3nd CDA Lecture - Dr Adamo - May 7, 2015 - Oquendo Center
1. 3rd Cervical Disc Arthroplasty (CDA)
Practical Course
Speaker:
F Adamo, DVM, DECVN
Instructors:
F Adamo, DVM, DECVN
R Kroll, DACVIM (Neurology)
C Giovannella, DACVIM (Neurology)
2. Course Objectives
Mastering the CDA technique
Avoid common mistakes
Enable you to perform CDA independently on
your first clinical case
Additional supervision is available upon request
3. Morning session:
1st hour:
History of CDA & description of the instrumentation
Recent clinical data
Video of the technique in a clinical case
2nd hour:
Dr. Kroll lecture
Frequently Asked Questions
Practice CDA on canine plastic cervical model
Afternoon session:
3 hrs Practice CDA on canine cadavers
1 hrs Discussion & Certification
Cocktail/Appetizers
Course schedule
4. Registry Approved Continuing Education (RACE)
RACE approved for 5 hrs of CE
To receive the CE- credit hrs at the end of this course you
have to fill out:
Participation Evaluation form
14 post-test questions
5. Padfolio content:
Schedule
Printed copy of the CDA surgical technique
FAQ questions + answers
Test: 14 questions for RACE
Evaluation form
CE credit certificate
Other information:
- dropbox
- wobblersyndrome.com
CDA course
7. Goals:
Preserve motion after neural
decompression while providing
distraction and stability
Potentials:
May prevent “domino lesions”
Advantages:
Treatment of multiples adjacent
& not adjacent spaces
CDA
Indications:
Disc Associated Wobbler Syndrome
8. Phase 1.
DESIGN
Madison, WI 2003
Phase 2.
IN VITRO BIOMECHANICAL STUDY
Adamo, Kobayashi et al. Vet Surgery 2007
4 Groups of 6 cervical spines (C5-C6)
a) Arthroplasty,
b) Ventral Slot,
c) Pins+PMMA fixation,
d) and normal spine
The artificial disc was better able
to mimic the behavior of intact
spine compared with ventral slot
and Pin+PMMA groups.
History
9. Phase 3. Pilot clinical study in 2 client-owned
dogs mmmmm with DAWS
Titanium alloy
Results
Follow up to 3½ years post-op
Died for unrelated neurological diseases
MRI re-check 2 years post-op
No evidence of compression at the
treated and adjacent sites
Conclusions
Cervical arthroplasty was well tolerated
and provided excellent outcome in both
dogs
Warranted further study:
Large number of patients
Longer follow-up
Adamo JAVMA, 239(6), 2011
10. Cervical Disc Arthroplasty using
the Adamo Spinal Disc™ in 33 dogs
affected by Disc Associated
Wobbler Syndrome
at Single and Multiple Levels.
In preparation to be Submitted to JAVMA
11. Study Authors
F Adamo, DECVN
East Bay Vet Specialists – CA
R Da Costa, DACVIM (Neurology)
The Ohio State University – OH
R Kroll, DACVIM (Neurology)
VCA Northwest Vet Specialists – OR
C Giovannella, DACVIM (Neurology)
Gulf Cost Vet Neurology/Neurosurgery – TX
M Podell, DACVIM (Neurology)
Chicago Vet Specialty Group – IL
P Brofman, DACVIM (Neurology)
Veterinary Specialty Care, SC
A Multi-Center Prospective Study
12. To evaluate the immediate postoperative recovery,
the short-, intermediate- and long term follow-up
of dogs with one level and multi-level disc-
associated-wobbler-syndrome (DAWS) treated
with cervical disc arthroplasty (CDA).
Objective
13. Material & Methods
Implant: similar to that described in the preliminary study, but
with several modifications.
Adamo JAVMA, 239(6), 2011
Adamo Spinal Disc 2nd & 3rd Gen.
