Hi Ray, I had my right knee replacement done in my mid 70s and like you I don't want one done on the left knee even though it may have to happen some day in the future. I try to work on my leg muscles daily and because I can't walk very well I mostly exercise on a Teeter FreeStep Cross Trainer which is like an exercise bike but you also use your arms. At 82 I don't yet have any pain with the left knee but I know it's bone on bone so not much cartilage left in knee. Next year I'm going to try and figure out how to walk more outside other than doing laps with a shopping cart at the grocery store 🤣. Too cold now and winter is right around the corner. I've thought about using one of those stretchy knee braces that gives a little more strength to the knee but haven't got one yet.

One day at a time my friend!