Outcome of total hip replacement in rheumatic arthritis.

Background. Degenerative changes caused by rheumatoid arthritis (RA) typically occur in the hands and feet, but are not rare in the hip. The purpose of our research was to assess outcome in RA patients undergoing total hip arthroplasty. Material and methods. From 1992 to 2000 we performed total arthroplasty in 166 RA patients (121 women and 45 men) with degenerative changes in the hip joint. The average age of these patients was 57.4 years (range 35 to 74). Outcome was evaluated clinically in terms of pain relief, locomotion, and range of motion in the hip, evaluated according to the Harris hip function scale. Radiological analysis was also performed. Results. The greatest problem during surgery proved to be the lack of strong bone edges on the acetabulum (78%). The average results from the Harris scale went up 46 points, to 83.2+/-11.3. During the final radiological analysis there were no visible gaps or gaps only in Zone I of the acetabulum in 80% of the joints. We had to perform revision surgery in 3 hips (1.7%) due to infection, and in 8 hips (4.5%) due to aseptic loosening of the acetabulum. Conclusions. 2/3 of the hips affected by rheumatic changes show destruction of the acetabulum, which hinders proper emplacement of the acetabulum. Loosening of the hip endoprosthesis was found radiologically in 13% of the hips, which was accompanied by clinical symptoms in half the cases. The conditions for stable insertion of the shaft were better than for the acetabulum.