The theoretical advantage of lumbar disc replacement over spine fusion is that the replaced disc would allow motion at the damaged level and would not transfer stresses to adjacent levels. The goal is to achieve the same pain reduction as spinal fusion, but eliminate some of the complications.
Unfortunately, lumbar disc replacement is a new surgery. While it is tempting to accept that this is a "better" treatment (pain reduction with less complications), we do not know if that is really the case. Lumbar disc replacements can break and they can become infected. Furthermore, the metal and plastic can itself wear out causing problems down the road. The question is which treatment offers the best result with the lowest complication rate. The answer, right now, is that we do not know. Lumbar disc replacements have not been performed on enough patients for a long enough time to know what potential problems may arise from this surgery.
Where Are We Now?A recent review in the journal Orthopedics Today reported the findings of several European studies. These studies found good results in about 75-85% of patients. This is about the results expected with spinal fusion. Unfortunately, these studies only lasted about one year, and thus the long-term results are not well understood. More research needs to be done before lumbar disc replacement is a standard option for degenerative disc disease, but it could be a future treatment.