I have a spinal fusion at L34. I’ve heard there can be problems with increased motion and degeneration at the level above and below the fused site. Is there anything I can do to keep this from happening?

Right now surgeons are trying artificial disc replacements (ADRs) in patients like yourself. The goal is to limit how much force is put on segments adjacent to the fusion. This is especially important for patients with multisegmental level fusions (in other words, long fusions over several segments).

No one is sure yet just what will happen in the long run with this type of surgery. The ADR may restore or preserve motion at that level, but what happens then at the next level? Can adjacent level degeneration following fusion be stopped with a single-level ADR? Does it take a two-level ADR to have the best results?

Bioengineers at the University of Toledo Spine Research Center are using computer-simulated models to study this problem. Most recently, they compared two different models and measured the results in terms of motion, load, and stress on the spine. The first model had a two-level ADR. The second model was a L5-S1 fusion using a cage and pedicle screw system along with an ADR at the L45 level.

The results varied and the researchers were unable to say one method worked better than the other. They each had their advantages and disadvantages. The bottom-line answer to your question is: more study is needed before anyone will know!