S21C255 - Spine and Spinal Cord Trauma Flashcards Preview

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Flashcards in S21C255 - Spine and Spinal Cord Trauma Deck (57)
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1
Q

Vertebral Anatomy

A
  • each vertebra has an anterior body and posterior arch
  • arch is composed of 2 pedicles, 2 laminae, and 7 processes (one spinous, 2 transverse, 4 articular)
  • odontoid = dens
2
Q

Spinal stability

A
  • 3 columns in the Denis system are used to classify injuries as stable or not
  • columns: anterior, middle, posterior
  • anterior column: consists of anterior vertebral body, anterior annulus fibrosus, anterior longitudinal ligament
  • middle column: formed by posterior wall of vertebral body, posterior annulus fibrosus, posterior longitudinal ligament
  • posterior column: bony complex of posterior vertebral arch and posterior ligamentous complex
  • unstable injury = disruption of 2 or more columns plus vertebral body compression (>25% for 3-7th vertebrae or >50% for thoracic and lumbar vertebrae)
  • can have unstable injury w/o bony injury (ligamentous), and therefore should do a flexion-extension xr or MRI
3
Q

Mechanism of Injury and cervical fractures associated

A

Flexion: b/l interfacetal dislocation (U), simple wedge #, clay-shoveler’s #, flexion teardrop # (U)

Flexion-rotation: unilateral interfacetal dislocation

Pillar #: # of lateral mass

Vertical Compression: jerfferson burst # of atlas, other burst # (U)

Hyperextension: hyperextension dislocation (U), avulsion # of anterior arch of atlas, extension teardrop # (U), # of posterior arch of atlas, laminar #, hangman’s # (U)

Lateral flexion: uncinate process #

Other #: dens # (U), occipital condyle # (U), occipitoatlantal dissociation (U)
U= unstable

4
Q

Occipital Condyle #

A
  • assoc with high-velocity injury
  • type 1: comminuted
  • type II: extension of a linear basilar skull #
  • type III: avulsion of a fragment
  • usually need CT for dx
  • neurological impairment is common
5
Q

Occipitoatlantal dissociation

A
  • skull displaced anteriorly or posteriorly or distracted from the cervical spine
  • often fatal
  • distance b/w the basion and the superior cortex of the dens should normally be
6
Q

C1 Atlas #: jefferson

A

Jefferson #:

  • usual MOI is axial load
  • occipital condyles are forced downward and produce a burst # by driving the lateral masses of C1 apart
  • can see outward displacement of th elateral masses on the open-mouth odontoid xr
  • if displacement of both lateral masses is >7mm when combined, rupture of the transveres ligament is likely and thus an unstable injury
7
Q

C1 Atlas #: transverse ligament disruption

A
  • runs along posterior surface of the dens
  • crucial to maintaining stability of the 1st/2nd vertebrae
  • w/o a # present one must examine the atlantodens interval (predental space), space b/w posterior aspect of the anterior arch of C1 and the dens , normal is 5mm AD interval indicates damage to the transverse ligament
8
Q

C1 Atlas #: avulsion # of the anterior arch of the atlas

A
  • hyperextension MOI, avulse the inferior pole of anterior tubercle of C1
  • presence of perivertebral soft tissue swelling
  • stable
9
Q

C1 Atlas #: # of the posterior arch of the atlas

A
  • MOI: hyperextension

- isolated # of the posterior arch of the atlas is stable

10
Q

C2 axis #: odontoid #

A
  • MOI: significant external forces
  • immediate, severe neck pain
  • neurologic abnormality in 25% of cases (minor to quad)
  • type I: avulsion of the tip, stable
  • type II: jxn of odontoid with body of C2 (most common)(unstable)
  • type III: through the superior portion of C2 at the base of the dens (unstable)
11
Q

C2 axis #: Hangman’s # (traumatic spondylolisthesis of the axis)

A
  • # of both pedicles of C2 which allows the body of C2 to displace anteriorly on C3
  • extension mechanism
  • may be neurologically intact
12
Q

C3-7 #

A
  • teardrop # - unstable

- loss of >25% of the vertebral body height suggest instability

13
Q

C3-7 #: Anterior subluxation

A
  • AKA hyperflexion sprain
  • ligamentous failure of interspinous or posterior longitudinal ligament
  • no #, therefore look for anterior soft tissue swelling, widening of the spinous processes and posterior widening of the intervertebral space
  • cervical disk spaces should have a variation in alignment of
14
Q

