By | June 10, 2022

Knock knees are a result of a congenital deformity of the feet that can be corrected to some extent. Left untreated, knock knees can lead to symptoms.

What are knock knees?

The term knock-knees refers to a certain type of bending of the legs compared to a normal straight position. A distinction is made between two forms of bending, namely the vagus position, which means bow legs, and the valgus position, which is also known as knock knees. In the latter position, the thighs and lower legs are at an angle of more than 186° when viewed from the knee joint. For meaning of hypotrichosis in English, please visit sportingology.com.


The causes of knock knees are not considered to be congenital, but they are said to arise indirectly from a malposition of the feet, which is congenital. In children, knock knees are common and “grow together” again.

However, there are also forms of knock knees that are caused by a congenital weakness of the connective tissue. However, a deformation of the bones can – contrary to the above opinion – also be congenital.

Such malpositions are what is known as flat feet, in which, as the name suggests, the foot is in a position that is slightly bent laterally outwards. In addition, with such a misalignment, the foot is lowered, that is, it lies flat on the ground, since the natural padding of the foot is not effective in the misalignment.

The result is that the legs are in an awkward position relative to the knee. The “lever-like” effect of the lower leg on the knee impairs the growth of the leg, which can later lead to knee problems and hip problems.

One cause may be untreated rickets in childhood. In rickets, the bones don’t harden properly and deform because they can’t fully support the body’s weight. Rickets can be caused by a lack of fat-soluble vitamin D. For this reason, children used to be given the unpopular cod liver oil. However, rickets can also be triggered by a lack of phosphatase. This is then called hypophosphatasia.

The whole thing can lead to arthrosis of the knee joint, a so-called gonarthrosis. In addition, knock knees put more strain on the femur joint and thus also on the lateral meniscus. Lateral arthrosis can also occur.

Other possible causes of knock knees are fractures, hormonal changes during menopause and obesity.

Diagnosis & History

The diagnosis is based on the appearance and with the help of a so-called treadmill. X-ray technology is also used for osteoarthritis. The latter also applies to the slight shapes of the X-legs, which are difficult to see from the outside.

But a diagnosis can also be made based on various complaints that are common with knock knees. This is where the most likely complaints are in the knee joint. This process can develop insidiously and will produce complaints of the arthritic type.

In addition, hip joint problems can indicate an X-position of the legs. The orthopaedist can also use a malposition of the feet to determine whether there is a tendency to knock knees. If the diagnosis is made at a young age, the course can still be influenced best.


As a rule, knock knees have a very negative effect on the quality of life of those affected. The patients suffer from very severe restrictions in movement and thus severe limitations in their everyday life. Furthermore, it can lead to teasing or bullying, especially in children or young people.

As a result, many patients also suffer from depression or mental disorders. It is also not easy for the patient to carry out strenuous activities or sporting activities. As a result, child development is also significantly restricted. The knock-knees also severely damage the joints in the knees, which can lead to osteoarthritis.

Broken bones also occur more frequently, so that those affected have to protect themselves more against accidents and other dangers. As a rule, knock knees can be treated relatively well with the help of surgical interventions. The earlier the procedure takes place, the higher the chances of complete healing. There are no complications. However, the patients are often dependent on examinations and the wearing of insoles. The knock-knees do not negatively affect the life expectancy of the patient.

When should you go to the doctor?

Knock knees are a visual change in body shape in direct comparison to the norm. Nevertheless, for a large number of those affected, they do not represent any disease value. If there are no other complaints or impairments in locomotion, no doctor is needed. A doctor should be consulted if there are physical or mental irregularities or states of stress. In the event of emotional suffering due to the visual flaw, the person concerned needs therapeutic help and support. You should learn how to deal with the abnormalities so that no psychological consequences or illnesses develop. If irregularities in locomotion occur during the growth process of the child, a doctor should be consulted.

In the event of pain, unsteady gait or poor posture, the symptoms must be clarified and examined. To avoid long-term damage and to prevent uneven posture, a doctor’s visit is advisable. If physical activities can only be performed with great effort or if there are irregularities in the muscular system, the abnormalities should be discussed with a doctor. If the physical resilience decreases or if there are problems with the joints, medical help should also be sought. The sooner the changes in the skeletal system are discussed with a doctor, the faster regulatory measures can be taken. It is therefore advisable to clarify the development as early as possible, especially in the case of knock knees.

