Cervical Disc Degeneration

What is Cervical Disc Degeneration?

Degeneration of the cervical disc occurs as we age. Injury, daily wear and tear, and genetics also contribute to this process. Degeneration consists of damage to the cervical disc, which may then become narrowed or may herniate. This causes symptoms of pain, numbness, tingling, and/or weakness in the arms or shoulders, and may also cause neck pain. The available treatments are directed at these symptoms and do not represent a cure for the degenerative process.

Symptoms

Neck pain
Pain, numbness, or tingling in the arms or shoulders
Weakness in the arms or shoulders

Treating Cervical Disc Degeneration

The following provides an overview of standard, non-surgical and surgical treatments for cervical disc degeneration.

Non-operative Treatment

If cervical disc degeneration is established as a diagnosis, your doctor will likely recommend one or more of the following treatments:

Rest
Heat
Electrotherapy
Physical therapy
Injections
Bracing
Pain management modalities
Pain medicine

Your doctor can discuss recommended treatment options based on your individual needs.

Surgical Treatment

Cervical spine surgery for pain and other symptoms of cervical disc degeneration or herniation begins by making an incision in the neck, once anesthesia has been administered. During surgery, the surgeon will access the cervical spine from the front of your neck, and will remove the damaged disc and any tissue that is compressing the spinal cord and/or nerves. After removing the disc, the surgeon will implant a device to help stabilize the joint. Anterior cervical discectomy and fusion (ACDF) and cervical disc replacement procedures are comparable in their surgical approach and length of surgery time.

Anterior Cervical Discectomy and Fusion (ACDF) Surgery

ACDF is the current standard of care for cervical disc disease. Fusion surgery consists of removing the damaged disc. After the disc is removed, bone graft (bone taken from another area) or a synthetic spacer is placed into the disc space and a cervical plate with screws is used for stabilization. The goal of this procedure is to permanently fuse two or more vertebrae together so they do not move except as a single unit. This procedure may alleviate the pain and other symptoms of cervical disc disease. While an ACDF usually relieves pain and other symptoms, it does result in loss of motion in the fused joints.

Cervical Disc Replacement Surgery

An alternative procedure to an ACDF is a cervical disc replacement surgery, which aims to stabilize the spine allowing motion to occur at the joint instead of fusing the vertebrae together. For that reason, artificial cervical disc replacement devices such as the NuVasive® PCM® Cervical Disc have been developed.

Product Information

The PCM® Cervical Disc is designed to replace the diseased disc, providing support for the vertebrae while allowing for movement of the joint. The PCM Cervical Disc consists of the following parts: an upper metal (cobalt chromium molybdenum alloy) endplate, and a lower metal endplate to which a plastic (polyethylene) spacer is attached. These materials are the same as the ones used for most spinal and orthopedic devices. Several device sizes are available to best fit the disc space.

Is the PCM Cervical Disc Right For Me?

The 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. The PCM Cervical Disc is implanted using an anterior approach. Patients should have failed at least 6 weeks of conservative treatment prior to implantation of the PCM Cervical Disc.

PCM Cervical Disc Contraindications

The PCM Cervical Disc should not be implanted in patients with the following conditions:

Acute or chronic infections, local or systemic;
Osteoporosis, (defined as DEXA bone density measured T-Score ≤ -2.5) or osteopenia, (defined as DEXA bone density measured T-Score ≤ -1.0);
Congenital stenosis;
Allergy or sensitivity to any of the implant materials (cobalt, chromium, molybdenum, titanium, or polyethylene).

Warnings and Precautions

The clinical study was limited to patients that met certain criteria, therefore the safety and effectiveness of the PCM® device has not been established in patients with the following conditions:

Intractable radiculopathy or myelopathy due to disease at more than one level or disease outside of the disc space;
Marked cervical instability as determined by your doctor;
Significant cervical anatomical deformity or clinically compromised vertebral bodies at the affected level due to current or past trauma or disease;
Those under the age of 21 or over the age of 65;
More than one immobile vertebral level;
Severe spondylosis as determined by your doctor;
Patients whose bones are still growing;
Previous spine surgery at the level to be treated;
Symptoms attributed to more than one vertebral level;
Neck pain alone;
Neck or arm pain of unknown origin;
Severe facet joint arthritis of the level of spine for which surgery is planned;
Paget’s disease, osteomalacia, or other metabolic bone disease;
Cancer;
Those taking medications known to potentially interfere with bone or soft tissue healing (e.g., steroids);
Diabetes mellitus;
Systemic disease including AIDS, HIV, and hepatitis;
Auto-immune disorders that impact the musculoskeletal system such as lupus, rheumatoid arthritis, or ankylosing spondylitis;
Neuromuscular disorders such as muscular dystrophy (progressive loss of muscle), spinal muscular atrophy (decreased muscle), amyotrophic lateral sclerosis (Lou Gehrig’s disease);
Morbid obesity;
Pregnancy;
Mental illness and substance abuse;
Prior fusion at an adjacent vertebral level. Similar to the experience in the ACDF control group, the use of the PCM Cervical Disc at a spinal level adjacent to a previous fusion may lead to clinical outcomes inferior to those observed for patients without a prior adjacent level fusion. For the PCM device, these include, but are not limited to, possible implant migration and a higher incidence of subsequent device removal.

