Cement-free bioceramic double-cup endoprosthesis of the hip-joint.

A cement-free bioceramic aluminum oxide double cup endoprosthesis is under investigation as an alternative to the cemented stem endoprosthesis. Nine patients with 11 operated hips are without complaints after an average of 20.8 months (range 8--28 months). Early loosening of 2 femoral components occurred because of technical mistakes during operation. In 3 patients loosening of the femoral component was seen 5--7 months after surgery. Mobilization of the hip joint and walking capacity are similar to the usually implanted stem endoprosthesis. Stable long-lasting anchorage is possible if the femoral component is implanted in valgus position and in contact with living bone. Failures are treated by a traditional type of endoprosthesis.