Chapter 10 – Cervical Spine Trauma




Abstract




Injury of the cervical spine occurs most commonly due to high impact blunt trauma.13 It is the most commonly injured portion of the spine as it is not as well protected as the lower thoracic and lumbar spine. The most commonly injured vertebrae are C2 and C5–7, and injuries are more common in males than females.1,2,4





Chapter 10 Cervical Spine Trauma



Katja Goldflam


Injury of the cervical spine occurs most commonly due to high impact blunt trauma.13 It is the most commonly injured portion of the spine as it is not as well protected as the lower thoracic and lumbar spine. The most commonly injured vertebrae are C2 and C5–7, and injuries are more common in males than females.1, 2, 4



Anatomy


The cervical spine consists of seven vertebrae, including the atlas and axis (C1 and C2, respectively), that permit rotation of the head on the spinal column. Multiple ligaments hold the bony components in place, giving rise to the three columns of the cervical spine described by Denis5 (Table 10.1). Any single column injury may be considered stable, while two-column injuries result in greater mobility, and three-column injuries are always unstable.




Table 10.1 Spinal columns















Anterior column Anterior longitudinal ligament, anterior annulus fibrosus, as well as anterior half of vertebral body, and adjacent intervertebral disk
Middle column Posterior longitudinal ligament and posterior annulus fibrosus, as well as posterior half of vertebral body, and adjacent intervertebral disk
Posterior column Posterior ligamentous complex, transverse and spinous processes, pedicles, laminae, and facet joints


History and Physical Examination




  • Patients most often have a known history of trauma, with high energy blunt trauma being the most common etiology.1, 2



  • Unconscious or altered patients who are unable to provide a reliable history or physical examination should raise suspicion for cervical spine injury in the appropriate clinical setting.



  • Pain with or without range of motion of the neck is common.



  • Paresthesias, focal weakness, and other focal neurologic deficits may occur.



  • A rectal examination should be performed to assess for rectal tone.



  • Patients may have external signs of trauma, tenderness to palpation over the midline, or step-offs on examination of the cervical spine.



  • Though used in validated clinical guidelines and part of the current EAST practice management guidelines,6 the reliability of the physical examination has been questioned. One study found the clinical examination, defined as neck pain, external trauma, neurologic deficit, or tenderness or other palpable abnormalities over the cervical spine to be 76.9% sensitive with a negative predictive value 95.7% when compared to CT findings.7



Immobilization




  • When suspicion for injury exists, the cervical spine should be immobilized with in-line stabilization in a rigid collar until imaging is obtained.8



  • Alternatively, the collar may be cleared clinically using the NEXUS or Canadian C-spine criteria, as detailed in the next section.911



  • Patients that have persistent symptoms, such as midline tenderness to palpation, should remain immobilized in a cervical collar until an MRI can be performed to evaluate for ligamentous injury or appropriate follow up is arranged.12, 13



  • Recent debate has focused on the possible harms of cervical spine immobilization, including raised intracranial pressure in patients with head injury, delays in resuscitation, and complications of airway management,14, 15 however it remains the current standard of care.



Decision to Image





  • Two commonly used criteria to help decide when imaging is appropriate are the NEXUS and Canadian Cervical Spine Rule.



  • NEXUS:9




    • These five criteria have been validated with a 100% sensitivity of excluding cervical spine fractures, with original studies utilizing C-spine radiographs and not CT.



    • If absence of all five criteria are met, the cervical collar can be removed safely without any imaging (Box 10.1).



  • Canadian C-spine Rule:10, 11, 16




    • This rule allows for clearance of a greater number of patients when compared to NEXUS (Table 10.2).




  • Exclusion criteria:




    • Non-trauma patients



    • GCS <15



    • Unstable vital signs



    • Age <16 years



    • Acute paralysis



    • Known vertebral disease



    • Previous cervical spine surgery



  • Application of the rule:




    • Patients with ANY high-risk criteria should be imaged.



    • Patients without high risk criteria but who DO NOT MEET ANY low risk criteria should be imaged.



    • Patients who have NO high-risk criteria and AT LEAST ONE low-risk criteria should be asked to range their neck 45° left and right; if unable to do so, they should be imaged (some pain is acceptable as long as the range of motion is not limited).



