Excess knee-joint fluid pushes through the back of the joint capsule, causing a cyst that protrudes into the back area of the knee (popliteal fossa). It is sometimes called a popliteal cyst and causes ...

Pain in the back of the knee, called the popliteal fossa, is common, but there is a wide range of causes, ranging from ligament injury to arthritis.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.

A: A Baker's cyst is a collection of fluid behind the knee. It was named after a British surgeon, William Baker, who described these cysts in the late 1800s. It's sometimes called a popliteal cyst.