eMedicine Specialties > Emergency Medicine > Trauma & Orthopedics

Fracture, Cervical Spine

Moira Davenport, MD, Attending Physician, Departments of Emergency Medicine and Orthopedic Surgery, Allegheny General Hospital

Updated: Oct 30, 2009

Introduction

Background

Approximately 5-10% of unconscious patients who present to the ED as the result of a motor vehicle accident or fall have a major injury to the cervical spine. Most cervical spine fractures occur predominantly at 2 levels. One third of injuries occur at the level of C2, and one half of injuries occur at the level of C6 or C7. Most fatal cervical spine injuries occur in upper cervical levels, either at craniocervical junction C1 or C2.

The normal anatomy of the cervical spine consists of 7 cervical vertebrae separated by intervertebral disks and joined by a complex network of ligaments. These ligaments keep individual bony elements behaving as a single unit.

View the cervical spine as 3 distinct columns: anterior, middle, and posterior. The anterior column is composed of the anterior longitudinal ligament and the anterior two thirds of the vertebral bodies, the annulus fibrosus and the intervertebral disks. The middle column is composed of the posterior longitudinal ligament and the posterior one third of the vertebral bodies, the annulus and intervertebral disks. The posterior column contains all of the bony elements formed by the pedicles, transverse processes, articulating facets, laminae, and spinous processes.

The anterior and posterior longitudinal ligaments maintain the structural integrity of the anterior and middle columns. The posterior column is held in alignment by a complex ligamentous system, including the nuchal ligament complex, capsular ligaments, and the ligamenta flava.

If one column is disrupted, other columns may provide sufficient stability to prevent spinal cord injury. If 2 columns are disrupted, the spine may move as 2 separate units, increasing the likelihood of spinal cord injury.

The atlas (C1) and the axis (C2) differ markedly from other cervical vertebrae. The atlas has no vertebral body; however, it is composed of a thick anterior arch with 2 prominent lateral masses and a thin posterior arch. The axis contains the odontoid process that represents fused remnants of the atlas body. The odontoid process is held in tight approximation to the posterior aspect of the anterior arch of C1 by the transverse ligament, which stabilizes the atlantoaxial joint.

Apical, alar, and transverse ligaments provide further stabilization by allowing spinal column rotation; this prevents posterior displacement of the dens in relation to the atlas.

For more information, see Medscape's Fracture Resource Center and Spinal Disorders Resource Center.

Pathophysiology

Cervical spine injuries are best classified according to several mechanisms of injury. These include flexion, flexion-rotation, extension, extension-rotation, vertical compression, lateral flexion, and imprecisely understood mechanisms that may result in odontoid fractures and atlanto-occipital dislocation.

Flexion injury

Common injuries associated with a flexion mechanism include the following:

• Simple wedge compression fracture without posterior disruption
• Flexion teardrop fracture
• Anterior subluxation
• Bilateral facet dislocation
• Clay shoveler fracture
• Anterior atlantoaxial dislocation

Simple wedge fracture

With a pure flexion injury, a longitudinal pull is exerted on the nuchal ligament complex that, because of its strength, usually remains intact. The anterior vertebral body bears most of the force, sustaining simple wedge compression anteriorly without any posterior disruption.

Radiographically the anterior border of the vertebral body has diminished height and increased concavity along with increased density due to bony impaction (see Image 2A). The prevertebral soft tissues are swollen.

(A) Simple wedge fracture with a flexion mechanism of injury is stable. (B) Flexion teardrop fracture with a flexion mechanism is unstable.

Flexion teardrop fracture

A flexion teardrop fracture occurs when flexion of the spine, along with vertical axial compression, causes a fracture of the anteroinferior aspect of the vertebral body. This fragment is displaced anteriorly and resembles a teardrop (see Image 2B). For this fragment to be produced significant posterior ligamentous disruption must occur. Since the fragment displaces anteriorly, a significant degree of anterior ligamentous disruption exists.

This injury involves disruption of all 3 columns, making this an extremely unstable fracture that frequently is associated with spinal cord injury. Initial management is application of traction with cervical tongs.

Anterior subluxation

Anterior subluxation in the cervical spine occurs when posterior ligamentous complexes (nuchal ligament, capsular ligaments, ligamenta flava, posterior longitudinal ligament) rupture. The anterior longitudinal ligament remains intact. No associated bony injury is seen.

Radiographically, the lateral view shows widening of interspinous processes, and anterior and posterior contour lines are disrupted in flexion views (see Image 3). Since the anterior columns remain intact, this fracture is considered mechanically stable by definition.

Anterior subluxation with a flexion mechanism is stable in extension but potentially unstable in flexion.

Bilateral facet dislocation

Bilateral facet dislocation is an extreme form of anterior subluxation that occurs when a significant degree of flexion and anterior subluxation causes ligamentous disruption to extend anteriorly, which causes significant anterior displacement of the spine at the level of injury. This injury involves the annulus fibrosus, anterior longitudinal ligament and posterior ligamentous complex. At the level of injury, ie, the upper vertebrae, inferior articulating facets pass superior and anterior to the superior articulating facets of the lower involved vertebrae because of extreme flexion of the spine.

Radiographically, this is seen as a displacement of more than half of the anteroposterior diameter of the vertebral body in the lateral view (see Image 4).

Bilateral facet dislocation with a flexion mechanism is extremely unstable and can have an associated disk herniation that impinges on the spinal cord during reduction.

