Recent Increases in Outpatient Total Hip Arthroplasty Have Not Increased Early Complications

Background: Outpatient total hip arthroplasty (THA) has increased in recent years. Recent regulatory changes may allow and incentivize outpatient THA in more patients; however, there are concerns regarding safety. The purpose of this study is to assess early complications in outpatient THA compared to longer hospitalization. Methods: We identified patients undergoing primary THA in the National Surgical Quality Improvement Program database between 2015 and 2018. Patients were stratified by length of stay (LOS): 0 days (LOS 0), 1-2 days, and ≥3 days. Thirty-day rates of any complication, wound complications, readmissions, and reoperation were assessed. Multivariate analysis was performed. Results: In total, 4813 (4%) patients underwent outpatient THA, 84,627 (64%) had LOS of 1-2 days, and 42,293 (32%) had LOS ≥3 days. LOS 0 patients were younger, had lower body mass index, and less medical comorbidities compared to those with postsurgical hospitalization. Any complication was experienced in 3.2% of the LOS 0 group, 5.3% of the LOS 1-2 group, and 15.6% for the LOS ≥3 group (P < .0001). Readmission rates were 1.6%, 2.6%, and 4.7% for the 3 groups, respectively (P < .0001). After controlling for confounding variables, patients with LOS 1-2 days had higher odds for any complication (odds ratio 1.56 [1.32-1.83) and readmission (odds ratio 1.41 [1.12-1.78]) compared to LOS 0 days. Patients with LOS ≥3 days had higher odds for complications compared to LOS 0 or 1-2 days. Conclusion: Outpatient THA had lower odds for readmission or complications compared to LOS 1-2 days. Despite increased outpatient surgery, many patients had postsurgical hospitalization and, due to patient factors, this remains an integral patient of post-THA care.