An Increase in the Treatment of High-Risk Total Joint Arthroplasty Patients Who Have Medicare at Teaching Hospitals.

Abstract

The Comprehensive Care for Joint Replacement (CJR) Medicare model may not adequately compensate for increased resource utilization in complex total joint arthroplasty (TJA) cases, raising concern for potential biased selection of healthier patients and avoidance of complex or high-comorbidity patients. This study quantified national trends among Medicare beneficiaries undergoing TJA, comparing comorbidity characteristics at teaching versus non-teaching hospitals. A comprehensive healthcare database was queried for adult patients (≥ 65 years) who underwent total knee (TKA) or total hip arthroplasty (THA) from 2016 to 2023. Patients who had Medicare insurance reimbursement were examined at teaching and non-teaching hospitals. The Elixhauser Comorbidity Index (EI) was determined using International Classification of Disease, Tenth Revision, and Current Procedural Terminology codes. High-risk patients were defined as EI above the 95th and 99th percentiles. Average EI was examined by year. Univariate analyses were performed to assess the impact of hospital type on the proportion of high-risk patients in each cohort. Of the 686,229 patients identified with Medicare, "high-risk" patients comprised 6.67% (95th percentile) and 1.23% of their respective cohorts (99th percentile). The percentage of high-risk patients was significantly greater at teaching hospitals compared to non-teaching hospitals (95th percentile: 7.39 versus 6.16% and 99th percentile: 1.43 versus 1.10%; P <0.001 for all). There was an overall increase of 0.1 in EI for TJA patients at teaching hospitals and a decrease of 0.2 in EI at non-teaching hospitals between 2016 and 2023. High-risk patients comprise a significantly greater proportion of the TJA population at teaching hospitals compared to non-teaching hospitals, quantifying the increased burden of a sicker, more comorbid cohort at teaching hospitals since the introduction of the CJR model in 2016. Medicare reimbursement models should incorporate stratification-based payment strategies that account for this population's increased healthcare needs, ensuring protected hospital spending and equitable TJA access for high-comorbidity patients.