Introduction
Pain behind the kneecap is a relatively unspecific symptom and cannot be clearly assigned to a disease. The pain is often a sign of overloading or increasing wear and tear due to increased cartilage wear. Radiological imaging is often necessary for the doctor to make a reliable diagnosis.
The causes
The patella is exposed to great forces during physical exertion, so that it is possible that this may lead to cartilage damage behind the patella in the long term and that even parts of the cartilage are rejected. This cartilage damage occurs mainly in athletes due to the great strain. In addition to cartilage damage, overloading can also lead to patellar tip syndrome – an inflammation of the patellar tendon.
In addition to sporting overloading, traumas or anatomical deviations (e.g. hip malpositions or knock-knees) can also lead to cartilage damage. The cartilage behind the patella serves as a buffer and thus reduces the forces acting on the knee joint. If cartilage damage is present, a so-called patellofemoral pain syndrome often occurs.
Furthermore, the so-called plica syndrome can also cause pain. Within the knee, there are several folds (plicae) of the joint mucosa. If such a wrinkle thickens, e.g. in the course of an inflammation, pain and restricted movement are usually the result.
In addition, behind the patella there is an accumulation of fat, which is called Hoffa’s fat body. When falling on the knee, this fat body can tear or become inflamed when overstrained. In both cases there is a stabbing pain behind the kneecap.
With increasing age, bone degeneration also occurs. Retropatellar arthrosis can develop in the area of the knee. Not infrequently, however, the pain can already occur in adolescence.
This is caused by rapid growth, which changes the direction of the patellar tendon and the thigh muscle responsible for knee extension is not yet strong enough. This is usually remedied by targeted training of this muscle. One cause of pain behind the kneecap can be a so-called knee joint effusion.
This is an accumulation of fluid behind the kneecap within the joint capsule. The fluid can be synovial fluid, pus or even blood. Such effusions are caused in various ways.
A frequent cause is ligament injuries in the knee area, for example a torn cruciate ligament. A dislocated kneecap or arthrosis, which is often found in older people, are also typical causes of knee joint effusions. The effusion leads to swelling of the knee, which is often accompanied by limited mobility and pain.
In addition, redness in the area of the knee can occur. The knee joint effusion can be diagnosed by simple examinations. A possible diagnosis is then called “dancing patella” or “dancing kneecap”.
If a “dancing patella” is diagnosed, the affected knee should be protected and positioned as high as possible. Knee joint effusion – How dangerous is it? The kneecap (patella) is the third joint partner of the knee joint, along with the femur and tibia.
It is of decisive importance in cases of heavy strain on the knee as well as in movements of the legs. Between the kneecap and the thigh bone there is joint cartilage. This cartilage is increasingly worn down through movement and pressure.
When the cartilage is completely worn away, the two bones lie directly on top of each other. This condition is then called knee arthrosis. It is usually associated with severe pain.
The kneecap is put under a lot of strain by exerting pressure on the patella, for example when working on the knees, or by general heavy strain on the knee, for example when lifting heavy loads. If the load is applied permanently, this can lead to arthrosis of the patella. Knee arthrosis can also have anatomical causes.
For example, if the patella and thigh bone do not fit properly, friction can occur, which ultimately leads to arthrosis. Runners in particular are at risk of developing knee arthrosis due to their heavy strain and movement of the knee. Knee pain can occur during or after sporting activities, especially after jogging.
These can have different causes. Typical causes are muscular imbalances of the thigh muscles, congenital leg malpositions (so-called “bow legs” or “knock knees”) or instabilities of the hip and ankle joints.In addition, an incorrect running style can also lead to pain behind the kneecap. For example, if you bend your knee too much when jogging and thus exert increased pressure on the kneecap, this can cause inflammation of the cartilage underneath the kneecap.
This inflammation finally leads to a strong feeling of pain behind the kneecap and should be treated with a gentle posture. Patellar tendon inflammation is called patellar tip syndrome. The patellar tendon runs from the lower edge of the patella to the upper edge of the tibia.
Inflammation of the patellar tendon is usually caused by an increased or unusual tensile load on the tendon. Such inflammation often occurs in jump-intensive sports such as volleyball or basketball as well as in long-distance runners. The patellar tendon syndrome can take on different dimensions and is therefore also divided into four degrees.
Depending on the degree, the symptoms occur at rest or only when the patient is under stress. The inflammation of the tendon is usually treated conservatively, i.e. without surgery. Physiotherapy, massages, bandages, stretching exercises as well as medication and ointments can improve the symptoms.
Sinding-Larson’s disease is a synonym for patellar tip syndrome. However, the term refers to the inflammation of the patellar tendon, especially in children and adolescents. This inflammation or injury of the tendon often occurs during the course of growth.
During growth, small tears can develop in the tendon and thus cause inflammation, which ultimately stimulates cartilage growth. The resulting pain emanates from the tendon attachment of the lower patella. You can find more information about Sinding-Larson’s disease here.
