A common cause of painful shoulder pain, subacromial bursitis is characterized by inflammation of the subacromial bursa, a kind of flattened pad that promotes the sliding of the anatomical structures of the shoulder. It is often associated with tendon pathology. In the event of chronic pain, medical treatment is preferred, surgery being the last resort.

Definition

Subacromial bursitis is inflammation of the subacromial bursa, a serous bursa – or synovial bursa – shaped like a flattened sac, located under the protrusion of the scapula called the acromion. Filled with synovial fluid, this pad is located at the interface between the bone and the tendons of the rotator cuff enveloping the head of the humerus. It facilitates sliding when the shoulder joint is mobilized.

The subacromial bursa communicates with another serous bursa, the subdeltoid bursa, located between the major tubercle of the head of the humerus and the deltoid. We sometimes speak of a subacromio-deltoid bursa.

Subacromial bursitis causes acute or chronic pain and usually induces limitation of movement.

Causes

Subacromial bursitis is most often of mechanical origin and may be associated with rotator cuff tendinopathy or tendon cracking. 

A subacromial conflict is frequently present: the space under the acromion is too limited and the bony relief tends to “catch” the tendon when the shoulder is mobilized, causing a painful inflammatory reaction in the bursa. subacromial.

Inflammation of the bursa causes it to thicken, which increases the frictional forces, with the effect of sustaining the inflammation. The repetition of movement aggravates this phenomenon: the friction of the tendon promotes the formation of a bony beak (osteophyte) under the acromion, which in turn stimulates tendon wear and inflammation.

Bursitis is sometimes also a complication of calcifying tendinopathy, calcifications being the cause of very intense pain.

Diagnostic

Diagnosis is mainly based on clinical examination. A painful shoulder can have different causes and, to identify the lesions in question, the doctor carries out an examination as well as a series of maneuvers (elevations or rotations of the arm along different axes, elbow stretched or bent, against resistance or not … ) that allow him to test the mobility of the shoulder. In particular, it evaluates muscle strength as well as the reduction in range of motion and looks for positions that trigger pain.

The imaging workup completes the diagnosis:

• x-rays do not provide information on bursitis, but can detect calcifications and visualize the shape of the acromion when a subacromial impingement is suspected.
• Ultrasound is the exam of choice for assessing soft tissue in the shoulder. It makes it possible to visualize lesions of the rotator cuff and sometimes (but not always) bursitis.
• Other imaging examinations (arthro-MRI, arthroscanner) may be necessary.

The people concerned

Along with the elbow, the shoulder is the joint most affected by musculoskeletal disorders. Shoulder pain is a frequent reason for consultation in general medicine, and bursitis and tendinopathy dominate the picture.

Anyone can get bursitis, but it is more common in those in their forties and fifties than in younger people. Athletes or professionals to whom their profession requires repeated actions are exposed earlier.

Risk factors

• Carrying out very repetitive movements for more than 2 hours a day
• Work the hands above the shoulders
• Carrying heavy loads
• Trauma
• Age
• Morphological factors (shape of the acromion)…

Pain

Pain is the main symptom of bursitis. It manifests itself in the shoulder region, but most often radiates to the elbow, or even to the hand in the most severe cases. It is aggravated by certain lifting movements of the arm. Nighttime pain is possible.

The pain can be acute during a trauma, or onset gradually and then chronic. It can be very sharp in cases of hyperalgesic bursitis linked to calcifying tendonitis.

Mobility impairment

There is sometimes a loss of range of motion, as well as difficulty in performing certain gestures. Some people also describe a feeling of stiffness.

Rest and functional rehabilitation

First, resting (removal of pain-triggering gestures) is necessary to reduce the inflammation.

Rehabilitation must be adapted to the nature of the bursitis. In the event of a subacromial impingement, certain exercises aimed at reducing the friction between the bone and the tendons during shoulder movements may be useful. Muscle strengthening exercises may also be recommended in some cases.

Ultrasound offers some effectiveness when the bursitis is due to calcifying tendonitis.

Medical treatment

It uses nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics, which are often effective in the short term.

Corticosteroid injections into the subacromial space may provide relief.

Surgery is a last resort solution after well-conducted medical treatment.

Acromioplasty aims to suppress the conflict between the bursa, the rotator cuff and the bone structures (acromion). Performed under general or loco-regional anesthesia, it uses a minimally invasive technique (arthroscopy) and aims to clean the subacromial bursa and, if necessary, to “plan” the bony beak on the acromion.

Alert pains should not be overlooked. Adopting good gestures during work, sports or even daily activities can prevent subacromial bursitis from becoming chronic.

Occupational physicians and sports physicians can help identify risky acts. An occupational therapist can suggest specific measures (adaptation of workstations, new organization to avoid repetition of actions, etc.) useful in prevention.