There's like 100 different types of arthritis, though OA is the most prevalent as it is due to joints just wearing out.Good question. It’s not rheumatoid arthritis, so I guess it’s osteo.
Knee replacements and a new hip soon.
But I will definitely take your nightshade advice (except maybe, potatoes)
Thanks for your helpful info!
Good luck on your new, upgraded parts. I really hope they help.