Clay shoveler fracture

Abrupt flexion of the neck, combined with a heavy upper body and lower neck muscular contraction, results in an oblique fracture of the base of the spinous process, which is avulsed by the intact and powerful supraspinous ligament. Fracture also occurs with direct blows to the spinous process or with trauma to the occiput that causes forced flexion of the neck.

Injury commonly is observed in a lateral view, since the avulsed fragment is readily evident (see Image 5A). Injury commonly occurs in lower cervical vertebrae; therefore, visualization of the C7-T1 junction in the lateral view is imperative. Injury also may be seen in the anteroposterior view as a vertically split appearance of the spinous process in the lower vertebrae (see Image 5B).

Clay shoveler fracture. (A) Lateral view of this fracture caused by a flexion mechanism shows that it is stable and represents an avulsion fracture of the base of the spinous process near the supraspinous ligament. (B) Anteroposterior view shows the vertically split appearance of the spinous process.

Common injuries associated with a flexion-rotation mechanism include unilateral facet dislocation and rotary atlantoaxial dislocation.

Unilateral facet dislocation

Unilateral facet dislocation occurs when flexion, along with rotation, forces one inferior articular facet of an upper vertebra to pass superior and anterior to the superior articular facet of a lower vertebra, coming to rest in the intervertebral foramen (see Image 6A). Although the posterior ligament is disrupted, vertebrae are locked in place, making this injury stable.

Radiographically, the lateral view shows an anterior displacement of the spine at the involved level of less than one half the diameter of the vertebral body. This is in contrast to the greater displacement seen with a bilateral facet dislocation, as discussed above. The anteroposterior view is useful in diagnosis of unilateral dislocation because it shows a disruption in the line connecting the spinous processes at the level of the dislocation (see Image 6B). The oblique view is also useful because it shows a disruption of the typical shingles appearance at the level of the involved vertebra (see Image 6C). The dislocated superior articulating facet of the lower vertebra is seen projecting within the neural foramina.

Unilateral facet dislocation. (A) Lateral view of this fracture caused by a flexion-rotation mechanism shows that it is stable. Anterior displacement of spine is less than one half of the diameter of a vertebral body. (B) Anteroposterior view shows disruption of a line connecting spinous processes at the level of the dislocation. (C) Oblique view shows that the expected tiling of the laminae is disrupted, and the dislocated superior articulating facet of the lower vertebra is seen projecting within the neural foramina.

Rotary atlantoaxial dislocation

This injury is a specific type of unilateral facet dislocation.

Radiographically, the odontoid view shows asymmetry of the lateral masses of C1 with respect to the dens along with unilateral magnification of a lateral mass of C1 (wink sign). However, since the atlantoaxial joint permits flexion, extension, rotation, and lateral bending, radiographic asymmetry is produced when the head is tilted laterally or rotated or if a slightly oblique odontoid view is obtained despite perfect head positioning. To confirm true dislocation, basilar skull structures (jugular foramina) should appear symmetric in the presence of the findings described above.

This injury is considered unstable because of its location.

Common injuries associated with an extension mechanism include hangman fracture, extension teardrop fracture, fracture of the posterior arch of C1 (posterior neural arch fracture of C1) and posterior atlantoaxial dislocation.

Hangman fracture (traumatic spondylolisthesis of C2)

The name of this injury is derived from the typical fracture that occurs after hangings. Presently, it commonly is caused by motor vehicle collisions and entails bilateral fractures through the pedicles of C2 due to hyperextension.

Radiographically, a fracture line should be evident extending through the pedicles of C2 along with obvious disruption of the spinolaminar contour line (see Image 7).

Hangman fracture caused by an extension mechanism is unstable. Fracture line is evident in the lateral projection extending through pedicles of C2, along with disruption of the spinolaminar line. Sometimes, this fracture is associated with unilateral or bilateral facet dislocation, which makes it highly unstable.

Extension teardrop fracture

As with flexion teardrop fracture, extension teardrop fracture also manifests with a displaced anteroinferior bony fragment. This fracture occurs when the anterior longitudinal ligament pulls fragment away from the inferior aspect of the vertebra because of sudden hyperextension. The fragment is a true avulsion, in contrast to the flexion teardrop fracture in which the fragment is produced by compression of the anterior vertebral aspect due to hyperflexion.

The fracture is common after diving accidents and tends to occur at lower cervical levels. It also may be associated with the central cord syndrome due to buckling of the ligamenta flava into spinal canal during the hyperextension phase of injury.

This injury is stable in flexion but highly unstable in extension. Initial management is avoidance of iatrogenic extension and cervical traction with tongs.

Fracture of the posterior arch of C1 fracture (posterior neural arch fracture)

This fracture occurs when the head is hyperextended and the posterior neural arch of C1 is compressed between the occiput and the strong, prominent spinous process of C2, causing the weak posterior arch of C1 to fracture (see Image 8A).

(A) Fracture of the posterior arch of C1 fracture caused by an extension mechanism is stable. Lateral projection shows a fracture line through the posterior neural arch without widening predental space. An odontoid view must be obtained to differentiate this benign fracture from a Jefferson fracture. (B) Jefferson fracture caused by a vertical (axial) compression mechanism is unstable. This fracture of all aspects of the C1 ring is associated with possible disruption of the transverse ligament of the atlas. Lateral projection may show a widened predental space and a fracture through the posterior arch of C1. Odontoid view shows displacement of the lateral masses of C1, allowing distinction of this fracture from a simple fracture of the posterior neural arch of C1.

