Investigation of the Two Level Simplify® Cervical Artificial Disc

Inclusion Criteria

• Has cervical degenerative disc disease at two (2) adjacent cervical levels (from C3 C7) requiring surgical treatment and involving intractable radiculopathy, myelopathy, or both;
• Has a herniated disc and/or osteophyte formation at each level to be treated that is producing symptomatic nerve root and/or spinal cord compression. The condition is documented by patient history (e.g., neck pain with arm pain, functional deficit and/or neurological deficit), and the requirement for surgical treatment is evidenced by radiographic studies (e.g., CT, MRI, x-rays, etc.);
• Has been unresponsive to non-operative treatment for at least 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;
• Has no previous surgical intervention at the involved levels or any subsequent planned/staged surgical procedure at the involved or adjacent level(s);
• Must be at least 18 years of age and be skeletally mature at the time of surgery;
• Has a preoperative Neck Disability Index (NDI) ≥ 30;
• Has a preoperative neck pain score > 8 based on the preoperative Neck and Arm Pain Questionnaire;
• If a female of childbearing potential, patient is non-pregnant, non-nursing, and agrees not to become pregnant during the study period;
• Is willing to comply with the study plan and sign the Patient Informed Consent Form.

Exclusion Criteria

• Has a cervical spinal condition other than symptomatic cervical DDD requiring surgical treatment at the involved levels;
• Has documented or diagnosed cervical instability relative to adjacent segments at either level, defined by dynamic (flexion/extension) radiographs showing:
• Sagittal plane translation > 3.5 mm, or
• Sagittal plane angulation > 20°;
• Has more than two cervical levels requiring surgical treatment;
• Has a fused level (or artificial disc replacement) adjacent to the levels to be treated;
• Has severe pathology of the facet joints of the involved vertebral bodies;
• Has had previous surgical intervention at either one or both of the involved levels or at adjacent levels;
• Axial neck pain only (no radicular or myelopathy symptoms);
• Has been previously diagnosed with osteopenia or osteomalacia;
• 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):
• Postmenopausal non-black female over 60 years of age who weighs less than 140 pounds;
• Postmenopausal female who has sustained a non-traumatic hip, spine, or wrist fracture;
• Male over the age of 70;
• Male over the age of 60 who has sustained a non-traumatic hip or spine fracture.
• If the level of bone mineral density is a T score of -1.5 or lower (i.e., -1.6, 1.7, etc.), then the patient is excluded from the study
• Has presence of spinal metastases;
• Has overt or active bacterial infection, either local or systemic;
• Has insulin-dependent diabetes;
• Has chronic or acute renal failure or prior history of renal disease;
• Known PEEK, ceramic, titanium allergy;
• Is mentally incompetent (if questionable, obtain psychiatric consult);
• Is a prisoner;
• Is pregnant;
• Is currently an alcohol and/or drug abuser or currently undergoing treatment for alcohol and/or drug abuse;
• Is involved with current or pending litigation regarding a spinal condition;
• Has received drugs that 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;
• 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);
• Has a condition that requires postoperative medications that interfere with the stability of the implant, such as steroids. (This does not include low-dose aspirin for pr