Relationship of the subperiosteal bone collar to metaphyseal lesions in abused infants.

We studied the relationship between the subperiosteal bone collar and forty metaphyseal lesions in specimens obtained at autopsy from ten infants who died with evidence of abuse. The fracture specimens were studied with high-detail radiography and light microscopy. The typical morphological pattern was a fracture extending through the primary spongiosa adjacent to the chondro-osseous junction. As the fracture line approached the cortex, it veered away from the growth plate, undercutting a fragment of bone that was thicker peripherally than it was centrally. Histological examination showed that this peripheral fragment of bone included the subperiosteal bone collar. Inclusion of the subperiosteal bone collar within the peripheral portion of the metaphyseal fracture fragment explains the radiographic appearance of corner fractures and bucket-handle patterns described by Caffey in abused infants.