The Synergy Disc for the Treatment of 2 Level Cervical Degenerative Disc Disease Compared With Cervical Fusion Surgery

Inclusion Criteria:

In order to be eligible to participate in this study, subjects must meet all of the following criteria:

1. Must be at least 18 years of age and be skeletally mature at the time of surgery

2. Has a preoperative neck pain score ≥ 8 (out of 20) based on the preoperative Neckand Arm Pain Questionnaire.

3. Has cervical degenerative disc disease at two (2) adjacent cervical levels (from C3

• C7) requiring surgical treatment and involving intractable radiculopathy,myelopathy, or both;

4. Has a herniated disc and/or osteophyte formation at each level to be treated that isproducing symptomatic nerve root and/or spinal cord compression. The condition isdocumented by patient history (e.g., neck pain with arm pain, functional deficitand/or neurological deficit), and the requirement for surgical treatment isevidenced by radiographic studies (e.g., CT, MRI, x-rays, etc.);

5. Neck Disability Index (NDI) score ≥ 30/100 (raw score of ≥ 15/50);

6. Has been unresponsive to non-operative treatment for at least six weeks or has thepresence of progressive symptoms or signs of nerve root/spinal cord compression inthe face of continued non-operative management; has no previous surgicalintervention at the involved levels or any subsequent planned/staged surgicalprocedure at the involved or adjacent level(s);

7. If a female of childbearing potential, patient is non-pregnant, non-nursing, andagrees not to become pregnant during the study period;

8. Is willing to comply with the study plan and sign the Patient Informed Consent Form

Exclusion Criteria:

Subjects who meet any of the following criteria will be excluded from participation in this study:

1. Has a cervical spinal condition other than symptomatic cervical DDD requiringsurgical treatment at the involved levels;

2. Has documented or diagnosed cervical instability relative to adjacent segments ateither level, defined by dynamic (flexion/extension) radiographs showing:

3. Sagittal plane translation > 3.5 mm, or

4. Sagittal plane angulation > 20°;

5. Prior attempted or completed cervical spine surgery, except (1) laminoforaminotomy (greater than 6 months prior to scheduled surgical treatment), which includesremoval of disc material necessary to perform a nerve root decompression, with lessthan one-third facetectomy at any level, or (2) a successful single-level anteriorcervical fusion (greater than 6 months prior to scheduled surgical treatment);

6. Has severe pathology of the facet joints of the involved vertebral bodies;

7. Axial neck pain only (no radicular or myelopathy symptoms);

8. Has been previously diagnosed with osteomalacia;

9. Osteoporosis: A screening questionnaire for osteoporosis, SCORE (Simple CalculatedOsteoporosis Risk Estimation) for females or MORES for males (Male Osteoporosis RiskEstimation Score), will be used to screen patients to determine those patients whorequire a DXA of the hip, a bone mineral density measurement. A SCORE or MORES ≥6requires a DXA. If DXA is required, exclusion will be defined as a DXA bone densitymeasured T score ≤ -2.5 (The World Health Organization definition of osteoporosis).DXA scans within the last 6 months prior to surgical treatment may be used;

10. Has presence of spinal metastases;

11. Has overt or active bacterial infection, either local or systemic;

12. Has insulin-dependent diabetes;

13. Has chronic or acute renal failure or prior history of renal disease;

14. Known titanium or UHMWPE allergy;

15. Is mentally incompetent (if questionable, obtain psychiatric consult);

16. Is a prisoner;

17. Is pregnant ;

18. Is currently an alcohol and/or drug abuser or currently undergoing treatment foralcohol and/or drug abuse;

19. Is involved with current or pending litigation regarding a spinal condition;

20. Has received drugs that may interfere with bone metabolism within two weeks prior tothe planned date of spinal surgery (e.g., steroids or methotrexate), excludingroutine perioperative anti-inflammatory drugs;

21. Has a history of an endocrine or metabolic disorder known to affect osteogenesis (e.g., Paget's Disease, renal osteodystrophy, Ehlers-Danlos Syndrome, orosteogenesis imperfecta);

22. Has a condition that requires postoperative medications that interfere with thestability of the implant, such as steroids. This does not include low-dose aspirinfor prophylactic anticoagulation and routine perioperative anti-inflammatory drugs;

23. Has received treatment with an investigational therapy within 28 days prior toimplantation surgery or such treatment is planned during the 16 weeks followingimplantation