Internal surfaces
Concavity is titanium
Convexity is PEEK
(PolyEther Ether Ketone)
Thermoplastic polymer
Decreases friction
Prevent metallic debris
from a metal to metal joint
Acts as a ball and socket
Patent: US 8,496,707 B2
14. External surface
Convex
To resemble natural concavity
of vertebral end plates
To prevent implant migration
Implant
15. External surface
Concentric grooves
To provide “grip”
To allow bone in-growth into the implant
2nd Generation
Treated with Dual Acid Etch Bath
to promotes bone/implant incorporation
3rd Generation
Treated with Hydroxyapatite
to better promotes bone/implant incorporation
Implant
16. 1st generation 2nd generation
- Ball in PEEK
- Thinner size
3rd generation
- Ball in PEEK
- Thinner size
- Hydroxyapatite
Coating
Implant Design Modification
4rd generation
- Ball in PEEK
- Finally thinner size
- Hydroxyapatite
Coating
- Additional wider
& taller sizes
8.5 mm 8.3 mm
19. Thick end
Parallel channels to hold
the assembled prosthesis
during implantation
Thin end
Slotted to remove the pins
after implantation
Barrel Holder – Double function
Dedicated tools
20. Sizing Probe
• Resemble at each end the shape of either
mthe S, M, or W disc size
•To probe/test the disc space during
nburring, before final disc implantation
Dedicated tools
21. Small burr
• To clean end-plates and begin
creating concavity
Large burr
• matches the external disc
convexity
• To facilitate implant
accommodation by the disc
space
Large burrSmall burr
Two dedicated burrs
Dedicated tools
22. 20 degree angle attachment for the Surgairtome
To facilitate working at an angle parallel to the disc
space during burring
Particularly useful at C6-C7 (and C7-T1 !!)
Dedicated tools
23. Caspar Cervical Distractor
• To maintain vertebral distraction during implantation
• To allow visualization through the disc space to the dorsal
longitudinal ligament
Dedicated tools
25. Sample population:
First 33 clients-owned dogs w/ over 2
mo. history of DAWS
Diagnosed by MRI or CT myelo
Weight over 23 kg, but one (12.2 Kg)
Neurologically and
radiologically evaluated
Prior to surgery
Shortly after surgery
within 24 hrs
At 2 wks & 3, 6, 12 & 24 mo. after
surgery
Including Criteria
26. Total = 50 disc sites treated
Single, two and three level lesions
Neurological Assessment
Grade 0 to 6
De Decker, et al. JAVMA 2012; 240:848–857
C3
C4
C5
C6
Material and Methods
0: No apparent neurological deficits
1: Cervical hyperesthesia w/o deficits
2:: Hind limb ataxia w/o visible paresis
3: Hind limb ataxia with paresis &
no appreciable forelimb ataxia
4:: Ambulatory tetraparesis: broad-
based ataxia hind limbs & choppy
gait forelimbs (“two engine gait”)
5:: Non-ambulatory tetraparesis: able
to stand/walk few steps before collapse
6: Tetraplegia
27. Optimal
Implant well centered in
the disc space on lateral
& VD views
Sub-optimal
Off midline on VD
Inadequate
Not seated in center of
the disc space on lateral
view
Inadequate position
Implant Position
28. Relative Distraction ratio (RDR):
Ratio between post-op and pre-op
width at the treated space
Adequate / Ideal*
RDR > 1.7 and < 2
* Equivalent to a
distraction of 2-3 mm
Under distraction
RDR < 1.7
Over-distraction
RDR > 2
C7C6
C5
C7
C6
C5
Pre-op
Post-op
Distraction
36. Distraction lost compared to immediate post-op,
but maintained when compared to pre-op
All sites
More pronounced with 1st generation (thicker)
implant
Less pronounced with 2nd and 3rd generation
(thinner) implant
Subsidence
Distraction lost compared to pre-op
7/50 sites (14%)
Ventral Osteophytes
2 sites in one dog
Serial Radiographic Assessment
37. Mobility
Present:
at 2 wks post-op in 88% in 24 dogs examined
at 6 mo post-op in 23% in 14 dogs examined
♬ In 7 dogs where dynamic study was
performed immediately after surgery: mobility
although expected was not detectable in 5/10 of
the treated spaces
No Implant migration
No Implant infection
Serial Radiographic Assessment
Ventro-flexion
Dorsi--flexion
38. 6 weeks post-op (1 dog)
Improper technique C6-C7
Declined after surgery
Dorsal compression at C5-C6
due to loss of distraction
Improved with single dorsal
decompression
7 mo. post-op (1 dog)
New osteophytes or
heterotopic ossification
Clinical status unchanged
Dog 2
C5-C6
C5 C6 C7
T2 sagittal MRI
C5-C6 6 wks post – surg
C5-C6 pre – surgery
MRI Re-assessment: 6 dogs
39. 20-24 mo. post-op (4 dogs)
2 dogs: No signs of disc
degeneration or compression at
treated and adjacent sites
2 dogs: New osteophites or
Heterotopic Ossification.
