My experience with fusions is terrible ive had two L4/5 and L5S/1 neither of them gave me any pain relief and if anything made things worse , i think PT is the way to go but if after giving it your best effort for a few months your no better and if you must have an operation the cutting edge back surgery in the world is performed at The Bonati Institute or the Laser Institute in Florida.
I may be going there shortly.