C3-7 #: simple wedge #

A
  • compression b/w 2 other vertebral bodies causes a wedge #
  • usually the superior end plate #, not the inferior
  • if isolated, then stable
  • if significant posterior ligamentous injury assoc, may be unstable
  • simple wedge is differentiated from burst # by absence of a vertical # of the vertebral body
15
Q

C3-7 #: flexion teardrop #

A
  • extreme flexio = MOI
  • ‘teardrop’ is the anteroinferior portion of the vertebral body that is separated and displaced from the remaining portion of the vertebral body
  • complete disruption of the ligaments
  • assoc with anterior spinal cord syndrome
  • highly unstable
16
Q

C3-7 #: spinous process avulsion = clay-shoveler’s #

A
  • avulsion of the end of a lower cervical spinous process (often C7)
  • from hyper-flexion
  • if isolate, then stable
17
Q

C3-7 #: unilateral interfacetal dislocation

A
  • MOI : flexion and rotation
  • articular mass and inferior facet on one side of vertebra is anteriorly dislocated
  • vertebral body will be diplaced
18
Q

C3-7 #: bilateral inerfacetal dislocation

A
  • MOI: hyperflexion
  • disruption of all ligamentous structures allows articular masses of one vertebra to dislaocate superior and anteriorly into the intervertebral foramen of the vertebra below
  • dislocated anteriorly at least 50% of its width
  • neuro deficits
  • unstable
19
Q

C3-7 #: pillar or pedicolaminar #

A
  • isolated vertical or oblique # through the lateral mass
  • lamina and pedicle remain intact
  • MOI: extension and rotation
  • stability depends on degree of ligamentous damage
20
Q

C3-7 #: burst #

A
  • MOI: direct axial load
  • verticle # through the vertebral body and widening of th eunterpedicular distance on anterior radiograph
  • unstable
21
Q

C3-7 #: Hyperextension dislocation

A
  • tear of anterior longitudinal lig and intravertebral disk and disruption of the posterior ligamentous complex
  • present with facial trauma and central cord syndrome
  • diffuse prevertebral soft tissue swelling
  • injury is usually reduced by the c-collar
  • anterior disk space widening, # of anteroinferior end plate of the body
  • unstable
22
Q

C3-7 #: Extension teardrop #

A
  • hyperextension may cause the anterior longitudinal lig to avulse a fragment off the anteroinferior corner of the vertebral body
  • usually in elderly
  • unstable
23
Q

C3-7 #: laminar #

A
  • moi: hyperextension
  • may be assoc with spinous process #
  • usually require CT for dx
24
Q

C3-7 #: uncinate process #

A
  • lateral superior edges of the vertebral body form b/l ridges called uncinate processes found on C3-T1
  • extreme lateral flexion may cause a transverse # at the base of the uncinate process
  • usually have ipsilateral neuro deficits
  • stable if isolated
25
Q

Thoracic spine

A
  • very strong and stable and reinforced by ribs so takes a very high force to injure the thoracic spine
  • small spinal canal so if injured there is a high risk of cord injury
26
Q

Lumbar spine

A
  • rare to get cord injury

- more mobile

27
Q

Thoracic and Lumbar Spine Fractures: compression #

A
  • MOI: axial loading and flexion
  • failure of anterior column
  • middle column remains intact
  • stable unless loss of height is >50% of vertebral body ht
  • unlikely to have neuro damage
28
Q

Thoracic and Lumbar Spine Fractures: burst #

A
  • MOI: axial load
  • anterior and middle columns fail
  • retropulsion of bone and fragments into canal, may cause spinal cord compression
  • unstable
29
Q

Thoracic and Lumbar Spine Fractures: flexion-distraction injuries

A

-seat-belt injuries (lap belts)
-failure of posterior and middle columns
-intact anterior column prevents subluxation
-opening of posterior disk space
0unstable
-variant = Chance #

30
Q

Thoracic and Lumbar Spine Fractures: # dislocations

A
  • compression, flexion, distraction, raotatio or shearing forces
  • failure of all 3 columns
  • subluxation or dislocation
  • very unstable
31
Q

Sacrum and Coccyx #

A
  • coccyx = 4 bones fused together
  • assoc with # of pelvis
  • transverse # through body may cause injury to the cauda equina
  • sacral # may produce bowel/bladder dysfxn
  • dx of coccygeal injury is done by rectal exam and pain with motion of the coccyx, imaging not needed, tx is symptomatic and doughnut pillow
32
Q

