Baker's cysts in children

What is a Baker’s cyst?

A Baker's cyst is a visible swelling that can form at the back of your child's knee. It occurs when fluid builds up inside the bursa, which is a small sac that works to reduce friction between your child’s calf and knee joint. 

Also known as popliteal cysts, Baker’s cysts are quite common in boys between four to eight years old and they usually occur due to a sports injury or another kind of blow to the knee.

What are the symptoms of a Baker's cyst?

Usually, a child with a cyst will have no symptoms other than a visible lump at the back of their knee. This lump normally goes away on its own. In some cases, a Baker's cyst may lead to other symptoms, like:

• A feeling of tightness behind the knee
• A pain or ache in the calf and/or knee
• Clicking or locking in the knee joint
• Fluid leaking down the knee

How is a Baker's cyst diagnosed?

Your child’s consultant will usually be able to make a diagnosis by discussing their symptoms and examining the cyst.

They will let you know if they need to carry out further tests – such as an MRI or ultrasound scan – to rule out other conditions.