The long term results of Charnley low-friction arthroplasty in patients with juvenile chronic rheumatoid arthritis

ABSTRACT: Eighty Charnley low-friction arthroplasties, performed on 49 patients with juvenile chronic rheumatoid arthritis, between 1966 and 1986, were followed-up for an average duration of 217 months (18.1 years; 26 to 366 months). There were 10 male patients (17 arthroplasties) and 39 females (63 arthroplasties) whose average age at time of operation was 28.5 years (18 to 35 years). A total of 14 patients (24 arthroplasties) had died, at an average of 208 months (17.3 years, 26 to 339 months) following operation. All patients had marked improvement in levels of pain, function and range of movement of the joint, with 88% (43 patients, 70 arthroplasties) being completely free of pain and all but one of the remainder experiencing only minimal discomfort. Fourteen acetabular components (18%) were revised at an average of 148 months (12.3 years: 26 to 252 months) from the time of operation. Three were revised for deep sepsis, four for excessive wear, and seven for aseptic loosening (9%). Three acetabular components are currently loose and the total aseptic loosening rate was therefore 13% (10 hips). The average acetabular wear rate was 0.11 millimeters per year for the entire series. Twelve femoral components were revised at an average of 153.8 months (12.8 years; 26 to 231 months), three for deep sepsis, five for aseptic loosening (6%) and three following fracture of the implant. One component was revised, although not actually loose, during an operation to replace a loose acetabular component. One of the surviving implants is currently loose and the total rate of mechanical failure of the femoral implant was therefore 11% (9 hips). Acetabular component survivorship was 94% (95% C.I.: 88 – 99%) at 10 years and 79% (69 – 89%) at 25 years, with the survivorship of the femoral implant being 95% (90 – 100%) and 81% (70 – 91%) respectively. (Hip International 1999; 9: 26-37)

KEY WORDS: Charnley arthroplasty, Cement, Juvenile chronic rheumatoid arthritis