Vertebral Trauma

Question 1

What are the common etiologies resulting in vertebral trauma?

Answer 1

Motor vehicle accidents, falls, animal-animal encounters, malicious abuse, penetrating missiles

Question 2

What are the different types of vertebral column injuries?

Answer 2

Fracture/luxation, acute disc herniation, soft tissue injury, contusion/laceration, nerve root injury/entrapment

Question 3

What are the normal forces acting on the axial skeleton?

Answer 3

Bending (dorsoventral and lateral), torsional, shear, axial loading (compression, tension)

Question 4

What forces do the vertebral body, articular facets, and intervertebral discs resist the most?

Answer 4

Vertebral body-bending and axial loading
Articular facets-all forces
intervertebral disc- most important stabilizer against lateral bending and torsion

Question 5

What causes fractures of the vertebral columns?

Answer 5

Excessive biomechanical forces applied

Question 6

What are the stress riser regions of the spine where injuries are more common?

Answer 6

Areas where there is a sharp change in the structure of the vertebrae
-cranio-cervical junction
-cervical-thoracic junction
-T-L junction
-L-S junction

Question 7

What should be your primary goal when performing an exam of a patient with a potential back injury?

Answer 7

Do not make things worse! Establish the severity of neurologic signs and determine what other injuries are present or need further investigation

Question 8

What should be the first thing done for treatment in back injury cases?

Answer 8

Emergency ABCs!

Question 9

What concurrent injuries are common in vertebral trauma cases?

Answer 9

Cardiothoracic injury, appendicular fractures, soft-tissue trauma, head injury, UTIs

Question 10

How should you perform a neuro exam in back patients?

Answer 10

Perform with animal immobilized in lateral recumbency
-assess mentation, body posture, cranial nerves
-look for voluntary motor movement (hard to do when in lateral)
-test all reflexes and dont forget the tail!
-ASSESS FOR DEEP PAIN!! (head movement during withdrawal)

Question 11

T/F: until proven otherwise, assume all injuries are stable

Answer 11

FALSE- should assume all are unstable

Question 11

Would a patient with a modified frankel score of 4 have deep pain intact?

Answer 11

Yes- only 5 has deep pain absent

Question 12

What would a MFS of 1 indicate?

Answer 12

The animal is in pain

Question 13

Why might spinal shock lead you to an incorrect localization during your neurologic exam of a patient?

Answer 13

It causes you to see decreased reflexes to the pelvic limbs, even while the lesion may be cervical

Question 14

What is the prognosis in a cervical injury case if they survive the acute injury?

Answer 14

60-70%

Question 15

What is the prognosis for a cervical or thoracolumbar injury where deep pain is no longer present?

Answer 15

Grave to hopeless
-generally recommend euthanasia

Question 16

What is the prognosis for T3-L3 and L4-S2 injuries with intact pain perception?

Answer 16

75-80% have a good prognosis with surgery

Question 17

What is the best way to immobilize a back dog for treatment?

Answer 17

Use whatever you have! Plywood, cardboard, stretcher, gurney, cage door, tape, cloth
- be sure to check that what you use does not interfere with the animals ventilation

Question 18

What supportive care is indicated with back animals?

Answer 18

Maintaining perfusion to injured tissues (oxygen therapy, fluids), analgesics

Question 19

What analgesics should you use for back animals?

Answer 19

Treat pain as soon as patient is stable
-full mu-opioids are usually indicated, and you can combine with NSAIDs and sedatives/anxiolytics

Question 20

What should you avoid when imaging back patients?

Answer 20

Putting them in sternal or dorsal if at all possible- dont want to worsen injury

Question 21

When is a vertebral fracture considered unstable?

Answer 21

When 2/3 compartments are affected

Question 22

When should CT/MRI be persued?

Answer 22

When there is no obvious radiographic lesions, the lesions are discordant with localization, when surgery is indicated or when you are trying to evaluate the integrity of the spinal cord

Question 23

What is the common treatment protocol for a stable injury?

