Paediatric spinal trauma

Introduction

• Comprises only 5-10% of all spinal injuries
• Mortality 25-30% (higher than adults)
• 5% of children with severe TBI will have cervical spine trauma
• 1% of children with spine injury have spinal cord injury
• SCIWORA is almost exclusive to children and comprises 20-60% of SCI
  • Associated with high incidence of complete neurological deficit
• Spinal injury <10yo usually involves C1/2 with atlanto-axial rotatory subluxation, bony or ligamentous injuries, or SCIWORA and severe cord injury
  • In children <8yo, 80% occur at C1-3
  • Thoracolumbar junction is next most common

• 30% have fractures at multiple levels (5-15% of these are in different regions)
• Atlanto-axial rotatory subluxation rarely has spinal cord injury
• Ligamentous injury is more likely than high spinal fracture to have neurological impairment
• As bony spine matures, adult-like lower cervical and thoracic injuries are more commonly seen

Clues to diagnosis

• Flaccid, immobility and areflexia below level (spinal shock)
• Hypoventilation with paradoxical chest movement
• Apnoea with rhythmic alae nasi flaring (Duncan’s sign)
• Hypotension with inappropriate bradycardia and cutaneous vasodilatation below level
• Priapism
• Spinal shock resolves over 3-5 days with gradual regaining of reflexes (anal/bulbocavernosus usually first)

Development of the spine

• Large amount of cartilage in paediatric cervical spine makes assessment difficult
• Atlas
  • Ossifies from three ossification centres: 2 in lateral masses and 1 for the body
  • Body ossfies at 1 year of age, posterior arches fuse at age 3-4
• Axis
  • Ossifies from 7 ossification centres
    • 5 primary: 2 for odontoid, 2 for lateral masses and 1 for body
    • Dense is fused at birth normally
    • Odontoid-body fusion occurs at 3-6yo
    • Tip of odontoid ossifies at age 3 and fuses by age 12
• Rest of cervical vertebrae
  • 3 primary ossification centres (body and 2 neural arches) and 2 secondary ossification centres (ring apophyses)
  • Vertebral bodies wedge-shaped until age 7 when they square off
• Thoracic and lumbar vertebrae develop similarly to cervical vertebrae

Physiology of neck

• Fulcrum of neck is C2-3 in infant, C3-4 by age 6 and C5-6 by age 8
• Relatively large head and weak muscles
• Laxity of ligaments and joint capsules
• Relatively horizontal positioning of facet joints with underdevelopment of uncinate processes

Indications for spinal immobilisation

• ALOC
• Inability to give pain hisory
• Neck or back pain
• Neurological signs or symptoms
• Multitrauma
• Hx of significant trauma – Fall >3m, pedestrian or cyclist vs. car, unrestrained MVA passenger or crash diving accident, MVA >60km/hr, kicked/fall from horse, severe electric shock, thrown from vehicle
• History of spinal abnormality
• Using hands to support neck
• Traumatic torticollis
• Substance affected

Spinal immobilisation

• Off spinal board immediately and onto Thoracic Elevation Device (TED) on normal bed

Cervical spine injuries

• Flexion
  • Flexion teardrop fracture – Very unstable
  • Bilateral facet joint dislocation – Unstable
  • Atlanto-occipital dislocation – Unstable
  • Displaced odontoid fracture – Unstable
  • Anterior subluxation – Unstable
  • Anterior wedge fracture – Stable
  • Clay-shoveller’s fracture – Very stable

• Extension – Buckling of ligamentum flavum into posterior spinal canal can cause central or posterior cord syndrome
  • Atlantoaxial dislocation – Very unstable
  • Hangman’s fracture C2 – Unstable
  • Extension teardrop fracture – Unstable in extension
• Rotation
  • Rotary atlantoaxial dislocation – Unstable
  • Rotary atlantoaxial subluxation – Stable
  • Unilateral facet dislocation – Stable
• Vertical compression
  • Jefferson fracture (C1 burst) – Very unstable
  • Burst fracture vertebral body – Stable

Clinical assessment (Cameron)

• If verbal
  • If no midline bony pain or neurological symptoms (even if resolved) or signs, remove collar and allow to turn head left/right
  • If this produces pain, replace collar and obtain X-rays
  • If no pain or neurological symptoms with movement to left and right – clinically cleared
• If preverbal
  • If no tenderness/distress, remove collar and allow spontaneous movement
  • If moving neck without discomfort, clinically cleared

Imaging

• Need AP, lateral and odontoid view
  • Can exclude odontoid view if <5yo as difficult to achieve mouth opening and does not increase likelihood of missed fracture
• CT
  • Primarily to delineate abnormalities on plain films or areas not adequately visualised on plain films
  • Assessment in unconscious patients with normal initial X-ray
  • If having CT of brain
• MRI
  • Imaging method of choice for ligamentous injury and spinal cord injury itself

