Residency · Residency · Neurosurgery
Cervical Spine Clearance in the Trauma Patient
Introduction
Cervical spine clearance is a critical component of trauma evaluation. Failure to identify cervical spine injuries can result in devastating neurological consequences, while prolonged unnecessary immobilization carries its own morbidity including pressure ulcers, dysphagia, elevated ICP, and delayed mobilization. Validated clinical decision rules and systematic protocols guide safe and efficient clearance.
Epidemiology
Cervical spine injury occurs in 2 to 5 percent of all blunt trauma patients, rising to 5 to 10 percent in patients with severe TBI and GCS of 8 or below. The most commonly injured levels are C2, primarily odontoid fractures, and C5 to C7 in the subaxial spine. Spinal cord injury accompanies approximately 1 to 3 percent of cervical fractures. Missed cervical spine injuries occur in 2 to 5 percent of trauma patients when systematic protocols are not followed.
Clinical Decision Rules
NEXUS Criteria
The National Emergency X-Radiography Utilization Study established that cervical spine imaging is not required if all five criteria are met: no posterior midline cervical tenderness, no focal neurological deficit, normal alertness with GCS of 15, no intoxication, and no painful distracting injury. This rule achieves a sensitivity of 99.6 percent for clinically significant injuries and was validated in over 34,000 patients.
Canadian C-Spine Rule
The Canadian C-Spine Rule is a three-step decision algorithm. First, high-risk factors mandating imaging include age 65 or older, dangerous mechanism, and paresthesias in the extremities. Second, low-risk factors allowing safe range-of-motion assessment include simple rear-end motor vehicle collision, sitting position in the emergency department, ambulatory at any time, delayed onset of neck pain, and absence of midline tenderness. Third, the patient is assessed for active range of motion, specifically whether they can rotate the neck 45 degrees to each side. This rule achieves 99.4 percent sensitivity with specificity superior to NEXUS. It cannot be applied to patients with GCS below 15.
| Decision Rule | Criteria for No Imaging | Sensitivity | Applicability |
|---|---|---|---|
| NEXUS | No midline tenderness, no focal deficit, alert (GCS 15), no intoxication, no distracting injury | 99.6% | All alert trauma patients |
| Canadian C-Spine Rule | 3-step algorithm: high-risk factors → low-risk factors → ROM assessment | 99.4% | Alert (GCS 15) patients only |
Imaging Modalities
CT Cervical Spine
CT is the primary imaging modality for all trauma patients requiring cervical spine imaging. Plain radiographs are no longer adequate as primary screening. CT sensitivity exceeds 99 percent for bony injuries. The study must include occiput to T1 with sagittal and coronal reformats. Evaluation includes vertebral body alignment, fractures, facet joints, the spinolaminar line, and prevertebral soft tissue swelling.
MRI Cervical Spine
MRI is indicated for neurological deficits, suspected ligamentous injury, obtunded patients with abnormal CT, or persistent symptoms with normal CT. It is superior for evaluating spinal cord injury, disc herniation, ligamentous disruption including the PLL, ALL, and interspinous ligaments, and epidural hematoma. STIR and T2 sequences are most sensitive for soft tissue and cord injury. Timing is ideally within 24 to 72 hours of injury for optimal sensitivity.
CT Angiography
CTA is considered with fractures involving the transverse foramen due to vertebral artery injury risk, and with facet dislocations, especially with subluxation. Vertebral artery injury occurs in 20 to 40 percent of unilateral and bilateral facet injuries.
Clearance Protocols by Patient Category
Alert and Oriented Patients
For patients with GCS of 15, the NEXUS or Canadian C-Spine Rule is applied. If criteria are met, the collar is removed without imaging. If criteria are not met, CT cervical spine is obtained. Normal CT with persistent pain may warrant MRI or flexion-extension radiographs at follow-up.
Obtunded or Intubated Patients
CT cervical spine is mandatory. If CT is normal, two approaches remain debated. The traditional approach obtains MRI within 24 to 72 hours to exclude ligamentous injury before collar removal. Growing evidence, including NEXUS2 data and systematic reviews, supports clearance based on high-quality CT alone in obtunded patients, as the risk of an unstable ligamentous injury missed by CT is exceedingly low. If CT is abnormal, MRI provides further characterization and surgical planning. The collar should be removed as soon as safely possible to reduce complications of prolonged immobilization.
Pediatric Patients
Children have a higher proportion of upper cervical injuries at the occiput to C2 level due to the large head-to-body ratio. SCIWORA, or spinal cord injury without radiographic abnormality, is more common in children under 8 years. CT radiation concerns are significant; MRI is preferred when safe. Clinical clearance by examination is appropriate in fully cooperative, alert children.
Common Cervical Spine Injuries
Upper Cervical
Occipital condyle fractures are diagnosed by CT, and craniocervical stability must be assessed. Atlanto-occipital dislocation is often fatal; survivors require occipitocervical fusion. C1 Jefferson fractures are axial load burst fractures of the atlas ring. C2 odontoid fractures are classified as Type I at the tip, Type II at the base which is most common with the highest nonunion rate, and Type III extending into the body. C2 hangman fractures are bilateral pars interarticularis fractures.
Subaxial Cervical
Compression fractures involve anterior column failure and are stable if height loss is less than 25 percent. Burst fractures involve anterior and middle column failure with retropulsed fragments into the canal. Facet injuries range from unilateral subluxation to bilateral dislocation. Teardrop fractures result from flexion-compression and are unstable with posterior ligament disruption. The SLIC (Subaxial Cervical Spine Injury Classification) score guides surgical decision-making.
Complications of Prolonged Immobilization
Pressure ulcers develop at the occiput and chin within hours in obtunded patients. Cervical collars restrict swallowing mechanics, increasing dysphagia and aspiration risk. Collars may impede jugular venous drainage, elevating ICP. Patient discomfort and agitation are common in the ICU setting. Delayed mobilization impacts rehabilitation and recovery.
Clinical Pearls
Plain radiographs are insufficient for cervical spine clearance in trauma; CT is the primary imaging modality with sensitivity exceeding 99 percent for fractures. In obtunded patients with a normal high-quality CT, there is growing evidence that the risk of an unstable ligamentous injury missed by CT alone is exceedingly low; however, institutional protocols vary, and MRI remains widely used for definitive clearance. Cervical collars should be removed as soon as the spine is cleared; prolonged immobilization causes measurable harm including pressure injury, dysphagia, and elevated ICP. All patients with cervical facet fractures or dislocations should undergo CT angiography to evaluate for vertebral artery injury, which occurs in up to 40 percent of bilateral facet dislocations.
References
- Hoffman JR, Mower WR, Wolfson AB, et al. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma (NEXUS). N Engl J Med. 2000;343(2):94-99.
- Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. JAMA. 2001;286(15):1841-1848.
- Patel MB, Humble SS, Cullinane DC, et al. Cervical spine collar clearance in the obtunded adult blunt trauma patient: a systematic review and practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2015;78(2):430-441.
- Vaccaro AR, Hulbert RJ, Patel AA, et al. The subaxial cervical spine injury classification system. Spine. 2007;32(21):2365-2374.