Introduction:Migration of total knee arthroplasty (TKA) procedures from the inpatient setting to outpatient venues, especially freestanding ambulatory surgery centers (ASCs), requires the use of reliable patient selection algorithms and standardized perioperative pathways to facilitate favorable outcomes for patients.Methods:This retrospective chart review included consecutive TKA procedures performed over a 5-year period between January 2014 and January 2019 at 2 freestanding ASCs. The patient selection algorithm was developed on the basis of patient comorbidities to minimize the potential for adverse events. All procedures were performed by one of eight orthopedic surgeons who were identified a priori as adhering to similar multimodal pain management regimens, including the use of spinal anesthesia, general or monitored-care anesthesia, adductor canal blocks, pericapsular injection of liposomal bupivacaine, nonsteroidal anti-inflammatory drugs, gabapentin, tramadol, acetaminophen, and oxycodone on an as-needed basis. Outcomes, including surgical complications, healthcare resource utilization (HCRU), and patient satisfaction, were measured before discharge and at a 90-day follow-up visit.Results:Four hundred thirty-nine TKA procedures in 386 patients were identified for inclusion. Of these patients, 115 (29.8%) were performed in patients with the American Society of Anesthesiologists physical status IIIa. Mean (standard deviation) length of stay at the ASC was 500 (107) minutes, including 136 (47) minutes of surgery and 201 (78) minutes to ambulation. The overall rates of surgical complications and 90-day hospital admissions were low (1.4% and 0.7%, respectively), as was the need for additional HCRU, including additional surgical procedures related to index surgery, emergency department visits, and unplanned clinic visits or calls. At the 90-day follow-up visit, 96% of patients reported being pleased with their outcomes.Discussion:With careful patient selection, standardized perioperative pathways, and multimodal analgesia protocols, TKA procedures can be performed in the ASC setting with low complication rates, minimal postdischarge HCRU, and high rates of patient satisfaction.Level of evidence:III