Racial differences in pain and function following knee arthroplasty: A secondary analysis from a multicenter randomized clinical trial

OBJECTIVE: The assessment of racial differences in pain and function outcome following knee arthroplasty has received little attention in spite of a very substantial literature exploring a variety of other prognostic factors. We determined whether race associated with knee arthroplasty (KA) outcome after accounting for potential confounding factors. METHODS: We conducted a secondary analysis of a randomized clinical trial of 384 participants with moderate to high pain catastrophizing who underwent knee arthroplasty. Preoperative measures included race/ethnicity status as well as a variety of potential confounders including socioeconomic status, comorbidity and bodily pain. Outcome measures were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain and Function Scales as well as performance measures. Linear mixed effects models compared outcomes over a one-year follow-up for African Americans versus the non-African Americans. RESULTS: WOMAC Pain scores differences for African Americans versus non-African Americans averaged approximately 2 points in unadjusted analyses and 1 to 1.5 points in adjusted analyses. In adjusted analyses, follow-up WOMAC Function scores differed by 6 points for African Americans compared to non-African Americans (p = 0.002). CONCLUSION: