The purpose of this clinical investigation is to evaluate the safety and effectiveness of the ACD in the single level surgical treatment of patients with symptomatic cervical degenerative disc disease. The primary follow-up information obtained from this clinical investigation are used to support a PMA application for the ACD.

Inclusion Criteria:

All patients participating in this study must meet all of the following inclusion criteria:

1. Cervical degenerative disc disease defined as:

   intractable radiculopathy and/or myelopathy with at least one of the following items producing symptomatic nerve root and/or spinal cord compression which is documented by patient history (e.g., neck and/or arm pain], functional deficit, and/or neurological deficit, and radiographic studies (e.g., CT, MRI, x-rays, etc).

   1. herniated disc;
   2. osteophyte formation;

2. One cervical level requiring surgical treatment;

3. C3-C4 disc to C6-C7 disc level of involvement;

4. Unresponsive to non-operative treatment for approximately six weeks or has the presence of progressive symptoms or signs of nerve root/spinal cord compression in the face of continued non-operative management;

5. No previous surgical intervention at the involved level or any subsequent, planned/staged surgical procedure at the involved or adjacent level(s);

6. Is at least 18 years of age, inclusive, at the time of surgery;

7. Preoperative Neck Disability Index score > or = 30;

8. Has a preoperative neck pain score of > 20 based on the Preoperative Neck and Arm Pain Questionnaire.

9. If of child-bearing potential, patient is not pregnant at the time of surgery;

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

Exclusion Criteria:

A patient meeting any of the following criteria is to be excluded from the study:

1. Has a cervical spinal condition other than symptomatic cervical disc disease requiring surgical treatment at the involved level;

2. Documented or diagnosed cervical instability defined by dynamic (flexion/extension) radiographs showing:

   1. Sagittal plane translation > 3.5 mm or;
   2. Sagittal plane angulation > 20.

3. More than one cervical level requiring surgical treatment;

4. Has a fused level adjacent to the level to be treated;

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

6. Previous surgical intervention at the involved level;

7. Has been previously diagnosed with osteopenia or osteomalacia;

8. Has any of the following that may be associated with a diagnosis of osteoporosis (if Yes to any of the below risk factors, a DEXA Scan will be required to determine eligibility):

   1. Postmenopausal Non-Black female over 60 years of age and weighs less than 140 pounds.
   2. Postmenopausal female that has sustained a non-traumatic hip, spine, or wrist fracture.
   3. Male over the age of 70.
   4. Male over the age of 60 that has sustained a non-traumatic hip or spine fracture.

   If the level of BMD is a T score of -3.5 or a T score of -2.5 with vertebral crush fracture, then the patient is excluded from the study.

9. Has presence of spinal metastases;

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

11. Has severe insulin dependent diabetes;

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

13. Has fever (temperature > 101 F oral) at the time of surgery;

14. Has a documented allergy or intolerance to stainless steel, titanium, or a titanium alloy;

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

16. Is a prisoner;

17. Is pregnant;

18. Is an alcohol and/or drug abuser as defined by currently undergoing treatment for alcohol and/or drug abuse;

19. Has received drugs which may interfere with bone metabolism within two weeks prior to the planned date of spinal surgery (e.g., steroids or methotrexate), excluding routine perioperative anti-inflammatory drugs;

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

21. Has a condition that requires postoperative medications that interfere with the stability of the implant or fusion, such as steroids. (This does not include low dose aspirin for prophylactic anticoagulation and routine perioperative anti-inflammatory drugs);

22. Has received treatment with an investigational therapy within 28 days prior to implantation surgery or such treatment is planned during the16 weeks following Artificial Cervical Disc implantation.