Comparative study on the efficacy of femoral neck system, FNS with anti-rotation screws, and multiple cancellous screws in treating femoral neck fractures in young and middle-aged patients.

Abstract

This study aimed to evaluate and compare the medium- to long-term outcomes of the Femoral Neck System (FNS), FNS combined with the Anti-Rotation Screw (ARS), and Multiple Cancellous Screws (MCS) in the treatment of femoral neck fractures in young and middle-aged patients. A retrospective, multi-group comparative cohort study was conducted on 731 young and middle-aged patients with femoral neck fractures treated at Level I Trauma Center between September 2019 and January 2024. Patients were divided into three groups based on the surgical method: FNS group (327 cases), FNS+ARS group (120 cases), and MCS group (284 cases). Postoperative follow-up assessments included fracture healing time, functional scores (Harris Hip Score [HHS], Oxford Hip Score [OHS], Hip Outcome Score [HOS]), and complication rates (femoral neck shortening, femoral head necrosis, nonunion, and implant-related complications). Key findings demonstrated the FNS+ARS group achieved significantly faster fracture healing (10.21 ± 1.33 weeks) versus FNS (12.52 ± 1.91) and MCS (13.57 ± 2.13 weeks; P = 0.036). Functional outcomes consistently favored FNS+ARS across all timepoints:3 months: HHS (61.54 ± 2.98 vs 58.15 ± 2.34 vs 54.43 ± 2.79, P < 0.001), OHS (37.19 ± 2.35 vs 43.20 ± 2.91 vs 42.89 ± 3.00, P < 0.001), HOS (33.59 ± 2.39 vs 32.21 ± 2.32 vs 30.39 ± 2.72, P < 0.001);6 months: HHS (87.35 ± 5.58 vs 81.95 ± 5.99 vs 76.54 ± 5.45, P < 0.001), OHS (22.66 ± 2.78 vs 25.96 ± 3.64 vs 27.66 ± 4.81, P < 0.001), HOS (76.02 ± 5.47 vs 75.42 ± 7.63 vs 73.38 ± 6.75, P < 0.001);Final follow-up: HHS (91.95 ± 9.06 vs 90.38 ± 11.21 vs 87.67 ± 11.71, P < 0.001), OHS (21.04 ± 8.71 vs 20.41 ± 7.88 vs 23.40 ± 10.18, P < 0.001), HOS (87.51 ± 12.93 vs 85.84 ± 16.22 vs 85.98 ± 15.00, P < 0.001);Complication rates were significantly lower with FNS+ARS, particularly for femoral neck shortening (2.50 % vs 8.87 % vs 5.28 %; P = 0.031) and avascular necrosis (6.67 % vs 10.92 %; P = 0.040). FNS combined with ARS outperformed FNS and MCS in promoting fracture healing, reducing postoperative complication rates, and accelerating functional recovery.