Cervical Artificial Disc Preserves Neck Mobility
An Interview with Richard Guyer, MD
SpineUniverse: Dr. Guyer, to begin our interview, when is a cervical artificial disc used and for what types of spinal conditions or disorders?
Dr. Guyer: A cervical artificial disc may be used in a patient who undergoes spine surgery to relieve pressure on nerves in the spine. Spine specialists refer to this condition as nerve root compression. Some patients with cervical nerve root compression present with symptoms that include neck and arm pain. Most patients find that their symptoms are resolved with non-operative treatments. However, in a small percentage of cases, some patients do not respond well to non-operative care and therefore spine surgery is either an option or becomes necessary.
SpineUniverse: What causes nerve root compression and what is the goal of surgical treatment?
Dr. Guyer: Nerve root compression can be caused by a disc herniation, degenerative loss of disc height, or from bone spurs. Any of these conditions can narrow or obstruct nerve pathways. Traditional surgery alleviates nerve compression by removing the diseased disc, restoring lost disc space between the upper and lower vertebrae, and fusing the vertebrae together. Although the procedure helps to alleviate the patient's symptoms, after the neck heals and fuses, the motion in the vertebral segment is lost. The beauty of an artificial disc is it is designed to preserve motion at the vertebral segment and may lessen stress to adjacent spinal levels.
SpineUniverse: Is there a particular type of surgical procedure used to relieve nerve root compression?
Dr. Guyer: In general, the surgical procedure performed is called an anterior cervical discectomy and fusion. This means the surgical incision or approach, is made at the front of the neck (anterior) and the diseased or damaged disc is removed (discectomy). The empty disc space is filled with the patient's own bone (called autograft) or other graft product to induce new bone to grow between the vertebrae. A cervical plate and screws are implanted to provide immediate spinal stability. Over time, the bone graft does its job to cement, or permanently fuse that particular spinal segment into one piece. Basically, the same procedure is used to implant a cervical artificial disc, except the need for fusion is eliminated.
SpineUniverse: What are the advantages to cervical disc replacement versus traditional instrumentation and fusion?
Dr. Guyer: One immediate advantage to using an artificial disc is that one does not have to wait for fusion to occur. Post-operative recovery is shortened and patients may or may not be placed in a soft collar. Patients can return to near normal activities -- except of course, vigorous athletic activities until the wound has satisfactorily healed and the artificial disc is firmly attached to bone.
Also - the need for internal fixation such as a cervical plate and screws is eliminated and only the intervertebral space is violated. If a plate and screws are used in a fusion procedure, there is the possibility that the levels above and below the fusion will be affected.
The added advantage to an artificial disc is that is maintains motion and lessens the chance of transition syndrome, which can be a real problem in traditional spinal fusion. Transition syndrome means a segment of the spine adjacent to the fused segment degenerates or breaks down, which can affect disc height and spinal stability.
Since bone grafts are not needed, the patient is spared a surgical procedure where their own bone is harvested from their hip (iliac crest), which can be painful post-operatively.
SpineUniverse: Could an artificial disc be considered similar to joint replacement?
Dr. Guyer: Yes. An artificial disc is designed to restore and maintain motion at a particular spinal level. Historically, if we go back thirty or forty years ago and examine how diseased hips and knees were surgically treated, we find that the joints were fused, which eliminated joint motion. Today, total hip and knee joint replacement is common. I'm optimistic that artificial discs will lead spine care in a similar direction.
SpineUniverse: Is there a specific cervical artificial disc you are working with now?
Dr. Guyer: Yes. It is the PRODISC-CÂ® Total Cervical Disc Replacement.
To learn about Dr. Guyer’s practice, click here.