John McLaughlin has an interesting way of dealing with arthritis. From an interview in the Irish Times-

“I’m still into my yoga and my meditation, because that’s an integral part of my life, and before my meditation, I sit down and go into my hands and I talk to them, and I tell them how beautiful they are, how much I love them, and how marvellous and miraculous they are. Now, since the last three years, I have no pain at all. I’ve never felt better musically. We are capable of amazing things, but we underestimate ourselves.”

I'm doing this, I figure it can't hurt but I've been dealing with it in both hands for about 15 years now and I've managed it somewhat with a lot of stretching and strengthening exercises that I got from a therapist after a thumb arthroplasty and by easing the action on my instruments with lighter strings and going with instruments with shorter scales and capoing up the neck more with different chord voicings. Another thing I've done is shifting the position of the guitar, I've found that angling the neck up a bit and moving the instrument slightly to the right makes barre chords a little easier, basically just going with what's comfortable.