Spine Topics Flashcards

1
Q

What % of pts with major spine injury will have second spine injury at another level?

A
  • 20%

- These pts often have simultaneous but unrelated injury (eg chest trauma)

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2
Q

Injuries directly associated with spinal cord injuries

A

-Arterial dissections (carotid and/or vertebral)

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3
Q

Def of Spinal Stability

A

Conceptual definition (from White and Punjabi): the ability of the spine under physiologic loads to limit displacement so as to prevent injury or irritation of the spinal cord and nerve roots (including cuada equina) and, to prevent incapacitating deformity or pain due to structural changes

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4
Q

Biomechanical stability

A

Ability of spine ex vivo to resist forces

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5
Q

Def of Level of Injury

A

Some disagreement here:

  • Lowest level of completely normal function, vs
  • Most caudal segment with motor function that is at least 3/5 and if pain and temp sensation is present
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6
Q

Incomplete lesion

A

Definition: any residual motor or sensory function more than 3 segments below the level of injury; look for signs of preserved long tract function
Signs of incomplete lesion:
-Sensation (including position sense) or voluntary movement in LEs
-Sacral sparing: preserved sensation around the anus, voluntary rectal sphincter contraction, or voluntary toe flexion
-Note, injury does NOT qualify as incomplete with preserved sacral reflexes alone

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7
Q

Types of incomplete lesions

A
  • Central cord syndrome
  • Brown-Sequard syndrome (cord hemisection)
  • Anterior cord syndrome
  • Posterior cord Syndrome
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8
Q

Complete Lesion

A

Def: no preservation of any motor and/or sensory function more than 3 segments below the level of injury

-Recovery is essentially zero if the spinal cord injury remains complete beyond 72 hrs

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9
Q

What % of pts with complete injury on initial exam will develop some recovery within 24 hrs

A

-Approx 3% of pts with complete injuries on initial exam will develop some recovery within 24 hours

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10
Q

Hemodynamic shock after SCI

A

Hypotension (usually SBP < 80) following SCI caused by variety of reasons

1) Inturruption of sympathetics (implies SCI above T1)
- Loss of vascular tone (vasoconstrictors) below the level of injury
- Leaves parasympathetics relatively unopposed causing bradycardia

2) Loss of muscle tone due to skeletal muscle paralysis below level of injury results in venous pooling and thus relative hypovolemia
3) Blood loss from associated wound may cause true hypovolemia

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11
Q

“Spinal Shock”

A

Description: transient loss of all neurologic function (including segmental and polysynaptic reflex activity and autonomic function) below level of SCI

  • Causes flaccid paralysis and areflexia lasting varying periods (usually 1-2 weeks, occasionally several months, sometimes permanent)
  • Resolution yields anticipated spasticity below the level of the lesion (a poor prognostic sign)
  • Spinal cord reflexes immediately above the injury may also be depressed on the basis of the Schiff-Sherrington phenomenon
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12
Q

Schiff-Sherrington Phenomenon

A
  • When the spinal cord is transected in the midthoracic region or a little lower, the stretch and other postural reflexes of the upper extremity become exaggerated; if the transection is made in the sacral cord, a similar effect is observed in the lower limbs
  • The effect is regarded as a release phenomenon, release from an inhibitory influence normally exerted by the spinal segments below the transection
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13
Q

Whiplash

A

Previously a lay term, but currently defined as:
-Traumatic injury to soft tissue structures in region of the c-spine (including cervical muscles, ligaments, intervertebral discs, facet joints) due to hyperflexion, hyperextension, or rotational injury to neck in the absence of fractures, dislocations, or intervertebral disc herniation
-The most common non-fatal automobile injury
S/Sx: may start immediately, but are most commonly delayed several hrs to days; include symptoms related to C-spine, headaches, cognitive impairment, and low back pain
Dx: use WAD classification system

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14
Q

Clinical Grading of WAD Severity

A

0: No complaints, no signs (not whiplash)
1: neck pain or stiffness or tenderness, no signs
2: above symptoms with reduced ROM or point tenderness
3: above symptoms with weakness, sensory deficit, or absent DTRs
4: above symptoms with fracture or dislocation (not whiplash)

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15
Q

Work up based on WAD

A

Grade 1: pt with normal mental status and physical exam do not require plain radiographs on presentation
Grade 2 & 3: C-spine x-rays, possibly with flexion/extension views; special imaging (CT, MRI, myelography) not indicated
Grade 3 & 4: should be managed as suspected SCI

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16
Q

Treatment based on WAD

A

Note: whiplash is usually a benign condition requiring little treatment and resolves in days to a few weeks in most cases

