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Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

Radiography of the cervical spine in trauma
Thad Jackson, MD, Deborah Blades, MD*
Department of Neurosurgery, College of Medicine, University of Kentucky,
800 Rose Street, Lexington, KY 40536-0298, USA

This article illustrates the typical clinical and radiographic findings of patients with injuries to
the cervical spine and discusses basic treatment guidelines
...
The initial evaluation is both clinical (questioning about neck pain, palpating
the neck, and neurologic examination) and radiographic, if indicated
...

The initial radiographic work-up consists of anteroposterior, lateral, and open-mouth odontoid views
...
If this view remains inadequate, a computed tomography (CT)
scan through the nonvisualized vertebral bodies should be obtained
...
Early recognition of cervical spine injury and consultation of a spine specialist is imperative for a good neurologic outcome
...
AOD has been found in 19% to 35% of autopsies of fatal cervical spine injuries
...

Signs and symptoms
AOD is typically fatal [1,2]
...
Among survivors, more than 70% have an associated head injury [3]
...
Complete quadriplegia or brainstem injury typically results in death
...
Patients will frequently deteriorate when placed in cervical traction
...

Etiology/pathophysiology
AOD is caused by violent trauma (typically, motor vehicle collision or pedestrian struck
by car) and may be related to hyperextension with distraction [1,3]
...
From a mechanical view, the distal vertebral artery as well as the head is
* Corresponding author
...
uky
...
Blades)
...
All rights reserved
...
Jackson, D
...
At autopsy, none of these
patients had evidence for mechanical injury or transection of the cord [4]
...
Plain lateral radiographs are typically the first test ordered
...
The opisthion and basion are often
difficult to identify on plain films, making thin-slice CT (3-mm cuts) with sagittal reconstruction
a more accurate way of identifying AOD (see Power’s ratio in the Image hallmarks section)
...

Image hallmarks
There is typically massive retropharyngeal soft tissue swelling (Fig
...
On plain lateral radiographs, the Power’s ratio is frequently employed
...
0 in all cases of AOD
...
9 is normal, whereas ratios of 0
...
0 are
borderline, representing 7% of the normal population and no cases of AOD [2]
...
Patients are typically
reduced and placed in a halo vest
...


Fig
...
Lateral radiograph with massive soft tissue swelling
...
Jackson, D
...

Signs and symptoms
Patients will frequently have torticollis, inability to rotate their head, facial flattening (if
chronic), and upper cervical pain
...

Etiology/pathophysiology
Rotatory subluxation typically occurs in children because the facet joints are smaller and
more steeply inclined, and children have a larger head-to-body ratio, making the joint prone
to rotational damage [7]
...

Image of choice for diagnosis
Diagnosis may be made with an open-mouth odontoid view; however, thin-cut CT from the
occiput through C2 is the preferred imaging test
...
2)
...
CT scan typically shows the rotation of the atlas on the axis [6,7]
...
2
...
(B) Lateral radiograph demonstrating rotation of C1 on C2
...


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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

Fig
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Jackson, D
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Longstanding or recurrent subluxation will often be treated with open reduction and fusion (C1-2) [7]
...

Signs and symptoms
Common symptoms associated with dens fracture involve upper cervical pain
...
It is estimated that 25% to 40% of patients with this fracture die at the time of the accident
...
Approximately
20% of patients with dens fractures present with myelopathy
...

Etiology/pathophysiology
Most dens fractures are probably the result of flexion injuries secondary to violent trauma
...
In elderly and young patients, dens fractures have been reported following falls [9]
...
If the dens is not well
visualized, anteroposterior (A-P) and lateral tomograms may be helpful
...
If a CT scan is ordered, 2- to 3-mm cuts with sagittal reconstructions should be performed (when a dens fracture is suspected)
...
3), and type III fractures occur through the body of C2
...
Type II fractures have a high rate of nonunion, particularly if there
is displacement (>4–6 mm) or the patient is elderly [8]
...
If there is
significant displacement or the patient is elderly, these fractures will typically require surgical
fusion (odontoid screw or posterior C1-2 fusion) [8]
...


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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

Fig
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(A) Lateral radiograph demonstrating a type II dens fracture
...
(C) Tomogram demonstrating fracture through the base of the dens
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Fig
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Jackson, D
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Signs and symptoms
Patients very rarely have neurologic symptoms; frequently, patients complain of neck pain
...

Etiology/pathophysiology
Typically, an axial loading force to the skull causes this type of fracture [10]
...

