Artificial disc replacement

Artificial disc replacement is a medical procedure in which degenerated discs in the spine are replaced with artificial ones. The procedure is also known as "total disc arthroplasty." It is primarily used to treat chronic, severe low back pain from degenerative disc disease.

Presently the standard of care for chronic pain from a degenerated disc is spinal fusion surgery. This involves fusing two or more vertebrae together to remove motion in those segments of the spine, thus reducing or eliminating pain associated with the motion. The artificial disc has been developed with the goal of reducing or eliminating the pain while still allowing motion in those segments of the spine, thus retaining the original physiologic makeup of the spine. Another theoretical advantage of the artificial disc is that it should prevent premature breakdown of adjacent levels of the low spine, which is currently a potential risk of spine fusion surgery.

Artificial disc surgery is relatively new in the U.S. but has been used in many countries (mainly in Europe) for over 10 years. In the U.S., only two brands of artificial disc have been approved for use in the general patient population: the Charite artificial disc, which is manufactured by DePuy Acromed, and the ProDisc, manufactured by Synthes. Both of these discs have completed clinical trials and have received FDA approval for use in the lumbar spine at one-level, either L4/L5 or L5/S1. A new innovative disc called the Prestige cervical disc has been tested and in a U.S. clinical trial, patients showed "improved neurological success at 24 months and improved overall success". Two-level disc replacement surgery is still considered experimental in the U.S. but, again, has been used in other countries (mainly Europe) for many years.

While two discs have been F.D.A. approved for one-level replacement, some insurance companies in the U.S. still deny this surgery outright for all patients, considering the surgery "experimental." Interestingly, data shows that artificial disc replacement patients, as compared to spinal fusion patients, have shorter surgeries, less blood loss, shorter hospital stays and that they return to work sooner following surgery.

The ProDisc was invented by a French orthopedic surgeon, Thierry Marnay, in the late 1980s.

The first surgeon to perform a ProDisc artificial disc surgery in the United States was Jack Zigler, a spine surgeon at the Texas Back Institute in Plano, Texas, on October 3, 2001. The ProDisc is also in clinical trials for the cervical spine and should receive FDA approval soon. A number of other anterior artificial discs are currently in various phases of development and testing including the FlexiCore, Kineflex and Maverick discs.

In addition to total disc replacement, some companies are also working on developing products and methodologies to replace just the inner portion of the disc, called disc nucleus replacement. These new techniques would allow for posterior insertion and a potentially shorter surgery with fewer complications.