Cervical Spine Clearance

Both the NEXUS Low-risk Criteria and the Canadian C-spine rule are well validated and sensitive, and either can be used to determine the need for cervical spine imaging.

The Nexus study was prospectively validated in a large, multicenter, observational study. All patients with blunt trauma who underwent radiography of the cervical spine at any of the 21 participating emergency departments were included.

The Nexus study concludes that radiology is not necessary if patients satisfy ALL five of the following low-risk criteria:

1) Absence of posterior midline cervical tenderness

2) Normal level of alertness

3) No evidence of intoxication

4) No abnormal neurologic findings

5) No painful distracting injuries

The sensitivity, specificity and negative predictive value of using the nexus criteria to rule out cervical spine injury is 99.6%, 12.9%, and 99.9% respectively.

The Canadian C-spine rule is an alternate study that was performed to attempt to increase the specificity of the criteria to obtain cervical spine x-rays.  The Canadian C-spine Rules are as follows:

Condition One: Perform radiography in patients with any of the following:

1) Age 65 years or older

2)Dangerous mechanism of injury: fall from 1 m (3 ft) or five stairs; axial load to the head, such as diving accident; motor vehicle crash at high speed (>100 km/hour [>62 mph]); motorized recreational vehicle accident; ejection from a vehicle; bicycle collision with an immovable object, such as tree or parked car

 3) Paresthesias in the extremities

 Condition Two: In patients with none of the high risk characteristics listed in Condition One above, assess for any low-risk factor that allows for safe assessment of neck range of motion. The low-risk factors are as follows:

 1) Simple rear end motor vehicle accident; excludes: pushed into oncoming traffic; hit by bus or large truck; rollover; hit by high speed (>100 km/hour [>62 mph]) vehicle

 2) Sitting position in emergency department

 3) Ambulatory at any time

 
4) Delayed onset of neck pain

5) Absence of midline cervical spine tenderness

Patients without any of the low-risk factors listed here are NOT suitable for range of motion testing; they must be assessed with radiographs.  If a patient does exhibit any of the low-risk factors, perform range of motion testing, as described in Condition Three below.

Condition Three: Test active range of motion. Perform radiography in patients who are not able to rotate their neck actively 45 degrees both left and right. Patients able to rotate their neck, regardless of pain, do not require imaging.

The sensitivity, specificity and negative predictive value of using the Canadian C-spine rule to rule out cervical spine injury is 99.4%, 45.1%, and 100% respectively.

Clinicians should suspect a cervical ligamentous injury in an alert patient if severe neck pain, persistent midline tenderness, upper extremity paresthesias, or focal neurologic findings (eg, upper extremity weakness) are present despite a normal CT scan.

In the alert, cooperative patient, active F/E views using fluoroscopy and still images with at least 30 degrees of excursion in each direction may be sufficient to detect occult ligamentous and disc injuries

In one retrospective review, F/E radiographs were used to assess the presence of ligamentous cervical spine injury in 106 consecutive, awake, blunt trauma patients. Among patients with adequate studies, no ligamentous injuries were misdiagnosed. However, 32 patients could not flex or extend their neck sufficiently, making the studies inadequate. Of these 32 patients, four had sustained a cervical spine injury.

Use MRI in the obtunded patient or when Flex-Ex is not adequate.

 

Contributed by Dr. John Cull