Adverse Events and Their Risk Factors Following Intra-articular Corticosteroid Injections of the Ankle or Subtalar Joint

Background: Little data exists regarding the incidence of adverse events and their associated risk factors following intra-articular corticosteroid injection of the ankle and subtalar joint. The aim of this study was to determine the complication rate associated with such injections and to identify any predictive risk factors. Methods: Adult patients who had received an intra-articular ankle or subtalar joint injection between January 2000 and April 2016 at one of 3 regional hospitals (2 level 1 trauma centers and 1 community hospital) were included. Patients with prior intra-articular injection of corticosteroid into the ankle or subtalar joint were excluded. Explanatory variables were sex, age, race, body mass index, diabetes status, tobacco use, presence of fluoroscopic guidance, location of intra-articular injection, and administering physician's years of experience. Results: Of the 1708 patients included in the final cohort, 99 patients (5.8%) had a total of 104 adverse events within 90 days postinjection. The most prevalent types of adverse events were postinjection flare in 78 patients (4.6% of total cohort, 75% of adverse events) followed by skin reaction in 10 patients (0.6% of total cohort, 9% of adverse events). No infections were noted. Multivariable logistic regression analysis found that intra-articular injection in the subtalar (P = .004) was independently associated with development of an adverse event. Fluoroscopic guidance was not found to be protective of an adverse event compared to nonguided injections (P = .476). Conclusion: The adverse event rate following intra-articular ankle or subtalar joint corticosteroid injection was 5.8%, with postinjection flare being the most common complication. Infections following injection were not reported. Injection into the subtalar joint was independently associated with the development of an adverse event after intra-articular corticosteroid injection, and this was not mitigated by the use of fluoroscopic guidance.