Medical Author: Melissa Conrad Stoppler, MD
Medical Editor: Dennis Lee, MD
It's quite common for toddlers to appear mildly bow legged. In fact, toddlers can often have bowed legs that may even interfere with walking. The majority of cases of bowed legs in toddlers result from so-called physiologic genu varum, the term used by doctors to refer to a variation in normal appearance that makes some toddlers appear bow-legged. Toddlers with this normal variation in appearance of the legs usually begin to improve around the age of 15 to 18 months. By age three the problem has generally resolved without any type of bracing or treatment.
However, certain medical conditions can be responsible for bowed legs that do not improve, or even worsen as a child ages. Blount's Disease is a medical condition that affects bone growth, resulting in abnormal growth of the upper portion of the tibia, or shin bone, leading to bowed legs. Both toddlers and adolescents can develop this condition. According to the American Academy of Orthopaedic Surgeons, in children under two years of age it is impossible to distinguish "normal" bowed legs from Blount's Disease. However, children with physiologic genu varum will improve with time while those with Blount's Disease will progressively worsen. By age three, x-ray studies of a child's legs will show the abnormalities of Blount's Disease.
Blount's Disease is a treatable condition. When discovered early in toddlers (called infantile Blount's Disease), leg braces can be used to correct the condition. If bowing of the legs persists or increases despite the use of a brace, surgery may be needed. Braces are not effective in adolescent Blount's Disease, and teens with the condition are usually treated with surgery.
Other, rarer conditions may also result in bowed legs in toddlers. Disorders of metabolism such as rickets (a deficiency of vitamin D that is rare in developed countries) can also lead to bowed legs. If you're concerned about bowed legs in your child, your doctor can perform tests if necessary to help determine the cause of the problem.
Reference: American Academy of Orthopaedic Surgeons Web site, accessed 1/7/06.