Reverse and total shoulder arthroplasty among Medicare patients in the ambulatory surgery center: a matched cohort study and retrospective review of 90-day complications

Background

Studies have shown the safety of outpatient total shoulder arthroplasty (TSA) in ambulatory surgery centers (ASCs), but none have specifically examined Medicare patients. Until recently, all TSAs among Medicare patients were required to be completed in a hospital as no ASC code (Current Procedural Terminology 23472) existed. The purpose of this study was to compare the intraoperative and 90-day episode of care complications among Medicare patients undergoing reverse total shoulder arthroplasty (rTSA) or anatomic total shoulder arthroplasty (aTSA) at a freestanding ambulatory surgery center to those of Medicare patients undergoing TSA as hospital inpatients (INPTs) or at a freestanding surgery center with commercial insurance. Our hypothesis was no difference between cohorts would be seen.

Methods

Our institution’s records were queried for all patients undergoing rTSA or aTSA from 2018 through 2022 who completed 90-day follow-up. Three cohorts were identified: all Medicare patients undergoing TSA in an ASC, an age and American Society of Anesthesiologists score best match 1:1 cohort of Medicare patients undergoing shoulder arthroplasty in the hospital, and all privately insured patients undergoing TSA in an ASC. A total of 395 patients met inclusion for analysis. Surgical complications, postoperative complications, hospital (re)admissions, and revisions were identified.

Results

The mean age was significantly older in the Medicare ASC cohort (mean 72.79 years) and Medicare INPT cohort (73.01y) compared with the privately insured ASC cohort (59.45 y). Overall, 33 (8.4%) complications, three revisions and four (re)admissions occurred within 90 days. There was one urgent hospital transfer in the privately insured ASC cohort. The overall complication rates for each group were not significantly different: 10.0% for Medicare ASC, 11.1% for Medicare INPTs, and 6.5% for privately insured ASC (P value = .339). The risk ratio (RR) for incidence of within 90-day postoperative complications was not significantly different amongst the cohorts. The RR for Medicare ASC patients was 0.9 compared with Medicare INPTs, and 1.53 compared with privately insured ASC patients. The RR for ASC patients (Medicare and privately insured) was 0.68 compared with Medicare INPTs. There was no significant increase in risk of complications among the Medicare ASC patients compared with either cohort regardless of surgical age, sex, body mass index, or American Society of Anesthesiologists score.

Conclusion

Medicare ASC patients undergoing rTSA or aTSA had a similar postoperative complication RR compared with Medicare INPTs and commercially insured ASC patients. Our findings suggest that TSA can be performed safely in freestanding ASCs on appropriately selected Medicare patients.