Bursas

Bursae are small, fluid-filled sacs located around joints and soft tissues that function as cushions to reduce friction between moving parts such as bones, tendons, and skin. When a bursa becomes inflamed, the condition is called bursitis. There are many bursae in the body, and their number varies among individuals; some are superficial and palpable, while others are deeper within a joint.

Commonly affected bursae include the prepatellar and infrapatellar bursae around the knee, the olecranon bursa at the elbow, the subacromial-subdeltoid bursa in the shoulder, the trochanteric bursa near the hip, and the ischial or retrocalcaneal bursae near the buttocks and heel. Bursae can be classified as subcutaneous (near the skin) or deep (near a joint cavity or tendon).

Bursitis can result from repetitive motion or prolonged pressure, direct trauma, or inflammatory or infectious conditions. Risk factors include kneeling for long periods (housemaid’s knee), repetitive elbow leaning, or certain systemic diseases such as gout or rheumatoid arthritis. Septic bursitis, caused by infection, requires urgent assessment.

Symptoms typically include localized swelling, warmth, pain, and sometimes reduced range of motion. Diagnosis relies on clinical examination and may be supported by imaging, such as ultrasound or MRI. Fluid aspiration with analysis (cell count, culture, crystals) helps distinguish septic bursitis from non-infectious inflammation.

Treatment is usually conservative: rest, ice, compression, elevation, and nonsteroidal anti-inflammatory drugs. Depending on severity, aspiration of the bursa fluid and corticosteroid injection may be used. Antibiotics are necessary for infection; persistent or recurrent bursitis may require surgical bursectomy in rare cases. Prevention focuses on avoiding repetitive stress and using padding or protective gear.