Synonyms: Baker Cyst, Popliteal Cyst, Synovial Cyst
Definition
The popliteal cyst is a protrusion of the posterior capsule of the knee joint as a result of increased pressure in the knee joint (joint effusion).
Creation
The popliteal cyst or Baker’s cyst is not to be understood as a disease, but much more as a symptom of irritation and an increase in pressure in the knee. Since the popliteal cyst or the posterior joint capsule is directly connected to the joint space, the cyst can take on different dimensions depending on the production of synovial fluid. Due to its multiple causes, which are generally frequent, the popliteal cyst also occurs more frequently. The probability of a popliteal cyst increases with age, but it can generally occur in any generation.
Symptoms
Cysts of the popliteal fossa can occur on one or both sides (e.g. in rheumatism or arthrosis). A popliteal cyst is not always noticed by the patient himself/herself, especially when it occurs as an accompaniment to painful injuries. People with popliteal cysts can be free of complaints or sometimes complain about pain in the popliteal fossa that cannot be localized exactly and radiates into the adjacent thigh or calf.
In most cases, a bulging, elastic bump can be palpated, which increases in size depending on the load and can shrink after several days of rest to such an extent that it can no longer be palpated. With the swelling of the popliteal cyst, an increasing swelling of the entire knee joint is often noticed. Depending on the pressure, the popliteal cyst can press on nerves, veins and arteries in the hollow of the knee, resulting in swelling, circulatory problems, restricted mobility and numbness in the calf and foot.
In the case of severe swelling of the popliteal cyst, the wall of the joint capsule can become thin and burst. In this case, the synovial fluid spreads into the surrounding tissue and swelling can occur from the foot to the calf. Often, a bang is felt in the hollow of the knee at the moment of bursting. A conceivable complication of a very pronounced popliteal cyst is a compartment syndrome.
