1. Introduction to Spine Arthroplasty Ira Fedder, MD Scoliosis and Spine Center Towson, MD
DePuy Spine confidential information. Do not duplicate. Do not distribute.

2. Spine Surgery at the Millennium
Posterolateral +/- Instrumentation
Circumferential (“360°”)
PLIF (Posterior Lumbar Interbody Fusion)
ALIF (Anterior Lumbar Interbody Fusion)
TLIF (Transforaminal Lumbar Interbody Fusion)

3. Paradox
Can the same problem (discogenic pain) be treated effectively using interventions with the exact opposite technical goals?

4. 80% Anterior 20% Posterior Biomechanics
The rule of Spine loading

5. History of Lumbar TDR
Fernström – 1960’s

6. History of Lumbar TDR
Synthes™
PRODISC® I
PRODISC® II

7. History of Lumbar TDR
Medtronic™
Maverick™

8. History Karin Büttner-Janz INVENTOR
DePuy Spine confidential information. Do not duplicate. Do not distribute.

9. History of Lumbar TDR
SB CHARITÉ™ I II
III

10. History Design Iterations
Experimental Prototypes Never Commercially Available
Inventors Drs. Schellnack and Büttner-Janz
SB Charité™ I
1984
13 patients, 14 Implants
SB Charité ™ II
1985
36 patients, 44 Implants
Non-forged stainless steel
No special instrumentation
Data from The Artificial Disc, Buttner-Janz, 2003

11. History - Current Design CHARITÉ Artificial Disc
Refined design by Waldemar Link
Cast Cobalt Chrome Endplates
Ultra High Molecular Weight Polyethylene (UHMWPE) Sliding Core
Design unchanged since 1987
First released 1987
Thousands of implantations worldwide
Same design used in U.S. IDE clinical study
17-year track record

12. Design Rationale Comprised of 3 Components
2 Cobalt Chrome (CoCr) Endplates
1 UHMWPE Sliding Core
Mobile-bearing technology
Concave Endplates
Convex Sliding-Core

13. Design Rationale Footprint Sizes2 3 4 5

14. Intra-Operative Modularity
Design Rationale
Combinations
Lordotic angles 0°
0°+ 0 ° 5°
0°+ 5 °
7.5°
0°+ 7.5 ° 0°
7.5°
10°+ 0 °
or 5° + 5°
10°
12.5°
7.5° + 5°
7.5° + 7.5° or 10° + 5°
15° 5°
10°
17.5°
10° + 7.5°
Intra-Operative Modularity
20°
10° + 10°

15. Design Rationale
2.5mm H
Sliding Core Heights H

16. Importance of Sizing Bone Density Proper Endplate Size
Dr. Wolfgang Raushning - Uppsala University, Sweden 2000

17. David, TJ. Results related to surgeon experience 1989 - 1991
“Lumbar Disc Prosthesis: Five Years Follow-up Study on 147 Patients with 163 SB Charité Prosthesis.” EuroSpine 2003
Results related to surgeon experience
43 patients: 63% excellent/good
57 patients: 82% excellent/good
44 patients: 93% excellent/good
Note that outcomes improved over time. By 1997 outcomes were at 93%. This speaks to the need for training. Increasingly superior results correlates with identification of the proper indications, the appropriate patient, the availability of more implant sizes and refinement of the surgical technique and instrumentation. Of additional note is that the U.S. trial was conducted with the during the latter date ranges using the improved instrumentation and refined surgical technique thereby incorporating the learning experience of the European surgeons into the trial.

18. European Experience: Lessons Learned
Sizing
Positioning
Patient selection
Controlled distraction

19. Learning Objectives
Patient Selection

20. Radiographic Evaluation
We ARE treating discogenic pain with TDR
Biggest challenge is to identify the pain generator
Start with plain x-rays, MRI
Studies have shown high false positive rate of MRIs
Discography can help distinguish between asymptomatic “dark discs” on MRI and those that are pain generators

21. Discography Clinical pain provocation test Radiographic images
Test is positive only if:
The disc is abnormal in appearance
AND
Patient’s clinical pain is provoked during injection

22. Clinical Indications Chronic low back pain +/- leg pain Leg pain
Persisting > 6 months
Associated with degenerative disc changes
Leg pain
Radicular
Pseudoradicular
Foraminal stenosis
Secondary to disc space height loss
may be relieved indirectly by disc height restoration

23. Osteoporosis or Osteopenia
Contraindications
Osteoporosis or Osteopenia
Dexa-scan patients > age 50 or with more than 1 risk factor
T< is contraindicated

24. Contraindications
Scoliosis >11º sagital deformity

25. Contraindications Instability including isthmic spondylolysis
spondylolisthesis
retro or anteriolisthesis > 3mm

26. Contraindications Poor psychometric evaluation Abnormal pain discogram
Hz of Schizophrenia
Bi-polar condition
Severe depression
Inability to comprehend procedure and risks

27. Facet Disease? Widened joint diagnostic for instability:
Degenerative Spondy

28. Facet Disease Contraindication: Advanced Facet Disease
Mild
Moderate
Severe
Contraindication:
Advanced Facet Disease
Severe Spinal Stenosis (canal space < 8mm)
Use CT Myelogram to evaluate

29. Contraindications Pregnancy Central Stenosis
Single or bilateral leg pain (due to nerve compression)
Non-contained herniated nucleus pulposus
Infection/neoplasm
Autoimmune disorders
Central Stenosis
Tumor
Arachnoiditis
History of chronic steroid use
Advanced facet disease
Facet joint ankylosis
Metal allergies

30. Approach Related Contraindications
Anterior Vascular Calcification
Previous major vessel surgery
Obesity: BMI > 40 or 100lbs over ideal body weight
Previous retroperitoneal procedures

31. Handling Vascular Complications
Control:
One can often get proximal and distal control with pressure against the spine using peanut or sponge on a stick
Hemoclips:
Use a row of hemoclips along injured edge of vein rather than try to sew in a small deep wound
Cell Saver:
Typically cell saver is not used routinely unless an injury occurs

32. Spine Surgeons: Tips To Avoid Complications
Cut the annulus
Clean side to side
Remain in the space
Beware of cautery conduction
Be aware of the vessels
Always check clearances before using Spreading and Insertion Forceps
Lateral clearance
Superior / Inferior clearance
Maintain vascular clearance

33. Effectiveness Results (All Randomized)
Primary Hypothesis: Overall Success Rate
Conclusion: The CHARITÉ Artificial Disc is at least equivalent in overall success to the BAK cage in treatment of DDD at one level (L4-S1).
Small P-value indicates high degree of certainty

34. Effectiveness Results (All Randomized)
Primary Effectiveness Endpoints
* re-operation, revision, removal or additional fixation
** major vessel injury, neurological damage or nerve root injury

35. Implant Lateral X-Ray Final
Center of rotation 2mm dorsal sagital midline maximum footprint coverage – proper lordotic angles

36. Implant A/P X-Ray Final
Center spike positioned on A/P midline

37. Final Position

38. Final AP & Lateral Position