Prospective, Concurrently Controlled, Multi-Center Study to Evaluate the Safety and Effectiveness of the Spinal KineticsTM M6-C Artificial Cervical Disc Compared to Anterior Cervical Discectomy and Fusion (ACDF) for the Treatment of Symptomatic Cervical Radiculopathy

IRB Number: 2014-104

Institutional Review Board, Hospital for Special Surgery

February 25, 2015

The safety of study participants is our top priority. The trial is approved and periodically reviewed by an Institutional Review Board (IRB), which includes doctors, administrators, ethicists, and members of the general public. The safety of clinical trials is reviewed by the U.S. Food and Drug Administration.

Before enrolling in a clinical trial, the investigator will explain the purpose of the trial, its expected benefits, any possible risks or side effects, and what your role will be. This is the time to ask questions! If you want to join the trial, you must sign the informed consent documents. You can leave a clinical trial at any time without penalty.

For further information, see Understanding Clinical Trials.

Principal Investigator

Andrew A. Sama, MD


Todd J. Albert, MD
Federico P. Girardi, MD
Frank P. Cammisa, Jr., MD


This is a prospective, concurrently controlled, multi-center study to evaluate the safety and effectiveness of the Spinal Kinetics M6-C artificial cervical disc compared to anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical radiculopathy.  At the Hospital for Special Surgery, patients who qualify for the study will have the damaged disc in their neck removed and replaced with the M6-C disc. The M6-C is intended to act as a replacement for the patient’s natural disc.

Enrolled patients will be evaluated in their doctor’s office before surgery as well as after surgery (6 weeks, 3 months, 6 months, 1 year, and 2 years) with each visit taking approximately 1-2 hours. After the 2 year visit, patients may be asked to return annually for additional follow-up visits. A total of 243 subjects will be included in the study, with a total of 20 patients enrolled at the Hospital for Special Surgery.

Inclusion/Exclusion Criteria

Inclusion Criteria

  1. Diagnosis of degenerative cervical radiculopathy with or without spinal cord compression requiring surgical treatment at one level from C3 to C7 demonstrated by signs and/or symptoms of disc herniation and/or osteophyte formation (e.g. neck and/or arm pain, radiculopathy, etc.) and is confirmed by patient history and radiographic studies (e.g. MRI, CT, x-rays, etc.)
  2. Inadequate response to conservative medical care over a period of at least 6 weeks
  3. Neck Disability Index score of ≥ 30% (raw score of ≥ 15/50)
  4. Neck or arm pain VAS ≥ 4 on a scale of 0 to 10
  5. Willing and able to comply with the requirements of the protocol including follow-up requirements
  6. Willing and able to sign a study specific informed consent
  7. Skeletally mature and ≥ 18 years old and ≤ 75 years old

Exclusion Criteria

  1. More than one cervical level requiring surgery
  2. Previous anterior cervical spine surgery
  3. Axial neck pain as the solitary symptom
  4. Previous posterior cervical spine surgery (e.g., posterior element decompression) that destabilizes the cervical spine
  5. Advanced cervical anatomical deformity (e.g., ankylosing spondylitis, scoliosis) at the operative or adjacent levels
  6. Symptomatic facet arthrosis
  7. Less than 4º of motion in flexion/extension at the index level
  8. Instability as evidenced by subluxation > 3 mm at the index or adjacent levels as indicated on flexion/extension x-rays
  9. Advanced degenerative changes (e.g., spondylosis) at the index vertebral level as evidenced by bridging osteophytes, central disc height < 4mm and/or < 50% of the adjacent normal intervertebral disc, or kyphotic deformity > 11º on neutral x-rays
  10. Severe cervical myelopathy (i.e., Nurick's Classification > 2)
  11. Active systemic infection or infection at the operative site
  12. Co-morbid medical conditions of the spine or upper extremities that may affect the cervical spine neurological and/or pain assessment
  13. Metabolic bone disease such as osteoporosis that contradicts spinal surgery (for  females over 50 and males over 55 years old, or if the score on the Osteoporosis  Self-Assessment Test is < 2, a dual energy x-ray absorptiometry [DEXA scan] of the spine is required; if the bone mineral density T-score in the spine is ≤ -2.5 the  patient must be excluded)
  14. History of an osteoporotic fracture of the spine, hip or wrist
  15. History of an endocrine or metabolic disorder (e.g., Paget's disease) known to affect bone and mineral metabolism
  16. Taking medications that may interfere with bony/soft tissue healing including chronic steroid use
  17. Known allergy to titanium, stainless steels, polyurethane, polyethylene, or ethylene oxide residuals
  18. Rheumatoid arthritis or other autoimmune disease or a systemic disorder such as HIV, active hepatitis B or C or fibromyalgia
  19. Insulin-dependent type 1 or type 2 diabetes
  20. Medical condition (e.g., unstable cardiac disease, cancer) that may result in patient death or have an effect on outcomes prior to study completion
  21. Pregnant, or intend to become pregnant, during the course of the study
  22. Severe obesity (Body Mass Index > 40)
  23. Physical or mental condition (e.g., psychiatric disorder, senile dementia, Alzheimer's disease, alcohol or drug addiction) that would interfere with patient self-assessment of function, pain or quality of life.
  24. Involved in current or pending spinal litigation where permanent disability benefits are being sought
  25. Incarcerated at the time of study enrollment
  26. Current participation in other investigational study that may impact study outcomes

Contact Information

Celeste Abjornson, PhD

Jennifer Shue, MS