Evaluation of the Safety and Effectiveness of the CORUS™ Posterior Cervical Stabilization System 3D (PCSS 3D) for the Treatment of 2-level Cervical Degenerative Disease

Degenerative disc disease (DDD) of the neck occurs when the discs between the bones of the spine wear down over time. These discs normally act as cushions and help the neck move. When they break down, the space between the bones can narrow and put pressure on nearby nerves or the spinal cord. This can cause pain in the neck, shoulders, and arms.

One common surgical treatment is called Anterior Cervical Discectomy and Fusion (ACDF). In this procedure, the surgeon approaches the spine from the front of the neck, removes the damaged disc, relieves pressure on the nerves, and fuses the bones together. Another option is Posterior Cervical Fusion (PCF), which is done from the back of the neck. In some cases, both procedures are combined to provide more stability and support healing. The purpose of this study is to evaluate whether combining ACDF and PCF leads to better outcomes than ACDF alone in patients with two-level cervical degenerative disc disease.

Participants in this study will be assigned to one of two groups:

One group will receive ACDF alone (standard treatment) The other group will receive a combination of ACDF and PCF (investigational treatment) The main goal of the study is to compare how well the bones fuse together in each group at 12 months after surgery. The study will assess whether the combined approach (ACDF + PCF) results in a higher rate of successful fusion compared to ACDF alone.

Inclusion criteria

• At least 18 years of age (Skeletally Mature)
• Indicated for ACDF treatment of degenerative disc disease (DDD) between and including C3-C7 at 2 contiguous levels as determined by the following:

• diagnosis of radiculopathy, myelopathy or myeloradiculopathy of the cervical spine, with pain, including at least one of the following: i. Neck and/or arm pain, ii. Decreased muscle strength, and iii. Abnormal sensation including hyperesthesia or hypoesthesia; and/or Abnormal reflexes.
• radiographically determined pathology at the levels to be treated correlating to primary symptoms including at least one of the following: i. Decreased disc height on radiography, computed tomography (CT), or magnetic resonance imaging (MRI) in comparison to a normal adjacent disc, ii. Degenerative spondylosis on MRI, and iii. Disc herniation on MRI.
• NDI Score of ≥ 15/50
• Unresponsive to non-operative, conservative treatment (rest, heat, electrotherapy, physical therapy, chiropractic care and/or analgesics) for:

• at least six weeks from radiculopathy or myeloradiculopathy symptom onset; or
• have the presence of progressive symptoms or signs of nerve root/spinal cord compression despite continued non-operative conservative treatment.
• Reported to be medically cleared for surgery
• Physically and mentally able and willing to comply with the Protocol, including the ability to read and complete required forms and willing and able to adhere to the scheduled follow-up visits and requirements of the Protocol;
• Written informed consent provided by subject.

Exclusion criteria

• Has, in the Investigator's opinion, any disease or condition that would preclude accurate radiographic evaluation of any treated vertebrae (e.g. morbid obesity)
• Active systemic infection or infection at the operative site
• History of or anticipated treatment for active systemic infection, including HIV or Hepatitis C
• Previous trauma to the C3 to C7 levels resulting in significant bony or disco-ligamentous cervical spine injury that may prevent device placement
• A prior spine surgery or pseudoarthrosis at the operative levels
• Axial neck pain in the absence of other symptoms of radiculopathy or myeloradiculopathy justifying the need for surgical intervention
• Symptomatic DDD or significant cervical spondylosis at more than two levels
• Diagnosis of Spondylolisthesis, grade >2
• Overt (Segmental) instability measured as a movement on dynamic flex/extend x-rays > 3.5 mm
• Congenital bony and/or spinal cord abnormalities that affect spinal stability
• Diagnosis of Paget's disease, osteomalacia, or any other metabolic bone disease other than osteopenia
• Osteoporosis, defined as either the SCORE or MORES ≥ 6 and a DEXA bone density measured T-score of ≤ -2.5
• Active malignancy or a history of any invasive malignancy (except non-melanoma skin cancer), unless treated with curative intent and without clinical signs or symptoms of the malignancy for at least five years
• Has an uncontrolled seizure disorder
• Use of epidural steroids within 14 days prior to surgery
• A concomitant condition requiring daily, high-dose oral and/or inhaled steroids. High dose steroid use is defined as:

• daily, chronic use of oral steroids of 5 mg/day or greater.
• use of short-term (less than 10 days) oral steroids at a daily dose greater than 40 mg within one month of the study procedure.
• Known allergy to titanium (Ti)
• Fixed or permanent neurologic deficit related to the target treatment levels that cannot be improved with surgical decompression
• Has, in the Investigator's opinion, any disease or condition that would preclude accurate clinical evaluation (e.g. neuromuscular disorders)
• Is pregnant or nursing at time of screening, or with plans to become pregnant throughout the duration of the study.
• A current or recent history (≤ 1 year prior to screening) of substance abuse (alcoholism and/or narcotic addiction) that required treatment
• Long term use (>6 months) of opioids (max. daily amount=120 mg morphine equivalents)
• A mental illness or belongs to a vulnerable population, as determined by the Investigator (e.g., prisoner or developmentally disabled), that would compromise ability to provide informed consent or compliance with follow-up requirements
• Any other condition or anatomy (e.g. fused facet) that makes posterior fusion treatment infeasible
• Use of any other investigational drug or medical device within the last 30 days prior to surgery
• Pending personal litigation relating to spinal injury (worker's compensation is not exclusionary)
• Anticipated or potential relocation greater than 50 miles that may interfere with completion of follow-up examinations.