The Timing of Corticosteroid Injections After Arthroscopic Shoulder Procedures Affects Postoperative Infection Risk.

BACKGROUND: Corticosteroid injections are sometimes used in the postoperative period after shoulder arthroscopy; however, a well-defined safety profile has not been established.

PURPOSE: To examine the association between the timing of postoperative corticosteroid injections and rates of infection after shoulder arthroscopy.

STUDY DESIGN: Cohort study; Level of evidence, 3.

METHODS: Private payer and Medicare national insurance databases were queried for patients who underwent arthroscopic rotator cuff repair, debridement, or subacromial decompression. Patients who underwent corticosteroid injections within 1, 2, 3, or 4 months postoperatively were identified and compared with a matched control group that underwent the same procedures without a postoperative steroid injection. International Classification of Diseases, Ninth Revision, and Current Procedural Terminology codes were used to identify rates of postoperative infection within 90 days after injection for the study groups and controls. Multivariate binomial logistic regression analysis was used to compare groups, and adjusted odds ratios (ORs) and 95% CIs were calculated, with P < .05 considered significant.

RESULTS: A total of 3946 patients were identified, including 264 patients who received an injection within 1 month after surgery, 471 within 2 months, 1037 within 3 months, 1874 within 4 months, and 2640 matched controls. When compared with controls, patients who underwent a corticosteroid injection within 1 month postoperatively had a significantly higher rate of infection (private payer: OR, 2.63; P = .014; Medicare: OR, 11.2; P < .0001). There were no differences in infection rates at all other time points ( P = .264-.835).

CONCLUSION: This study adds to the evidence suggesting caution when administering injections in the immediate postoperative period after shoulder arthroscopy. Although causality cannot be determined on the basis of this database review, the authors found a significant association between intra-articular corticosteroid injections administered 1 month postoperatively and an increased rate of postoperative infection in Medicare and private payer patient cohorts as compared with a control group.