Maybe Spine Universe.

The bit I know about Sacrum fusion is it is not common area to fuse. and can cause more problems. I also have problem diwn there. So have some experience from my very cautious and excellent Spine neuro surgeon and my pain doctor. I had successfully RFA, solved problem. Also be careful w stretching, would think it helps but not. I had to stop allot of exercise/ stretch so pain stayed at bay
Did you try RFA. Look up a post I made about Radio Frequency ablation. I only discussed on my Cspine but also had done on my Lumbar and Sacrum. Also for Sacrum they can to a cold version tht is suppose to be excellent, but it is not covered by many insurance companies. Look at my previous post, done last 2 weeks- tht noone responded. But you will see my response/ help to others. Always make sure u get another opinion from a suegeon not affiliated w the practice . There are many who have no clue what they are doing or do unnecessary surgery. Same goes for procedure s