The transverse ligament and the anterior arch of C1 are not involved, making this fracture stable. Initial management involves the differentiation of this benign fracture from a Jefferson fracture. Once this is accomplished, only use of a cervical orthosis is required.

Common injuries associated with a vertical compression mechanism include Jefferson fracture (burst fracture of the ring of C1), burst fracture (dispersion, axial loading), atlas fracture, and isolated fracture of the lateral mass of C1 (pillar fracture).

Jefferson fracture (burst fracture of the ring of C1)

This fracture is caused by a compressive downward force that is transmitted evenly through the occipital condyles to the superior articular surfaces of the lateral masses of C1. The process displaces the masses laterally and causes fractures of the anterior and posterior arches, along with possible disruption of the transverse ligament. Quadruple fracture of all 4 aspects of the C1 ring occurs.

Radiographically the fracture is characterized by bilateral lateral displacement of the articular masses of C1. The odontoid view shows unilateral or bilateral displacement of the lateral masses of C1 with respect to the articular pillars of C2; this finding differentiates it from a simple fracture of the posterior neural arch of C1 (see Image 8B). The lateral projection usually reveals a striking amount of prevertebral soft tissue edema.

When displacement of the lateral masses is more than 6.9 mm complete disruption of the transverse ligament has occurred and immediate referral for cervical traction is warranted. If displacement is less than 6.9 mm, the transverse ligament is still competent and neurologic injury is unlikely.

Burst fracture of the vertebral body

When downward compressive force is transmitted to lower levels in the cervical spine, the body of the cervical vertebra can shatter outward, causing a burst fracture. This fracture involves disruption of the anterior and middle columns, with a variable degree of posterior protrusion of the latter.

Radiographically, this fracture is evidenced by a vertical fracture line in the frontal projection and by comminution and protrusion of the vertebral body anteriorly and posteriorly with respect to the contiguous vertebrae in the lateral view (see Image 9). Posterior protrusion of the middle column may extend into the spinal canal and can be associated with anterior cord syndrome. Burst fractures always require an axial CT scan or MRI to document amount of middle column retropulsion.

Burst fracture of vertebral body caused by a vertical (axial) compression mechanism is stable mechanically and involves disruption of the anterior and middle columns, with variable degree of protrusion of the latter. This middle column posterior protrusion may extend into the spinal canal and be associated with an anterior cord syndrome.

Common injuries associated with multiple or complex mechanisms include odontoid fracture, fracture of the transverse process of C2 (lateral flexion), atlanto-occipital dislocation (flexion or extension with a shearing component), and occipital condyle fracture (vertical compression with lateral bending).

Upper cervical spine (occiput to C2) injuries

Injuries at the upper cervical level are considered unstable because of their location. Nevertheless, since the diameter of the spinal canal is greatest at the level of C2, spinal cord injury from compression is the exception rather than the rule. Incompletely understood mechanisms or a combination of mechanisms usually produce injuries encountered at this level.

Common injuries include fracture of the atlas, atlantoaxial subluxation, odontoid fracture, and hangman fracture (see Extension injury above). Less common injuries include occipital condyle fracture, atlanto-occipital dislocation, atlantoaxial rotary subluxation (see Flexion-rotation injury above), and C2 lateral mass fracture.

Atlas (C1) fractures

Four types of atlas fractures (I, II, III, IV) result from impaction of the occipital condyles on the atlas, causing single or multiple fractures around the ring.

The first 2 types of atlas fracture are stable and include isolated fractures of the anterior and posterior arch of C1 (posterior arch fracture is described under Extension injury). Anterior arch fractures usually are avulsion fractures from the anterior portion of the ring and have a low morbidity rate and little clinical significance. The third type of atlas fracture is a fracture through the lateral mass of C1. Radiographically, asymmetric displacement of the mass from the rest of the vertebra is seen in the odontoid view. This fracture also has a low morbidity rate and little clinical significance.

The fourth type of atlas fracture is the burst fracture of the ring of C1 and also is known as a Jefferson fracture (discussed under Vertical (axial) compression injury above). This is the most significant type of atlas fracture from a clinical standpoint because it is associated with neurologic impairment.

Initial management of types I, II, and III atlas fractures consists of placement of a cervical orthosis. Type IV fracture, or Jefferson fracture, is managed with cervical traction.

Atlantoaxial subluxation

When flexion occurs without a lateral or rotatory component at the upper cervical level, it can cause an anterior dislocation at the atlantoaxial joint if the transverse ligament is disrupted. Because this joint is near the skull, shearing forces also play a part in the mechanism causing this injury, as the skull grinds the C1-C2 complex in flexion. Since the transverse ligament is the main stabilizing force of the atlantoaxial joint, this injury is unstable. Neurologic injury may occur from cord compression between the odontoid and posterior arch of C1.

Radiographically, this injury is suspected if the predental space is more than 3.5 mm (5 mm in children); axial CT is used to confirm the diagnosis. These injuries may require fusion of C1 and C2 for definitive management.

