Risk assessment of femoral head AVN following reduction and fixation of intracapsular hip fractures in patients younger than 65 years over a 10 year follow up

Intracapsular hip fractures in patients under 65 years of age pose unique challenges, requiring optimal treatment strategies to preserve joint anatomy. This study primarily aimed to identify comorbid risk factors contributing to conversion surgery to total hip replacement (THR) due to avascular necrosis (AVN). This single-center, retrospective study included 160 patients (mean age = 50 ± 12 years, 78 males), followed up for an average of 10 years (range: 1–14 years). Fracture classifications were Garden 1 (N = 67), Garden 2 (N = 33), Garden 3 (N = 42), and Garden 4 (N = 19). Surgical procedures included Cannulated Hip Screws (CHS, N = 75), Femoral Neck System (FNS, N = 69), and Dynamic Hip Screw (DHS, N = 17). THR was required for 14 patients (8.7%) due to AVN. The mean age at conversion was 52.76 ± 15 years, with an average time to conversion of 22.2 months (range: 2–132 months). Univariate analysis identified fracture displacement (Garden 3–4), gender, smoking status, and diabetes mellitus as significant predictors for conversion surgery. Surgical method showed a trend toward significance (p = 0.08). A multivariate binary logistic regression model, including fracture displacement, gender, and smoking status as predictors, explained 45% of the variance in conversion to THR (p < 0.01). This study underscores the importance of assessing comorbid risk factors in younger patients with intracapsular femoral neck fractures. Identifying and addressing these factors may enhance the overall management of femoral neck fractures in this population.