Evaluation of the Risk Factors for Mechanical Failure of Intertrochanteric Femoral Fracture Treated with Intramedullary Nailing

Aim: The aim of this study was to evaluate the radiological and clinical risk factors predisposing the proximal lag screw to mechanical failure in patients with pertrochanteric femur fractures treated with intramedullary nailing. Material and Methods: All intertrochanteric fracture cases were evaluated retrospectively and 298 patients (24 had mechanical failure) were included in this study. The patients were compared in terms of demographic data, Singh index, reduction quality according to the Baumgaertner scale, proximal lag screw position according to Cleveland-Bosworth quadrants and the Parker ratio, and the calcar femorale restoration and tip-apex distance. Results: There was no statistically significant difference in terms of gender (p=0.745), age (p=0.848), American Society of Anesthesiology scores (p=0.725), body mass index (p=0.648) and Singh index (p=0.119) between the two groups. There were statistically significant differences between the two groups in terms of the following variables; number of patients with unstable fracture (p<0.001), poor reduction quality (p<0.001), calcar femorale discontinuity (p<0.001), center-center/center-inferior lag screw position (p<0.001), and Parker ratio on the lateral view (p=0.002). The center-center/center-inferior lag screw position, good reduction quality and calcar femorale restoration were found to be parameters predicting superior outcomes according to logistic regression analyses. Conclusion: From the results of this study, it was concluded that although the preoperative reduction of the fracture and tip-apex distance are mandatory to prevent failure of the proximal lag screw, posteromedial discontinuity and lag screw position have a vital role in the treatment of interochanteric femur fracture fixed with intramedullary nailing.