• Clinical science

Vertebral fractures

Abstract

Vertebral fractures can be caused by direct or indirect trauma and are more likely to occur in patients with decreased bone density (osteoporosis, osseous metastases). Fractures may be stable or, if there is a risk of damage to the spinal cord, unstable. Diagnosis involves a detailed neurological exam and imaging (x-ray, CT, etc). Stable fractures can be treated conservatively with analgesics and physical therapy. Unstable fractures require surgical intervention such as spinal fusion (spondylodesis), which joins vertebrae through internal fixation. Due to the close proximity to essential anatomical structures (spinal cord, blood vessels), the vertebral fractures and their surgical treatment can cause serious complications.

Epidemiology

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

References:[2]

Classification

Stability of vertebral fractures

  • Stable
    • The structural stability of the spine remains intact.
    • No neurologic deficits
    • Fractures of the anterior column of the spine
  • Unstable
    • The structural stability of the spine is compromised.
    • The spine can move as two or more independent units, which may cause spinal cord injury.
    • Mid-column and posterior column fractures

A dorsal spine injury (vertebral arches, processes, and their ligaments) is always unstable and has a high probability of spinal cord injury!

Types of vertebral fractures

  • Vertebral compression fracture (most common type)
    • Loss of height of the vertebral body due to trauma or pathological fracture
    • Progressive thoracic kyphotic deformity if multiple vertebrae are affected
    • Usually stable
    • Wedge fracture (subtype)
  • Burst fracture: fracture of the vertebra in multiple locations
    • Result of compression trauma with severe axial loading
    • Possible displacement of bone fragments into the spinal canal
  • Fracture-dislocation: : fractured vertebra and disrupted ligaments; instability may cause spinal cord compression

The degree of fracture stability is the most important feature of any spinal column injury.

Simplified Denis' three-column theory

Affected Column Affected Structures Stability
Type A Only anterior column
  • Vertebral body excluding posterior edge
  • Stable, as posterior edge is not affected
Type B Middle column also affected
  • Dorsal part of the vertebral body
  • Root of the vertebral arch
  • Posterior longitudinal ligament
  • Unstable, as the posterior edge is affected
Type C Posterior column affected

A dorsal spine injury (vertebral arches, processes, and their ligaments) is always unstable!
A fracture of the vertebral body's posterior edge has a high probability of spinal cord injury and is therefore considered unstable!

Simplified AO classification (Magerl modification)

Mode of injury Acting force Findings Stability Treatment
Type A Compression injury Flexion Vertical
  • Mostly conservative
Type B Distraction injury Flexion + Distraction Vertical
  • Surgical
Type C Translation injury Flexion + Distraction + Rotation Vertical + Horizontal

References:[3][2][4][5][6][7]

Clinical features

  • Local pain on pressure, percussion, and compression
  • Palpable unevenness or disruption of the vertebral process alignment
  • Strong ventral compression with structural kyphosis
  • Paravertebral hematoma
  • Weakness or numbness/tingling
  • Depending on complications and any accompanying injuries, further symptoms, potentially as severe as paralysis, are possible.
  • Neurogenic shock

Subtypes and variants

Atlas fracture

  • Definition: fracture of the atlas (first cervical vertebra)
    • Injury mode: axial force (e.g., swimming accident caused by jumping head-first into shallow water)
    • Combined fracture of the anterior and posterior arch → Jefferson fracture
  • Symptoms
    • Painful restriction of movement
    • Asymptomatic course is also possible
    • Neck ache, paravertebral hematoma with dysphagia
    • Neurologic deficits, such as Horner syndrome
  • Diagnostics
  • Treatment: immobilization for stable fractures; surgery for dislocations

Dens fracture

  • Definition: fracture of the dens axis (second cervical vertebral body)
  • Epidemiology: ∼ 10-15% of all cervical fractures
  • Etiology
    • Head or neck injury as a result of a fall or blunt trauma
    • A contributing factor is loss of bone substance as a result of a osteoporosis (mostly seen in elderly patients).
  • Symptoms
  • Specific forms: hangman's fracture
    • Definition: bilateral fracture of the axis arch
    • Etiology: trauma with hyperextension and distraction (e.g., car accident)
  • Diagnostics
    • X-ray of the spinal cord to discern an atlantoaxial dislocation CT or MRI
  • Treatment: immobilization for stable fractures, surgery for dislocations
Anderson's dens fracture classification
Type I Oblique fracture through the cranial part of the dens (rare) Stable
Type II Fracture at the base of the dens (most common) Frequently unstable
Type III Dens fracture and affected corpus axis Unstable

