A Baker’s cyst, or popliteal cyst, is a pocket of fluid that forms behind the knee. Typically caused by arthritis or injury in the knee, this type of cyst forms when excess synovial fluid from the joint is pushed into a small sac of tissue behind the knee.

bakers cyst

In most cases, a Baker’s cyst does not cause the patient significant pain. However, if pain is present, it will usually be minor and may radiate to the upper calf. The pain will be felt when the knee is all the way bent or straightened.

Other symptoms of a Baker’s cyst include swelling behind the knee that gets worse while standing. In addition, it will cause tightness or stiffness behind the knee as well.

At times, the pocket of fluid will rupture and drain into the tissues of the lower leg, which can cause swelling and redness in that part of the leg.

Because symptoms of a Baker’s cyst are similar to those of more serious conditions (blood clots, aneurysms, or tumors), your physician may order one or more imaging tests. These may include X-ray, MRI, or ultrasound testing.

A Baker’s cyst will sometimes go away on its own. If another problem such as arthritis is causing the cyst, your physician may treat the problem, which usually makes the pain and swelling go away. If the cyst is large and painful, the following treatments may be effective:

  • Medication – ibuprofen, naproxen, or corticosteroid injection into the knee may reduce inflammation.
  • Fluid drainage – using a needle to drain the fluid from the knee joint, with the help of ultrasound.
  • Physical therapy – Icing, strengthening exercises, a compression wrap, and crutches may help reduce pain and swelling.
baker's cyst

If your Baker’s cyst is the result of a cartilage tear, your doctor may recommend surgery to remove or repair the torn cartilage. In this situation, adult stem cell therapy may be an alternative to rebuild the damaged tissue.