I agree with Bluetail. You'll be glad you did. I had mine done January 11, 2012 and was outside riding March 11, 2012. This year I'm on track to get to 5000 miles which is more than I've ever done. The right (replacement) knee still feels different than the left, but the difference is getting less all the time. Yesterday I spent 2-1/2 hours with the snow shovel. When I got done, I decided I should have used the blower, but it was because of my back, not the knee!

There was a thread here about wear and tear on an artificial knee. I'm not sure we reached a definitive conclusion but some interesting data were posted. Someone posted a plot from a power meter that showed that almost all the time, the force exerted on the pedal is far less than 1/2 the body weight. So that means just standing makes bigger forces than biking. Of course there's also the rubbing as the joint is flexed - that's a little harder to get a handle on. My take is that the flexing is comparable or a little larger than what happens on an elliptical. My doctor tells me I should get my exercise by swimming or with an elliptical. Neither is going to happen. But the interesting thing is the elliptical involves bigger forces and similar range of motion, so I have to believe the wear and tear from an elliptical is comparable to that from cycling.

Finally, even if cycling shortens the life of the knee, I'm sure my life would be a lot shorter without cycling. What's the point of having the knee last longer than you do?

- Ed