There is some evidence to suggest that, in patients older than 55 years, midline tenderness of the cervical spine may not be a good enough indicator of injury, and that more liberal use of imaging should be considered.17




Box 10.1 NEXUS Criteria9




  • Midline tenderness



  • Neurologic deficits



  • Altered mental status



  • Intoxication



  • Distracting injury




Table 10.2 Canadian C-spine rule












High-risk criteria Age >65, paresthesias in any extremities, dangerous mechanism
Low-risk criteria Sitting position in the ED, ambulatory at any time, delayed onset of neck pain, no midline tenderness


Imaging




  • Patients who meet the above criteria or are in some other way considered high-risk should undergo imaging.



  • Plain radiographs have largely been replaced by CT as the preferred imaging modality.6



  • Certain patients with low suspicion for injury and expected normal anatomy (i.e. no history of arthritis, osteoporosis, etc.) may be considered for evaluation by plain radiographs, but the sensitivity for acute fractures is limited.4, 18, 19



  • One such meta-analysis by Holmes and Akkinepalli18 in 2005 showed a pooled sensitivity for plain radiographs of 52% and 98% for CT.



  • Plain radiographs include three views:




    • Lateral



    • Anteroposterior



    • Odontoid



  • CT scans should visualize the entire cervical spine from the occiput of the skull to the junction of C7 and T1 for complete imaging.



  • In patients with fractures found on CT completion, imaging of the entire spine should be performed, as up to 19% of patients may have additional non-contiguous vertebral fractures in the cervical, thoracic, or lumbar spine.3, 20



  • MRI should be obtained in patients with concern for ligamentous or spinal cord injury, including patients with normal CT scans with persistent pain or neurologic findings.12, 13



  • Flexion/extension views should not be used in obtunded patients. While they may be considered in alert patients if MRI is not available,21, 22 a recent review by Oh et al.23 in 2016 shows their diagnostic value is likely limited and that they add little further information to a negative CT scan.



  • Vascular imaging with CTA or MRA should be considered in patients where there is concern for injury to the vessels, including with fractures to the skull base or foramina.2426



Types of Fractures/Patterns




  • These depend on the location of injury, as well as the mechanism of trauma.



  • Injuries to the atlas (C1) and axis (C2) are often unstable, which include:




    • Occipital condyle fracture



    • Atlanto-occipital dislocation



    • Atlanto-axial dislocation



    • Jefferson (burst) fracture of C1 (Figure 10.1)



    • Odontoid/dens fracture of C2 (Figure 10.2)



    • Hangman’s fracture of C2 (Figure 10.3)



  • Fractures of the C3–7 vertebrae vary in stability and are classified by the pattern of injury:5, 2729




    • Compression-flexion



    • Compression-extension



    • Vertical compression (axial loading)



    • Distraction-flexion



    • Distraction-extension



    • Lateral flexion





Figure 10.1 Jefferson burst fracture of C1


(image courtesy of Hellerhoff, reproduced here under CC BY-SA 3.0 license creativecommons.org/licenses/by-sa/3.0/)




Figure 10.2 Type 2 dens fracture


(images courtesy of James Heilman, MD, reproduced here under CC BY-SA 4.0 license creativecommons.org/licenses/by-sa/4.0/)




Figure 10.3 Hangman’s fracture of C2


(images courtesy of Lucien Monfils, reproduced here under CC BY-SA 3.0 license creativecommons.org/licenses/by-sa/3.0/)


General ED Management




  • Immobilization should be maintained in all patients with known fractures; a padded collar should be used to prevent pressure sores and discomfort with long-term wear.30



  • Adequate pain control should be ensured.



  • Neurologic checks should be performed periodically to recognize any deterioration in neurologic status early.



  • Need for surgical intervention will depend on the fracture pattern, (specifically stability vs instability), evidence of neurologic compromise (e.g. from nerve impingement, edema, or hematoma), as well as patient characteristics and suitability for operative repair.




    • This should be determined by a consultant spine surgeon.



  • Reasons for admission include:




    • Unstable fracture patterns



    • Planned surgical intervention



    • Neurologic deficits



    • Concern for possible progressive decompensation



    • Additional significant injuries requiring monitoring or intervention



    • Lack of a safe disposition plan



  • Patients with stable fractures, clear follow up plans, and no safety concerns may be considered for discharge.



  • Strict return precautions should include any change in or worsening of symptoms, including pain and neurologic complaints.



Airway Management




  • High cervical spine neurologic injuries likely result in respiratory compromise.



  • Trauma to the C1–3 vertebrae and adjacent spinal cord is most likely to cause phrenic nerve injury, though patients with injury up to C5 are at risk.



  • Phrenic nerve injury will result in paralysis of the diaphragm and respiratory depression.



