Cervical Advice Required
 

I had ADFS at C5/6 in 2012 with cadaver bone and hardware. Last August the hardware was removed due to swallowing issues. This all knowing my fusion did not fully fuse with new bone growth. My X-rays 3 months after the removal shows compression of my spinal cord again. Why would that occur and what would cause this after the 1st decompression? This was the reason for my ADFS.
My surgeon is going to do a revision surgery posteriorly with decompression with hardware again. I asked if he could use my hip bone instead of a cadaver. He said no need, he is only doing a decompression. Why wouldn't he redo the failed fusion while doing the decompression? How will leaving this affect me? Will the bone actually fuse after 10 years of not? He says that it is securely in place but is it really? He also said it may look like it's starting to fuse, is why I am asking. There is absolutely no white line of new bone growth and rather dark.