I had discs fused in 1991 and another op. In 1995, everything was fine i was riding the Peak without any bother until last September. Over Christmas i was in agony, never had pain like it, turns out i had some fragments from my previous op’s pushing on a nerve.
Had an injection to block the nerve late January and i’m just getting back to normal now, riding again etc. With just a slight numbness in my right foot.
It does get better just takes time and patience. Good luck with it, the boredom is worse than the pain sometimes!