Factors That Increase the Risk of Infection After Elbow Arthroscopy: Analysis of Patient Demographics, Medical Comorbidities, and Steroid Injections in 2,704 Medicare Patients.

PURPOSE: To use a national database to determine (1) the incidence of joint infection after elbow arthroscopy, (2) identify independent patient-related risk factors for infection, and (3) determine the influence of concomitant intra-articular corticosteroid injection on infection risk.

METHODS: The 100% Medicare Standard Analytic Files were queried to identify patients who underwent elbow arthroscopy from 2005 to 2012. Postoperative elbow infections occurring within 6 months of surgery were identified using both International Classification of Diseases, 9th Revision codes for postoperative infection and Current Procedural Terminology codes for the surgical treatment of a postoperative infection. Patients were excluded if their initial arthroscopic procedure was performed for infection. A multivariate binomial logistic regression analysis was then used to evaluate patient-related risk factors for postoperative infection.

RESULTS: Of the 2,704 elbow arthroscopy cases identified, 42 (1.55%) developed a postoperative infection. The annual incidence of infections did not increase significantly over the course of the study (P = .374). A number of patient demographics and medical comorbidities significantly increased the risk of infection. The most notable factors included age ≥ 65 years (odds ratio [OR] 2.38, P = .006), body mass index > 40 (OR 1.97, P = .024), tobacco usage (OR 1.80, P = .046), alcohol usage (OR 4.01, P < .001), diabetes mellitus (OR 2.10, P = .015), inflammatory arthritis (OR 2.81, P < .001), hypercoagulable disorder (OR 2.51, P = .015), and intra-articular corticosteroid injection at the time of arthroscopy (OR 2.79, P = .006).

CONCLUSIONS: The annual number of elbow arthroscopies performed in the United States has increased steadily; however, the postoperative infection rate remained consistently low at 1.55%. There are a number of patient-specific risk factors that increase this risk with OR ranging from 1.97 to 4.01. Similarly, patients who receive an intra-articular corticosteroid injection at the time of surgery are nearly 3 times (OR 2.79) more likely to develop a postoperative infection. LEVEL OF EVIDENCE: Level III, case-control study.