Chapter 31 Cervical Vertebral Column and Spinal Cord Flashcards
(119 cards)
1
Q
Why might animals with cervical spinal cord disease present with more pronounced pelvic limb dysfunction vs thoracic limb
A
Because descending UMN tracts to pelvic limbs are more peripherally located than those responsible for thoracic limb motor function.
2
Q
In what scenario might thoracic limb motor dysfunction be more profound than in the PLs
A
Lesion affecting central aspect of SC = “central spinal cord syndrome”
3
Q
What spinal cord segement does lateral thoracic nerve come from?
A
C8-T1
4
Q
Which nerve is responsible for each area?
A
5
Q
From what spinal cord segements does phrenic nerve come?
A
C5-C7
6
Q
SC lesion affectign which segments can –> horners?
A
T1-T3
(likely to be accompanies by ipsilateral reduction in reflexes helps to localise horners to SC segment vs a more peripheral issue)
N.B. leisons cranial to T1-T3 can sometimes cause horners
7
Q
What area of Sc damage typically causes incontinence?
A
Dorsal portion
8
Q
Damnit v ddx for C1-C5 myelopathy
A
9
Q
Damnit v ddx for C6-T2 myelopathy
A
10
Q
Name 3 approaches to cervical vertebral column
A
- Ventral approach (+ modified between sternohyoideus and sternocephalicus)
- Lateral approach
- Dorsal approach
11
Q
List 3 benefits to modified ventral approach to cervical vertebral column
A
- Protection of tracheal, recurrent laryngeal and vagosympathetic trunk
- Increased exposure
- Less likely to cause haemorrhage from caudal thyroid artery
12
Q
List two ventral approaches to AA joint
A
- Ventral apprach
- Modified ventral approach (between sternocephalicus and sternothyroid)
13
Q
Name anatomical landmark for ventral C1
A
Ventral tubercle on caudal aspect of C1
14
Q
Describe the lateral approach to cervical vertebral column
A
See figures in the book - helpful. Approaches book makes most sense!
- Skin incision from C2 to cranial margin of the scapula at the level of the cervical zygapophyseal
- Incise platysma to expose underlying brachiocephalicus and trapezius muscles.
- In the cranial cervical region, the splenius and serratus ventralis are exposed by bluntly dividing and retracting the brachiocephalicus muscle in a direction parallel to its individual fibers, using a grid technique (Figure 31.5).
- Superficial fibers of the serratus ventralis muscle are bluntly divided and retracted, facilitating exposure to the medial fibers of the serratus ventralis muscle, which are subsequently bluntly dissected from the underlying muscles of the longissimus system.
- To approach the C5-C7 vertebral segments, the splenius and serratus ventralis muscles are exposed by separating the brachiocephalicus muscle craniolaterally and the trapezius muscle in a caudodorsolateral direction after insertion of a self-retaining retractor in the fascial plane that naturally divides these muscles (Figure 31.6).
- The superficial cervical artery and vein, which are located between the brachiocephalicus and trapezius muscles, are then isolated, ligated, and divided.
- Exposure to the C6-C7 vertebral segment is further facilitated by simultaneous abduction and caudal retraction of the scapula. Retraction of the scapula is performed to expose the articulation of the C6-C7 vertebrae without the need to incise the muscular attachments on the cranial border of the scapula.
15
Q
Name anatomical landmark of c6
A
Prominent transverse processed of c6
16
Q
Describe approach to brachial plexus
A
- Curvilinear incision 3 to 4 cm cranially from midpoint ofcranial border of scapula to slightly distal to the greater tubercle.
- Inscise platysma muscle and cervicsl fascia cervical fascia, exposing brachiocephalicus, omotransversarius, and trapezius muscles.
- The superficial cervical artery and vein, which emerge between the brachiocephalicus and trapezius muscles, is ligated. The superficial cervical lymph node, lying medially to these vessels, is retracted caudally.
- Inscise omotransversarius muscle near insertion on spine of the scapula and retracted cranially.
