A Baker’s cyst is a painful swelling at the back of the knee, usually caused by problems within the knee joint or the tissues behind it. It can affect any age group, although it’s more common in people over the age of 40, particularly women.

How is it caused?

Treating the underlying cause can often result in the cyst disappearing. Causes include:

• Osteoarthritis (the most common cause)
• Sports injuries
• A blow to the knee
• Rheumatoid arthritis
• Gout

What are the symptoms?

• The cyst can cause pain, a build-up of fluid, and a sense of fullness at the back of the knee
• Rarely, the cyst can burst, causing pain and swelling in the calf

How is it diagnosed?

A diagnosis made during a medical examination can be backed up with an ultrasound or MRI scan.

How is it treated?

Non operative treatment: rest, compression bandages (available from your local pharmacy), and anti-inflammatory medication (if advised by your doctor) can help reduce the swelling, along with applying ice regularly to reduce the swelling. It’s important not to apply the ice directly to the skin as this can result in a burn from the ice. The best method is to wrap some crushed ice or frozen peas in a towel and place onto the swollen area for around 20 minutes, four times a day, until the swelling goes down. It is, however, important that the cause of the cyst is also treated.

Surgery: in some cases you may be offered surgery to drain or remove the cyst.

Important: This information is only a guideline to help you understand your treatment and what to expect. Everyone is different and your rehabilitation may be quicker or slower than other people’s. Please contact us for advice if you’re worried about any aspect of your health or recovery.