Magnetic Resonance Imaging (MRI) Safety

The PCM Cervical Disc has not been evaluated for safety and compatibility in the MRI environment. The PCM Cervical Disc has not been tested for heating or migration in the MRI environment.

Risks

As with any surgery, there are some possible serious risks that can occur when receiving the PCM Cervical Disc. Potential risks associated with the use of the PCM Cervical Disc include: 1) those commonly associated with any surgery; 2) those specifically associated with cervical spinal surgery using an anterior approach; and 3) those associated with a spinal implant, as well as those pertaining to the PCM Cervical Disc. However, the causality of these adverse events is not exclusive to these categories. Some of the following effects were observed in the clinical study.

Risks associated with any surgical procedure are those such as: Abscess (localized collection of pus surrounded by inflamed tissue); cellulitis (a diffuse and especially subcutaneous inflammation of connective tissue); wound dehiscence (wound breaks open along surgical suture); wound necrosis (wound contains dead tissue); edema (abnormal excess accumulation of fluid in connective tissue); hematoma (a mass of usually clotted blood that forms in a tissue, organ, or body space as a result of a broken blood vessel); heart and vascular complications; hypertension (higher than normal blood pressure); thrombosis (formation or presence of blood clot within a blood vessel); ischemia (a deficient supply of blood to a body part due to obstruction of inflow of arterial blood); embolism (sudden obstruction of a blood vessel by abnormal particle (e.g., air bubble) circulating in the blood); thromboembolism (the blocking of a blood vessel by a particle that has broken away from a blood clot at its site of formation); hemorrhage (a copious discharge of blood from the blood vessels); thrombophlebitis (the inflammation of a vein with formation of a thrombus); adverse reactions to anesthesia; pulmonary complications (pertaining to the lung); organ, nerve or muscular damage; gastrointestinal compromise; seizure, convulsion, or changes to mental status; and complications of pregnancy including miscarriage and fetal birth defects.
Risks associated with anterior interbody surgery of the cervical spine include: Dysphagia (difficulty swallowing); dysphonia (defective use of the voice); hoarseness; vocal cord paralysis; laryngeal palsy (an uncontrollable tremor or quivering of the larynx, which is the upper part of the respiratory passage); sore throat; recurring aspirations; nerve deficits or damage; tracheal, esophageal and pharyngeal perforation; airway obstruction; external chylorrhea (flow or discharge of chyle (fluid consisting of lymph and emulsified fat); warmth or tingling in the extremities; deficit or damage to the spinal cord, nerve roots, or nerves possibly resulting in paralysis or pain; dural (membrane that envelops spinal cord) tears or leaking; cerebrospinal fistula (an abnormal passage that leads from the spinal canal to another area of the body allowing for cerebrospinal fluid to leak out); discitis (an infection in the intervertebral disc space), arachnoiditis (an inflammation of the arachnoid membrane, a thin membrane of the brain and spinal cord), and/or other types of inflammation; loss of disc height; loss of proper curvature, correction, height or reduction of the spine; vertebral slipping; scarring, herniation or degeneration of adjacent discs; surrounding soft tissue damage, spinal stenosis (a narrowing or constriction of the spinal canal causing myelopathic (spinal) or radicular (nerve) symptoms); spondylolysis (the disintegration or dissolution of a vertebra); otitis media (an acute or chronic inflammation of the middle ear); fistula (abnormal connection between an artery and a vein); vascular damage and/or rupture; and headache.
Risks associated with implants in the spine, including the PCM Cervical Disc device: Early or late loosening of the components; disassembly; bending or breakage of any or all of the components; implant migration; malpositioning of the implant; loss of purchase (implant is no longer secured properly to bone); sizing issues with components; anatomical or technical difficulties; implant fracture; bone fracture; skin penetration; irritation, pain, bursitis resulting from pressure on the skin from component parts in patients with inadequate tissue coverage; foreign body reaction to the implants including possible tumor formation, autoimmune disease, metallosis (an infectious and often inflammatory disease of bone that occurs around metal implants as a result of corrosion or hypersensitivity reaction), and/or scarring; possible tissue reaction; bone resorption (loss of bone); bone formation (heterotopic ossification) that may reduce spinal motion or result in a fusion, either at the treated level or at adjacent levels; development of new radiculopathy (any pathological condition of the nerve roots); myelopathy (a disease or disorder of the spinal cord) or pain; tissue or nerve damage caused by improper positioning and placement of implants or instruments; loss of neurological function; decreased strength of extremities; decreased reflexes; appearance of cord or nerve root injury; loss of bowel and/or bladder control; and interference with radiographic imaging because of the presence of the implant.
Wound, local and/or systemic infections
Surgical instrument bending or breakage, as well as the possibility of a fragment of a broken instrument remaining in the patient
Inability to resume activities of normal daily living
Death

