The impact of subsidence on hip function: A comparative study between Proximal Femoral Nail Anti-rotation-2 and Halifax Femoral Nail in unstable trochanteric fractures

Abstract

Background: Unstable trochanteric fractures pose a significant challenge in orthopedic surgery, particularly in elderly patients with poor bone quality. Achieving biomechanical stability while minimizing complications requires careful consideration of intramedullary nail design. This study aims to compare two commonly used implants – Proximal Femoral Nail Anti-rotation-2 (PFNA-2) and Halifax Femoral Nail – by evaluating their clinical, radiological, and functional outcomes, with a focus on surgical efficacy, complications, and functional recovery. Methods: A prospective, randomized clinical trial involving 60 elderly patients with AO/OTA 31A2 or 31A3 unstable trochanteric fractures was conducted over 1 year. Patients aged 60–80 years were randomized into two equal groups (n = 30 each) to receive either PFNA-2 or Halifax Nail fixation. Primary outcomes were evaluated using the Harris Hip Score (HHS) at 6 and 12 months postoperatively. Secondary outcome measures included neck-shaft angle, tip-apex distance, and screw positioning according to the Cleveland Index. Operative parameters, including surgical time, blood loss, and complications, were systematically recorded and analyzed. Results: Both implants demonstrated comparable efficacy regarding operative time (Halifax: 31.7 ± 5.5 vs. PFNA-2: 33.0 ± 7.9 min, p = 0.45) and intraoperative blood loss (Halifax: 89.5 ± 12.6 vs.PFNA-2: 97.7 ± 22.9 ml, p = 0.09). Halifax Nail achieved significantly superior screw positioning with 76.7% optimal center–center placement compared to 43.3% in the PFNA-2 group (p = 0.008). Subsidence was absent in the Halifax group but occurred in 6.7% of PFNA-2 cases. HHSs improved progressively in both groups, with Halifax showing marginally higher scores at 6 months (83.6 ± 4.3 vs.81.5 ± 6.4) and 12 months (87.4 ± 3.9 vs.85.8 ± 5.6), though differences were not statistically significant. Discussion: Both PFNA-2 and Halifax Nails are effective for managing unstable trochanteric fractures. The Halifax Nail’s innovative tri-wire technology™ offers superior rotational stability, optimal screw positioning, and demonstrates a trend towards reduced subsidence, making it particularly advantageous for patients with compromised bone quality. These findings support individualized implant selection based on patient factors and bone quality assessment.