Knock knees in children


X-legs are caused by an axis misalignment in the knee joint.

Under the so-called knock knees, also medically as Genu valga refers to an axis misalignment of the legs.

In doing so, the knees tend to move into the middle compared to the actual leg axis.

Since this way the loads (especially your own body weight) are not distributed over the joints as anatomically intended, problems, incorrect loads and ultimately damage to cartilage and bones can occur.

Especially with small children, X legs can also appear temporarily as part of normal development. In such a case, the knock knees usually recede in the further course of development.


The main causes of X legs are in childhood congenital deformities. often by a whole series of small deviations arise in growth and embryonic development. Most common cause is one Misalignment of the feet.

Older children can also previous incorrect loads, lack of muscle strength or Misalignments of neighboring joints to be responsible.

In addition, knock knees can also occur after operations, accidents, inflammatory processes or some systemic diseases, such as Muscle or nerve disorders are caused.

Also rickets (Vitamin D deficiency) can lead to knock-knees, but then it is accompanied by other complaints.

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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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At the beginning of the diagnosis there is the anamnese with questions about occurred complaints, Pain or Malfunctions. Also previous accidents or similar illnesses in close relatives can indicate a misalignment. Increased wear and tear on the trousers on the inside of the knees is often noticeable.

In the physical exam especially the leg axes, the length of the legs, the stability of the knee and the Menisci as well as the mobility examined.

Also the Distance between both knees a straight stance can already give an indication. Then any disturbances or complaints of the Gait pattern judged. Generally should always also examined the adjacent joints become. Because X legs are indeed a misalignment of the knee, but the original problem can often also be in the hip joint or lie in the arches of the feet.

This examination can be supplemented by a X-ray of the knee, or a so-called Still shot of the whole leg and the adjacent joints.


X legs can for a long time without symptoms stay.

The misalignment can especially occur in childhood often well compensated become.

If there are complaints, they usually express themselves through Pain in the knee itself, or, if the cause is there, than Hip pain or Pain in the foot.

But even if the X legs remain symptom-free, it should always a medical evaluation occur because the joint wear and the possible long-term consequences of the incorrect loading greatly increased are.


target The therapy of the X legs in children is mainly the physiological leg axis as far as possible restore.

This will make the Reduced incorrect loads and the discomfort alleviated.

It is also the only way to prevent permanent joint damage, such as a arthrosis to prevent.

Conservative therapy

If acute symptoms occur, one should be asked during this period further burden (such as in sports) avoided become.

To reduce the pain that occurs and to contain any inflammation in the knee joint, drugs from the group of NSAIDs so e.g. Ibuprofen or Paracetamol be taken.

Also one Cold therapy and certain electro-medical procedures such as the Stimulation current therapy can help in acute cases.

The goal of conservative therapy is always one Treatment of accompanying causes. So are some sports, for example gentler on the joints than others, e.g. come swim or To go biking rather in question than tennis to play.

If in addition to the X legs, too Obesity is available, you should definitely try to reduce it.

The joints of overweight children are more heavily stressed anyway, if this also coincides with an axis misalignment, one can easily understand that the Joint damage increases massively. In order to absorb the strain on the joints, a physical therapy to strengthen the stabilizing muscle groups.

A therapy with insoles or night splinting is not considered to be promising for the child. The actually desired change in the direction of growth or "straightening" can usually not be achieved.

Operative therapy

In the case of a severe malposition, surgical therapy is advisable in order to prevent joint wear later on.

With stronger X legs, it can make sense to surgically treat the deformity even in the child. There are mainly two common surgical procedures.

In the Epiphysiodesis the growth plate, i.e. the part of the bone in which bone growth in children mainly takes place, is bridged or destroyed.

This can be done either as a temporary epiphysiodesis, in which growth is only inhibited for a certain time, or as a permanent variant. In this way, for example, an existing leg length difference can be compensated for. With X legs, it is possible to bypass the growth plate on one side of the leg, and so direct further growth in a straight line.

In the conversion osteotomy, the malalignment is corrected by correcting the bone near the joint, either on the thigh bone (Femur) or on the shin (Tibia), eliminated directly. This also means that the joint surfaces lie correctly on top of one another after the operation and further damage is prevented.

For more information on the operation described, read our main article: Corrective osteotomy

Both surgical procedures involve the general risks of any operation, such as Wound healing disorders, infections, or damage to nerves or blood vessels.

It is also rarely possible that a leg length difference occurs after the operation, which without appropriate therapy (Please also read our article on this Leg length difference) can of course cause bad posture.

Read more on the topic: Operation of knock knees


Targeted prophylaxis is not possible.

Also a correction of the incorrect load by insolesas in the adult is in the child to be seen more critically.

With X legs, however, attention should be paid to the fact that they are already elevated Reduce stress as much as possiblee.g. by reducing Obesity and joint-friendly sports (so.).

In infants, the Administration of vitamin D. in the first two years of life enforced in order to avoid malpositions caused by vitamin D deficiency (e.g. rickets)


There are no general numbers, like exactly an axis misalignment like the X legs with the development of one arthrosis or other complaints in the knee joint.

Of the course is strong from individual extent dependent. So it is quite possible that with a slight misalignment that has never caused problems, too without treatment to no discomfort or joint damage comes.