While PT may not be needed, nobody here says that you should do no exercise at all. The exercise you do should be gentle, and should not cause pain. It can be incorporated into your activities of daily living. Walking is the best exercise of all for your knee. Start with short walks and build them up slowly.
Go to PT if you wish and if you like it, but remember that your knee is newly wounded. Don't allow it to be hurt or forced. It needs to heal before you work it hard. Doing too much, too soon, can make your healing soft tissues inflamed and swollen, which could slow down your progress. Find a balance, one that lets you feel you are making progress, but keeps your knee happy.
My surgeon does not allow formal PT for the first month after a TKR. He says that your knee needs that time, to begin its healing journey. That doesn't mean that his patients lie around like logs for a month. We get up to the bathroom and kitchen, make ourselves hot drinks and small snacks, walk around the house and progress to walking around the garden. At 4 weeks post-op, I undertook a 6-hour car journey, although not as a driver. I negotiated stairs and steps at my cousin's house. When I remembered, I was doing gentle
Heel slides and how to do them properly and my ROM was increasing gradually - it was well over 90 degrees by 6 weeks.
I've followed a similar recovery with both my TKRs. My legs are strong and reliable. They straighten fully and bend to over 125 degrees.
I'm getting old, but I'm not a rocking chair granny. With my new knees, I have travelled around the world. I walk through all the airports. In Viet Nam, I have swum at Ha-Long Bay and crawled through the viet cong tunnels at Cu Chi. I've snorkelled in Tahiti and over Australia's Great Barrier Reef.
I've never aspired to be an athlete, but l live a pretty active life.