A baker’s cyst is sometimes called a “popliteal cyst”. A baker’s cyst is a benign swelling found behind the knee. The baker’s cyst lies posterior to the medial femoral condyle. Te cyst is connected to the knee joint through a valvular opening. Knee effusion or swelling from intra-articular pathology allows the fluid to go through the valve to the cysts in one direction (usually behind the knee). Sometimes the patient complains about swelling behind the knee and that alerts the clinician to the possibility of having a problem inside the knee itself. The cyst is located between the semimembranosus and the medial gastrocnemius muscles. The cyst is usually located at or below the joint line.