Most fractures are also associated with tear of the transverse ligament, which allows ring widening to occur and also makes this a highly unstable injury at the C1-C2 level: tear of the transverse ligament may further injure the cord but at a lower level than the AOD
...
Most of these AOD exhibit very marked prevertebral soft tissue swelling not
seen to this degree with other cervical spine injuries
...
The Power’s ratio is only good for anterior AOD, and is negative for dislocation
if it is in a posterior or longitudinal direction
...
The difficulty with the plain radiographic methods is identifying reliably the basion and
opisthion
...
Fracture through the anterior and posterior neural arches of
C1 is seen on CT scan (Fig
...
There is typically significant retropharyngeal soft tissue swelling
...
The unaffected tubercle can be seen
on the contralateral side
...
Most of the time with AOD, there is also instability at the
C1-C2 level as well
...

Fractures with less than 7 mm of displacement are treated with a hard collar or halo vest immobilization
...


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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

175

Fig
...
CT scan demonstrating a Jefferson fracture through the anterior and posterior neural arches of C1
...

Signs and symptoms
Neck pain and pain with motion are frequently experienced
...
There is a high incidence of associated head injury (70%–80%) [2]
...
The classic scenario is
an unrestrained passenger in a motor vehicle collision in which the chin of the passenger is
forced into marked hyperextension on the dashboard or on the steering wheel
...


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Fig
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(A) Lateral radiograph demonstrating fracture through pedicles of C2
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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

177

Image hallmarks
Plain films do not demonstrate the bilateral arch fracture through the C2 pedicles well,
whereas CT clearly shows the fracture (Fig
...
Anterior subluxation of C2 on C3 is frequently
seen on the plain radiographs
...
Nevertheless, if this chip is seen, one must presume there is an associated
hangman’s fracture, until the CT scan proves otherwise
...
For type I fractures (<3 mm of displacement), the patient may be treated with a hard collar or halo vest (for unreliable patients)
for 12 weeks
...
Type III fractures
(pars fracture with bilateral facet dislocation at C2-3) typically require operative intervention
(anterior cervical fusion of C2-3) [2]
...

The teardrop fracture, which is the most common in the cervical spine, may be considered to be
a variation of the burst fracture
...

Etiology/pathophysiology
Burst fractures are secondary to an axial loading injury [13]
...
Anteroposterior views
are often helpful in differentiating from compression fractures (increased interpedicular distance
is often seen in burst fractures)
...
Magnetic resonance imaging (MRI) is helpful in identifying associated ligamentous injuries but is not necessary in most cases of burst fracture
...
6A)
...
CT
scans will often show a comminuted fracture of the vertebral body and demonstrate the associated posterior element fracture (pedicle, lamina, spinous process; Fig
...

Management
Burst fractures are typically treated with anterior body corpectomy and fusion
...


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Fig
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(A) Lateral radiograph of C6 burst fracture
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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

179

Compression/wedge fracture
Frequency/incidence
Simple compression fractures with wedge deformity of the body are uncommon in the cervical spine but more commonly seen in the thoracic and lumbar regions
...
Neurologic deficits are
rare with compression fractures (neurologic injury would imply instability and a more significant injury than a simple compression fracture)
...

Image of choice for diagnosis
Compression fractures are seen on plain lateral radiographs
...

Image hallmarks
On plain radiographs, there is loss of vertebral body height anteriorly with preservation of
the posterior vertebral body height (wedge-shaped vertebral body; Fig
...
On CT scan, there
is cortical disruption of the anterior cortical margin of the vertebral body (Fig
...

Management
Patients with compression fractures are typically treated using rigid immobilization (hard
collar) for 6 to 12 weeks
...
This instability implies ligamentous injury as well, because
the simple wedge fractures are not unstable injuries unless there has been an acute loss in height
of more than 50%
...
Bilateral and unilateral fractures are most commonly found at the C6-7 level
...
Sonntag
and Hadley [15] found that of 31 patients, 6 were neurologically intact with pain only, 7 had
root deficits only, 10 had incomplete spinal cord injuries, and 7 had complete neurologic injuries
...
In a
study of 37 patients, 31 patients had complete spinal cord injuries and 6 had incomplete spinal
cord injuries [15]
...
Jackson, D
...
7
...
(B) CT scan of fracture through anterior portion of vertebral body
...


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181

Image of choice for diagnosis
Plain lateral radiographs are adequate in the diagnosis of unilateral and bilateral facet
fracture-dislocations
...

Image hallmarks
With unilateral facet fracture-dislocation, there is subluxation of approximately 25% of the
superior vertebral body relative to the inferior vertebral body (Fig
...
Typically there is also
evidence of rotation
...
On CT, the affected facet joint appears to
be two semicircles with the curved surfaces abutting each other, thus uncovering the facet joint
itself
...

Management
For unilateral facet fractures, closed reduction using cervical traction is attempted
...
If unable to achieve closed reduction, open reduction and

Fig
...
(A) Lateral radiograph of unilateral facet and associated subluxation of C4 on C5 of approximately 25% of the width
of the vertebral body
...
(C) Lateral radiograph of bilateral locked
facets with subluxation of approximately 50% of the width of the vertebral body
...