Treatment & Therapy

If knock knees appear during the growth phase, therapy is rarely necessary. However, if there is still an axis deviation of more than 20° at puberty, an operation may become necessary.

There are several possibilities for this:

  • A small piece of bone is surgically removed to correct the misalignment.
  • The growth plate is temporarily stiffened to stop the leg from growing any further.
  • The growth plate is permanently stiffened, and even then the leg cannot grow any further.

Knock knees caused by rickets can go away on their own if the misalignment is not too severe. In the latter case, the muscles will increase the angle to the outside.

Another treatment option is to have insoles made for the shoes to correct the foot position a little. In the case of X-legs, the inside under the respective foot will be reinforced. The knee joint is then loaded more in the outward direction.


For the prophylaxis of knock knees, basically only an operation against the misalignment would be possible. Furthermore, if growth is not yet complete, the growth plate can be destroyed. For this purpose, the bone age must then be determined.


Follow-up treatment is necessary if knock knees have been corrected as part of a surgical procedure such as a corrective osteotomy. After the operation, the patient has to stay in the hospital for about four to five days. If there are no complications, such as pronounced swelling, during this period, he can return home.

During the first two to three weeks after the conversion osteotomy, the treated leg must be rested consistently. This means that only loads of a maximum of 20 to 30 kilograms may take place. For support, the patient uses crutches for about four to six weeks. Because today angle-stable plate systems are used during the operation, the leg can be fully loaded after just three weeks, but this also depends on the individual healing process.

Targeted physiotherapy plays an important role in the follow-up treatment of knock knees. The patient performs special physiotherapy exercises that accelerate the healing process. Later, light sporting activities such as swimming or cycling are possible again.

In younger patients, the inserted metal plates can be surgically removed. However, many of those affected do not want any removal at all, since the plates do not cause them any problems. After three to four weeks, the patient can go back to office work. For heavy physical work, the waiting period is usually three months.

Symptoms, Ailments & Signs

Knock Knees are easy to spot from the outside. In this case, the legs are shaped like an X and are no longer in the optimal position in relation to the knees. The child then suffers from growth disorders in the legs. Small children often also suffer from flat feet.

In this case, in addition to the X-legs, the feet are slightly bent outwards so that they lie flat on the ground. As a result, their padding to the floor is no longer optimal. Leg deformities are often so slight that they grow out on their own. Deviations of up to five degrees are still considered normal.

Misalignments start at a deviation of five degrees. However, in severe cases, surgery is often necessary to correct the deformities. This is the case when the axis of the legs deviates by more than 20 degrees. In mild cases, the knock knees in children and adolescents can often be corrected with the help of physical training.

In addition, special shoe inserts often support the correction of the misalignment. In adulthood, knock knees are caused by a variety of reasons. Obesity is often the cause. But tumors and hormonal changes can also sometimes contribute to deformity of the legs. People with knock knees often suffer from knee problems because there is constant inflammation there. Arthrosis can develop in the severe forms.

You can do that yourself

In everyday life, general locomotion and gait can be consciously controlled and optimized. The movement sequences should be reflected on several times in daily events and changed in the event of irregularities. This is necessary to achieve long-term improvement.

Training units or exercises learned in physiotherapy can be carried out independently and independently at any time. Lifting and carrying heavy loads can put a special strain on the skeletal system. Therefore, these movement sequences should be aligned to the needs of the organism. Wearing optimal footwear is essential in order to alleviate existing irregularities and not to trigger a deterioration in the overall situation. Therefore, flat and closed shoes should be worn. These should not be too heavy and made of materials that are comfortable and breathable.

Clothing choices can help alleviate emotional discomfort. Pants with a wide leg cut and made of loose-fitting material help to hide the appearance of the legs. This can trigger an improvement in general well-being and thereby reduce cognitive stressors. In the long term, self-confidence needs to be supported and stabilized. As long as knock knees do not lead to any physical discomfort, it is helpful to reduce mental sensitivities. This leads to an overall improvement in the general quality of life.