The Outpatient Surge in Total Hip Arthroplasty: National Trends in Volume Migration, Demographic Disparities, and Comorbidity Profiles (2019-2022)

Background: Total hip arthroplasty (THA) continues to shift from inpatient to outpatient facilities. Purpose: We sought to examine trends in THA settings, demographic differences, and comorbidity variations to inform patient selection, outcomes, and policy. Methods: We performed a retrospective study using data from January 1, 2019, to December 31, 2022, which we obtained from the Nationwide Inpatient Sample database and Nationwide Ambulatory Surgery Sample, from the U.S. Agency for Healthcare Research and Quality. Patients undergoing primary, elective THA were identified. Results: Of the 1 449 639 patients we identified who underwent elective THA, 843 824 underwent the procedure in a hospital-owned ambulatory facility and 605 815 in a hospital (inpatient setting). A total of 86% of THA volume migrated to outpatient centers from 2019 to 2022. Patients who underwent THA at an outpatient facility versus an inpatient setting were younger (65.3 vs 66.3 years). A higher percentage of female versus male patients had surgery in a hospital than in an outpatient center (56.2% vs 53.8%). White and black patients were more likely to be treated at an inpatient facility, whereas Hispanic patients were more likely to be treated at an outpatient facility. Medicare and Medicaid patients were more likely to undergo surgery as inpatients. Patients with medical comorbidities, as well as smokers and patients with opioid use disorder, were overwhelmingly more likely to undergo inpatient THA. Conclusion: This retrospective database analysis found that from 2019 through 2022, outpatient THA numbers increased each year, with 90% of THAs being performed in hospital-owned ambulatory facilities in 2022. Patients with significant medical comorbidities and Medicare/Medicaid insurance, as well as white and black patients, were more likely to have inpatient surgery. Level of Evidence: Level III, Retrospective Database Study.