- Continue dissection medially along the dorsal border of the brachiocephalicus, which is withdrawn ventrally. A Gelpi retractor is positioned between brachiocephalicus and trapezius muscles.
- The scapula is withdrawn caudally with a Farabeuf retractor. The extrathoracic part of the brachial plexus can now be exposed and palpated ventrally.
- The ventral branches of C5-T1 spinal nerves are exposed by transecting the superficial and deep portions of scalenus muscle. The spinal nerves can be found deep to the scalenus muscle.
17
Q
whch direction does AO joint move? and AA joint?
A
AO joint = yes joint
AA joint = no joint (primarily moves by rotation)
18
Q
How many foramina are there in the atlas and what runs through each?
A
3 foramina (2 paired): vertebral foramen, transverse foraminae, lateral vertebral foraminae
Vertebral foramen: SC
Transverse foramina: Vertebral artery on its way to lateral vertebral foramen
Lateral vertebral foramen: Vertebral artery + vein and first cervical spinal nerve
19
Q
Label the diagram
A
20
Q
How many centres of ossification does the atlas have?
And the axis?
When do the fuse?
A
Atlas 3 centres of ossification (dorsal arch fused 106d, ventral 115d)
Axis 7 centres of ossification (up to a year for full fusion)
21
Q
Name the ligamentous structures of the aa joint
A
- AA ligament
- Transverse ligament
- Apical ligement (–> basioccipital bone)
- Alar ligament (paired) (–> occipital condyles)
22
Q
Name 6 possible anomalies of the AA joint (that may predispose to aa sublux)
A
- Dysplasia
- Hypoplasia/Aplasia
- Dorsal angulation/separation of the dens
- Absence of transverse liagement
- Incomplete atlas ossification
- Block vertebrae
23
Q
Anatomical reason mini breeds are prone to aa sublux
A
Dens prone to maldevelopment due to aberrant physeal growth plate closure in miniature breeds
24
Q
What is most common cs of aa sublux?
A
Gait dysfunction (94%)
25
How is aa lux dx on rads?
* Increased space between dorsal lamina of atlas and spinous process of axis (should rest on dorsal lamina of atlas)
* (AA angle \<162º more predictive of aa instability than decreased aa overlap)
A, Lateral radiograph of the cervical vertebral column in a slightly extended position, which does not normally reveal such obvious separation between the cranial aspect of the spinous process of C2 (arrow) and the laminae of the atlas (arrowhead).
B, Ventrodorsal radiograph of the occipitoatlantoaxial articulation of the same dog as in A, revealing a markedly hypoplastic dens (odontoid process) (arrow).
C, A flexed lateral radiograph of the cervical vertebral column demonstrates marked subluxation of C1 (arrowhead) and C2 (arrow) vertebrae. Such a view is not uniformly recommended because it can be associated with a high risk for further neurologic compromise.
26
Comment on use of extrenal coaptationin AA lux (3 points)
* Aim to stabilise AA while ligamentous structures heal
* Must extend from rostral to ears to include thorax
* External coaptation likely to lead to recurrent/progressive signs
27
List 9 complications associated with external copatation for AA
1. Recurrence of disease
2. Corneal ulcers
3. Splint migration --\> ineffective
4. moist dermatitis/ulcers
5. Hyperthermia
6. respiratory compromise
7. anorexia
8. OE
9. Accumulation of food in splint
28
In what situations might exteral coaptation for AA be considered (sugery generally advised)
* Financial limitations
* Poor systemic health
* younf patient (wait for growth before sx)
* Severe neuro dysfunction so assess poss prognosis before committing to sx.
29
Name a contraindication for dorsal AA stabilisation
In which scenario might dorsal technique be preferable?
Dorsal deviation of the dens
Animals \<2kg or if ventral stabilisation has failed
30
Which technique (dorsal vs ventral) is preferred for AA stabilisation and why?
What is complication rate of dorsal AA stabilisation techniques vs ventral?
What % of dorsal technique cases had good/excellent outcome?
And with ventral technique?
