...less medical jargon in a 'Quick Glance' format!
A Popliteal Cysts (also called Baker's Cyst) is a condition in which you experience a bulge and a feeling of tightness behind your knee. The pain gets worse when you fully extend your knee or when you're active.
This kind of cyst is usually the result of a problem with your knee joint, such as arthritis or a cartilage tear. Both conditions can cause your knee to produce too much fluid, which can lead to a Popliteal cysts. Up to one in five people with other knee problems may develop this cyst.
Although this cyst may cause swelling and make you uncomfortable, treating the probable underlying problem usually provides relief.
In some cases, the cyst causes no pain and may go unnoticed. If you do experience signs and symptoms, you may notice:
Swelling behind your knee, and sometimes in your leg
A door hinge needs oil to swing smoothly, to reduce the friction between its moving parts and to minimize wear and tear. Similarly, the cartilage and tendons in your knees rely on a lubricating fluid called synovial fluid. This fluid helps your legs swing smoothly and reduces friction between the moving parts of your knees.
Synovial fluid circulates throughout your knee and passes in and out of various tissue pouches throughout your knee. A valve-like system exists between your knee joint and the bursa on the back of your knee. This regulates the amount of synovial fluid going in and out of the bursa.
But sometimes the knee produces too much synovial fluid. Most commonly this is caused by an inflammation of the knee joint, such as occurs with various types of arthritis. A knee injury, especially a cartilage tear, also is a common cause of Popliteal cyst.
When the popliteal bursa fills with fluid and expands, the result is a bulge called a Popliteal cyst. In texture, it's similar to a balloon filled with water.
Many times, no treatment is required and the cyst will disappear on its own.
If the cyst is very large and causes a lot of pain, your doctor may use the following treatments:
Icing, a compression wrap, and crutches may help reduce pain and swelling. Gentle range-of-motion and strengthening exercises for the muscles around your knee may also help to reduce your symptoms and preserve knee function.
Your doctor may drain the fluid from the knee joint using a needle. This is called needle aspiration and is often performed under ultrasound guidance.
Your doctor may inject a corticosteroid medication, such as cortisone, into your knee to reduce inflammation. This may relieve pain, but it doesn't always prevent recurrence of the cyst.
Typically though, doctors treat the underlying cause rather than the cyst itself.
If your doctor determines that a cartilage tear is causing the overproduction of synovial fluid, he or she may recommend surgery to remove or repair the torn cartilage.
In some instances, particularly if you have osteoarthritis, the cyst may not go away even after your doctor treats the underlying cause. If the cyst doesn't get better, causes pain and interferes with your ability to bend your knee, or if — in spite of aspirations — fluid in the cyst hinders knee function, you may need to be evaluated for surgery to remove the cyst.