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

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.