Racial Variation in Total Knee Replacement in a Diverse Nationwide Clinical Trial

Racial variation in total knee replacement (TKR) utilization in the United States has been reported in administrative database studies. We investigated racial variation in TKR procedures in a diverse cohort with severe knee pain followed in an ongoing clinical trial.

VITAL (VITamin D and OmegA-3 TriaL) is a nationwide, randomized controlled trial of 25,874 adults, 20% of whom are black. We identified a subgroup highly likely to have knee osteoarthritis based on severity of knee pain, physician-diagnosed knee osteoarthritis, and inability to walk 2 to 3 blocks without pain. Participants completed a modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and self-reported incident TKR annually in follow-up. Using Cox regression, we analyzed the association of black versus white race with TKR, adjusting for demographic and socioeconomic characteristics, comorbidities, and WOMAC pain and function.

Among 1070 participants who met the inclusion criteria, black participants reported worse baseline WOMAC pain (45 vs. 32, P < 0.001) and worse function (45 vs. 32, P < 0.001). During a median of 3.6 years (interquartile range, 3.2, 3.8 years) of follow-up, TKRs were reported by 180 participants. Black participants were less likely to undergo TKR (11% vs. 19%). After adjustment, the hazard ratio for TKR for black versus white participants was 0.51 (95% confidence interval, 0.32-0.81). Lower use of TKR among black participants was observed across all levels of income and education.

Despite worse baseline knee pain and function, black participants had much lower adjusted risk of having TKR than white participants, demonstrating persistent racial disparity in TKR utilization.