Higher disease activity at baseline, but not perioperative medication management, increased the risk for postoperative flares in patients with rheumatoid arthritis (RA) who underwent elective total hip arthroplasty (THA) or total knee arthroplasty (TKA), according to a report published in The Journal of Rheumatology.
Patients with RA who undergo TKA or THA must generally discontinue any biologics or disease-modifying antirheumatic drugs preoperatively to reduce the risk for postoperative infection. This increases the chance of symptom flares in the immediate postoperative period. Balancing risk for infection vs risk for disease flare is challenging. Therefore, investigators conducted the RA Perioperative Flare Study to examine flare rates, risk factors, and characteristics of RA flares within 6 weeks of THA or TKA.
A total of 120 patients with RA (mean age, 61.7; median RA duration, 14.8 years; 83% women; 81% white) were prospectively followed after TKA (56%) or THA (44%) surgery. A majority (82%) met 2010/1987 American College of Rheumatology/European League Against Rheumatism criteria for RA. Clinicians evaluated each participant within 2 weeks before surgery and again 6 weeks postoperatively. Patients also logged weekly self-assessments of flare status and joint counts after surgery. There were 61 patients (51%) taking biologics; biologics were discontinued before surgery in most cases, whereas steroids and methotrexate were continued.
At 6 weeks postsurgery, 63% of participants had experienced flares, with a median time to flare of 2 weeks postprocedure. Although more participants who experienced flares used biologics numerically, the difference was not significant compared with those who did not experience flares (57% vs 42%; P =.14), and stopping biologic medication was not predictive of flares. However, participants who experienced flares demonstrated higher baseline disease activity across several measures, and increased activity produced a >2-fold overall increase in risk for flares postoperatively (odds ratio [OR], 2.12; P =.02).
After multivariable regression, several baseline measures remained independent predictors of physician-verified postoperative flares. The 28-joint Disease Activity Score (OR, 2.11; P =.015) and Rheumatoid Arthritis Disease Activity Index (OR, 2.97; P =.023) both predicted flares after surgery, as did increasing C-reactive protein levels (OR, 4.24; P =.035).
Study strengths included the prospective design, weekly patient reports, avoidance of recall bias with real-time status reports, high (83%) questionnaire completion rates, and several implementations designed to enhance reliability.
Study limitations included possible unmeasured confounding, possible selection and channeling bias, potential lack of generalizability, use of patient self-reports vs clinician exams, lack of a control group, inability to evaluate infections or complications between groups, and loss of some patients with RA because of inclusion and exclusion criteria.
The authors suggested that future research should focus on longer-term outcomes in this patient population to better characterize the extended postoperative course in terms of disease flares and adverse events.
Disclosures: Supported by grant 1UH2AR067691 from the National Institutes of Health Accelerating Medicine Partnership program, the Weill Cornell Clinical Translational Science Center (UL1-TR000457-06), and the Block Family Foundation. There were no conflicts of interest declared.
Goodman SM, Bykerk VP, Dicarlo E, et al. Flares in patients with rheumatoid arthritis after total hip and total knee arthroplasty: rates, characteristics, and risk factors [published online March 15, 2018]. J Rheumatol. doi:10.3899/jrheum.170366