The incidence of shoulder arthroplasty infection presents a substantial economic burden in the United States: a predictive model.

Background: Periprosthetic joint infections (PJIs) are a major cause of morbidity after shoulder arthroplasty. Prior national database studies have estimated the trends of shoulder PJI up to 2012. Since 2012, the landscape of shoulder arthroplasty has changed drastically with the expanding popularity of reverse total shoulder arthroplasty. The dramatic growth in primary shoulder arthroplasties is likely paralleled with an increase of PJI case volume. The purpose of this study is to quantify the rise in shoulder PJIs and the economic stress they currently place on the American healthcare system as well as the toll they will incur over the coming decade.

Methods: The Nationwide Inpatient Sample database was queried for primary and revision anatomic total shoulder arthroplasty, reverse total shoulder arthroplasty, and hemiarthroplasty from 2011-2018. Multivariate regression was used to predict cases and charges through the year 2030 adjusted to 2021 purchasing power parity.

Results: From 2011 to 2018, PJI was found to be 1.1% shoulder arthroplasties, from 0.8% (2011) to 1.4% (2018). Anatomic total shoulder arthroplasty experienced the greatest proportion of infections at 2.0%, followed by hemiarthroplasty at 1.0% and reverse total shoulder arthroplasty at 0.3%. Total hospital charges grew 324%, from $44.8 million (2011) to $190.3 million (2018). Our regression model projects 176% growth in cases and 141% growth in annual charges by 2030.

Conclusion: This study demonstrates the large economic burden that shoulder PJIs pose on the American healthcare system, which is predicted to reach nearly $500 million in charges annually by 2030. Understanding trends in procedure volume and hospital charges will be critical in evaluating strategies to reduce shoulder PJIs.