I'm guessing there are screws and cables to remove which can be irritating some nerves. Have you asked about that?
All of the "instrumentation" looks fine - nothing loose. Another problem is I'am very lean in build - not much meat on my bones for fusion to take place.
I am not an expert but that just dont sound right.I thought all hardware was permanent.If it were me I would consult another surgeon before I went through this again.