I have not had a fusion, but have read on other forums as well as have a friend that had similar problems.
Once her hardware was removed her pain was gone.
She also said that the surgery to remove the hardware was far easier and quicker recovery than the fusion and surgery.
My own spine surgeon has told me that once your are fully fused, there is no reason for the hardware to be in place and he ends up having to remove hardware in 50% of his patients.
Just be sure that you are fully fused before the hardware removal surgery, unless you have not fused at all and need the fusion redone.
Fran