1) ROM exercises: start immediately for all grades
2) Encourage early return to activities: immediately for grade 1; ASAP for grades 2 and 3
3) Cervical collars and rest: not for grade 1; not for > 72 hrs for grade 2; not for > 96 hrs for grade 3
4) Passive modality therapies (heat, ice, massage, TENS, US, relaxation techniques, acupuncture, and work alteration): not for grade 1; optional if symptoms last > 3 wks for grade 2 and 3
5) Medications (optional use of NSAIDs and non-narcotic analgesics recommended for < 3 wks): not for grade 1; ok for grade 2; ok for grade 3 and occasional narcotics may also be needed
6) Surgery: not for grade 1 or 2; only indicated in grade 3 if there is progressive neurologic deficit or persisting arm pain

*Note, the following are NOT recommended: cervical pillows and soft collars, bed rest, spray and stretch exercises, muscle relaxant medications, TENS, reflexology, magnetic necklaces, herbal remedies, homeopathy, OTC medications (except NSAIDs), intraarticular, intrathecal, or trigger point steroid injections

17
Q

Outcome of whiplash injury

A
  • Study done in Switzerland (all medical costs paid for by state, no opportunity for litigation, no compensation for pain and suffering, although the possibility of permanent disability), 117 pts, < 56 yrs old:
  • 3 months: 56% recovered
  • 6 months: 70% recovered
  • 12 months: 76% recovered
  • 24 months: 82% recovered

At 2 years, there were 21 pts with continued symptoms, of these:

  • Only 5 were restricted with respect to work (3 reduced time, 2 on disability)
  • Pts were older and had more varied complaints on initial exam
  • Had more rotated or inclined head positions at time of impact
  • Had higher incidence of pretraumatic headaches
  • Had higher incidence of certain pre-existing findings (radiologic evidence of cervical osteroarthritis)

Factors which had no impact on outcome:

  • Speed of cars
  • Gender
  • Vocation
  • Psychological factors
18
Q

Overview of Peds Spine Injury

A
  • Spinal cord injury fairly uncommon in kids secondary to ligamentous laxity, high head to body weight ratio, immaturity of paraspinous muscles and underdeveloped uncinate process; these tend to involve ligamentous rather than bony injuries
  • Ratio of head injury to spinal cord injury in kids is 30:1
  • Only 5% of spinal cord injury occurs in kids
  • Most vulnerable spinal segment in kids: C-spine (subaxial injuries are fairly uncommon)
  • C-spine injury: 42%
  • Thoracic: 31%
  • Lumbar: 27%
  • Fatality rate higher with peds than with adults (opposite to trend with head injury)
  • Cause of death is more often related to other severe injuries rather than the spinal cord injury
19
Q

Practice guidelines in Peds C-Spine Injury: Dx and Tx

A

Diagnosis:
Level II: C-spine x-rays are NOT indicated in Peds trauma pts who are:
-Alert and conversant
-Neurologically intact
-Without posterior midline cervical tenderness (with no distracting pain)
-And who are not intoxicated
Level III: management for Peds trauma pts who are nonconversant or have AMS, neuro deficit, neck pain, or painful distracting injury, are intoxicated, or have unexplained hypotension:
-Pts < 9 yrs old: AP and lateral C-spine X-rays
-Pts ≥ 9 yrs old: open-mouth odontoid view in addition to the above
-Supplement these x-rays with thin cut CT through areas of suspicion of areas not visualized on plain x-ray
-Flexion/extension C-spine x-rays or fluoroscopy may be considered to R/O ligamentous instability if there is still suspicion of instability after the above x-rays are obtained
-Consider: C-spine MRI to R/O cord or nerve root compression, evaluate ligamentous integrity, or provide info for neurologic prognosis

Treatment
Level III
-Kids < 8 yrs old: immobilize with thoracic elevation or an occipital recess (allows more neutral alignment due to relatively large head)
-Kids < 7 yrs old with injury of the C2 dentocentral synchondrosis: closed reduction and halo immobilization
-Consider: primary operative treatment for isolated C-spine ligamentous injuries with associated deformity

20
Q

Peds C-spine synchondroses

A
  • Normal synchondroses can be mistaken for fractures (esp dentocentral synchondroses of axis which may be mistaken for odontoid fracture)
  • Actual fractures can occur through synchondroses
  • Recommended Tx for fractures through the synchondroses: emergency reduction followed by external immobilization (given tendency for synchondroses to fuse); internal immobilization/fusion should be reserved for persistent instability
21
Q

Pseudospread of the Atlas

A

Definition: > 2 mm total overlap of two C1 lateral masses on C2 on AP open-mouth view; present in most kids 3 months-4 yrs of age

