Between January 1987 and December 1989, at the Department of Trauma Surgery of the University of Erlangen 41 patients were treated at one or both hips with the uncemented hip replacement "Erlanger Modell" including a special supporting ring because of the bad condition of the bone surrounding the acetabular region. In 41 cases the implantation was a revision. 2 patients have not been operated on before. They suffered from congenital hypdysplasia with severe bone destruction at the area of the acetabulum. The supporting ring and the cup are made of the titanium alloy TiAl5 Fe2.5. Using the supporting ring, it is possible to fix the socket within the bone graft and to diminish the pressure exerted on the socket by transferring a lot of stress directly to the iliac bone and the oubic bone. The results of 41 patients (43 joints) ranging from 21 to 57 postoperative months giving an average of 32 months, are very encouraging. 76.6% of the patients feel no or not much pain, 67.4% can walk without hooked stick and 79% can walk a distance of more than 1000 m. The range of movement of the hip joint could be improved, especially abduction and extention. Good results based on patients satisfaction were obtained in 95.4%.