In the children’s orthopedics clinic, there are not a few parents who seek medical advice due to children’s lower limb deformities or asymmetry. With the impact of declining birthrates, every child is a baby held by the parent in the palm of his hand. Once the physical appearance or gait is found being different from other children of the same age, can inevitably cause the parents to worry about delaying the golden treatment period and regret it. Among them, the child’s knock knees and bow legs are one of the reasons why many parents visit the clinic.
In fact, the vast majority of cases in outpatient clinics are normal physiological developments, or just individual differences within a normal range. Therefore, allowing parents to have a basic knowledge of children’s bone growth and development in advance, can alleviate family anxiety and improve the dilemma of flocking to the hospital for treatment.
What exactly are bow legs and knock knees?
A normal foot is not completely straight, but a little valgus, which is within 6 degrees on average. When a child stands upright, under normal circumstances, when viewed from the front, the knee joints and the inner ankle joints on both sides will be close to each other, and the legs will be in a straight line. However, if the ankles are close but the distance between the knees is too large, it will appear bow legs from a distance, called knee varus, or commonly known as bow legs; conversely, it can also be that the knees are close but the distance between the ankles is too large. It presents an X shape, which is called knee valgus or commonly known as knock knees.
If a child develops unevenly on both sides of the leg bones during development, resulting in knock knees or bow legs, it will cause unbalanced forces on both sides of the knee joint for a long time, which will lead to loose and unstable lateral ligaments, and meniscus damage. Wait. In addition to feeling pain and abnormal posture when walking or exercising, in the future, it will also be one of the main reasons for the inconvenience of walking due to early degradation and wear of articular cartilage in adults.
Pendulum phenomenon of children’s bone growth
Children’s skeletal development will go through a process called the “pendulum phenomenon”, that is, the angle of the legs of children from 0 to 8 years old will change from bow legs to straight, then to knock knees, and then straight. Normal physiological phenomenon.
Because of the compression of the baby in the mother’s body before the baby is born, the normal newborn’s calf shows an inward angle of about 10 to 15 degrees. When a newborn starts to learn to stand or walk, weight bearing will make the bow legs stronger, especially when they are 6-12 months old. Between 18 months and 2 years old, the feet will gradually straighten. But after that, the bow legs leg will continue to be corrected, and then overcorrected, and become an knock knees, which is most obvious at 4 years old. After that, the knock knees slowly return to normal, and they will gradually become normal before the age of 6-8.
For any reason, children’s legs cannot develop normally according to the pendulum phenomenon, it is recommended to consult a doctor to understand the reason, such as 2 to 5 years old, the legs are still bow legs; 6 to 8 years old, the legs do not straighten, whether it is bow legs or knock knees requires inspection; or regardless of age, if the two legs are asymmetrical, it is recommended to have a professional pediatric orthopedist check it.
Sick bow legs or knock knees should be actively treated
Pathological deformation of the knee joint cannot be healed automatically by growth, and treatment must be actively sought to avoid more serious sequelae. Common causes of pathological knee joint deformation include abnormal growth plates, bone and joint metabolic diseases, a history of bone injury or infection, or local benign bone tumors. These conditions are easily screened by X-rays or other tests.
What is the surgical treatment?
In a growing child, if the basic function of the growth plate is not lost due to excessive knee joint deformation, the more common surgical treatment is “Growth Plate Growth Direction Control Surgery”, which is a low-invasive minimally invasive surgery The method is to make a small wound skin incision near the unilateral growth plate, implant a growth plate inhibitor, and then suture the wound.
This kind of surgery is a bit like the concept of braces. After installation, the growth plate will be forced to change the direction of growth, and slowly straighten the bent leg. It takes several months to a year. After the correction is completed, the built-in The metal can be removed and normal growth can be restored. Generally speaking, before the arrival of menstruation for boys and girls, it is the golden period of surgical treatment.