References:[8]

Diagnostics

  • Physical exam
    • Detailed neurologic exam (cranial nerves, motor and sensory components, coordination, and reflexes)
    • Rectal exam to assess sphincter activation
    • In trauma scenarios, a secondary survey to assess for associated injuries should be done.
  • Imaging: to assess the stability of the fracture (see “Classification” above), spinal cord lesions
    • Anterior-posterior and lateral x-ray
      • Discontinued cortex, bone fragments
      • Loss of height in the vertebral bodies
    • CT: The axial image in particular helps localize the fracture and allows for an assessment of (posterior edge) stability.
    • MRI: most sensitive tool for detecting spinal cord lesions

Do not delay urgent interventions (e.g., intubation, fluid resuscitation) in favor of imaging in patients with suspected injury to the spine who are unconscious and/or show signs of hemodynamic or respiratory compromise.

Differential diagnoses

Cervical spine distortion (whiplash injury)

  • Etiology: Often seen after car accidents due to abrupt flexion/extension movement of the neck
  • Symptoms
    • Headache, neck ache, and/or pain radiating into the back of the head, the shoulders, or the arms
    • Pain-based reduction in neck range of motion and palpable muscle tension of the shoulders and neck, as well as arm and hand paresthesia
    • General symptoms such as dizziness, nausea, fatigue, insomnia, tinnitus, and problems with concentration
  • Imaging
    • X-ray of the cervical spine
      • Cervical spine in two planes: Overlapping images at the height of CVB 7 can be avoided by pulling the arms downward or, alternatively, weighing down the hands.
      • Odontoid view in transoral anterior-posterior position with mouth open
    • CT on suspicion of changes in the spinal canal and neurologic deficits
    • Doppler ultrasound if injury to vessels in the neck is suspected
  • Treatment
    • Uncomplicated distortion
      • If necessary, short-term NSAIDs to treat muscular tension
      • Active exercise treatment
    • In case of fractures or spinal cord lesions: surgery

The differential diagnoses listed here are not exhaustive.

Treatment

General

  • Rescue from the field when there is concern for vertebral fractures
    • Place the patient on a long back board → move to stretcher once in the hospital
    • For possible injury of the cervical spine: immobilization with a rigid cervical collar
      • Duration of immobilization:
        • Until reaching final stability (e.g., surgery)
        • Or until cervical injury has been ruled out
  • Orotracheal intubation with rapid-sequence intubation is preferred for establishing an airway in an apneic patient with a cervical spine injury.

Conservative treatment

  • Indication: stable fractures
  • Procedures
    • Pain medication
    • Physical therapy
    • External bracing and orthotics to maintain spinal alignment, promote healing, and control pain through immobilization for about 8–12 weeks

Surgical treatment

  • Spondylodesis
    • Indications: unstable fractures and/or neurological symptoms
    • Approach: fusion of two or more vertebral bodies via internal fixation using plates, rods, screws, or cages
  • Minimally invasive procedures
    • Indication: stable vertebral compression fractures with progressive pain or kyphosis despite conservative treatment
    • Procedures
      • Vertebroplasty: injection of bone cement into the fractured vertebra for immediate stabilization
      • Kyphoplasty; : reexpansion of the fracture through insertion of an inflatable balloon into the vertebral body and injection of bone cement

To minimize risk of spinal cord lesions causing permanent neurological injury, treatment of unstable fractures should be initiated as soon as possible.

References:[5][9][10]

Complications

  • Spinal cord injury
    • Severe injury of the spinal cord → respiratory depression
    • Spinal contusion/concussion to spinal shock → neurological deficits
  • Injuries of the cervical spine may include a retropharyngeal hematomadysphagia
  • Vessel injury
    • Dissection or thrombotic blockage of the vertebral artery may lead to impaired vision.
  • Posttraumatic deformation of the spine: loss of height, scoliosis, or kyphosis

We list the most important complications. The selection is not exhaustive.