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.