Pain in the kneecap


At the kneecap (lat. patella) is a flat, disc-shaped, bony structure located just in front of the knee joint. As in the tendon of the four-headed thigh muscle (lat. Quadriceps femoris muscle) embedded bone, the kneecap is involved in the formation of the articular surfaces of the knee joint. The main task of the kneecap is to protect the knee joint. In addition, the kneecap serves to increase the force development of the four-headed thigh muscle by extending the lever arm. Pain phenomena can often occur in the area of ​​the kneecap (especially in young women). Compared to other joints, the knee joint and / or the kneecap cause problems for many people. Around every second person complains of pain in the front knee (kneecap pain) at least once in their life. Kneecap pain can not only be observed in older people, but often in childhood and adolescence.

Most common causes

Often, pain in the area of ​​the kneecap occurs as a result of direct excessive or incorrect loading of this bony structure. Sports activities, strenuous physical work and poor posture can be the cause. In addition, it can be observed that especially overweight people often suffer from pain in the kneecap. One of the most common causes of pain in the area of ​​the kneecap is the so-called “unstable kneecap”, which is characterized by slipping out to the side (Latin for dislocation).

Furthermore, it can be determined in everyday clinical practice that pronounced cartilage damage and valgus malalignments can lead to kneecap pain. Especially older women (> 50 years) are often affected by such cartilage damage. Reasons for their development are knee osteoarthritis, injuries and genetically determined cartilage weaknesses. The kneecap arthrosis (synonym: Retropatellar arthrosis) itself is one of the most commonly observed causes of pain that is mainly localized behind the kneecap.

Read more on the topic: Pain behind the kneecap

In many cases, other orthopedic diseases also affect the stability of the knee joint and the kneecap. In this context, pain in the kneecap can be observed when there is increased external rotation of the thigh or shin due to the disease.

Likewise, patients with misalignments of the leg axis or the lifting of the arch of the foot (so-called flat feet) increasingly complain of pain in the kneecap area. Since the bony kneecap, by lengthening the lever arm of the quadriceps femoris muscle, contributes to a multiplication of its force development, kneecap pain can also be provoked by muscular disorders in the thigh.

In perfectly healthy people, such pain phenomena are often triggered by temporary overloading of the knee joint, for example by too high a training intensity. Sharp, bright pain that is observed acutely after a dislocation of the kneecap may indicate the presence of a patellar fracture (fracture of the kneecap). Affected patients report in particular the occurrence of severe symptoms after going down the stairs. In addition, a painful stimulus can be provoked by moving the kneecap (so-called displacement pain).

In addition, pain in the area of ​​the kneecap can be observed more frequently in people who often sit with the knee bent for a long time.

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My name is dr. Nicolas Gumpert. I am a specialist in orthopedics and the founder of .
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The knee joint is one of the joints with the greatest stress.

Therefore, the treatment of the knee joint (e.g. meniscus tear, cartilage damage, cruciate ligament damage, runner's knee, etc.) requires a lot of experience.
I treat a wide variety of knee diseases in a conservative way.
The aim of any treatment is treatment without surgery.

Which therapy achieves the best results in the long term can only be determined after looking at all of the information (Examination, X-ray, ultrasound, MRI, etc.) be assessed.

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Kneecap jumped out

Acute trauma can cause the kneecap to jump out of its guide groove on the thigh bone. The kneecap usually shifts outwards. This often damages the back of the kneecap or part of the thigh bone. Retaining straps and capsule apparatus can also tear. All of this leads to pain in the kneecap.

It can also lead to bleeding and water retention. This causes restricted mobility and further pain. Anyone who has a loose ligamentous apparatus must expect the kneecap to pop out more often. The more frequently this happens, the more pronounced the damage to the cartilage on the kneecap and the thigh bone in particular.

Read more on the topic:

  • Joint effusion
  • Capsule tear
  • Therapy of a dislocation of the kneecap

Kneecap arthrosis (synonym: retropatellar arthrosis)

The so-called kneecap arthrosis occurs when the cartilage surface on the back of the kneecap is worn away. It can occur in the context of general knee osteoarthritis or in isolation. Symptoms such as stabbing pain behind the kneecap usually arise slowly and increase over time.

Read more on the topic: Knee osteoarthritis when must be operated

On the one hand, older people (> 50 years of age) are affected, the causes here are mostly degenerative joint changes or injuries from falls.

On the other hand, young people can also be affected, the causes here are often injuries / accidents, broken kneecaps, hereditary cartilage weakness or anatomical malpositions.

