Inclusion Criteria:

• 18-60 years of age (inclusive and skeletally mature)
• Diagnosis of symptomatic cervical disc disease, defined as image- confirmed pathology: herniated disc, spondylosis, and/or loss of disc height. Spondylosis is defined as MRI or CT-confirmed disc dessication, loss of disc height, bridging osteophytes, and/or uncovertebral arthrosis. Loss of disc height is specified as a measurement of at least 25% less than an adjacent nonsymptomatic level, but with a minimum of 1mm height remaining.
• Functional neurological deficit (i.e., exhibits at least one sign associated with cervical level to be treated, including abnormal reflex, decreased motor strength, abnormal dermatome sensitivity, or pain in a dermatomal distribution)
• Symptomatic level is C3-4, C4-5, C5-6 or C6-7 (one level)
• Preop NDI ≥30 points
• Unresponsive to conservative treatment for ≥6 wks, or exhibits progressive symptoms or signs of nerve root or spinal cord compression in the face of conservative treatment
• Not pregnant, nor interested in becoming pregnant within the follow-up period of the study
• Willing and able to comply with the requirements defined in the protocol for the duration of the study
• Signed and dated Informed Consent

Exclusion Criteria:

• Prior cervical fusion surgery at the operative level
• Prior cervical laminectomy at the operative level (prior cervical laminotomy need not be excluded)
• Prior cervical complete facetectomy at the operative level
• Requiring surgical treatment that would leave the patient with a postoperative deficiency of the posterior elements
• Radiographic signs of significant instability at operative level (greater than 3mm translation, > 11 degrees rotation different from adjacent level)
• Bridging osteophytes or motion < 2 degrees
• Radiographic confirmation of significant facet joint disease or degeneration
• Chronic neck or arm pain of unknown etiology
• Clinically significant symptomatic myelopathy (e.g., those with signal changes in the spinal cord on preoperative T2-weighted MRI)
• Cervical fracture, anatomic anomaly, or deformity (e.g. ankylosing spondylitis, scoliosis) at the levels to which the prosthesis will be attached
• Severe spondylolisthesis (>grade 1)
• Endocrine disorders or connective tissue diseases
• Rheumatoid arthritis or other autoimmune disease
• Progressive neuromuscular disease, e.g., muscular dystrophy, multiple sclerosis
• Chronic steroid users
• Taking any medications or drugs that are known to potentially interfere with the bone metabolism or soft tissue healing, which may include (but is not limited to) the following: inhaled glucocorticoids for asthma, corticosteroids, thyroid hormones, blood thinners (heparin, warfarin), gonadotropin-releasing hormone agonists for prostate cancer treatment, contraceptive medroxyprogesterone, lithium for bi-polar disorder treatment, anticonvulsants, aluminum-containing antacids, tetracycline
• Osteopenia, osteoporosis, or osteomalacia to a degree that spinal instrumentation would be contraindicated (DEXA T-score less than or equal to -2.5; DEXA necessary only if patient exhibits risk factors for low bone mass as quantified in DEXA screening questionnaire).
• Diabetes mellitus requiring insulin management
• Presence of metastases or active spinal tumor malignancy
• Body Mass Index (BMI) > 40
• Active local or systemic infection, including AIDS, hepatitis
• Having been enrolled in another investigational device study within the last 90 days
• Having had another cervical device implanted that would interfere with the surgical approach, study or control device, or follow-up evaluations.
• Demonstrates signs of nonorganic behavior, such as Waddell's signs
• History of substance abuse
• Involved in spinal litigation
• Mentally incompetent
• Incarcerated