Total Hip and Knee Revisions are Really Outpatient Procedures? Implications of the Removal From the Inpatient Only List.

BACKGROUND: In 2021, the Centers for Medicare and Medicaid Services (CMS) removed over 200 procedures from the Inpatient Only (IPO) list including revision total hip (THA) and total knee arthroplasties (TKA). The purpose of this study is to determine if some revision TKA and THA procedures may be appropriate for outpatient status. METHODS: We reviewed a consecutive series of 1026 revision THA and TKA patients at our tertiary academic institution from 2015 to 2020. An outpatient procedure was defined as a length of stay of <2 midnights. We queried our prospectively collected arthroplasty database and compared demographics, comorbidities, surgical indication, type of procedure, discharge disposition, readmissions, and complications between the outpatient and inpatient groups. RESULTS: There were only 166 revision patients (16%) who met outpatient criteria. Revision THA outpatients were more likely to have a head and liner exchange (49% vs 25%, P < .001) and an indication of instability (93% vs 44%, P < .001). Revision TKA outpatients were more likely to have an isolated liner exchange (34% vs 14%, P < .001) and have an indication of instability (67% vs 25%, P < .001). Patients undergoing a revision for infection and aseptic loosening were more likely to require an inpatient stay than other revision indication (P < .05). CONCLUSION: The vast majority of revision TKA and THA patients met CMS inpatient criteria. In addition to a projected decrease in facility reimbursement, concerns exist for the safety of early discharge and access to care for these complex patients if CMS removes all revisions from the Inpatient Only list.