Read more on the topic: If one

Jumpers knee (synonym: jumpers knee, patellar tip syndrome)

The jumper's knee, also known as the patellar tip syndrome, is caused by excessive or incorrect loading of the kneecap and quadriceps vision as well as the lower end of the kneecap. The cause can also be an inflammation of the kneecaps or Inflammation of the quadriceps tendon be. Stinging pain also occurs gradually, whereby the pain usually occurs directly during or after physical activity. Mainly active people are affected (volleyball players, basketball players, long jumpers and high jumpers).

Sinding-Larsen's disease

In Sinding-Larsen's (-Johannson's) disease, the lower part of the kneecap is affected by an overload reaction. Often athletes (especially from stop-and-go sports such as basketball, badminton, etc. but also running sports) fall ill with Sinding-Larsen's disease.

Overloading the knee joint, or more precisely the patellar tendon, leads to an inflammatory reaction. This spreads at the base of the patellar tendon on the kneecap, i.e. at the lower pole. In advanced stages, parts of the bones can detach from the kneecap and die.

Read more on the topic: Patellar tip syndrome

Pes anserinus attachment tendinosis (synonym: Enthsopathy of the Pes anserinus)

Pes anserinus attachment tendinosis is tendinitis on the inside of the lower leg just below the knee. Pain often occurs in the morning and is stress-dependent and has a pulling / stabbing character. Mostly athletes, especially runners, as well as people who have had knee prostheses are affected.

Read more on the topic:

  • Rehabilitation after a knee prosthesis
  • Prosthetic knee and sports

Bursitis (synonym: prepatellar bursitis, infrapatellar bursitis)

In the area of ​​the kneecap there are various bursa, on the one hand above the kneecap (B. prepatellar nerve), as well as along the patellar tendon (B. infrapatellaris). Bursae are fluid-filled pads that reduce friction and pressure on the joints. If germs get into the joint through external injuries, more fluid is formed.

The knee joint swells, the skin is tense and overheated. Pressure pain is to be triggered over the affected bursa. Furthermore, mobility in the knee joint is restricted. Jokes occur depending on the load and are of a piercing character.

Read more on the topic: Bursitis on the knee

Patellofemoral pain syndrome (synonym: FPS, CPP, Chondropathiae patellae)

Patellofemoral pain syndrome refers to pain between the kneecap and thigh muscles, as well as around the kneecap, which cannot be precisely assigned. The pain occurs mainly when climbing stairs, after sitting for a long time or during physical activity. But it can also lead to pain at rest.

The causes are overloading of the cartilage, underdevelopment of the kneecap or the kneecap bearing (Patellar dysplasia), too tight kneecap guidance, improper loading due to knock knees, muscular causes (shortened or weakened thigh muscles).

Young people and athletes are particularly affected.

Read more on the topic:

  • Leg muscle training - exercises for strong legs
  • Exercises for knee school


Pain above the kneecap

Above the kneecap, pain is usually caused by the thigh muscles. The quadriceps muscle or its tendon is affected. Here, too, there is very rarely a traumatic (tear) tear. More often than not, there is inflammation caused by overuse, which can affect both the muscle and the tendon and the kneecap. Chronic inflammation can damage the tendon and kneecap to such an extent that it tears the tendon or small pieces of bone loosen from the kneecap and then die.

Read more on the topic:

  • Pain above the kneecap
  • Patellofemoral pain syndrome

Pain below the kneecap

Pain below the kneecap is mostly due to the patellar tendon. This can tear through severe trauma or tear through completely. However, this occurs very rarely.

Read more on the topic: Patellar tendon pain - causes and treatment

Overload symptoms are more common through continuous stress. It often affects people who work a lot on their knees (roofers, tilers, other craftsmen, etc.). Kneeling too much causes constant irritation of the patellar tendon and the lower part of the kneecap.

Read more on the topic: Patellar tip syndrome

Diseases associated with damage to the bones can also cause pain below the kneecap. This includes Sinding-Larsen's disease (Patellar tendon and kneecap) and Osgood-Schlatter disease (Patellar tendon and tibial head).

Read more on the topic: Treatment of Osgood-Schlatter disease such as Burning in the knee

Pain behind the kneecap

Behind the kneecap, pain usually occurs from injuries to the kneecap or thighbone. Such damage can result from the kneecap jumping out, for example. But also patellar lateralization, in which the kneecap is slightly shifted outwards, can cause such damage.

