Do trabeculae of femoral head represent a structural optimum?

This paper presents a numerical investigation in the influence of loading on the trabecular architecture of a femoral head using structural optimization. Previous literature has shown that structural optimization can be used to simulate the response of bone to external loading conditions, in the cases of os-calcis and vertebrae of which the loading conditions may be considered relatively simple. The geometry of a typical femoral head is modeled in the two-dimensional finite element environment with 8-noded quadrilateral elements. Three load cases were considered: 1) the single leg stance phase of gait; 2) the extreme of abduction experienced on a daily basis; 3) the extreme of adduction experienced on a daily basis. These were chosen to give an insight into the influence of difference loading conditions on various architectural features of the femoral head. The results obtained from structural optimization applied to investigate the effects of frequency of load cases suggests that the frequency of load cases is not directly proportional to their influence on the trabecular architecture. The paper also presents some preliminary results, using the same technique, of the influence of a prosthetic femoral stem on the architecture of the surrounding trabecular bone.