X-ray interpretation

• Normal findings
  • Pseudosubluxation C2 on C3 (seen in 25% of children)
    • Should be <5mm (look at other spinal lines)
  • Exaggerated atlantodens distance (20% of children <8yo)
  • Radiolucent synchrondrosis between odontoid and C2 (all children under 4 and 50% of those under 10)
    • Can be confused with fracture and vice versa
  • Variable anterior soft tissue width
  • Anterior wedging of vertebral bodies (esp. C3)
  • Apical odontoid epiphysis – Appears at 7 years and fuses at 12yo
  • Absent lordosis
  • Retropharyngeal space should be <1/2 vertebral body width at C2 and no wider than full width of C6
    • >7mm opposite C2 is abnormal

• Atlantoaxial relationship
  • Distance on lateral film from posterior border of anterior arch of C1 to anterior margin of odontoid should be <5mm in children <8yo and <=3mm in older children/adults (<2mm on CT)
• Atlanto-occipital relationship
  • Harris’s posterior axial line should lie within 12mm of the basion of the skull
• Swischuk’s line for pseudosubluxation
  • Line from anterior aspect of C1-3 spinous proceeses 
  • Anterior aspect of C2 spinous process should lie within 2mm of this line

Schwishuk

X-ray interpretation

• After X-rays are examined and normal, re-examine patient and if normal, can remove immobilisation
• If still significant pain or tenderness or neurology, CT of entire spine should be performed
• If this is normal and patient alert/cooperative, keep immobilisation in place until flexion/extension views obtained 3-7 days later and liaise with spinal team

Atlanto-axial rotary subluxation

• Fixed rotary subluxation is common in childhood
• Can present after minor trauma, often in conjunction with URTI
• Presents with head turned to one side and inability to turn head past midline
• Spasm of SCM on side to which head is turned (ipsilateral) as muscle is trying to right the neck rather than causing the turn
• In contrast, in wry neck, SCM spasm is contralateral to side head is turned with spasm causing head to turn
• Often spontaneously reduces if of short duration
• If does not reduce within days, may need manipulation with post-reduction immobilisation

Thoracolumbar injuries

• Thoracic and thoracolumbar junction injuries have higher incidence of neurological deficit (up to 40%)
• Multiple level injuries seen in 30-40%
• Associated small bowel and visceral injury in 50% of cases
• Absence of pain does not exclude injury
• Any patient with pain or tenderness over the spine warrants plain imaging first
• Any child with prevent spine fracture needs entire spine imaged with plain films at minimum
• Difference in height of 3mm is pathological on lateral view

• Signs of instability
  • Vertebral body collapse with widening of pedicles
  • >33% compromise of spinal canal by retropulsed fragments
  • Translocation of >2.5mm between vertebral bodies in any direction
  • Bilateral facet joint dislocation
  • >50% anterior compression of vertebral body associated with widening of interspinous space

Spinal cord injury

• MRI findings
  • Cord transection and major haemorrhage – Poor outcome
  • Minor haemorrhage and oedema – Moderate to good outcome
  • Normal MRI – Associated with complete recovery
• Methylprednisolone of unclear benefit and is spinal surgeon specific

SCIWORA

• Objective signs of myelopathy due to trauma with no evidence of fracture or ligamentous instability on X-rays or tomography
• Mostly in children <8yo and in cervical cord injuries
• 1-10% of all spinal injuries
• Younger children tend to have more profound neurological injury and less long-term improvement
• Can cause delayed presentation with minor neurological deficits progressing to complete paralysis over up to 4 days – hence any vague neurological symptomatology is treate as potential cord injury

RANZCR guidelines

• NEXUS
  • Initially had very few paediatric patients
  • Follow-up validation by Viccellio et al. (2001) did not miss any cervical spine injuries with 20% fewer radiological examinations
  • Erlich (2009) retrospectively validated NEXUS in 108 paediatric patients with sensitivity of only 43%
  • Overall, use of NEXUS should proceed with caution given contradictory results of validation studies
• Canadian C-spine rule validated for >16yo

• One or more of below 98% sensitive and 26% specific for cervical spine injury
  • Altered mental status
  • Focal neurological deficit
  • Complaint of neck pain
  • Torticollis
  • Substantial torso injury
  • Diving
  • High risk MVA
  • Predisposing condition (Down syndrome, RA, RIckets, Osteogenesis imperfecta, Klippel-Feil disease, Ehlers-Danlos, Achondroplasia, Marfans, Renal osteodystrophy)

Last Updated on October 13, 2021 by Andrew Crofton