• Device: prodisc C SK and/or Vivo
  Subjects will be randomized in a 2:1 ratio either to the two-level prodisc C SK or prodisc C Vivo device (investigational group) or to the two-level Mobi-C device (control group).
• Device: Mobi-C Cervical Disc
  Subjects will be randomized in a 2:1 ratio either to the two-level prodisc C SK or prodisc C Vivo device (investigational group) or to the two-level Mobi-C device (control group).

• Experimental: Investigational
  Two-level prodisc C SK and/or prodisc C Vivo
  Intervention: Device: prodisc C SK and/or Vivo
• Active Comparator: Control
  Two-level Mobi-C device
  Intervention: Device: Mobi-C Cervical Disc

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:

   1. Neck and/or arm pain (at least 30 mm on the 100 mm visual analogue scale [VAS] scale).
   2. Decreased muscle strength of at least one level on the clinical evaluation 0 to 5 scale.
   3. Abnormal sensation including hyperesthesia or hypoesthesia; and/or
   4. Abnormal reflexes.
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 including at least one of the following:

   1. Decreased disc height on radiography, computed tomography (CT), or magnetic resonance imaging (MRI) in comparison to a normal adjacent disc.
   2. Degenerative spondylosis on CT or MRI.
   3. Disc herniation on CT or MRI.
5. NDI Score of ≥ 30%

6. Unresponsive to non-operative, conservative treatment (rest, heat, electrotherapy, physical therapy, chiropractic care and/or analgesics) for:

   1. Approximately six weeks from radiculopathy or myelopathy with radiculopathy symptom onset; or
   2. Have the presence of progressive symptoms or signs of nerve root/spinal cord compression despite continued non-operative, conservative treatment; or
   3. Sooner than 6 weeks for worsening symptoms of neurologic compromise.

Exclusion Criteria:

1. Have an active systemic infection or infection at the operative site.
2. Have a history of or anticipated treatment for active systemic infection, including HIV or Hepatitis C.
3. 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.
4. Have previous trauma to the C3 to C7 levels resulting in significant bony or disco-ligamentous cervical spine injury.
5. Have had any prior spine surgery at the operative level(s).
6. Have had a prior cervical TDR or fusion procedure at any level.
7. Have axial neck pain in the absence of other symptoms of radiculopathy or myelopathy with radiculopathy justifying the need for surgical intervention.
8. Have disc height less than 3 mm as measured from the center of the disc in a neutral position and disc height less than 20% of the anterior-posterior width of the inferior vertebral body.
9. Have radiographic confirmation of severe facet joint disease or degeneration at any level.
10. Have osteoporosis or is at increased risk of osteoporosis defined as a DEXA bone density measured T-score of ≤ -1.5. A DEXA performed within 24 months of the surgery date may be used to determine eligibility. For subjects without a DEXA within 24 months of the surgery date a score ≥6 on either the SCORE or MORES requires a DEXA to determine eligibility.
11. 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.
12. Have Symptomatic Cervical Disc Disease or significant cervical spondylosis at more than two levels.

13. Have marked cervical instability on resting (neutral) lateral or flexion-extension radiographs demonstrated by:

    1. Translation ≥ 3.5 mm, and/or
    2. Greater than 11° angular difference to that of either adjacent level.
14. Have known allergies to cobalt, chromium, molybdenum, titanium, nickel or polyethylene.
15. Have segmental angulation of greater than 11° at treatment or adjacent levels.
16. Have rheumatoid arthritis, lupus, or other autoimmune disease that affect the musculoskeletal system.
17. Have congenital bony and/or spinal cord abnormalities that affect spinal stability.
18. Have concomitant conditions requiring daily, high-dose oral and/or inhaled steroids.
19. Have a Body Mass Index (BMI) > 40 kg/m2.
20. Taking medications known to potentially interfere with bone/soft tissue healing (e.g., high-dose oral and/or inhaled steroids, immunosuppressant medication, chemotherapeutic agents).
21. Have a current history of heavy smoking (more than one pack of cigarettes per day).
22. Have had an epidural steroid injection within 14 days prior to surgery.