Bowlegs (Genu Varum)
At birth, all babies are somewhat bow-legged because, within the cramped space in the uterus, the legs are likely to fold over each other. This condition is referred to as genu varum in medical parlance. (In Latin, genu means knees and varum means inwardly curved.) In the simplest terms, legs are defined as bowed if, when the ankles touch each other, the unbent knees do not.
In practically all cases, mildly bowed legs correct themselves, even if the condition persists until the child is three years old. When only one leg is bowed, however, the cause may be a turning in of the leg bone resulting from a birth injury or an inherited degenerative disease of the knee.
Diagnostic Studies and Procedures
A pediatrician normally checks a baby's legs during routine examinations. If the bowing is less than 20 degrees, chances are that the problem will correct itself. However, a bowing of more 20 degrees after the age of 18 months, or one that is progressing or causing pain when walking, should be investigated by a pediatric orthopedist. Mildly bowed legs that fail to straighten out spontaneously by the time the child is four years old also warrant an evaluation by an orthopedist.
In arriving at a diagnosis, the doctor will ask about family medical history, nutrition, and any birth injuries. An X-ray may show bone deformities or injuries. If there is a family history of bowlegs and knock-knees, a genetic disorder is likely. Other possibilities include Blount's disease, or tibial osteochondrosis, in which the shin bone curves inward because the growth plate ceases to function normally. This abnormality may develop in children who walk early, or who are very short or obese. It may appear also during the adolescent growth spurt.
Bowlegs may indicate rickets, a disease caused by vitamin D deficiency due either to an inadequate amount in the diet, a lack of exposure to sunlight, or a genetic inability to absorb the vitamin. Without sufficient vitamin D, the body cannot utilize calcium, and the result is soft and deformed bones. Nutritional rickets is very rare in the United States, thanks to fortified milk and other basic foods that are enriched with vitamin D. Laboratory tests can detect the genetic form.
If the bowing is severe or worsening, braces and surgery are the first options to be considered. Correction should be undertaken as early as possible, first with braces, and if this treatment shows no positive results, with surgery to correct the faulty knee structure.
Blount's disease usually requires surgery to rotate the shin bone to its proper position. Otherwise the condition may eventually result in disabling problems of the knee joints.
Nutritional rickets is treated with large doses of vitamin D. The treatment of rickets that is caused by a genetic metabolic defect will vary depending on the nature of the disorder.
Responsible practitioners of acupuncture, chiropractic, and most other alternative therapies would not undertake the basic treatment of bowlegs. Some alternative therapies, however, may improve the underlying causes.
Light Therapy. Exposure to sunlight or an ultraviolet lamp stimulates the skin's production of vitamin D. Be careful when exposing a baby to the sun, however, because of the danger of sunburn. A few minutes in the early morning or late afternoon two or three times a week is all that is usually needed.
Massage Therapies. Massage, using gentle manipulative exercises by a practitioner trained in pediatric care, may be helpful. Physical therapists on the staffs of orthopedic clinics are also knowledgeable about these techniques, and can show you how to exercise the child's legs yourself.
Nutrition Therapy. If a physician has determined that a dietary deficiency or a metabolic abnormality is the cause of bowlegs, she may suggest that a nutrition therapist be consulted to prescribe the appropriate amounts of such supplements as calcium and vitamin D. Careful monitoring is necessary when giving a young child supplements of these nutrients because they are stored in the body and excessive amounts can result in severe liver damage, metabolic abnormalities, and kidney disorders.
When a baby appears to be bowlegged, parents should not encourage early walking, which can exacerbate the problem They should also avoid bulky diapers, which can push the development of bowlegs, especially when a baby starts standing and attempting to walk. If your baby is overweight, consult a pediatrician about a change in diet.
Other Causes of Bowlegs
In rare cases, an inherited metabolic disorder called neurofibromatosis may produce leg bowing and other neuromuscular abnormalities. Sometimes bowing occurs as a result of a fracture in the growth plate, or metaphyses, the part of a long bone that abuts the cartilage and covers the end of the bone. This condition usually corrects itself as the bone heals.