When I broke my tibea plateau, my orthopedic surgeon told me what needed to be done, and explained that if I didnt have the surgery, I'd have a 97% chance of getting osteoarthrosis in the joint and going through a knee replacement later. And that if I did get the surgery, I'd have only about a 3% chance of needing a knee replacement.
Titanium plate, six screws, bone graft... 9 years ago. I get a little pain sometimes but nothing I cant handle. I'm sure its nothing compared to what you're going through.
I have a friend that had his knee replaced, he was awake for the surgery and walking (with a walker) the very next day. And now he gets around just fine, and he is old enough that the artificial joint will probably last longer than he will.
And you're correct about the cortizone shots. The last one in my ankle only lasted for three weeks. They used to last 2x that long.