The long-term outcomes of rheumatoid arthritis: a 23-year prospective, longitudinal study of total joint replacement and its predictors in 1,600 patients with rheumatoid arthritis.

OBJECTIVE

Although total joint arthroplasty (TJA) is a common procedure and an important outcome in rheumatoid arthritis (RA), little is known about its prevalence, failure rate, or predictors over the course of the illness. The current study evaluated these factors in 1,600 consecutive RA patients seen during a period of observation that extended 23 years.

METHODS

Beginning in 1974, data from 34,040 RA patient visits were entered prospectively into a computer databank. Data consisted of laboratory, radiographic, physical examination, and self-report questionnaires. At each assessment, we also noted a complete surgical history. Patients were also followed up by questionnaires that were mailed at 6-month intervals.

RESULTS

Kaplan-Meier life-table estimates indicated that 25% of RA patients will undergo total joint arthroplasty (TJA) within 21.8 years of disease onset. For patients with 1 TJA, 25% had a TJA in a different joint within 0.92 years and 50% within 7.0 years. Ten years after TJA, approximately 6% of implanted knees and 4% of implanted hips had been replaced with a second TJA, and 12% and 13% of the joints had either a second TJA or a TJA-related operation, respectively. In Cox regressions, a large series of clinical and laboratory variables, which primarily reflected disease activity, predicted TJA. Smoking, either past or present, had a protective effect. Patients with highly abnormal values on the Health Assessment Questionnaire Disability Scale, global severity, and erythrocyte sedimentation rate had a 3-6 times increased risk of TJA.

CONCLUSION

TJA, a marker of joint failure and of RA outcome, is predicted by self-report assessments of severity and function, and by a series of laboratory, radiographic, and clinical variables. Prediction improves with the extent of observation, and 2-year observations approach full-study observations in their accuracy. Most TJAs survive for a long time in RA.