Long-term clinical results of Charnley total hip arthroplasty using a matte satin-finished stem: a 30-year average follow-up study

Background Although 50 years have passed since Charnley started performing total hip arthroplasties, there are relatively few patient studies with a follow-up period of over 30 years. We studied radiograms of patients who had undergone Charnley total hip arthroplasty between 1975 and 1981 and evaluated the results at 26–35 years (mean 30.5 years) after the operation. Methods The operations were performed in 87 joints of 82 patients (26 males and 56 females) aged 26–81 years (mean age 56 years) at the time of surgery. A monoblock-type Charnley stem with a 22-mm head was used in all patients. The stem had a matte satin surface finish and a flange or round-back shoulder. The socket was made of ultra-high-density polyethylene without a flange. All operations were performed by one surgeon using the original Charnley method in all patients, excluding the first five. Results Thirty years after the operation, 48 patients have died, 5 had an infection, 9 were lost to follow-up, and 20 patients with 24 joints are still alive. In 77 patients (82 joints), after excluding the 5 with infection, the socket and stem survival rates were 54 and 75 % at 30 years after the operation when radiographic loosening or revision surgery was defined as the end point. With revision surgery as the end point, the rates were 68 and 82 %, respectively. Conclusions These results were as favorable as those with surgical techniques (including the first-generation cement technique) and implants in the early period. Although new techniques and implants have since been introduced, their long-term results should exceed those in this study. The results of this study should provide a valuable index with which to compare the long-term studies of current total hip arthroplasty.