I've suffered with Osteo Arthritis in multiple joints for more than 10 years, but am still managing to gig. However I am not as fast as I was, and really struggle on faster numbers, some of which I now only play at half tempo. Happily my band do not insist on every line being played exactly as the original, provided the Key riffs are good - we do take some artistic licence!
I switched to 30" Short Scale basses (Fender SS Jazz and Mustang) and class D amps.
I find it important to keep warm although the first couple of songs always hurt my hands, it does help to do warm up finger exercises before going on. Sometimes my fingers are hurting really badly whilst playing, and I wonder if I will be able to continue, but if I play though it so far it has always eased as I continue, although my fingers do become a little numb. The following day I am always very stiff and sore, and find I have to relax the days before and the day after every gig.
It's not just the hands though - my shoulders and spine hurt too. I use a good wide strap, and try to move around on stage to keep mobile, though there isn't always room to do so!
We are a Function Band, and often have a lot of hanging around before and between sets. Occasionally I will take pain killers if I feel really sore, but usually the adrenalin will get me through
Both Keith Richards and Ronnie Wood have very arthritic hands but it doesn't stop them playing stadiums, and I take some comfort from their lead