I have two TKR and one hip replacement, not yet mentioned is doing the PT as the key to success. I would ask the Therapist and or the surgeon if stair climbing,ie, your fiver steps canbe classified as PT. That is kind of a joke as I already know that most respond with "just be careful and have a ggood grasp on a hand rail.
I was asked the evening after the surgery if I had any pain and how severe. I told my surgeon that my only pain was from laying in bed and that I had not been allowed up. His response was wait until tomorrow morning and the you can resume normal activities, such as you can in a hospital.
So it all depends on your attitude, skill of your orthopedic surgeon and how badly you want to get out and about. I was only about 65 when I had the last knee done.