OUTCOME OF CEMENTLESS HIP-ARTHROPLASTY IN RHEUMATIC DISEASES

We compared the outcome of cementless hip arthroplasty in patients wit h chronic rheumatic diseases (cases) and patients with osteoarthritis (controls). Between 1985 and 1993 we implanted 26 cementless hips in 2 2 patients with Rheumatoid Arthritis, Psoriatic Arthritis or Ankylosin g Spondylitis.-From a pool of more than 600 patients with Osteoarthrit is we chose 40 matched controls (41 hips). Matching variables were yea r of implantation, age, follow-up,height, weight, gender and type of i mplant. At follow-up (cases: 58 +/- 27 months; controls: 56 +/- 26 Mon ate) no signs of loosening or migration of the stem were found, neithe r in the cases nor in the controls. Loose and/or migrated cups were fo und in 4 patients with rheumatic diseases (after 44, 65, 65 and 107 mo nths) and in 3 patients with osteoarthritis (after 63, 84 and 100 mont hs). Two cups were revised within 18 months in the control group, in t he case group one revision was necessary after 5 years. Loosening and revision rates did not differ significantly (p > 0.20). Clinically, th ose with Osteoarthritis had a better extension (p < 0.02), were more s atisfied with their (artificial) hips (p < 0.05) and did better in som e activities of daily living (climbing stairs, dressing, sitting/stand ing up). Within a mean follow-up of 5 years the results of patients wi th chronic rheumatic diseases seem to be comparable to those of a matc hed control-group of patients with Osteoarthritis. Differences between the groups concern areas, in which rheumatic patients are handicapped due to their chronic illness. Nevertheless, we need long-term-results , before we can recommend cementless implants for these patients.