It is also possible that the surgery will not reduce or relieve your symptoms, and that treatment may not result in therapeutic or direct health benefits or may cause worsening of preoperative symptoms. Promptly notify your surgeon if the preoperative symptoms fail to improve or worsen, or new symptoms develop. This cannot be predicted for either the PCM implant or fusion surgery. If the implant does not relieve symptoms or if there is a problem with the device, it is usually possible to have it removed. This would require another surgery.

Potential Adverse Effects

In the U.S. clinical study of 214 patients who received the PCM® Cervical Disc, the most commonly or clinically significant reported device or surgery related adverse events included neck and arm pain 9.8% (21 patients), dysphagia/dysphonia 6.5% (14 patients), incision site complications 5.6% (12 patients), neurologic 5.6% (12 patients), spinal events 5.6% (12 patients), and implant loosening or dislodgement 4.7% (10 patients). In addition, 6.1% (13 patients) required removal of the PCM device and 1.4% (3 patients) required reoperations. There may be other risks associated with using the PCM Cervical Disc. Of the 190 patients who underwent ACDF, the most commonly reported device or surgery related adverse events included neck/arm pain 17.4% (33 patients), adjacent level disease 14.2% (27 patients), dysphagia/dysphonia 12.1% (23 patients), spinal events 6.3% (12 patients), nonunion 5.8% (11 patients), and neurologic 5.3% (10 patients). Although many of the major risks are listed here and in the patient information brochure, more comprehensive safety information is provided in the physician’s package insert for the product. Please ask your doctor for more information and an explanation of these risks.

Benefits

If the PCM Cervical Disc procedure is a success, it may result in the relief of symptoms such as decreased neck/arm pain. In addition, the joint may retain some degree of motion. The PCM Cervical Disc may allow patients to preserve cervical motion at the level of surgery, including axial rotation (turning your neck), lateral bending (side-to-side bending), and flexion-extension (nodding up or down). This may allow you to return to many of your normal activities.

More Information

What to Expect Before Surgery

Your doctor will review your condition and explain all of your treatment options, including medications, physical therapy, and other surgeries such as removal of the diseased disc, fusion, etc. Your doctor may also speak with you about preparations that you should make at your home, arranging for assistance, and the risks and benefits of this procedure. Please ensure that you have read and that you understand this entire brochure.

What to Expect During Surgery

During the PCM® Cervical Disc surgery, you will be under general anesthesia. The surgeon will access your spine from the front of your neck, and will remove the damaged disc and any tissue or obstructions that are compressing the nerves or spinal cord. After shaping the edges of the vertebrae to ensure a proper fit, the PCM Cervical Disc is inserted. The surgery lasts approximately one-to-two hours and most patients leave the hospital the following day.

What to Expect After Surgery

Treatment with the PCM Cervical Disc is major surgery. As with any major surgery, you should expect some discomfort as well as a period of rehabilitation. Your doctor may prescribe medications to manage any pain or nausea you might experience. On average, you should expect to stay in the hospital for one or two days.

After You Go Home

You and your doctor should discuss your recovery plan while the healing process takes place. It is very important to follow your doctor’s instructions. Your doctor may give you the following instructions:

A hard or soft collar may be used if your doctor thinks it is necessary
Avoid prolonged or strenuous activity
Avoid heavy physical activity until your doctor gives you permission
You will be taught how to clean and care for your wound
Your doctor may refer you to a physical therapist who will teach you exercises to improve your strength and mobility while protecting your spine and also different ways to position your neck to avoid reinjuring your spine.

Contact Your Doctor Immediately If:

You have a fever
The wound starts leaking fluids
You have trouble swallowing or breathing
You have new or increased neck or arm pain, numbness, or weakness
You have nausea and/or vomiting

Limitations To Postoperative Activity

Your doctor will instruct you on how to limit postoperative activity to reduce the risk of adverse events. The use of a cervical collar may be prescribed, depending on the doctor’s assessment of your activity level and overall condition. Generally, at one day postoperatively, you may start physical therapy but, non-impact exercises are preferred. Generally, at 3 weeks postoperative, you may do Pilates or light weight training with a 40lb weight-lifting restriction. Generally, after the 6 week visit, you may be unrestricted with regard to weight training provided radiographs demonstrate good alignment. Repetitive cervical flexion and extension bending or the extremes of lateral bending and rotation should be avoided for 6 weeks postoperatively. Remember to consult with your doctor before performing any of these activities.

