Fracture of the femoral neck: identification of the optimal screw position by migration ratio.

Abstract

A consecutive series of fractures of the femoral neck treated with sliding screw and plate osteosynthesis were evaluated radiographically for the optimal position of the screw by use of migration indices. A naturally occurring optimal position of the screw was discovered. It was characterized by four positional indices in the head-neck region which were significantly correlated with minimal migration (or best stability). This optimal screw position gave a better prognostication of reduced risk of early fracture failure compared with the usual sectional division of the femoral head as indicator of screw position.