Definition
Behind the swelling of the hollow of the knee, there are numerous, different clinical pictures hidden, which have different causes and bring along different accompanying symptoms. What causes the complaints depends on many factors, such as various underlying diseases, accidents, lifestyle, age and gender. Depending on the cause, swelling can be the only symptom or it can be accompanied by pain, signs of inflammation, joint stiffness. Accordingly, the diagnosis and treatment of the swollen hollow of the knee are also highly variable.
Causes
The causes of the swollen popliteal fossa depend on the age, sex and living conditions of the patient. Frequently, overloading or incorrect loading of the knee triggers the swelling. The swelling is then usually relieved by rest.
After accidents and falls, ligaments, cartilage, bones or the capsule of the knee joint may be damaged, which also results in swelling. A permanent swelling, which may be associated with pain, may indicate a Baker cyst, i.e. a fluid-filled sac in the joint capsule. This is often the result of a previous rheumatic illness and tends to affect older people.
A dreaded cause is thrombosis of the deep leg veins: This mainly affects women, can cause severe pain and lead to dangerous complications. In rare cases, and especially in older men, a so-called poplietal aneurysm can be considered for the swelling of the hollow of the knee. This is a bagging of the artery that runs through the hollow of the knee.
A thrombosis is a blood clot that is deposited in a vein and clogs it. Thromboses often form in the legs because the blood “sinks” in standing and sitting; thromboses in the deep-lying veins of the legs are more relevant here than those in the superficial skin veins (phlebothrombosis). The risk of suffering a thrombosis is increased by prolonged immobility, e.g. by sitting for long periods while travelling or wearing a plaster cast on the leg.
Smoking, especially when taking the pill at the same time, being overweight, and a higher age also increase the risk of thrombosis. Women are affected significantly more often than men. It is important to recognize a thrombosis and treat it if necessary, as it can lead to serious complications: If the clot dissolves, it is washed away with the bloodstream and can then block a blood vessel in the lung, more rarely in the heart or brain. If you suspect a thrombosis, you should therefore consult a doctor immediately.
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