Pain in the hollow of the knee

Introduction – Pain in the hollow of the knee

Pain in the hollow of the knee is a common complaint in all age groups. The most common causes include sports injuries and signs of wear and tear of the knee joint. Less frequent, but particularly dangerous or severe, are leg vein thromboses and slipped discs. If the complaints are so protracted or intense that they require a visit to the doctor, the doctor can make a tentative diagnosis by asking about various circumstances (the patient’s sports habits, time of onset and exact localization of the pain) and by means of physical function tests.

• Pulling in the hollow of the knee – Is that dangerous?

Causes of pain in the hollow of the knee

The possible triggers of pain in the hollow of the knee can be divided into traumatic (injury-related), degenerative (wear-related) and internal (internal causes). Injury-related causes are the most common triggers for popliteal pain in younger patients. The pain usually occurs suddenly and in connection with an unfavorable movement in the knee joint, for example during sports.

The more clearly the knee pain is limited to the region of the popliteal fossa, the stronger the suspicion of damage to one or both menisci in the knee joint. The menisci are buffer disks made of cartilage that can be affected by twisting or compression of the knee. Depending on the affected meniscus (there is an inner and outer one in each knee), the pain is felt at the inner or outer hollow of the knee.

Wear-related popliteal pain is more likely to occur in older patients. The most common trigger here is the so-called Baker cyst. This is a sac of the joint capsule filled with synovial fluid, which can develop when the knee joint is continuously irritated (for example, due to arthrosis or unusually high sporting activity).

and Baker’s cyst. The most important internal cause is thrombosis of the leg veins, which, although it is extremely rare, is the trigger for popliteal pain, it should at least be in the back of the head because of its dangerous nature. Here, the interplay of various factors (prolonged immobilization, e.g. in an airplane, taking contraceptives, genetic predisposition, etc.)

causes blood to coagulate in the leg veins, and the popliteal fossa is one of the most frequent sites for this event. In the worst case, this clot can be washed out to the lungs and lead to a pulmonary embolism. Other rarer causes of pain in the popliteal fossa include anatomically induced compression of the popliteal nerve or popliteal artery, tendonitis of the posterior thigh muscle or a herniated disc.

and symptoms of a herniated disc. Many structures that supply the calf pass through the hollow of the knee. For example, the blood supply from the thigh continues through the popliteal artery into the lower leg.

If blood clots form in the vessels, the pain can travel from the popliteal artery to the calf. Nerves responsible for the calf also pass through the popliteal fossa and can therefore cause such pain. The calf muscles also have a starting point in the hollow of the knee.

Overloading or injuries to the hollow of the knee can therefore also affect the calf muscles, which also causes pain that moves from the hollow of the knee to the calf. You can find more information about pain in the calf under Pain in the calf and in the hollow of the kneeWhen sitting, the knee joint is usually bent by about 90°. This should not normally cause pain.

However, the structures of the hollow of the knee (especially nerves and vessels) can be bent by the flexion. This can cause pain in the hollow of the knee. This often occurs when, for example, the edge of a chair has pressed on the hollow of the knee when sitting.

Sitting cross-legged can also cause such problems, as the greater flexion in the knee joint also causes greater pressure on the hollow of the knee. If the complaints in the hollow of the knee occur after exercise, the cause is often muscular. People who are not very well trained can, for example, overstrain their muscles due to a sudden increase in sporting activity.

This can lead to sore muscles or reactive inflammation of the muscles, for example. Injuries can also cause pain in the hollow of the knee. Many muscles converge in the hollow of the knee.These are muscles from the calf as well as muscles from the back of the thigh. For example, pain in the hollow of the knee after exercise can be caused by both the upper and lower leg. What injuries can occur during sports?