Atlanto-occipital dislocation

When severe flexion or extension exists at the upper cervical level, atlanto-occipital dislocation may occur. Atlanto-occipital dislocation involves complete disruption of all ligamentous relationships between the occiput and the atlas. Death usually occurs immediately from stretching of the brainstem, which causes respiratory arrest.

Radiographically, disassociation between the base of the occiput and the arch of C1 is seen. Cervical traction is absolutely contraindicated, since further stretching of the brainstem can occur.

Odontoid process fractures

The 3 types of odontoid process fractures are classified based on the anatomic level at which the fracture occurs (see Image 1).

Odontoid fractures. (A) Type I odontoid fracture represents an avulsion of the tip of the dens at the insertion site of the alar ligament. Although mechanically stable, it is associated with life-threatening atlanto-occipital dislocation. (B) Type II odontoid fracture is a fracture at the base of the dens. This is the most common type of odontoid fracture. (C) With type III odontoid fracture, the fracture line extends into the body of the axis.

• Type I odontoid fracture is an avulsion of the tip of the dens at the insertion site of the alar ligament. Although a type I fracture is mechanically stable, it often is seen in association with atlanto-occipital dislocation and must be ruled out because of this potentially life-threatening complication.
• Type II fractures occur at the base of the dens and are the most common odontoid fractures. This type is associated with a high prevalence of nonunion due to the limited vascular supply and small area of cancellous bone.
• Type III odontoid fracture occurs when the fracture line extends into the body of the axis. Nonunion is not a major problem with these injuries because of a good blood supply and the greater amount of cancellous bone.

With types II and III fractures, the fractured segment may be displaced anteriorly, laterally, or posteriorly. Since posterior displacement of segment is more common, the prevalence of spinal cord injury is as high as 10% with these fractures.

Initial management of a type I dens fracture is use of a cervical orthosis. Manage types II and III fractures by applying traction with cervical tongs.

Occipital condyle fracture

Occipital condyle fractures are caused by a combination of vertical compression and lateral bending. Avulsion of the condylar process or a comminuted compression fracture may occur secondary to this mechanism. These fractures are associated with significant head trauma and usually are accompanied by cranial nerve deficits.

Radiographically, they are difficult to delineate, and axial CT may be required to identify them.

These mechanically stable injuries require only orthotic immobilization for management, and most heal uneventfully. These fractures are significant because of the injuries that usually accompany them.

Column disruption may lead to mechanical instability of the cervical spine. The degree of instability depends on several factors that may translate into neurologic disability, secondary to spinal cord compression. A full spectrum of cervical injuries with varying degrees of clinical importance, from the clinically insignificant to the potentially disastrous, exists. As many as 39% of cervical fractures have some degree of associated neurologic deficit.

The risk of neurologic injury, secondary to spinal injury, increases with degenerative changes related to aging, arthritic conditions (rheumatoid arthritis, ankylosing spondylitis), spinal stenosis, spina bifida, and os odontoideum, as well as the specific mechanism and location of the injury.

Trafton has ranked specific cervical injuries based on their degree of mechanical instability.¹ The list below ranks cervical spine injuries in order of instability (most to least unstable):

• Rupture of the transverse ligament of the atlas
• Fracture of the dens (odontoid fracture)
• Burst fracture with posterior ligamentous disruption (flexion teardrop fracture)
• Bilateral facet dislocation
• Burst fracture without posterior ligamentous disruption
• Hyperextension fracture dislocation
• Hangman fracture
• Extension teardrop (stable in flexion)
• Jefferson fracture (burst fracture of the ring of C1)
• Unilateral facet dislocation
• Anterior subluxation
• Simple wedge compression fracture without posterior disruption
• Pillar fracture
• Fracture of the posterior arch of C1
• Spinous process fracture (clay shoveler fracture)

Frequency

United States

Cervical spine injuries cause an estimated 6000 deaths and 5000 new cases of quadriplegia each year.

Sex

Male-to-female ratio is 4:1.

Age

• Most patients with a cervical spine injury are in their prime and leading an active lifestyle prior to injury.
• Approximately 80% of patients are aged 18-25 years.

Clinical

History

Common presentations of cervical spine fracture include the following:

• Posterior neck pain on palpation of spinous processes
• Limited range of motion associated with pain
• Weakness, numbness, or paresthesias along affected nerve roots

Physical

Clinical evaluation of the cervical spine in a patient with blunt trauma is unreliable. In a study of surgical residents' ability to predict cervical injuries on the basis of clinical examination alone, sensitivity and specificity were 46% and 94%, respectively. Because of these limitations and potential for catastrophic morbidity if injury is missed, most patients with complex blunt trauma seen in the ED undergo radiographic evaluation before clearance, with some exceptions.

Common findings on physical examination in cervical spine injury include the following:

• Spinal shock
  • Flaccidity
  • Areflexia
  • Loss of anal sphincter tone
  • Fecal incontinence
  • Priapism
  • Loss of bulbocavernosus reflex
• Neurogenic shock
  • Hypotension
  • Paradoxical bradycardia
  • Flushed, dry, and warm peripheral skin
• Autonomic dysfunction
  • Ileus
  • Urinary retention
  • Poikilothermia

Causes

Motor vehicle accidents and falls account for 50% and 20% of cervical spine injuries, respectively. Sports-related activities account for 15%. The remaining injuries are attributed to interpersonal violence.

The following athletic activities have the highest incidence of associated cervical spine injuries. Participants in these events should be considered at high risk.