What is overall reported failure rate with dorsal vs ventral technique
* Ventral preferred as possibility of bony ankylosis
_Complication rate:_
* Dorsal 71%
* Ventral 53%
_Good/excellent outcome:_
* Dorsal 62% g
* Ventral 47-92%
_Overall failure rate:_
* Dorsal 48%
* Ventral 44%
31
Name 4 techniques for dorsal AA stabilisation
And 4 for ventral
_Dorsal:_
* Kishigami AA tension band
* Nuchal ligament technique
* Dorsal crosspinning + PMMA
* Dorsal AA wiring (also reported suture between muscles in X-fashion)
_Ventral:_
* Transarticular screws/pins
* Pins + PMMA (i.e transarticular pins AND perpendicular pins + PMMA)
* Screws + PMMA
* Ventral plating
32
Name a benefit of kishigami AA tension band over other dorsal techniques
Reduced risk of SC damage
33
List 4 technique for reduction/temporary stabilisation of AA lux, from ventral approach
1. Bone screw in caudal C2 vertebral body
2. Halsted forceps over vertebral body
3. Instrument in C1-C2 IVD space
4. Gelpi with an armi in AO space and other in C2-C3 space
34
At what angle should transarticular screws for AA lux be placed, from medial to lateral and from ventral to dorsal
What screw size?
* 40º from medial to lateral (aim to come out medial to alar notch)
* 20º from ventral to doral
3-5mm corridor
1.5mm screw
35
What are the two described screw placement configurations in *axis* for ventral AA stabilisation
Atlas:
* (same for both): Medial aspect of each atlas wing (caudal to transverse foramen) +- a third midline (not penetrating vertebral canal)
Axis:
* Four screws in body (one screw is placed in the middle of the caudal aspect of each of the cranial articular surfaces of the axis at the insertion point of the longus colli muscle. The screws are directed craniolaterally at 30 to 40 degrees. The second pair of screws is placed at the base of the transverse processes of the axis or in the C3 vertebra and is directed laterally at 30 to 40 degrees to the midline. With this technique, Steinmann pins or Kirschner wires can be used to bridge the screws; the pins or wires are positioned parallel to midline and are secured by orthopedic wire to the screws)
* Two in body, along midline (one can be used initially for reduction.
Encased in PMMA
36
Name 2 plate types used for ventral aa plating
* H-plate (2.0mm)
* Five hole butterfly plate (1.5mm)
37
List 5 possible complications following AA stabilisation sx
1. Neurological deterioratioon
2. Respiratory compromise (lar par, racheal necrosis from PMMA, aspiration)
3. Implant failure
4. Fracture
5. Recurrent pain
38
What factor was associated with good outcome following conservative management?
What factors were associated with good outcome following surgical management?
Conservative management:
* Affected for \<30d
Surgical management:
* Age of onset \<24 months
* Affected for \<10 months
* Lower severity of clinical signs
39
Which method of surgical management for AA lux reported to have least success?
Transarticular pins alone (cf multpile pins/scres and PMMA)
40
Which spinal cord segments contribute to brachial plexus?
C6-T2
| (and C5 in 24% of dogs)
41
Partial brachial plexus injuries most commonly affect the spinal nerve roots that contribute to the whih (*cranial or caudal)* portion of the brachial plexus
Caudal
42
Describe the crossectional anatomy of peripheral nerve
Endoneurium surrounds each axon
Groups of axons are surrounded by perineurium
The connective tissue around the entire nerve, called the epineurium
43
What are the 13 named nerves of the brachial plexus/direct continuations of formative spinal nerves?
1. Brachiocephalic
2. Suprascapular
3. Subscapular
4. Musculocutaneous
5. Axillary
6. Radial
7. Medial
8. Ulnar
9. Dorsal thoracic
10. Lateral thoracic
11. Long thoracic
12. Pectoral
13. Muscular
44
When do spinal nerves forming brachial plexus become named nerves?
As they exit plexus
45
Where along the nerve anatomy does brachial plexus injury most commonly occur?
Intradurally where nerve root arises from SC. Lack epineurium here so weak
If damage is severe may lead to SC injury to --\> PL ataxia/UMN paresis/plegia
46
Describe the classes of traumatic nerve injury.
