RCH Clinical Practice Guideline Paediatric Fractures

VFPMS Guideline: Forensic investigation of fractures

A fracture is a complete or incomplete break in the continuity of a bone. Fractures are the second most common injury caused by physical abuse (after bruises).  Many of these inflicted fractures are not clinically suspected primarily because they most often occur in pre-verbal and non-ambulatory infants. Occult (hidden) fractures should be actively investigated as discussed here (with a link to lower down on the page on investigation of occult fractures).

Key points:

• All fractures in non-ambulatory children are concerning for abuse.
  
• In infants, fractures are more commonly attributed to abuse than to accidents.
  
• No specific fracture type is pathognomonic for abuse.
  
• Certain locations and types of fractures generate significant concern for an abusive cause (specifically posteromedial rib fractures and metaphyseal corner fractures).
  
• Certain skull fractures are concerning for abuse (see VFPMS Guideline: Head injury).
  
• Multiple fractures and/or fractures of different ages generate suspicion regarding abuse.
  
• Dating of fractures is inexact.
  
• Many children with fractures will have minimal or no external sign of injury.

Investigations for known fracture:

Laboratory investigations for underlying medical causes of fractures

Investigations for associated (possibly occult) injuries

• In young children (especially <2years-old) with a known suspicious fracture, investigations should be performed to search for additional but occult fractures.

• In the presence of significant fractures suggesting the application of significant force, particularly to the torso, consideration should be given to screening for abdominal injury.

• In selected cases (including any young infant with a fracture) consideration should be given to screening tests for possible head injury (Abusive Head Trauma) including cranio-spinal trauma through shaking and/or impact.
  

Investigations for occult fractures:

1. When bruising prompts investigations for occult fractures

N.B. VFPMS currently recommends using skeletal survey and bone scan when radiological investigation of occult fractures is warranted (see discussion below for additional information in relation to this recommendation). Alternative methods of investigation (for example two skeletal surveys performed 10-14 days apart) may be more appropriate in some situations. This can be discussed with VFPMS staff at any time. 

The VFPMS supports the Wood et al recommendations regarding criteria for radiological investigations for occult fracture, as presented in the following table.

_{Wood JN et al. (2015) Development of Hospital-Based Guidelines for Skeletal Survey in Young Children With Bruises. Pediatrics. 135(2);e312-20.} 

2. When known fracture prompts investigations for additional occult fractures

N.B. VFPMS recommends using skeletal survey and bone scan when radiological investigation of occult fractures is warranted (see discussion below for additional information in relation to this recommendation). Alternative methods of investigation may be more appropriate in some situations. This can be discussed with VFPMS staff at any time.

The VFPMS supports the Wood et al recommendations regarding criteria for radiological investigations for occult fracture, as presented in the following table.

_{Wood JN et al. (2014) Development Hospital-Based Guidelines for Skeletal Survey in Young Children With Fractures. Pediatrics. 134(1);45-53.}

Discussion

As a general guiding principle, order investigations when a positive result might result in intervention that increases a child’s safety or might result in additional action. There are occasions when it is wise to confidently determine the nature and full extent of a child’s injury and other occasions when an element of doubt about the interpretation of subtle radiological abnormality might reasonably persist. Consultation with VFPMS senior medical staff is encouraged in these situations.

Imaging modalities

The optimal method for radiological investigation of occult fractures has not yet been determined and clinical practices vary across regions nationally and internationally. 

The current recommendation to perform a skeletal survey in conjunction with a nuclear medicine bone scan has been developed to maximise the fracture detection rate, minimise the time taken to detect fractures and minimize a child’s exposure to radiation (ALARA principle) balanced with the need to adequately investigate and mitigate child maltreatment.

A Skeletal Survey is the cornerstone of radiographic investigation of occult fractures. It must be complete (different protocols exist but a complete skeletal survey generally includes approximately 21 radiographs which includes oblique views of the ribs). Whenever a skeletal survey is performed it must be technically adequate. A babygram is not appropriate. “Double reporting” (reporting by two radiologists) of skeletal surveys is encouraged.

Pelvic, hand, foot and sternal fractures can sometimes be missed on skeletal survey and additional views may be required. Coned views might be used to further investigate an abnormality detected on routine radiographs.

When a high-quality bone scan cannot be performed and interpreted by nuclear medicine physicians who are experts in interpreting children’s bone scans, two skeletal surveys performed 10-14 days apart may be performed as an alternative method of investigation. If no bone scan is obtained, follow up skeletal survey is strongly recommended when there are equivocal findings on the initial skeletal survey or when the initial skeletal survey is normal but abuse is suspected clinically. The follow up skeletal survey might reasonably exclude radiographs of the skull, spine and pelvis (in order to significantly reduce the amount of radiation exposure and only slightly reduce the likelihood of detection of occult fracture). In this situation safety planning during the time interval between the first and second skeletal surveys may be required.

Either skeletal survey or Bone Scan performed alone will miss occult fractures. Radiographs may fail to detect rib fractures, particularly recent rib fractures, even when oblique views of the ribs have been obtained. Bone scans may fail to detect skull fractures and corner metaphyseal lesions in infants.

The use of CT scan modalities is being explored with interest in the field of forensic paediatrics. CT chest and abdomen in combination with skeletal survey of the limbs (but not the axial skeleton – ie., skull, spine, clavicles, ribs, scapulae and pelvis) might be worth considering under some circumstances however it must be recognised that there is currently no evidence of the utility of this method of investigation.

Ultrasound and MRI modalities might also be considered in some cases.

Age of child

As discussed in the tables above, radiological investigations for occult fractures are more often recommended in children under the age of 2years-old. However, when there is a strong suspicion of occult fracture in older children (generally up to 5years of age) or non-verbal children then serious consideration should be given to performing a skeletal survey.

Useful resources and articles:

• The Royal College of Paediatrics and Child Health’s review (UK, 2017) Child Protection Evidence - Fractures evaluates the literature on fractures and presents data on the following questions: Which fractures are indicative of abuse? What is the evidence for radiological dating of fractures in children? What radiological investigations should be performed to identify fractures in suspected child abuse? Does cardiopulmonary resuscitation cause rib fractures in children?
  
• The Canadian Paediatric Society’s Practice Point (Canada, 2018) The medical assessment of fractures in suspected child maltreatment: Infants and young children with skeletal injury provides a good summary of key points in suspicious fractures.
  
• The American Academy of Pediatrics’ Clinical Report (USA, 2014) Evaluating Children With Fractures for Child Physical Abuse provides a review of the differential diagnosis of suspicious fractures
  
• Wood et al.’s article (2014) Development of Hospital-Based Guidelines for Skeletal Survey in Young Children With Fractures presents the Children’s Hospital of Philadelphia’s approach to investigation for occult bony injury in patients with suspicious fractures
  
• Wood et al.’s article (2015) Development of Hospital-Based Guidelines for Skeletal Survey in Young Children With Bruises presents the Children’s Hospital of Philadelphia’s approach to investigation for occult bony injury in patients with suspicious bruising
  
• Kemp et al.’s article (2008) Patterns of skeletal fractures in child abuse: systematic review provides a review of fractures from abusive vs non-abusive mechanisms