Genu varum and genu valgum in children and adolescents

With bow legs the knees stay apart while the feet are together; with knock knees the knees touch while a gap remains between the feet. In many children these leg positions are part of normal development. Babies and toddlers often have bow legs at first, and a knock-kneed phase may follow. As growth continues, the leg axis usually straightens out on its own. Only rarely is there an illness behind it, or any need for treatment.

These changes are very common in children: bow legs appear above all in the first years of life, knock knees often at nursery age. By school age the leg axis has usually come close to the adult form. A medical examination makes sense if the change affects only one leg, increases markedly, causes pain or difficulty walking, or persists beyond the expected age.

The position of the legs changes while the thigh bone and the shin bone grow. Newborns usually have bow legs. By around the second birthday the legs become straighter; at three to four years a knock-kneed position is often at its most pronounced. After that it usually decreases again. From about the age of eight the leg axis largely corresponds to that of an adult.

• The shape of the legs changes quite naturally with growth.
• Bow legs are usually normal in babies and young toddlers.
• As a child learns to walk, the legs become increasingly straight.
• At nursery age a knock-kneed position often develops for a time.
• By school age the leg axis usually sorts itself out.
• Family tendency and build influence the visible shape of the legs.
• Rarely, illness or injury disturbs normal bone growth.

Treatment depends on age, cause and extent of the leg position, on the symptoms, and on how much growth remains. It also matters whether the deviation is one- or two-sided and whether it is increasing. Most age-appropriate bow legs and knock knees need no treatment at all. We advise you, examine the leg position and follow the further development with regular check-ups.

An operation comes into question when the deformity is pronounced, continues to increase, or is unlikely to even out on its own. As long as enough growth remains, that growth can be used for the correction through a procedure at the growth plate. If growth is almost or fully complete, a corrective bone operation may be necessary. Which method is suitable is decided individually after a careful examination.