The journal of knee surgery
-
The Centers for Medicaid and Medicare Services (CMS) removed primary total knee arthroplasty (TKA) from the inpatient-only list in January 2018. This study aims to compare outcomes in Medicare-aged patients who underwent primary TKA and had an in-hospital stay spanning less than two-midnights to those with a length of stay greater than or equal to two-midnights. We retrospectively reviewed 4,138 patients ages ≥65 who underwent primary TKA from 2016 to 2020. ⋯ TKA patients classified as outpatient had similar quality metrics and saw similar clinical improvement following TKA with respect to most patient reported outcome measures, although they were demographically different. Outpatient classification is more likely to be assigned to younger males with higher functional scores, lower BMI, CCI, and ASA class compared with inpatients. This Retrospective Cohort Study shows level III evidence.