Hello, and welcome.
My name is ***** ***** it will be my pleasure to assist with your question.
You should let your airline know about your 2 artificial knees, but you don't have to do it in person, you can tell them on the phone. However, you can also contact TSA Cares and Passenger Support, if you need help getting through the TSA screening process, if you wish:
You can give them a call, now, as they are still open (see the phone and email information on the right of the page above?), but technically, you're supposed to call 72 hours before your flight.
If you don't need any aid to walk, that's great, but if you would like a wheelchair, when you enter the airport, you can let them know, and it should also get you through the screening lanes more quickly. Lines are long now, with the summer travel, especially, because this is a holiday weekend, so if you can't stand for a long period of time, requesting a wheelchair would be a good idea. If you don't need one, so much the better!
Call TSA Cares now, and explain your situation, so they can determine if you need their services.
I wish you a wonderful trip!
Please be so kind as to rate my answer with positive feedback, as that is the only way I receive recognition for my assistance. Thank you very much!
Providing a positive rating will not end our conversation, should you need me for any follow-up. Simply click 'Reply' for clarification or additional information, if needed.