A multi-center, prospective, randomized, controlled comparison of the prodisc C SK and prodisc C Vivo to the control, a similar, legally marketed total disc replacement device in subjects with symptomatic cervical disc disease (SCDD).

The clinical trial is to demonstrate that prodisc C SK and prodisc C Vivo are at least as safe and effective as a similar, currently marketed cervical disc prosthesis to treat symptomatic cervical disc disease (SCDD) in subjects at two contiguous levels from C3 to C7 who are unresponsive to conservative management. Subjects will be randomized in a 2:1 ratio to either the two-level prodisc C SK or prodisc C Vivo device (investigational group) or to the two-level Mobi-C device (control group). Subjects will be followed for at least 2 years and up to 5 years. Subjects will be required to complete subject questionnaires, have X-rays and undergo neurological assessments during the follow up visits as specified in the protocol.

Inclusion Criteria:

1. Age ≥18 and ≤69 years.
2. Diagnosis of radiculopathy or myelopathy with radiculopathy of the cervical spine, with pain, paresthesias or paralysis in a specific nerve root distribution C3 through C7, including at least one of the following:
3. Symptomatic cervical disc disease (SCDD) at two contiguous levels from C3 to C7.
4. Radiographically determined pathology at the level to be treated correlating to primary symptoms.
5. Unresponsive to non-operative, conservative treatment (rest, heat, electrotherapy, physical therapy, chiropractic care and/or analgesics)

Exclusion Criteria:

1. Have more than one immobile vertebral level between C1 to C7 from any cause including but not limited to congenital abnormalities and osteoarthritic "spontaneous" fusions.
2. Have previous trauma to the C3 to C7 levels resulting in significant bony or disco-ligamentous cervical spine injury.
3. Have had a prior cervical TDR or fusion procedure at any level.
4. Have osteoporosis or is at increased risk of osteoporosis
5. Have active malignancy that included a history of any invasive malignancy (except non-melanoma skin cancer), unless the subject had been treated with curative intent and there had been no clinical signs or symptoms of the malignancy for at least 5 years.
6. Have known allergies to cobalt, chromium, molybdenum, titanium, nickel or polyethylene.
7. Have rheumatoid arthritis, lupus, or other autoimmune disease that affect the musculoskeletal system.
8. Have concomitant conditions requiring daily, high-dose oral and/or inhaled steroids.
9. Have a Body Mass Index (BMI) > 40 kg/m2.
10. Taking medications known to potentially interfere with bone/soft tissue healing (e.g., high-dose oral and/or inhaled steroids, immunosuppressant medication, chemotherapeutic agents).
11. Have a current history of heavy smoking (more than one pack of cigarettes per day).

Patient is blinded to their treatment randomization until after surgery.