Payor Type is Associated With Increased Rates of Reoperation and Health-care Utilization Following Unicompartmental Knee Arthroplasty: A National Database Study

Background: Unicompartmental knee arthroplasty (UKA) is a common orthopedic procedure with overall good clinical outcomes; however, more recent literature has identified disparities in treatment access and outcomes based on sociodemographic factors. There is a paucity of literature examining whether payor type, including Medicare, Medicaid, and commercial insurance types, impacts early medical complications and rates of reoperation following a UKA. Methods: Patients with Medicare, Medicaid, or commercial payor type who underwent primary medial or lateral UKA between 2010 and 2019 were identified using a large national database. Ninety-day incidence of emergency department visit and 1-year incidence of revision, revision to arthroplasty, reimbursement, and cost of care were evaluated. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates. Results: Medicaid insurance was associated with an increased risk of emergency room visit (odds ratio [OR] 2.77; P < .001), revision surgery (OR 1.85; P < .001), and conversion to total knee arthroplasty (OR 1.50; P = .0292) compared to commercially insured patients. Medicaid insurance was associated with an increased risk of emergency room visit (OR 3.58; P < .001), revision surgery (OR 1.97; P < .001), and conversion to total knee arthroplasty (OR 1.80; P = .003). Medicaid patients were associated with a higher overall cost of care and lower reimbursement than commercial and Medicare patients (P < .001 and P < .001, respectively). Conclusions: These findings demonstrate that payor type is associated with increased rates of reoperation and health-care utilization following UKA despite controlling for covariates. Additional work is required to understand the complex relationship between socioeconomic status and outcomes to ensure appropriate health-care access for all patients and pursue appropriate risk stratification. Level of Evidence: III, retrospective chart review.