Cervical Flashcards
what is the overall recurrence rate for disc-associated CSM (cervical spondylomyelopathy)?
24%
what is success rate for medical management of CSM?
38 -54%
what is success rate of IVD fenestration alone?
30-33%
where do meningioma of spinal cord most commonly occur?
cervical - often cranial to C3
what breed is predisposed to meningioma?
boxer
lrg breed dogs
what is prognosis with surgery for meningioma
19 mo.
those that survive 3 months and neuro signs improve have good prognosis
recurrence possible
what are advantages of cervical disc arthroplasty? long term success?
- allowing decompression of spinal cord with dorsal annulectomy, assuring direct decompression
- can be used to treat 2-3 consecutive cases
- 91% BUT subsidence in all dogs
AND intravertebral mobility lost or not detectable in 77% of operated sites
what is chemonucleolysis?
inject IVD with chondroitirase ABC
- 7 d post injection 92% have some improvement
- 77% have excellent improvement
what is a piezoelectric device? what are the benefits?
- ultrasonic tool for osteotomy/osteoplasty (use low freq 25-50 Hz) to help cut bone for ventral slot
- benefit - can adjust so only cuts mineralized tissue and not soft tissue
which cervical vertebrae is associated with better prognosis?
cranial to C4 (some papers disagree)
- <15kg dog with caudal have poorer prognosis
what is prognosis for cervical IVDD with relation to:
- degree of CNS injury
- duration of disease
- type of treatment:
- degree of CNS injury: even tetraplegia can make full recovery
- duration of disease: dogs that dont walk within 2 week more likely to have residual effects
- type of treatment:
1 - recurrence rate >/= 36% with conservative treatment
2 - V slot = 90% recovery in 1 month; 97% recovery in 12 months; recurrence 5-10%
3 - dorsal lam - 100% in one study
4 - hemilam - better smaller breeds 78-90%
what are 3 factors associated with disc associated compression? age of dogs with DACSM?
vertebral canal stenosis
pronounced torsion of caudal cervical intervertebral column - IVDD
protrusion of larger IVD in caudal cervical column
Age = middle age large breed
what causes narrowing of osseous associated CSM? age?
stenosis - proliferation of lamina, articular process, or pedicles
Age = young giant breeds
what angle between atlas and axis is predictive of instability?
<162 degrees
complications of conservative management for AAI?
recurrence of disease, corneal ulcers, migration of splint (ineffective), moist dermatitis, decubital ulcers, hyperthermia, respiratory compromise, anorexia, otitis externa, accumulation of food in badnage
what is the main contraindication for dorsal technique for AAI?
spinal cord compression from dorsal deviation of dens
list dorsal techniques to address AAI
atlantoaxial wiring (or w suture)
nuchal ligament technique
dorsal cross-pinning (+PMMA)
kishigami AA tension band
what is the toughest (cautious) step of kishigami?
insert over dorsal arch of atlast in subarachnoid space
what/how is slanted ventral slot created?
removes caudal aspect of cranial vertebral body of affected IVD
- window created cranial to IVD few mm from ventral crest of body
- ~20% width (20-25% length) direct toward vertebral endplate
what size dog dog we not recommend doing cervical fenestration
> 30kg (arbitrary?)
list complications of sx to treat cervical IVDD
resp compromise:
1- type 1 - ventilatory failure 2ndary to paralysis/paresis
2- type 2 - ventilating normal. pneumothorax or atelactasis with recumbency/anesthesia
cardiac dysrhythmias
hemorrhage: 19% in Ross. study
neuro deterioration: + lar par/Horners
vertebral subluxation: 8% in one 2000 paper
seroma
what is overall complication rate of sx cervical IVDD?
9.9% (Rossmerzel 2013)
minor - 3.5%
major - 6.4%
hemorrhage 18.9% (only 5 needed transfusion)
list ventral techniques of AAI surgery?
transarticular screw + pins
pins and PMMA
screws and PMMA
Ventral plating:
1- mini H plate variant
2 - butterfly plate variant
what are the 2 patterns for screw placement in body of axis for AAI stabilization?
1 - 4 cortical screws in body; 1 in middle of caudal aspect of each cranial articular surface of axis at insertion point of longus colli
2 - 2 cortical screws, 1 screw to facilitate secure realignment. 2nd screw placed in cranial 1/2 of vertebral body of axis (this technique uses transarticular pins)
what is typical gait in dog with CSM?
general proprioceptive ataxia even with absence of postural reaction deficit (typical PL ataxia, mild changes in TL)
what % are non-ambulatory tetraparetic?
10%
what % normal Dobies have changes on rads similar to dogs with CSM
25%
what is the % seizure complication rate in performing myelography in dobies?
25-27%
for disc-associated cervical spondylomyelopathy, what are typical sx tx plans for:
- ventral static compression
- dynamic compressive
- multiple compressive sites
- ventral static - ventral slot or inverted cone
- dynamic compressive - distraction and stabilization (PMMA plug or pins/screws + PMMA)
- multiple compressive sites - distract and stabilize (most often PMMA plug)
what are 2 additional techniques for multiple ventral compressions?
continuous dorsal laminectomy
cervical disc arthroplasty
what are alternatives options to repair cervical fracture if concerned about transverse foramen
screws in transverse process, joined curve steel bar and encased PMMA
ventrally applied monocortical screw and PMMA fixation (3 screws/vertebra)
- 9.7% monocortical screws penerated vertebral canal
cervical IVD - prevalence of those with IVD?
most common breeds? age?
14-25% (most extrusion)
small - toy poodles/ beagles (chondrodystrohpic)
large - labs, dalmatians, dobies (24% of all cases)
age - mean age 6-8 years; BUT shih tzu/yorkies (older; around 9-10 years)
cervical IVD - which sites are more often affected?
chondrodystrophic - 80% are C2-C4
44-59% C2-C3 aloine
yorkies/chihuahua - caudal C5-6 or C6/7
what are advantages of paramedian approach to ventral cervical column?
protects carotid sheath, exposes caudal vertebrae, decrease risk of hemorrhage from right caudal thyroid artery
with lateral approach to brachial plexus, what muscle needs transecting to show ventral branches of 5-8th cervical nerves?
scalenus muscle
what are indications of lateral approach to cervical region?
lateral or foraminal IVD herniation, nerve sheath neoplasms involve spinal nerve or spinal nerve roots and lesions in lateral epidural space
