Baker's Cyst

What is a Baker's cyst?

A Baker's cyst is an abnormal swelling of a bursa (a fluid-filled sac) behind the knee.

How does it occur?

No one really knows what causes a Baker's cyst. However, a cyst can occur when the lining of the knee joint produces too much fluid after an injury or in certain kinds of arthritis. They can occur with tears of the meniscus.

What are the symptoms?

You may have pain, swelling, or a feeling of fullness in the area behind the knee.

How is it diagnosed?

Your healthcare provider will examine your knee and find a bulge in the back of your knee. You may need to have a magnetic resonance image (MRI) to help the healthcare provider determine if you have a Baker's cyst.

How is it treated?

Sometimes the cyst goes away on its own. If the cyst does not cause bothersome symptoms, it may not be treated. To treat this condition:

• Put an ice pack, gel pack, or package of frozen vegetables, wrapped in a cloth on the area every 3 to 4 hours, for up to 20 minutes at a time.
• Raise your knee on a pillow when you sit or lie down.
• Wear an elastic bandage or a sleeve around your knee.
• Take an anti-inflammatory such as ibuprofen, or other medicine as directed by your provider. Nonsteroidal anti-inflammatory medicines (NSAIDs) may cause stomach bleeding and other problems. These risks increase with age. Read the label and take as directed. Unless recommended by your healthcare provider, do not take for more than 10 days.
• The cyst may be drained, or you may have surgery to remove the cyst.

How can a Baker's cyst be prevented?

There is really no way to prevent a Baker's cyst from forming.