Twenty-five-year survivorship of two thousand consecutive primary Charnley total hip replacements: factors affecting survivorship of acetabular and femoral components.

BACKGROUND Charnley total hip arthroplasty has been demonstrated to provide good clinical results and a high rate of implant survivorship for twenty years and longer. Most long-term series are not large enough to stratify the many demographic factors that influence implant survivorship. The purpose of this study was to analyze the effects of demographic factors and diagnoses on the long-term survivorship of the acetabular and femoral components used in Charnley total hip arthroplasty. METHODS Two thousand primary Charnley total hip arthroplasties (1689 patients) were performed at one institution from 1969 to 1971. Patients were contacted at five-year intervals after the arthroplasty. Twenty-five years after the surgery, 1228 patients had died and 461 patients were living. Hips that had not had a reoperation, revision or removal of a component for any reason, or revision or removal for aseptic loosening were considered to have survived. Survivorship data were calculated with use of the method of Kaplan and Meier. Patients were stratified by age, gender, and underlying diagnosis to determine the influence of these factors on implant survivorship. RESULTS The twenty-five year rates of survivorship free of reoperation, free of revision or removal of the implant for any reason, and free of revision or removal for aseptic loosening were 77.5%, 80.9% and 86.5%, respectively. The twenty-five-year survivorship free of revision for aseptic loosening was poorer for each decade earlier in life at which the procedure was performed; this survivorship ranged from 68.7% for patients who were less than forty years of age to 100% for patients who were eighty years of age or older. Men had a twofold higher rate of revision for aseptic loosening than did women. CONCLUSIONS Age, gender, and underlying diagnosis all affected the likelihood of long-term survivorship of the acetabular and femoral components used in Charnley total hip arthroplasty.