Finite element modeling to aid in refining the rehabilitation of amputees using osseointegrated prostheses

Abstract

The direct anchorage of a lower-limb prosthesis to the bone has been shown to be an excellent alternative for amputees experiencing complications in using a conventional prosthetic socket. After surgical implantation, amputees have to go through a weight bearing exercise program to prepare the bone to tolerate forces and promote bone-remodeling. Currently, the load magnitude prescribed by the clinician is measured by a weight scale which reports only the axial force in the limb. Previous study using a load transducer revealed that in addition to the axial force there were other forces and moments. This study develops a FE model and utilizes our load data to investigate the stress distribution at the bone-implant interface. The model shows that the stress distribution could be highly non-uniform during the exercise. Bone-implant interface stress has certain implications in pain adaptation and bone-remodeling, and a good understanding of it can assist in future attempts to refine and shorten the period of rehabilitation exercise. © Springer-Verlag Berlin Heidelberg 2007.