Intra-articular Corticosteroid Injection versus Suprascapular Nerve Block for Adhesive Capsulitis: A Systematic Review and Meta-analysis of Level I Randomized Controlled Trials.

Background: Intra-articular corticosteroid injection and suprascapular nerve block are both options for nonoperative management of adhesive capsulitis. While numerous studies support the benefits of steroid injections, the use of suprascapular nerve blocks is less established. Published randomized trials comparing steroid injections and suprascapular nerve blocks for managing adhesive capsulitis have reported mixed results.

Purpose: To synthesize the results of published level I studies to compare outcomes for patients with adhesive capsulitis following intra-articular corticosteroid injection or suprascapular nerve block.

Study design: Systematic review and meta-analysis; Level of evidence, 1.

Methods: The study was performed according to the preferred reporting items for systematic reviews and meta-analysis. Three databases were searched for randomized controlled trials comparing an intra-articular steroid injection to a suprascapular nerve block in patients with adhesive capsulitis. Trials were excluded if either group received another procedure or included patients with concomitant ipsilateral shoulder pathology. Outcomes were patient-reported pain intensity and shoulder function, range of motion, and time to symptom resolution. Meta-analysis was performed for pain, shoulder function, and range of motion using random-effects models.

Results: Eight studies with a total of 452 patients were included. Pain was assessed using the shoulder pain and disability index (SPADI) pain subscale and the visual analog scale (VAS). Functional outcomes were assessed using the SPADI and Constant-Murley Score. Range of motion assessments included active and passive movements in abduction, forward flexion, external rotation, and internal rotation. Random-effects comparisons at baseline, 3-4 weeks, 6-7 weeks, and 12 weeks were performed for pain and SPADI scores, and at baseline and 12 weeks for active abduction. Suprascapular nerve blocks were superior to steroid injections for pain at 3-4 weeks (standardized mean difference [SMD]: 0.63, 95% CI: 0.06-1.19, p = 0.03), 6-7 weeks (SMD: 0.49, 95% CI: 0.01-0.96, p = 0.046), and 12 weeks post-intervention (SMD: 1.68, 95% CI: 0.30-3.06, p = 0.017). Nerve blocks were superior to steroid injections in reducing SPADI scores at 12 weeks post-intervention (MD = 8.94, 95% CI: 1.44-16.44 p = 0.020). Nerve blocks were superior to steroid injections for active abduction at 12 weeks post-intervention (MD = 14.44°, 95% CI: 11.05°-17.83°, p < 0.001). Heterogeneity was considerable for all meta-analyses. There were no other significant differences between groups at any time point.

Conclusions: In patients with adhesive capsulitis, suprascapular nerve blocks provide greater pain relief at 3-4, 6-7, and 12 weeks, greater improvements in shoulder function at 12 weeks, and greater active abduction at 12 weeks, compared to intra-articular corticosteroid injections.

Level of evidence: Level I; Systematic Review; Treatment Study.