The impact of prior ipsilateral arthroscopy on infection rates after shoulder arthroplasty.

Background: Patients frequently undergo interventions before shoulder arthroplasty, including injections and arthroscopy. Although the potential impact of injections on postoperative outcomes such as infection has been well studied, it is less clear whether prior arthroscopy has an impact on infection rates after shoulder arthroplasty. The purpose of this study was to determine whether prior ipsilateral shoulder arthroscopy is associated with an increased risk of postoperative infection after shoulder arthroplasty.
Methods: Patients who underwent shoulder arthroplasty, including hemiarthroplasty, total shoulder arthroplasty, or reverse shoulder arthroplasty with a minimum of 1-year preoperative database exposure, were queried using Current Procedural Terminology codes from 2 large insurance databases, including both private-payer (Humana, 2008-2017) and Medicare (2006-2014) data. Patients with procedures for infection, fractures, or without laterality data were excluded. Those who underwent ipsilateral shoulder arthroscopy within 2 years before their arthroplasty were identified and compared with controls who did not undergo prior arthroscopy. Each database was analyzed separately. Periprosthetic infection within 1 year after arthroplasty was queried for each group and compared using a logistic regression analysis with control for demographic and comorbidity confounders.
Results: A total of 9362 Medicare patients and 17,716 private-payer patients were included in the study. Of these, 486 (5.2%) Medicare patients and 685 (3.9%) private-payer patients underwent prior arthroscopy. In the Medicare database, prior arthroscopy was also associated with a postarthroplasty infection rate of 3.9% as compared with 1.9% in the control group (odds ratio: 1.96, 95% confidence interval: 1.20-3.22, P = .003). Similarly, in the private insurance cohort, prior shoulder arthroscopy was associated with a postarthroplasty infection rate of 2.9% as compared with 1.4% in the control group (odds ratio: 1.85, 95% confidence interval: 1.13-3.03, P = .005).
Conclusion: Shoulder arthroscopy performed within 2 years before shoulder arthroplasty is associated with a higher infection rate in the first year after shoulder arthroplasty.
(Copyright © 2020 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)