CERAMIC CUP INSERTS FOR HIP ENDOPROSTHESE S

The articulating components of a total hip prosthesis are the spherica l femoral head and the acetabular cup. Particularly high rates of wear are seen with cups made of polyethylene, and the abrasion particles c ause osteolysis, which often makes surgical revision necessary. Despit e considerable progress in the development of total hip replacement sy stems over the last 20 years, there is still a need to eliminate or fu rther minimize the problem of osteolysis, which is also referred to as polyethylene desease. Clinical experience over the last 20 years has shown that by using Biolox (medical grade alumina) femoral heads and a cetabular cups it is possible to achieve very low wear rates, which hi stological studies have shown to be readily tolerated. The secondary c onditions needed to develop modern modular ceramic acetabular cup inse rts are discussed. For the fixation of cup inserts, the well known tap er fixation concept has proved to be of value. A concept taking into a ccount the needs of the surgeon and the manufacturing constraints appl ying to ceramic materials is proposed.