Unstable lateral femoral fractures: elements predictable of failure

Objective. Lateral femoral fractures are common events, especially in old frail patients. They can be stable or unstable on the basis of specific features. Optimal treatment requires preoperative evaluation of the fracture pattern and appropriate choice of implant and surgical technique. The aim of this study was to detect variables related to fixation failure in unstable lateral femoral fracture. Methods. We retrospectively evaluated 136 patients treated with intramedullary proximal femur nail (PFN) between January 2016 and December 2017 at our hospital. All fractures were classified according to the AO/OTA classification; the type and length of nail, nail collodiaphyseal angle, type of distal locking and use of steel wire cerclage were recorded. These variables were statistically analysed to evaluate any correlation with the onset of complications, i.e., biological and/or mechanical failure. Results. At the first follow-up at three months, we found 13 failures (9.6%). At 6 months, 38 patients were lost to follow-up and we identified 3 failures as pseudoartrosis. Statistical analysis showed a significant correlation between the type of fracture and failure. No significant differences were detected for the other parameters. Conclusions. When treating a lateral unstable femoral fracture with proximal femoral nail, the only variable significantly related to failure seems to be the fracture pattern. Thorough knowledge of the implant still remains essential to obtain a good result.