Class 1:
Class 2
47
Brachial plexus injury is divided into 3 types, what are they and what are the associated exam findings?
1. Injury to cranial portion (C6-C7 = Suprascapular, subscapular, musculocutaneous, axillary).
* Rare.
* Few c/s. Loss of shoulder movement and elbow flexion
2. Injury to caudal portion (C8-T2 = radial, median, ulnar nerves)
* More common, radial nerve involved in 92% of brachial plexus injuries.
* Limb may be flexed as musculocutaneous, axillary and suprscapular nerves intact. No elbow or carpal extension. High proportion have Horner's or loss of cuteneou strunci reflex (C8-T1)
3. Injury to all spinal nerve roots (C6-T2)
* Drag limb, knuckled.
48
Describe the sensory loss associated with cranial- , caudal- and complete brachial plexus injury
49
What is the acronym for remebering order of brachial plexus nerves? And their spinacl cord segment they originate from?
SSMARMU!!
50
How can degree of brachial plexus injury be further investigated
* Nerve conduction velocity
* (EMG allows detection of abnormal spontaneous acivity 7-10d post-injury)
* Sometosensory evoked potential
* **MRI!** retracted distal nerve root or nerve retraction ball may be seen. Check Sc too
51
List 2 surgical techniques for potential management of brachial plexus injury
Complications?
* Neurotization (sacrificing donot nerve to restore recipient nerve/muscle function)
* Reimplantation.
* Lateral approch to cervical vertebral column and brachial plexus. Hemilaminectomy. Durotomy Slits in pia mater - dorsal to white matter only, ventral into grey matter
Neurologic deterioration with re-implantation may --\> significant ipsi or bilateral pelvic limb dysfunction for 2 weeks!
52
What is recommended post-op care following nerve repair
7 bandage if no tension,
If tension then immobilize limb for 3 weeks then gradually extend.
Because it takes 3 weeks for for adequate collagen sythesis and deposition to splint nerve internally.
53
What re 3 types of surgical nerve *repair*
Eepineural, fascicular, and graft repair.
## Footnote
Direct end-to-end neurorrhaphy is carried out using an **epineurial repair** approach (upper panel), which entails placing sutures through the epifascicular epineurium and bringing the nerve stumps into approximation.
**Fascicular repair** (upper panel) involves placing sutures through the perineurium.
**Graft repairs** (lower panel) are performed when direct end-to-end neurorrhaphy would cause excessive tension on the repair site. The graft material is harvested from a “nonessential” nerve and is then sutured between fascicles.
54
Of 35 dogs treated for AA lux with ventral screws + PMMA, how many had major complications and what were they (Steele, VetSurg 2016)
Major complications in 9/35
55
What did Moissonnier et al (VetSurg, 2017) report as a treatment options for caudal brachial pexus avulsion in 3 dogs?
What was long-term outcome
C8 cross transfer
Variable 2/3 needed phalanx amputation due to self-mutilation
56
Comment on dorsal vs ventral thickness of annulous fibrosus
1.5 - 3x thicker ventrally vs dorsally
57
Comment on the thickness of the dorsal longitudinal ligement in the cervical spinal cord
Thickest in cerbical spinal cord (vs elsewhere) --\> greater resistance to NP extrusion. i.e. cervical disc *protrusion* more common than *extrusion.*
58
In chondrodystrophic breeds, which cervical disc spaces are most commonly affected with IVDD?
C2-C3 (60%)
(C2-C4 (80%))
59
What are the most common clinical signs of cervical disc herniation?
Cervical hyperaesthesia and lameness/nerve root signature
(60% have no neuro deficits)
60
What % of dogs with cervical disc herniatinon have reduced thoracic limb reflexes?
34%
61
What is the typical clinical presentation of cervical HNPE?
Mild pain, more neurologivcally severe
| (often non-painful, non-ambulatory)
62
List 6 differentials for cervical IVDH
1. AA sublux
2. Meningitis
3. Meningomyelitis
4. Neoplasia
5. CSM
6. Discospondylitis
63
What are the two sites for csf collection?