  • Additional trauma around the area of the cervical spine may be indicative of proximal airway injury, including airway edema, soft tissue swelling, or expanding hematomas, and a low threshold for intubation should be maintained.



  • In emergent cases, rapid sequence intubation should be performed while strict in-line stabilization is maintained.31



  • When the clinical situation permits and intubation is performed on a more elective basis, awake fiberoptic intubation allows for minimal movement and exacerbation of injury.



Steroids


Based on current data, steroids are not recommended in patients with spinal cord injury.32




  • No conclusive Class I or II evidence of beneficial effects exists, and Class III data is methodologically limited or inconsistent.



  • Harmful side-effects reported included wound infections and other infectious complications, hyperglycemia, and GI hemorrhage, as well as higher mortality unrelated to severity of injuries.



Complications





  • Additional traumatic injuries may be present, including trauma to lower parts of the spine, and should be evaluated appropriately.3, 20




    • In one series, 57% of patients had additional extra-spinal injuries, and 19% had non-contiguous spinal trauma.20



  • Neurological findings may be suggestive of complete or partial spinal cord injury.




    • Complete spinal cord injury: complete loss of motor and sensory function below the level of injury.



    • Partial spinal cord syndromes are shown in Table 10.3.33, 34



  • Spinal cord injury without radiographic abnormality (SCIWORA) is a rare but important clinical entity, the definition of which is changing in the era of MRI.33, 35




    • Strong evidence-based recommendations for management are missing due to the diversity of patients included in this definition.



    • Recently developed MRI classifications are being used for prognostication based on imaging patterns.35



  • Hypotension:




    • Hemorrhagic shock should be considered as the etiology in any trauma patient.



    • Neurogenic shock may occur secondary to decreased sympathetic output after injury to the upper spinal cord; the resultant unopposed vagal tone causes vasodilation and hypotension without the expected reflexive tachycardia (i.e. a relative bradycardia).33, 36



    • In patients unresponsive to resuscitation with fluids or blood, vasopressors should be initiated for presumed neurogenic shock. A mean arterial pressure goal of 80 mm Hg is recommended.



  • Spinal shock describes the neurologic findings that accompany the acute period of injury to the spinal cord.




    • The deficits may be temporary, and permanent deficits can only be confirmed once the shock period has passed.



    • Absent bulbocavernosus and cremasteric reflexes confirm the diagnosis.33



  • Vascular injuries are most common in patients with hyperextension or hyperflexion mechanisms, fractures at the base of the skull or of the vascular foraminae, and especially in patients with C1–3 injuries.2426





Table 10.3 Partial spinal cord syndromes















Central cord syndrome Cervical motor weakness of upper extremities greater than lower extremities
Hemisection (Brown-Sequard) syndrome Ipsilateral motor and proprioception/light touch loss; contralateral pain and temperature sensation loss
Anterior cord syndrome Motor function and pain/temperature sensation loss; sparing of light touch and proprioception


Clinical Clearance of Cervical Spine


In patients with negative imaging, the collar should be opened anteriorly, and the posterior midline should be re-examined for tenderness to palpation. Patients with persistent pain or tenderness should remain with the collar in place. When no midline tenderness is found, patients should be asked to range their neck left and right 45° in each direction, as well as up and down; if this does not elicit any discomfort the collar can be safely removed.10, 37



Consultation Indications


Any patient with evidence of cervical spine fracture or neurologic injury should be evaluated by an appropriate consultant, either a neurologic or orthopedic spine surgeon. Involvement of social work or a care management team may be beneficial when any long-term safety or disposition concerns exist.



Pitfalls in ED Management




  • Not maintaining appropriate cervical spine immobilization



  • Not managing airway early



  • Not considering additional traumatic injuries



  • Not imaging the remainder of the spine3, 20



  • Not considering vascular injury, especially in higher cervical spine lesions (C3 and above)




Key Points




  • Immobilization prior to imaging in any patient with concern for cervical spine injury is recommended.



  • CT scans should be the first line of imaging.



  • MRI (or appropriate follow up if not available) should be obtained if concern for ligamentous injury remains after negative CT imaging.



  • Use the NEXUS or Canadian C-Spine Rule when considering imaging.



  • Consider complications including neurologic injury without bony trauma, spinal shock, vascular injuries, and SCIWORA.



  • Clinically clear the cervical spine when appropriate.



  • Ensure appropriate consultation and follow up when indicated.


Jan 10, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 10 – Cervical Spine Trauma
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