82 Bursitis

Bursa

Bursa are sac-like structures found between tendons, ligaments, bone, and skin that provide protection and cushioning while allowing structures to move in relation to each other.  Amazingly, humans have over 150 bursae, many of which are lined with synovial membranes that produce and absorb the bursal fluid that is rich in collagen and proteoglycans.  These bursae are termed constant bursae and form during embryonic development.  Bursal fluid is similar in composition to synovial fluid and contains the oily hyaluronic acid, which helps to create a slippery fluid with low coefficient of friction.

Some bursae (termed adventitial bursae) form later in life in response to repetitive microtraumas and these bursae lack synovial endothelial cells and do not contain fluid.  Examples include those that develop over bunions.

Both types of bursae (constant and adventitial) can become inflamed when irritate or infected resulting in bursitis.

Risk Factors – Bursitis

Risk factors include repetitive physical activity and sedentary behaviour that prolongs stress on load-bearing bursae.  The highest incidence of bursitis occurs in runners, followed by occupations that involve heavy workload or frequent kneeling.  The wearing of tight high-heeled shoes is a risk factor for developing bunions (a deformity of the metatarsophalangeal joint and bone of the big toe, as well as inflammation of the bursal sac in that region).

Genetics and rheumatoid arthritis increase the risk of bunions, and bursitis in general, as does diabetes mellitus and HIV.

Uric acid crystal deposition associated with gouty arthritis (gout) can lead to bursitis, and is sometimes accompanied by kidney stones.

Running and rheumatoid arthritis as well as osteoarthritis are risk factors for developing bursitis associated with the anterior hip, knee, ankle and heel.

Common examples:

Bursa associated with rotator cuff muscles can become inflamed with overuse of the muscles and tendons in this region (e.g., subacromial bursitis).

Elbow bursa can become inflamed due to microtraumas accumulating from activities such as swimming, skiing, gymnastics and/or weightlifting giving rise to olecranon bursitis.

Ischiogluteal bursitis can occur due to excessive sitting (e.g., resulting in so called “weaver’s bottom”).

Frequent kneeling is linked to the development of what used to be called “housemaid’s knee” (prepatellar bursitis) or “clergyman’s knee” (infrapatellar bursitis).

Bursitis can also be caused by infections or acute trauma of the bursa.  Open wounds carry the risk of septic bursitis (bursitis caused by infection).  Infections of bursa with bacteria or fungi can also result from blood infections, or through the spread of cellulitis (most often caused by Staphylococcus aureus bacteria).

Pathogenesis – Bursitis

Irritation of the bursa often by repetitive movements or stresses can lead to microtrauma of bursa inducing inflammation.  Acute trauma, infection, or autoimmune dysfunction (e.g., rheumatoid arthritis, systemic lupus erythematosus, and gout) can also cause bursitis.  If bursitis does not resolve, it may lead to irritation and inflammation of surrounding tissues (e.g., tendons, muscles, ligaments, skin) which may increase pain, swelling and deterioration of tissues.

Obesity, smoking, fibromyalgia, hypothyroidism, alcoholism, diabetes mellitus, arthritis, and emotional stress correlate with slower and reduced healing and recovery.

Complications can involve an increased risk of deterioration of surrounding tissues, that are slow to heal and may not be able to fully regenerate (e.g., ligaments, tendons, muscles).  Potential complications include scarring that can impede range of motion.

Signs and Symptoms – Bursitis

Bursitis that is caused by repetitive movements or prolonged weight-bearing may develop insidiously and give rise to inflammation (swelling, redness, pain, warmth), tenderness, and impaired function.  Acute bursitis caused by trauma will also result in inflammation, and is often associated with damage to surrounding tissues and risk of infection.  Infections and septic bursitis may cause a fever to develop. Range of motion may decrease due to pain or swelling.  Chronic bursitis can lead to irritation, inflammation, and deterioration of surrounding tissues (e.g., tendons, ligaments, muscles) as well.

Diagnostic Tests – Bursitis

Physical examination and imaging may be used to diagnose bursitis and determine the extent of inflammation and/or damage to the bursa as well as any deterioration of surrounding structures.

Aspiration of the fluid and blood tests can be analyzed for the presence of infectious agents, crystals, and cell count.  Removal of exudate fluid can also be therapeutic reducing the debris, inflammation, pain and assisting in the healing process.

Imaging (e.g., ultrasound, x-ray) can be helpful in ruling out other causes and assessing the level of inflammation and damage.

Treatment – Bursitis

Treatment depends on the extent of the damage, but can involve surgery (e.g., bursectomy), orthotics, RICE, NSAIDs, acetaminophen, and topical anesthetics.  Infections require the use of antibiotics.  At times aspiration and/or corticosteroids are used.

Most often bursitis resolves without surgery, however surgical drainage and excision may be necessary, particularly with chronically inflamed bursae.

Treatment of severe bunions often require surgery to correct joint deformity, remove bony prominences, and reducing pain.

Progressive rehabilitative strategies (e.g., stretching and strength training that are gradually increased) are recommended to reduce chances of excess scarring and loss of ROM (e.g., adhesive capsulitis also known as frozen shoulder).