Outpatient Total Hip Arthroplasty in the United States: A Population-based Comparative Analysis of Complication Rates.

INTRODUCTION: With healthcare expenditure in the national forefront, outpatient arthroplasty is an appealing option in select patient populations. The purpose of this study was to determine the complication rates associated with outpatient total hip arthroplasty (THA) in comparison to standard inpatient THA.

METHODS: We performed a retrospective review of the Humana subset of the PearlDiver insurance records database to identify patients undergoing THA (Current Procedural Terminology-27130 and Current Procedural Terminology-27132) as either outpatients or inpatients from 2007 to 2016. Multivariate logistic regression adjusting for age, gender, and Charlson Comorbidity Index were used to calculate odds ratios of complications among outpatients undergoing THA relative to inpatients undergoing THA.

RESULTS: The query identified 2,184 patients who underwent outpatient THA and 73,596 patients who underwent inpatient THA. The median age was in the 65 to 69 age group and in the 70 to 74 age group for the outpatient and inpatient cohorts, respectively (P < 0.001). Outpatients undergoing THA had a significantly lower incidence of comorbid hypertension (P < 0.001), cerebrovascular disease (P = 0.001), obesity (P = 0.017), chronic obstructive pulmonary disorder (P = 0.045), and chronic kidney disease (P = 0.049). The incidence of both outpatient THA (P = 0.001) and inpatient THA (P < 0.001) increased over the study period. After adjusting for age, gender, and Charlson Comorbidity Index, patients undergoing outpatient THA had comparable rates of all queried surgical complications, including component revision, irrigation and debridement, and hip dislocation at 1 year. Rates of postoperative medical complications were also comparable between the two cohorts.

CONCLUSION: Outpatient THA is increasing in frequency nationwide and has comparable postoperative complication rates. With its potential to minimize arthroplasty care costs, outpatient THA is a safe and effective option among appropriately selected patients.