What Factors Are Associated With Prognosis of Rotator Cuff Disorder After Subacromial Hyaluronic Acid Injection

Objective: To evaluate the correlations between structure of supraspinatus tendon (impingement, tendinopathy or partial tear, as well as full thickness tear) on ultrasonography and its response to subacromial hyaluronic acid injection in rotator cuff disease patients and also investigate the factors associated with clinically important improvement after subdeltoid hyaluronic acid for rotator cuff disorder. Design: Prospective, longitudinal comparison study. Participants: Patients with rotator cuff disease Intervention: Three subacromial injection with hyaluronic acid with 2 week-interval. Main Outcome Measures: Visual analog scale (VAS) of the shoulder pain, Constant score, SPADI score, and angles of active shoulder range of motion (flexion, abduction, external rotation, and internal rotation) at pre-treatment, post-treatment at week 4 and post-treatment at week 12.