Comparison of High- and Low-Dose Corticosteroid in Subacromial Injection for Periarticular Shoulder Disorder: A Randomized, Triple-Blind, Placebo-Controlled Trial

Objective: To determine whether subacromial injection with high-dose corticosteroid in patients with periarticular shoulder disorders is better than low-dose corticosteroid or placebo in improving pain, function, and active range of motion (AROM). Design: Multicenter, randomized, triple-blind, placebo-controlled trial. Setting: Primary (n=2) and university-affiliated (n=1) tertiary-care hospitals. Participants: Volunteers (N=79) with periarticular shoulder disorders with at least 1 month's duration of pain. Intervention: Participants were randomly assigned to receive ultrasound-guided subacromial injection with triamcinolone acetonide, 40 or 20mg, or placebo. After a single injection, participants were followed up for 8 weeks. Main Outcome Measures: Visual analog scale (VAS) of average shoulder pain level during the past I week, Shoulder Disability Questionnaire (SDQ), and angles of shoulder AROM (including flexion, abduction, external rotation, internal rotation) pre- and posttreatment at weeks 2, 4, and 8. Results: There were no significant differences among the 3 groups (triamcinolone acetonide, 40mg, group 1, n=27; triamcinolone acetonide, 20mg, group 2, n=25; placebo, group 3, n=27) in terms of demographic and clinical characteristics at baseline. (1) Within-group comparison: VAS score, SDQ score, and AROM for groups 1 and 2 significantly improved at weeks 2, 4, and 8 (P<.0167). However, there was no difference in VAS score, SDQ score, and AROM scores for group 3. (2) Between-group comparison: significant differences in VAS score, SDQ score, and abduction, external rotation, and internal rotation of AROM were shown between groups 1 and 2 and group 3 at weeks 2, 4, and 8 (P<.05). Conclusions: This was the first study to assess the efficacy of corticosteroid according to 2 different doses, which are the most widely used in subacromial injection for participants with periarticular shoulder disorders. This study showed no significant differences between the high- (triamcinolone acetonide, 40mg) and low-dose (20mg) corticosteroid groups, indicating preferred use of a low dose at the initial stage.