Bursitis

Bursitis is the inflammation of one or more bursae, which are synovial sacs filled with lubricating synovial fluid within the body. These bursae are lined with a synovial membrane that secretes the fluid, facilitating smooth and almost frictionless movement of muscles and tendons over bones.

The human body contains over 150 bursae, and their primary function is to reduce friction and cushion pressure points between bones and tendons or muscles around joints. When bursitis occurs, the inflamed bursae make movement difficult and painful, and the condition can perpetuate due to the movement of tendons and muscles over the inflamed area.

Signs and Symptoms

Bursitis commonly affects superficial bursae such as the subacromial, prepatellar, retrocalcaneal, and pes anserinus bursae located in the shoulder, knee, heel, and shin, respectively. Symptoms of bursitis range from localised warmth and erythema (redness) to joint pain and stiffness, and may include stinging pain around the joint with the inflamed bursa. The pain typically worsens during and after activity, and the affected area becomes stiff the following morning.

In some cases, bursitis in the shoulder joint can cause a snapping, grinding, or popping sound, a condition known as snapping scapula syndrome. Though this is not necessarily painful, it can be indicative of underlying bursitis.

Cause

Bursitis can have multiple concurrent causes, including trauma, autoimmune disorders, infections, and iatrogenic factors. Repetitive movement and excessive pressure are common causes, especially in the shoulders, elbows, and knees.

Inflammatory conditions such as rheumatoid arthritis, scleroderma, systemic lupus erythematosus, and gout can also lead to bursitis. Immune deficiencies, including HIV and diabetes, are additional risk factors. Though less common, scoliosis can sometimes cause shoulder bursitis, primarily due to overuse of the shoulder joint and related muscles.

Traumatic injuries that irritate the bursa, causing it to no longer fit the small area between the bone and the functionary muscle or tendon, can result in bursitis. In some instances, the cause remains unknown. Bursitis can also be associated with various chronic systemic diseases.

Diagnosis

Types

Common types of bursitis include:

• Prepatellar bursitis, also known as "housemaid's knee"
• Infrapatellar bursitis, or "clergyman's knee"
• Trochanteric bursitis, which causes pain over the lateral aspect of the hip
• Olecranon bursitis, referred to as "student's elbow," characterised by pain and swelling in the elbow
• Subacromial bursitis, the most common form, causing shoulder pain
• Achilles bursitis
• Retrocalcaneal bursitis
• Ischial bursitis, also called "weaver's bottom"
• Iliopsoas bursitis
• Anserine bursitis

Treatment

Differentiating between infected and non-infected bursitis is essential. Infected bursitis may present with surrounding cellulitis and systemic symptoms like fever. Aspiration of the bursa is necessary to rule out infection.

For non-infected bursitis, treatment focuses on symptom relief through rest, ice, elevation, physiotherapy, anti-inflammatory drugs, and pain medication. Since bursitis arises from increased friction with adjacent structures, compression bandages are not recommended as they can exacerbate the condition. Chronic bursitis may be treated with bursectomy and aspiration. Infected bursae require further investigation and antibiotic therapy, and steroid therapy may be considered.

If conservative treatments fail, surgical intervention may be necessary. In a bursectomy, the inflamed bursa is removed either endoscopically or through open surgery. The bursa typically regenerates without the inflammatory component after a few weeks.

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Self-assessment MCQs (single best answer)

What is bursitis?

What is the primary function of bursae in the human body?

Which of the following is a common symptom of bursitis?

What term is used to describe bursitis in the shoulder joint that causes a snapping, grinding, or popping sound?

Which of the following is NOT a cause of bursitis?

What is another name for prepatellar bursitis?

How is bursitis primarily diagnosed?

What is the first line of treatment for non-infected bursitis?

What procedure involves the removal of an inflamed bursa?

Which type of bursitis is characterised by pain over the lateral aspect of the hip?