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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

Fig
...
Jackson, D
...
8 (continued)

internal fixation using interspinous cables or lateral mass plates are typically undertaken
...


Teardrop fracture
Frequency/incidence
Teardrop fractures represent approximately 5% of cervical spine fractures [2]
...
They are rarely neurologically intact [2]
...
An
unrestrained automobile passenger with the head flexed and then driven into the dashboard
may also sustain this injury
...
This persistent retropulsion of the body is seen on plain radiographs in most
patients [17]
...
Jackson, D
...
Teardrop fractures are associated with retropulsion of
the fractured body, sagittal body fracture, and laminar fractures, which are not seen with simple
avulsion fractures [17]
...

Image hallmarks
A triangular piece of bone is typically seen at the anterior inferior edge of the fractured vertebral body (the ‘‘teardrop’’; Fig
...
Frequently, there is an associated sagittal fracture of the
vertebral body
...
The fractured vertebral body is usually displaced posteriorly relative to the vertebral body below
...
The
subjacent disc space is often narrowed
...
CT scanning may better show the sagittal vertebral body fracture, which is frequently present, and more
accurately assess the degree of spinal canal compromise (Fig
...

Management
If the ligamentous structures (including the disc) are intact and there is no spinal cord
compression, the teardrop fracture may be treated with halo immobilization for 8 to 12 weeks
followed by flexion-extension cervical-spine X rays to ensure stability
...
9
...
Note the posterior subluxation of C5 on C6
...


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Blades / Atlas Oral Maxillofacial Surg Clin N Am 10 (2002) 167–187

185

Fig
...
If there is associated posterior ligamentous injury, a combined anterior-posterior fusion may be indicated [2]
...
It is usually seen in patients performing excessive manual labor, such as grave diggers [18]
...
There is no neurologic deficit
...

Etiology/pathophysiology
Avulsion of the spinous process occurs by forces transmitted from the trapezius and other
muscles attached to the spinous process
...
As the shoveler attempts to throw the dirt off his shovel by tossing
it behind his head, the clay sticks to the shovel causing a forced hyperextension load to the neck,
which crowds the lower cervical posterior spinous process leading to fracture
...
Jackson, D
...
10
...
(B) CT of fracture through spinous process
...
Jackson, D
...

Image hallmarks
There is fracture of spinous process of C7, C6, or T1 (in decreasing frequency; Fig
...

Management
This is a stable fracture
...
Hard-collar immobilization
may be used as needed for pain control [2]
...
Traumatic atlanto-occipital dislocation
...
J Neurosurg
1986;65:863–70
...
In: Handbook of neurosurgery
...
Lakeland, FL: Greenberg Graphics; 1994
...
322–24,
580–605
...
Traumatic injuries of the occipital-cervical articulation
...
Disorders of the cervical spine
...
p
...

[4] Lee C, Woodring JH, Walsh JW
...
J Trauma 1991;31:401–7
...
Evaluation of traumatic atlanto-occipital dislocations
...

[6] Fielding JW, Hawkins RJ
...
Fixed rotatory subluxation of the atlanto-axial joint
...

[7] Sponseller PD, Herzenberg JE
...
In: Clark CR, editor
...
3rd
edition
...
p
...

[8] Apuzzo MLJ, Heiden JS, Weiss MH, et al
...
J Neurosurg 1978;48:85–91
...
Fractures of the dens
...
The cervical spine
...
Philadelphia:
Lippincott-Raven; 1998
...
415–28
...
Fractures of the first cervical vertebra
...
The cervical spine
...
Philadelphia:
Lippincott-Raven; 1998
...
409–13
...
Cervical spine trauma: the common combined conditions
...

[12] Schneider RC, Livingston KE, Cave AJE, et al
...
J Neurosurg
1965;22:141–54
...
Cervical spine burst fractures
...
The cervical spine
...

Philadelphia: Lippincott-Raven; 1998
...
465–73
...
Unrecognized spinal instability associated with seemingly ‘‘simple’’ cervical compression
fractures
...

[15] Sonntag VKH, Hadley MN
...
In: Camins MB, O’Leary PF,
editors
...
Baltimore, MD: Williams & Wilkins; 1992
...
459–64
...
Chronic neurologic sequelae of acute trauma to the spine and spinal cord
...
J Bone Joint Surg 1956;38A:985–97
...
Triangular cervical vertebral body fractures: diagnostic significance
...

[18] Hall RDM
...
J Bone Joint Surg 1940;22:63–75
...
Soft-tissue neck injuries
...
The cervical spine
...
Philadelphia:
Lippincott-Raven; 1998
...
351–5

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