Outcomes of Femoral Neck System Procedures in a Major Trauma Centre

Background Femoral neck fractures are common in elderly patients due to osteoporosis and falls. A significant complication is avascular necrosis (AVN), leading to bone tissue death and joint dysfunction. The Femoral Neck System (FNS) was developed to provide minimally invasive fixation with improved rotational and angular stability, aiming to reduce AVN risk; however, clinically significant complications still occur. Hence, this study aimed to assess complication and reoperation rates following femoral neck fracture fixation using FNS in a major trauma centre, and to compare these findings with published outcomes and alternative fixation strategies. Methodology A retrospective review of patients treated with FNS at Sheffield Teaching Hospitals Major Trauma Centre between 2019 and 2024 was conducted. Collected variables included demographics, comorbidities, injury mechanism, time to surgery, fracture displacement, Garden and Pauwels classification, reduction quality, and postoperative outcomes. Reduction quality was evaluated independently by two blinded orthopaedic surgeons using the Garden Alignment Index. Failures were categorised into AVN, mechanical failure, non-union, infection, or re-operation. Results Of the 70 eligible patients, 67 had complete data. The mean age was 73.6 years. The overall complication rate was 22.4%, with 19.4% requiring re-operation. Excluding early postoperative death, these increased to 25.9% and 22.4%, respectively. Reduction was acceptable in 79.1% of cases. Poor reduction was associated with higher complication rates (38.5% vs. 19.0%, p = 0.04). AVN represented 60% of complications, followed by mechanical failure (20%), non-union (13%), and deep infection (7%). Complications were more frequent in patients aged <65 years (43.8%) versus those aged ≥65 years (19.0%). No significant associations were identified with fracture displacement, injury mechanism, gender, or surgical timing. Conclusions Despite its biomechanical advantages, FNS may be associated with higher complication rates, particularly in younger patients and vertically orientated fracture patterns. Vertically aligned fractures (Pauwels III, Garden III-IV) and suboptimal reduction are strong predictors of failure. Further prospective comparative studies are required to better define the role of FNS in femoral neck fracture management.