Ask The Expert
February 08, 2011
A Bakerís 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. Itís sometimes called a popliteal cyst. They can be found based on symptoms and a physical examination, but ultrasound or MRI testing can confirm the diagnosis.
Bakerís Cysts usually develop due to a problem in the knee that causes joint fluid to accumulate in the joint. This collection of fluid causes pressure to build. When the pressure in the joint is high enough, fluid is forced backwards to form a cyst behind the knee. The anatomy of the knee "traps" the fluid behind the knee; the fluid cannot easily return to the joint.
Eventually, the cyst can become large enough to restrict movement of the knee or cause pain. It can also block the flow of blood through veins behind the knee, causing the lower leg to swell. This can mimic a blood clot in a leg vein. A Bakerís Cyst can also rupture, spilling fluid into the calf. This is also a cause of leg swelling that can mimic a blood clot.
The best way to treat a Bakerís Cyst depends on the reason it developed in the first place. Options for treatment include:
Removing the fluid from the knee and injecting a steroid
If youíve been diagnosed with a Bakerís Cyst, talk to your doctor about the most likely cause and the appropriate treatment options.