Hey MB, I have to second your opinion and also add that that is mostly because of my own experience.  I had very serious congenital hip problems that began manifesting in earnest when I was a mere pup (35.)  From that time until I was 47 things got so bad that I could barely get my socks on by myself.  Needless to say there was no canoeing or tripping, something I had done and loved from the time I was 9 years old.  The added shame of it was that my wife had also been very much into canoeing and backcountry tripping and in our first 20 years together we never even talked about it much less shared the experience.  When I was 55 I had my second hip replaced.  Three months later my wife and I were out hiking in Algonquin Park and realized we could paddled together.  We spent the next 4 years regaining our chops by renting a small ranger cabin in Algonquin, getting our equipment together and going on a few 4 and 5 day trips from the cabin.  The rest, as they say, is history.  We'll be heading out August 1st for our 7th, month long jaunt in the remote Ontario Northwest.  I feel younger, fitter and happier now at 66 than ever I did when I was 40.  Degrading joints not only affect and limit us physically, they also have a huge emotional impact.  Speaking for myself, I was becoming increasingly irritable and bitter without even realizing it.  I have not been a big fan of Western medicine but when it comes to joint replacement surgery it can perform miracles.  I am told that one of these years, maybe sooner or later, I will have to have my aortal valve replaced (again, a congenital malformation.)  Forty years ago that would have been a 50-50 proposition.  Now ... well it's still open heart surgery but the success rate is phenomenal.  I feel blessed to live at a time when this is true.  My advice to anyone over 50 - go get your hips replaced. Whether you need it or not, you'll feel like a million bucks ... just kidding!!