This document provides an overview of cervical spine injuries and key considerations for their radiological evaluation. It discusses important anatomical structures, mechanisms of injury, classifications of common fractures like Jefferson fractures and Hangman's fractures, criteria for stability versus instability, and special considerations like SCIWORA in pediatric populations. A wide range of cervical spine pathologies are addressed.

1. C-Spine Injury Radiology Challenge

2. Adequacy Skull base C1-C7 Upper T1

3. Alignment Anterior spinal line Posterior spinal line Spinolaminal line Spinous process tips

4. Bones Anterior components Vertebral body (cortices, endplates) Transverse process Posterior components Articular masses and pedicles Facet joints Lamina Spinous process

5. Cartilage Intervertebral discs Epiphyses (childhood) Subdental synchondrosis Ossification centers (childhood) Tapered anterior vertebrae Absent C1 anterior ring

6. Soft Tissue Cervicocranial Pd : Adenoid hypertrophy Predental Ad : < 3mm Pd : < 5mm Prevertebral Ad : C3 < 5-7mm; C5 < 15-21mm (1 body) Pd : C3 < 7mm; C5 < 14mm (2/3 body)

7. Mechanism of Injury Types of c-spine injuries Axial loading Flexion Extension Rotation Lateral bending Distraction.

8. Jefferson fracture (C1) Blowout of the ring Axial loading Open-mouth (odontoid) view 1/3 associated with C-2 fracture Unstable Usually not associated with cord injury Lateral offset of C1 lateral masses > 1mm from C2 vertebral body

9. Pseudo-Jefferson fracture Age < 4Y 90% (+) at 2 Y C1 growth > C2; radiolucent cartilage Normalizes by 4-6 Y CT scan needed

10. C-1 Rotary Subluxation Odontoid not equidistant from lateral masses Children Torticolis (chin toward uninvolved side) Immobilize in place Consult NS

11. C-2 Odontoid Subluxation Ruptured transverse ligament Odontoid fractures Predental space : Ad > 3mm Pd > 5mm (symptomatic if > 7-10mm) C1 spinal canal (Steel rule of 3) : Odontoid – Free space – Cord Unstable

12. C2 Odontoid Fractures Type I : Avulsion of tip Stable Type II : At the base Unstable D/D : Synchondrosis if < 6Y Type III : Through vertebral body Unstable

13. Hangman Fracture Traumatic spondylolisthesis of C2 Mechanism : Extension + Distraction Extension + Axial compression X-ray : C2/3 subluxation Unstable Traction contraindicated

14. C2/3 Subluxation C2 posterior spinal line v.s. Swischuk line Pseudosubluxation (< 8-16Y) : Displacement < 1.5-2 mm Hangman fracture : Displacement > 1.5-2 mm

15. Unstable Fractures Overriding of vertebra by > 3 mm Angulation > 11 degrees Flexion teardrop Bilateral facet dislocation (BFD) Atlanto-occipital dislocation Atlanto-axial dislocation (flexion/extension/rotary) Odontoid fracture Jefferson fracture/posterior arch fracture of C1 Hangman fracture

16. Stable Fractures Wedge fracture Clay shoveler fracture Transverse process fracture Unilateral facet dislocation (UFD) Burst vertebral body Isolated fracture of articular pillar Extension teardrop in flexion

17. Subluxation Angulation between two adjoining vertebrae > 11 degrees Overriding of vertebra by > 3 mm

18. Facet Dislocation Unilateral (UFD) : Stable < 25% translation Bilateral (BFD) : Unstable > 50% translation

19. Teardrop Fractures Extension teardrop : Stable in flexion, unstable in extension Cortices : Same length Flexion teardrop : Extremely unstable Cortices : Unequal length

20. Hyperextension Injury Fracture of inferior endplate, being avulsed by the Sharpey fibers Extension teardrop Bilateral facet dislocation (BFD) Severe prevertebral soft tissue swelling Anteriorly displaced NG tube

21. Burst Vertebral Body Mechanically stable Spinal cord injury can occur (even total transection)

22. Distraction Injuries Longitudinal stress (e.g. difficult delivery) Atlanto-occipital dislocation Increased space between occiput and C1 Widening of IV disk without adjacent compression fracture MRI

23. Spinal EDH Venous bleeds Minor traumas Ascending neurologic symptoms Hours or days MRI

24. SCIWORA 67% of pediatric SCI Mainly < 8 Y Plain films/tomograms/CT (-) May have transient neurologic symptoms and apparently recover then return 1d later with significant neurologic abnormalities Poor prognosis

25. SCIWORA Etiology : Vascular injuries (occlusion, spasm, infarction) Ligamentous injury Disc impingement Incomplete neuronal destruction

26. Oblique C-spine Pedicles Articular mass Intervertebral foramen Transverse process Laminae - aligned in the fashion of shingles