Ultrasound-guided subacromial injections of sodium hyaluronate for the management of rotator cuff tendinopathy: a prospective comparative study with rehabilitation therapy.

BACKGROUND Rotator cuff (RC) tendinopathy is a common cause of pain and shoulder dysfunction. The literature evidence suggests that a combination of overuse and extrinsic compression may induce chronic RC tendinopathy. Aim of the current study was to compare the results of subacromial sodium hyaluronate injections with rehabilitation therapy. MATERIALS AND METHODS We enrolled 48 patients (M/F: 26/22; mean age: 50 years; shoulder right/left: 29/19) with persistent shoulder pain for at least 4 months. Exclusion criteria were as follows: RC tear, calcifying tendinitis, glenohumeral instability, osteoarthritis, rheumatic diseases, physical therapy and/or injection in the previous 4 months, shoulder surgery, anesthetic nerve block, trauma, and severe medical diseases. The included subjects received either two ultrasound-guided subacromial hyaluronic acid (HA) injections (25 patients, HA group) at baseline and 14 days, or underwent rehabilitation therapy (23 patients, Physio group) including active shoulder mobilization, soft tissue stretching and humeral head positioner and propeller muscles strengthening for 30 days (3 sessions every week). Clinical assessment of shoulder function was performed with visual analog scale score for pain (0-100), Oxford Shoulder Score (OSS), and Constant-Murley Score (CS). Overall, patients were examined at baseline, week 2, week 4, week 12, and week 24. Statistical significance was set at 5 % (p < 0.05). RESULTS Reduction in overall pain in the HA group was statistically significant at week 2 (p < 0.05) week 4 (p < 0.05), week 12 comparing to baseline. Similarly, pain subscores (at night and with activity) were significantly lower at week 2 (p < 0.05), week 4 (p < 0.05), and week 12 (p < 0.05), respectively. In the Physio group, pain decreased significantly at week 2 (p < 0.05) but not maintained at week 4 (p > 0.05), week 12 (p > 0.05), and week 24 (p > 0.05). CS and OSS in the HA group increased significantly at week 2 (p < 0.05), week 4 (p < 0.05), and week 12 (p < 0.05). A non-statistically significant increase in clinical scores was found at week 24 (p > 0.05). A significant improvement of CS and OSS we found in the Physio group at week 2 (p < 0.05), but not at weeks 4, 12, and 24 (p > 0.05). CONCLUSIONS Subacromial HA injections could be an effective and safe alternative treatment for patients suffering from RC tendinopathy. We believe that the results of this study are encouraging but not lasting and we might suppose that a series of three to four subacromial sodium hyaluronate injections could provide good mid- and long-term clinical benefits.