Effect of Ultrasound-guided Hyaluronic or Corticosteroid Injections in Patients With Chronic Subacromial Bursitis

Inclusion Criteria: 1. shoulder pain for more than 1 month 2. age ≥ 20 years old 3. painful abduction or internal rotation with a visual analog scale (VAS) pain score ≥4 4. the presence of a painful arc of motion or pain at the middle to terminal range of shoulder abduction or internal rotation with a soft end feel 5. tenderness over the subacromial bursa 6. a reduction in pain of ≥40% on active shoulder abduction or internal rotation at the terminal range after injection of 3ml of 1%lidocain into the SASD bursa under ultrasound (US) guidance. Exclusion Criteria: 1. a history of uncontrolled chronic diseases, e.g., malignant neoplasms, blood dyscrasia, and infection 2. previous surgery of the affected shoulder 3. any evidence of a rotator cuff tear or tendinopathy, demonstrated by positive resistive tests or sonographic findings 4. calcification of the rotator cuff, demonstrated by x-ray or sonographic findings 5. the presence of arthritis, such as inflammatory arthritis (e.g., rheumatoid arthritis, seronegative spondyloarthropathy, or crystal-related arthropathy), osteoarthritis, frozen shoulder, subacromial spurs, or deformity of the acromion 6. the presence of instability of the affected shoulder 7. a previous fracture near the shoulder region 8. the presence of cervical radiculopathy or myelopathy 9. having received a corticosteroid or hyaluronic acid subacromial or shoulder joint injection in the past 3 months