Baker’s cyst is a fluid-filled growth behind the knee that leads to a bulge and a sensation of tightness in the area. Also known as a popliteal cyst, the condition can cause pain that worsens when one straightens or bends their leg. The cyst usually develops as a result of an issue with the knee joint, like an injury, cartilage tear, or arthritis, making the knee produce too much fluid.

Symptoms
A Baker’s cyst may not cause pain in the initial stages, making it remain unnoticed until the condition worsens. When it does, one may experience the following symptoms:

• Knee pain
• Swelling behind the knee
• Swelling in the leg
• Discomfort while moving
• Inability to move the knee and stiffness in the knee
• A fluid-filled lump behind the knee

The symptoms can worsen after physical activities or if one has been standing for a long time. Sometimes, the condition can cause swelling and redness in the lower leg that might look like a blood clot. If one notices any such symptoms, they should consult a doctor immediately and seek treatment.

Causes
A lubricating substance in the joints, known as synovial fluid, allows the leg to swing smoothly. It also helps reduce friction between the moving parts of the knee. But due to some underlying conditions, the knee can start producing too much synovial fluid, which can begin accumulating in the back of the knee. This leads to a Baker cyst. The triggers could be:

• A knee injury, like a cartilage tear
• Direct damage to the knee, like in the case of a ligament fracture or meniscus tear
• Gout
• Inflammation of the knee joint due to arthritis

When the structures around the joint get damaged, the knee starts producing extra fluid that flows only in one direction, leading to a formation of a cyst behind the knee.

Diagnosis
First, the doctor carries out a physical examination to confirm the presence of a cyst. A few symptoms of Baker’s cyst resemble those of other conditions like a blood clot, tumor, and even aneurysm. So, the doctor has to rule out other underlying causes. For which, they may opt for the following tests:

Ultrasound: This test uses sound waves to determine if there is a lump.

X-ray: This is used to check if one has arthritis.

MRI or magnetic resonance imaging: Here, magnetic waves show detailed images of the internal body. This test gives the doctor a clear picture of the underlying cause.

Examination of medical history: The doctor may ask one about previous injuries on the knee and other existing conditions to confirm the cause.

Treatment
The treatment begins with nonsurgical options. The most common option used to soothe swelling and prevent joint damage is the RICE method, i.e., rest, ice, compression, and elevation method. Here is what the doctor may recommend:

Non-surgical treatment: The doctor might recommend starting with lifestyle changes and remedies for Baker’s cyst. Here are a few things one can try to relieve the symptoms:

• Resting the leg whenever possible
• Applying ice to the knee
• Elevating the legs while resting
• Using compression wraps for the knee to reduce the joint swelling
• Taking anti-inflammatory prescription options
• Maintaining a healthy body mass to reduce the pressure on joints
• Using a crutch while walking
• Avoiding activities that put pressure on the knee
• Getting physical therapy to help strengthen the body and knee

Surgical treatment: Surgery is usually the last option to treat Baker’s cysts, so it is recommended when non-surgical treatment fails. The procedure here helps address the source of knee damage. A healthcare provider suggests surgical procedures only when one experiences severe knee pain and is unable to move the knees at all. Here are a few options one can try:

Cyst draining: Here, with the help of a needle, the fluid is drained from the cyst.

Knee osteotomy: A part of the bone is cut to fix the damage to the knee.

Arthroscopic knee surgery: This procedure can help diagnose and treat the condition. Here, the surgeon makes a small cut in the knee and inserts a device called an arthroscope that has a camera at one end. This is known as knee scoping.

If one notices a lump, swelling, pain, or any other signs of the cyst at the back of the knee, they should get it examined by a doctor. A Baker’s cyst can go away on its own and might not always cause pain. However, one should get a checkup if they notice any of the abovementioned signs.