Subtrochanteric Fractures of the Femur

Abstract

The subtrochanteric segment of the femur extends from the lesser trochanter to the junction of the proximal and middle thirds of the diaphysis. This segment of the femur is subjected not only to axial loads of weight bearing, but also to tremendous bending forces because of the eccentric load appli-cation to the femoral head (Fig. 12.1). Recent strain-gauge studies in vivo (Schatzker et al. 1980) have confirmed Pauwel’s and the AO/ASIF contention that the bending forces cause the medial cortex to be loaded in compression and the lateral in tension. Furthermore, they have shown that the compressive stresses in the medial cortex are signif-icantly higher than tensile stresses in the lateral cortex.