Optimising outcomes of exercise and corticosteroid injection in patients with subacromial pain (impingement) syndrome: a factorial randomised trial

Objectives To compare the clinical effectiveness of (1) physiotherapist-led exercise versus an exercise leaflet, and (2) ultrasound-guided subacromial corticosteroid injection versus unguided injection for pain and function in subacromial pain (formerly impingement) syndrome (SAPS). Methods This was a single-blind 2x2 factorial randomised trial. Adults with SAPS were randomised equally to one of four treatment groups: (1) ultrasound-guided corticosteroid injection and physiotherapist-led exercise, (2) ultrasound-guided corticosteroid injection and an exercise leaflet, (3) unguided corticosteroid injection and physiotherapist-led exercise and (4) unguided corticosteroid injection and an exercise leaflet. The primary outcome was the Shoulder Pain and Disability Index (SPADI), collected at 6 weeks, 6 and 12 months and compared at 6 weeks for the injection interventions and 6 months for the exercise interventions by intention to treat. Results We recruited 256 participants (64 treatment per group). Response rates for the primary outcome were 94% at 6 weeks, 88% at 6 months and 80% at 12 months. Greater improvement in total SPADI score was seen with physiotherapist-led exercise than with the exercise leaflet at 6 months (adjusted mean difference -8.23; 95% CI -14.14 to -2.32). There were no significant differences between the injection groups at 6 weeks (-2.04; -7.29 to 3.22), 6 months (-2.36; -8.16 to 3.44) or 12 months (1.59; -5.54 to 8.72). Conclusions In patients with SAPS, physiotherapist-led exercise leads to greater improvements in pain and function than an exercise leaflet. Ultrasound guidance confers no additional benefit over unguided corticosteroid injection.

Automated summary

In patients with subacromial pain syndrome, physiotherapist-led exercise shows better improvement in pain and function compared to an exercise leaflet. Ultrasound guidance for subacromial corticosteroid injection provides no additional benefit over unguided injection.