Cementless bulk alumina socket - Preliminary results at 6 years

To avoid polyethylene wear observed in total hip replacement, an alumina-al umina combination has been used since 1977. The aim of this study is to rep ort the results of a hybrid alumina-alumina total hip arthroplasty with a c ementless press-fit bulk alumina socket and a cemented titanium alloy stem in 55 patients (62 hips) operated on between 1982 and 1990. The bearing sur faces were a 32-mm alumina head articulating within the alumina socket. Fou r failures occurred: 3 aseptic loosenings of the socket and 1 femoral head fracture. Considering aseptic loosening as the endpoint, the survival rate was 93.2% after 6 years. At a mean of 72.1 months' follow-up, 92.4% of the surviving hips were graded as very good or good using the Merle d'Aubigne-P ostel hip score. Radiolucent lines were observed on the acetabular side in 68.1 of the hips. The future of this interface, which is probably fibrous, remains questionable. With the exception of 1 femoral head fracture, all re visions were related to failure of the bony fixation of the socket, and no problem was encountered related to the alumina-alumina friction coupling. A lumina sockets with other types of cementless fixation have therefore been designed and are presently under clinical investigation.