Subacromial bursitis refers to an inflammation of the subacromial bursa. The subacromial bursa is located between the supraspinatus tendon below and the coraco-acromial ligament, the coracoid, the acromion, and the inferior surface of the deltoid muscle above .
Patients with subacromial bursitis often present with a history of trauma, inflammatory joint diseases such as SLE, gout, and rheumatoid athritis, or repetitive movement of the shoulder over the head from sporting or work-related activities.
Subacromial bursitis presents with localized tenderness over the greater tubercle of the humerus and over the shoulder, erythema of the skin over both areas, local edema, and reduced range of motion particularly abduction. The inflammation also presents with warmth of the skin overlying the bursa.
Chronic bursitis results in disuse of the shoulder leading to atrophy and weakness of the ligaments and muscles of the shoulder joint. Physical examination may be used to distinguish bursitis from other musculoskeletal diseases: a reduction in both active and passive range of motion suggests musculoskeletal diseases and not bursitis. In bursitis, passive range of motion is intact.
Laboratory blood studies are usually not necessary in subacromial bursitis, except in cases of septic bursitis in which white blood cell count and erythrocyte sedimentation rate are necessary and are typically elevated. In septic subacromial bursitis, blood cultures may also be necessary. Furthermore rhematoid factor (RF), antinuclear antibody (ANA) and anti-citric citrllinated peptide (anti-CCP) tests may also be done to exclude underlying inflammatory or autoimmune diseases.
Bursal fluid aspiration for analysis is necessary for suspected infectious or rheumatic bursitis. This may also be a therapeutic procedure to reduce the fluid content of the bursa. In nonseptic bursitis, white blood cell count in the bursal fluid is often lower than 2000/µL with mononuclear cells being predominant. However, in septic bursitis white blood cell counts exceed 70,0000/µL with the polymorpomonuclear( PMN) cells being predominant. A white blood cell count of between 5,000 and 20,0000 is still suggestive of septic bursitis. Gram stain and culture of the joint fluid are also considered to evaluate an infective bursitis, however, a negative gram stain doesn't exclude septic bursitis. Bursal fluid culture is the diagnostic test of choice to confirm septic bursitis. Chronic and recurrent subacromial bursitis require the exclusion of tuberculosis, hence bursal fluid for acid fast bacilli (AFB) is recommended.
Imaging studies are usually not necessary in making a diagnosis of subacromial and other forms of bursitis, but they may be necessary to exclude underlying gross bone pathology such as fractures. Plain radiographs may reveal joint effusions and calcification of the bursal walls and tendons in chronic bursitis. Magnetic resonace imaging (MRI), although not routinely indicated, may reveal bursal abscesses . It is highly sensitive for the diagnosis of bursitis and necessary for excluding suspected bone malignancies.
Bone ultrasonography is usually not sensitive for bursitsis, but it is indicated for guidance in bursal fluid aspiration or therapeutic injections. Studies to prove its efficacy over injections or aspirations without ultrasound guidance have yielded controversial results . Ultrasonography is necessary in distinguishing cystic from solid masses and in the diagnosis of popliteal bursitis (Baker cysts) when it coexists with other joint disorders .
Treatment approach is similar for all types of bursitis irrespective of the location. Treatment of bursitis basically begins with lifestyle modification and conservative medical care. In the case of subacromial bursitis, lifestyle modifications include avoidance of inciting or aggravating activities such as swimming, heavy lifting, and sporting activities which requires frequent lifting of the arms over the head.
Rest of the affected shoulder is very essential in the management of subacromial bursitis. However, stretch exercises are also beneficial to prevent weakening of the muscles and ligaments of the shoulder joint which may aggravate the pain and inflammation. Application of ice packs on the affected area is also important especially within the first 24 hours of onset of symptoms. Ice packs are effective if applied several times daily for at least 10 minutes each time. To prevent skin irritation, ice should not be applied directly to the skin.
