I had a fusion on L4/5 back in 1997. it did not go smooth at all, I am doing ok now. I am about to have another fusion in my neck at the end of the month.
The Dr. said he uses a type of stem cell to grow bone in a plastic cage like device. I hope it works out. Good luck out there everyone with back problems, we need it.

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1976 240D
1976 240D parts car
1970 220D daily driver