Popliteal cyst

The popliteal fossa is a diamond-shaped depression behind the knee joint, which can be clearly palpated when the knee is flexed. A popliteal cyst (Baker's cyst) is a condition caused by an increase in intra-articular fluid and pressure in the knee joint, leading to the extrusion of synovial fluid into the popliteal bursa. It is common in children aged 4-7 years and adults aged 35-75 years. Symptoms include discomfort in the popliteal region, a feeling of fullness after walking, and restricted range of motion of the knee joint.