Corticosteroid injections are the second line of treatment if the conservative management fails . Corticosteroid are indicated in all sites of bursitis except retrocalcaneal bursa because of the possibility of tendon rupture. They are also not indicated in infective bursitis.
Surgery is the final treatment option indicated if every other option fails to resolve the symptoms of bursitis, and consists in a procedure called bursectomy  . Surgical treatment of subacromial bursitis involves a subacromial decompression.
A study by Morrison et al reveals that the prognosis of the bursitis depends on age, such that patients who are aged 20 or younger and those aged between 41 and 60 fared better than those aged between 21 and 40. This may be attributed to the increased work stress, tendency for sports engagement, and overuse of shoulder muscles in this age group. Patients older than 60 years often have the poorest outcome due to the coexisting degenerative changes in the rotator cuff structures with ageing, however, the authors attributed the poor outcome in these individuals to undetected full-thickness tears of the tendons of the rotator cuff muscles .
Subacromial bursitis results from tendinitis of the rotator cuff muscles particularly the supraspinatus being directly under the bursa. Injury to the rotator cuff muscles may be acute such as a strain or trauma, or chronic from overuse. Chronic injury to the rotator cuff muscles may be as a result of supraspinatus tendonitis sequel to prolonged impingement of the tendon between the coraco-acromial arch and the humeral head. Activities which predispose to such tendonitis generally are those which require the arms to be moved over the head repeatedly. These include serving ball in racket sports, swimming backstroke or butterfly patterns, and pitching in baseball. Such repeated arm movements are also common among painters and wallpaper hangers making these jobs important risk factors for developing subacromial tendinitis.
Another factor which makes the supraspinatus tendon susceptible to injury is the poor vascularity at its insertion to the greater tubercle of the humerus. The consequent inflammation further narrows the subacromial space exercebating the tendon injury and causing subacromial bursitis. Furthermore, if the inflammation is not controlled, it could result in a complete or partial tear of the tendon.
Rotator cuff tendinitis is not always sport-related, degenerative tendinitis may occur in non-athletes over the age of 40.
Bursitis constitutes 0.4% of cases in general practice. Commonly encounted bursitis include subdeltoid, trochanteric, prepatellar, olecranon, and ischial bursitis.
Bursitis are commonly encountered in athletes with an incidence rate of up to 10% in runners. As noted in a French study done to determine the incidence of knee bursitsis among male workers, knee bursitis occurred more in the male workers whose jobs required frequent kneeling .
Bursitis is not associated with significant mortality. Outcome is excellent with adequate treatment and follow up.
Inflammation of the bursa results in proliferation of the synovial cells with a resultant increase in collagen production and deposition. This synovial cell multiplication is associated with exudation of protein-rich fluid and subsequent local edema. The fluid may become hemorrhagic . This process is suggested to be mediated by cytokines, cyclooxygenases, and metalloproteinases. The associated fibrosis from collagen synthesis causes replacement of the bursal lining by granulation tissue.
There are three phases of bursitis: acute, chronic, and recurrent . The acute phase presents with local inflammation and painful movement around the joint related to the bursa. Chronic bursitis results from poor or lack of treatment of an acute bursitsis. This results in worsened pain and weakening of the overlying ligaments and tendons from disuse atrophy.
The subacromial bursa becomes inflamed secondary to injury of the supraspinatus tendon, therefore, both conditions are often coexistent. The tendinitis may further progress to causing partial or complete-thickness tears of the tendon.
Prevention of subacromial bursitis basically involves avoidance of shoulder overuse and limiting activities which put stress on the shoulder like sporting activities such as swimming, baseball and racket sports. In individuals in whom restricting these activities may be difficult, such as in athletes and in persons with at-risk jobs, protective pads on the shoulders are recommended.
