I am surprised that osteoarthritis arthritis is causing your hand to be numb. Arthritis in the neck making your hand numb is usually a reason for surgery, if that is the case, since it means a pinched nerve, which can result in permanent loss of nerve function.
Carpal tunnel syndrome can cause numbness, however. And is often treated with splints and PT, tho' surgery is simple and will relieve it, too.
For my hand arthritis pain (fingers are distorted, tips are bent at angles, joints are knobby and painful) I find that
Cymbalta (on label for arthritis pain),
Aleve (miraculous for me but I had to stop after years of use, due to gastric distress even with Omeprazole)
a low dose of Medrol (methyprednisolone)
and Gabapentin (trade name Neurontin) all help tremendously.
My Left knee and my right shoulder are deteriorating. I may have my knee replaced down the line, but not the shoulder. My big toes are 'fused' with arthritis. I have had three surgeries on my left hand, one due to arthritis. One due to carpal tunnel, and one due to a trigger finger (finger 'jams' because the ligament has a bump and doesn't release when the finger is bent).
And I have constant pain from the Degenerative Disk Disease in my neck which is osteoarthritis. I also have osteoarthritis in my lumbar spine. Most people do when they are 65 or older. I recently had a fairly simple surgery on my lumbar spine, but I am avoiding surgery on my neck and fusions in my lumbar spine. At 74 I'm hope to 'go out' without more serious spine surgery.
Osteoarthritis is the disease that affects the most people in the world, and there is no way to cure or treat it at the present time. All we can do is alleviate the pain and replace the joints that are worn out, usually hips and knees.
Best wishes with your hands, Cricket. We want to do the things we enjoy as long as we can.