Predictors Of Failure In Reverse Obliquity Intertrochanteric Fractures Treated With Cephalomedullary Nails

Background: Reverse obliquity intertrochanteric (IT) fractures (AO/OTA 31-A3) are inherently unstable injuries with substantially higher rates of implant failure compared to standard obliquity fractures. Despite the widespread adoption of cephalomedullary nails (CMNs) as the preferred fixation device for these fractures, the radiological and surgical predictors of failure specific to AO/OTA 31-A3 fractures remain incompletely characterized. Objective of this study is to identify preoperative and postoperative predictive factors of implant failure in AO/OTA 31-A3 intertrochanteric fractures treated with cephalomedullary nails. Methods: A retrospective study of 45 patients with AO/OTA 31-A3 fractures managed with cephalomedullary nails at the Department of Orthopaedics, Saveetha Medical College and Hospital, Chennai, from October 2023 to September 2025 was conducted. Postoperative radiographs were assessed for reduction quality, posteromedial cortical support, tip-apex distance (TAD), and neck shaft angle (NSA). Univariate and multivariate logistic regression were used to identify independent predictors of implant failure. Results: Implant failure occurred in 6 patients (13.3%), comprising 3 cases of helical blade perforation, 2 cases of nail breakage, and 1 case of helical blade cutout. Multivariate logistic regression identified poor reduction quality (OR 28.70; 95% CI 1.91–431.88; p = 0.015) and loss of posteromedial support (OR 18.98; 95% CI 1.40–257.08; p = 0.027) as independent predictors of implant failure. Tip-apex distance and neck shaft angle did not reach statistical significance on multivariate analysis. Conclusion :Poor fracture reduction quality and loss of posteromedial cortical support are the most significant independent predictors of implant failure in reverse obliquity intertrochanteric fractures treated with cephalomedullary nails. Achieving and maintaining anatomical or near-anatomical reduction with preserved posteromedial cortical contact is essential for minimizing fixation failure in this challenging fracture pattern.