1st and 2nd generation implant
C6
C7*
MRI Re-assessment
C3-C4 C5-C6
In all dogs the implant
didn’t affect the spinal
cord visibility
40. Post-op recovery time
Immediate in all dogs
Neurological status unchanged compared
to pre-op status in all dogs
Post-op hospitalization time *
5 dogs: Discharged same day
25 dogs: 1- 3 days
2 dogs: 4 - 5 days
Based on the severity of the neurological
status pre-surgery
Clinical Assessment
41. Follow-up: Mean 24 mo, (range 2 wks - 42 mo)
22 dogs still alive
11 dogs deceased
8 for non-neurological diseases
3 euthanasia: insufficient improvement or complications
Patient Outcome
91% have shown improvement of at least 1+
neurological grade
Satisfactory to Excellent: 30 dogs
Unsatisfactory: 1 dog
Poor: 2 dogs
No Domino lesions during the observation
period
Better: mild and short duration of signs on presentation
Worse: chronic non-ambulatory paraparesis + extensor
rigidity of front legs not resolving under general
anesthesia
Clinical Assessment
42. Patch: 6 y old MN Dalmatian
6 mo ambulatory tetraparesis
worsening 2 mo prior to presentation
43. Sonny: 8 y old MN Doberman
1y ambulatory tetraparesis, acute tetraplegic
7 months post-op
45. Complications
Vertebral fissure fracture during distraction: 2 dogs
Improper Caspar pins placement
+/- excessive distraction with Caspar Distractor
Did not affect the outcome
Immediate subsidence: 1 dog
Improper technique: over-burring.
Surgical revision with dorsal laminectomy
Regained improvement
Subsidence: 7/50 disc spaces
Too thick and too narrow discs
Except for 1 dog, did not affect the outcome
Improper technique
46. Complications
Vertebral Axial Compression fracture: 1 dog
Nikkie
Sheltie Mix, F, 12.4 y old,
29 lb = 12.2 kg
History
4 years ambulatory ataxia,
6 month prior to referral non ambulatory tetraparesis
with extensor rigidity all 4 legs, not resolving under
anesthesia
Overdistraction
RDR 3.2 (normal > 1.7 and < 2)
2 weeks post-op
Pre-op
Immediate Post-op
C5 C6 C7
47. Complications
Nikkie
2 weeks post-op
Declined to non-ambulatory tetraparesis
Intense cervical pain
Radiography:
Suspected Axial compression fracture C6
Ventral implant migration
Euthanasia - no histopathology
• What went wrong?
• Dog’s size too small: 13.2 Kg
• Over-distraction
• Thinner discs sizes currently not available for these dog’s size
• Weak geriatric vertebrae (osteoporosis)!?
