Elda Baptistelli de Carvalho, MD, PGY-3 University of Toronto Cervical Spine Trauma Elda Baptistelli de Carvalho, MD, PGY-3 University of Toronto

Objectives Clinical indication for each imaging modality Identify anatomy of cervical spine Approach to C-spine radiography interpretation Classification of spine injuries

Who gets radiographs? Midline cervical tenderness Focal neurologic deficits Altered LOC Evidence of intoxication Painful distracting injury

Who gets CT? Dangerous mechanisms/high energy mechanisms: -fall from elevation = or > 3 feet/5 stairs -axial load to head (diving) -MVC high speed (>100 km/h), ejection -motorized recreational vehicles -bicycle collision

Who gets MRI? Unexplained neurologic symptoms/signs For visualizing soft tissues, neural elements and unsuspected disk herniation To differentiate cord edema x hemorrhage x infarction To better characterize epidural hematoma

Anatomy

Approach to C spine radiograph ABC’S -Adequacy

Approach to C spine radiograph ABC’S -Adequacy

Approach to C spine Radiograph ABC’S -Alignment

Approach to C spine Radiography ABC’S - Bones

Approach to C spine radiograph ABC’S - Cartilage

Approach to C spine radiograph ABC’S -Soft Tissue Rule 2-6 (C2-6 mm) 6-2 (C6-2 cm)

Case 1

Case 1

Mechanism of Fractures Hyperflexion Hyperextension Axial Compression

Classification

Classification By Mechanism of injury /Stability Type of Injury Fractures Stability Flexion Anterior subluxation  Unilateral facet dislocation Bilateral facet dislocation Wedge compression fracture Flexion teardrop fracture Clay Shoveler's fracture Odontoid stable or delayed instability stable unstable stable unstable stable unstable Extension Hangman's fracture  Compression Jefferson fracture Burst fracture unstable stable

Hyperflexion

Case 2

Clay shoveler fracture Stable fracture Hyperflexion ( shoveling snow) Sudden exertion of muscular attachment Avulsion # of spinous process of C7>C6>T1 Rule out extension to lamina, facet #, unilateral jump facet

Case 3

Unilateral Facet Dislocation Hyperflexion + rotation Superior facet slides over inferior facet and becomes locked Anterior subluxation of superior vertebral body –25% AP diameter Stable injury 30% with associated neurologic deficit MRI: disk extrusion leading to cord compression

Case 4

Bilateral Facet Dislocation Extreme hyperflexion Anterior dislocation of articular masses (disruption of posterior ligament complex,PLL,disk and ALL. Complete dislocation: dislocated vertebra anteriorly displaced ½ of AP diameter of vertebral body Unstable ( high incidence of cord damage)

Case 5

Case 6

Flexion Tear Drop Flexion+compression (MVA) Teardrop fragment comes from the anteroinferior aspect of the vertebral body Larger posterior part displaced backward into the spinal canal Facets joints and interspinous distances usually widened, disk space may be narrowed 70% of patients with neurologic injuries Unstable fracture (complete disruption of ligaments and anterior cord syndrome)

Hyperextension

Case 7

Hangman’s fracture Most common cervical spine fracture Usually hyperextension Diving Unstable, however seldom associated with cord injury (AP diameter of spinal canal greatest at C1/C2 level and # pedicles allow decompression) Hangman’s + uni/bilateral facet dislocation: high rate of neurologic complications

Types of Hangman #

Case 8

Hyperextension injury Widening of disk space anteriorly and narrowing posteriorly “open book” Central cord injury= disproportionated weakness in arms and normal strength in the legs Injuries can be devastating, however are uncommon hemorrhagic

Case 9

Extension Teardrop Fracture ALL pulls bony fragment away from inferior aspect of the vertebra because sudden extension Fragment is true avulsion x fragment from flexion teardrop (compression) Diving accidents Lower cervical spine Central cord syndrome (buckling of ligamenta flava into spinal canal) Stable in flexion; highly unstable in extension

Case 10

Axial Compression

Jefferson Fracture Burst fracture of ring of C1 Axial loading in the occiput No associated neuro deficts ( C1 ring is wide!) Diving, MVA, fall onto height > 2mm dislocation of lateral masses of C1 or odontoid view is diagnostic, 1-2 mm is equivocal ( rotation of head?) Predental space > 3 mm: disruption of transverse ligament 1/3 associated with C2 fracture

Case 11

Atlanto-Occipital Dislocation Very rare in surviving patients More common in Kids Hyperextension+distraction Disruption of tectorial ligaments CR: rule of 12: tip of dens-basion Basion-post line< 12mm Atlanto-occipital condyle distance<5mm

Summary Be systematic (follow ABC’S!!!!) Know anatomy and mechanism of trauma If dangerous mechanism-CT Unexplained neuro symptoms-MRI Don’t clear C spine on call if not sure!!

References http://www.wheelessonline.com/ortho http://www.radiologyassistant.nl http://www.learningradiolgy.com http://www.radiographics.rsnajnls.org Emergency Radiology-Schwartz Primer to Diagnostic Imaging