@bilton I was scheduled to have a TKR in February of 2014 due to having arthritis in my knee. At the very last minute, it was cancelled due to low platelets. From that point on I exercised a lot, a recumbent bike being a big part of my exercise. I was finally able to have the replacement done in October 2017. By that time my pain had decreased significantly and I was walking much better due to exercise that strengthened the supporting muscles. I had friends who thought I was crazy to go ahead with the TKR but I knew eventually it would get bad again so I did.

Other exercises I did were walking and pool jogging. It really was amazing how much the exercise helped. My orthopedic surgeon loves the recumbent bike, and water jogging for exercise, something I didn't even realize when I started doing them.

You really need to check with your doctor, I am not a medical person, just a patient who has been through that experience, but I suspect he will support you exercising. It's always possible that there is a reason for you to not do that and your doctor should know what is best for you.
JK