Originally Posted by FrenchFit

So, my wife did both knees at 64, got in the stationary bike as quickly as possible, went for her normal bike as soon as the Dr. allowed. What he Dr.s are worried about with outdoor bike is emergency stops putting the foot down and flexing the knee backward. That is particularly dangerous for someone in TKR recovery. I think, and this is not a scientific opinion, that clipless are a potential problem if you ride them exclusively. You want lots of float while you are healing. My wife has always used pinned pedals, so not problem. I have noticed that her leg motion seems more under-pronated, or knees-out, after the surgery..but she's not complaining.

But I switch off from clipless to platforms cause I think riding clipless all the time isn't particularly good for old knees and ankles. Since I am more of a running enthusiast than cyclist I will always switch off between clipless and different platforms, I do not want to subject my knees and lower legs to an overly restrictive motion for hours. Just my 2 cents.