I had surgery preceded by a Stellate Ganglion Block via fluoroscopy and had no spread or flares, BUT it was very minor surgery with a meticulous surgeon who I know was very gentle and my treating RSD doc at the time. A knee replacement is going to be traumatic. Not only would a block presurgery be important, I'd suggest a series be preapproved for after in case of need. 6 would seem appropriate. And Ketamine should be considered as part of the anesthesia for the surgery.

Do you have access to warm water PT? If yes, do you tolerate it ok? If so, that would be something to consider asap after surgery.

Which knee is currently worse, btw? It's a tough decision for sure.