Frequently Asked Questions

Can I Shower After Surgery?

Depending on your surgical incision, you may have showering restrictions. Ask your doctor for appropriate instructions.

Will I Have a Scar?

The surgical incision is usually about one inch long and usually heals so that it is barely visible. Ask your doctor for more information as every patient is different.

When Can I Drive?

For a period of time after your surgery, you may be cautioned about activities such as driving. Your doctor will tell you when you may drive again.

Can I Travel?

The PCM Cervical Disc may interfere with metal detection devices depending on the sensitivity of the equipment. Because of increased airport security measures, please call your local airport authority before traveling to get information that might help you pass through security more quickly and easily. Ask your surgeon to provide a patient identification card.

If you have any questions about the PCM Cervical Disc or cervical spine surgery, please call or see your doctor, who is the only one qualified to diagnose and treat your spinal condition. This patient information is not a replacement for professional medical advice.

U.S. Clinical Study Information

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. 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).

In the study, the average patient age was 45-years-old and 52% of the patients were men. Before surgery, approximately 80% of patients had symptoms of radiculopathy (a pathologic condition of the nerve roots) and approximately 19% had both radiculopathy and myelopathy (a disease or disorder of the spinal cord) symptoms.

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. At the 24 months, overall success was achieved by 75.1% of the PCM patients compared to 64.9% of the ACDF patients.

In the U.S. clinical study of 214 patients who received the PCM Cervical Disc, the most commonly reported device or surgery related adverse events included neck and arm pain 2.3% (5 patients), incision site complications 5.6% (12 patients), dysphagia/dysphonia 5.1% (11 patients), and implant loosening or dislodgement 2.3% (5 patients). In addition, 6.0% (13 patients) required removal of the PCM device and 1.4% (3 patients) required reoperations. There may be other risks associated with using the PCM Cervical Disc. Of the 190 patients that were treated with ACDF, the most commonly reported device or surgery related adverse events included neck/arm pain 16.8% (32 patients), adjacent level disease 14.2% (27 patients), dysphagia/dysphonia 12.1% (23 patients), nonunion 5.8% (11 patients), and neurologic 5.3% (10 patients). Although many of the major risks are listed in this patient information webpage, more comprehensive safety information is provided in the physician’s package insert for the product. Please ask your doctor for more information and an explanation of these risks.

Complete information will be available in the PCM PMA Summary of Safety and Effectiveness Data (P100012) at www.fda.gov.

Other Clinical Resources

The growing body of evidence supports the fact that in well-selected patients, cervical arthroplasty is at least as successful (defined in several clinically meaningful ways) as the “gold standard” treatment of ACDF and may indeed offer advantages. Historic FDA-approved randomized, multicenter IDE clinical trials comparing cervical arthroplasty to ACDF were designed as non-inferiority clinical trials. These trials, conducted with the goal of FDA product approval, used more stringent success criteria than the historical ACDF studies and yet each individually showed at least non-inferiority of cervical arthroplasty compared with fusion. However, individually, the trials were not statistically powered to demonstrate a statistically significant improvement in clinical outcomes or “superiority” of one procedure over the other. A recently published paper using a meta-analysis was performed to pool the data from four approved cervical arthroplasty devices, including the PCM Cervical Disc, in an attempt to improve the statistical strength of the analysis.¹ The results of this meta-analysis suggest that for the common indications studied (1-level cervical disc degeneration with radiculopathy and/or myelopathy), cervical arthroplasty is not statistically different from ACDF in NDI success (15-point improvement from baseline) but is statistically superior to ACDF in the overall success (a composite risk-benefit endpoint), neurological success (maintenance of improvement neurological status from baseline) and survivorship (absence of revisions) outcomes 24 months postoperatively.

McAfee PC, Reah C, Gilder K, Eisermann L, Cunningham B. A Meta-Analysis of Comparative Outcomes Following Cervical Arthroplasty or Anterior Cervical Fusion: Results From 4 Prospective Multicenter Randomized Clinical Trials and Up to 1226 Patients. Spine;2012, 37:943-952.

Read the full, published meta-analysis paper in Spine by clicking below.

http://journals.lww.com/spinejournal/Abstract/2012/05150/A_Meta_Analysis_of_Comparative_Outcomes_Following.7.aspx