Non-accidental injuries

Non-accidental injuries (NAI) represent both ethical and legal challenges to treating physicians.

Radiologists are often the first to suspect NAI when confronted with particular injury patterns, and a knowledge of these is essential if the opportunity to save a child from future neglect is not to be missed. At the same time, it is essential that suspicion is not raised inappropriately as the consequences for an innocent but accused parent or guardian are significant.

In 2001 an estimated 903,000 children were victims of maltreatment including:

  • neglect: 57%
  • physical abuse: 19%
    • cutaneous injury: most common
    • fractures are noted in ~30% (range 11-55%)
  • sexual abuse: 10%
  • psychological maltreatment: 7%
  • medical neglect: 2%

A number of features have been recognised as suspicious:

  • injury in the non-ambulatory / totally dependent child
  • injury and history given are incompatible
  • delay in seeking medical attention
  • multiple fractures with no family history of osteogenesis imperfecta
  • retinal haemorrhage
  • torn frenulum
  • history of household falls resulting in fracture
    • despite falls being common, fractures are uncommon

A skeletal survey is performed in cases of suspected abuse to assess and document the extent of previous skeletal injuries. The so-called babygram (whereby the entire baby is imaged in one view) is not an acceptable substitute due to the overall lower quality that it produces; each anatomical region requires differing radiographic exposures and therefore should be considered. 

Bone scans are also able to detect radiographically occult fractures and should be considered when clinical suspicion is high.

A typical skeletal survey comprises plain films of the following:

Lead markers should be used in skeletal surveys, and some institutions will repeat radiographs that do not have a lead marker within the primary field. 

A number of fractures have been recognised as highly specific to non-accidental injury (rather than accidental injury). They include:

The ability to date injuries is critical for medicolegal purposes, and thus must be done carefully (please refer to specialist text for specific guidelines).

Traumatic periosteal injury can be seen up to 7 days post-injury (and therefore can be used for dating). Traumatic periosteal injuries can be seen on diaphyseal and rib injuries. Diaphyseal injuries start healing after one week. Healing should be complete by 12 weeks. Rib fractures are often missed, hence current practice is to repeat chest films in two weeks to observe for any healing fractures.

Metaphyseal (and costochondral junction) injuries do not heal with periosteal reaction and if visible are less than four weeks old. Skull fractures also do not heal with periosteal reaction and if seen are less than two weeks old.

  • skeletal dysplasias: one of the major, albeit uncommon, pitfalls in diagnosing NAI (e.g. Schmid-type metaphyseal chondrodysplasia, osteogenesis imperfecta I and IV), which may lack the florid features of the full-blown disease and can be easily confused with NAI
    • features to differentiate osteogenesis imperfecta from NAI include
  • growth plates can also cause a degree of confusion, most notably at the hip, base of the fifth metatarsal, elbow, and the acromion
  • birth injuries
  • rickets

Subdural haemorrhage in a child should be viewed with suspicion. Most often, the subdural haemorrhages will demonstrate varying ages.

A potential pitfall is interpreting subdural hygroma in a patient with benign enlargement of the subarachnoid spaces (BESS) as suggestive of NAI without other stigmata 9.

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Article information

rID: 10133
Section: Signs, Gamuts
Synonyms or Alternate Spellings:
  • Non-accidental injury
  • Battered child syndrome
  • NAI
  • Non-accidental injuries (NAI)
  • Non accidental paediatric skeletal injuries
  • Child abuse
  • Non-accidental injury (NAI)
  • Non-accidental paediatric injuries
  • Non accidental trauma
  • Shaken baby syndrome (SBS)
  • Shaken infant syndrome
  • Stress-related infant abuse

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Cases and figures

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    Case 3: bilateral subdural haemorrhages
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    Case 5: metaphyseal corner fracture
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    Case 6: skull fracture with suspected NAI
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    Case 7: with very subtle metaphyseal corner fracture
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    Case 9: different age SDH
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