Residency · Residency · Orthopedic Surgery

Cervical Spine Trauma: Evaluation and Clearance

Introduction

Cervical spine injuries occur in 2 to 5% of blunt trauma patients and carry significant morbidity and mortality due to the risk of spinal cord injury. Rapid, systematic evaluation and appropriate immobilization are paramount. The orthopedic surgeon must be proficient in the initial assessment, imaging interpretation, injury classification, and cervical spine clearance protocols.

Initial Assessment and Immobilization

The ATLS protocol guides the primary survey, with airway management taking priority. Cervical spine immobilization is maintained with a rigid collar until the c-spine is cleared. The log-roll technique is used for patient transfers to maintain spinal alignment. A cervical spine injury should be assumed in any patient with altered consciousness, high-energy mechanism, or distracting injury. The neurological examination includes motor and sensory assessment of all myotomes and dermatomes, rectal tone evaluation, and the bulbocavernosus reflex.

Clinical Clearance Rules

NEXUS Criteria

The NEXUS criteria indicate that cervical spine imaging is not required if all five criteria are met: no midline cervical tenderness, no focal neurological deficit, normal alertness, no intoxication, and no painful distracting injury. This approach has a sensitivity of 99.6% for clinically significant injury.

Canadian C-Spine Rule (CCR)

The CCR follows three steps. First, it asks whether any high-risk factor mandates imaging, such as age over 65, dangerous mechanism, or paresthesias. Second, it determines whether any low-risk factor allows safe range-of-motion assessment, such as a simple rear-end collision, ambulatory status, delayed onset of neck pain, or sitting in the emergency department. Third, it tests whether the patient can actively rotate the neck 45 degrees to each side. If full range of motion without pain is demonstrated, imaging is not required. The CCR is more specific than NEXUS with comparable sensitivity.

Imaging

CT is the primary imaging modality in trauma, with superior sensitivity for bony injury compared to radiographs and serving as the standard of care for moderate-to-high-risk patients. The three-view radiographic series (AP, lateral, odontoid) has been largely supplanted by CT in acute trauma. MRI is indicated for neurological deficits, suspected ligamentous injury, spinal cord injury evaluation, and clearance of obtunded patients. The evaluation focuses on fractures, dislocations, disc herniations, ligamentous disruption, epidural hematoma, and cord signal changes.

Classification of Cervical Spine Injuries

Upper Cervical Spine (Occiput-C2)

Occipital condyle fractures follow the Anderson and Montesano classification (Types I through III), with Type III avulsion fractures potentially associated with occipitocervical instability. Atlanto-occipital dissociation is often fatal, and survivors have severe neurological deficits. A basion-dens interval exceeding 12 mm on CT suggests this injury, and treatment is occipitocervical fusion.

Atlas (C1) fractures include the Jefferson fracture, a burst fracture with lateral mass displacement. The rule of Spence states that total lateral mass overhang exceeding 6.9 mm suggests transverse ligament rupture. Isolated anterior or posterior arch fractures are typically stable and treated with a collar. Transverse ligament injury requires MRI assessment, and rupture necessitates C1-C2 fusion.

Axis (C2) fractures include odontoid fractures, the most common C2 fracture. Type I is a tip avulsion (rare, usually stable). Type II is at the base of the dens (most common, with a nonunion rate of 5 to 40%); surgical fixation should be considered in elderly patients, displacement exceeding 5 mm, or posterior displacement. Type III extends into the C2 body and generally heals well with immobilization. Hangman's fractures (traumatic spondylolisthesis of C2) involve bilateral pars interarticularis fractures. The Levine-Edwards classification guides treatment: Type I is stable and treated with a rigid collar; Type II with greater than 3 mm displacement or angulation exceeding 11 degrees is treated with a halo or surgical fixation; Type IIA has significant angulation without translation, requires avoidance of traction, and is treated with surgical fixation; Type III involves C2-C3 facet dislocation and requires surgical fixation.

Subaxial Cervical Spine (C3-C7)

The SLICS (Subaxial Injury Classification and Severity Scale) guides treatment decisions based on morphology, disco-ligamentous complex integrity, and neurological status. A score below 4 indicates nonoperative treatment, a score of 4 may be treated either way, and a score above 4 indicates operative treatment. Compression fractures represent anterior column failure and are stable if height loss is less than 25% without posterior ligamentous injury. Burst fractures involve anterior and middle column failure, and canal compromise and neurological status must be assessed. Facet injuries may be unilateral (approximately 25% subluxation, possibly causing radiculopathy) or bilateral (greater than 50% subluxation with high association with spinal cord injury, requiring emergent reduction). Flexion-distraction injuries involve posterior tension band failure and are highly unstable.

Management Principles

Nonoperative Treatment

A rigid cervical collar is used for stable fractures with minimal displacement (such as isolated compression fractures and Type I or III odontoid fractures). A halo vest is used for selected unstable injuries amenable to external immobilization, though it is less commonly used today due to complications in the elderly. Duration is typically 6 to 12 weeks with serial imaging.

Operative Treatment

Indications include neurological deficit with cord compression, unstable injuries, irreducible dislocations, and SLICS greater than 4. Anterior approaches include ACDF and corpectomy with strut grafting, used for anterior compression, disc herniation, or vertebral body fractures. Posterior approaches include lateral mass or pedicle screw fixation with fusion, used for posterior instability, facet injuries, or long-segment stabilization. Combined anterior-posterior procedures are used for highly unstable injuries requiring circumferential stabilization.

Clearance of the Obtunded Patient

Clearance of the obtunded patient remains controversial, with institution-specific protocols. Options include high-quality CT alone (removing the collar if negative), CT plus MRI, and clinical clearance when the patient can be examined. Prolonged collar use in obtunded patients increases the risk of pressure ulcers, DVT, and ICU stay. The current trend favors CT-based clearance with collar removal if a high-quality CT is negative.

Clinical Pearls

The NEXUS or Canadian C-Spine Rule should be used to determine if imaging is required in alert trauma patients. CT is the primary imaging modality for cervical spine trauma, while MRI is essential for neurological deficits and ligamentous injury assessment. Type II odontoid fractures have the highest nonunion rate and often require surgical fixation, especially in the elderly. Bilateral facet dislocations are an emergency requiring urgent closed or open reduction to decompress the spinal cord. The SLICS score provides an evidence-based framework for operative decision-making in subaxial injuries.

References

1. 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." New England Journal of Medicine. 2000;343(2):94-99.
2. 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.
3. Vaccaro AR, Hulbert RJ, Patel AA, et al. "The Subaxial Cervical Spine Injury Classification System: A Novel Approach to Recognize the Importance of Morphology, Neurology, and Integrity of the Disco-Ligamentous Complex." Spine. 2007;32(21):2365-2374.
4. Grauer JN, Shafi B, Hilibrand AS, et al. "Proposal of a Modified, Treatment-Oriented Classification of Odontoid Fractures." Spine Journal. 2005;5(2):123-129.

Read this lecture as Markdown