Wow, here I am 5 days post op from a R knee PFJR and, so far so good!! I'm 39 and was worried I'd be too young but I wasn't, and I've had it, and so far, I feel good!! I've written a full post op diary in the post op section of the boards. Hope you'll find it useful/interesting reading
Message me if it's something you're considering and (like me) you need to know more and be reassured.