Good evening @vicki1234, Welcome to Connect, I have read your post and am a bit confused. I would like to be able to introduce you to others who have encountered a similar situation. We are going to need a bit more information from you. Here are some of my pondering thoughts.

When did you have the first surgery on your right knee? How long was it before the second surgery? You mention a build-up of scar tissue. Has that just happened?

What kind of physical therapy did you undergo after the first surgery? By chance, have you tried MFR, myofascial release therapy for scar tissue?

You indicate that your doctor may not even know about replacing plastic pads. Pardon my lack of understanding, but how could he/she not know if you are considering another surgery?

And finally, how would you like us to help you?

May you be free of suffering and the causes of suffering.
Chris