Subacromial bursitis is a condition caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon (one of the four tendons of the rotator cuff) from the overlying coraco-acromial ligament, acromion, and coracoid (the acromial arch) and from the deep surface of the deltoid muscle. The subacromial bursa helps the motion of the supraspinatus tendon of the rotator cuff in activities such as overhead work. Musculoskeletal complaints are one of the most common reasons for primary care office visits, and rotator cuff disorders are the most common source of shoulder pain.Primary inflammation of the subacromial bursa is relatively rare and may arise from autoimmune inflammatory conditions such as rheumatoid arthritis, crystal deposition disorders such as gout or pseudogout, calcific loose bodies, and infection. More commonly, subacromial bursitis arises as a result of complex factors, thought to cause shoulder impingement symptoms. These factors are broadly classified as intrinsic (intratendinous) or extrinsic (extratendinous). They are further divided into primary or secondary causes of impingement. Secondary causes are thought to be part of another process such as shoulder instability or nerve injury.In 1983 Neer described three stages of impingement syndrome. He noted that "the symptoms and physical signs in all three stages of impingement are almost identical, including the impingement sign..., arc of pain, crepitus, and varying weakness". The Neer classification did not distinguish between partial-thickness and full-thickness rotator cuff tears in stage III.
Treatment
Many non-operative treatments have been advocated, including rest; oral administration of non-steroidal anti-inflammatory drugs; physical therapy; chiropractic; and local modalities such as cryotherapy, ultrasound, electromagnetic radiation, and subacromial injection of corticosteroids.Shoulder bursitis rarely requires surgical intervention and generally responds favorably to conservative treatment. Surgery is reserved for patients who fail to respond to non-operative measures. Minimally invasive surgical procedures such as arthroscopic removal of the bursa allows for direct inspection of the shoulder structures and provides the opportunity for removal of bone spurs and repair of any rotator cuff tears that may be found. Early / initial
Middle / intermittent
Late / return to function
Prognosis
In 1997 Morrison et al. published a study that reviewed the cases of 616 patients (636 shoulders) with impingement syndrome (painful arc of motion) to assess the outcome of non-surgical care. An attempt was made to exclude patients who were suspected of having additional shoulder conditions such as, full-thickness tears of the rotator cuff, degenerative arthritis of the acromioclavicular joint, instability of the glenohumeral joint, or adhesive capsulitis. All patients were managed with anti-inflammatory medication and a specific, supervised physical-therapy regimen. The patients were followed up from six months to over six years. They found that 67% (413 patients) of the patients improved, while 28% did not improve and went to surgical treatment.