• Diving
• Equestrian activities
• Football
• Gymnastics
• Skiing
• Hang gliding

Differential Diagnoses

Workup

Imaging Studies

• Radiographic evaluation
  • Patients who exhibit neurologic deficits consistent with a cord lesion
  • Patients with an altered sensorium from head injury or intoxication
  • Patients who complain about neck pain or tenderness
  • Patients who do not complain about neck pain or tenderness but have significant distracting injuries
• Recent literature has examined the need for c-spine imaging in patients who are low risk for unstable fracture or ligamentous injury. Two clinical decision-making criteria, the Canadian C-Spine Rules (CCR) and the National Emergency X-Radiography Utilization Group (NEXUS) criteria allow clinicians to "clear" low-risk patients of c-spine injury, obviating the need for radiography.
  • To be clinically cleared using the CCR, a patient must be alert (GCS 15), not intoxicated, and not have a distracting injury (eg, long bone fracture, large laceration). The patient can be clinically cleared providing the following:
    • The patient is not high risk (age >65 y or dangerous mechanism or paresthesias in extremities).
    • A low risk factor that allows safe assessment of range of motion exists. This includes simple rear end motor vehicle collision, seated position in the ED, ambulation at any time posttrauma, delayed onset of neck pain, and the absence of midline cervical spine tenderness.
    • The patient is able to actively rotate their neck 45 degrees left and right.
  • The NEXUS criteria state that a patient with suspected c-spine injury can be cleared providing the following:
    • No posterior midline cervical spine tenderness is present.
    • No evidence of intoxication is present.
    • The patient has a normal level of alertness.
    • No focal neurologic deficit is present.
    • The patient does not have a painful distracting injury.
  • Both studies have been prospectively validated as being sufficiently sensitive to rule out clinically significant c-spine pathology. The CCR were shown to be more sensitive than the NEXUS criteria (99.4% sensitive vs 90.7%), and the rates of radiography were lower with the CCR (55.9% vs 66.6%).² Debate still exists as to which criteria are more useful and easier to apply.
• A standard trauma series is composed of 5 views: cross-table lateral, swimmer's, oblique, odontoid, and anteroposterior.
• Cross-table lateral view
  • Approximately 85-90% of cervical spine injuries are evident in lateral view, making it the most useful view from a clinical standpoint.
  • A technically acceptable lateral view shows all 7 vertebral bodies and the cervicothoracic junction. Approach analysis of this view methodically to avoid missing significant pathology.
  • Check alignment of cervical spine by following 3 imaginary contour lines.

(A) Normal lateral projection shows the relationships of anterior, posterior, and spinolaminar lines and prevertebral spaces. (B) Normal oblique projection shows the normal appearance of the laminae as shingles on a roof forming a regular elliptical curve with equal interlaminar spaces.

1. The first line connects the anterior margins of all the vertebrae and is referred to as the anterior contour line (see Image 10A).
2. The second line should connect the posterior aspect of all vertebrae in a similar way and is referred to as the posterior contour line.
3. The third line should connect the bases of the spinous processes and is referred to as the spinolaminar contour line.
• Each of these lines should form a smooth lordotic curve. Suspect bony or ligamentous injury if disruption is seen in the contour lines.
• An exception occurs in young children who, because of immature muscular development, may have a benign pseudosubluxation in the upper cervical spine. An imaginary straight line should connect the points bisecting the base of the spinous processes of C1, C2, and C3. In pseudosubluxation, these imaginary points should not be displaced more than 2 mm in front of or behind the straight line.
• Check individual vertebrae thoroughly for obvious fracture or changes in bone density. Areas of decreased bone density are seen in patients with osteoporosis, osteomalacia, or osteolytic lesions and may represent weak areas predisposed to injury. Areas of increased bony density may be seen with osteoblastic lesions or may represent compression fractures of an acute nature.
• Look for soft tissue changes in predental and prevertebral spaces. The predental space, also known as the atlantodental interval, is the distance between the anterior aspect of the odontoid and the posterior aspect of the anterior arch of C1 (see Image 10A). This space should be no more than 3 mm in an adult and 5 mm in a child. Suspect transverse ligament disruption if these limits are exceeded.
• Prevertebral space extends between the anterior border of the vertebra to the posterior wall of the pharynx in the upper vertebral level (C2-C4) or to the trachea in the lower vertebral level (C6).
• At the level of C2, prevertebral space should not exceed 7 mm.
• At the level of C3 and C4, it should not exceed 5 mm, or it should be less than half the width of the involved vertebrae.
• At the level of C6, prevertebral space is widened by the presence of the esophagus and cricopharyngeal muscle. At this level, the space should be no more than 22 mm in adults or 14 mm in children younger than 15 years.
• Children younger than 24 months may exhibit a physiologic widening of the prevertebral space during expiration; therefore, obtain images in small children during inspiration to assess prevertebral space adequately.
• If the prevertebral space is widened at any level, a hematoma secondary to a fracture is the most likely diagnosis.
• Check for fanning of the spinous processes. This is evident as an exaggerated widening of the space between 2 spinous process tips and suggests posterior ligamentous disruption.
• Check for an abrupt change in angulation of greater than 11 degrees at a single interspace. This also suggests bony injury with possible ligamentous involvement.
• Swimmer's view
  • Occasionally, it is impossible to fully visualize all 7 cervical vertebrae and, more importantly, the cervicothoracic junction in a true lateral image.
  • Failure to fully visualize these areas has resulted in patient morbidity and successful malpractice litigation against emergency physicians.
  • A swimmer's or transaxillary view adequately exposes these areas for scrutiny.
• Oblique view
  • This view also is considered a laminar view because most pathologic conditions assessed on it manifest with some disruption in the normal overlapping appearance of the vertebral laminae.
  • The normal structural appearance of the laminae is described as shingles on a roof, forming a regular elliptical curve with equal interlaminar spaces (see Image 10B).
  • If interlaminar space between 2 continuous laminae is increased, suspect subluxation of the involved vertebrae.
  • Similarly, if the expected tiling of shingles is disrupted, suspect a unilateral facet dislocation.
  • A posterior laminar fracture should be evident as disruption of the body of a single shingle.
• Odontoid view
  • This view is used to evaluate an area that is difficult to visualize in the cross-table lateral view because of shadow superimposition.
  • The most important structural relationship to evaluate in this view is alignment of the lateral masses of C1 with respect to the odontoid process.
  • Masses should be bilaterally symmetric with the dens and odontoid process and must be checked for fractures or lateral displacement.
  • Assess symmetry of the interspace between C1 and C2.
• Anteroposterior view
  • This is the least useful view from a clinical standpoint.
  • A straight line should connect the spinous processes bisecting the cervical spine. If this is not seen, consider a rotation injury (ie, unilateral facet dislocation). Also consider a clay shoveler fracture if a spinous process appears vertically split.

