X- and O-leg

FrequencyBowlegs and knock-knees are very common in young children and are often a normal stage of development. Around 80 % of children under the age of 3 show a slight bow-legged posture, which balances itself out over time. From the age of 3, many children develop a knock-kneed posture, which usually normalises again by the age of 8. In older children or adolescents, however, a deformity can persist and rarely progress.

CauseThe cause of knock knees or bow legs often remains unclear. In some cases, imbalances in bone development or misalignments of the hip or foot can also influence the leg axis. More rarely, genetic diseases, malnutrition or damage to the growth plates are the cause.

The most common symptoms are a visible misalignment of the legs, which can lead to an uneven load on the joints. Children with bow legs often have a greater load on the inner knees, while those with significant knock knees have a greater load on the outer knees. In some cases, walking may be impaired and pain may occur, particularly in the case of advanced deformities or unfavourable guidance of the kneecap.

The treatment of knock knees and bow legs depends on the severity of the deformity, the presence of symptoms and the age of the child. In most cases, no special measures are required as the deformity corrects itself as the child grows. Conservative treatment such as physiotherapy or special exercises to strengthen the muscles and correct posture can help in some cases. In the case of more pronounced deformities or if the deformity persists into old age, surgical correction may be necessary.

Growth guidance is still an option during the growth phase. In this technique, small access routes are used to influence the growth zones of the upper or lower leg bones, usually close to the knee, in order to determine the direction of growth for these growth zones and thus achieve “straight growth” simply by influencing natural growth. This is very effective and comparatively low-risk if it is an option.

Once growth is complete, the bones can be repositioned by cutting them and adjusting them correctly, but this is a more extensive procedure than growth control, with a correspondingly different risk profile.

Without treatment the malalignment can disappear by itself in many cases during childhood and adolescence. In rare cases, especially with more severe deformities or acquired causes, permanent joint problems and pain can occur.

With treatment the prognosis is very good in most cases. Early intervention, especially with surgical measures, usually leads to a complete correction of the deformity and the avoidance of long-term complaints.