Comparison of glenohumeral and subacromial steroid injection in primary frozen shoulder: a prospective, randomized short-term comparison study

Abstract

Glenohumeral (GH) joint steroid injection is one of the most well-known treatments for frozen shoulder. However, the low accuracy of GH joint injections and the improvement of symptoms after subacromial (SA) steroid injections led us to design a study that compares the efficacy of a steroid injection for primary frozen shoulder according to the injection site. Patients with primary frozen shoulder were randomly divided into 2 groups according to the location of the injection: a GH group of 37 for the glenohumeral joint and an SA group of 34 for the subacromial space. Injections were completed using ultrasonographic guidance. Evaluations using a visual analog scale (VAS) for pain, the Constant score, and passive range of motion (ROM) were completed at 3, 6, and 12 weeks after the injection. The GH group showed lower pain VAS at 3 weeks, but no statistical difference was found between the 2 groups at 6 and 12 weeks. Improvement in pain was evident at every follow-up visit compared with the preinjection evaluation. There was no significant difference between the 2 groups with respect to the Constant score or ROM at serial follow-up. The GH steroid injection was not superior to a SA injection for patients with primary frozen shoulder even though injection at the GH joint led to earlier pain relief compared with the SA injection. SA steroid injection along with a GH injection is an alternative modality, and the treatment should be individualized and tailored appropriately.