Other Tests

• The advent of readily available multidetector computed tomography has supplanted the use of plain radiography at many centers. Recent literature supports CT as more sensitive with lower rates of missed primary and secondary injury. One series found 36% of patients with one injury on plain radiography had a second injury seen on CT only. Of these patients, 27% had a noncontiguous, anatomically distinct second injury. The same views generated by plain radiography (AP, lateral, open mouth) are generated via CT. These results are cause to reconsider guidelines for the implementation of CT as a primary diagnostic test. If plain radiograph findings are negative but clinical suspicion for fracture is high, films should be followed by CT.
• The American College of Orthopaedic Surgeons now recommends routine cervical spine screening via CT scan instead of plain radiography. Low-dose multidetector CT scanning has been found to be as sensitive and specific as standard dose multidetector CT scans.³
• Soft tissue injury (ie, unstable ligamentous injury) has traditionally been evaluated by flexion-extension views. MR is less dangerous and more sensitive for soft tissue injury than radiography. Limited availability makes familiarity with flexion-extension views essential.
• A recent association between cervical spine fractures and thoracolumbar spine fractures has been identified in victims of motor vehicle collisions (MVC). Based on this finding, it is now recommended that any MVC patient found to have a cervical spine fracture should undergo complete spine imaging.⁴  

Treatment

Prehospital Care

When a cervical spine injury is suspected, minimize neck movement during transport to the treating facility. Ideally, transport the patient on a backboard with a semirigid collar, with the neck stabilized on the sides of the head with sand bags or foam blocks taped from side to side (of the board), across the forehead.

Emergency Department Care

• If spinal malalignment is identified, place the patient in skeletal traction with tongs as soon as possible (with very few exceptions), even if no evidence of neurologic deficit exists.
• The specific injury involved and capabilities of the consulting staff guide further management.
• Place tongs 1 finger width above the ear lobes in alignment with the external auditory canal.
• The consultant applies the tongs for traction under close neurologic and radiograph surveillance.

Consultations

• An orthopedic surgeon or neurosurgeon, depending on local availability, custom, or referral system, should be available for immediate referral.
• If the treating physician notes spinal cord injury, consult a neurosurgeon.

Medication

Administer steroids to any patient with blunt cervical spine injury and associated neurologic symptoms of less than 8 hours in onset.

Corticosteroids

Agents have anti-inflammatory properties and cause profound, varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

Methylprednisolone (Solu-Medrol, Depo-Medrol)

Decrease inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing increased capillary permeability.

Dosing

Adult

30 mg/kg IV q30min; followed by continuous IV drip 5.4 mg/kg q1h for 1 d

Pediatric

Administer as in adults

Interactions

Coadministration with digoxin, may increase digitalis toxicity secondary to hypokalemia; estrogens may increase levels of methylprednisolone; phenobarbital, phenytoin, and rifampin may decrease levels of methylprednisolone (adjust dose); monitor patients for hypokalemia when they are taking medication concurrently with diuretics

Contraindications

Documented hypersensitivity; viral, fungal, or tubercular skin infections

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Hyperglycemia, edema, osteonecrosis, peptic ulcer disease, hypokalemia, osteoporosis, euphoria, psychosis, growth suppression, myopathy, and infections are possible complications of glucocorticoid use