• Combination of the above
Poor patient selection
2 weeks post-op
2 weeks post-op
C5
C6
C7
48. Poor Outcome
2 dogs
Chow Mix, F, 13.5 y old
Doby, M, 12 y old
History
8-14 months progressive non ambulatory tetraparesis
Severe extensor rigidity all 4 legs, not resolving under anesthesia
Outcome:
Dog 1 (Chow): Euthanized 8 mo. after surgery d/t insufficient
improvement
Dog 2 (Doby): Neuro score improved only from 6 to 5
• What went wrong?
• Neurological signs too advanced / severe
• Irreversible spinal cord damage
Poor patient selection
Pierce Simon
49. Limitations of CDA:
Dog’s size
Patient under 23 Kg are not good candidates for
CDA
Underlying vertebral diseases
Weaker bone in geriatric dogs
In humans usually bone density test
Not good candidate for CDA
Prolonged history of non-ambulatory tetraparesis
Severe extensor rigidity of front legs not
resolving under general anesthesia
Overall: too severe / advanced neurological signs
Clinical Relevance
50. Advantages of CDA
Less invasive than traditional surgeries
Rapid post-surgical recovery
Can be performed on a out-patient basis
Treatment of multiple lesions at adjacent or non-adjacent sites
Prophylactically for “Incipient lesions”
May prevent “Domino lesions”
C7
C6
C5
51. Spinal cord decompression &
“dynamic stabilization”
Immediate relief of radicular pain
and vascular compression at the
intervertebral foramina
Enable MRI re-assessment
for complications
for long term re-assessment of
domino lesions
Other Benefits
C6 C7*
52. Disadvantages – Limitations
Concurrent Dorsal spinal compression
The possible decrease of distraction over
time may exacerbate the dorsal
compression
If concurrent dorsal compression, it
might be necessary to combine CDA
along with removal of the dorsal
compression at the affected site
53. Conclusions
CDA using this prosthesis appears to be safe
and effective
Suitable for medium and large breed dogs
Rapid post-surgical recovery
Ideal for treating multiple levels
Not technically difficult and easy to master
May prevent “Domino Lesions”
May improve pet-owner willingness to
pursue a surgical option
54. Conclusions
CDA is very promising for the treatment
of DAWS.
Case selection , Early Intervention and Correct
execution of the surgical technique may be critical
factors for the outcome
Case selection is King, technique is the Prince
Dr. Zelman column:
number 6 of the most commonly cited
attributes of a “great” surgeon
59. Disc size selection
Pre-operative
MRI measurement
Final assessment during surgery
60. CDA Surgery video - Clinical case
Inserire video – surgical technique
61. 3rd CDA Course
1. Questions ??
2. Break 10 min.
1. Dr. Kroll Lecture
1. Frequently Asked Questions
Dr. Adamo
2. Practice on spine specimens
Dr. Adamo, Dr. Kroll, Dr. Giovannella
3. Lunch
4. Practice on cadavers
64. a. Discectomy with deep cleaning of the end plates from
the annulus
b. Minor burring to accommodate the disc implant
1. Will I be performing a discectomy
or a ventral slot?
65. Just enough to create space for the disc implant.
a. The small burr is used for the initial burring and to create
enough space to insert the large burr.
b. The large burr is used for the final cleaning of the end-
plate, and to create enough space to accommodate the
disc in the discectomy site
c. Mild exposure of the cancellous bone in the center
area of the caudal vertebral endplate is acceptable and
often needed.
Small burr
Large burr
C5C6
2. How much do I have to burr?
67. Parallel to each other but at about a 30-degree angle away from the
midline and away from the side on which the surgeon is standing.
3. Which is the best position to place the
Caspar distractor pins?
68. Placing the pins too far from the affected disc space may cause
vertebral fracture during distraction.
Place the pins toward the center or caudal third in the cranial vertebral
body, and toward the center or cranial third of the caudal vertebral body
4. How can I prevent vertebral fracture
during Caspar distraction?
X
X
69. Place the pin toward the center of the vertebral body that will be
receiving the discectomies and the disc implants at both ends
5. In the event that two adjacent sites have to
be treated at the same time, what is the
best pin placement?
