Popliteal Cyst (Bakers Cyst)

What is a 'Popliteal Cyst'?

In the hollow bit at the back of the knee is a bursa (a small sack of fluid used to help lubricate the joint). A fairly uncommon condition is when the back of the joint gets swollen and causes the bursa to swell also. Usually some 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. This is Popliteal Cyst.

What are the symptoms?

• A rounded swelling the size of a golf ball.
• A sensation of pressure in the back of the joint which can go down into the calf muscle.
• Difficulties in bending the joint.
• Aching and tenderness 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.

What are the causes of Popliteal Cyst?

• In younger athletes the cause may be a torn cartilage meniscus may be the underlying cause.
• In older athletes arthritis might be suspected as a possible cause.
• Any damage within the knee joint may cause swelling and therefore a Baker's Cyst.

What can the athlete do to help get rid of Popliteal Cyst?

• Rest. The symptoms may disappear by themselves. In children the condition may suddenly clear up. Children undergoing surgery stand a 40% chance of the Popliteal Cyst returning.
• Have a full knee examination to identify the cause of the swelling.
• See a sports injury specialist or doctor.

What can a sports injury specialist or doctor do?

• 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 should be out of action for 8 to 12 weeks following surgery.

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.

Pages:

1. Baker's Cyst
2. Knee ligament examination