Due to the acute stress or the displacement of the kneecap, the two cartilage layers of the thigh bone and the kneecap no longer sit on top of each other. Instead, bare bone rubs against the cartilage layer of the other bone. This leads to rapid wear and tear on the cartilage and damage to the bone. Both cause pain behind the kneecap.

Pain when climbing stairs

When climbing stairs, there is a special pressure on the knee joint. If you climb the stairs, the quadriceps muscle, i.e. the knee extensor, has to work in particular. Because the quadriceps tendon attaches to the kneecap, inflammation and injury to the tendon and the upper pole of the kneecap can cause pain when climbing stairs.

Read more on the topic: Patellofemoral pain syndrome

When descending the stairs, the pressure is also on the front part of the knee joint. The symptoms often occur more frequently below the kneecap.

Read more on the topic: Patellar tip syndrome

Pain when cycling

Cycling is one of the knee-friendly sports. The continuous movement strengthens the muscles and moves the joint evenly. In contrast to running sports, however, there is no sudden strain such as when stepping on the knee joint. Anyone who feels pain on the kneecap when cycling should therefore have this clarified.

Often they are due to excessive strain on the muscles and thus also on the tendons (patellar tendon and quadriceps tendon). Osteoarthritis behind the kneecap can also be the cause.

Pain when jogging

Jogging is a sport that has a continuous sequence of movements, but still demands a lot from the knee joint. With every step, pressure is built up on the knee joint, which is why even slight damage to the joint can lead to pain. Jogging should be paused, especially if the kneecap itself or the surrounding tendons and muscles are damaged.


The diagnosis of the disease that leads to the development of pain in the kneecap area is usually made over several steps.
Simple clinical examinations will in many cases supplemented by radiological proceduresThese are among the most important clinical investigations Palpation of the patella surface and assessment of the mobility of the patella. In addition, the ability to trigger pain in different positions of the knee joint must be recorded.

Inspection (appraisal)

The attending physician assesses during an initial First examine the leg axes from two planes (Frontal and sagittal plane). That way you can Misalignments such as bow or knock knees are excluded become. In addition, any deformations of the knee can be assessed. Also the Inspection of the muscles is essential in diagnosing kneecap pain. In order to get a first clue about the underlying disease, the Skin texture inspected in side-by-side comparison become. The doctor pays particular attention to this possible redness, swelling and scarring. In addition, must be on Swelling, dents and thickening in the area of ​​the kneecap and the hollow of the knee the affected patient should be respected.

Palpation (palpation)

In a further step that will be Thoroughly palpated the knees and kneecap. The attending physician pays particular attention to this Typical signs of inflammation are present. Overheating of the kneecap in comparison to the lower and upper thigh muscles speak for one Inflammation within the knee joint. At Effusions can cause a so-called when the joint space is streaked out with the knee joint extended "Dancing patella" can be observed.

MRI of the knee

Kneecap pain can have many different causes.
If the above-mentioned examination methods do not determine the cause, an MRI examination of the knee is recommended.
It can capture many different possible changes in the knee joint area and thus be diagnostically groundbreaking. For example, pain in the kneecap may be cartilage damage. The kneecap has a cartilaginous coating on the underside and slides in its cartilaginous plain bearing consisting of the upper and lower leg bones.
If there is an injury or an arthritic lesion, this can be detected in the MRI and the size and depth of the cartilage damage assessed.
The quadriceps tendon can also trigger the symptoms. It is the tendon of the greater thigh muscle, or the front of the thigh, that attaches to the kneecap and extends as a patellar tendon from the kneecap to the front of the tibia. Injuries to this tendon apparatus can also be recorded with high accuracy in the MRI (tears, partial tears, inflammations).
This already covers the most important causes of pain in the kneecap area. Irritation of tendons, ligaments and joint capsules can also be shown. The irritated structures are usually thickened and signal-reinforced / low-signal.
The so-called Hoffa fat body is located in the knee joint area. It is a collection of fatty tissue between the kneecap and the shin.
In Hoffa-Kastert syndrome, the Hoffa fat body is enlarged and leads to pain and restricted mobility in the knee joint. The syndrome is best diagnosed with an MRI of the knee.

Read more on this topic under: MRI of the knee

Other research methods

In addition to the examination methods just described, extensive functional examinations are often used for pain in the kneecap. In these examinations, the behavior of the patella in different positions and under different motion sequences is assessed.
In addition, radiological procedures (X-ray, MRT) can be used for diagnosis.