Long-Term Outcome of Primary Total Hip Arthroplasty after a Minimum Twenty-Year Follow-Up

Total hip arthroplasty (THA) was first performed in Taiwan in 1971, and has been widely performed over the past three decades. We report on a large series of THA patients who have undergone a minimum follow-up of 20 years. In this study, we evaluated long-term results of 123 THAs in 107 patients who underwent THA between January 1971 and June 1983. Of 592 primary THAs (558 patients), 540 hips were implanted with a Muller prosthesis, 30 with an Aufranc-Turner prosthesis, 13 with a McKee-Farrar prosthesis and 9 with a THARIES prosthesis. All of the prosthetic hips were implanted with polymethylmethacrylate cement using a hand-packing technique. At a minimum of 20 years after the initial procedure, 63 patients (67 hips) were deceased, and 388 patients (402 hips) had been lost to follow-up. Of the remaining 107 patients, there were 71 men (81 hips) and 36 women (42 hips). The average age of the patients at the time of the initial arthroplasty was 47 years (range, 18 to 71). At the time of the latest follow-up evaluation, 99 patients were still alive. Thirteen McKee-Farrar metal-on-metal bearing replacements were implanted between 1971 and 1972. Of the 13 patients, one patient was still functioning well 32 years after the initial surgery. One patient had loosening of the cement-stem interface 8 years postoperatively, and was treated with femoral revision using the retrieved stem. After 23 years, the prosthesis was revised with cementless cup and stem due to progressive osteolysis. The remaining 11 patients were lost to follow-up. Nine THARIES surface replacements were performed from 1978 to 1982. Five prostheses underwent regular follow-up, with all undergoing revisions at a mean of 19.2 months (range, 12 to 41 months) postoperatively. The Muller type and Aufranc-Turner type prostheses accounted for the majority of prostheses in treating hip diseases (570 hips). Approximately 21% of the hips (121 of 570) underwent follow-up of more than 20 years, with a mean follow-up of 23.3 years (range, 20 to 32). Of the 121 hips, 102 cups (84.3%) and 83 stems (68.6%) had been revised. Of the 102 cups, 92 (76%) cups were revised because of aseptic loosening, 4 (3.3%) due to septic loosening, 5 (4.1%) due to periprosthetic fracture, and 1 (0.8%) due to dislocation. Of the 83 stems, 74 stems(61.2%) were revised due to aseptic loosening, 5 (4.1%) due to periprosthetic fractures, and 4 (3.3%) due to septic loosening. Kaplan-Meier survival analysis of the 121 Muller and Aufranc cemented prostheses showed survival of the femoral component was 78.5%, 56.2%, and 44.6%, and that of the acetabular component was 68.6%, 41.3%, and 24.0% at 10, 15, and 20 years, respectively. A plateau of cup failure was found 8 years after the initial surgery. Of the 121 hips with a minimum follow-up of 20 years, 38 (31.4%) stems and 19 (15.7%) cups still retained the original components until the patients died or upon the latest follow-up examination. Femoral osteolysis was present in around 92% (35 of 38) of retained stems. Acetabular osteolysis was seen in all of the retained sockets upon latest radiographic follow-up (n = 19). The mean Harris Hip Score on the latest follow-up of the 19 patients retaining both socket and stem was 69.1 (range, 34-83).