Evaluation of Cervical Spine Trauma in Children

Cervical Spine Clearance in Trauma Patients

• Clearance protocols: Many trauma centers have a protocol (e.g. Great Ormond Street Cervical Spine Clearance Protocol)  that allows ER or trauma surgery staff to clear a patient’s cervical spine without consulting a neurosurgeon (60). These protocols are helpful but must necessarily be very strict. Although a neurosurgeon may choose to deviate from this protocol when evaluating a patient for cervical spine clearance, knowledge of the strict requirements is very useful.

Examination

• Determine examination made in the field: It is helpful to determine what the examination was on the scene and on arrival to ER in addition to the current examination.
• Formal examination including rectal tone and bulbocavernosus reflex if possible: Neurological examination should include, to the extent possible, level of alertness, strength, rectal tone, and BCR. If no formal examination was performed prior to sedation and intubation, then ER staff can usually tell about vocalizations and gross strength of each limb.

Presentations of Specific Types

Various osseous and ligamentous injuries to the cervical spine are recognized in children:

• Atlanto-occipital dislocation: This is two and a half times more likely in children than adults (47),and, unlike in adults, it can be mild with no associated neurological impairment. The atlanto-occipital joint is severely disrupted, usually as a result of high-velocity MVAs where it can accounnnt for up to 35% of injuries to the spine. Associated high cervical spinal cord injury frequently co-exists (55). The injury is commonly fatal. In children who survive, there is often a history of cardiorespiratory arrest and emergency resuscitation at the scene. The injury canbe easily missed on both x-ray and CT because joints may re-approximate between the incident and the time of imaging.Multiple methods exist to determine the presence of atlanto-occipital dislocation; however, if the bony aspects have re-approximated, only careful examination of the MRI may reveal the injury (39)This injury is highly unstable and requires internal fixation and fusion.
• Atlanto-axial subluxation:The injury implies disruption of the transverse ligament and usually occurs as a result of hyperflexion. Traumatic atlanto-axial subluxation is rare in children, as more commonly this mechanism of injury will lead to fracture of the odontoid rather than rupture of the transverse ligament, which is stronger in this age group.
• AARF: There is fixed subluxation of the atlanto-axial articulation due to excessive rotation. The clinical presentation is with painful torticollis; the preceding trauma may be quite innocuous. This injury is rarely seen in adults and likely reflects the greater range of rotational movement available in children because of their more lax ligaments as well as the planar configuration of the lateral masses.
• Jefferson fracture: An injury to the C1 ring as a result of axial loading. It is uncommon in young children because of the cartilaginous nature of the C1 ring at this age.
• Odontoid fracture: Fractures of the odontoid occur more commonly in adults than in children. In children, a particular form of odontoid fracture is epiphysiolysis; this is a fracture through the dentocentral synchondrosis, usually as a result of hyperflexion injury.
• Hangman’s fracture: A fracture through the pars of C2 that is usually the result of hyperextension injuries. These are unusual in children and are sometimes confused with congenital defects of the pars.
• Teardrop fracture: An avulsion fracture of the anterior (usually inferior) vertebral body. These fractures are stable if isolated but may occur in the context of multiple cervical spinal injuries.
• Cervical compression fracture: Axial loading injuries. Adjacent intervertebral disk injury is common. Spinal cord injury results from posteriorly displaced bone fragments or extruded disk material.
• Ligamentous injury without bony injury: A concern in children is the possibility of instability related to ligamentous injury without bony injury. Neck pain is common. Dynamic x-rays supplemented by MRI are used to establish the diagnosis.

Laboratory Tests

Standard preoperative laboratory tests: A CBC with platelet count, coagulation profile, serum electrolytes, and either a type and screen or type and cross in anticipation of the need for a blood transfusion are done.Normal findings are expected unless there is a history of polytrauma or pathological fracture.

Radiologic Tests

Radiological tests necessitating the use of ionizing radiation (x-ray and CT) should be used judiciously. Children who satisfy none of the NEXUS criteria can be considered at low risk for cervical spine injury and do not requiring imaging studies (56).

• NEXUS criteria
• Midline cervical spinal tenderness
• Evidence of intoxication
• Altered level of consciousness
• Focal neurological deficit
• History of a painful distracting injury

Plain x-rays

Cervical spine x-rays are indicated if the patient satisfies any one or more of the above criteria. Plain x-rays are not required in a child who has already satisfied criteria for a CT scan (see below).

• Cervical spine x-rays: Anteroposterior, lateral, and open-mouth or submental-vertex odontoid views are needed. In children <10 years of age, two views only are required (open mouth view can be omitted).
• Swimmer’s view x-ray:This view can be obtained if regular lateral x-ray does not visualize the superior articular surface of the T1 vertebral body.

CT scan

• Indications for CT scan of the cervical spine are as follows:
• GCS score <13 at initial assessment
• Patient has been intubated
• Plain x-rays technically inadequate
• Plain x-ray findings suspicious or definitely abnormal
• CT scan being done for other reasons: The patient is having other body areas scanned in the evaluation of head injury or multi-region trauma.
• Suspicion of cervical spine injury: The patient is alert and stable, but there is clinical suspicion of cervical injury based on dangerous mechanism of injury or focal neurological deficit, such as motor weakness or paresthesia in upper or lower limbs.

MRI

• MRI to assess neurological deficit: A MRI is done if there is or has been a neurological deficit, even if it resolves.

Findings in Radiological Assessment of Cervical Spine Injury

Injury	Plain X-ray Findings	CT Scan and MRI Findings
Atlanto-occipital dislocation	Odontoid malpositioned -Wackenheim line -Harris line -Powers ratio	CT -Condyle­C1 interval MRI -High signal intensity on T2- weighted MRI indicative of ligamentous injury. -Edema or hemorrhagic contusion within the spinal cord
Atlanto-axial subluxation	-ADI increased (5 or more mm) -PADI decreased (13 or less mm)	CT -Disruption of normal O-C1- C2 alignment on sagittal scanMRI -High signal intensity on T2- weighted MRI indicative of ligamentous injury. -Edema or hemorrhagic contusion in the spinal cord
Jefferson fracture	Rule of Spence	Two defects in the C1 ring
Odontoid fracture	-Angulation of the odontoid -Atlantoaxial subluxation	-Local swelling, hemorrhagic changes. -Widening of the C2 synchondrosis.
Hangman’s fracture	-Defect in the pars of C2 -Widened distance between posterior elements of C1 and C2	-Fractured pars interarticularis bilaterally
Teardrop fracture	-Anterior fragment and widened interspinous space -Angulation or narrowing of disk space	CT -Fracture line and teardrop fragmentMRI -Evidence of associated disk injury
Cervical compression fracture	-Loss of vertebral body height with or without angulation	CT -Canal compromise and cord compressionMRI -potential for disc disruption
Ligamentous injury without bony injury	Facet disruption, disk changes, or widened interspinous space	MRI with flexion/extension for soft tissue injury and instability.

Electrodiagnostic Tests

• Somatosensory evoked potentials (SSEPs) helpful in obtunded patients: Although rarely used, SSEPs may be helpful in clearing the cervical spine of obtunded patients or during flexion-extension x-rays.

Correlation of Tests

• Initial management based on initial assessment: If a cervical spine injury is confirmed or still suspected based on clinical assessment and radiological studies, then immobilization should be continued pending neurosurgical advice.