The shinbone (tibia) may be twisted at birth.
Birth defects, also called congenital anomalies, are physical abnormalities that occur before a baby is born. "Congenital" means "present at birth." (See also Introduction to Birth Defects of the Face, Bones, Joints, and Muscles.)
The shinbone (tibia) is one of the bones in the lower leg. Twisting (called torsion) of the tibia toward the outside (external torsion) occurs normally as the child grows and is rarely a problem. Twisting toward the inside (internal torsion) is common at birth and typically resolves as the child grows. However, a great degree of torsion may indicate a neuromuscular problem or Blount disease. Persistent, excessive internal torsion can lead to toe-ing in (pigeon toes) and bowlegs.
Doctors can detect this birth defect by doing a physical examination and taking various measurements of the legs.
In most children, the shinbone returns to a normal position without treatment around 5 to 6 years of age. Children who have a severe case of tibial torsion may need to wear special shoes, a cast, or leg braces.
