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
Alpine ski sports changed rapidly in the last decade. Complex fractures of the proximal tibia, typically seen in high energy trauma, has been seen more frequently and more often related to alpine skiing. The aim of our study was to identify reasons for proximal tibia fracture in alpine skiing and observe the outcome. All patients with proximal tibia fractures related to alpine skiing, which were treated in our two trauma centers were included. The patients received a questionnaire at the emergency department, dealing with accident details and the skiing habits. The fractures were classified according to the AO fracture classification scheme. The follow up was performed at least one year after trauma with the Lysholm, the Tegner activity, as well as the WOMAC VAS Score. Between 2007 and 2010 a total of 188 patients with proximal tibia fractures caused by alpine skiing were treated. 43 patients had a type A, 96 patients a type B and 49 a type C injury. The incidence was increasing over the period continuously. The main trauma mechanism was an accident without a third party involvement with an increased rotational and axial compression impact. All outcome scores were related to fracture severity with significant worse results for the type C fractures. In conclusion, proximal tibia fractures are an increasing and serious injury during alpine skiing. Further technical progress in skiing material should focus on these knee injuries in future.
