Comparison of the efficacy of subacromial injection with sodium bicarbonate versus corticosteroid in patients with chronic subacromial bursitis: a prospective, randomized and controlled study

Objective: Corticosteroid injections have been a widely utilized and well-accepted method of treatment for patients with chronic subacromial bursitis (SAB) who have failed many conservative therapies. As an alternative, we test whether subacromial injection of sodium bicarbonate (SB) can substitute subacromial corticosteroid injection in the treatment for chronic SAB. Methods: 70 patients diagnosed with chronic SAB were divided into two groups randomly. They were treated with SB and triamcinolone (TMC) subacromial injection, respectively. The control (TMC) syringe contained a mixture of 1ml triamcinolone (40 mg), 2 ml of 2% lidocaine and 7 ml of 0.9% saline; and the test (SB) syringe contained a mixture of 2 ml of 2% lidocaine, 6 ml of 5% sodium bicarbonate and 2 ml of 0.9% saline. The visual analog scale (VAS), active range of motion (ROM), and Constant-Murley Score (CMS) of the affected shoulder were respectively completed before and at 1 week, 2 and 4 weeks following the injection. Results: Both groups obtained a significant improvement of VAS, CMS, and active shoulder ROM at 1 week, 2 and 4 weeks follow-up. Pain relief was achieved significantly faster after a steroid injection than after SB injection at 1 week. And there was no significant difference at 2 and 4 weeks following the injection; whereas, no significant difference was found in CMS and active shoulder ROM between the 2 groups at the 4 time points. Conclusion: The efficacy of subacromial SB injection is equivalent to corticosteroid for chronic SAB and may be a potential and useful alternative for the treatment for chronic SAB.