Clearing the cervical spine

A medical history and physical examination can be sufficient in clearing the cervical spine. Notable clinical prediction rules to determine which patients need medical imaging are the Canadian C-spine rule and the National Emergency X-Radiography Utilization Study (NEXUS).^[2]

The following is based on the NEXUS (National Emergency X-Radiography Utilization Study) criteria.^[3]

Excluding a cervical spinal injury requires clinical judgement and training.

Under the NEXUS guidelines, when an acute blunt force injury is present, a cervical spine is deemed to not need radiological imaging if all the following criteria are met:

• There is no posterior midline cervical tenderness
• There is no evidence of intoxication
• The patient is alert and oriented to person, place, time, and event
• There is no focal neurological deficit (see focal neurological signs)
• There are no painful distracting injuries (e.g., long bone fracture)

• In children, a CT scan of the neck is indicated in more severe cases such as neurologic deficits, whereas X-ray is preferable in milder cases, by both US^[4] and UK^[5] guidelines. Swedish guidelines recommend CT rather than X-ray in all children over the age of 5.^[6]
• In adults, UK guidelines are largely similar as in children.^[5] US guidelines, on the other hand, recommend CT in all cases where medical imaging is indicated, and that X-ray is only acceptable where CT is not readily available.^[7]

Magnetic resonance imaging may be useful if it is necessary to exclude a ligament injury.^[8] The indication for MR spine is a focal neurological deficit. Another indication for MR of the cervical spine is persistent mid-line neck pain or tenderness despite a normal CT in the awake patient.

X-ray consists of a three view cervical x-ray series, adding a swimmer's view if the lateral doesn't include the C7/T1 interface.

CT scan should be thin slices, ideally 1.5 mm or less.^[9] It should include first thoracic vertebra.^[10]

CT scan or X-ray images are evaluated for the presence or absence of directly visible fractures. In addition, indirect signs of injury by the vertebral column are incongruities of the vertebral lines,^[11] and/or increased thickness of the prevertebral space:^[12]

• 
  X-ray of normal congruous vertebral lines
• 
  CT scan of normal congruous vertebral lines.^[11]
• 
  CT scan with upper limits of the thickness of the prevertebral space at different levels.^[12]

If the patient is not expected to be clinically evaluable within 48–72 hours because of severe head or multiple injuries, they should remain immobilized until a time when such an examination is possible. A 64-slice CT with reconstructions does not entirely rule out ligamentous injury leading to instability, but is a practical means of identifying the majority of C-spine injuries in obtunded patients. MR C-spine has frequent false-positives, limiting its usefulness.^{[citation needed]} In these cases, a consultation with a Spine Surgery specialist is prudent.

• Cervical fracture
• Spinal cord injury