Pain in the back of the Knee? - Baker's Cyst

Baker’s cyst (popliteal cyst) is a swelling on the back of the knee caused by the build-up of fluid inside sacs called bursae.

The knee is a hinge joint, situated between the femur (thigh) bone & tibia (shin bone). The entire joint is enclosed inside a tough capsule lined with a membrane & filled with lubricating synovial fluid. Extra capsules or sacs of fluid, known as bursae, cushion the joint & help reduce the friction between tissues caused by movement.

Symptoms of a Baker’s cyst

Baker’s cysts may have no symptoms. If symptoms occur, they can include:

• A pronounced soft lump or swelling on the back of the knee
• The lump looks most obvious when the person is standing
• A sensation of pressure in the back of the knee joint
• Persistent pain or aching
• Restricted mobility of the joint
• A sensation of tightness at the back of the knee when the leg is straightened.

What causes a Bakers cyst?

• Arthritis (rheumatoid or osteoarthritis) of the knee joint or patellofemoral joint.
• Torn meniscus (cartilage) in the knee
• Trauma or injury to the knee can cause a build-up of fluid (effusion), which triggers Baker’s cyst.
• Local infection can cause fluid retention around the knee joint.

Treatment for Baker’s cyst
Treatment options for Baker’s cyst can include:

• Physiotherapy is beneficial to manage symptoms & gain advice
• Treatment for the underlying cause can be sought through physiotherapy; and other medical treatments such as medication for arthritis, or surgery for torn knee cartilage.
• Inserting a needle into the cyst & draining off the fluid, but it will often return.
• Cortisone injections
• In severe cases, surgery to remove the cyst entirely

See your Physiotherapist for ways you can help manage the discomfort of a Baker’s cyst.