Overview
Definition:
Nonaccidental trauma (NAT), also known as abusive head trauma or battered child syndrome, refers to physical injuries inflicted by a caregiver or another adult on a child
Metaphyseal lesions, particularly fractures of the metaphyseal-epiphyseal region, are highly suggestive of NAT due to their susceptibility to shearing forces
A skeletal survey is a comprehensive radiographic examination designed to detect occult fractures and evaluate the extent of skeletal trauma.
Epidemiology:
The incidence of NAT varies by reporting systems and geographic location
In India, data on child abuse is often underreported
However, it remains a significant cause of morbidity and mortality in infants and young children
Metaphyseal fractures are most common in infants under 2 years old, peaking between 6-18 months of age.
Clinical Significance:
Accurate and timely diagnosis of NAT is critical for child protection, preventing further harm, and ensuring appropriate medical and legal interventions
Metaphyseal lesions are considered pathognomonic for NAT in the absence of a plausible accidental explanation
A thorough skeletal survey is essential for comprehensive evaluation and medicolegal purposes.
Clinical Presentation
History:
Vague or inconsistent history provided by caregivers
Delay in seeking medical attention
History of recurrent injuries
Caregiver anger, defensiveness, or blaming others
Unexplained failure to thrive
Vomiting, lethargy, irritability, or seizures.
Physical Examination:
Bruises in various stages of healing
Lacerations
Burns
Fractures (especially metaphyseal, rib, skull)
Subdural hematomas
Retinal hemorrhages
Signs of neglect
Cord-like injuries.
Diagnostic Criteria:
No definitive diagnostic criteria exist
diagnosis is based on a high index of suspicion, exclusion of accidental causes, and correlation of history, physical examination, and imaging findings
Metaphyseal corner fractures (bucket handle fractures) are highly suggestive of NAT
Multiple fractures in different stages of healing are also concerning.
Diagnostic Approach
History Taking:
Detailed and specific questioning of all caregivers about the mechanism of injury
Explore developmental milestones and their relation to reported incidents
Inquire about previous injuries, hospital visits, and parental stress
Assess for domestic violence or substance abuse in the household
Document inconsistencies carefully.
Physical Examination:
A head-to-toe examination is mandatory
Pay close attention to skin for bruises, abrasions, lacerations, and burns, noting their location, color, and pattern
Palpate the entire skeleton for tenderness and deformity
Perform a thorough funduscopic examination for retinal hemorrhages
Assess for neurological deficits.
Investigations:
Skeletal Survey: A series of radiographs including lateral views of the skull, spine (cervical, thoracic, lumbar, sacrococcygeal), chest, pelvis, humeri, femurs, tibias, fibulas, radii, and ulnae, and anteroposterior views of all long bones and ribs
Specific views may be added based on initial findings
CT scan: Useful for acute fractures, intracranial hemorrhage, and bony detail
MRI: Excellent for evaluating soft tissue injuries, brain edema, and older subdural hematomas
Other investigations may include complete blood count (CBC), coagulation profile, liver function tests (LFTs), and urine drug screen if indicated.
Differential Diagnosis:
Accidental trauma (falls, birth injuries), metabolic bone diseases (rickets, osteogenesis imperfecta), bleeding disorders (hemophilia, von Willebrand disease), infections (osteomyelitis), and congenital bone abnormalities
Metaphyseal lesions, however, are rarely explained by these conditions.
Skeletal Survey Specifics
Purpose:
To detect occult fractures, identify patterns of injury suggestive of abuse, and assess the extent of skeletal trauma.
Timing:
Typically performed within 24-48 hours of suspicion of NAT.
Key Findings Indicative Of NAT:
Metaphyseal fractures (corner fractures, bucket-handle fractures)
Rib fractures (especially posterior and multiple)
Scapular fractures
Spinous process fractures
Epiphyseal separations
Fractures in different bones and different stages of healing.
Interpretation:
Requires expertise in pediatric radiology
A radiologist experienced in child abuse imaging should interpret the survey
Correlation with clinical findings is paramount
Even seemingly minor fractures can be significant in the context of NAT.
Metaphyseal Lesions Details
Anatomy:
The metaphysis is the area of long bones between the epiphysis and the diaphysis, containing the physis (growth plate)
It is rich in blood vessels and less ossified in infants, making it vulnerable to shearing forces.
Types Of Metaphyseal Fractures:
Corner fractures (transphyseal extension with avulsion of metaphyseal bone)
Bucket-handle fractures (similar to corner fractures but often more extensive)
Avulsion fractures of the periosteum
Torsional fractures
Fractures through the physis.
Mechanism Of Injury:
Caused by forceful twisting or shaking, or by violent pulling on an extremity, leading to shearing forces that pull off fragments of the developing bone at the metaphysis.
Radiographic Appearance:
Often characterized by subtle lucent lines or fragments within the metaphysis, typically adjacent to the physis
May appear as a triangular fragment or a "bucket handle" shape on lateral radiographs
Can be mistaken for normal variants or other pathology if not recognized.
Management
Initial Management:
Immediate medical evaluation and stabilization
Ensure the child is safe and protected from further harm
Notify child protective services (CPS) or relevant authorities immediately
Multidisciplinary approach involving pediatrics, radiology, social work, and law enforcement.
Medical Management:
Supportive care for any injuries sustained
Pain management
Nutritional support
Management of complications such as seizures or intracranial bleeding.
Legal And Social Aspects:
Reporting to authorities is a legal and ethical obligation
Cooperation with CPS and law enforcement is crucial for child safety and investigation
Documentation of all findings is vital for legal proceedings.
Follow Up:
Long-term follow-up for physical and psychological well-being of the child
Ongoing support for the child and any siblings
Therapeutic interventions for trauma-related sequelae.
Key Points
Exam Focus:
Recognize metaphyseal lesions as a hallmark of nonaccidental trauma
Understand the components and purpose of a skeletal survey
Be aware of the typical age group affected by metaphyseal fractures
Know the reporting obligations for suspected child abuse.
Clinical Pearls:
Maintain a high index of suspicion for NAT, especially with vague or inconsistent histories
Always perform a complete skeletal survey when NAT is suspected
Never dismiss a history that is inconsistent with the injury
Remember that even small fractures can be significant
Thorough documentation is critical.
Common Mistakes:
Failing to order a skeletal survey
Misinterpreting subtle metaphyseal fractures
Accepting implausible histories without further investigation
Delayed reporting to child protection agencies
Inadequate documentation of findings.