Eighty percent of abusive fractures occur in children less than 18 months of age, in contrast to 85% of accidental fractures which occur in children older than 5 years. Abusive fractures are consistent with a severe assault on the child. However, fractures are common accidental injuries, with up to 64% of boys and 40% of girls sustaining a fracture by their fifteenth birthday. Diagnosing abusive fractures requires a careful history of the alleged accident, taking into account the weight of the child, the height fallen from and the surface on which they landed, as well as ensuring that the history offered is consistent with the child’s develop Eighty percent of abusive fractures occur in children less than 18 months of age, in contrast to 85% of accidental fractures which occur in children older than 5 years. Abusive fractures are consistent with a severe assault on the child. However, fractures are common accidental injuries, with up to 64% of boys and 40% of girls sustaining a fracture by their fifteenth birthday. Diagnosing abusive fractures requires a careful history of the alleged accident, taking into account the weight of the child, the height fallen from and the surface on which they landed, as well as ensuring that the history offered is consistent with the child’s developmental ability, e.g. could they have climbed onto the surface described? It is important to establish whether there could be an underlying bony abnormality such as osteoporosis associated with prematurity, chronic disease or drugs, congenital bone fragility such as osteogenesis imperfecta, infection or mineral deficiency or whether the fracture in question could have been the result of a birth injury. Having excluded such causes, the following fracture patterns warrant investigation for possible abuse
* rib fractures, particularly in children less than 3 years old;

* multiple fractures, particularly if they show different stages of healing;
* long bone fractures in children who are not independently mobile;
* metaphyseal fractures of the femur in particular;
* spinal fractures without an adequate explanation;
* pelvic fractures where there is no history of massive trauma.
Rib fractures, in the absence of underlying bony abnormalities, birth injury or major trauma, have the highest specificity for abuse of any physical injury. Abusive rib fractures are frequently multiple, predominantly anterior or posterior, in contrast to accidental fractures, which are commonly lateral. Some children who present collapsed, may have undergone cardiopulmonary resuscitation (CPR), raising the question as to whether this has caused the rib fractures. CPR is an extremely rare cause of rib fractures in children, but when they do occur, they are anterior and may be multiple.
Long bone fractures are recorded in abuse; the commonest site is in the shaft of the bone, especially in the premobile child. Certain fracture types usually reflect accidental injuries, specifically supra-condylar humeral fractures, which are seen after falls in the increasingly mobile toddler. Metaphyseal fractures although difficult to see radiologically are reported more commonly in abuse than non-abuse and postmortem studies suggest that they are underdiagnosed on radiology.
Skull fractures also occur in abuse, but are difficult to distinguish from accidental fractures. They are the commonest fractures in any child less than 1 year of age. There is some evidence that complex or multiple/bilateral fractures or those that cross suture lines are commoner in abuse. However, the commonest abusive and accidental fracture overall is a linear parietal fracture. It is important to remember that any bone in the body may be fractured as a consequence of physical abuse.
As many abusive fractures may be occult, particularly rib fractures, which have a very high specificity for abuse, it is essential to look carefully. It is recommended that all children less than 2 years with suspected physical abuse undergo a full skeletal survey (SS), including oblique views of the ribs. If there is any remaining doubt as to whether fractures may be present or not, and the skeletal survey is negative, either a radionuclide bone scan may be performed or the child could be recalled for a repeat SS in 11–14 d, as each option will enhance the sensitivity of the original investigation in detecting abusive fractures. In addition, repeat SS may help in clarifying ambiguous findings or dating the fractures present, although this can only be done in broad time frames in terms of weeks rather than days.

Source: Forfar and Arneil’s Textbook of Pediatrics, 7E