Prevalence of Shoulder Arthroplasty in the United States and the Increasing Burden of Revision Shoulder Arthroplasty

Background: Existing data on the epidemiology of shoulder arthroplasty are limited to future projections of incidence. However, the prevalence of shoulder arthroplasty (the number of individuals with a shoulder arthroplasty alive at a certain time and its implications for the burden of revision procedures) remains undetermined for the United States. Hence, the purpose of this study was to estimate the prevalence of shoulder arthroplasty in the United States.Methods: The National Inpatient Sample (NIS) was queried to count all patients who underwent total shoulder arthroplasty (TSA), including both anatomic and reverse TSA, and hemiarthroplasty between 1988 and 2017. The counting method was used to calculate the current prevalence of TSA and hemiarthroplasty using age and sex-specific population and mortality data from the U.S. Census Bureau.Results: In 2017, an estimated 823,361 patients (95% confidence interval [CI], 809,267 to 837,129 patients) were living in the United States with a shoulder replacement. This represents a prevalence of 0.258%, increasing markedly from 1995 (0.031%) and 2005 (0.083%). Female patients had a higher prevalence at 0.294% than male patients at 0.221%. Over 2% of people who were >= 80 years of age in the United States were living with a shoulder replacement. Furthermore, approximately 60% of patients living with a shoulder replacement had undergone the operation between 2013 and 2017. The incidence of revision shoulder arthroplasty is increasing on an annual basis, with 10,290 revision procedures performed in 2017, costing the U.S. health-care system $205 million.Conclusions: The prevalence of shoulder arthroplasty in the United States has markedly increased over time. This trend will likely continue given increasing life expectancies and exponentially increasing shoulder arthroplasty incidence rates. Most patients do not have long-term follow-up, and revision shoulder arthroplasty rates are increasing, a trend that is projected to continue. The data from our study highlight the enormous public health impact of shoulder replacement and shed light on a potentially increasing revision burden.