History
Fracture or dislocation of the cervical spine should be suspected in any patient involved in a high-velocity injury. Successful treatment starts with appropriate transportation of the patient from the scene of the accident to the trauma center. Airway, breathing, and circulation (the ABCs) should always be the highest priority. Immobilization of the cervical spine with sandbags or a cervical collar and placement of the patient on a long spine board help prevent secondary injury. Transfers and intubation should be accomplished under strict spine precautions.
An initial history should be taken, and mental status and consciousness level should be assessed. Important points to note are whether the patient was thrown from the vehicle, whether the patient hit his or her head, and whether any indication of paralysis was present at the time of the accident. Voluntary actions, neurologic function, and regions of pain also should be noted.
Physical Examination
The patient should be inspected thoroughly for lacerations or abrasions on the scalp, face, neck, or shoulders as clues to the mechanism of injury. The back of the neck should be palpated for any tenderness, stepoff, or hematoma.
A thorough neurologic examination should be performed as soon as possible to detect any evidence of cord damage. It should follow the standards established by the American Spinal Injury Association (ASIA). [7] Motor strength is graded on a scale of 0-5 in all major myotomes.
A systematic sensory examination is performed to detect light touch, pinprick, and proprioception in all key dermatomes of the trunk and extremities. Deep tendon reflexes are recorded. These include the biceps (C5), triceps (C7), and brachioradialis (C6) for the upper extremities, along with the patella (L4) and Achilles (S1) for the lower extremities.
The presence of pathologic reflexes also should be noted. Clonus is a sustained, repetitive, involuntary contraction of a major muscle group, usually seen in the Achilles and recorded as the number of "beats" or contractions sustained. The Hoffman sign is seen in the hands with forced passive flexion of the distal interphalangeal (DIP) joint of the long finger causing a reflex contraction of the flexors of the index finger and thumb. The Babinski sign is seen when the toes exhibit an upward motion as opposed to a downward motion in response to a stroking stimulus on the bottom of the foot.
Particular emphasis should be placed on the examination of the sacral roots and reflexes. These are extremely important for two reasons. First, detection of sacral sparing indicates an incomplete spinal cord injury (SCI). Second, return of the sacral reflexes indicates the passing of spinal shock. Anal sphincter tone and perianal sensation are good tests of sacral root function. The bulbocavernosus reflex and anal wink are good tests of the sacral reflex arc.
Repeating examinations serially is crucial to determine the end of spinal shock, which usually occurs in 24 hours. Serial examinations also help determine whether an incomplete lesion is improving or worsening. This facilitates definition of the best treatment pathway.
Classification
Methods of classifying subaxial cervical spine injuries have included the Holdsworth, Allen, and Harris systems, along with the Subaxial Injury Classification (SLIC; first described by Vaccaro et al [8] ) and severity scale and the Cervical Spine Injury Severity Score (CSISS). The Congress of Neurological Surgeons recommended the SLIC and the CSISS for use in categorizing lower cervical spine injuries. [9]
The SLIC assigns points within three categories—morphology, discoligamentous complex (DLC), and neurologic status—to derive a score. With respect to morphology, points are assigned as follows:
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No abnormality - 0
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Compression - 1
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Burst - +1 = 2
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Distraction - 3
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Rotation/translation - 4
With respect to the DLC, points are assigned as follows:
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Intact - 0
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Indeterminate - 1
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Disrupted - 2
With respect to neurologic status, points are assigned as follows:
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Intact - 0
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Root injury - 1
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Complete cord injury - 2
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Incomplete cord injury - 3
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Continuous cord compression in setting of neurologic deficit - +1
The AOSpine organization used a consensus process among clinical experts to develop a subaxial cervical spine injury classification system. [10] This system is based on the following three injury morphology types:
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Compression injuries (A)
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Tension band injuries (B)
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Translational injuries (C)
There are additional descriptions for facet injuries (types F1-F4), as well as patient-specific modifiers and neurologic status. [11] Initial assessment showed this classification system to have good intraobserver and interobserver reliability for all injury subtypes. However, a study by Cabrera reported significant variability in diagnostic accuracy for fractures with F1-F3 facet morphology, though there was almost universal agreement for F4. [12]
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Cross-sectional anatomy of the cervical cord.
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Normal anatomy of the lower cervical spine.
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Lateral film of a C5 burst/teardrop fracture.
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Sagittal CT scan of C5 burst fracture.
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Axial CT scan of C5 burst fracture.
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Reduction of C5 burst fracture after tongs traction.
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Postoperative image of C5 burst fracture; note anterior and posterior fixation.
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Postoperative image of C5 burst fracture.
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Standard lateral cervical spine of an 80-year-old patient after a motor vehicle accident; patient has no neurologic deficits and no neck pain.
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Swimmer's view of the same 80-year-old patient as in Image 9; note the C7-T1 fracture/dislocation.
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Axial CT scan of C7-T1 fracture/dislocation.
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Sagittal CT of C7-T1 fracture/dislocation.
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MRI of C7-T1 fracture/dislocation.
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Reduction of C7-T1 fracture/dislocation.
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Postoperative anteroposterior view of C7-T1 fracture/dislocation.
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Postoperative lateral view of C7-T1 fracture/dislocation.
