A double-blind randomized controlled trial comparing the effects of subacromial injection with corticosteroid versus NSAID in patients with shoulder impingement syndrome

Hypothesis: The objective of this study was to compare the efficacy of subacromial injection of triamcinolone compared to injection of ketorolac in the treatment of external shoulder impingement syndrome. Methods: Thirty-two patients diagnosed with external shoulder impingement syndrome were included in this double-blinded randomized controlled clinical trial. Each patient was randomized into the steroid group or nonsteroidal anti-inflammatory drugs (NSAID) group. The steroid syringe contained 40 mg triamcinolone; and the NSAID syringe contained 60 mg ketorolac. Each patient was evaluated in terms of arc of motion, visual analog scale (VAS) for evaluating pain, and the UCLA (The University of California at Los Angeles) shoulder rating scale. Results: At 1 month follow-up, both treatment arms resulted in increased range of motion and decreased pain. The steroid group decreased in active abduction while the NSAID group increased (steroid: 134°, NSAID: 151°, P = .03). The mean improvement in the UCLA shoulder rating scale at 4 weeks was 7.15 for the NSAID group and 2.13 for the steroid group (P = .03). Subgroup analysis of the UCLA scale demonstrated an increase in both forward flexion strength (P = .04) and patient satisfaction (P = .03) in the NSAID group. No significant difference could be seen in all other outcome measures. Conclusion: In this study, an injection of ketorolac resulted in greater improvements in the UCLA shoulder rating scale than an injection of triamcinolone at 4 weeks follow-up. While both triamcinolone and ketorolac are effective in the treatment of isolated subacromial impingement, ketorolac appears to have equivalent if not superior efficacy; all the while decreasing patient exposure to the potential side-effects of corticosteroids.