PCM Cervical Disc System

The PCM Cervical Disc was studied in a prospective, multicenter, randomized FDA-approved investigational device exemption (IDE) clinical trial conducted in the United States to evaluate longitudinal outcomes over 2 years comparatively between the PCM Cervical Disc and anterior cervical discectomy and fusion (ACDF) with allograft and plate. Patients with adjacent or non-adjacent prior fusion were allowed. A total of 416 patients with a degenerated cervical disc at one level from C3-C4 to C7-T1 were enrolled in the clinical trial and 403 were treated. Patients were randomly assigned to be treated either with the PCM Cervical Disc or ACDF.

Patients were evaluated before surgery, during the operation, immediately after surgery, and then at 6 weeks, 3 months, 6 months, 12 months and 24 months, and yearly after surgery. The patients were recommended to have a physical therapy program for non-impact exercises and active range of motion exercises after surgery. Patients were also instructed to avoid repetitive cervical flexion and extension bending and lateral bending and rotation for 6 weeks following surgery.

The safety of the PCM Cervical Disc was assessed by comparing the adverse events, any additional surgical procedures, and the neurological outcomes to those in the ACDF control group. The effectiveness of the PCM Cervical Disc was assessed by evaluating patients' pain and function outcomes using a standard questionnaire, the Neck Disability Index (NDI), the severity of neck and arm pain based on a Visual Analog Scale (VAS) assessment, quality of life using a standard questionnaire, the Short Form-36 (SF-36), as well as a patient satisfaction questionnaire compared to the ACDF control group. In addition, the patients were evaluated using radiographic evaluations, including spinal range of motion, spinal disc height, device displacement or migration, spinal fusion status, and heterotopic ossification (abnormal bone formation).

The primary endpoint of the IDE trial was a composite measure termed "overall success," which was evaluated at 24 months postoperatively, and was defined as at least 20% improvement in neck disability index (NDI) from preoperative score; absence of reoperation, revision, or removal; maintenance or improvement in neurological status; and absence of radiographic or major complications during the 24-month follow-up period.

On October 26, 2012, the FDA granted Premarket Approval (PMA) for the PCM Cervical Disc. PCM Cervical Disc is indicated for use in skeletally mature patients for reconstruction of a degenerated cervical disc at one level from C3-C4 to C6-C7 following single-level discectomy for intractable radiculopathy (arm pain and/or a neurological deficit), with or without neck pain, or myelopathy due to a single-level abnormality localized to the disc space, and manifested by at least one of the following conditions confirmed by radiographic imaging (CT, MRI, X-rays): herniated nucleus pulposus, spondylosis (defined by the presence of osteophytes), and/or visible loss of disc height as compared to adjacent levels.

Inclusion criteria

• Age 18-65 years;
• Diagnosis of radiculopathy or myelopathy of the cervical spine between C3-4 and C7-T1;
• Symptomatic at only one level from C3-C4 to C7-T1;
• Unresponsive to non-operative treatment for six weeks, or has the presence of progressive symptoms or signs of nerve root/spinal cord compression in the face of conservative treatment;
• Baseline NDI score of ≥30/100;
• Radiographically determined pathology at level to be treated correlating to primary symptoms, including at least one of the following: decreased disc height, degenerative spondylosis on CT or MRI, or disc herniation;
• Appropriate for treatment using an anterior surgical approach, including having no more than one previous anterior surgical approach to the cervical spine;
• Ability and willingness to comply with follow-up regimen; and
• Written informed consent given by subject or subject's legally authorized representative.

Exclusion criteria

• Infection at the site of surgery;
• History of, or anticipated treatment for, active systemic infection, including HIV infection or hepatitis C;
• Prior attempted or completed cervical spine surgery, except (1) laminoforaminotomy with less than one-third facetectomy at any level, or (2) a successful single-level anterior cervical fusion;
• More than one immobile vertebral level between C1-T1 from any cause, including but not limited to congenital abnormalities, osteoarthritic "spontaneous" fusions, and prior cervical spinal fusions;
• Previous trauma to the C3-T1 levels resulting in significant bony or disco-ligamentous cervical spine injury;
• Axial neck pain in the absence of other symptoms of radiculopathy or myelopathy justifying the need for surgical intervention;
• Radiographic confirmation of severe facet joint disease or degeneration.
• Osteoporosis:
• Severe diabetes mellitus requiring daily insulin management;
• Active malignancy: a history of any invasive malignancy (except non-melanoma skin cancer), unless the patient has been treated with curative intent and there have been no clinical signs or symptoms of the malignancy for at least 5 years;
• Tumor as source of symptoms;
• Symptomatic DDD or significant cervical spondylosis at two or more levels;
• Known or suspected allergy to cobalt, chromium, molybdenum, titanium, or polyethylene;
• Severe myelopathy to the extent that the patient is wheelchair bound;
• Pregnant (verified in patients of childbearing potential by a negative urine pregnancy test when preadmission testing is obtained), or interested in becoming pregnant during the duration of the study;
• Autoimmune disorders that impact the musculoskeletal system (e.g., lupus, rheumatoid arthritis; ankylosing spondylitis);
• Spinal axis disease (thoracic or lumbar) to the extent that surgical consideration is likely anticipated within 6 months after the cervical randomized procedure;
• Other degenerative joint disease (e.g. shoulder, hip, knee) to the extent that surgical consideration is likely anticipated within 6 months after the cervical randomized procedure;
• Previous spine surgery within the 6 months preceding the cervical randomized procedure;
• Current or recent history of substance abuse (drug or alcohol);
• Morbid obesity, defined as body mass index ("BMI") > 40 or more than 100 lbs. over ideal body weight;
• Currently using, or planning to use, bone growth stimulators in the cervical spine;
• Use of any other investigational drug or medical device within the last 30 days prior to surgery
• Currently a prisoner; or
• Currently pursuing personal litigation related to the neck or cervical spine injury; however, involvement in worker's compensation related litigation is not a required exclusion.