Answer 23

6 weeks of cage rest + analgesics

Question 24

What is the common treatment protocol for an unstable injury?

Answer 24

Surgery in most cases -can consider conservative on a case by case basis

Question 25

What are the indications for conservative management with an unstable injury?

Answer 25

If it is a cervical fracture (cervical surgery has high morbidity/mortality), if it is a caudal lumbar or lumbosacral fracture with minimal neurologic deficit, if there is no significant concurrent injuries, if deep pain is intact -external coaptation is required in these cases

Question 26

Describe external coaptation for fracture stabalization

Answer 26

You should make no attempt to reduce the fracture or luxation before or after putting on the brace- it is difficult to achieve anatomic reduction and rigid fixation

Question 27

For conservative treatment, what should the followup look like?

Answer 27

First hospitalize for 2-5 days to assess pain control, neuro status, bladder/bowel function and its affect on the brace, and coaptation tolerance. Then recheck weekly for the next 3 weeks (if need for analgesia continues past 2 weeks consider stronger meds), repeat rads at 4 weeks and remove coaptation when there is evidence of healing

Question 28

What are the indications and goals of surgical treatment for back cases?

Answer 28

Indicated when unstable injury with moderate to severe neurologic signs. Goals are to reduce the malalignment, achieve rigid fixation, +/- decompress the spinal cord

Question 29

When is decompression of the spinal cord indicated?

Answer 29

If imaging confirms cord compression due to displaced fracture fragment, disc rupture, compressive hematoma, or penetrating missile

Question 30

What are the advantages and disadvantages to pins/screws and bone cement for repairing back injuries?

Answer 30

Advantages: excellent strength against lateral bending, easily adaptable configurations applicable in all anatomic areas, no need to remove implants Disadvantages: low resistance to dorsoventral bending, chance of implant failure

Question 31

What are the main considerations when deciding on surgery in cervical vertebral trauma cases?

Answer 31

Severe injury may result in death, the canal cord diameter is favorable which encourages healing, there is a low incidence of body fractures, a high surgical mortality, good success with conservative treatment, and prognosis greatly is improved with early referral

Question 32

What are the main considerations for thoracolumbar injuries?

Answer 32

Surgery is indicated if unstable. It is difficult to rigidly immobilize, there are severe consequences if decompensation occurs, and residual deficits are common with conservative therapy

Question 33

What are the main considerations for lumbosacral injuries?

Answer 33

The lumbar spine is mobile and sacrum is immobile (stress riser region) -the nerve roots of the cauda equina are more injury tolerant than the spinal cord -most morbidity is associated with incontinence

Question 34

What species are sacrocaudal luxations most common in?

Answer 34

Tail pull injuries are common in cats, occurs when there is traction/avulsion trauma to the S1-S3 segments

Question 35

What are the clinical signs associated with sacrocaudal luxations?

Answer 35

plantigrade stance with paraparesis-usualy transient -a week/paralyzed, flaccid tail -diminished/absent perineal reflex, anal tone, and tail pain perception -urinary/fecal incontinence -concurrent injuries are common in 80% of cases (especially with vehicular trauma, pelvic, pelvic limb fractures)

Question 36

What is the treatment for sacrocaudal luxation?

Answer 36

Cage rest, analgesics, bladder management -tail amputation may be indicated but there is also a variety of internal fixation methods

Question 37

What is the prognosis for sacrocaudal luxation?

Answer 37

Most cats will show clinical improvement within 2 weeks of the injury. 75-100% of cats with intact pain sensation will have urinary function return, and 90% will have tail function improve/return -if there is absent sensation, many will still have urinary function return -absent of perineal or tail sensation >30 days poor prognostic indicator

Question 38

What is the most important indicator for prognosis in sacrocaudal luxation cases?

Answer 38

Tail and perineal sensation