CT Bone Density in a Case of Osteogenesis Imperfecta-type 1 (OI) Presenting with Suspected Child Abuse 666

Abstract

Infants with OI can be mistaken as victims of child abuse when they present with multiple unexplained fractures (MUF). Some believe that radiographic features can distinguish child abuse from OI (ie metaphyseal fractures and posterior rib fractures are diagnostic of child abuse), and that infants with OI will have other features such as a positive family history, Wormian bones, or radiographic evidence of osteopenia that would distinguish the two entities(J Ped 128:542-547,1996). We have evaluated an infant with OI whose findings challenge this position. A 4 month old female presented when the mother noted the infant began screaming after she tried to dress the infant in a shirt. The infant had 3 old, posterior rib fractures, a fracture of the right acromium process, a left clavicle fracture, and a metaphyseal fracture of the left humerus. Evaluation by a child abuse team concluded that this was child abuse and not OI, because there were no other features of OI and the types of fractures were diagnostic of child abuse. The infant was removed from the parents, although they denied wrongdoing. At 5 months of age, while in foster care, the infant presented with new, metaphyseal fractures of the right humerus and left femur. At 9 months of age a CT bone density study showed a very low cortical bone density (CBD) of -3.8 SD compared to 7 control infants. Other children with OI who have been studied have also shown a very low CBD. A skin biopsy was then performed for collagen analysis which was consistent with OI. We conclude that: 1) infants with OI can present with only fractures and have no other findings indicative of OI, 2) infants with OI can develop metaphyseal fractures and posterior rib fractures, and 3) CT bone density measurements can help in distinguishing child abuse from OI.