  • Prevalence: 91-100% in second year of life
  • Normal total offset is typically 2 mm during 1st year, 4 mm during 2nd year, 6 mm during 3rd year, and decreasing thereafter (maximum is 8 mm)
  • Trauma is NOT a contributing factor
  • Probably due to disproportionate growth of atlas on axis
  • May be misdiagnosed as Jefferson fracture which rarely occurs prior to teen-age years (due to lower weight of kids, more flexible neck, increased plasticity of skull, and shock absorbing synchondroses of C1)
  • Neck rotation can sometimes simulate appearance of Jefferson fracture
  • When suspicion of fracture is high: CT scan through C1 can resolve the issue of whether or not there is a fracture
22
Q

Pseudosubluxation

A

Description: either anterior displacement of C2 on C3 and/or significant angulation at this level

  • Seen in kids up to age 10 on lateral C-spine x-ray after trauma
  • Flexion/Extension is centered at C2-3 in kids up to 10 yrs old, and this moves down to C4-5 or C5-6 after age 10; thus, C2 normally moves anteriorly on C3 up to 2-3 mm in peds
  • When head is flexed, displacement is EXPECTED, may be exacerbated by spasm, but does NOT represent pathological instability
  • Fractures and dislocations are unusual in kids and when they do occur, they resemble those in adults

Treatment recommendation: treat pt for soft-tissue injury and not for subluxation

23
Q

Clinical Criteria for Cervical Spine Stability

A
  1. Awake, alert, oriented (no mental status changes, including no alcohol or drug intoxication)
  2. No neck pain (with no distracting pain)
  3. No neurologic deficits

Note: to date, there has not been a case of significant occult C-spine injury in trauma pt who met all of the criteria above

24
Q

Practice Guideline for Assessment of SCI in Hospital

A

Clinical Assessment
-Level III: the ASIA international standards for neurologic and functional assessment of SCI is recommended

Functional Outcome Assessment

  • Level II: the Functional Impairment Measure (FIM) is recommended
  • Level III: the modified Barthel index is recommended
25
Q

Practice Guideline for in hospital critical care management of SCI

A

Level III: monitor pts with acute SCI (esp those with severe cervical level injuries) in ICU
Level III: cardiac, hemodynamic, and respiratory monitoring after acute SCI is recommended
Level III: hypotension (SBP < 90) should be avoided or corrected ASAP
Level III: maintain MAP at 85-90 mm Hg for first 7 days after SCI to improve spinal cord perfusion

26
Q

Pressor of choice in SCI

A

-Dopamine

Note: AVOID phenylephrine: non-inotropic and possible reflex increase in vagal tone with bradycardia

27
Q

Drug to give if there is bradycardia associated with hypotension in SCI

A

Atropine

28
Q

Benefits of early C-collar removal

A
  • Reduction of skin breakdown
  • Fewer days of mechanical ventilation
  • Shorter ICU stays
  • Reduction of ICP
29
Q

Methylprednisolone in SCI Practice Guidelines

A

Note: highly controversial
Level III: tx for 24-48 hrs after SCI as option should be undertaken only with the knowledge that evidence suggesting harmful side effects is more consistent than any demonstrated clinical benefit

Argument for: beneficial sensory and motor effects seen at 6 wks, 6 months, and 1 yr (for both complete and incomplete) injuries when given WITHIN 8 hrs (outcome possibly worse at 1 year if started after 8 hrs from injury)

Exclusion criteria for study:

1) Cauda equina syndrome
2) GSW to spine (retrospective study showed no benefit and increased risk of complications with steroids with GSW)
3) Life-threatening morbidity
4) Pregnancy
5) Narcotic addiction
6) Age < 13
7) Pt on maintenance steroids

30
Q

Critique of using methylprednisolone in SCI

A

1) Metaanalysis could not find any study that replicated original studies
2) At 1 yr, only slight sensory advantage
3) High-dose MP may cause acute corticosteroid myopathy (ACM) which might indicate that some pts that improved after MP were actually recovering from their ACM
4) ACM related complications: prolonged ventilator dependency
5) Other complications of steroids: hyperglycemia, pneumonia, sepsis

31
Q

Administration of methylprednisolone in SCI

A
  1. Conc is 62.5 mg/ml
  2. Bolus 30 mg/kg initial IV bolus over 15 min with an IV controller (this gives 0.48 ml/kg of solution in 15 min)
    bolus rate (ml/hr) = pts weight (kg) X 1.92 (for 15 min)
  3. Follow with 45 min pause
4. Maintenance infusion: 5.4 mg/kg/hr continuous infusion as shown (and maintain during any necessary surgery if possible)
maintenance rate (ml/hr) = pts weight (kg) X 0.0864 (for 23 OR 47 hrs)

Duration: when therapy initiated within 3 hrs after injury, give maintenance for 23 hrs; when therapy initiated between 3-8 hrs after injury, may be incremental benefit to giving maintenance for 47 hrs, with slightly higher risk of infection and pneumonia