Treatment of persistent shoulder pain with sodium hyaluronate: a randomized, controlled trial. A multicenter study.
BACKGROUND
Presently, there are no approved nonoperative therapies for the ongoing treatment of persistent shoulder pain. Preliminary data suggest that intra-articular sodium hyaluronate injections may be beneficial for the treatment of persistent shoulder pain resulting from various etiologies. The present study evaluated the efficacy and safety of sodium hyaluronate (Hyalgan; molecular weight, 500 to 730 kDa) for these patients.


METHODS
Six hundred and sixty patients with persistent shoulder pain and limitation resulting from glenohumeral joint osteoarthritis, rotator cuff tear, and/or adhesive capsulitis who had had a failure of conventional therapy were enrolled in this double-blind, randomized, phosphate-buffered saline solution-controlled study, and 456 patients completed twenty-six weeks of follow-up. Patients were randomized to receive either five weekly intra-articular injections of sodium hyaluronate, three weekly intra-articular injections of sodium hyaluronate followed by two weekly intra-articular injections of saline solution, or five weekly intra-articular injections of saline solution. The main outcomes were improvement in terms of shoulder pain on movement at thirteen weeks after the initiation of treatment (as assessed with use of a 100-mm visual analog scale) and the treatment effect throughout twenty-six weeks.


RESULTS
For the overall intent-to-treat population, patients who were managed with sodium hyaluronate had greater pain relief than controls did; significant differences were noted at Week 7 (for the five-injection hyaluronate group), Week 17 (for the three and five-injection hyaluronate groups), and Week 26 (for the three-injection hyaluronate group). Analysis of the stratified populations clearly established that this effect was due to benefits experienced by the patients with osteoarthritis. The treatment effect through twenty-six weeks was significant in patients with osteoarthritis in the three-injection (p = 0.003) and five-injection (p = 0.002) groups, with no significant difference for either regimen in patients without osteoarthritis. The safety profile was very favorable, with no product-related serious adverse effects and no between-group differences for any reported adverse event.


CONCLUSIONS
Although the primary end point of this study (that is, improvement in terms of shoulder pain at thirteen weeks) was not achieved, the overall findings, including secondary end points, indicate that sodium hyaluronate (500 to 730 kDa) is effective and well tolerated for the treatment of osteoarthritis and persistent shoulder pain that is refractory to other standard nonoperative interventions.