Grandma with severe arthritis

Once the joints are fused and contorted, is there anything to do?
My grandma is in her late 90's and her arthritis has rapidly progressed the last year or two.
She eats a low fat, SAD diet, but has always been healthy. She is 99, active, alert and still lives indepently with her 96 year old sister.
Would deep tissue oil type of massage oil work anything with these gnarled fingers?
Or an oral herbal remedy help at all? Tweet