Originally Posted by
BlazingPedals
Plenty of folks in my bike club have bionic knees. So far, I've never heard of one falling and breaking the replacement. If the possibility really bothers you, get a trike.
When I asked my surgeon about the risks from a crash he commented that it was unlikely to damage the prothesis in a crash, but more often what happens is a broken femur because there is no flex in a prothesis. Last summer I crashed and landed on the left side of my head, and my left --- not to distantly replaced --- knee. I embedded a rock right on the incision scar, but no broken anything.