Baker's Cyst

Baker's Cyst

A Baker’s cyst, also called a popliteal cyst, causes swelling behind the knee. A Baker’s cyst consists of a pocket of synovial (joint) fluid that leaked from a tear in the joint capsule. It is commonly caused by arthritis.

The cysts rarely occur in children. A Baker’s cyst can be caused by a knee injury. Wrapping the knee and applying cold compresses may reduce the swelling. A Baker’s cyst is usually painless, but can cause discomfort and be slightly tender.

The Baker’s cyst can rupture and allow the synovial fluid to leak into the calf or down the inside of the calf to the ankle. The fluid in the leg may give the appearance of a painless bruise. If the swelling persists or worsens, avoid putting pressure on the joint. Avoid squatting and kneeling. If the cyst restricts movement or causes pain, it can be surgically removed.

The doctor may choose to drain the fluid in the cyst. The doctor may administer a steroid injection. When treating a Baker’s cyst, it is important to remember that the underlying cause needs to be addressed. If the tear in the joint capsule is not surgically repaired, the cyst is likely to recur.