A Baker’s cyst is a swelling in the space behind the knee. It has nothing to do with baking. The condition is named after a British surgeon, Dr. William Morrant Baker. In the late 19th century, Dr. Baker documented cases of swelling in the popliteal region, the depression in the back of the knee joint, hypothesizing that it was a result of synovial membrane herniation and cyst formation due to osteoarthritis.
Synovial fluid lubricates the knee to help the leg move and reduces friction between all of the moving parts of the knee. A Baker’s or popliteal cyst is a synovial fluid filled cyst that develops behind the knee. It is usually the result of knee joint conditions, such as arthritis, torn cartilage, and gout, that cause the knee to produce excess lubricating fluid. Baker’s cyst symptoms include a bulge in the back of the knee, knee joint locking or popping, and knee and calf pain. The symptoms are similar to a blood clot, aneurysm or tumor in the leg. So it is important to rule out a serious cause of your symptoms.
Usually Baker’s cysts can be resolved by some self-care techniques such as icepacks, rest, compression bandages, and non-steroidal anti-inflammatory medications. If the swelling is particularly large and painful, other treatments include:
- A corticosteroid injection to reduce inflammation and relieve pain
- Physical therapy to strengthen knee muscles
- Fluid drainage via needle aspiration
- Arthroscopy surgery to remove the cyst and repair the joint
If the underlying cause of the Baker’s cyst, as determined by a physical exam by the DOC orthopedic surgeon or PA and imaging tests, X-rays or MRI, is a cartilage tear that is causing overproduction of synovial fluid, surgical intervention may be needed to repair the torn cartilage.