assessing both BMD and structural factors.

Prediction of femoral shaft fracture healing and clinical decision support through integration of mechano-biological modeling and machine learning.