In most instances, the primary cause of the Baker’s cyst is not the popliteal fossa or bursa at all but rather inflammation elsewhere in the knees such as that due to a meniscus tear or arthritis.

Image caption, The popliteal fossa is the hollow space at the back of the leg, behind the knee The popliteal fossa is the diamond-shaped space you find at the back of your knee, formed between the ...