Long-term results of low-friction arthroplasty in patients 30 years of age or younger.

The long-term results of 49 Charnley low-friction arthroplasties performed in patients 30 years of age or younger at the time of surgery was reviewed, with special emphasis placed on the radiologic evaluation of the acetabular and femoral components with average follow-up period of nearly ten years and the longest follow-up period of 15.5 years. Fifty-three percent of the sockets had no cement-bone demarcation and 28.6% had only a small line in the upper outer quadrant of the socket. Of the seven sockets that failed (14.3%), six had very deficient bone stock at operation. There were only two cases of femoral loosening. The rate of wear was 1.7 mm at ten years, which is not much greater than in older patients. Most of these cases were patients with conditions causing built-in restraints against over activity.