Artificial disc surgery is still relatively new in the United States, but in Europe, the procedure has been used for more than 15 years. Artificial total disc replacement was developed as an alternative to spinal fusion, the goal being to reduce or eliminate pain, while still allowing for motion throughout the spine.

Ever since surgeons began working with TDR to treat pain and other neurological symptoms for patients suffering from degenerative discs, there has been skepticism. New studies show they are faring better than as once thought. Let's look at the differences.

Spinal fusion, also called anterior cervical discectomy and fusion, is a surgical technique used to join two or more vertebrae. These are the bone and tissue structures that house and protect your spinal cord in the spinal canal. Spinal discs are pads that act as cushions between the bones, or vertebrae, of the spinal column. When these discs become damaged or herniated, pain and reduced mobility may result. In fusion surgery, bone tissue from the patient or a donor, is used in conjunction with the body's natural bone growth processes to fuse the vertebrae.

A spinal fusion surgery is designed to prevent motion at a painful vertebral segment, which in turn should decrease pain generated from the joint. But, all of the joints in the spine work as a team. When the entire spine is healthy, each segment works to share the load on the spinal column. So, when one or two segments are not working properly, the neighboring segments have to take on more of the load. Segments closest to the non-working segments get most of the extra stress. Over time, this can lead to increased wear and tear on this segment, eventually causing pain from the damaged segment. This is called a transitional syndrome because it occurs where the transition from a normal area of the spine to the abnormal area that has been fused.

Because of the time needed for fused joints to heal, recovery can be as long as three months, during which time physical activity must be limited.

TDR, also known as total disc arthroplasty or spinal arthroplasty, is a surgical procedure designed to reduce pain as well as associated radiating limb pain due to degenerative disc disease and injury. The difference is that it replaces the entire degenerated disc, with hopes of maintaining mobility.

Although there is no definitive evidence that TDR reduces the incidence of transitional syndrome, several clinical trials have shown cervical TDR to be equivalent if not superior to fusion. The ability of TDR to allow decompression while maintaining motion has led many to suggest that transitional syndrome, as well as reoperation rates may be decreased when compared to fusion surgery. Some studies reported better neurologic outcomes with TDR versus fusion.

Also, the artificial discs still on the market now are beginning to show a very positive track record.

From my experience, the upsides are small incisions, diminished post-operative pain, a faster return to work and reduced need for postoperative bracing.

Because bone healing is not required following an artificial disk implantation, the typical patient is encouraged to move. Early motion may translate into quicker rehabilitation and recovery.

This said, artificial discs are mechanical devices that can fail and do not last forever.

As with any surgery, there is a risk of complications. When surgery is performed around the spine and spinal cord, these complications can be serious and could involve subsequent pain and the need for additional surgery. You should discuss the complication risks associated with any procedure with your doctor before surgery.

Dr. Jeffery T. MacMillan is an orthopedic surgeon at St. Mary's Joint and Spine Institute and can be reached at 816-655-5354.