A bursal sac is a sac filled with fluid that provides a cushion between muscles or tendons and bones to decrease friction and irritation. Bursal sacs are located around most joints within the body. When the bursal sac gets infected or inflamed, it can lead to a painful condition called bursitis. Bursitis is often caused by repetitive movement or overuse of the joint, which may be a result of playing sports, intense physical activity, or in some cases, it may be caused by an injury. Arthritis of a joint may put added stress on a bursa sac, and may also cause bursitis.
The most common symptoms of bursitis are pain, stiffness, swelling, and tenderness, which may affect the joints of the elbow, shoulder, hip, knee, or ankle. The heel and Achilles tendon may also be affected. Pain may be gradual or sudden and severe, and may be accompanied by decreased mobility of the joint.
If conservative treatment methods are unsuccessful in treating the pain and discomfort caused by bursitis, bursal sac injections can be an effective method of treatment to reduce inflammation and diminish pain. Anti-inflammatory steroid medication is injected directly into the bursal sac and as the inflammation decreases, pain and discomfort subside. Bursal sac injections can bring rapid relief to the pain of bursitis, and patients may find relief from their symptoms for a few weeks or up to a few months. In some cases, one injection may be sufficient to alleviate the symptoms of bursitis.