Abstract

In this study we assess the clinical and radiological outcomes after surgical fixation of unstable, extra-capsular fractures of the proximal femur using two designs of short intramedullary nail. We reviewed 158 patients of which 131 had fixation using the Intra Medullary Hip Screw (IMHS original Richards Compression Hip Screw design) and 27 with the original design Proximal Femoral Nail (PFN Synthes). Outcome measures including non-union, peri-implant fracture, post-operative function and mortality were similar between groups. Proximal screw cut-out and consequently re-operation rate were significantly higher for the PFN. A number of variables may predispose a patient to develop screw cut-out including gender, experience of surgeon, fracture pattern, implant design and tip-apex distance. As such a multivariable logistic regression model was used to investigate the independent effects of these variables on proximal screw cut-out. Only tip-apex distance was found to have a significant association with proximal screw cut-out and differences between implant designs could be accounted for by surgical technique rather than implant design. The results of this study suggest that both implants have similar post-operative outcome measures and complication rates when implanted correctly.