A popliteal cyst or Baker’s cyst is a swelling filled with fluid that result to the formation of a protuberance at the rear part of the knee, resulting to tight and limited movement. The cyst is also painful if the individual extends or bends the knee. In most cases, the condition is due to a problem that affects the knee joint such as cartilage injury or arthritis. Understandably, treating the underlying cause can help alleviate the problem. Additionally, a popliteal cyst will not cause any long-term damage but it can cause discomfort.
Causes of a popliteal cyst
The severe swelling of the knee can cause the formation of a popliteal cyst. This swelling is the result of excess synovial fluid. The synovial fluid is a clear liquid that circulates via the cavities in the knee joint. In some cases, the knee generates excessive amounts. As the pressure increases, the fluid is forced back to the knee, resulting to a bulge. The most common causes of a popliteal cyst include:
- Arthritis of the knee
- Knee cartilage damage
- Rheumatoid arthritis
- Other knee conditions that involve inflammation of the joint
Since the knee is considered complex, it is prone to injuries. Knee injuries can cause inflammation that will eventually lead to the formation of a popliteal cyst.
Symptoms of a popliteal cyst
The symptoms of a popliteal cyst include the following:
- Mild to severe pain
- Diminished range of motion
- Swelling behind the knee and calf
- Bruising on the knee and calf
- Rupture of the cyst
The bruising and swelling behind the knee and on the back of the calf can be caused by a blood clot. It is vital to have it checked by a doctor to determine if the cause is a clot or a cyst. An ultrasound or MRI can be performed to help with a diagnosis.
Treatment for a popliteal cyst
In most cases, a popliteal cyst does not require any treatment and will go away on its own. Nevertheless, if the swelling becomes large and causes severe pain, the doctor will recommend the following treatment options.
Drainage of fluid involves the insertion of a needle into the swelling. An ultrasound is used to guide the needle in the correct location and then withdraw the excess fluid from the joint.
Gentle, regular exercises can help increase the range of motion as well as strengthen the muscle surrounding the knee. The doctor can recommend crutches to help alleviate the pain. You can also reduce the pain by using a compression wrap or applying an ice pack on the affected joint. Ice has been used as a treatment option for injuries that you can learn by taking part in a first aid course.
When it comes to medications, the doctor will recommend a corticosteroid medication for the cyst. Even though it can help reduce the pain, it will not continuously prevent a popliteal cyst from developing again. In most cases, the doctor will treat the primary cause of the cyst instead than the actual cyst. If there is damage to the cartilage, the doctor will recommend surgery to repair or remove it.