I didn't have that exact surgery but I did have a 4-level discectomy and fusion 11 months ago.

I don't believe there's an exact answer to your question. Even though I know you'd like one! Bone growth is slow and I was told to expect 9-12 months before I felt "like myself". For me - it was less than nine months (maybe six?) and today I have zero pain and discomfort. Certainly I lost some range of motion due to the fusion but that was expected and normal.

I also came to appreciate there was nothing I could do to shorten the bone-growth time table. I tried but to no avail.

I am very happy I had the 4-level surgery which was done at the best facility with the best neurosurgeon. Good luck!