Perioperative outcomes in patients with rheumatoid versus osteoarthritis for total hip arthroplasty: a population-based study.

OBJECTIVES: Little is known about perioperative outcomes among the subset of patients undergoing total hip arthroplasty (THA) for a diagnosis of rheumatoid arthritis (RA) rather than osteoarthritis (OA). We sought to 1) identify the prevalence of RA in patients undergoing THA, 2) compare their demographics to those being operated on for OA, 3) determine differences in perioperative outcomes and 4) analyse if RA represents an independent risk factor for complications, mortality, utilisation of resources, increased length of stay and cost.
METHODS: Entries of patients who underwent elective THA between 2006 and 2010 were identified in a national database and subgrouped according to presence of a concurrent diagnosis of RA. Differences in demographics and perioperative outcomes were analysed.
RESULTS: We identified 157,775 entries for patients who underwent THA between 2006 and 2010. RA was present in 3.42% (n=5,400). Patients in the group RA were on average younger [RA: 63.94 years vs. OA: 65.64 years; p<0.0001] and more likely female [RA: 75.47% vs. OA: 56.09%; p<0.0001]. While mortality was not statistically different, perioperative pulmonary and infectious complications occurred more frequently in RA patients. Compared with OA, multivariate logistic regression revealed higher overall odds for complications [OR=1.15 (CI 1.05;1.25), p=0.0037], need for mechanical ventilation [OR=1.42 (CI 1.01;2.00), p=0.0414], transfusion [OR=1.35 (CI 1.26;1.44), p<0.0001], prolonged hospitalisation [OR=1.16 (CI 1.08;1.23), p<0.0001] and increased hospital charges [OR=1.17 (CI 1.09;1.26), p<0.0001].
CONCLUSIONS: In THA patients suffering from RA, perioperative risk for complications and utilization of health care resources continues to be increased compared to OA patients.