Children throughout the world experience physical abuse that may go unnoticed. Radiologists may be the first clinicians to identify signs of potential abuse.
The number of articles published in peer-reviewed journals about this subject has increased markedly over the past decade. A recent two-article series in Clinical Radiology provides a concise and informative review of the important factors and signs of inflicted skeletal injury.
Radiologists from Sheffield Children’s Hospital NHS Foundation in the United Kingdom note that identifying skeletal injury caused by physical abuse compared to accidental injury can be challenging. Lead author Professor Michael Paddock, MD, of the University of Sheffield’s Academic Unit of Radiology, and colleagues advise that radiological findings alone do not necessarily confirm that a suspicious injury has been caused by abuse, but should be considered in the context of clinical history and examination, results of biochemical investigation, and prior imaging. Radiologists must have direct, face-to-face conversations with the patient’s pediatrician and other medical professionals providing treatment and/or consultation.
The authors list common clinical features that should raise suspicion of an inflicted injury. These include history of household falls resulting in fracture, delay in seeking medical attention for the child, and an explanation of the cause of the injury that is incompatible with the injury itself. Multiple fractures with no family history or concurrent history of bone disease, a torn frenulum, and a retinal hemorrhage should raise concern.
It is also important to consider fractures in the context of a child’s mobility and normal developmental milestones. Fractures in pre-ambulant infants are highly suspicious for physical abuse. A classic metaphyseal lesion is caused by extreme force across the metaphysis resulting in cumulative microfractures of immature bone. Such an injury is very rare in the normal handling of an otherwise healthy infant. Lower-limb fractures in pre-ambulant infants in the absence of an appropriate history (for example, a high-energy impact from an automobile accident) are also highly suspicious. By comparison, a “toddler’s fracture” typified by an undisplaced spiral fracture of the tibia is a common accidental injury in early toddling children to the age of about 4 years. In this latter situation, it is also not uncommon for a caregiver to have not recalled an injury taking place or to give a history of an impact.
The gold standard for skeletal imaging of suspected child physical abuse is the skeletal survey. The advantages of a skeletal survey are the ability to detect occult bony injuries, to aid in the dating of fractures, and to identify medical conditions, such as skeletal dysplasia or metabolic disorders that may result in fractures. The articles include a detailed table of the projections required for a skeletal survey.
The authors recommend a full skeletal survey in children under the age of 2 years when abuse is suspected. Follow-up imaging, to comprise at least a chest radiograph approximately 11-14 days later, may enable identification of fractures not previously seen due to interval healing and can help date injuries.
Metaphyseal fractures and lower and upper limb fractures are the most common bony injuries associated with physical abuse. The distal femur, proximal and distal tibia, and proximal humeri are the most common locations for metaphyseal fractures. The authors state that long-limb fractures of infants are also highly suspicious for abuse in the absence of a high energy-impact injury such as a traffic accident. A diaphyseal spiral/oblique fracture of the femur is the most common abusive femoral fracture in pre-ambulant infants and those aged less than 15 months. A humeral fracture is also highly suggestive of abuse in a child under the age of 18 months in the absence of an appropriate history. However, supracondylar fractures are a common accidental injury in children between the age of five and seven years. These are frequently caused by a fall from playground equipment, an elevated porch, or the top bunk of a bed onto a hyperextended elbow.
Metacarpal and metatarsal fractures are very uncommon and may not be identified during clinical examination. The authors recommend that radiologists consider the sites of other unusual fracture locations suspicious for physical abuse by remembering the three S’s: Scapulae, Sternum, and Spinous process fractures.
Acute rib fractures are difficult to detect when they are incomplete and minimally displaced. When rib fractures are suspected, performing a chest CT scan may be appropriate in certain instances as a problem-solving tool. However, chest radiography, including anteroposterior and oblique projections, should be obtained in the first instance, at initial presentation and on follow-up imaging.
The authors point out that posterior rib fractures are highly specific for abuse, especially in children under 18 months. Anterior rib and costochondral fractures of the lower ribs are often associated with major intra-abdominal injury, which may result from direct blunt force to the chest wall. The authors state that patients with abusive rib fractures tend to have fewer concurrent intrathoracic injuries than those patients who have had an accidental injury. Rib fractures rarely occur as a result of cardiopulmonary resuscitation. (However, this remains a contentious issue in the published literature.)
Skull fractures may be associated with physical abuse. Because they may also be accidental in etiology, knowing as many details as possible of the clinical history of the patient is vital. Furthermore, multiple co-existing injuries may arouse suspicion. If additional brain and spine imaging are indicated independent interpretation by pediatric neuroradiology specialists may be needed.
The articles also review fracture dating, how to determine the mechanism of injury, and discuss differential diagnoses including normal variants. The authors caution that numerous normal variants may simulate physical abuse, such as osteogeneisis imperfecta, rickets, and sternal ossification centers.
Protocols must exist in radiology departments to manage studies that raise suspicion of child abuse. In addition to preparing a detailed radiology report, the authors recommend blinded independent double reporting of skeletal surveys.
“The diagnosis of child abuse is complex and imaging plays a large and important role. Radiologists need to take precautions so they do not make an erroneous diagnosis,” they wrote.
Detecting physical abuse in children: Imaging and reporting considerations for radiologists. Appl Radiol.