This post has been cross post to news:alt.support.arthritis ,,,, click on
that.   The correct way to answer all your questions would take quite a post
but I do think you should make a copy of your own post and hand it to your
RD.   I have had steroid shots in my knees, shoulders, feet, and back.
Sometimes they would put the fire out and some times I would I would need
another one in four months.  My RD would not give me more than 3 in one
joint in a year.  Steroids do their own kind of damage which is the reason
for that.   The last two I have gotten is for inflamed cartilage in my rib
cage.
    You do not say what you take for RA which might make the steroid shots
not needed.   Its your DMARD that makes the difference but with OA when a
joint get bad enough,,,,, it has to be replaced or fused.
Harv