A swelling filled with synovial fluid, at the back of the knee, caused by weakness of the joint membrane [Described 1877. After William Morrant Baker (1838-96), member of staff, at St Bartholomew’s Hospital, London, UK.]
A collection of fluid in the synovium of the popliteal fossa behind the knee.
An inflamed and swollen membrane-lined sac, called a bursa, which is located behind the knee. A Baker cyst can be very painful and may involve extensive swelling that spreads down the back of the leg into the calf and ankle. In its normal state, a bursa is flat and contains very little fluid; it functions as a cushion between bones and soft tissues, such as muscles, ten¬ dons, ligaments, and skin. A Baker cyst, which is caused by inflammation of the main muscle in the calf and the knee joint, may be due to overuse, injury, infection, or arthritis.
A synovial cyst (pouch) arising from the synovial lining of the knee. It occurs in the popliteal fossa.
A Baker’s cyst is characterized as a firm and fluid-filled mass located at the back of the knee. This cyst develops when there is heightened pressure within the knee joint caused by an accumulation of fluid. Such fluid buildup is commonly associated with conditions like rheumatoid arthritis. The cyst itself is formed when the synovial membrane, which covers the knee joint, protrudes backward in a ballooning manner.
The majority of Baker’s cysts are devoid of pain, and certain cysts may even resolve on their own, albeit it may take several months for this to occur. However, in some cases, a cyst can rupture, leading to the leakage of fluid between the layers of the calf muscles. This can result in pain and swelling in the calf region, which can resemble the symptoms of deep vein thrombosis.
The diagnosis of a Baker’s cyst is typically established through the use of ultrasound scanning. Treatment is generally unnecessary, as most cases do not require intervention. However, in certain instances, surgery may be recommended as a treatment option.