"Is there some reason you have not had yours replaced?"

The only thing that I can't do that I really want to do is run - I was a serious runner for 25 years but my knees are too sore to run now.

I can still ride as much as I wish, both mountain and street, and walking long distances is still OK.

SO - I figure the longer I wait to have my knees replaced the better will be the techniques and materials. My orthopedic surgeon and his predecessor have been taking care of my knees since 1980 and they both keep telling me that nothing I do now can make them any worse. I can not do any more damage than age, time, and abuse has already done.

They agree that the longer I wait the better will be the results.

And... my best friend, running, riding, skiing, climbing buddy since 1966 had a knee replacement three years ago. He has had two followup surgeries to clear adhesions (scar tissue) but he still has very limited range of motion and that is where it will stay. He is TOUGH and was overly conscientious in his recovery. He did everything and more they asked and still got bad results. He is also an advanced Yoga master and is the most flexible old guy I know. That bad result scares me.

On the other hand - my dad had both knees done and was still hiking and biking with me when he was 85 so that is an encouraging result.

As long as I can walk and ride, and sail my boat, I'll wait.