Complete spinal cord lesion

A

-absence of sensory and motor below the level of the injury

33
Q

Spinal shock

A
  • pts lose all reflex activities below the area of injury

- lesions cannot be deemed complete until spinal shock resolved

34
Q

Spinal cord tracts

A
  • corticospinal tract: descending motor neurons, 90% cross at lower medulla, damage to this tract results in ipsilateral weakness, spasticity, increased DTR, and babinski sign
  • spinothalamic tracts: ascending sensory tracts, transmits pain and temperature, ascend 1-2 levels before entering dorsal grey matter of SC where they synapse on a 2nd neuron that crosses the midline in the anterior commissure and ascneds, when damaged the pt has contralateral loss of pain and temperature sensation
  • dorsal (posterior) columns: sensory afferent ascending tracts, transmit vibration and proprioceptive info, enter ipsilateral side and do not cross until they ascend to the medulla, injury results in ipsilateral loss of vibration and position sense
  • light touch is transmitted by spinothalamic and dorsal tracts therefore light touch is not lost unless both tracts are affected
35
Q

C-spine neurons

A
  • there are 8 c-spine roots for 7 vertebrae
  • exit through intervertebral foramen above their corresponding vertebral body
  • spinal nerve exiting below C7 is C8 and all subsequent nerve roots starting with T1 exit below their vertebral body
36
Q

Anterior Cord Syndrome

A
  • damage to corticospinal and spinothalamic pathways
  • posterior column intact
  • loss of motor fxn and pain/temperature sensation distal to the lesion
  • vibration, position and crude touch preserved
  • can results from trauma or thrombosis (ischemic injury) or mass effect
  • poor prognosis
37
Q

Central Cord Syndrome

A
  • often older pts with pre-existing cervical spondylosis with hyperextension injury
  • central fibers of corticospinal and spinothalamic tracts affected
  • tracts providing fxn to upper extremities are more medial , lower extremity tracts are more lateral
  • good prognosisi for recovery of fxn however may not regain fine motot control
  • decreased strength, pain, temperature sensation, upper»lower
  • most maintain bowel and bladder control
38
Q

Brown-sequard syndrome

A
  • hemisection of the cord
  • ipsilateral loss of motor fxn, proprioception and vibratory sensation
  • contralateral loss of pain and temperature sensation
  • often penetrating injury, or can be caused by lateral cord compression secondary to disc protrusion, hematomas, bone injury, tumor
  • best prognosis for recovery
39
Q

Cauda Equina Syndrome

A
  • cauda equina = lumbar, sacral, coccygeal nerve roots
  • variable motor and sensory loss in lower extremitites, sciatica, bowel and bladder dysfxn, saddle anesthesia (loss of pain sensation over the perineum)
  • prognosis good b/c involves peripheral nerves and these regenerate better
40
Q

Neurogenic Shock

A
  • injury to SC at level of cervical or thoracic vertebrae causes peripheral sympathetic denervation
  • loss os sympathetic tone causes decr SVR, decr BP
  • damage of T1-T4 means loss of sympathetic tone to heart, vagus nerve is unopposed, causing bradycardia, absence of reflex tachycardia
  • usually warm, peripherally vasodilated, hypotensive and often bradycardic
  • r/o hemorrhage as reason for shock first!!
  • tx: fluid resusc for MAP of >85 (minimize secondary cord injury), may require inotropic pressors to improve CO and raise perfusion pressure, if significant brady give atropine, may require pacemaker
41
Q

Spinal Shock

A
  • refers to temporary loss or depression of spinal reflex activity that occurs below a complete or incomplete spinal cord injury
  • bulbocavernosus reflex is among the first to return as spinal shock resolves
  • often persists for days to weeks
42
Q

Care for pts with Spinal Injury

A
  • any pt with injury above C5 should have airway secured
  • perform neuro assessment before intubation/sedation
  • if low BP, presume hemorrhagic shock first, neurogenic shock is a diagnosis of exclusion
  • do a detailed neuro exam
  • urinaryor fecal incontinence or priapism places the pt at high risk of SCI
  • sacral sparing with preservation of the reflexes denotes an incomplete spinal cord level lesion
43
Q

