Here is one reversal surgery I found. A Pro-disc was used on one or two cervical levels.....This lady had headache issues after neck fusion. This was done 7 years ago.

Of course, scoliosis makes things trickier, and we had pro-disc discussions here many years ago. Some have had single pro-discs installed under fusion masses in the lower lumbar....This doesn't seem to have taken off...

Now, using pro-discs with tethering is quite a concept. If they could control the tension of the tether using a device like Magec, that might be an idea worth some thought. Possibly multiple tethers?