70. Until it becomes difficult to distract any more!
6. How much do I have to distract?
71. The widest and tallest disc size possible that fits in the
discectomy site.
The increased area of contact between the implant and the vertebral
end-plate, may decrease the degree of subsidence.
It is best to select the disc that fits firmly in the disc space but that
doesn’t cause excessive vertebral distraction; too much distraction
may increase subsidence.
7. Which disc size is best to use?
72. • Before closure, bone wax can be packed on the ventral
edges of each vertebra facing the external surface of the
implant.
8. How can I prevent ventral bridging
spondylosis and tissue ingrowth between
the two articulating faces of the implant?
73. A lateral, VD, and dynamic views in dorsi-flexion and ventro-
flexion
This to have a baseline to assess distraction and mobility on the
following serial post-operative radiographs
9. Which views should be included in the
immediate post-operative radiographs?
NEUTRAL
VENTRO-FLEXION V-D
DORSI-FLEXION
74. 2 weeks, 3, 6, 12 and 24 month follow-up
10. To evaluate distraction and mobility when is
recommended to perform serial post-op
radiographs?
NEUTRAL
VENTRO-FLEXION
DORSI-FLEXION
V-D
9 mo. Post-op:
- Maintained Mobility,
- Maintained Distraction,
- No Subsidence
75. Fracture of the vertebral body
• Weak bone in old dogs
• Excessive distraction (disc too thick)
• Using this implant in dogs < 23kg
Less likely to affect the outcome:
Osteophytes and Heterotopic Ossifications
Vertebral ankylosis
Spondylarthrosis
Loss of distraction and/or mobility
Minor Subsidence
11. Which one is the most serious complication
of CDA that may affect the clinical outcome?
2 weeks post-op
2 weeks post-op
C5
C6
C7
76. Not less than 23 kg
12. What is the recommended minimum patient
weight for the application of this prosthesis?
77. Leash walk until 3 month
radiographic re-check
Full activity after 6 months
radiographic re-check
3 mo. post-op
6 mo. post-op
13. For how long is activity restriction
recommended?
79. CDA Practice on spine specimens
Objective: Familiarization with the technique and instruments
(discs not treated with HA)
80. Wet-lab – CDA- guidelines
Implants used in this lab are not HA coated
10 cadavers
5 surgery stations x 2 times
3 participants in 3 stations
2 participants in 2 stations
Each participant will practice 2 CDA surgeries
The instructor will first show CDA at C3-4
Your disc spaces to practice are C4-5; C5-6 & C6-7
Name yourself #1, #2 and #3
On the first set cadavers: #1 C4-5; #2 C5-6; #3 C6-7
On the second set of cadavers #1 C6-7; #2 C4-5; #3
C5-6
Post-op Radiographs Discussion:
Remember on the 2nd cadaver: your dog number and the disc space
where you placed the implant
84. How to place the order
Allison Hsia: Events Assistant AVT
85. How to place the order
Special offer for attending the Course:
Total value of surgery kit: $ 15,260
Discount for attending the course: - $ 1,200
2 additional discs sizes of $1,500 value: Complimentary
Additional 10% discount for placing the
order within 30 days: - $ 1,406
---------------------------------------------------------------------
New Total $ 12,654
Cost of Shipment not included
86. Opportunity to promote and differentiate your practice
with an innovative surgical technique
Average surgery cost (surg. + anesthesia):$ 3,500
Mark up implant (x1.5 or x2): $ 1,000 - 1,500
Total cost of surgery: $ 4,500 -
5,000
Number of surgeries to recup. the investment: 3
Cost Analysis
87. How to place the order
For Full discount: place order within 30 days from
today.
Payment options:
Payment in full today and take the surgery kit home
Deposit $500 minimum and remaining balance before shipment
Guarantees one of the limited available surgery kits
To assemble a new surgery kit it may take up to 3 month from the
order.
Order can also be placed by contacting:
Preeti Zalavadia, pzal@appliedvt.com - Administrative Assistant
of AVT.