Not sure which type of arthritis you're dealing with, but....
I discovered years ago (through avoidance diets) that eliminating nightshades from my diet vastly improved a tendency toward arthritis/stiffness in my hands and other joints.
Nightshades are: tomatoes, potatoes, peppers & eggplant.
Yes, it was very difficult at first...but I wanted to be able to use my hands. Sooooooo, I persevered. I've found over time that I can allow myself a few of them (occasionally) as "treats" if I don't overdo it...I mean, what's shrimp without cocktail sauce???
Maybe it would help you?