Im 8 yrs post knee replacement. If you intend to ride during post op rehabilitation, teaching yourself and your animal to mount on the off side makes sense.

Very important in my view, is to properly rehab your knee. This is important to regain and maintain strength, as well as maintaining your full range of motion. Proper rehab will get you back in the saddle quicker and safer. Rehab is painful and progress will start slow and get better as it goes along. You wont regret it later. Im painfree, have my full range of motion, and feel better than I have in years. Good luck!

Regards,
Manny