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C SPINE Y A Mamoojee Importance of Prompt Diagnosis • Neck pain – > quadriplegia – > death • Delayed recognition can lead to irreversible s.c injury and permanent neurologic damage. INDICATIONS • Who needs XR NEXUS NO • Alcohol intoxication • Focal neuro deficit • Midline tenderness • GCS 15 • Painful distracting injuries CANADIAN C SPINE RULES CASE DISCUSSION • A person arrives by ambulance to ED on a backboard and a cervical collar after an MVA. • Speed of 50km/hr • No LOC, no other injuries, no midline tenderness, BAL 0.20. • Does he need imaging? WHAT VIEWS? • LATERAL • AP • ODONTOID • SWIMMERS • FLEXION/EXTENSION? ANATOMY OF NECK • • • • LIGAMENTS BONES MUSCLES JOINTS • • • • • • • • • Most important view Can see 80-90% of injuries Interpretation: A - adequacy A - alignment B - bone C - cartilage D - disc S – soft tissue • • • • • A - Must have a view of C7 – T1 A - Use 3 lines 1. anterior vertebral line 2. posterior vertebral line 3. spino laminar line (base of spinous processes) 4th line can be used ie. Tips of spinous processes • • Check : • B - individual vertebrae • C - cartilage • D - disc • S - soft tissue • <7mm at C3 • <21mm at C7 • no more than vertebral body width at C7 • Predental space – • 5mm child • 3mm adult • Fanning of spinous processes • Open mouth view • Adequate if entire Odontoid and lateral borders of C1 and C2 visible • Check : • lateral masses of C1 must align with Odontoid • bilateral symmetry • Important also for Odontoid fractures SWIMMER’S AP MECHANISM OF INJURY • • • • • 1. Flexion 2. flexion rotation 3. extension 4. axial compression 5. Other WEDGE FRACTURE • STABLE • Compression fracture resulting from flexion • Features – – Buckled anterior cortex – Loss of height of anterior part of body – Anterosuperior fracture of vertebral body FLEXION TEARDROP FRACTURE • UNSTABLE • Posterior ligament disruption and anterior compression fracture of the vertebral body • Prevertebral swelling • Tear drop fragment • Posterior vertebral body subluxation into the spinal canal • Spinal cord compression • Fracture of spinous process • Mechanism – Hyperflexion and Compression – Excessive flexion of the neck in the sagittal plane, disrupts posterior ligament. • Example – diving into shallow pool ANTERIOR SUBLUXATION • Disruption of the posterior ligament complex. Anterior subluxation of C4 on C5 is characterized by widening of the interspinous space (arrowhead), subluxation of the C4-C5 interfacetal joints (arrows), and anterior rotation of the C4 vertebra relative to C5. • • • Stable but potentially unstable during flexion Mechanism : hyperflexion Disruption of posterior ligament complex, anterior intact • • • • Stable – loss of normal cervical lordosis anterior displacement of body fanning of interspinous distance • • • Unstable – anterior subluxation >4mm assoc. compression fracture >25% of affected body increase or decrease in normal disc space fanning of interspinous distance • • BILATERAL FACET JOINT DISLOCATION • Complete anterior dislocation of the vertebral body • Mechanism – extreme hyperflexion of head and neck without axial compression • Unstable – very high risk of cord damage • Features – – complete anterior dislocation >50% of vertebral body diameter – Disruption of the posterior ligament complex and anterior longitudinal ligament – “Bow tie” appearance of the locked facets. CLAY SHOVELLER’S FRACTURE • Fracture of spinous process C6-T1 • Mechanism – powerful hyperflexion, usually combined with contraction of paraspinous muscles pulling on spinous processes (e.g. shovelling). Features – spinous process fracture on lateral view Ghost sign on AP – double spinous process of C6/C7 due to displaced fractured spinous process UNILATERAL FACET JOINT DISLOCATION • Stable • Mechanism – simultaneous flexion and rotation • Facet joint dislocation and rupture of the apophyseal joint ligaments • FEATURES : • Anterior dislocation of vertebral body by <50% of the diameter • Discordant rotation above and below involved level • Facet within intervertebral foramen on oblique view • “Bow tie” appearance of the overriding locked facets EXTENSION INJURIES • Excessive extension of the neck in the sagittal plane. • E.g. hitting the dash board in MVA HANGMAN’S FRACTURE • • • • Fractures through pars interaticularis of the axis Unstable if occurs with facet dislocation Mechanism – hyperextension Features – – Prevertebral soft tissue swelling – Avulsion of anterior inferior corner of C2 assoc. with rupture of the ant. Longitudinal ligament – Anterior dislocation of C2 body – Bilateral C2 pedicle fractures. C1 POSTERIOR ARCH FRACTURE • Hyperextended head • C1 arch is compressed by occiput and C2 spinous process • Odontoid process is normal • Stable • Distinguish from Jefferson fracture (unstable) AXIAL COMPRESSION INJURIES BURST FRACTURE • Fracture of C3-C7 that results from axial compression • Spinal cord injury secondary to displacement of posterior fragments is common. • Mechanism – Axial compression • >25% loss of height of vertebral body • Stable • Needs CT or MRI JEFFERSON FRACTURE • Burst type fracture of C1 • Lateral displacement of C1 masses • Fracture of anterior and posterior arches on both sides – quadruple fracture • Unstable – transverse ligament rupture • Soft tissue swelling is marked on Xray ATLANTO AXIAL SUBLUXATION • Flexion and rotation causes the transverse ligament to rupture • Predental space >3.5mm in adults and >5mm in children • Unstable ODONTOID FRACTURES • 3 Types : – I Avulsion of tip at alar ligament (stable) – II Base of dens (unstable) – common, non union is a complication – III Involves body of C2 (unstable)