I don't know who is right but I can tell you that I had two herniations and surgery to remove them twice. I then had a fusion and bone was put in the spaces and my fusion was solid when I had a follow up MRI a year later. I still have the symptoms I had before the surgery but everything is healed and in place. Not having your bone or cadaver bone put in sounds strange to me. I would go for a second opinion if I were you. It's been a very long time not to have a solid fusion yet.
I know it's been a long time. I say I got 20% better after the laminectomy. The CT scan now looks like a stalactite and stalagmite trying to join in the middle, and it's just as thin and pointy also. I need to be immobile for awhile until it spans the gap. Which one doctor said it could take one or two years, 20 years to fully fuse. That is outrageous to me! If they did the right procedure for hyper degenerative disc disease it would take 7 months to a year.
So, you didn't get any better? A CT scan shows bone better. When looking at my MRI the doctor told me it was fused you just can't see it with an MRI, you need a CT scan to see it, but trust me, it's fully fused, he said. It happens that I did have a series of CT scans with me, and I said "show me where it's fused because new bone shows up bright white? He didn't answer. I said look it's just the back of the vertebral bodies that's trying to bridge the gap, closest to the instrumentation. It kind of looks like an hour glass that's broken and jagged in the middle.
My MRI showed fully fused a yr later plain as day. I would seek another opinion because this doesn't sound right to you or me. I hope others comment on their experiences for you as well. I'm fully fused but it didnt get rid of my pain so it's considered a failed procedure. I also used a bone growth stimulator for 4 hrs a day for several months following the surgery and I was in a brace. I hope you can get this sorted out and on your road to recovering. If you have any questions feel free to message me. I will try and help.