A bursa is a small flat cushion-like structure usually found in between a muscle and a bone. It helps provide protection and reduces friction. It is sometimes thought of as a small fluid-filled cushion, one to three inches in size, but usually it is quite flat, similar to a barely filled plastic bag of water. These are present in many areas of our skeletal system, and frequently cause pain in the knees, shoulders, elbows and hips. There are two main knee bursae, and several others. One is on the inside of the knee, just below the joint. The other main bursa is in front of the kneecap.
Pain will occur when the bursa becomes injured, pinched or inflamed. When the bursa is inflamed, it is called bursitis (the ‘itis’ refers to something that is inflamed - like appendicitis). When the bursa is inflamed or injured, the bursa produces more fluid causing swelling and pain.
Bursitis in this location is called anserine bursitis. A bursa may become painful with injury or strenuous or repetitive activities. Sometimes knee bursitis is due to a more serious disease, such as rheumatoid arthritis or even infection.
When the knee is at rest there is less pain, but it usually will feel painful with walking, pressing on the inside of the knee is painful, and occasionally redness and swelling is present. The pain may be very sharp if the bursitis is severe.
Along with a history of the knee symptoms, an examination will suggest bursitis is present. Usually X-rays are done, but because the bursa is made of soft tissue, X-rays or CT scans are often not sufficient. An MRI or ultrasound examination may show if bursitis is present.
The treatment of knee bursitis depends upon the cause and severity of the pain. In general, if pain does not improve with ice and rest, then medical evaluation is a good idea. Physical therapy and an anti-inflammatory medication may be tried to reduce pain from bursitis. More severe pain may be treated with removal of fluid or injections of cortisone-like medications into the knee bursa. Rarely, surgery may be required to remove the bursa.
Medication may be used to reduce bursitis pain. These may include over the counter medications such as Tylenol (generic = acetaminophen) Aleve (generic = naproxen), Motrin (generic = ibuprofen) or aspirin. Prescription medications which belong to a group of medications called ‘non-steroidal anti-inflammatory medications (or ‘NSAIDs’ for short) are commonly recommended. Some of the more commonly prescribed of these include medications such as Celebrex, Motrin, Naprosyn, Mobic,Voltaren, Relafen and Lodine. (a complete list is available at the reference below).