Simplified, single-shot, capsule-preserving hydrodilatation combined with corticosteroids versus isolated corticosteroid injection for adhesive capsulitis: a randomized controlled trial

Glenohumeral corticosteroid injection has been a major treatment for adhesive capsulitis of the shoulder. Hydrodilatation is also a treatment option. However, few studies have considered the combined treatment of the two methods with heterogeneous protocols and results. The purpose of this study is to investigate the additional effect of hydrodilatation for glenohumeral corticosteroid injection in adhesive capsulitis of the shoulder involving a streamlined process. Sixty-two patients were randomized in this randomized controlled trial. Of these, 50 patients were included in the final per-protocol analysis: 24 in group CS and 26 in group CSHD. Group CS received a single ultrasound-guided glenohumeral injection with 1 mL (40 mg) triamcinolone and 4 mL lidocaine. Group CSHD received the same injection with an additional 15 mL of saline. Capsular distension without intended rupture was assessed using ultrasound, and the capsule-humeral head distance was measured. Pain visual analog scale, patient satisfaction, range of motion (ROM) in forward elevation and internal/external rotation, American Shoulder and Elbow Surgeons (ASES) score, and Constant score were assessed before injection and at 3 weeks, 7 weeks, 3 months, and 6 months after injection. The baseline data were similar between the groups. After injection, the CSHD group demonstrated a significantly greater capsule-humeral head distance on ultrasound ( p < 0.001). Significant improvement was demonstrated within each group after 6 months ( p < 0.001 in all parameters). However, compared to group CS, group CSHD showed a greater increase in the ASES score as early as week 3 ( p < 0.001) and in ROM as early as week 7 ( p < 0.050 in all directions). At the last follow-up at 6 months, group CSHD showed significantly better results in ROM ( p < 0.005 in all directions), patient satisfaction ( p = 0.004), ASES ( p = 0.040), and Constant scores ( p = 0.011) than group CS. In treating adhesive capsulitis, adding saline to a conventional corticosteroid injection to perform a single-shot, capsule-preserving hydrodilatation with a 20 mL solution may improve short- to mid-term functional recovery compared to an isolated corticosteroid injection. ClinicalTrials.gov identifier NCT06493656 (Retrospectively registered July 7, 2024).