M6-C Artificial Cervical Disc Two-Level IDE Pivotal Study

Inclusion Criteria: * Diagnosis of degenerative cervical radiculopathy with or without spinal cord compression requiring surgical treatment at two contiguous levels from C3 to C7 demonstrated by signs and/or symptoms of disc herniation and/or osteophyte formation (e.g. neck and/or arm pain, radiculopathy, etc.) and is confirmed by patient history and radiographic studies (e.g. MRI, CT, x-rays, etc.) * Inadequate response to conservative medical care over a period of at least 6 weeks or have the presence of progressive symptoms or signs of nerve root/spinal cord compression in the face of continued non-operative management * Neck Disability Index score of ≥ 30% (raw score of ≥ 15/50) * Neck or arm pain Visual Analog Scale Score ≥ 4 on a scale of 0 to 10 * Willing and able to comply with the requirements of the protocol including follow-up requirements * Willing and able to sign a study specific informed consent * Skeletally mature and at least 18 years old but not older than 75 years old Exclusion Criteria: * More than two cervical levels requiring surgery, or two non-contiguous levels requiring surgery * Previous anterior cervical spine surgery * Axial neck pain as the solitary symptom * Previous posterior cervical spine surgery (such as a posterior element decompression) that destabilizes the cervical spine * Advanced cervical anatomical deformity (such as ankylosing spondylitis, scoliosis) at either of the operative levels or adjacent levels * Symptomatic facet arthrosis * Less than four degrees of motion in flexion/extension at either of the index levels * Instability as evidenced by subluxation greater than 3 millimeters at either of the index or adjacent levels as indicated on flexion/extension x-rays. * Advanced degenerative changes (e.g., spondylosis) at either of the index vertebral levels as evidenced by bridging osteophytes, central disc height less than 4 millimeters and/or \< 50% of the adjacent normal intervertebral disc, or kyphotic deformity \> 11 degrees on neutral x-rays * Severe cervical myelopathy (i.e., Nurick's Classification greater than 2) * Active systemic infection or infection at the operative site * Co-morbid medical conditions of the spine or upper extremities that may affect the cervical spine neurological and/or pain assessment * Metabolic bone disease such as osteoporosis that contradicts spinal surgery * History of an osteoporotic fracture of the spine, hip or wrist * History of an endocrine or metabolic disorder (e.g. Paget's disease) known to affect bone and mineral metabolism * Taking medications that may interfere with bony/soft tissue healing including chronic steroid use * Known allergy to titanium, stainless steels, polyurethane, polyethylene, or ethylene oxide residuals * Fibromyalgia, Rheumatoid Arthritis (or other autoimmune disease), or a systemic disorder such as HIV or acute hepatitis B or C. * Insulin dependent diabetes * Medical condition (e.g., unstable cardiac disease, cancer) that may result in patient death or have an effect on outcomes prior to study completion * Pregnant, or intend to become pregnant, during the course of the study * Severe obesity (Body Mass Index greater than 45) * Physical or mental condition (e.g. psychiatric disorder, senile dementia, Alzheimer's disease, alcohol or drug addiction) that would interfere with patient self-assessment of function, pain or quality of life. * Involved in current or pending spinal litigation where permanent disability benefits are being sought. * Incarcerated at time of study enrollment * Current participation in other investigational study.