Please help WikiDoc by adding more content here. It’s easy! Click here to learn about editing.

A Baker’s cyst, otherwise known as a popliteal cyst, is a benign swelling found behind the knee joint.

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

It is named after the surgeon who first described it, Dr. William Morrant Baker (1839-1896).^[1]

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

In adults, Baker’s cysts usually arise from almost any form of knee arthritis and cartilage (particularly the meniscus) tear. Baker’s cysts in children do not point to underlying joint disease. Baker’s cysts arise between the tendons of the medial head of the gastrocnemius and the semimembranosus muscles. They are posterior to the medial femoral condyle.

The synovial sack of the knee joint can, under certain circumstances, produce a posterior bulge, into the popliteal space, the space behind the knee. When this bulge becomes large enough, it becomes palpable and cystic. Most Baker’s cysts maintain this direct communication with the synovial cavity of the knee, but sometimes, the new cyst pinches off. A Baker’s cyst can rupture and produce acute pain behind the knee and in the calf and swelling of the calf muscles.

As a summary:

• A popliteal cyst is fluid distention of a bursa between the gastrocnemius and semimembranosus tendons via a communication with the knee joint.
• Fluid within a Baker’s cyst may communicate freely with the knee joint. However, the presence of a valvelike mechanism may allow joint fluid to communicate in only one direction.
• Popliteal cysts may be seen with many joint abnormalities, such as internal derangement, osteoarthrosis, or inflammatory arthritis; the most common associations include joint effusion, meniscal tear, and degenerative joint disease.

A Baker’s cyst is caused by swelling in the knee. The swelling is due to an increase in synovial fluid – the fluid that lubricates the knee joint. When pressure builds up, fluid bulges into the back of the knee.

Baker’s cyst commonly occurs with:

• A tear in the meniscal cartilage of the knee
• Knee arthritis (in older adults)
• Rheumatoid arthritis
• Other knee problems

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

People with knee problems such as a meniscus tear or arthritis are at higher risk for a Baker’s cyst.

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.

Please help WikiDoc by adding more content here. It’s easy! Click here to learn about editing.

A Baker’s cyst will not cause any long-term harm, but it can be annoying and painful. The symptoms of Baker’s cysts usually come and go.

Long-term disability is rare. Most people improve with time or arthroscopic surgery.

Complications are unusual, but may include:

• Long-term pain and swelling
• Complications from related injuries, like meniscal tears

Please help WikiDoc by adding content here. It’s easy! Click here to learn about editing.