Immediate Pain Relief at Time of Corticosteroid Injection for Idiopathic Adhesive Capsulitis as a Predictor of Eventual Outcomes

Abstract

Background: Corticosteroid injection and physical therapy remain the mainstay of treatment for idiopathic adhesive capsulitis of the shoulder; however, a certain percentage of patients will not improve using these interventions and will require manipulation under anesthesia (MUA) and/or lysis of adhesions (LOA). Purpose: To evaluate whether the immediate pain reduction after fluoroscopic-guided, mixed anesthetic-corticosteroid injection for idiopathic adhesive capsulitis is related to the eventual need for LOA/MUA or a repeat glenohumeral steroid injection. Study Design: Case-control study; Level of evidence, 3. Methods: This single-institution study involved patients undergoing fluoroscopic glenohumeral corticosteroid injection for a diagnosis of idiopathic adhesive capsulitis between 2010 and 2017. Included were patients with a minimum of 1-year postinjection follow-up and visual analog scale (VAS) pain scores from immediately before and after the injection. The primary analysis was the relationship between patients with an immediate change in VAS score after injection and those who underwent LOA/MUA. A repeat glenohumeral injection was also evaluated as an outcome. Receiver operator characteristic curves and a multivariate binomial logistic regression analysis were performed. Results: Overall, 739 shoulders in 728 patients (mean age, 52.6 years; 68% women) were included, of which 38 (5.1%) underwent LOA/MUA and 209 (28%) underwent repeat injections. The immediate change in the VAS score was not significantly associated with the eventual need for LOA/MUA. Preinjection VAS and immediate postinjection VAS scores were not significant predictors of eventual LOA/MUA or subsequent injection. For all 3 predictors, the area under the receiver operator characteristic curve classified them as extremely poor discriminators. Conclusion: The immediate pain response to a fluoroscopic-guided glenohumeral injection for idiopathic shoulder adhesive capsulitis was not predictive of the eventual need for LOA/MUA or subsequent injection. Patients can be counseled that even if their initial pain response to an injection is poor, they still have an excellent chance of avoiding surgery, as the overall rate of LOA/MUA was low (5.1%).