The proximal geometry and design of trochanteric nails affects initial construct stiffness, fatigue survival, and preservation of biomechanical stability over time. Eight pairs of human cadaveric femora were implanted with two different short intramedullary nails with (Intertan, (S&N)) and without (Gamma 3, (Stryker)) interlocking lag screws. Femoral osteotomies were performed to generate a pertrochanteric multifragmentary unstable fracture (OTA 31-A 2.2). The bones were tested in a cyclic testing protocol with increasing loads of 100 N every 20.000 cycles (start point 50/500 N) simulating one leg stance. The position of the femur was 10° adduction and 10° extension. Stiffness, failure load, and cycles to failure were measured.Hypothesis
Materials & Methods