Study: Hospital same‑day knee replacements match ASC outcomes, even in higher‑risk patients

Editor's Note

A recent Duke University analysis challenges the long‑held assumption that ambulatory surgery centers (ASCs) inherently deliver superior results for outpatient joint replacement, Orthopedics This Week March 18 reports. In the February 2025 Journal of Arthroplasty, researchers report that same‑day discharge total knee arthroplasty (TKA) performed in a tertiary‑care hospital achieved outcomes comparable to those in a freestanding ASC—even though hospital patients were older, sicker, or faced social barriers that excluded them from ASC eligibility.

The retrospective study, led by senior author Sean Ryan, MD, and corresponding author Michael P. Bolognesi, MD, chief of adult reconstruction at Duke, reviewed 449 primary TKAs carried out between August 2021 and January 2024. Surgeons and patients jointly chose the surgical venue; strict medical and social criteria governed ASC candidacy. In a nutshell:

• Patient mix. 63.3% (284 cases) occurred at Duke’s ASC, while 36.7% (165 cases) were completed in the university hospital. Nearly 94% of hospital patients triggered at least one ASC exclusion criterion—ranging from significant comorbidities to inadequate home support.
• Key finding. Despite this more complex cohort, the hospital group posted complication, readmission, and reoperation rates statistically indistinguishable from the ASC group, while still meeting same‑day discharge targets.
• Program roots. Duke began building its hospital‑based same‑day pathway before the COVID‑19 pandemic and expanded it sharply during the crisis, honing perioperative protocols, patient education, and rapid‑recovery anesthesia techniques.

“The assumption has always been that results are inherently better at the ASC based on patient selection,” Dr Bolognesi told Orthopedics This Week. “We worked hard to develop a same‑day discharge program at our main hospital, and this study shows you don’t have to abandon the concept for higher‑risk patients.”

For orthopedic surgeons, the message is pragmatic: leverage both settings. The authors stress their findings are not a repudiation of outpatient migration—multiple studies confirm ASCs are safe and cost‑effective for carefully screened candidates. Rather, the data support maintaining a hospital option for individuals whose medical complexity or social circumstances make an ASC inappropriate, without sacrificing quality.