[Experiences with the Spotorno expansion acetabulum].

At 53 hip joints a cupshell developed by L. Spotorno was practiced as replacement for the acetabular joint surface. This cementless CLS expansion-shell was always in combination with an also cementless femoral prosthesis applied in case of medial femur neck fractures, coxarthrosis, or the exchange operation to implantation. The concept of this prosthesis-shell performs the elastic- and mechanical structures of the bone around the joint. The primary stability is guaranteed by cramp points, which penetrate in the bone layer under the cartilage. Secondary the bone, which grows in the surface of the titanium shell takes, over the durable stability. Our experiences up to now with relation to the technique of implantation and the check ups after one till two years of functional weight-bearing are looking foreward to a time which confidences in the results with regard to the regeneration of bone and the cramp-stability.