Child abuse or osteogenesis imperfecta: how can we tell?

Osteogenesis imperfecta may be difficult to differentiate from nonaccidental trauma. Social history may prejudice the physician in favor of or against considering the diagnosis of child abuse. Three cases of osteogenesis imperfecta that were initially diagnosed as nonaccidental trauma are presented. The availability of biochemical analysis of type I collagen was instrumental in confirming the diagnosis of osteogenesis imperfecta in all three cases.