Proximal Femoral Nail Mechanical Failure: A Case Report and Biomechanical Study.

Intramedullary nailing is an established method for treating pertrochanteric fractures. However, the widespread use of this technique comes along with a variety of complications. We present a case of a 50-year-old female who presented to the emergency department suffering a left pertrochanteric fracture. She was treated with proximal femoral nailing and discharged home. Nine months later, she presented again to the emergency department with pain and an inability to bear weight. Imaging revealed the mechanical failure of the hip screw and loss of fracture fixation. Revision surgery included extraction of the broken hardware and a left hip hemiarthroplasty. The removed implant was sent for further evaluation. Fractographic analysis showed acute breakage due to bending and torsion forces acting on the screw with no relevant signs of metal fatigue. This biomechanical method is of great value for the surgeon and the implant manufacturer in order to understand the failure pattern and optimize future implants and fixation techniques. Improved implant biomechanical properties together with meticulous surgical technique constitute the cornerstones for optimal results.