spine-care-innovations

Spine Care Innovations: Artificial Disc Replacement

By Thomas E. Menke, M.D.

The unquestionable success of hip and knee replacement surgery has understandably triggered an effort to find a similar procedure for the spine. Several different types of disc replacement prostheses have been implanted in Europe for over ten years. The potential benefits of such surgery—preservation of spinal motion and minimization of adjacent level stress—are also unquestionable. In the spine, however, there are a few more major obstacles to overcome.

Because the vertebra of the spine are much smaller bones than the femur, tibia, and pelvis, there is less space and fewer options available to obtain a bone-prosthesis interface. Also, the vertebra articulate with one another, not only through the disc, but also through two facet joints at each level. Replacing only the disc leaves the native facet joints as possible sources of pain and/or future degeneration. Additionally, we are attempting to couple artificial surface motion with native joint surface motion which may actually increase facet joint pain and degeneration. Finally, even when short-term success can be achieved, prosthesis wear is a major concern. Prosthesis wear has been a significant problem for the intermediate and long-term success of hip and knee replacement, even though this surgery is generally performed on the elderly. Disc replacement candidates are young, active patients in whom prosthesis wear is almost certain to be a major problem.

Successful artificial disc replacement is a lofty goal worthy of further investigation. Current techniques and biomaterials have not shown the ability to achieve long-term success. Therefore, we must temper our enthusiasm for this evolving treatment option.

Last Updated: 10/4/03