High comorbidity burden and low incidence of adverse events in primary shoulder arthroplasty in tertiary care at a university hospital.

Background: Reducing perioperative risk is in the focus of primary arthroplasty caregivers. Primary shoulder arthroplasty patients are considered among those with the lowest perioperative risk. Nonetheless, in tertiary care centres and university settings patients with significant comorbidities are being treated. It remains unclear whether the overall comorbidity burden is truly higher and if this results in an increased frequency of adverse events (AE). As a result, we conducted a study to assess the comorbidity burden and the frequency of major perioperative adverse events and predictive factors following primary shoulder arthroplasty in the university setting. Methods: A retrospective cohort analysis was conducted on patients undergoing primary shoulder arthroplasty for a non-trauma, non-tumour indication from January 1st, 2014 through December 31st, 2018. Administrative data were recorded to assess comorbidity burden and revision surgery within the first postoperative year. Major adverse events were routinely recorded on a weekly basis by the treating physicians. Descriptive and comparative statistical analyses were performed. The cohort was compared against a large North American sample. Results: Of 386 patients who underwent 400 primary shoulder arthroplasties 14 (3.5 %) experienced adverse events. While AE were distributed equally among anatomical and reverse shoulder arthroplasties, no adverse event was recorded in the 34 hemiarthroplasty patients. The cohort showed an increased comorbidity burden in international comparison. Peptic ulcer disease was significantly associated with AE, while mild liver disease experienced a trend towards AE. Conclusion: We found an increased comorbidity burden and a low rate of AE for primary shoulder arthroplasty in a tertiary care and university setting. The distinct role of peptic ulcer disease in this cohort and the trend in mild liver disease merit further investigation in larger samples. The findings underscore the importance of perioperative risk assessment and management. Level of evidence: III, retrospective cohort study.