What Is An Artificial Disc?

The disc is the soft cushioning structure located between the individual bones of the spine, called “vertebra.” It is made of cartilage-like tissue and consists of an outer portion, called the annulus, and an inner portion, called the nucleus (Figure 1). In most cases, the disc is flexible enough to allow the spine to bend.

Who needs an artificial disc?

The indications for disc replacement may vary for each type of implant. Some general indications are pain arising from the disc that has not been adequately reduced with non-operative care such as medication, injections, chiropractic care and/or physical therapy. Typically, you will have had an MRI that shows disc degeneration. Often discography is performed to verify which disc(s), if any, is related to your pain. (Discography is a procedure in which dye is injected into the disc and X-rays and a CT scan are taken. See the NASS Patient Education brochure on Discography for more information.) The surgeon will correlate the results of these tests with findings from your history and physical examination to help determine the source of your pain.

There are several conditions that may preventyou from receiving a disc replacement.These include spondylolisthesis (the slipping of one vertebralbody across a lower one), osteoporosis, vertebral bodyfracture, allergy to the materials in the device, spinal tumor, spinal infection, morbid obesity, significant changes of the facet joints(joints in the back portion of the spine), pregnancy, chronic steroid use or autoimmune problems. Also, total disc replacements aredesigned to be implanted from an anterior approach (through the abdomen).You may be excluded from receiving and artificial disc if you previously had abdominal surgery or if the condition of the blood vessels in front of your spine increases the risk of significant injury during this type of spinal surgery.

Back pain is sometimes produced by an injured or degenerated disc. To treat this condition, alternatives to disc replacement include fusion, nonoperative care or no treatment. Typically, surgery is not considered for disc-related pain unless the pain has been severe for a prolonged period (typically over six months) and the patient has gone through nonoperative treatments (such as active physical therapy, medication, injections, activity modification and/or spinal manipulation).

How a Disc Is Replaced ?

Spine surgeons at the Cedars-Sinai Spine Center are at the forefront of development and evaluation of a safe and effective artificial disc. The evolution for hip and knee replacement has taken more than 40 years to reach its current stage of technology in materials, design and technique. Although the idea of an artificial disc is not new, artificial disc replacement technology has just in the recent decade become mature enough to be used clinically in extensive testing in Europe. The unique biomechanical challenges of artificial disc replacement have presented a challenge of both design and material.

Although revolutionary in material and design, the technique to install an artificial disc (whether in the neck or low back) is routine and safe. In both traditional disc surgery and artificial disc replacement the procedure begins by removing the gelatinous disc between the vertebrae.

Surgery: The Steps

• You will be given general anesthesia
• The surgery is performed through the abdomen, to allow a clearer and better access to the degenerated disc.
• Your surgeon will dissect a window in the annulus (spine anatomy->the disc) (outer part of the disc)
• The degenerate disc is carefully removed, enabling the insertion of the new disc.
• After a carefully confirmation of the size and height of the degenerated disc, the new artificial disc is inserted.
• The surgeon will then verify that the position of the new disc is correct using X-Ray.