I don't know of a racking aide, but in lieu of that, you could always leave it open. It has a slide stop when the gun is empty, I presume?
Racking shouldn't be very difficult at all unless you are cocking the hammer at the same time. Of course, with the quality of today's ammo, you'll be doing that a lot.
Sorry I couldn't be of more help. I'm starting to get arthritis, too, so I may be looking for something like this soon, too.