Comparative efficacy of the femoral neck system, cannulated cancellous screws combined with medial buttress plate, and cannulated cancellous screws in the treatment of femoral neck fractures in young and middle-aged adults.

This study aimed to evaluate the long-term efficacy of the Femoral Neck System (FNS), cannulated cancellous screws (CCS) combined with a medial buttress plate (MBP), and CCS alone in treating femoral neck fractures in young and middle-aged adults, and to identify independent risk factors for postoperative complications. This retrospective single-center study enrolled 355 patients with femoral neck fractures. The inclusion criteria were patients aged 18-65 years with complete baseline data and a mean follow-up duration of 18.22 ± 6.31 months. Exclusion criteria included pathological/bilateral fractures and significant comorbidities. Based on the surgical technique employed, patients were assigned to the FNS group (n = 165), CCS+MBP group (n = 62), or CCS group (n = 128). Baseline characteristics, surgical parameters, radiographic outcomes (Garden index), complication rates, and functional outcomes were compared among the groups. Statistical analyses included one-way ANOVA, χ² tests, and multivariate logistic regression. Baseline characteristics were comparable across the three groups. Mean fracture healing time was 13.30±1.34 weeks for CCS, 11.42±1.02 weeks for CCS+MBP, and 11.62±1.23 weeks for FNS (P = 0.224). At the 3-month postoperative assessment, the CCS+MBP group demonstrated significantly different functional outcomes compared to both the FNS and CCS groups. Specifically, the Harris Hip Score (HHS) results were 61.43±2.74 for CCS + MBP vs 58.43±2.08 for FNS vs 54.31±2.63 for CCS (P < 0.001); the OHS results were 37.32±2.31 for CCS+MBP vs 43.07±2.92 for FNS vs 42.86±2.90 for CCS (P < 0.001). At 6 months and the final follow-up, no significant differences in HHS or OHS were observed among the groups. Overall complication rates were 16.41% for CCS, 12.90% for CCS+MBP, and 15.15% for FNS (P = 0.819); specifically, femoral neck shortening occurred in 3.91%, 4.84%, and 9.09% (P = 0.171), and osteonecrosis in 7.81%, 4.84%, and 3.64% (P = 0.284), respectively. Multivariate logistic regression identified implant removal (OR=5.56, 95%CI 2.51-12.32, P < 0.001), medial cortex comminution (OR=2.62, 95%CI 1.20-5.73, P = 0.016), Pauwels type III fracture (OR=3.51, 95%CI 1.30-9.50, P = 0.013), and reduction quality Garden index III (OR=2.78, 95%CI 1.98-7.90, P = 0.048) or IV (OR=4.43, 95%CI 1.40-14.00, P = 0.011) as independent risk factors for postoperative complications, whereas Garden index II was protective (OR=0.28, 95%CI 0.10-0.84, P = 0.023). CCS+MBP accelerates early functional recovery but confers no long-term advantage over FNS or CCS, while introducing greater surgical trauma. It is not yet justified to replace FNS or CCS universally. Individualized implant selection and strict control of identified risk factors remain central to optimizing outcomes.