@rainerhans , I’ve had both knees replaced, not at the same time, Knee surgery recovery is so painful, so I know what to you mean. I’ve also had my left hip replaced. Don’t be nervous, it’s actually not a bad surgery or recovery. When they got me up, I was bracing myself for the pain . I was surprised when there was I didn’t no pain at all with standing or walking! Only pain was from the incision, and it was very minimal. I didn’t even have PT, the surgeon said to walk.
Good luck on your surgery, if you made it through knee surgery, you’ll do great!