I’d say the majority of us on biologics take methotrexate alongside. Here’s an old post of mine: The Other Side of Planet Methotrexate.
Keep asking questions! The better you understand what’s happening, the better you will deal with it.
As for your knee, if you aren’t happy with the non-answers you are getting, it’s worth finding a new ortho. Your relationship with your rheumatologist and orthopaedic surgeon is probably going to be a long one, so you may as well find one who you are comfortable with.
If it takes a long time to get on the list of the one you really want, stay with the first until you’re on the second’s list. I’ve been seeing my orthopod since 2005, and my rheumatologist since 2014. I had to wait 2 years for the one I wanted. All worth it.