Patients with rheumatoid arthritis (RA) may be at increased risk for prosthetic joint infection and death, but may be at decreased risk for surgical revision after total knee or total hip arthroplasty (TKA/THA), compared with patients who have osteoarthritis (OA), according to a report recently published in The British Medical Journal.
For this retrospective cohort study, the researchers used data from the Danish National Patient Register to identify risk predictors of 1-year mortality, prosthetic joint infection, and 10-year revision in patients with RA and OA who had undergone THA or TKA.
Patients with RA had an increased risk for death (hazard ratio [HR], 1.25) and for prosthetic joint infection (confounder-adjusted sub-HR [SHR], 1.46; 95% CI, 1.13-1.88), and a decreased risk for revision (SHR, 0.71), compared with patients with OA.
Treatment with biologic disease-modifying antirheumatic drugs (bDMARDs) had no significant impact on prosthetic joint infection (SHR, 1.61), death (HR, 0.75), or 10-year revision (SHR, 1.49). However, glucocorticoid exposure elevated the risk for mortality significantly (HR, 2.87) in a dose-dependent manner — particularly for doses >7.5 mg.
Few patients who had been treated with bDMARDs were included in the study, thus reducing the statistical power of the analysis. The researchers mention a “degree of misclassification in DMARD and glucocorticoid treatment episodes,” and the difficulty in diagnosing prosthetic joint infection — possibly yielding underdocumentation — both of which represent additional study limitations.
Many of the study’s results regarding risk for patients with RA following TKA or THA are in line with current literature and can be considered supporting or supplementary evidence. The observed dose-dependent mortality risk associated with glucocorticoid treatment represents a new finding, however, and should be considered by clinicians when deciding on preoperative therapeutic regimens for patients with RA.
Cordtz RL, Zobbe K, Højgaard P, et al. Predictors of revision, prosthetic joint infection and mortality following total hip or total knee arthroplasty in patients with rheumatoid arthritis: a nationwide cohort study using Danish healthcare registers (published online November 2, 2017). Ann Rheum Dis. doi:10.1136/annrheumdis-2017-212339