Blount disease

Alternative names:

tibia vara

Definition:

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 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 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.