Regional and socioeconomic differences in unicompartmental knee arthroplasty utilization: Which patient populations are receiving care?

Background: Despite a recent decrease in the utilization of unicompartmental knee arthroplasty (UKA) in the last two years, UKA utilization has increased significantly in the last 15 years. Although many studies have evaluated UKA utilization, little has been reported on the variation in utilization across geographical regions or socioeconomic groups. This study aimed to evaluate UKA utilization over time in communities of different socioeconomic status, as measured by Area Deprivation Index (ADI). Methods: Area Deprivation Index scores for zip codes nationwide were grouped into 3 cohorts, with an ADI score of 1-25 indicating low distress communities (LD) and 76-100 indicating high distress communities (HD), and the last cohort consisting of patients from communities with an ADI score of 26-75. These ADI cohorts were used with an insurance claims database to evaluate UKA utilization from 2010 to 2023. Regional differences in utilization were evaluated based on the 4 different regions, West, Midwest, Northeast, South. Results: Across the United States, the utilization of UKA increased over time for patients from the LD cohort and the utilization decreased over time for patients in the HD cohort. The UKA utilization between LD and HD communities was significantly different in all regions, (West: p < 0.001; Midwest: p < 0.006; Northeast: p < 0.019; South: p < 0.001). The Northeast had the largest growth rate among the LD cohorts (3.389%; p < 0.001). The Midwest region exhibited reduced utilization across all ADI quartiles (p < 0.001). Conclusion: This study demonstrated increased UKA utilization in low socioeconomic distress communities, while declining utilization in high socioeconomic distress communities. These trends were consistent across all U.S. regions (p < 0.001) and suggest that socioeconomic and regional disparities may influence access to surgical care or patient selection, underscoring the need for targeted interventions to ensure equitable access to UKA.