A Baker's cyst (also known as a popliteal cyst) is a fluctuant swelling located in the popliteal space. The term is a misnomer, as the swelling is the result of synovial fluid distending the gastrocnemio-semimembranosus bursa, rather than being a true cyst. In older patients it is commonly part of a chronic knee joint effusion which herniates between the two heads of the gastrocnemius and is most commonly secondary to degenerative or meniscal pathology.
This is a companion discussion topic for the original article at https://patient.info/doctor/orthopaedics/bakers-cyst-pro