Cisterna magna and LS subarachnoid space
64
What biomarker in CSF is positively associated with severity of SC damage?
i.e. may serve as prognostic indicatior
microtubule-associated protein tau
65
What is teh accuracy of plain rads for dx of site of IVDE?
35%
66
How can lateralized/formainal disc material be better assessed using myelography?
Oblique view
A: A lateral myelogram of the cervical vertebral column demonstrating compression of the spinal cord at the C3-C4 intervertebral disc space. Note the attenuation of the contrast medium in the dorsal subarachnoid space at dorsal articulation of C3-C4. Ventrally, the subarachnoid space also is attenuated (arrow). Additionally, there is “splitting” of the ventral contrast column suggestive of a lateralized or ventral midline extradural lesion.
B: A ventral oblique view reveals attenuation of the contrast medium in the subarachnoid space along the right side of the spinal cord (arrow), which suggests a lateralized extradural lesion.
67
What is the classical sign of HNPE on MRI
How does the extruded material look on T2, STIR and T2 FLAIR?
"Seagull sign"
T2: Isointense to CSF
STIR: Isointense to CSF
T2 FLAIR: Supressed
A sagittal (A) and transverse plane (B) T2-weighted magnetic resonance image of the cervical vertebral column of a dog with hydrated nucleus pulposus extrusion at the C4-C5 intervertebral disc space (arrow) and consequent compression of the spinal cord.
68
List the three groups that dogs with cervical IVDE can be classified into.
What are sx recommendations?
* Group 1: First episode, neck pain only
* Group 2: Repeated neck pain only
* Group 3: Neck pain + neuro defecits
Sx necessary for group 3, recommended group 2
69
List 3 techniques for decompresson of the cervical spinal cord
* Dorsal laminectomy
* Ventral slot (+slanted ventral slot)
* Hemi
70
List 2 advantages of ventral approach to cervical SC for IVDH
And 3 disadvantages
_Advantages:_
* Minimal muscle dissection
* Access to fenestrate
_Disadvantages:_
* Poor field of view
* Insufficient access for lateral/foraminal lesion
* Risk of haemorrhage
71
What are the sirgical size limits for ventral slot and why
33% width of vertebra (up to 50%)
33% length
Risk of bleeding or vertebral destabilisation --\> subluxation
72
How does a piezoelectric devise work? At what frequency does it work?
Low frequency US waves (25 - 30 kHz) --\> microvibrations 60-210 um.
The microwaves can only cut mineralised tissue ie safe around neurovscular structures (need 50kHz to cut ST)
73
How does slanted ventral slot differ from regualr ventral slot?
What is proposed adantage
Removes caudal apect of cranial vertebral body (20% width, 20% length)
--Access without removing large portion of annulus --\> increased stability (not biomechanically evaluated)
74
What are recommendations re fenestration and animal size
Not in dogs \>30kg
75
What is major complication rate and mortality rate for ventral slot?
Major complications 15%
Mortality 3%
76
List 6 potential complications of ventral slot sx
1. Haemorrhage
2. Arrythmias
3. Subluxation
4. Respiratory compromise
5. Neuro deterioration inc Horner's
6. Seroma (esp dorsal laminectomy)
77
In relation to ventral slot surgery, when does subluxation usually occur?
Within 1 week
78
what is remorted recurrence rate following sx for cervical IVDH?
What timeframe?
5-10%]
Mean time 3 months
79
What are the two types of CSM and which breed/age is typically associated with each?
Disc associated - 7yr Dobermann
Osseous associated - 4yr Great Dane
80
Name two anatomic features of large breed dogs that may account for them getting CSM, vs small dogs
* Proportionately smaller vertebral canal:SC diameter
* Funnel shaped vertebral foramen, particularly affecting caudal cervical vertebrae
81
List the three factors that act in combination to explain pathophysiology of disc associated CSM
1. Vertebral canal stenosis
2. Pronounced torsion of caudal cervical intervertebral column --\> IVD degeneration
3. Protrusion of larger volume disc
82
Which disc spaces are most commonly affected by disc associated CSM?
