Bowlegs or genu varum is present in all newborns to some degree. This is due to normal in utero position of the fetus and is most notable when your child begins to walk. This bowed appearance will gradually disappear by around the age of 2 years. There are several rare entities that may present with bowing, such as Blount disease or rickets, but the “normal” bowing can be distinguished by the following features:

1. present in both legs

2. it is not severe

3. growth is following the child’s curve

4. improvement by around age 2 years (by age 8-9 years for knock-knees)

Rickets is a disease related to a defect in bone metabolism. Bones are constantly undergoing change in that they are in a cycle of being built-up and broken down in a constant fashion. This process occurs through complex interactions between hormones, vitamins (vitamin D) and the major minerals that make up bone; calcium, phosphorus and magnesium. When there is disruption of any part of the balance of these interactions whether it be a deficiency of vitamin D in the diet, or low phosphate levels in the blood, kidney disease secondarily affecting phosphate metabolism, or medications affecting this balance, the result may be rickets. We rarely see vitamin D deficiency today because of the fortification of milk, although breast feeding mothers should be aware that the vitamin D in breast milk is not readily available to their infants and if exclusively breast feeding, their baby should take supplements or get 30 minutes of sun exposure per week. The other forms of rickets are also rare but if the above 4 criteria are not met, then your physician may opt to initiate a work-up for the more rare causes of bowing.