Surgery is the only way to change the knee angle — for braces, shoe inserts and physical therapy are ineffective. Since normal leg development goes from bowlegs to knock-knees, surgery should be postponed until the child is at least 10 years old.

Two bones meet at the knee joint: the femur (thighbone) and the tibia (shinbone). Surgical treatment depends upon the maturity of the child. In younger children, whose growth plates are open and still growing, knee alignment can be changed by tethering the growth plates of the femur or tibia using staples. As the growth plate grows on the untethered side, the knee will grow out of its excessive angle.

In older children, who no longer have open growth plates, treatment consists of cutting, straightening and then holding the bones of the knee in place while they heal with metal implants, including pins, plates and screws.

Although both treatments have high success rates, they should be done only if clearly necessary and at the appropriate age.