Trauma To The Vertebral Column

Question 1

After mechanical impact to the spinal cord, what are the primary and secondary injuries?

Answer 1

Primary: compression, contusion, laceration, traction

Secondary: Ischemia, Neuro inflammation, Excitotoxicity, Edema

Question 2

What forces does the vertebral body resist?

Answer 2

Bending and axial loading

Question 3

What normal forces do articular facets resist?

Answer 3

Resists all forces

Question 4

What normal forces do intervertebral discs resist?

Answer 4

Most important stabilizer against lateral and bending torsion

Question 5

Injuries to the vertebral column are most often at __points

Answer 5

Transition

Question 6

T/F: for deep pain perception you want them to try to bite us

Answer 6

T

Question 7

Until proven otherwise, all vertebral injuries are __

Answer 7

Unstable

Question 8

Schiff Sherrington posture

Answer 8

Extended forelimb posture with reduced reflexes as a result of severe thoracolumbar injury

Question 9

Prognosis for cervical vertebral injury if they survive the acute injury

Answer 9

60-70% have a good prognosis

Question 10

Prognosis for T3-L3 and L4-S2 vertebral injuries with intact pain perception

Answer 10

75-80% will have a good prognosis with surgery while about 60% have a good prognosis with conservative management

Question 11

Cervical or thoracolumbar vertebral injury with absent deep pain prognosis

Answer 11

Grave -> recommend euthanasia

Question 12

What should you give pets for pain control after assessing a vertebral injury?

Answer 12

Full mu - opioid agonist (morphine, oxymorphine, hydro morphine, methadone, fentanyl)

Question 13

What are the most common imaging modalities for vertebral injury?

Answer 13

1. Radiographs
2. CT
3. MRI

Question 14

T/F: radiographs are indicated in all cases of traumatic SCI and you should obtain ALL views in lateral recumbency

Answer 14

T, take laterals and use the horizontal beam to take ventrodorsal or take beam angled obliques

Question 15

The vertebrae have 3 compartments (dorsal, middle and ventral), how much disruption of these causes instability?

Answer 15

Disruption of 2/3 compartments = instability

Question 16

Severe >100% vertebral canal displacement =

Answer 16

Poor prognosis

Question 17

What would be some indications for CT or MRI of vertebral injuries?

Answer 17

• no obvious radiographs lesion
• radiographic lesion discordant with clinical localization
• surgical therapy is indicated base on clinical and/or radiographic signs
• evaluate integrity of spinal cord

Question 18

Stable vertebral injury Rx

Answer 18

Conservative treatment would include analgesics and cage rest for 6 weeks.

Question 19

Unstable vertebral injury conservative treatment indications

Answer 19

• majority of cervical fractures
• caudal lumbar or lumbar sacral fractures with minimal (grade 1-2) neurologic
• no significant concurrent injuries
• intact pain perception

Question 20

What is required for conservative management of vertebral injuries?

Answer 20

External coaptation

Question 21

External Coaptation

Answer 21

Must rigidity immobilize high motion segments above and below the level of the lesion with no attempts to reduce the fracture or luxation before or after putting on the brace

Question 22

External coaptation for cervical injury

Answer 22

Coaptation extends from behind eyes to behind scapulae

Question 23

T-L injury External Coaptation

Answer 23

Extends from cranial to scapulae to tail

Question 24

Lumbar injury external coaptation

Answer 24

Extends from cranial to scapulae to tail

Question 25

Briefly describe the timeline of conservative therapy

Answer 25

1. Hospitalize for 2-5 days (observe pain, neuro status, bladder, coaptation tolerance)
2. Recheck weekly for the next 3 weeks
3. Repeat radiographs at 4 weeks (remove coaptation when rads healing evident)

Question 26

Indications and goals for vertebral injury surgery

Answer 26

surgery is indicated if the injury is unstable with moderate to severe neurological signs. Surgery should reduce the malalignment and achieve rigid fixation +/- decompression of the spinal cord

Question 27

When would you want additional decompression of the spinal cord?

Answer 27

When imaging confirms the cord compression by: displaced fracture fragment, disc rupture, compressive hematoma, penetrating missile

Question 28

Advantages and Disadvantages of pins/screws and bone cement

Answer 28

Advantages:
- excellent strength against lateral bending and torsion
- easily adaptable configurations applicable in all anatomic areas
- positive profile pins preferred
- no need to remove implants

Disadvantages:
- low resistance to dorsoventral bending
- implant failure (bone pulls out)

Question 29

Cervical vertebral trauma has a __ mortality with surgery

Answer 29

High

Question 30

Thoracolumbar injuries indicate __ if unstable and have __ consequences if decompensation occurs

Answer 30

Surgery, severe

Question 31

Lumbosacral injuries considerations

Answer 31

• mobile lumbar spine +immobile sacrum = stress riser
• nerve roots of cauda equine more injury tolerant than spinal cord
• most morbidity associated with incontinence

Question 32

Sacrocaudal luxations

Answer 32

“Tail Pull injuries”

• common in cats
• trauma to S1- S3 segments/ cauda equina
• Clinical signs of plantigrade stance with paraparesis, weak, flaccid tail, decreased anal tone, urinary, fecal incontinence

Tx: cage rest, analgesics, bladder management or surgical tail amputation and/or variety of internal fixation

Question 33

Prognosis for sacrocaudal luxations

Answer 33

The most important indicator is presence of tail and perineal sensation. Most cats with absent sensation will have urinary function return which is good because the prognosis is poor for cats that don’t have perineal or tail sensation return for >30 days