Bursitis

Bursitis Overview

Bursae (one is a bursa) are fluid-filled sacs that cushion areas of friction between tendon and bone or skin. Like air-filled bubble wrap, these sacs reduce friction between moving parts of the body, such as in the shoulder, elbow, hip, knee, and heel.

The number varies, but most people have about 160 bursae throughout the body. Bursae are lined with special cells called synovial cells, which secrete a fluid rich in collagen and proteins. This synovial fluid acts as a lubricant when parts of the body move. When this fluid becomes infected by bacteria or irritated because of too much movement, the painful condition known as bursitis results.

Bursitis Causes

The most common causes of bursitis are trauma, infection, and crystal deposits.

Trauma

Trauma causes inflammatory bursitis from repetitive injury, which results in widening of the blood vessels. This allows proteins and extracellular fluid into the bursae and the bursae react against these "foreign" substances by becoming swollen.

• Chronic: The most common cause of chronic bursitis is minor trauma that may occur to the shoulder (subdeltoid) bursa from repetitive motion, for example, throwing a baseball. Another example is prepatellar bursitis (in front of the knee) from prolonged or repetitive kneeling on a hard surface to scrub a floor or lay carpet.
  
  
• Acute: A direct blow (let's say you accidentally bang your knee into a table) can cause blood to leak into the bursa. This rapid collection usually causes marked pain and swelling, most often in the knee.

Infections

Bursae close to the surface of the skin are the most likely to get infected with common organisms; this is called septic bursitis. These bursitis-causing bacteria are normally found on the skin: Staphylococcus aureus or Staphylococcus epidermis. People with diabetes or alcoholism and those undergoing steroid treatments or with certain kidney conditions, or who may have experienced trauma may be higher risks for this type of bursitis. About 85% of septic bursitis occurs in men.

Crystal deposits

People with certain diseases such as gout, rheumatoid arthritis, or scleroderma, for example, may develop bursitis from crystal deposits. Little is known about how this process happens. Uric acid is a normal byproduct of daily metabolism. People who have gout are unable to properly break down the uric acid, which crystalizes and deposits in joints-a mechanism for causing bursitis.

Bursitis Symptoms

Bursitis causes pain and tenderness around the affected bone or tendon. The bursae sacs may swell, often making movement difficult. The most commonly affected joints are the shoulder, elbow, wrist and hand, knee, and foot.

Elbow

Olecranon bursitis is the most common form of bursitis. Goose-egg-like, tender red swelling may appears just behind the elbow. This area is at the top of one of the forearm bones called the ulna and is known as the olecranon process.

• The pain may increase if the elbow is bent because tension increases over the bursa.
  
  
• This bursa is frequently exposed to direct trauma (bumping your arm) or repeated motions from bending and extending the elbow (while painting, for example).
  
  
• Infection is common in this bursa.

When to Seek Medical Care

Because bursitis can be infectious and needs to be treated with antibiotics, it is best to see a doctor the first time you recognize symptoms. Once the diagnosis has been made, you will probably be able to manage further episodes at home.

If the pain is not getting better with home care, your doctor may be able to offer some alternatives such as an injection of the area with steroids.

Fever is a definite sign to seek immediate medical care because it may signify infection. Heed other warning signs of infection such as constant warmth or redness around the joint or severe tenderness. Skin infections around the area (cellulitis) may mean that the bursa is infected as well.

Medical Treatment

If your bursitis is not infectious, the doctor may inject the bursa with a corticosteroid to reduce inflammation. The results last for varying lengths of time. Because of potential complications, injections are usually given no more than 3 times per year at least 30 days apart.

If your bursitis is infectious, the bursa will be drained with a needle. The doctor will prescribe antibiotics to be taken in pill form. If the infection is very serious, or does not respond to oral antibiotics, or if your immune system is weakened for another reason, you may be admitted to the hospital for IV antibiotics. Most causes of infectious bursitis, however, can be managed safely at home.