Uncemented total hip replacement.

Between Jan. 1, 1976 and Dec. 31, 1981, 257 patients (age range from 21 to 65 years) with osteoarthritis of one or both hips were treated with ceramic hip replacement (Mittelmeier type). The cause of the osteoarthritis was variable. Hip replacement was carried out for the following conditions: rheumatoid arthritis including ankylosing spondylitis, aseptic necrosis of femoral head including post-traumatic and idiopathic forms, osteoarthritis of unknown origin, osteoarthritis following dysplasia or subluxation of the hips and loosened cemented hip prosthesis. The operative technique is described. Full weight bearing is not permitted for 16 weeks postoperatively, but mobilization and isometric exercises begin 2 days after operation and isotonic exercises are introduced later. Complications included fracture of the femoral shaft during operation, fracture of the acetabulum, protrusion, dislocation and infection early after operation (within 16 weeks) and aseptic loosening and pulmonary embolism (after 16 weeks). The results with this new type of hip replacement are encouraging. Good results based on patient satisfaction were obtained in 79% and poor results in 13%.