There are nerve stimulators that can be implanted which might be worth learning about. I, too, am fused from L2 to L5. Now I have significant pain from L5-S1 and from both S-I joints. Those are the only remaining areas that can move in my lower back. Find a neurosurgeon you trust and ask about a spinal nerve stimulator. I think it would be worth asking about. Good luck and I'm sorry you are in so much pain.