The genu varum designates a deviation of the knees outward. It is said to be physiological before 3 years old, and pathological when it persists. In common parlance, we sometimes speak of “bow legs”. The two knees move away from each other. Certain treatments may be considered in the event of pathological genu varum.

Definition of genu varum

The genu varum refers to a deviation of the knees that settles during growth. At birth, the axis of the lower limbs is not yet fully established. The newborn naturally has a genu varum, that is, a deviation of the knees outward.

The axis of the lower limbs will gradually be reversed with the occurrence of a genu valgum (deviation of the knees inward) before finding the adult physiological alignment. However, there are cases where genu varum persists. It is said to be pathological, in opposition to the physiological genu varum which occurs during the first years of children. The pathological genu varum can have many explanations which are detailed below.

Knee causes du Var

Up to about 3 years old, genu varum is considered physiological. It constitutes a stage in the growth of the child. The knees will then gradually align with the adult physiological axis.

The genu valgum is considered pathological if it does not subside. This case is a sign of damage to the growth cartilage which may have a congenital or acquired origin. The main causes of pathological genu varum are:

• congenital varus which is usually the result of fetal malposition;
• vitamin D deficiency rickets or vitamin-resistant rickets, which results in defective or delayed bone mineralization;
• achondroplasia which is a genetic disease resulting in dwarfism;
• Blount’s disease, which is characterized by a growth defect in the tibia;
• certain dysplasias, that is, disorders in the development of tissues or organs such as focal fibrocartilaginous dysplasia.

DIAGNOSTIC knee du Var

It is based on a clinical examination. In particular, the healthcare professional will measure:

• the inter-condylar distance, that is to say the distance between the internal condyles of the femurs;
• the femoro-tibial angle, that is to say the angle between the femur (single bone of the thigh) and the tibia (bone of the leg).

In the majority of cases, the diagnosis of genu valgum is made in children. This should be placed in a standing position with the knees extended and the kneecaps facing forward. If the child refuses, the examination can be performed while lying down.

To deepen the diagnosis and identify the cause of genu varum, additional examinations may be performed. The healthcare professional may in particular request:

• medical imaging examinations;
• a dosage of vitamin D.

People affected by genu varum

Genu varum can be seen in many children between 0 and 2 years old. It then constitutes a stage of normal growth.

The pathological genum varum is rarer. It occurs when the deviation of the knees persists after 3 years. It is usually diagnosed in children but also sometimes in adults.

Several factors can increase the risk of pathological genu varum:

• genetic predisposition;
• early overweight or obesity;
• deficiencies, especially vitamin deficiencies;
• the practice of certain sports, most often at a high level.

Deflection of the knees to the outside

The genu varum is characterized by a deviation of the knees outward. The two knees are far from each other. In common parlance, we sometimes speak of “bow legs”. Depending on the case, the deviation of the knees can be:

• unilateral or bilateral;
• more or less severe;
• symmetrical or asymmetrical.

Other symptoms

• Discomfort when walking: When it persists, the genu varum can tend to disturb the movements of the lower limbs. Sometimes the discomfort can be accompanied by pain in the knees and stiffness.
• Risk of complications: The pathological genum varum can lead to a progressive destruction of the cartilage. This constitutes a risk factor for gonarthrosis (osteoarthritis of the knee).

Before 3 years, a physiological genu valgum does not require any treatment. This is a normal growth stage. The outward deflection of the knees naturally fades.

On the other hand, treatment can be considered in certain cases of pathological genu varum. It depends on the identified cause and the perceived symptoms:

• vitamin D supplementation in case of deficiency;
• an osteotomy which is a surgical operation aimed at repairing bone and joint deformities;
• deepiphysiodesis, which is a surgical procedure to reduce epiphysiodesis (growth disorder with trauma to the cartilage);
• orthopedic treatment with, for example, the wearing of splints and / or insoles;
• physiotherapy sessions;
• anti-inflammatory and analgesic treatment for severe pain in the knees.

Some cases of genu varum cannot be prevented, especially those of genetic origin. On the other hand, other cases are linked to preventable risk factors. In particular, it is necessary to:

• prevent and fight against overweight in children;
• maintain a balanced and varied diet to avoid nutritional deficiencies in children.