We discovered early last year my wife had what they called advanced arthritis in one knee and now we have confirmed it in on other knee...
I am really sorry to hear about your wife - bone on bone at 44 is really tuff. Although the doctors don’t like to do a replacement that young here’s the problem..
When it gets bad your wife start avoid movement.. and movement as we know burns calories. I was so bad people would come over to my desk so I wouldn’t have to gimp over -> Snowball Weight Gain. Weight is the enemy of knees.
Having an ache all the time wears you down and that sunny disposition will have to fight hard to shine through. I’m no tuff guy I found myself constantly rubbing the affending knee.
I wouldnt go 20, 10 or even 5 years. I vividly remember that first knee. I had just gone through a round of injections and I could barely walk the hallway to my doctors offices... He said “I guess you are ready”. The waiting period was about a month...