1. Materials for hip prostheses

Figure 1 shows an exploded view of a modular hip prosthesis. It consists of an acetabular part and a femoral part. The acetabular cup is inserted into the joint cavity, known as the acetabulum, in the coxal bone of the pelvis. In some cases, a titanium part is inserted to facilitate anchoring of the prosthesis in the bone, using screws for example. Its concave, spherical part forms the joint into which the head of the femoral component articulates. The latter is spherical in shape, with a conical cavity at its base. During surgery, the head is set into the cone of the femoral stem. The surgeon therefore has the option of adjusting the length of the prosthesis, by choosing a head with a conical cavity dimension appropriate to that of the conical tip. The femoral stem is implanted...