@quickray Welcome to Connect. At the time I was headed toward spine surgery, The M6 artificial disc was in clinical trials and it was described as having more natural movement than other artificial disks. One question that comes to my mind would be why a calcified disk is an issue. They should explain what they mean by not fusing right. Artificial disks are screwed into the bone, and don't fuse to the bone. Bone quality is very important. Also if there is any instability or side, forward or backward movement of one vertebrae over another, it may disqualify a patient for ADR. During the clinical trials, 4mm of movement was a dis-qualifier. I had 2mm of movement, and my surgeon would have done ADR if I had wanted that, but said I was not a great candidate for it with that much movement.

I had a C5/C6 single level fusion and did that without any hardware. I had just a bone disc spacer and stayed in a brace until fused. My body doesn't like foreign materials, and I had so many problems wearing pierced earrings that I had to give them up, so that was a good choice for me.

I did not loose much movement in my neck because C1 & C2 do most of the head turning with a little bit of help from C3 & C4. Maybe 1% would be from C5, but my range of motion is normal and the same as before my surgery for head turning. What I can't do is touch my chin to my chest, but it is very close, and spine bending tricks like somersaults or back bends are out of the question. Normal functioning and walking around, driving etc is fine.

Running or any sport pounding your spine is going to put wear and tear into the equation. Once you have spine surgery, it isn't automatic that you will have more problems at adjacent levels, but extra wear and tear is not going to help, and bad posture will add extra stress. If you have good posture and stack the vertebrae ergonomically, you have a better chance to lessen the wear over time. You may want to switch to exercise that is gentle like an elliptical jogging machine or simple walking.

Artificial disks can fail, screws can pull out, and the body can grow bone around an artificial disk trying to stabilize it. There is medical literature that describes all of that. Adjacent segment disease can happen both with artificial disks or fusions, probably to a slightly lesser degree with artificial disks, and if your body reacts to foreign materials like mine, that wouldn't be good. I found out how much I reacted to titanium by breaking my ankle and having plates attached to my bones. Because I had only one spinal level fused, I was able to opt for no hardware. I agree with you that fusing 2 levels seems a bit much and it could possibly be for the extra insurance money that would be earned by the surgeon and not as much for your benefit. Many surgeons are conservative and would not do another level unless it was really bad. You might need some more opinions from surgeons on this. Get as many as you need.

There is also a lab in Chicago that tests for immune responses to surgical implants. However, an allergic or immune response can develop after a period of time after the hardware is in your body, so a test that says you don't react isn't always a predictor of future issues, but it could catch a response if you have it now, and then you could consider a fusion with only a bone spacer like I did. I encourage you to keep asking questions of the surgeons and reading medical literature. The lab is https://www.orthopedicanalysis.com/

Are you considering getting another surgical opinion?