A prospective, double-blind, randomized clinical trial comparing subacromial injection of betamethasone and xylocaine to xylocaine alone in chronic rotator cuff tendinosis.

BACKGROUND: Rotator cuff tendinosis is a common problem with significant health and economic effects. Nonoperative management includes the widespread use of subacromial steroid injections despite the lack of evidence of its efficacy.

HYPOTHESIS: A subacromial injection of betamethasone will be more effective than xylocaine alone in improving the quality of life, impingement sign, and range of motion in patients who have chronic rotator cuff tendinosis or partial rotator cuff tears.

STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1.

METHODS: Patients with rotator cuff tendinosis or partial cuff tear with symptoms longer than 6 months, with failure of 6 weeks of physical therapy and 2 weeks of nonsteroidal anti-inflammatory drugs, who were older than 30 years of age, and who showed >50% improvement with the Neer impingement test were stratified for Workplace Safety and Insurance Board status and previous injection. Outcome measures--the Western Ontario Rotator Cuff Index; American Shoulder and Elbow Surgeons standardized form; Disabilities of the Arm, Shoulder and Hand; active forward elevation; active internal rotation; active external rotation; and the Neer impingement sign--were assessed at 2, 6, 12, and 24 weeks after injection. The injection into the subacromial space contained either 5 mL of 2% xylocaine alone or 4 mL of 2% xylocaine and 1 mL (6 mg) of betamethasone in an opaque syringe.

RESULTS: In 58 patients (betamethasone group, n = 30; xylocaine group, n = 28), the authors found no statistically significant difference between the 2 treatment groups for all outcomes and time intervals. The scores for the Western Ontario Rotator Cuff Index at 3 months were xylocaine = 45.4% +/- 13% and betamethasone = 56.3% +/- 17% (P = .13). At 6 months, the scores were xylocaine = 51% +/- 32% and betamethasone = 59% +/- 26% (P = .38). All other outcomes showed similar values. As well, similar results were found for 2 and 6 weeks after injection. Both groups showed improvement from baseline in all outcomes.

CONCLUSIONS: With the numbers available for this study, the authors found betamethasone to be no more effective in improving the quality of life, range of motion, or impingement sign than xylocaine alone in patients with chronic rotator cuff tendinosis for all follow-up time intervals evaluated.