The metaphyseal lesion in abused infants: a radiologic-histopathologic study.

The metaphyseal lesions in abused infants have highly distinctive radiologic characteristics. The so-called "bucket-handle" and "corner" fractures often form the basis for the diagnosis of abuse. However, despite the great familiarity with the radiologic appearances, no systematic histopathologic study of the metaphyseal lesions in abused infants has been carried out. An in-depth study of pre- and postmortem radiologic features combined with histologic analyses of the metaphyses from a group of four abused infants provides new insights into the nature of these peculiar lesions. The basic histologic alteration is a subepiphyseal planar series of microfractures through the most immature portion of metaphyseal bone. This fracture results in the isolation of a mineralized disc or portion of a disc that is identifiable radiographically. Depending upon the size of the injury, the degree of involvement of the periphery of the bone, and the radiographic projection, a bucket-handle lesion, corner fracture, or metaphyseal lucency will result. In some cases, the radiographs may be normal even though there is significant histologic alteration. Although cartilaginous injuries may play a role in infant abuse, none of the specimens examined in this study evidenced injury through the germinal layers of cartilage. On the basis of the findings described here, it is recommended that postmortem analysis of all radiographically suspicious metaphyses be carried out in cases of suspected infant homicide. If there are other clinical or pathologic indications to support abuse, a strong argument can be made for removal of radiologically normal but high-risk metaphyses. Instituting these procedures will require closer cooperation between the radiologist and the medical examiner, but the potential for reducing the number of infant homicides demands this enlightened approach.