I'm sure there are plenty of other GN's with hip and knee replacements but it does strike me that society needs to re-think our image.
I'm 64, work for myself, and still enjoy various sports in spite of having had both hips replaced and my right knee two years ago. I don't think this is too unusual as that's what they were made for ie: to keep us active. Other people's reactions generally, though, make me wonder if I should be out without a carer. We need far more awareness of how this amazing technology is allowing so many of us to continue "normal" lives and be useful and busy.
On the downside, of course, the high price of metal means that I now scurry past scrapyards - just in case they spot me as worth weighing in!