Originally published at Pediatric EM Morsels on February 8, 2019. Reposted with permission.

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Oh, once again, Homer is correct! Physics does matter. As does Anatomy and Physiology with respect to caring for children. We’ve previously discussed how these aspects have significance when evaluating ill and injured children (ex, Thoracic Trauma, Abdominal Trauma), but a recent post on the hazards of children sitting in the front seat of cars has brought to mind another condition that warrants specific consideration Pediatric Cervical Spine Injury. With adults it is relatively straight forward; apply your favorite validated screening tool and if your patient needs imaging, obtain a CT. With children, it isn’t as “simple.” Fortunately, my friend and colleague, Dr. Emily MacNeill has spent some time pondering this and can help us decipher the issue of Pediatric Cervical Spine Injury:

Cervical Spine Injury: Basics

• Fortunately, cervical spine trauma is rare in children! [Gopinathan, 2018; Leonard, 2014]
  • Accounts for only 1-10% of all spinal injuries.
  • Of pediatric spinal injuries, however, the cervical spine is involved in 60-80% of the time.

• The majority of c-spine injuries in children occur between the Skull and C4! [Gopinathan, 2018]
  • Many involve C1 and C2.
  • Atlanto-Axial injuries are more common in children than adults

• Age-related Mechanisms
  • Young infants and Toddlers (Can’t protect themselves)
    • Motor Vehicle Collisions
      • Most common
      • Often related to inappropriate restraint.
    • Falls
  • School age children and Adolescents (Put themselves in harm’s way)
    • Motor Vehicle Collisions
    • Sport-Related Injuries become very prevalent [Babcock, 2018]
      • Higher Risk Sports:
        • Diving
        • Football, Hockey
        • Gymnastics, Cheering
        • Trampoline!
        • Non-motorized vehicle crashes (ex, BMX)
      • Non-organized “Rough Play” around the house is also found to be a risk factor.
  • Non-accidental trauma is also, sadly, a well known mechanism.

Cervical Spine Injury: Anatomy Matters

• Young Child Anatomy & Injury Predisposing Characteristics: [Gopinathan, 2018; Baumann, 2015; Leonard, 2014]
  • Relatively larger head size to body
    • Leads to Higher fulcrum
    • Leads to Higher cervical spine level of injury
  • Elastic / Flexible spinal column
    • The spinal column can be distracted by 5cm without structural injury.
    • Unfortunately, the Spinal Cord cannot!
    • Leads to Spinal Cord Injury Without Radiographic Abnormality (SCIWORA) – so imaging the bones may not be good enough.
  • Poor Musculature – less protection
  • Open Ossification Centers
    • Can make interpretation of images more challenging (just like that elbow film)
      • The Atlas vertebrae has 3 ossification centers that don’t fuse until 7 years of age.
      • The Dens has 2 ossification centers that don’t unite until 5-7 years of age.
    • Can have growth plate injuries!
  • Horizontally oriented vertebral facet joints and Physiologic Wedging of the vertebral bodies – greater incidence of dislocation!

• As a child matures, the above factors alter changing of the Fulcrum position over time. [Gopinathan, 2018; Baumann, 2015]
  • Infant: ~C2-C3
  • 5 yo: ~C3-C4
  • 10 yo: ~C4-C5
  • Adult: ~C5-C6

• Pediatric patients are often characterized in studies as belonging to one of 3 groups with respect to cervical spine evaluation:
  • < 3 year olds
  • 3 – 8 year olds
  • 9 – 17 year olds

Cervical Spine Injury: Conundrum

• Evaluation of pediatric c-spine is challenging!!
  • Spinal cord injury is rare in children overall.
  • Young children cannot communicate effectively.
  • It is known that children with C-spine injury can, occasionally, be asymptomatic initially. [Gopinathan, 2018; Hale, 2015]
  • Mechanisms and Anatomy change with age.
  • C-Spine clearance “Rules” for Adults do NOT fit all children well. [Gopinathan, 2018; Slaar, 2017; Baumann, 2015]
    • NEXUS – only 1.3% of spine injuries in study were in kids 8 years or younger, but does perform well in 9-17 year olds!
    • Canadian C-Spine Rule – included NO patients <16 years
    • Both have been studied retrospectively and can perform reasonably well for older children.
  • PECARN C-spine Injury Risk Factors have not yet been validated.
    • 8 Risk Factors (when ALL absent, 98% sensitive). [Leonard, 2011]
      • Altered Mental Status
      • Focal Neurologic Findings
      • Substantial Torso Injury
      • Neck Pain
        
      • Torticollis
      • Conditions Predisposing to Cervical Injury
      • Diving
      • High-Risk Motor Vehicle Crash
  • Plain Films are decently sensitive for young children. [Cui, 2016; Nigrovic, 2012]
  • CT imaging images the bones better, but injury in children is often not bony so they add unnecessary radiation to the equation.
  • SCIWORA exists!
  • MRI is costly and often requires sedation.

• Simply put… we are not going to be 100% sensitive… but let’s not be defeatist.
  • Consider High Risk Mechanisms: [Gopinathan, 2018; Baumann, 2015]
    • High Risk Motor Vehicle Collision (fatality, rollover, speed >55mph, ejection, head-on collision)
    • Diving (or axial load) injury
    • Fall > 10 feet
    • Non-Accidental Trauma
  • Consider Patient Specific Risk Factors (ex, Down’s Syndrome and other Musculoskeletal disorders) [Gopinathan, 2018]

Cervical Spine Injury: Proposed Evaluation

• Children < 3 years of age
  • Obtunded? – Obtain CT +/- MRI
  • Alert?
    • If Normal Exam and Low Mechanism
      • Do a thorough exam!
      • Discuss low risk with family.
      • Consider clearing clinically or with plain films [Cui, 2016; Nigrovic, 2012]
    • If Neurologic abnormality – Obtain MRI
    • Obtain CT if: Torticollis, Substantial Torso Injury, High Risk Mechanism, Not Properly Restrained, Predisposing Patient Factors (ex, Down’s Syndrome), or obtaining head CT.

• Children 3 – 8 years of age
  • Obtunded? – Obtain CT +/- MRI
  • Alert?
    • Apply NEXUS (or PECARN).
      • If negative, remove collar.
      • If positive, Neuro symptoms (ex, hands “burning”) or findings? Then MRI!
      • If positive, but no Neuro symptoms / findings, consider Plain Films or LIMITED CT (from skull to C3). [Hannon, 2015; Nigrovic, 2012]

• Children 9 years and older
  • Obtunded? – Obtain CT +/- MRI
  • Alert?
    • Apply NEXUS or Canadian. [Slaar, 2017; Baumann, 2015]
    • If positive, Neuro symptoms (ex, hands “burning”) or findings? Then MRI!
    • If positive, but no Neuro symptoms / findings, consider Plain Films or CT.

Moral of the Morsel

• Anatomy Matters! The spinal column is more flexible than the spinal cord! Don’t overlook SCIWORA and those subtle neurologic symptoms.
• Physics Matters! That fulcrum is really high for the very young, and gradually moves caudally… consider limited CT (skull to C3) for 3-8 year olds who you want to CT.
• Plain films are still en vogue! You can use them to screen low risk patients.
• CTs are of less value in the very young!
• Have a plan! Since there is no validated strategy for clearing children’s c-spine, it is good to have an institutional plan!

References