[Initial Experience with a New Generation of Zweymüller's Endoprosthesis.]

In the first part of our paper innovations as regards the non-cemented endoprosthesis of the hip joint by Zweymüller's method are described. As a special advantage the double cone of the socket is mentioned which as to its anatomical shape is close to the acetabulum and makes only slight resection of the bone on the floor of the acetabulum possible. At the Orthopaedic Department of the hospital in Zwettl between 1984 and 1987 more than 100 polyethylene Endler screw sockets were implanted. From the end of 1987 to the beginning of 1993 the authors used non-cemented endoprostheses as designed by Zweymuller. Based on the mentioned advantage of the new biconical socket, as suggested by Zweymuller, the authors implant this generation since the beginning of 1993. During the period from Jan.1, 1993 to Dec. 31, 1993 68 endoprostheses of the hip joint of the new type were used during primary operations. The follow-up of patients respected clinical and radiological criteria (pattern of Merle d'Aubigne). Of 68 patients 67 (98.5%) were followed up. In the present retrospective study in particular heterotopic ossifications were investigated, whereby the years 1992 and 1993 were compared. Key words: non-cemented total endoprosthesis of the hip joint, non-cemented biconical socket.