Investigation of the Two Level Simplify® Cervical Artificial Disc

This study is intended to demonstrate that the Simplify® Cervical Artificial Disc (Simplify® Disc) is at least as safe and effective as conventional anterior cervical discectomy and fusion (ACDF) when used to treat two contiguous discs from C3 to C7 following discectomy at two contiguous levels for intractable radiculopathy (arm pain and/or a neurological deficit) with neck pain or myelopathy due to abnormalities localized to the levels of the two contiguous disc spaces in subjects who are unresponsive to conservative management.

The objective of this clinical study is to evaluate the safety and effectiveness of the two-level Simplify® Disc compared to conventional two-level ACDF in skeletally mature patients for reconstruction of two contiguous discs from C3 to C7 following discectomy at two contiguous levels for intractable radiculopathy (arm pain and/or a neurological deficit) with neck pain or myelopathy due to abnormalities localized to the levels of the two contiguous disc spaces that are unresponsive to conservative management.

Eligibility Criteria:
Inclusion Criteria:

* Has cervical degenerative disc disease at two (2) adjacent cervical levels (from C3 C7) requiring surgical treatment and involving intractable radiculopathy, myelopathy, or both;
* Has a herniated disc and/or osteophyte formation at each level to be treated that is producing symptomatic nerve root and/or spinal cord compression. The condition is documented by patient history (e.g., neck pain with arm pain, functional deficit and/or neurological deficit), and the requirement for surgical treatment is evidenced by radiographic studies (e.g., CT, MRI, x-rays, etc.);
* Has been unresponsive to non-operative treatment for at least six weeks or has the presence of progressive symptoms or signs of nerve root/spinal cord compression in the face of continued non-operative management;
* Has no previous surgical intervention at the involved levels or any subsequent planned/staged surgical procedure at the involved or adjacent level(s);
* Must be at least 18 years of age and be skeletally mature at the time of surgery;
* Has a preoperative Neck Disability Index (NDI) ≥ 30;
* Has a preoperative neck pain score \> 8 based on the preoperative Neck and Arm Pain Questionnaire;
* If a female of childbearing potential, patient is non-pregnant, non-nursing, and agrees not to become pregnant during the study period;
* Is willing to comply with the study plan and sign the Patient Informed Consent Form.

Exclusion Criteria:

* Has a cervical spinal condition other than symptomatic cervical DDD requiring surgical treatment at the involved levels;
* Has documented or diagnosed cervical instability relative to adjacent segments at either level, defined by dynamic (flexion/extension) radiographs showing:

  * Sagittal plane translation \> 3.5 mm, or
  * Sagittal plane angulation \> 20°;
* Has more than two cervical levels requiring surgical treatment;
* Has a fused level (or artificial disc replacement) adjacent to the levels to be treated;
* Has severe pathology of the facet joints of the involved vertebral bodies;
* Has had previous surgical intervention at either one or both of the involved levels or at adjacent levels;
* Axial neck pain only (no radicular or myelopathy symptoms);
* Has been previously diagnosed with osteopenia or osteomalacia;
* Has any of the following that may be associated with a diagnosis of osteoporosis (if "Yes" to any of the below risk factors, a DEXA Scan will be required to determine eligibility):

  * Postmenopausal non-black female over 60 years of age who weighs less than 140 pounds;
  * Postmenopausal female who has sustained a non-traumatic hip, spine, or wrist fracture;
  * Male over the age of 70;
  * Male over the age of 60 who has sustained a non-traumatic hip or spine fracture.
  * If the level of bone mineral density is a T score of -1.5 or lower (i.e., -1.6, 1.7, etc.), then the patient is excluded from the study
* Has presence of spinal metastases;
* Has overt or active bacterial infection, either local or systemic;
* Has insulin-dependent diabetes;
* Has chronic or acute renal failure or prior history of renal disease;
* Known PEEK, ceramic, titanium allergy;
* Is mentally incompetent (if questionable, obtain psychiatric consult);
* Is a prisoner;
* Is pregnant;
* Is currently an alcohol and/or drug abuser or currently undergoing treatment for alcohol and/or drug abuse;
* Is involved with current or pending litigation regarding a spinal condition;
* Has received drugs that may interfere with bone metabolism within two weeks prior to the planned date of spinal surgery (e.g., steroids or methotrexate), excluding routine perioperative anti-inflammatory drugs;
* Has a history of an endocrine or metabolic disorder known to affect osteogenesis (e.g., Paget's Disease, renal osteodystrophy, Ehlers-Danlos Syndrome, or osteogenesis imperfecta);
* Has a condition that requires postoperative medications that interfere with the stability of the implant, such as steroids. (This does not include low-dose aspirin for prophylactic anticoagulation and routine perioperative anti-inflammatory drugs);
* Has received treatment with an investigational therapy within 28 days prior to implantation surgery or such treatment is planned during the 16 weeks following implantation.