Abstract
1. 68 cases or cemented total hip prostheses which had been operated on more than 5 years ago were studied with regards to “loosening”. Radiographic evidence of loosening of the acetabular and/or femoral components was shown in 27 hips, 40% of total cases. We should pay much attention to not only the choice of adequate prestheses but also cementing techniques.
2. Histological studies of the tissue at the interface of bone-cement interface in loosened prostheses revealed that there was a synovium-like membrane, and deep to the membrane foam cells and foreign body giant cells predominated. High levels PGE were detected in cases which showed massive bone resorption and destruction. It is suggested that PGE secreted by foam cells or giant cells could be responsible for the process of aseptic loosening.
