特発性大腿骨頭壊死症

PURPOSE: Curved intertrochanteric varus osteotomy (CVO) is a joint-preserving procedure for osteonecrosis of the femoral head (ONFH). Computer-assisted navigation may improve osteotomy accuracy, but its clinical benefit remains uncertain. This study aimed to evaluate the clinical outcomes of navigation-assisted versus conventional CVO. METHODS: We retrospectively reviewed 58 patients (62 hips) who underwent CVO for nontraumatic ONFH during 2010-2023. Conventional CVO was performed in 2010-2018 (group C), whereas navigation-assisted CVO was performed since 2019 (group N). Clinical outcomes included operative time, blood loss, complications, Harris Hip Score (HHS), leg length discrepancy (LLD), and conversion to total hip arthroplasty (THA). Radiographic outcomes included intact ratio, collapse progression (> 3 mm), leg shortening, and femoral lateralisation. Outcomes were compared, and survivorship was evaluated using Kaplan-Meier analysis. RESULTS: The HHS at one year postoperatively was higher in group N (87.6 ± 10.8) than in group C (81.1 ± 14.1; p = 0.048); no difference was observed at final follow-up. No significant between-group differences were observed in the postoperative intact ratio, collapse progression, or conversion to THA. However, leg shortening from preoperatively to bone union was smaller in group N than in group C (7.0 ± 5.0 vs. 11.9 ± 6.2 mm, p = 0.001), and subjective LLD was less frequent (group N: 10.0% vs. group C: 34.4%, p = 0.033). CONCLUSION: Navigation-assisted CVO did not improve joint-preserving outcomes, including collapse progression or conversion to THA. Nonetheless, postoperative leg shortening and subjective LLD were significantly reduced, which may support better early postoperative hip function.

OBJECTIVES: The purpose of this study is to propose a new classification of osteonecrosis of the femoral head (ONFH) based on the relationship between the epiphyseal line and osteonecrotic boundary, to offer a reference for prognostic assessment of ONFH and provide strategic guidance for hip surgical interventions. MATERIALS AND METHODS: This retrospective, single-center study commenced by gathering data on patients diagnosed with ONFH between June 2018 and May 2023. Patients were classified into five types based on the relationship between the epiphyseal line and the osteonecrotic boundary on magnetic resonance imaging coronal midsections. Various imaging findings, including bone marrow edema, cystic lesions, microfractures, collapse, and crescent signs, were assessed. Statistical analyses were performed to determine the association between this relationship and disease progression. RESULTS: We researched 289 ONFH patients (42.53 years ± 13.66, 193 men) (405 hips) who met our selection criteria. Type A comprised 35.31 %, Type B 56.54 %, and Type C 8.15 %. Significant differences were observed among Types A, B, and C concerning the presence of cystic lesions, microfractures, collapse, and crescent signs (p < 0.001). Univariate logistic regression analysis demonstrates a progressive increase in structural impairment risks across classifications. Additionally, significant differences were also found in the subtypes of Type B (B1, B2, B3). CONCLUSION: The relationship between the epiphyseal line and the osteonecrotic boundary is closely associated with the progression of ONFH, particularly in the development of femoral head collapse. This study introduced a novel imaging classification system for ONFH, providing valuable insights for clinical management.

➢ Nontraumatic osteonecrosis of the femoral head should be suspected in patients who are <50 years of age who have persistent hip pain despite normal radiographs.➢ Bilateral involvement is common; magnetic resonance imaging (MRI) of the contralateral hip is recommended.➢ MRI is the most sensitive modality for detecting early disease.➢ Femoral head sphericity is assessed on anteroposterior, lateral, and 30º view radiographs.➢ Small pre-collapse lesions have the best prognosis. Large lateral lesions and subchondral collapse predict rapid progression.➢ Systemic risk factors and multifocal disease should be actively evaluated.➢ Joint-preserving procedures are most effective before structural collapse.➢ Total hip arthroplasty remains the most reliable treatment after femoral head collapse.

Steroid-induced osteonecrosis of the femoral head (SONFH) is a crippling orthopedic disease. While glucocorticoids are a well-established etiological factor, the molecular framework driving the cascading tissue destruction remains elusive. Endoplasmic reticulum stress (ERS) has emerged as a central pathogenic hub. This review comprehensively synthesizes current evidence on how ERS orchestrates the multi-dimensional pathological network in SONFH, focusing on specific signaling paradoxes and translational barriers. Mechanistically, ERS drives irreversible osteoblast apoptosis via the PERK-CHOP axis and impairs endothelial regeneration by suppressing mTOR signaling. Notably, ERS exhibits profound microenvironmental heterogeneity: in articular chondrocytes, it aberrantly stabilizes HIF-1α to precipitate matrix degradation-a stark contrast to its canonical vasculoprotective role. Furthermore, ERS exacerbates intraosseous ischemia through a positive feedback loop with lipid metabolism. Importantly, we identify the "ischemic island" effect (a physical sclerotic barrier) and inherent biomechanical discrepancies in quadrupedal animal models as primary bottlenecks hindering the clinical translation of potent ERS inhibitors. To bridge this translational chasm, we propose combinatorial interventions coupling ERS modulators with advanced bone-targeted delivery systems (e.g., Asp8-modified nanocarriers) to breach the ischemic barrier, offering a pivotal strategy for future precision joint-preserving therapies.

BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is idiopathic osteonecrosis of the femoral head. The effects of proximal femoral varus osteotomy (PFVO) on femoral head revascularization are unknown. We evaluated whether patients with early-stage LCPD treated with PFVO had a higher revascularization rate than those receiving nonoperative treatment with serial perfusion magnetic resonance imaging (pMRI). METHODS: Forty-nine patients (49 hips) in early-stage LCPD with ≥2 pMRIs treated nonoperatively (n = 22) or with PFVO (n = 27) were retrospectively analyzed. The mean age of diagnosis was 8.2 ± 1.7 years (range: 5.3-12.2), median pMRI of 3 (IQR:2-4; range: 2-6), and Waldenström stage I (n = 37) or IIa (n = 12). The revascularization rate (%/month) was assessed in 4-month intervals. Time to Waldenström stage IIIb and full weight-bearing status (FWB) were compared. RESULTS: Baseline characteristics (age, initial perfusion, Waldenström stage) were similar between groups. Perfusion was higher in the PFVO group at 4 to 8 (56 ± 20 vs. 80 ± 12%, p = 0.001) and 12 to 16 months (68 ± 25 vs. 91 ± 7%, p = 0.02) follow-ups. The PFVO group had significantly higher revascularization rates at 3 intervals: 4 to 8 (4.2 ± 2.7 vs. 7.0 ± 2.1%/month, p = 0.006), 8 to 12 (3.4 ± 1.7 vs. 6.1 ± 1.5%/month, p = 0.004), and 12 to 16 months (2.5 ± 1.3 vs. 4.9 ± 1.1%/month, p = 0.002). The PFVO group had a shorter time to Waldenström stage IIIb (22.7 ± 8.7 vs. 17.1 ± 6.9 months, p = 0.02) and was associated with earlier FWB (18.8 ± 6.5 vs. 13.1 ± 4.7 months, p = 0.008). CONCLUSIONS: The PFVO group had faster revascularization and a shorter time to the late-reossification stage. SIGNIFICANCE: This study is the first to investigate the effects of PFVO on revascularization rate using serial pMRI. These findings provide novel insight into the biologic effect of PFVO on femoral head revascularization. LEVEL OF EVIDENCE: Level IV, therapeutic. See Instructions for Authors for a complete description of levels of evidence.