Bulbocarvernosus reflex

A

-squeeze the penis while simultaneously checking to see if the anal sphincter contracts

44
Q

Cremesteric reflex

A

-if the scrotum rises there is some spinal cord integrity remaining

45
Q

Anal wink reflex

A

-contraction of the anal musculature when tested with pin prick sensation

46
Q

priapism implies a complete SCI

A

-

47
Q

C-spine imaging

A
  • there is an incidence of 2-5% c-spine injuries related to blunt head trauma but 9% incidence if significant head injury present
  • if one cannot see all 7 vertebral bodies on the lateral then order a swimmer’s view
  • lateral can identify 90% of injuries to bones and ligaments
  • if one # seen, do further imaging as 10% of pts with a spinal # will have a second
48
Q

Flex-ex films

A
  • flexion-extension
  • assess spinal column stability in pts with normal xr and pain/tenderness
  • step-off of >3.7mm or angulation >11 denotes cervical spine instability
  • although can still have normal flex-ex xr and have ligamentous disruption
49
Q

Myotomes:

A

C5/6: deltoid, biceps - arm aduction, elbow flexion
C6/7: extensor carpi radialis - wrist extension
C7/8: triceps - elbow extension
C8/T1: hand intrinsics - finger abduction
-flexor digitorum profundus - hand grasp

T2-T7: chest muscles
T9-T12: abdominal muscles

L1/2/3: iliopsoas - hip flexion
L2/3/4: quadriceps - knee extension
L4/5, S1/2: knee flexion - hamstrings
L4/5: tibialis anterior - ankle dorsiflexion
L5/S1: ext hallucis longus - great toe extension

S1/2: gastrocnemius - ankle plantar flexion
S2/3/4: bladder and anal sphincter - voluntary rectal tone

50
Q

Motor grading system:

A

0 - no active contraction
1 - trace visible or palpable contraction
2 - movement with gravity eliminated
3 - movement against gravity
4 - movement against gravity plus resistance
5 - normal power

51
Q

NEXUS c-spine

A

Imaging is unnecessary if the pt meets 5 criteria:

  1. absence of midline cervical tenderness
  2. normal level of alertness and consciousness
  3. no evidence of intoxication
  4. absence of focal neurological deficit
  5. absence of painful distracting injury
52
Q

Canadian C-spine rule

A

Imaging is unnecessary if pt meets 3 criteria:
1. no high-risk factors (age >65, presence of paresthesias in the extremities, a dangerous mechanism of injury (fall from ht >3 ft, axial loading injury, high-speed MVC, rollover, ejection, ATV, bicycle collision)

  1. there are low-risk factors that allow for a safe aassessment of ROM (low-risk factors: simple rear-end MVC, pt able to sit up in ED, pt ambulatory at any time, delayed onset of neck pain, absence of midline cervical tenderness)
  2. pt is able to actively rotate his/her neck (can rotate 45 deg to the left and to the right)
53
Q

mgmt

A
  • move off hardboard asap, hospital bed provides enough support
  • move using spinal immobilization
54
Q

Treatment of Spinal Injuries

A
  • penetrating spinal trauma: prophylactically treat with Abx
  • progressive neurologic deficits should have surgical intervention
  • bellet removal not necessary from cervical/thoracic but does improve outcome if removed from T11-L2
55
Q

Pediatric Spine and SCI

A
  • 10yo similar to adult injuries
  • multi-level injuries more common in children
  • odontoid # are most common c-spine injury in children
  • important to asses thoracic and lumbar spines as these are injuries that are often missed

-acquired torticollis, wry neck, treat with mild analgesics or low-dose benzo

56
Q

SCIWORA

A
  • lack of evidence of vertebral fracture on plain xr and CT in pt with a SCI
  • more common in younger children
  • occurs in 55% of thoracolumbar injuries in the peds popn
  • MRI to diagnose
  • neurologic damage usually apparrent w/in 48h
  • numbness/paresthesias/shock-like sensations/ transient quadriparesis (stinger)
57
Q

Normal pediatric variants of c-spine

A
  • absence of lordosis in 14% of children
  • pseudospread of atlas on the axis up to 7yo
  • anterior wedging of vertebral bodies up to 3mm
  • over-riding of anterior arch of C1 above odontoid up to 20% of children
  • pseudosubluxation - C2-C4, disrupts anterior/psoterior lines, spinous processes should still form a straight line, any offset suggests unilateral facet dislocation