Hi @weten2
I had PMR which became GCA for a year before diagnosis; also knee surgery for severed ligaments when I was in my late 20s. Both are painful conditions. The knee pain localized, the PMR body-wide from the neck down for me at least.
Did your physician diagnose your PMR? Have you spoken to her/him about your upcoming surgery and the impact it could have on your symptoms?
Are you currently taking prednisone?
Surgery can cause an inflammatory response in the body, but prednisone controls inflammation.
Maybe your doctor can consult with the surgeon and a rheumatologist as well and they can figure out the best course of action for you.
Good luck.