LONG-TERM STUDY OF TOTAL HIP-REPLACEMENT IN RHEUMATOID-ARTHRITIS

Between 1977 and 1983 544 cemented Muller's curved-stem hip endoprosth eses (THR) were implanted in 454 patients, including 207 THR in 163 pa tients suffering from rheumatoid arthritis and other chronic inflammat ory joint diseases (RA) at the I. Orthopadische Klinik, BRK Rheuma-Zen trum Bad Abbach, Germany, 98% of the THR could be followed up by clini cal acid radioiogical examinations, structured questionnaires or infor mations by others 9 to 15 (11 on an average) years postoperatively. Be cause of the outstanding responder-rate the results of survivorship an alysis due to Kaplan-Meier are very reliable: the rate of THR-survival in RA amounts 89.3% after 10 years, 83.2% after 15 years. Patients wi th RA and age less than or equal to 60 years at operation showed a sig nificantly higher risk of failure, but survival rate was still 78.5% a fter 75 years. Long-term studies are a proper method to quality contro l in THR, if some demands are met: exact definition of failure, feed-b ack near 100% of data needed for survivorship analysis, presentation o f results of identical and different types of endoprostheses with rega rd to homogeneous subgroups (illnesses, age, gender of patients and co mplications).