Question 10

College Answer

This is a controversial area with no consensus. Aim is to test understanding of literature on cervical spine injury, sensitivity and limitations of imaging, risk Vs benefits, understanding of institutional protocols and systems issues. A well reasoned and an appropriate approach would score high marks. 

A suggested  approach is

1.   Detailed history and clinical exam with review of mechanism of injury, speed, other injuries

2.   3 view (AP, lateral and peg view) or 5 view( 3 + right and left obliques) cervical spine  with focussed CT to missed areas or CT scan of neck from base of skull to upper thoracic vertebrae with reconstructions.

3.   If CT scan normal after interpretation by specialist radiologist and ortho spine/neurosurgeon/ICU specialist then neck is “clear”.

4.   MRI if clinically suspected spinal neurological injury or abnormal CT scan or very high risk cord injury ( high speed, ejection from vehicle, high ISS)

5.   Transfer to specialised trauma centre.

Justification

1.   5-10 % of patients with a severe head injury have an associated unstable cervical fracture.

2.   Clinical clearance not possible here.

3.   Maintaining cervical/spinal  immobility via a cervical collar until clinical clearance increases the risk of pressure areas,  pneumonia and raised intracranial pressure.

4.   3 and 5 view cervical X rays are frequently of inadequate quality and detect 75-
90% of unstable injuries even when of adequate quality and correctly interpreted.

5.   Multislice CT scan from the base of skull to upper thoracic spine with sagittal and coronal reconstructions will detect most injuries.  It may miss an unstable ligamentous injury without bone fracture (risk 1/1000). It is convenient to image the neck at the same time as the CT brain scan or other CT scans

6.   MRI will detect spinal cord and soft tissue pathology such as ligamentous injury, spinal cord injury and epidural haematoma.

Additional Marks:
•    Role of flexion extension views
•    Requirements for clinical clearance
•    Timing of clearing cervical spine Vs attending to other life threatening injuries
•    Institutional Protocols

Discussion

Details regarding the clearance of the C-spine in the unconscious patient are discussed elsewhere.The rules seem to have changed somewhat since this answer was written, and these days we dont tend to ask for flexion-extsnion views and lateral C-spine Xrays very often.

In short, the algorithm one should follow ought to resemble the excellent Alfred algorithm, which incorporates evidence from the post-CT era. Remember that many of the early studies were done on CT scanners with 2.5mm slices, or thicker - these days the resolution is substantially better than that.

• If the patient is unconscious and the C-spine cannot be cleared by the NEXUS criteria, the patient should have full spinal precautions.
• A CT of the C-spine should be performed as soon as the process of trauma resuscitation permits- ideally, as a part of a CT trauma series.
• A CT will miss a few ligamentous injuries, but very few of these are clinically significant.
• If the CT is normal (and senior radiology or neurosurgical staff agree that it is normal), the collar can be taken off. However, if the mechanism of injury strongly favours C-spine trauma, one may choose to perform an MRI anyway.
• One should ignore the normal CT if there is evidence of spinal cord injury (eg. focal neurological signs unexplained by the head injury) or if the mechanism suggests that such an injury might be present.
• One should perform an MRI wherever there is CT abnormality suggestive of ligamentous injury. One should guard against misinterpreting the medicolegally defensive wording of the CT reports, which inevitably whinge that "ligamentous injury cannot be excluded".
• Wherever CT and MRI are available, one should never agion order flexion-extension views, as they are essentially useless and add nothing.

The Alfred Spinal Clearance Protocol

Lien, D., T. Jacques, and K. Powell. "Cervical spine clearance in Australian intensive care units." Critical Care and Resuscitation 5.2 (2003): 91.

Cooper, D. J., and H. M. Ackland. "Clearing the cervical spine in unconscious head injured patients-the evidence." Critical Care and Resuscitation 7.3 (2005): 181.

Hennessy, Deirdre, et al. "Cervical spine clearance in obtunded blunt trauma patients: a prospective study." The Journal of Trauma and Acute Care Surgery68.3 (2010): 576-582.

Como, John J., et al. "Is magnetic resonance imaging essential in clearing the cervical spine in obtunded patients with blunt trauma?." Journal of Trauma-Injury, Infection, and Critical Care 63.3 (2007): 544-549.

Tran, Baotram, Jonathan M. Saxe, and Akpofure Peter Ekeh. "Are flexion extension films necessary for cervical spine clearance in patients with neck pain after negative cervical CT scan?." Journal of Surgical Research 184.1 (2013): 411-413.

Sierink, J. C., et al. "Systematic review of flexion/extension radiography of the cervical spine in trauma patients." European journal of radiology 82.6 (2013): 974-981.