A growth disorder of the tibia (the bone at the front of the lower leg, sometimes called the shinbone) that causes the lower leg to angle inward, resembling a bowleg.
Causes, incidence, and risk factors
Blount's disease occurs primarily in young children but can occur during adolescence . The cause is unknown. The inner part of the tibia just below the knee fails to develop normally, causing angulation of the tibia. Unlike bowlegs which tend to correct as the child develops, Blount's disease is progressive and the condition worsens. It can cause severe bowing of the legs and can affect one or both legs. The condition is more common among black children. It is also associated with obesity and early walking. There does not appear to be an obvious genetic factor.
Signs and tests
Physical examination shows that the lower legs angle inward. An X-ray of the knee and the lower leg confirms the diagnosis (see joints X-ray ).
Treatment
Milder deformity can be treated with a brace. Moderate to severe angulation is treated surgically and may require cutting the bone to straighten it with placement of steel pins.
Expectations (prognosis)
Return to normal function and cosmetic appearance is expected after treatment.
Complications
Progressive deformity can occur if the disorder is not treated.
Calling your health care provider
Call for an appointment with your health care provider if your child appears bow legged and the condition appears to be getting worse.
Prevention
Weight loss for overweight children may be helpful.