Do you mean that you had fusion surgery 5 months ago and now they're saying it neeRAB to be redone? 5 months is way too soon to decide that you're not fused. Fusion can take a full year, sometimes even longer. Did something else go wrong? Did a level above or below the current fusion go bad?
I'm sorry you're looking at more surgery already. Like Lena said, ask lots of questions!
I wish you the best,
Emily