Cervical Spine Injuries (Acute)

== Anatomy ==
File:Atlas-axis.png
File:Axis.png
File:C-spine lateral.png
File:C-spine xray.png
== Flexion Injuries ==
=== C1/C2 ===
* Atlanto-occipital dislocation , atlantoaxial dislocations , potentially associated with odontoid fracture.
* Imaging: Basion-dens interval (BDI) >10mm,
* Stability: Unstable.
=== Wedge fracture ===
* Stretch on strong nuchal ligament transmits force to vertebral body.
* Stability: Generally stable unless >50% compression or multiple contiguous.
=== Flexion-teardrop fracture ===
* Severe flexion force, avulsion of fragment of anterior/inferior portion of vertebral body.
* Stability: Unstable, involves anterior/posterior ligamentous disruptions.
=== Clay shoveler’s fracture ===
* Oblique fracture of spinous process of lower cervical spine.
* Stability: Stable
=== Subluxation ===
* Pure ligamentous injury without associated fracture.
* Imaging: Widening of interspinous and intervertebral spaces on lateral.
* Stability: Potentially unstable.
=== Bilateral facet dislocation ===
* Anterior displacement of spine above level of injury caused by dislocation of upper inferior facet from lower superior facet.
* Imaging: Anterior displacement greater than ½ AP diameter of vertebral body.
* Stability: Unstable
=== Odontoid process fracture ===
* Head trauma with shear force directed at odontoid.
* Sub-classification: Type I (above transverse ligament), type II (odontoid base), type III (extension to body of C2)
* Stability: Types II, III unstable.
File:Atlantoaxial dislocation.png|Atlantoaxial dislocation
File:Atlanto-occipital dislocation.png|Atlanto-occipital dislocation
File:Wedge.png|Wedge fracture
File:Flexion teardrop.png|Flexion teardrop fracture
File:Clay shoveler.png|Clay shoveler fracture
File:Facet dislocation.png|Facet dislocation
File:Dens fractures.png|Odontoid process fracture
== Flexion/Rotation Injuries ==
=== Rotary atlantoaxial dislocation ===
* Imaging: Open-mouth odontoid, asymmetric lateral masses of C1.
* Stability: Unstable
=== Unilateral facet dislocation ===
* Flexion and rotation centered around single facet results in contralateral facet dislocation.
* Imaging: AP radiograph shows spinous processes above dislocation displaced from midline, lateral radiograph shows anterior displacement of lower vertebra (less than ½ AP diameter of vertebral body).
File:Unilateral facet.png|Unilateral facet dislocation
== Extension Injuries ==
=== Posterior neural arch fracture (C1) ===
* Forced extension causes compressive force on posterior elements of C1 between occiput and C2.
* Stability: Unstable
=== Hangman’s fracture (spondylolysis C2) ===
* Abrupt deceleration causes fracture of bilateral pedicles of C2, potentially with associated subluxation. Rarely associated with SCI due to large diameter of neural canal at C2.
* Imaging: May be associated with retropharyngeal space edema.
* Stability: Unstable
=== Extension-teardrop fracture ===
* Abrupt extension (ex. diving) results in stretch along anterior longitudinal ligament with avulsion of anterior/inferior fragment of vertebral body (usually C5-C7).
* Imaging: May be radiographically similar to flexion-teardrop fracture.
* Complications: Central cord syndrome
* Stability: Unstable in extension
File:Posterior arch fracture.png|Posterior neural arch fracture
File:Hangman-fracture.png|Hangman's fracture
File:Extension teardrop.png|Extension-teardrop fracture
== Vertical compression ==
=== Burst fracture ===
* Force applied from above or below causes transmission of force to intervertebral disc and vertebral body.
* Imaging: Comminuted vertebral body, >40% compression of anterior vertebral body.
* Complications: Fracture fragments may impinge on spinal cord.
* Stability: Stable
=== Jefferson fracture (C1) ===
* Vertical force transmitted from occipital condyles to superior articular facets of atlas, resulting in fractures of anterior and posterior arches.
* Imaging: Widening of predental space. Open-mouth odontoid view may reveal bilateral offset distance of >7mm between lateral masses of C1/C2.
* Stability: Unstable
File:Burst.png|Burst fracture
File:Jefferson.png|Jefferson fracture
== References ==
# MD RK, MD BED, CAQ-SM KHM, MD WF. Emergency Department Evaluation and Treatment of Cervical Spine Injuries. Emergency Medicine Clinics of NA. 2015;33(2):241-282. doi:10.1016/j.emc.2014.12.002.
# Denis F. Spinal instability as defined by the three-column spine concept in acute spinal trauma. Clin Orthop Relat Res. 1984;(189):65-76.
# Munera F, Rivas LA, Nunez DB, Quencer RM. Imaging evaluation of adult spinal injuries: emphasis on multidetector CT in cervical spine trauma. Radiology. 2012;263(3):645-660. doi:10.1148/radiol.12110526.
Category:Cervical Spine Conditions
Category:Fractures