Pediatric Cervical Spine Injury Risk Stratification: Rebaked Morsel

It seems like just yesterday (or maybe ~ a month ago) when we served up a tasty morsel on the PECARN decision rule for intra-abdominal traumatic injuries in children.  Our friends at the PECARN injury group have remained busy this spring with generating more externally validated clinical decision rules. In addition to the recently published low risk intra-abdominal injury validation, we have another new tool to use this summer as school breaks, underdeveloped frontal lobes, and high speeds leave us inundated with blunt trauma. Let’s take a moment to review the new information on the PECARN prediction rule for cervical spine and rebake a morsel on Pediatric Cervical Spine Injury Risk Stratification:

Pediatric Cervical Spine Injury Risk Stratification: Basics

Pediatric Cervical Spine Injury Risk Stratification: Anatomy Matters

• Young Child Anatomy and Injury Predisposing Characteristics:
  • Relatively larger head size compared to body
    • Leads to higher fulcrum
    • Higher fulcrum = higher spinal level injury
• Elastic/Flexible spinal column
  • Spinal column of young kids can be distracted by 5 cm without structural injury
  • Unfortunately, the spinal cord isn’t so resilient
    • This can lead to Spinal Cord Injury Without Radiographic Abnormality (SCIWORA) — CT may not be enough
• Poor Musculature — less protection
• Open Ossification Centers
  • Can make interpretation of plain films more challenging
  • C1 (Atlas) has 3 ossification centers, which don’t fuse until ~7 years of age 
  • The Dens of C2 (Axis) has 2 ossification centers that don’t fuse until ~5-7 years old
  • Growth plate injuries are possible
• Horizontally oriented vertebral facet joints + physiologic wedging of vertebral bodies — more prone to dislocation
• As children mature, the position of the fulcrum changes over time:
  • Infant: ~C2-C3
  • 5 yo: ~C3-C4
  • 10 yo: ~C4-C5
  • Adult: ~C5-C6

Pediatric Cervical Spine Injury Risk Stratification: The Evaluation

• Challenges:
  • Peds C-Spine injuries are rare
  • Young children can’t communicate effectively
  • Mechanisms and anatomy change with age
  • There was no all-encompassing risk stratification strategy for C-Spine injuries:
    • NEXUS Criteria – Did not include enough children 8 yo and younger to be applied
    • Canadian C-Spine Rule – Didn’t include anyone under 18
  • Clinicians were unsure which imaging to order
    • Plain film interpretation was challenging, as above
    • CT scans can add unnecessary radiation without much benefit, as C-Spine injury in children is not always bony
    • One, large population-based study demonstrated that a single CT C-Spine in childhood increased the lifetime risk of thyroid cancer by 78%
    • MRI is costly, time-consuming and may require sedation

• Use the The PECARN prediction rule for cervical spine injury to help address those challenges:
  • Can simplify the approach to the evaluation of blunt C Spine injuries in children, especially those under 8 years old.
  • In the prospective validation cohort, the risk of C spine injury was 0.2%
  • Using this decision rule would have cut down on ED CT C-spine ordering by >50% in this derivation cohort.
  • The following factors, if negative, had a sensitivity of 94.3% and NPV of 99.9% for clinically significant C Spine injuries.

Caveats to consider when using this decision rule:

• Consider other factors which were associated with high risk in PECARN’s prior retrospective derivation:
  • Diving — Odds Ratio (OR) 15 – 74
  • High-risk motor vehicle crash — OR 1.7 – 3.6
  • Predisposing conditions (Down Syndrome, Klippel-Fleil, achondroplasia, etc.) — OR 1.5 – 15
  • Torticollis — OR 1.8 – 64
• The sensitivity of C-Spine plain films in pediatric patients is good (85-95% in multiple studies), but keep in mind that nothing is 100%. If you are still concerned, do not stop there. 