Subacromial bursitis refers to an inflammation of the subacromial bursa which is located between the undelying supraspinatus tendon and the overlying acromial arch (consisting of the coraco-acromial ligament, the acromion, the coracoid and the deltoid muscle. The bursae are fluid-containing sac-like structures found between skin and bones, or between bones and tendons. Bursae are lined by synovial tissues which produce fluid which serves as a lubricant reducing friction between these tough structures as they glide over each other during the movement of the joint.
Subacromial bursitis, like all other forms of bursitis, occurs as a result of inflammatory changes in the synovial lining, which makes it thickened, producing excess fluids which in turn causes local edema and pain. Subacromial bursitis is caused by a primary inflammation of the supraspinatus tendon which results from acute injury, overuse, degenerative changes, or underlying chronic inflammatory diseases such as gout. These are implicated in the etiopathogenesis of all forms of bursitis. Furthermore, bursitis may result from infective causes, however, these are rarely implicaed in subacromial bursitis.
Symptoms of subacromial bursitis include shoulder pain which is worsened by movement of the shoulder and the difficulty in moving the arm around the shoulder joint. Physical examination usually reveals tenderness, erythema, and local edema over the joint.
Treatment of subacromial bursitis follows the same basic principles as other forms of bursitis. This include an initial conservative approach involving restriction of aggravating activities, cold compression, rest, and analgesia. If these methods fail to resolve the symptoms, intralesional cortcosteroids are recommended. Surgical removal of the bursa is recommended in unresponsive or chronic cases.
Bursitis is an inflammation of the bursa (plural form is bursae). Bursae are fluid-containing sac-like structures which occur naturally between bones and skin, bones and tendons, or bones and ligaments.
Subacromial bursa is the inflammation of the subacromial bursa. The subacromial bursa is located between the tendon of a muscle called supraspinatus muscle and the ligaments and bones of the shoulder joint.
Subacromial bursitis is caused by inflammation of the supraspinatus tendon( tendinitis). This tendinitis can be caused by direct injury, falls or blows to the shoulder resulting in injury to the rotator cuff muscles. The rotator cuff muscles consists of four muscles (teres minor, subscapularis, infraspinatus, and supraspinatus) which are responsible for moving the shoulder up, down, and sideways). Repeated movements of the arm over the head as in sports such as baseball, swimming, and racket sports are common causes of rotator cuff muscle tendinitis. Jobs which place an individual at risk of subacromial bursitis include painting and wallpaper hanging.
Ageing has been implicated in the cause of subacromial bursitis in those older than 40 years. Subacromial bursitis, like all other forms of bursitis, may also result from underlying inflammatory diseases of the joints such as gout and lupus.
Subacromial bursitis usually presents with shoulder pain which is worse when moving the shoulder over the head, mild swelling of the shoulder, weakness of the muscles of the affected shoulder, redness and warmth of the skin over the shoulder. If infection is the cause of the bursitis, fever may be present.
Diagnosis of subacromial bursitis can be made initially from the history and physical examinations. The history consists of questions which the doctor would ask the patient to determine what must have caused the presenting symptoms.
Blood workup is not necessary to confirm subacromial bursitis but may be recommended to exclude other causes of similar symptoms. However, blood cultues would be ordered if an infective cause is suspected.
X-rays, Magnetic resonance imaging (MRI), Ultrasound and Contrast Tomography (CT) scans are not routinely indicated for confirmation of the diagnosis but may help in ruling out other bone diseases such as bone cancers.
The diagnostic investigation necessary in bursitis is aspiration and analysis of the fluid in the bursa. This fluid may be analysed for white blood cell count, bacterial infection, and other inflammatory diseases.
The treatment of subacromial bursitis follows the same principle as for other forms of bursitis. It consists of an initial conservative treatment which includes resting the affected joint, application of ice packs over the area everyday for 10 minutes each time, avoiding activities which worsen or trigger the pain, stretch exercises as recommended by a physiotherapist, and use of over-the-counter pain killers.
This conservative treatment is often successful. However, it is fails, your doctor may recommend injecting steroids into the bursa. If all else fails, surgical removal of the bursa, called bursectomy, is the final option.