Subaxial Cervical Spine Trauma - Orthopaedic Trauma - Lecture Slides, Slides of Orthopedics

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Subaxial Cervical

Spine Trauma

Subaxial Cervical Spine

• From C3-C
• ROM
  • Majority of cervical flexion
  • Lateral bending
  • Approximately 50% rotation

Osseous Anatomy

• Uncovertebral Joint
  • Lateral projections of body
  • Medial to vertebral artery
• Facet joints
  • Sagittal orientation 30-45 degrees
• Spinous processes
  • Bifid C3-5,? C6, prominent C

Vascular Anatomy

• Vertebral Artery
  • Originates from subclavian
  • Enters spine at C6 foramen
  • At C2 it turns posterior and lateral
  • Forms Basilar Artery
• Foramen Transversarium
  • Gradually moves anteriorly and medially from C6 to C

Neuroanatomy

• Spinal cord diameter subaxial: 8-9mm
• Occupies ~ 50% of canal
• Neural Foramen
  • Pedicles above and below
  • Facets posteriorly
  • Disc, body and uncinate process anteriorly

Ligamentous Anatomy

• Anterior
  • ALL, PLL, intervertebral disc
• Posterior
  • Nuchal Ligaments - ligamentum nuchae, supraspinous ligament, interspinous ligament
  • Ligamentum flavum and the facet joint capsules

Columns

• Holdsworth 2 column theory
  • Anterior Column
    • Body, disc, ALL, PLL
  • Posterior Column
    • Spinal canal, neural arch and posterior ligaments

Stability

“ Clinical instability is defined as the loss of the

spine’s ability under physiologic loads to

maintain its patterns of displacement, so as to

avoid initial or additional neurologic deficits,

incapacitating deformity and intractable

pain.”

White and Panjabi 1987

Stability

• Evaluation of stability should include
  • anatomic components (bony and ligamentous)
  • static radiographic evaluation of displacement
  • dynamic evaluation of displacement (controversial)
  • neurologic status (unstable if neurologic injury)
  • future anticipated loads

Diagnosis

• Physical exam
  • Palpation
    • Neck pain
      • >50% of patients with focal reproducible tenderness and negative plain films have a fracture on CT scan (Anderson, Skeletal Trauma)
    • Step off between spinous processes
    • Crepitus
  • Detailed neurologic exam

Radiographic Evaluation

• Lateral C-spine to include C7-T
• BEWARE with changing standards (many just get CT now)
• Bony anatomy
• Soft tissue detail
• Don’t forget T-L spine

Which films?

• Cross table lateral
  • Must include C7-T1 (5% of C-spine injuries)
• Three view trauma series
• Flexion/Extension
  • Controversial as to timing
  • Only in cooperative alert patient with pain and negative 3 view
  • Negative study does not rule out injury
  • If painful, keep immobilized, reevaluate

CT Scan

• Include appropriate levels
• Bony detail
• Canal compromise
• Recons can be valuable in planning

MRI Scan

• Valuable in

ligamentous injury

• Traumatic disc eval
• Can evaluate cord

directly

• Ruptured ligaments

may correlate with

findings

• Clarify neuro deficit

Missed Injuries

The presence of a single spine fracture does not preclude the inspection of the rest of the spine!

Mechanism of Injury

• Hyperflexion
• Axial Compression
• Hyperextension

Hyperflexion

• Distraction creates tensile forces in posterior column
• Can result in compression of body (anterior column)
• Most commonly results from MVA and falls

Compression

• Result from axial loading
• Commonly from diving, football, MVA
• Injury pattern depends on initial head position
• May create burst, wedge or compression fx’s

Hyperextension

• Impaction of posterior arches and facet compression causing many types of fx’s - lamina - spinous processes - pedicles
• With distraction get disruption of ALL
• Evaluate carefully for stability

Classification

• Allen and Ferguson Spine 1982
• Harris et al OCNA 1986
• Anderson Skeletal Trauma 1998
• Stauffer and MacMillan Fractures 1996
• AO/OTA Classification
• Most are based on mechanism of injury

AO/OTA Classification

• Not specific for cervical spine
• Provides some treatment guidelines - Type A - Axial loading; compression; stable - Type B - Bending type injuries - Type C - Circumferential injuries; multi-axial

Allen and Ferguson

• 165 patients
• Stability of each pattern is based on the two column theory
• Each category is broken down into stages
• Uses both mechanism and stability to determine treatment and outcome - 6 categories - Compressive flexion - Vertical compression - Distractive flexion - Compression extension - Distractive extension - Lateral flexion

Unilateral Facet Dislocation

• Flexion/rotation injury
• Painful neck
• 70% radiculopathy, 10% SCI
• Easy to miss-supine position can reduce injury!
• “Bow tie” sign: both facets visualized, not overlapping

Unilateral Facet Dislocation

• Reduce to minimize late pain, instability
• Flex, rotate to unlock; extend
• 50% successful reduction
• OR vs. halo

Unilateral Facet Dislocation

Treatment

• Nonoperative
  • Cervicithoracic brace or halo x 12 weeks
• OR approach and treatment depends on

pathology

• Anterior diskectomy and fusion w/plate
• Posterior foraminotomy and fusion with segmental stabilization