Follow-up

Complications

• Spinal shock
  • Severe spinal cord injury may cause a concussive injury of the spinal cord termed spinal shock syndrome.
  • Spinal shock manifests as distal areflexia of a transient nature that may last from a few hours to weeks. Initially, the patient experiences a flaccid quadriplegia along with areflexia. Segmental reflexes start to return usually within 24 hours as spinal shock starts to resolve. At that point, flaccid quadriplegia changes to spastic paralysis.
  • Eventually, total resolution can be expected.
• Neurogenic shock
  • Neurogenic shock is spinal shock that causes vasomotor instability because of loss of sympathetic tone.
  • Patients with neurogenic shock are hypotensive but have paradoxical bradycardia.
  • Flushed, dry, and warm peripheral skin, (in contrast to findings with hypovolemic or cardiogenic shock) may be present. Other signs of autonomic dysfunction include ileus, urinary retention, and poikilothermia.
  • Loss of anal sphincter tone with fecal incontinence and priapism suggest spinal shock. Return of bulbocavernosus reflex heralds resolution of spinal shock.
• Complete and incomplete cord syndromes
  • Besides spinal shock, complete and incomplete spinal cord syndromes may occur.
  • Spinal shock mimics a complete spinal cord lesion. Emergency physicians should wait until spinal shock resolves to make an accurate estimate of the patient's prognosis.
  • Incomplete cord syndromes are described and include anterior spinal cord syndrome, central spinal cord syndrome, Brown-Séquard syndrome, and less frequent, cord syndromes at high cervical levels (ie, Horner syndrome, posteroinferior cerebellar artery syndrome).
  • The prognosis of a patient with a complete lesion, after spinal shock subsides, is permanent paraplegia.
  • Patients with an incomplete lesion (partial motor or sensory function) can expect to regain some degree of function.
• Anterior spinal cord syndrome
  • Anterior spinal cord syndrome involves complete motor paralysis and loss of temperature and pain perception distal to the lesion. Since posterior columns are spared, light touch, vibration, and proprioceptive input are preserved.
  • This syndrome is caused by compression of the anterior spinal artery, which results in anterior cord ischemia or direct compression of the anterior cord. It is associated with burst fractures of the spinal column with fragment retropulsion caused by axial compression.
• Central spinal cord syndrome
  • This syndrome is caused by damage to the corticospinal tract.
  • It is characterized by weakness, greater in the upper extremities than the lower extremities and more pronounced in the distal aspect of extremity.
  • The syndrome usually is associated with a hyperextension injury in patients with spondylosis or congenital stenosis of the cervical canal.
  • Extension of the cervical spine, causing buckling of the ligamentum flavum into the spinal cord, is believed to cause central spinal cord syndrome.
• Brown-Séquard syndrome
  • This syndrome involves injury to only 1 side of spinal cord.
  • It causes paralysis, loss of vibration sensation, and loss of proprioceptive input ipsilaterally, with contralateral loss of pain and temperature perception because of involvement of posterior columns and spinothalamic tracts on the same side.
  • It is associated with hemisection of the spinal cord from penetrating trauma; however, it also can be caused by a lateral mass fracture of a cervical vertebra.
• High cervical spinal cord syndromes
  • These syndromes are associated with damage to the spinal tract of the trigeminal nerve in the high cervical region.
  • A characteristic onion-skin pattern of anesthesia in the face may occur.
• Horner syndrome
  • This syndrome manifests as ptosis, miosis, and anhydrosis.
  • It results from damage to the cervical sympathetic chain.
• Posteroinferior cerebellar artery syndrome
  • A diverse constellation of symptoms, including dysphagia, dysphonia, hiccups, vertigo, vomiting, or cerebellar ataxia, may occur.
  • Any of the high cervical cord syndromes may result from direct injury to the upper cervical level and/or cervicomedullary junction.
  • Vertebral artery occlusion from dislocation or hyperextension of the cervical column also can produce them.
• Craniofacial injuries
  • An association between significant craniofacial injuries and cervical spine fractures seems intuitively logical, yet several retrospective series do not support this assumption.
  • A retrospective review of 2555 patients with significant facial injuries found that only 1.3% had concomitant cervical spine injury.⁵ In a smaller series, 1272 patients with significant craniocerebral injury had only a 1.8% prevalence of cervical injuries.⁶ A review of 1050 patients admitted with facial fractures found only a 4% prevalence of an associated cervical injury, even though the prevalence of associated head injuries was 85%.⁷ These and other series indicate that closed head injuries and facial fractures may not significantly increase the risk of concomitant cervical spine injury.
  • A larger retrospective study suggests that there is an increased risk (4.5% vs 1.1%) of cervical spine injury with craniocerebral (but not with facial) injuries.⁸
  • Regardless of the results, none of these retrospective studies suggests decreasing standard care, such as ordering x-rays to find cervical spine injuries in trauma patients.

Patient Education

• For excellent patient education resources, visit eMedicine's Back, Ribs, Neck, and Head Center and Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education article Vertebral Compression Fracture.

Miscellaneous

Medicolegal Pitfalls

• Failure to fully visualize these areas has resulted in patient morbidity and successful malpractice litigation against emergency physicians.

Special Concerns

• Pediatric considerations
  • Structural differences between pediatric and adult cervical spines alter injury patterns and cause distinct pathology in young children.
  • The more elastic intervertebral ligaments and more horizontally aligned facet joints in young children predispose them to subluxation of the cervical spine without bony injury.
  • Immature neck muscles and a proportionally large head further compound this effect, making pediatric cervical spines act like a fulcrum and increasing the chance of injury.
  • This fulcrum starts in the upper cervical levels and changes progressively to lower levels as the pediatric cervical spine matures, until it reaches adult levels at C5 and C6. Most injuries occur at the C1-C3 levels in children younger than 8 years.
• Spinal cord injury without radiographic abnormality
  • This injury is found primarily in patients younger than 8 years and accounts for 25-50% of all pediatric cervical spine injuries.
  • It results from trauma to the spinal cord because of displacement of vertebral elements that reduce spontaneously, leaving no radiographic evidence of bony damage.
  • Patients may describe transient paresthesias, weakness or burning, or lightning sensations progressing down the affected segments.
  • This injury predisposes patients to paraplegia and neurogenic shock.

