Prior Bariatric Surgery is Associated with an Increased Rate of Complications after Primary Shoulder Arthroplasty Independent of Body Mass Index.

INTRODUCTION: Bariatric surgery (BS) is a debated, yet commonly used management strategy in the treatment of morbidly obese patients. Despite recent advances in BS techniques, there is limited data on the potential impact of prior BS in patients undergoing shoulder arthroplasty. This investigation evaluated the outcomes of primary shoulder arthroplasty (SA) in patients with prior BS when compared to matched controls.

METHODS: Over a 31-year period (1989 - 2020), 183 primary SA (12 hemiarthroplasties [HA], 59 anatomic total shoulder arthroplasties [aTSA], and 112 reverse shoulder arthroplasties [rTSA]) in patients with prior BS and a minimum of 2-year follow-up had been performed at a single institution. This cohort was matched 1:1:1 according to age, sex, diagnosis, implant, American Society of Anesthesiologists score, Charlson Comorbidity Index, and SA surgical year to separate control groups of SA with no history of BS and a BMI of either < 40 kg/m2 (Low BMI group) or ≥ 40 kg/m2 (High BMI group). Surgical complications, medical complications, reoperations, revisions, and implant survivorship were assessed. The mean follow-up time was 6.8 years (range, 2 to 21 years).

RESULTS: The bariatric surgery cohort had a higher rate of any complication (29.5% vs. 14.8% vs. 14.2%; P < .001), surgical complications (25.1% vs. 12.6% vs. 12.6%; P = .002), and non-infectious complications (20.2% vs. 10.4% vs. 9.8%; Low P = .009 and High P = .005) relative to both low and high BMI groups. For BS patients, the 15-year survivorship free of any complication was 55.6 (95% confidence interval [CI], 43.8% - 70.5%) compared to 80.3% (95% CI, 72.3% - 89.3%) in the low BMI group and 75.8% (65.6% - 87.7%) in the high BMI group (P < .001). Comparisons of the bariatric and matched groups demonstrated no statistical differences between the risk of reoperation or revision surgery. When SA was performed within 2 years of BS, higher rates of complications (50% vs. 27.0%; P = .030), reoperations (35.0% vs. 8.0%; P = .002), and revisions (30.0% vs. 5.5%; P = .002) were observed.

CONCLUSIONS: Primary shoulder arthroplasty in patients with prior bariatric surgery demonstrated an elevated complication profile when compared to matched cohorts of patients with no history of BS and either low or high BMI. These risks were more pronounced when shoulder arthroplasty was performed within 2 years of bariatric surgery. Care teams should be aware of the potential implications of the post-bariatric metabolic state and investigate whether further perioperative optimization is warranted.