Charnley total hip arthroplasty in Chinese patients less than 40 years old

Forty-seven total hip arthroplasties were reviewed in 33 Chinese patients w ho were <40 years old at the time of operation. The preoperative diagnosis was avascular necrosis in 40% of the hips. A Charnley prosthesis was insert ed using early cementing techniques in every hip. The average follow-up was 14.9 years (range, 6.9-21.1 years). The mean preoperative Harris hip score was 43.8 (range, 26-74), and the mean score at latest follow-up was 87.7 ( range, 74-99) for the surviving hips. Thirty hips (63%) were revised, and 1 hip was removed because of late deep infection. The main cause of failure was aseptic loosening of the acetabular component. Using revision and radio logic loosening as endpoints, the cumulative survival rate for the acetabul ar component was 86.3% at 10 years and 27.0% at 15 years. The survival of t he femoral components was 81.3% at 15 years. Patients with avascular necros is had a higher failure rate than patients with other diagnoses (P = .001). An area of cement mantle that was <2 mm thick affected adversely the survi val rate of the acetabular components (P = .04).