I have some arthritis in my right thumb, and a bit in my left, and "snapping fingers (sometimes described as "trigger fingers", though not quite the same.)
I study with Alison Cheroff, who teaches Taubman technique. If I play with my thumb correctly, as taught, there is no pain in my thumbs or fingers. I also had the action on my piano rebuilt so it is lighter, but not feather-weight.
I highly recommend the Taubman approach for any playing, but especially for hand injuries and arthritis.
On another note, I took a lot of Tylenol and an Nsaids, with no relief, and a stomachache. Diclofenac cream also caused stomach pain. I really didn't want to destroy my liver. I like Imak compression gloves and I'll use a soft brace on my thumb if I am not playing piano. https://www.amazon.com/IMAK-Active-...g=v2HsA&pd_rd_i=B007JVIG1S&psc=1https://www.ohmyarthritis.com/Shop-Splints/Thumb-Splints/3pp-Design-Line-Thumb-Splint.html
I have used hot wax "bath" , but it's a bit of a nuisance. Not sure if it helps. Some people really love it.
I tried splints- they really got in the way, and my teacher felt they inhibited motion detrimentally.
I have heard that some people have had success with surgery, but I hope to never go that route. I an 76, and have only been playing piano for 4 years. Just love it and feel it actually helps my arthritis. https://thepainfreepianist.com/aboutalisoncheroff.htmlhttps://www.golandskyinstitute.org/resources/
Hope that helps!