Rotational deformities of the tibia and foot in preterm infants.

Metatarsus adductus and medial tibial torsion are common in term infants. Our study shows that metatarsus adductus is rare, whereas medial tibial torsion does not occur in preterm infants with gestational ages of less than or equal to 30 weeks. These preterm infants have lateral rotation of the legs, external tibial rotation, and everted or normal feet at birth. This posture may explain the rarity of metatarsus adductus and medial tibial torsion in preterm infants.