With chronic low back pain, I am at a cross-roads decision point: should I have a lumbar fusion or a disc replacement? The surgeon has explained both and all the plusses and minuses of each. My biggest concern is for the long-term results. What will my back be like 10 or 20 years from now?
A very reasonable question when suffering chronic pain and facing spinal surgery. And one that doesn't have a straight forward "this" or "that" answer. But it appears you already know this from your comment that your surgeon has reviewed with you all the pros and cons of each treatment option.
One of the reasons there isn't a definitive answer to your question is the fact that disc replacements have not bee studied (in this country) for 20 or more years. Early studies comparing fusion to disc replacement haven't really shown a huge benefit of one technique over another.
That's a bit surprising but the one stumbling block that keeps coming up is something called adjacent segment disease (ASD). ASD refers to the fact that once the spine is fused, load is transferred to the next segment potentially causing degeneration there as well.
The word potentially is used because researchers aren't sure that it's the loss of motion and transfer of load that creates the problem. There are many surgeons who suspect the same amount of degenerative disc disease would develop as a natural consequence of aging. This point has not been proven yet, so until the argument is put to rest, there is no clear winner of disc replacement over spinal fusion or vice versa.
Each patient must make this decision along with his or her surgeon. Your lifestyle (active versus inactive), general health, and personal goals combined with what the surgeon tells you about each procedure will guide your final choice.