Outpatient Total Hip and Knee Arthroplasty at an Academic Ambulatory Surgery Center: A Retrospective Review of the First 500 Cases

Introduction: In September 2022, an ambulatory orthopaedic surgery center affiliated with a tertiary academic medical center began performing outpatient total hip arthroplasty and total knee arthroplasty. Patients were selected using a predefined screening algorithm designed to identify candidates appropriate for discharge within 23 hours. After an initial review of the first 100 cases demonstrated high rates of protocol adherence and safe discharge, we evaluated the first 500 consecutive patients to assess screening compliance, discharge outcomes, and postoperative complications. Methods: A retrospective review was performed of 500 patients (255 total hip arthroplasties, 245 total knee arthroplasties) treated between September 2022 and August 2023. Screening accuracy, discharge timing, and emergency department visits or hospital admissions within 90 days were recorded through comprehensive electronic medical record review. Results: Of the 500 patients screened, 89% (n=445) of patients met screening criteria appropriately. Despite this, 98.8% (n=494) were discharged home on the day of surgery and 99.6% (n=498) were discharged within 23 hours. 1.2% (n=6) of patients required either overnight observation or transfer to the main hospital. Within 90 days, 9% (n=45) of patients had at least one emergency department visit or hospital admission. Major complications were infrequent and included prosthetic dislocation (n=2), venous thromboembolism (n=3), prosthetic joint infection (n=1), and periprosthetic fracture (n=1). Discussion: Outpatient total joint arthroplasty at an academic ambulatory center demonstrates high rates of successful same-day discharge with low rates of serious complications. Continued use of structured preoperative screening appears to support safe expansion of outpatient total joint arthroplasty.