Femoral component loosening after total hip arthroplasty.

To determine the long-term durability of total hip arthroplasty and to identify factors responsible for femoral component loosening, 106 total hip arthroplasties were reviewed in patients with a minimum postoperative period of 3 years. Seventy-four had Charnley-Müller prostheses and 32 had Charnley prostheses. Femoral component loosening occurred in 16 of 106 hips. Not all loose components were symptomatic. The femoral component at risk was the femoral Charnley-Müller type that had been inserted in varus position in a functioning active heavy patient who previously had had a femoral head prosthesis.