Radiology of Postnatal Skeletal development: The proximal humerus

Abstract

Twenty-three pairs of proximal humeri obtained from human cadavers ranging in age from fullterm stillborn to fourteen years were studied morphologically and radiographically. Roentgenograms of the specimens demonstrated the osseous and cartilaginous portions of the epiphyses, using air/cartilage interfacing. Comparable clinical simulations were obtained by using water immersion of the specimens. The metaphyseal cortex remained thin and trabecular near the physis. Histologically this area had multiple fenestrations, which provide a potential pathway for childhood osteomyelitis into the subperiosteal space, and may also affect the biomechanics of this region (i.e., susceptibility to Salter epiphyseal fractures). As skeletal maturity was reached, thicker cortical (osteonal) bone extended toward the physis. The epiphyseal secondary ossification centers form an osseous connection shortly after the appearance of greater tuberosity ossification center, although this may not be radiologically evident until the child is older. The major intent of this roentgenographic survey is to provide a reference index of proximal humeral development for the adequate interpretation of shoulder radiography in children who have not yet attained skeletal maturity.