What is a Baker cyst?
A Baker cyst is a small, fluid-filled bump which forms on the back of your knee. They develop when something damages your knee joint and extra fluid drains out of your knee. The fluid can only drain in one direction — out the back of your joint. That buildup forms the sac which becomes a Baker cyst.
The most obvious symptom of a Baker cyst is the bump that forms behind your knee.

Other common symptoms include:
Knee Pain
General Knee Stiffness
Trouble bending your knee as far as you usually can (a limited range of motion).
Swelling in your knee joint or on your leg around it.

Anything which damages your knee joint can cause swelling and trigger a Baker cyst. The most common causes are different types of knee arthritis and chronic injuries.

How are Baker cysts treated?
Your Physiotherapist will treat the cause of your Baker cyst rather than the cyst itself. It will usually go away when the damage in your knee has healed. The treatments you’ll need will depend on what knee damage has occurred as shown on X-Ray. Your Physiotherapist will show you specific stretches and strengthening exercises to help your affected knee and whole lower limb.

If your cyst bursts it can be very painful and you will experience the pain travelling down from your knee into your calf muscle.