Does Race Affect Utilization of Unicompartmental vs Total Knee Arthroplasty? A Matched Cohort Study Within a Universal Health System

Background: The purpose of this study was to evaluate racial differences in total knee arthroplasty (TKA) vs unicompartmental knee arthroplasty (UKA) utilization within the Military Health System (MHS). We hypothesized that there would be no racial differences in utilization rates of TKA and UKA within the MHS. Methods: We identified patients who underwent primary knee arthroplasty in the MHS between 2009 and 2024. Patients were matched 1:1 (TKA:UKA) by demographic factors other than race. Osteoarthritis severity was measured on preoperative radiographs using Kellgren-Lawrence grading. Matched pairs were eliminated after radiographic review if the TKA would not have been a radiographic candidate for the corresponding UKA based on Kellgren-Lawrence grade. Conditional logistic regressions were performed to examine the association between race and TKA vs UKA utilization in matched cohorts. Results: We identified 8640 arthroplasties. After demographic matching, minority race was not associated with UKA utilization compared to White race (Black: odds ratio [OR] = 0.86; 95% confidence interval [CI]: 0.63-1.18; non-Black: OR = 0.97; 95% CI: 0.69-1.36). The radiographically matched cohort included 152 TKA patients matched with 152 UKA patients. In this cohort, odds of UKA vs TKA were quantitatively lower for minority race groups vs White race (Black: OR = 0.77; 95% CI: 0.40-1.49; non-Black: OR = 0.61; 95% CI: 0.30-1.26); however, these differences were not statistically significant. Conclusions: There were no statistically significant racial differences in TKA vs UKA utilization among our matched cohort within the universal military healthcare system. Although not significant, there were quantitatively lower odds of UKA in minority race groups, suggesting a need for continued evaluation of utilization trends.