Association of Surgical Approach with Intraoperative Femoral Fracture Patterns During Cementless Hemiarthroplasty for Femoral Neck Fracture

Abstract

Background/Objective: Intraoperative femoral fractures during cementless hemiarthroplasty may present with distinct anatomical patterns. We examined whether surgical approach was associated with greater trochanteric versus stem-stable periprosthetic fracture patterns in older patients with osteoporotic-type femoral morphology; stem geometry was evaluated as an additional implant-related factor. Methods: We retrospectively reviewed 292 patients aged ≥75 years who underwent cementless bipolar hemiarthroplasty for low-energy displaced femoral neck fractures at a tertiary referral trauma center between January 2019 and July 2023. Patients were grouped according to stem geometry (fit-and-fill or tapered-wedge) and surgical approach (lateral or posterior). Associations were assessed using multivariable logistic regression, Firth-penalized regression, and stabilized inverse probability of treatment weighting (IPTW). Results: Intraoperative fractures occurred more frequently with the lateral approach than with the posterior approach (23.7% vs. 12.2%; p = 0.015), primarily because of greater trochanteric fractures (9.5% vs. 2.4%; p = 0.016). Periprosthetic fracture rates did not differ significantly between the approaches (14.2% vs. 9.8%; p = 0.284). In the Firth model, the posterior approach was associated with lower odds of greater trochanteric fracture (OR 0.25, 95% CI 0.08–0.80; p = 0.019); after IPTW, the corresponding estimate was OR 0.19 (95% CI 0.05–0.76; p = 0.019). Conclusions: The surgical approach was primarily associated with greater trochanteric fractures, whereas no independent association was observed with stem geometry. Pattern-specific analysis may provide a clearer characterization of intraoperative fracture associations in this setting.