yes something like 60, but if you need it like your mate it must be done.
I was told at the time (55) that a knee replacement lasts about 15 yrs. and that they really only like to do one operation and not do the same knee a second time. Of course by that time technology will be further advanced to where my Doc's info won't be applicable, maybe even now.
long story short between my knee, my ungodly shift work sched. and severe sleep apnea I gained a lot of weight and acquired heal pain, and my knee hurt tremendously. I went from a guy who played just about every sport to layed up basically. Horrible. Now with the sleep thing and work sorted out and cortisone injections, I've lost about 65 pounds and the pains are reduced big time. Even easing back into playing golf.
Now I'm thinking if I get down to where I should be I may not need one for a long while.