Medicaid Patients Undergo Total Joint Arthroplasty at Lower-Volume Hospitals by Lower-Volume Surgeons and Have Poorer Outcomes

Abstract

Background: Medicaid insurance coverage among patients undergoing total hip arthroplasty (THA) or those undergoing total knee arthroplasty (TKA) has been associated with worse postoperative outcomes compared with patients without Medicaid. Surgeons and hospitals with lower annual total joint arthroplasty (TJA) volume have also been associated with worse outcomes. This study sought to characterize the associations between Medicaid insurance status, surgeon case volume, and hospital case volume and to assess the rates of postoperative complications compared with other payer types. Methods: The Premier Healthcare Database was queried for all adult patients who underwent primary TJA from 2016 to 2019. Patients were divided on the basis of their insurance status: Medicaid compared with non-Medicaid. The distribution of annual hospital and surgeon case volume was assessed for each cohort. Multivariable analyses were performed accounting for patient demographic characteristics, comorbidities, surgeon volume, and hospital volume to assess the 90-day risk of postoperative complications by insurance status. Results: Overall, 986,230 patients who underwent TJA were identified. Of these, 44,370 (4.5%) had Medicaid. Of the patients undergoing TJA, 46.4% of those with Medicaid were treated by surgeons performing ≤100 TJA cases annually compared with 34.3% of those without Medicaid. Furthermore, a higher percentage of patients with Medicaid underwent TJA at lower-volume hospitals performing ≤500 cases annually, 50.8% compared with 35.5% for patients without Medicaid. After accounting for differences among the 2 cohorts, patients with Medicaid remained at increased risk for postoperative deep vein thrombosis (adjusted odds ratio [OR], 1.16; p = 0.031), pulmonary embolism (adjusted OR, 1.39; p < 0.001), periprosthetic joint infection (adjusted OR, 1.35; p < 0.001), and 90-day readmission (adjusted OR, 1.25; p < 0.001). Conclusions: Patients with Medicaid were more likely to undergo TJA performed by lower-volume surgeons at lower-volume hospitals and had higher rates of postoperative complications compared with patients without Medicaid. Future research should assess socioeconomic status, insurance, and postoperative outcomes in this vulnerable patient population seeking arthroplasty care. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.