A cyst is a cyst-like mass that appears in an organ of the body, which contains fluid of different natures, such as sebaceous gland secretions or purulent discharge, which can occur in various parts of the body, and it is benign in itself. Cysts can also develop around the knee, and although there are several causes, the more prominent ones are meniscus cysts and popliteal cysts.
Meniscus cysts most often appear on the inside or outside of the kneeRarely, it can be found on the anterior or posterior side of the kneeGenerally small, a few can become largerUsually associated with a torn meniscus. The meniscus is the C-shaped cartilage in the knee joint that acts as a shock absorber and can cause a meniscus tear when the knee is suddenly twisted or turned. However, older people can tear without injury.
After a meniscus tear, fluid in the joint penetrates through the tear to the outside of the joint capsule, forming a meniscus cyst. Meniscal cysts usually appear as painful lumps on the inside or outside of the knee joint. The fluid inside the cyst is thick and sticky, so the lump is hard to the touch. The size of the cyst changes as fluid continues to flow from the knee joint into the cyst, and if the cyst is large enough to a certain extent, it can be accompanied by arthritis of the knee.
MRI can accurately diagnose meniscal cysts, and meniscal tears can also be seen. Most of the underlying causes of meniscal cysts are related to meniscal tears or arthritis of the knee. If symptoms are mild, try to be conservative** first, including rest, physical**, and anti-inflammatory medications. If the cyst is large and painful, suction alone may not be the solution, and the focus is on meniscus tears and underlying arthritis, which can be surgically repaired to prevent cysts.
Also known as Baker's cyst, it is the most common cause of lumps around the knee. Much more common and larger than meniscus cysts, they are usually located in the "fossa" at the back of the kneeThis is called the popliteal fossa. The popliteal fossa is an important part of the knee joint and plays an important role in the stability and function of the knee joint. The cause of popliteal cysts is related to a variety of factors, which are benign in themselves, but may also be the result of the development of the disease, which is mainly manifested by excessive fluid accumulation in the knee joint due to factors such as inflammation, and part of the fluid is pushed to the back of the knee.
During an attack of osteoarthritis, a popliteal cyst can be felt on the back of the knee, and rheumatoid arthritis and meniscus injuries can also produce too much synovial fluid in the joint, resulting in a popliteal cyst. If the cyst is large enough, it can limit the joint and cause pain, especially when the knee is extended. Popliteal cysts sometimes rupture. Presents with sudden pain and swelling in the lower leg that may be misdiagnosed for a more serious condition, such as deep vein thrombosis.
Ultrasonography is simple and effective in evaluating popliteal cysts. Can confirm the diagnosis and rule out other serious conditions (e.g., deep vein thrombosis). If the mass on ultrasound does not quite resemble a popliteal cyst, further evaluation with MRI may be done. Soft tissue tumors or enlarged arteries in the back of the knee (called popliteal artery aneurysms) can also cause swelling.
The first step of popliteal cyst is usually the method of puncture and injection closure to extract excess fluid, make the cyst smaller, and then seal, which takes a short time, and the patient can generally walk normally after a few days of rest, if it is still **, it is necessary to consider surgical excision, separation along the cyst wall during the operation, try not to break the cyst wall, and peel off the entire cyst completely.
There are other causes of swelling or lumps around the knee. Examples include tumors of bone or soft tissue, but they are rare. If swelling around the knee is found, the examination usually begins with an ultrasound, which is very useful for evaluating soft tissue masses close to **. If you are not sure, an MRI may be necessary. If hyperostosis is suspected, a knee x-ray is also done.
Medical science, for reference only.