Ambulatory Surgery Centers Versus Hospital Outpatient Departments for Orthopaedic Surgeries

Kevin Y. Wang, BA; Varun Puvanesarajah, MD; Majd Marrache, MD; James R. Ficke, MD; Joseph F. Levy, PhD; Amit Jain, MD


J Am Acad Orthop Surg. 2022;30(5):207-214. 

In This Article

Abstract and Introduction


Background: The goals of this study were to compare the utilization and costs of ambulatory surgery centers (ASCs) versus hospital outpatient department (HOPD) for commonly performed outpatient orthopaedic surgical procedures.

Methods: Commercially insured patients undergoing elective, outpatient orthopaedic surgery were queried using an administrative claims database. We queried the following surgeries: carpal tunnel release, lumbar microdiskectomy, anterior cruciate ligament reconstruction, knee arthroscopy, arthroscopic rotator cuff repair, and bunion repair. Total costs were defined as the sum of all payments for a surgical episode. Professional fees were defined as payments to the primary orthopaedic surgeon and technical fees as all other payments. Comparisons between ASC and HOPD reimbursements were conducted using bivariate statistics and generalized linear models controlling for patient age, sex, and Elixhauser comorbidity index.

Results: Among 990,980 cases of outpatient orthopaedic surgery done from 2013 to 2018, the utilization rate of ASCs increased from 31% to 34% across all procedures assessed: compound annual growth rate of 3.3% for lumbar microdiscectomy, 1.8% for knee arthroscopy, 1.4% for anterior cruciate ligament, 1.4% for carpal tunnel release, 1.2% for arthroscopic rotator cuff repair, and 0.5% for bunion repair (P < 0.001 for all). The average total costs were 26% lower at ASCs than HOPDs (P < 0.001 for each procedure). The average technical fees were 33% lower at ASCs than HOPDs (P < 0.001 for each procedure). Both total costs and technical fees were less for ASCs than HOPDs after controlling for patient age, sex, and Elixhauser comorbidity index (P < 0.001 for each procedure). Over the study period, the mean total costs at HOPDs increased by 2.5% yearly, whereas the mean total costs at ASCs decreased by 0.1% yearly. The average surgeon professional fees declined in both care settings over time.

Conclusion: From 2013 to 2018, there was an increase in ASC utilization for common outpatient orthopaedic surgeries. ASCs were overall less costly than HOPDs for outpatient orthopaedic surgeries.

Level of Evidence: IV


A 2017 report from the Centers for Medicare and Medicaid Services (CMS) estimated that nearly 70% of all surgeries in the United States are done in the outpatient setting, with the fields of orthopaedic surgery, ophthalmology, plastic surgery, and otolaryngology accounting for most of these procedures.[1] CMS recently announced that starting 2022, it will eliminate a number of procedures from "inpatient-only lists" and will allow for them to be done at an ambulatory surgery center (ASC).[2] ASCs have been reported to complement hospital outpatient departments (HOPDs) in providing outpatient surgical services with high standards of safety for a variety of patient groups.[3–6]

Existing literature indicates that ASCs can operate at lower costs than HOPDs, and increased ASC utilization may be a strategy for healthcare cost containment.[7,8] For orthopaedic hand procedures, microdisckectomy, and joint arthroplasty, there has been evidence that ASCs provide equivalent outcomes while reducing costs compared with hospital-based settings.[9–11] In fact, one analysis found that transitioning care from HOPDs to ASCs because of differential payment policies could save CMS more than $57.6 billion over the next decade.[12] Furthermore, some authors have asserted that ASCs provide needed competition, and the payment differences between ASCs and HOPDs in a competitive outpatient surgery market may drive down overall prices for outpatient surgical care.[13] Despite orthopaedic surgeries being commonly done in both ASC and HOPD settings, to the best of our knowledge, a comprehensive analysis comparing ASC versus HOPD utilization for ambulatory orthopaedic surgeries has not been done.

The goals of this study were to (1) analyze trends in ASC versus HOPD utilization for common outpatient orthopaedic procedures and (2) compare costs of orthopaedic surgeries done at ASC versus HOPD in the United States. We focused on the following common procedures: open carpal tunnel release (CTR), lumbar microdiskectomy (LMD), anterior cruciate ligament reconstruction (ACL), knee arthroscopy (KA), arthroscopic rotator cuff repair (RCR), and bunion repair (BR). We hypothesized that over time, outpatient surgical care has shifted from HOPD to an ASC setting, and ASCs may be a lower-cost care site for outpatient orthopaedic surgeries.