C5-C6 and C6-C7
(caudal cervical column has x3 more torsion than cranial --\> disc degeneration)
83
In osseous associated CSM, which structures are associated with osseous proliferation?
* Laminae (dorsally)
* Articular processes (dorsolateral)
* Pedicles (lateral)
84
Which ST structures can be hypertrophied in CSM
* Yellow ligament
* Dorsal longitudinal ligament
Seen with both disc and osseous associated CSM, rarely seen in isolation.
85
What 4 factors should be taken into consideration when planning sx for CSM
* Site of compression (dorsal, ventral or lateral)
* Source of compression (disc, osseous, ligamentous)
* Single or multiple sites
* Static or dynamic
86
In dogs, what was the difference in vertebral canal diameter (%) between flexed and extended positioning?
which was smaller?
29% difference
Smaller when extended
87
Apoptosis has been shown to be present in SC of dogs with CSM. Which cell type is most affected
Oligodendrocytes i.e. interference of remyelination.
88
What is most common presenting c/s in dogs with csm?
Gait abnormalities
89
List the three main *radiographic* changes in disc associated CSM
* Changes in shape of vertebral body
* Narrowed IV disc space
* Vertebral canal stenosis
N.B. 25% of clinically normal Dobermans have similar rad changes.
Lateral (A) and ventrodorsal (B) radiographic images of a 5-year-old Great Dane with osseous-associated cervical spondylomyelopathy. Note severe, osteoarthritic proliferative changes (arrows) throughout his cervical vertebral column in the radiographs.
C, Dorsal T2-weighted magnetic resonance imaging shows bilateral spinal cord compression (arrows) in the caudal cervical region.
90
HOw does myelography compare with MRI for assessment of CSM?
May underestimate severity of compression and indicate a different site.
91
List 2 common complications of myelography
* Neuro deterioration
* Seizures
92
What 3 additional tests shoudl be considered in CSM cases (think Doberman diseases..)
* VWF: vWF antigen assay
* Thyroid function
* Echo: for DCM
93
What reported rate of improvement in medically managed CSM cases vs surgically managed?
54% improved with medical management
81% with surgery
94
Broadly speaking, what are the three categories of surgical management of CSM
* **Direct decompressive**
* Dorsal laminectomy
* Ventral slot/inverted cone
* Hemilaminectomy
* **Indirect decompressive**
* Pins/Screws + PMMA
* Screw Bar - PMMA
* PMMA plug
* Locking plate
* Alternative techniques
* Titanium cage
* PEEK cage
* Others
* **Motion preserving**
* ****Cervical disc arthroplasty
95
Broadly speaking, what is surgery type for disc associated CSM?
And osseous associated
_Disc associated:_ Ventral slot/inverted cone. Thought to be dynamic so +- distraction-stabilization technique
_Osseous associated:_ Dorsal laminectomy (/hemi). Throught to be primarily static but can consider distraction-stabilization too.
96
List 3 surgeries that allow direct decompression of CSM
* Ventral slot/inverted cone
* Dorsal laminectomy
* Hemilaminectomy
97
How many adjacent ventral slots can be performed?
2
(but higher risk of complications)
(Therefore for CSM primarily indicated for decompression of *single, ventral* site)
98
What is the reported long-term success rate for the following procedures for management of CSM?:
* Ventral slot
* Dorsal laminectomy
* Distraction-stabilization with metal implants + PMMA
* PMMA plug
* Locking plate (3 case series)
_Long term success rate:_
* Ventral slot: 72%
* Dorsal laminectomy: 79 - 95% (30% recurrence)
* Distraction-stabilization with metal implants + PMMA: 73%
* PMMA plug: 82%
* Locking plate: 73%
99
How does inverted cone differ form ventral slot?
20% length and width of vertebral body only!
(Less risk of haemorrhage and collapse)
100
What is the procedure name when multiple adjacent dorsal laminectomies are performed?
Continuous dorsal laminectomy
101
What is the width landmark for dorsal laminectomy?