Pediatric Cervical Spine Injury Risk Stratification: A Proposed Approach

Children 8 years old and less

• Apply PECARN prediction rule 
  • High Risk?
    • Perform CT Scan
  • Any factors associated with “non-negligible” risk?
    • Consider plain x ray
  • No risk factors?
    • Consider clinical clearance, reassurance, and discharge
  • If patient is obtunded and has negative imaging but a concerning mechanism?
    • Consider MRI
  • If patient has negative CT, but persistent focal neurologic complaints or exam deficits?
    • Perform MRI
  • If you are concerned but the patient is intermediate or low risk?
    • Talk to family about risks and benefits of radiation and consider CT C-Spine

Children 9-16 years old

• Apply NEXUS criteria, consider imaging if unable to clear.
• Consider MRI with focal deficits or complaints.

Children 16-18 years old

• Apply Canadian C Spine (100% sensitivity) or NEXUS Criteria (99.6% sensitivity)
• Consider imaging if unable to clear.
• Consider MRI with persistent focal deficits or complaints.

Moral of the Morsel 

• Anatomy Matters: Pediatric patients have unique C-spine anatomy, which predisposes them to different injury patterns than adults.
• When in doubt, MRI. Increased flexibility of pediatric C-spine predisposes to SCIWORA and other cord injuries. If you are concerned, get / admit for the MRI.
• Radiation? Maybe we can avoid it. C-spine CT scan is associated with an increased risk of thyroid cancer. The PECARN C Spine Prediction Rule reduced CT use by 50% in their cohort. 
• Plain films? So hot right now. While plain films for C-spine injury had previously fallen out of routine ED practice, we now have more evidence to support their use in intermediate risk patients.

References

Babcock L, Olsen CS, Jaffe DM, Leonard JC; Cervical Spine Study Group for the Pediatric Emergency Care Applied Research Network (PECARN). Cervical spine injuries in children associated with sports and recreational activities. Pediatr Emerg Care. 2018;34(10):677-686. PMID: 27749628.

Baumann F, Ernstberger T, Neumann C, et al. Pediatric cervical spine injuries: a rare but challenging entity. J Spinal Disord Tech. 2015;28(7). PMID: 26165728.

Cui LW, Probst MA, Hoffman JR, Mower WR. Sensitivity of plain radiography for pediatric cervical spine injury. Emerg Radiol. 2016; Published June 20, 2016. doi:10.1007/s10140-016-1417-y.

Easter JS, Barkin R, Rosen CL, Ban K. Cervical spine injuries in children, part I: mechanism of injury, clinical presentation, and imaging. J Emerg Med. 2011;41(2):142-150. PMID: 20493655.

Easter JS, Barkin R, Rosen CL, Ban K. Cervical spine injuries in children, part I: mechanism of injury, clinical presentation, and imaging. J Emerg Med. 2011;41(2):142-150. PMID: 20493655.

Gopinathan NR, Viswanathan VK, Crawford AH. Cervical spine evaluation in pediatric trauma: a review and an update of current concepts. Indian J Orthop. 2018;52(5):489-500. PMID: 30237606.

Leonard JC, Harding M, Cook LJ, et al. PECARN prediction rule for cervical spine imaging of children presenting to the emergency department with blunt trauma: a multicentre prospective observational study. Lancet Child Adolesc Health. 2024; Published online June 4, 2024. doi:10.1016/S2352-4642(24)00104-4.

Leonard JC, Kuppermann N, Olsen C, et al. Factors associated with cervical spine injury in children after blunt trauma. Ann Emerg Med. 2010; doi:10.1016/j.annemergmed.2010.08.038.

Leonard JR, Jaffe DM, Kuppermann N, Olsen CS, Leonard JC; Pediatric Emergency Care Applied Research Network (PECARN) Cervical Spine Study Group. Cervical spine injury patterns in children. Pediatrics. 2014;133(5)

Mathews JD, Forsythe AV, Brady Z, et al. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ. 2013;346. doi:10.1136/bmj.f2360.

Nigrovic LE, Rogers AJ, Adelgais KM, et al. Utility of plain radiographs in detecting traumatic injuries of the cervical spine in children. Pediatr Emerg Care. 2012;28(5):529-533.

Slaar A, Fockens MM, Wang J, et al. Triage tools for detecting cervical spine injury in pediatric trauma patients. Cochrane Database Syst Rev. 2017;12. PMID: 29215711.