What Causes Knee Bursitis?

Knee Bursitis

Knee bursitis is a condition caused by swelling of a fluid-filled sac located around the cap of the knee. The sac is called a bursa. Its normal purpose is to provide a smooth surface between knee tissue to lessen the friction movement caused by the kneecap.

Knee joints are surrounded by three of these liquid-filled sacs. When the sac at the top of the knee swells because of a fall or other trauma to the knee, the condition is called knee bursitis.

Causes of Knee Bursitis

The medical condition knee bursitis is commonly called housemaid's knee, catcher's knee or carpenter's knee, because the injury can be caused by kneeling for long periods of time. It gets its nicknames due to occupations that involve kneeling for long periods of time.

The kneeling leads to multiple symptoms including swelling, redness, warmth, tingling sensations, impressions and extreme sensitivity. Knee bursitis is not as painful as arthritis of the knee, but it can be misdiagnosed as arthritis. Stiffness is another symptom. The range of motion for the knee is usually not affected.

A slight variation of knee bursitis is prepatellar bursitis, which is when blood fills the bursa, causing swelling and inflammation. Arthritis can set off knee inflammation, as can bacterial infections.

Another variation of knee bursitis is jumper's knee, or infrapatellar bursitis. This is when the bursa under the knee swells, applying extreme pressure to the tendons working around the knee.

Treatments

Mild and moderate cases of knee bursitis are treated with rest, elevation, ice, pain medication, aspirin and anti-inflammatory medication.

Severe cases of the condition can require aspiration, which is removal of bursa fluid from the sac with a needle and is done at a doctor's office. This procedure should never be attempted without a doctor's supervision. It requires sterile conditions, and the removed fluid needs to be send to a laboratory for analysis.

Another form of treatment for knee bursitis is injection of cortisone into the sac.

Knee bursitis that is the result of bacterial infections requires additional medical attention and treatment. The fluid has to be removed from the bursa by aspiration and sent to a lab to isolate the bacteria and proceed with treatment.

In some severe cases, removal and drainage has to be done through surgery. However, the surgical option is usually in cases of bacterial infection.