C-Spinal Injury and Diagnosis

Approach to C-spine x-rays

3-view C-spine series is the screening modality of choice:

1.     Lateral C1~T1 +/- swimmer’s view

a.     Lateral view is best; it identifies 90~95% of injuries

2.     Odontoid view (open mouth or oblique submental view)

a.     Examine the dens for fractures

                                               i.     If unable to rule out fracture, repeat view or consider CT or plain film tomography

b.     Examine lateral aspects of C1 and spacing relative to C2

3.     AP view

a.     Alignment of spinous processes in the midline

b.     Spacing of spinous processes should be equal

c.      Check vertebral bodies and facet dislocations

Normal Swimmer’s view x-ray

The ABCS of lateral view

A—adequacy and alignment

·      Must see C1~T1 junction; if not, downward traction of shoulders, swimmer’s view, bilateral supine oblique, or CT scan are needed.

·      Lines of contour in children < 8 yr of age, can see physiologic subluxation of C2 on C3, and C3 on C4, but the spino-laminal line is maintained.

·      Fanning of spinous processes suggests posterior ligamentous disruption

·      Widening of facet joints

·      Check atlanto-occipital joint

·      Line extending inferiorly from clivus should transect odontoid (Wackenheim or clivus-canal line)

·      Atlanto-axial articulation, widening of predental space (normal: < 3mm in adults; < 5mm in children) indicates injury of C1 or C2

B—bones

·      Height, width, and shape of each vertebral body

·      Pedicles, facets, and laminae should appear as one—doubling suggests rotation

C—cartilage

·      Intervertebral disc spaces—wedging anteriorly or posteriorly suggests vertebral compression

S—soft tissue

·      Widening of retropharyngeal space (normal: < 7 mm at C1~C4; may be wide in children < 2yrs. on expiration) or retrotracheal spaces (normal: < 22mm at C6~T1; < 14mm in children < 5yrs.)

Supine oblique views, though rarely used, are better visualization of posterior element fractures (lamina, pedicle, facet joint) and is good for assessing the patency of neural foramina; it can also be used to visualize the C7~T1 junction.

Sequelae of C-spine fractures:

·      Acute phase of spinal cord injury

o   Spinal shock—absence of all voluntary and reflex activity below level of injury

§  Decreased reflexes, no sensation, flaccid paralysis below level of injury, lasting days to months

o   Neurogenic shock—loss of vasomotor tone, SNS tone

§  Watch for hypotension (lacking SNS), bradycardia (unopposed PNS), and poikilothermia (inability to maintain constant core temperature due to lacking SNS so no shunting of blood from extremities to core).

§  Occurs within 30min of spinal cord injury at level T6 or above, lasting up to 6 weeks

§  Provide airway support, fluids, atropine (for bradycardia), vasopressors for BP support

·      Chronic phase

o   Autonomic dysreflexia—in patients with a spinal cord injury at level T6 or above

§  Symptoms and signs include pounding headache, nasal congestion, feeling of apprehension or anxiety, visual changes, dangerously increased blood pressure. (Think opposite of neurogenic shock!)

§  Common triggers

·      GU causes—bladder distention, UTI, kidney stones

·      GI causes—fecal impaction or bowel distention

§  Treatment—monitoring and controlling blood pressure, prior to addressing causative issue

20% of C-spine fractures are accompanied by other spinal fractures so ensure thoracic and lumbar spinal x-rays are normal before proceeding to operating theatre.

Spinal and Spinal Cord Injuries

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For patients presenting after significant fall (> 12ft), deceleration injuries, blunt trauma to head, neck, or back, assume cord injury. Spinal immobilization such as spinal collar and transportation via spine board is to be undertaken until spinal injury can be ruled out. Sometimes vertebral injuries can be sustained without spinal cord injury, and a normal neurologic exam does not rule out spinal injury. Sometimes the spinal cord can be injured despite normal C-spine x-ray (SCIWORA = spinal cord injury without radiologic abnormality). The injuries can include complete/incomplete transection, cord edema, and spinal shock.

Any spinal cord injury below T10 à beware Cauda Equina Syndrome! Symptoms include incontinence, anterior thigh pain, quadriceps weakness, abnormal sacral sensation, decreased rectal tone, and variable reflexes.

History:

·      Mechanism of injury

·      Previous deficits

·      Neck pain, weakness/paralysis, paresthesia

Physical exam:

·      Vital signs

·      Abdominal: ecchymosis, tenderness

·      Complete neurological examination, including mental status

·      Spine:

o   Front—palpate C-spine while maintaining neutral position

o   Back—log roll to palpate T and L-spine and assess rectal tone

o   When palpating, assess for tenderness, muscle spasm, bony deformities, step-off, and spinous process mal-alignment.

·      Extremities: capillary return, suspect thoracolumbar injury with calcaneal fractures (e.g. patient falling from height landing on his/her feet).

Investigation:

·      Blood work: CBC, electrolytes, creatinine, glucose, coagulation profile, cross and type, and toxicology screen.

·      Imaging

o   C-spine x-ray series (AP, lateral, odontoid)

o   Thoracolumbar x-ray series (AP, lateral) if any of the following is present:

§  C-spine injury

§  Unconscious patient (and probable mechanism of injury)

§  Patients with neurological symptoms or findings

§  Patients with palpable deformities when log rolled

§  Patients with back pain

§  Patients with bilateral calcaneal fractures (concurrent burst fractures of the thoracic or lumbar spine T11~L2 will be find in 10%)

o   Consider CT for subtle bone injuries

o   Consider MRI for soft tissue injuries

C-Spine can be cleared when:

·      Oriented to person, place, time, and event

·      No intoxication

·      No posterior midline cervical tenderness

·      No focal neurological deficits

·      No painful distracting injuries (so that patient neglects to recognize pain from neck).

Management of cord injury

·      Immobilize

·      DRABC

·      Treat neurogenic/spinal shock (maintain systolic BP > 100)

·      NG tube and Foley catheter

·      High dose steroids (methylprednisolone 30mg/kg bolus, then 5.4mg/kg/h drip within 6~8 h after injury) is controversial and recently has less support

·      Complete imaging of spine and consult spine service if available

·      Continually assess high cord injuries as edema can travel up cord

·      If there is cervical cord injury, watch out for respiratory insufficiency

o   Low cervical transection (C5~T1) produces abdominal breathing (phrenic innervation of diaphragm still intact).

o   High cervical injury (C4 and above) may require intubation and ventilation

·      Supportive treatment: warm blanket, Trendelenburg position (the body is laid supine with the feet higher than the head by 15-30 degrees), volume infusion, consider vasopressors.