I have had three family members who got knew replacements. Not sure any of them were a "success."
One family member did not do the PT and wobbled and hobbled for the rest of their life. I don't know if this is true or not, but we were told that knee replacement leads to an increase chance of strokes. That makes sense to me for some period of time after the procedure but years afterwards? This family member had so many strokes we lost count. Have no idea if the strokes were connected to the replacement or not, but I would ask the surgeon if I was having the replacement. This was also decades ago and I have been told the procedures are much better now.
Another had to do the replacement due to pain, got the best doctor they could find, waited for surgery, and the result is so so. The physical therapist may have done some damage in PT. The person did do the PT as directed best I can tell. The pain has gotten better but the person still has pain and trouble walking.
The third person I don't know if they did the PT as directed, has injured the knee after the replacement, and still has issues walking as well as pain.
As others have said, research the doctor and hospital and use one that does many of these surgeries with high success.
From reading about this topic on TBN over the years, it seems like the replacement works for some, but not for others. Roll the dice it seems to be.
Flip side is, once the pain is so bad, one really does not have a choice but to roll the dice and see if the surgery helps.
Later,
Dan