though i've yet to have a knee replacement(but at 60, it's in my future), i have had 7 knee surgeries. one was a ACL reconstruction.
but i know many that have had replacements and the key for them and for me, was hitting the rehab hard.
most that return to a very active life, were very dedicated to pushing the rehab exercises hard and being able to push past the pain.
the ones i know that still have issues, were the type to stop if things started hurting and weren't dedicated to their rehab.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC