Pre-operative corticosteroid injections are associated with a dose-dependent risk for complications following anatomic and reverse total shoulderarthroplasty

Corticosteroid injections (CSIs) are widely used for symptomatic relief in shoulder arthritis, yet concerns persist regarding their impact on post-operative outcomes following shoulder arthroplasty. This study evaluates the dose-dependent relationship between pre-operative CSIs and post-operative complications in patients undergoing anatomic or reverse total shoulder arthroplasty (TSA). Using the PearlDiver insurance claims database (2010-2022), we identified patients undergoing TSA with at least one CSI in the preceding 5 years compared to those without any prior history of CSI. Patients were stratified by the number of pre-operative CSIs (no CSI, 1-2, 3-4, 5+) and matched by baseline demographics. Surgical and medical complications were assessed at 90 days, 1 year, and 5 years post-operatively, with 5 year surgical complications being the primary outcome of interest. Of 124,144 patients, increased CSIs were associated with progressively higher rates of surgical complications. At 1 year, rates of revision, post-operative stiffness, cuff disease, and nerve injury showed a stepwise increase in complications with each additional CSI given. Receiving 5 or more CSIs before shoulder arthroplasty was associated with higher rates of revision at 5 years (odds ratio [OR]: 1.60, confidence interval [CI]: 1.10-2.34, number needed to harm: 71.4) and post-operative stiffness at 1 year (OR: 1.24, CI: 1.03-1.48) and 5 years (OR: 1.27, CI: 1.07-1.51) compared with matched patients receiving no CSIs. For every additional CSI given pre-operatively, there was a statistically significant compounding 2.03% increased risk of revision surgery within 5 years in the unmatched cohort and a statistically significant compounding 2.67% increased risk of new-onset rotator cuff disease within 5 years in the matched cohort. A dose-dependent relationship exists between pre-operative CSIs and post-operative complications following TSA. An increasing number of injections were correlated with higher risks of prosthetic loosening, stiffness, revision surgery, and new rotator cuff disease, suggesting reason for cautious use of CSIs. Additional work would be required to see if this relationship is causal.