I am sorry about your joint pain in your finger, I know it is painful and distracts from playing our sweet strings.
I have Rhematoid Arthritis and so I don't play for too long, I am happy when I get to practice my MD for a hour. Hand splints have helped me play, but I always use a noter because my finger joints won't handle the pressure of chording.
My noter I slip into my hand splint (a bambo chopstick) or when I am not using a hand splint I use a hard wood spoon for a noter. This allows my hand to loosely hold the spoon with the palm of my hand and takes tension off the small joints in my fingers.
I think what has helped me is shorten my playing times or rest in between, but also I use foods or supplements in my diet to help joint health and inflammation.
I eat lots of dark berries; raspberries, blueberries, blackberries, also fresh ginger, tumeric.
Some suppliments that help me are flaxseed oil, glucosamine and fishoil.
I wish you well in finding your way with this painful distraction and continue to enjoy playing your sweet strings.