good morning yummy!....yes!...Jane is correct in that I too have lots of pain at my fusion level. Also the MRI shows that it looks perfect as well...but still in severe pain. At the moment I'm waiting on a phone call from my dr to see if he will approve me seeing a local PM, who believes I should try Methadone. I originally went in to see if I was a candidate for the pump. However the PM is not one to jump to the pump, without trying all meds first.
I cannot answer your question about the hardware and the muscle..and agree with Jane that maybe your surgeon can share that information with you.
I feel for anyone who suffers from back pain and has had surgery to correct the problem. It is true that in some cases and maybe more, that your pain can actually become worse after the fusion. The surgery itself can involve cutting through many nerves and leave permanent damage. If that is the case, then a good nerve med may be required like Gabapentin and or Cymbalta to help with that.
I believe it takes a combination of meds to see any real relief for many who suffer such damage...and you would be wise to seek a good PM for your care.
Again, I'm terribly sorry you are having so much pain...I know full well what you may be going through.
Keep us updated on any answers you find, and any progress in treatment that helps you.
SE