Popliteal Cyst (Baker's Cyst)

What is a Popliteal Cyst?

A Popliteal Cyst is a swelling of the bursa at the back of the knee. This condition is fairly uncommon and is caused by the back of the joint becoming swollen. Often a disorder of the knee causes the synovial (lubricating) fluid within the knee joint to increase. This then spills into the bursa at the back of the knee causing it to increase in size.

What are the symptoms of Baker's Cyst?

• There will be a rounded swelling at the back of the knee .
• Pressure at the back of the joint. This may go down into the calf muscle.
• Difficulty bending the knee.
• It may be tender and ache after exercise.
• If you turn all lights out and shine a torch through the lump you should see a red glow around the lump indicating that it is filled with fluid.

Causes of a Popliteal Cyst:

• Torn cartilage meniscus in younger athletes may be the underlying cause.
• In older athletes arthritis may be a cause.
• Any damage within the knee joint may cause swelling and therefore a Baker's Cyst.

How can the athlete treat a Baker's Cyst?

• Baker's Cyst may disappear by itself so rest is very important.
• Ice, compression and elevation will also help reduce swelling.
• A full knee examination will show the cause of the swelling.
• See a sports injury specialist or doctor.

Visiting a sports injury specialist:

• Find out what causes the swelling in the first place and treat it.
• This could be a cartilage meniscus tear, Osteoarthritis or injury to the kneecap.
• Operate to correct the above or remove the bursa. You would be out of action for 8 to 12 weeks following surgery.

Useful Products:

• Cold therapy products - Applying a cold pack or wrap will help to reduce swelling and pain.
• Knee supports - Wearing a knee support will provide compression to help reduce swelling. If there is associated injury it will alos provide the joint with compression.

Be aware that lumps in the back of the knee are most likely a Popliteal Cyst but might possibly be a tumor or an aneurysm (swelling in an artery). If unsure always seek advise of a therapist or doctor.

Please the Virtual Sports Injury Clinic for more information on how to treat a Popliteal Cyst and other knee injuries.