I know parents are often terrified when they find out their child has a spiral fracture, because, so often, this is considered a definite sign of child abuse because of the way the bone has to break.
I knew a couple whose little girl got a spiral fracture in her leg after falling off the sofa. She was about 18 months old. Child services were called and the child was put in foster care for about two weeks while the "investigation" went on.
Finally, the child's pediatrician intervened on behalf of the parents and insisted the child be given a bone density scan. Turns out, she had brittle bone disease. Fortunately, the child was returned immediately to her parents.