Multimedia

Media file 1: Odontoid fractures. (A) Type I odontoid fracture represents an avulsion of the tip of the dens at the insertion site of the alar ligament. Although mechanically stable, it is associated with life-threatening atlanto-occipital dislocation. (B) Type II odontoid fracture is a fracture at the base of the dens. This is the most common type of odontoid fracture. (C) With type III odontoid fracture, the fracture line extends into the body of the axis.

Media file 2: (A) Simple wedge fracture with a flexion mechanism of injury is stable. (B) Flexion teardrop fracture with a flexion mechanism is unstable.

Media file 3: Anterior subluxation with a flexion mechanism is stable in extension but potentially unstable in flexion.

Media file 4: Bilateral facet dislocation with a flexion mechanism is extremely unstable and can have an associated disk herniation that impinges on the spinal cord during reduction.

Media file 5: Clay shoveler fracture. (A) Lateral view of this fracture caused by a flexion mechanism shows that it is stable and represents an avulsion fracture of the base of the spinous process near the supraspinous ligament. (B) Anteroposterior view shows the vertically split appearance of the spinous process.

Media file 6: Unilateral facet dislocation. (A) Lateral view of this fracture caused by a flexion-rotation mechanism shows that it is stable. Anterior displacement of spine is less than one half of the diameter of a vertebral body. (B) Anteroposterior view shows disruption of a line connecting spinous processes at the level of the dislocation. (C) Oblique view shows that the expected tiling of the laminae is disrupted, and the dislocated superior articulating facet of the lower vertebra is seen projecting within the neural foramina.

Media file 7: Hangman fracture caused by an extension mechanism is unstable. Fracture line is evident in the lateral projection extending through pedicles of C2, along with disruption of the spinolaminar line. Sometimes, this fracture is associated with unilateral or bilateral facet dislocation, which makes it highly unstable.

Media file 8: (A) Fracture of the posterior arch of C1 fracture caused by an extension mechanism is stable. Lateral projection shows a fracture line through the posterior neural arch without widening predental space. An odontoid view must be obtained to differentiate this benign fracture from a Jefferson fracture. (B) Jefferson fracture caused by a vertical (axial) compression mechanism is unstable. This fracture of all aspects of the C1 ring is associated with possible disruption of the transverse ligament of the atlas. Lateral projection may show a widened predental space and a fracture through the posterior arch of C1. Odontoid view shows displacement of the lateral masses of C1, allowing distinction of this fracture from a simple fracture of the posterior neural arch of C1.

Media file 9: Burst fracture of vertebral body caused by a vertical (axial) compression mechanism is stable mechanically and involves disruption of the anterior and middle columns, with variable degree of protrusion of the latter. This middle column posterior protrusion may extend into the spinal canal and be associated with an anterior cord syndrome.

Media file 10: (A) Normal lateral projection shows the relationships of anterior, posterior, and spinolaminar lines and prevertebral spaces. (B) Normal oblique projection shows the normal appearance of the laminae as shingles on a roof forming a regular elliptical curve with equal interlaminar spaces.

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Keywords

cervical spine fractures, cervical spine injuries, cervical vertebrae, odontoid fractures, atlanto-occipital dislocation, simple wedge fracture, flexion teardrop fracture, bilateral facet dislocation, clay shoveler fracture, unilateral facet dislocation, rotary atlantoaxial dislocation, hangman fracture, extension teardrop fracture, posterior neural arch fracture, Jefferson fracture, burst fracture, atlas fractures, atlantoaxial subluxation, occipital condyle fracturecentral cord syndrome, fracture of the posterior arch of C1, pillar fracture, anterior cord syndrome, fracture of transverse process of C2, upper cervical spine injuries, occiput to C2 injuries, cervical orthosis, neurogenic shock

Contributor Information and Disclosures

Author

Moira Davenport, MD, Attending Physician, Departments of Emergency Medicine and Orthopedic Surgery, Allegheny General Hospital
Moira Davenport, MD is a member of the following medical societies: American College of Emergency Physicians and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Mark Louden, MD, FACEP, Assistant Medical Director, Emergency Department, Duke Raleigh Hospital
Mark Louden, MD, FACEP is a member of the following medical societies: American Academy of Emergency Medicine and American College of Emergency Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Tom Scaletta, MD, President, Emergency Excellence (EmEx) (www.emergencyexcellence.com); Assistant Professor of Emergency Medicine, Rush Medical College, Cook County Hospital; Chairperson, Department of Emergency Medicine, Edward Hospital; Past-President, American Academy of Emergency Medicine
Tom Scaletta, MD is a member of the following medical societies: American Academy of Emergency Medicine and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Rick Kulkarni, MD, Assistant Professor of Surgery, Section of Emergency Medicine, Yale-New Haven Hospital
Rick Kulkarni, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: WebMD Salary Employment

The authors and editors of eMedicine gratefully acknowledge the contributions of previous authors, Jorma B Mueller, MD, Emilio Belaval, MD, and Simon P Roy, MD, to the development and writing of this article.

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