Outpatient Total Hip Arthroplasty Volume up Nearly 8-Fold After Regulatory Changes With Expanding Demographics and Unchanging Outcomes: A 10-Year Analysis

Abstract

BackgroundWith the removal of total hip arthroplasty (THA) from the inpatient-only (IPO) lists, the orthopedic landscape across the United States has changed rapidly. Thus, this study aimed to: 1) characterize the change in THA volume for outpatient and inpatient surgeries; 2) elucidate demographical differences before and after removal from the IPO list; and 3) analyze 30-day complications, readmissions, and reoperations. MethodsThe National Surgical Quality Improvement Program database was queried for primary THAs between January 2010 and December 2021. The primary outcome was the annual volume of outpatient and inpatient THAs. Secondary outcomes involved 30-day complications, readmissions, and reoperations. The variables between cohorts were analyzed using goodness-of-fit Chi-square tests with summary statistics. ResultsOf the 332,423 THAs between 2010 and 2021, 88% were inpatient THAs (n = 292,974) and 12% were outpatient THAs (n = 39,449). From 2019 to 2021, the volume of inpatient THA decreased by 55% (42,779 to 19,075), while outpatient THA increased by 751% (2,518 to 21,424). Patients who had a THA after 2019 were older (P < .001), more commonly women (P < .001), white (P < .001), and more likely American Society of Anesthesiologists Class III (P < .001). The outpatient cohort had fewer 30-day complications, readmissions, and reoperations. The length of stay for both cohorts decreased until 2019, before increasing in 2020 and 2021 for inpatient THAs, while home discharge and operative time increased for both. ConclusionsThe volume of outpatient THA increased almost eightfold after its removal from the IPO lists in 2020. Despite expanding eligibility with older patients and more comorbidities, 30-day complications, readmissions, and reoperations remain low. These findings support the safe transition to outpatient THA with appropriate patient selection and optimization.