What is post fusion syndrome?

[bigdonkey1]

I have had 4 back surgeries in 8 yrs. the last was a 2 level fusion L3-L5. I suffered miserably for 6 months, finally i started to be fully pain free to the point i did a small triathlon 9 months after surgery. i have been pain free for almost 2 yrs, working around the house, biking skiing etc. now for some unknown reason i have recurrent pain in my back and leg numbness and pain in my foot and leg again. same side as before. the MRI is negative for new damage, the xrays appear clear from damage. The DR is extremly helpful and understanding, yet seems mystified as to what is causing this pain now. "oh it should go away" i have had 2 cortisone shots and it is still painful and extremely uncomfortable.
I wonder is this normal and i was living a cinderella life up to now? if there is no new damage, and the fusion is intact and normal, what could be irritating the nerves?
If surgery is an option, what would he fix? and if there is nothing wrong, then WHY AM I IN SO MUCH PAIN?

[toolmaker]

I agree it sure sounds like scar tissue.

[clinicalmanager]

Your pain may be due to the formation of new scare tissue s/p your last surgery. Scare issue can cause inflammation which can mimic your previous sciatic pain.