Salter-Harris II fracture of the proximal humerus in a preterm infant.

A premature twin infant presented with clinical signs of shoulder injury shortly after birth. He had been delivered by cesarean section due to malpresentation. Bony abnormality was not initially recognized on plain radiographs, but ultrasound revealed a Salter-Harris II fracture of the proximal humerus. Plain radiographs are limited in the premature newborn because of lack of calcification of the epiphysis. Ultrasound examination in these infants can be helpful in determining the true extent of skeletal injury. Immobilization and pain control are then indicated to optimize the outcome.