Inside articular processes
102
What is the main 'downside/concern' re dorsal laminectomy
High morbidity
70% are worse post-operatively
103
With CSM dogs undergoign dorsal laminectomy, list 3 risk factors associated with post-op deterioration
1. *Ossseous* associated CSM
2. More severe neuro status
3. Prolonged surgery time
104
List 4 indirect decompression techniques for management of CSM
1. Distraction-stabilization with **metal implants + PMMA** (+ ventral slot)
2. **Screw bar - PMMA**
3. Distraction using **PMMA plug**
4. **Locking plate** (w partial ventral slot or discectomy + bone graft)
5. **Alternative techniques** e.g. titanium cage, intervertebral spacer, intervertebral cage of carbon fibre reinforced polmyer (PEEK), intervertebral traction screw + plate.
Lateral radiograph of polyetheretherketone (PEEK) cage and locking plates in a 7-year-old Doberman Pinscher with cervical spondylomyelopathy.
105
How many sites can PMMA plug for CSM be used on.
3 sites
(can be used for dorsal or ventral, and static or dynamic i.e. popular as versatile)
106
Briefly describe PMMA plug procedure for CSM (5 steps)
1. Discectomy leaving 3-5mm of dorsal annulous intact
2. Traction
3. Anchor holes drilled into cranial and caudal end plates
4. Inject PPMA
5. Cancellous bone graft ventrally (forage holes in vertebral bodies. N.b. bony fusion not observed in any)
107
List 4 alternative techniques for management of CSM
_Alternative techniques:_
* Titanium cage
* Intervertebral spacer
* Intervertebral cage of carbon fibre reinforced polmyer (PEEK)
* Intervertebral traction screw + plate.
108
Name a motion preserving technique for management of CSM .
How many spaces can it be used for?
Supposed advantage?
Outome?
* Disc arthroplasty
* 2-3 spaces
* Advantage = allows decompression by dorsal annulectomy
* 91% positive outcome (100% subsidence though)
109
Name a motion preserving technique for management of CSM .
How many spaces can it be used for?
Supposed advantage?
Outome?
* Disc arthroplasty
* 2-3 spaces
* Advantage = allows decompression by dorsal annulectomy
* 91% positive outcome (100% subsidence though)
110
List 7 possible complications following surgery for CSM
1. Neuro deterioration
2. Vertebral or transverse forament penetration w implants
3. Domino effect (adjacent segment syndrome)
4. Laminectomy membrane
5. Implant failure
6. Collapse of intervertebral foramen
7. Insufficient decompression
111
In what % of CSM dogs is neuro deterioration documented following
dorsal laminectomy
ventral slot
dorsal laminectomy 70%
ventral slot 42%
112
For ventral distraction-stabilization with Pins and PMMA, what is recommended angle of insertion?
30-35º at C5 and C6
45º at C7
113
IN what % of surgically treated CSm cases is adjacent segment syndrome reported?
20%
114
What surgical step is recommended to avoid laminectomy membrane formation?
Dont place free fat graft
115
What was MST of dogs treated for CSm medically?
And surgically?
36 months for both
116
What are the two types of extradural synovial cyst and what is the difference ?
**Synovial cyst** (epithelial cell lining)
**Ganglion cysts** (no lining, thought to result from mucinous degeneration)
117
What two diseases do extradural synovial cysts tend to be associated with
Degenerative LS disease
CSM (occassionally, 20% of osseous CSM cases)
118
What is a consistent clinical sign in dogs with *cervical* extradural synovial cysts?
Neck pain
(cf. only present in 5% of CSM dogs generally)
119
What is shown in images?
Synovial cyst in the cervical region of a Rottweiler Dog with cervical spondylomyelopathy. Sagittal (A) and transverse (B) T2-weighted MR images showing the synovial cyst at C5-C6 (arrows). Note the enlarged articular process associated with the cyst in B.
Sagittal plane T2-weighted magnetic resonance image of the lumbar vertebral column and sacrum of a 1.5-year-old German Shepherd Dog, exhibiting multiple extradural synovial cysts (arrows).
