Kineflex|C Artificial Disc System to Treat Cervical Degenerative Disc Disease (DDD)

Inclusion Criteria: * have symptoms of cervical degenerative disc disease (DDD) at only one cervical level from C3 to C7, disc herniation on CT or MRI; * have radiculopathy symptoms in neck, one or both shoulders, and/or one or both arms; * have at least six months of prior conservative treatment (e.g., physical therapy and/or use of anti-inflammatory medications and muscle relaxants at the manufacturer's recommended therapeutic dose), the presence of progressive symptoms (e.g., increasing numbness or tingling), or signs of nerve root compression; * have moderate disability neck disability index (NDI) score; AND * be likely to return for all follow-up visits and be willing and able to provide informed consent for study participation Exclusion Criteria: * marked cervical instability; * non discogenic neck pain or non discogenic source of symptoms; * radiographic confirmation of severe facet disease or facet degeneration; * bridging osteophytes; * prior surgery at the level to be treated; * prior fusion at any cervical level; * more than one neck surgery via anterior approach; * previous trauma to the C3-C7 levels resulting in compression or bursting; * documented presence of free nuclear fragment at any cervical level; * severe myelopathy; * any paralysis; * history of chemical or alcohol dependence; * active systemic infection; * infection at the site of surgery; * prior disc space infection or osteomyelitis in the cervical spine; * any terminal, systemic or autoimmune disease; * metabolic bone disease (e.g., osteoporosis, gout, osteomalacia, Paget's disease); * any disease, condition or surgery which might impair healing; * known metal allergy; * arachnoiditis; * currently experiencing an episode of major mental illness; * pregnancy at time of enrollment, or planning to become pregnant, since this would contraindicate surgery; * morbid obesity; use of spinal stimulator at any cervical level prior to surgery; * currently a prisoner; * currently involved in spinal litigation which may influence the subjects reporting of symptoms; OR * lives more than 300 miles from study center or participation in any other investigational drug, biologic, or medical device study within the last 30 days prior to study surgery