Problem:

A child is brought to the emergency room by his parents, who maintain that he fell down a flight of stairs. They also describe easy bruisability. Frontal radiographs of the skull (figure

1), right shoulder (figure 2), and left wrist (figure 3) are shown, along with a posterior gamma camera view from a radionuclide bone scan (figure 4). What is the most likely diagnosis?

Discussion:

The proper workup of a child suspected of having been physically abused includes a radiographic survey of all of the long bones, the pelvis, the spine, the ribs, and the skull. Scintigraphy with bone-seeking pharmaceutical agents also may be a useful adjunct to the roentgenographic examination, although false-negative radionuclide studies have been noted and these examinations are more invasive and time-consuming than conventional radiography. Roentgenographic findings include single or multiple fractures, especially in the ribs though these also may involve, in order of descending frequency, the humerus, the femur, the tibia, the small bones of the hand and foot, and the skull. Diaphyseal or metaphyseal fractures can be seen in various stages of healing. Metaphyseal infractions may be quite subtle, requiring multiple projections for adequate visualization. "Unusual" fractures, such as those of the sternum, the lateral aspect of the clavicle, the scapula, and the vertebral bodies and posterior osseous elements, should arouse suspicion of abuse. Other clues to this diagnosis include overabundant callus formations, bilateral acute fractures, and fractures in the lower extremities in infants and young children who are not walking. Rib fractures that are bilateral and paravertebral and those that conform in distribution to the size of an adult's fist are suggestive of child abuse. Injury of the spinal cord may accompany vertebral trauma.

Subperiosteal bone formation may be apparent in a period of 7 to 14 days following the injury. This can vary in appearance from focal, thin periosteal deposits to massive bone formation. Periostitis with intramedullary foci of necrosis also may represent the sequela of traumatically-induced pancreatitis in the abused child. Late skeletal findings include metaphyseal cupping, growth disturbances, subluxation, and diaphyseal widening due to subperiosteal apposition.

Extraosseous alterations may include cutaneous lesions, myositis, malnutrition with decrease in subcutaneous fat, pulmonary contusion and laceration with pneumothorax, gastrointestinal hemorrhage with mass formation and obstruction, pancreatitis, hepatic and renal injuries, mucosal alterations in the mouth and palate, ocular lesions such as retinal detachment, and intracranial and subdural hematomas.

Disorders that must be differentiated from this syndrome are the normal periostitis of infancy, osteogenesis imperfecta, types of congenital insensitivity to pain, and infantile cortical hyperostosis. Metaphyseal avulsion fractures also may accompany abnormal copper metabolism in "kinky hair" syndrome (Menkes' syndrome). Metaphyseal changes in a variety of other congenital disorders, and of scurvy also may resemble those in the abused child syndrome.

Several other points of the differential diagnosis should be mentioned. The typical age range of children with nonaccidental trauma is from one to four years; after this age, children generally are able to escape the abusing parent or, at the very least, can verbalize what has occurred. Common accidental injuries in the young child are torus fractures of the distal portion of the radius, spiral fractures of the tibia (toddler's fractures), and clavicular and skull fractures. Accidental fractures of tubular bones require that the child be able to accelerate himself or herself; thus, an infant alone cannot break a humerus and a crawling child cannot break a femur. Rarely, passive exercise or physical therapy in premature children can result in injuries that simulate those of child abuse.

References

1. Resnick D, Niwayama G: Diagnosis of bone and joint disorders, ed 2. Philadelphia, WB Saunders, 1986.

This series of diagnostic challenges is prepared by David J. Sartoris, MD, Professor, Department of Radiology, University of California School of Medicine, San Diego, CA.