Biomechanical aspects of the repair of intertrochanteric fractures.

A two-dimensional model of a repaired intertrochanteric fracture has been proposed in order to estimate the forces transmitted by a sliding screw implant and at the fracture site. These forces have been estimated from the radiographs of 55 repairs which were previously graded as satisfactory or unsatisfactory. The unsuccessful group was found to have significantly higher fracture angles as well as increased forces and moments transmitted by the implant. The results support the view that increased loading of implant and therefore high stresses in the surrounding cancellous bone contribute to the failure of repairs.