Atlas of pathophysiology, 2 Edition

Part II - Disorders

Musculoskeletal disorders

Bursitis

Bursitis is a painful inflammation of one or more of the bursae—closed sacs lubricated with small amounts of synovial fluid that facilitate the motion of muscles and tendons over bony prominences. Bursitis usually occurs in the subdeltoid, olecranon, trochanteric, calcaneal, or prepatellar bursae.

Causes

·   Recurring trauma that stresses or presses a joint

·   Inflammatory joint disease, such as rheumatoid arthritis or gout

·   Chronic bursitis—repeated attacks of acute bursitis, trauma, or infection

·   Septic bursitis—wound infection; bacterial invasion of overlying skin

Pathophysiology

The role of the bursa is to act as a cushion and allow the tendon to move over bone as it contracts and relaxes. It's a fibrous sac lined with synovial fluid. Bursitis is an inflammation of the bursa. The inflammation leads to excessive production of fluid in the sac, which becomes distended and presses on sensory nerve endings, causing pain.

Signs and symptoms

·   Irritation

·   Inflammation

·   Swelling

·   Warmth over the affected joint

·   Sudden or gradual onset of pain and limited movement

Site-specific

·   Subdeltoid bursa—limited arm abduction

·   Prepatellar bursa—so-called housemaid's knee; pain when climbing stairs

·   Hip bursa—pain when climbing, squatting, crossing legs

Diagnostic test results

Bursitis typically occurs concurrently with tendinitis, and the two may be difficult to distinguish as discrete problems. X-rays are usually normal in the early stages. In calcific bursitis, they may show calcium deposits.

Treatment

·   Resting joint by immobilization with a sling, splint, or cast

·   Application of cold or heat

·   Ultrasonography

·   Mixture of a corticosteroid and an anesthetic such as lidocaine injected into bursal sac for immediate pain relief

·   Nonsteroidal anti-inflammatory drugs until patient is free of pain and able to perform range-of-motion exercises easily

·   Short-term analgesics, such as propoxyphene, codeine, acetaminophen with codeine, and, occasionally, oxycodone

·   For chronic bursitis, lifestyle changes to prevent recurring joint irritation

·   Antibiotics

·   Surgical drainage of the bursa

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BURSITIS OF THE HIP AND KNEE

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