I had TKR in 2004 and 2005 the only major pain I had was doing the exercises for the first 2 weeks and then a week or 2 of very tolerable pain. I have not had one problem with discomfort in all these years. They are close to failing and the wait time for TKR is over a year so being 80 with this disease doesn't seem possible.
I read all the comments and oh so many horror stories. I can't in my wildest of thoughts see why the surgeon wouldn't be immediately concerned. Maybe consult someone else if possible. I still can do stairs. My heart goes out to you, nerf. All the best. TRUTH