Care Setting and State-Level Predictors of Unicompartmental Knee Arthroplasty Price Variation Across the United States

Introduction: Unicompartmental knee arthroplasty (UKA) is a cost-conscious, minimally invasive surgical option for patients with isolated compartment disease. Because UKA is an increasingly common and outpatient procedure, it serves as a model for evaluating the effects of hospital price transparency legislation. This study investigated the association between state-level policy and socioeconomic factors on hospital-reported UKA pricing. Materials and Methods: This cross-sectional analysis included hospital-reported gross charges for UKA (CPT 27446) from the Turquoise Health database across the 50 United States. Multivariable linear regression assessed associations between UKA price and state partisanship (0–5 scale: Democrat to Republican), Certificate of Need (CON) laws, Medicaid expansion, and care setting (inpatient or outpatient), A secondary analysis of North Carolina hospitals assessed the influence of Area Deprivation Index and urbanization on within-state price variation. Results: Among 141,541 reported UKA prices from 2,522 facilities, lower gross charges were associated with states with Republican affiliation (β = $286.9; P<0.0001), presence of CON laws (β = −$799.8, P<0.0001), and outpatient settings (β = −$386.0, P<0.0001). Medicaid expansion was associated with increased pricing (β = +$468.3, P<0.0001). In North Carolina, hospitals in high-ADI counties listed significantly lower prices (β = −$2,727.4, P=0.014); urban location was not significant. Conclusion: Gross charges for UKA vary by state policy environment and care setting. Lower prices were observed in states with Republican leaning, CON laws, high-deprivation regions, and outpatient settings, whereas higher prices were associated with Medicaid expansion. These findings highlight the complex role of policy in shaping equitable access to affordable orthopaedic care.