A randomized controlled trial to compare the effect of ultrasound-guided hyaluronic or corticosteroid injections in patients with chronic subacromial bursitis.

Chronic subacromial bursitis (SAB) is a common shoulder disorder characterized by chronic shoulder pain with a painful arc of motion, which commonly occurs during abduction and sometimes during internal rotation of the shoulder. In addition, the extremes of all passive movements are painful. The range of motion (ROM) of the shoulder is usually not limited or is limited in a non-capsular pattern (mainly abduction and internal rotation). All resisted movements are painless or equally painful, and there is also tenderness over the deltoid region. The diagnosis of SAB remains doubtful until it is confirmed by an infiltration with local anesthetic.

The injections can be performed by palpation (using anatomical landmarks to place the needle) or with ultrasound (US) guidance (with visualization of the needle tip at the target location). The chief advantage of an ultrasound-guided intervention is the ability to use real-time, dynamic imaging without ionizing radiation. Previous studies have demonstrated that ultrasound-guided injection ensures correct needle placement and delivery of the medicine to the target, and improved clinical outcomes with ultrasound-guided subacromial-subdeltoid (SASD) corticosteroid injections.

Although SASD corticosteroid injections has been proven effective in treatment of chronic subacromial bursitis, in clinical practice, some patients fear the side effects of the corticosteroids. In the last few years, hyaluronic acid (HA) injection has been used for treatment of different kinds of shoulder disorders, including subacromial impingement syndrome, frozen shoulder, and rotator cuff tears, with variable results. However, treatment of chronic SAB with hyaluronic acid has never been reported before. Besides, some authors used combination of normal saline and lidocain as the placebo, which might not be a true placebo because lidocain can be an active medicine. Therefore, the purpose of this study is to compare the effectiveness of SASD corticosteroid, HA, and normal saline injection in treatment of patients with chronic SAB.

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