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.
In pediatric patients, the spine is more flexible, and therefore, neural damage occurs much earlier than musculoskeletal injury in young patients. Because of this high flexibility, fatal consequences can occur with sometimes even minimal structural damage. Compared to adults, children have a different fulcrum because of a relatively large head, the vertebrae are not completely ossified, and the ligaments are firmly attached to articular bone surfaces that are more horizontal, making the pathophysiology of injury in children different from that in adults.
Evaluation of injury
When a cervical spine injury is suspected, neck movement should be minimized during transport to the treating facility. Ideally, the patients should be transported 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.
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. Care must be taken while managing the airway in patients with potential cervical spine injuries. Video-assisted intubation should be considered to limit cervical spine motion during the process of securing the airway.
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.
Radiographic evaluation is indicated in the following
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
A standard trauma series is composed of 5 views: cross-table lateral, swimmer’s, oblique, odontoid, and anteroposterior. Approximately 85-90% of cervical spine injuries are evident in lateral view, making it the most useful view from a clinical standpoint.
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.