Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
A bursa is a fluid-filled sac that functions as a gliding surface to reduce friction between moving tissues
of the body.
There are three major bursae of the knee.
Bursitis is usually not infectious, but the bursa can become infected.
Treatment of noninfectious bursitis includes rest, ice,
and medications for inflammation and pain. Infectious bursitis is treated with
antibiotics, aspiration, and surgery.
What is bursitis?
A bursa is a closed, fluid-filled sac that functions as a gliding surface to reduce friction between tissues of the body.
Bursae is plural for bursa. The major bursae are located adjacent to the tendons near the large joints, such as the shoulders, elbows, hips, and knees. When a bursa becomes inflamed, the condition is known as bursitis. Most commonly, bursitis is caused by local soft-tissue trauma or strain injury, and there is no infection (aseptic bursitis). On rare occasions, particularly when the immune system is suppressed, the bursa can become infected with bacteria. This condition is called septic bursitis.
The knee joint is surrounded by three
major bursae. At the tip of the knee, over the kneecap bone, is
the prepatellar bursa. This bursa can become inflamed (prepatellar
bursitis) from direct trauma to the front of the knee. This commonly
occurs when maintaining a prolonged kneeling position. It has been referred
to as "housemaid's knee," "roofer's knee," and "carpet
layer's knee," based on the patient's
associated occupational histories.
Bursitis of the knee can occur when the bursa fills with blood from injury and overuse, such as from athletic competition. Bursitis can also occur from rheumatoid arthritis and from deposits of crystals, as seen in patients with gouty arthritis and pseudogout. The prepatellar bursa can also become infected with bacteria (septic bursitis). When this happens, fever may be present. This type of infection usually occurs from breaks in the overlying skin or puncture wounds. The bacterium involved in septic bursitis of the knee
is usually Staphylococcus, which is normally present on the skin. Rarely, a chronically inflamed bursa can become infected by bacteria spreading through the blood.
Cortisone injections can be used to treat the inflammation of small areas of the body (local injections), or they can be used to treat inflammation that is widespread throughout the body (systemic injections). Examples of conditions for which local cortisone injections are used include inflammation of a bursa (bursitis of the hip, knee, elbow, or shoulder), a tendon (tendinitis such as tennis elbow), and a joint (arthritis).