Tough to comment on without seeing the fingers in question. If there is concern about the specific joints themselves, a plain film of the fingers can be performed as well as an evaluation by an orthopedic physician or hand specialist.
Rheumatoid arthritis is a systemic disorder and likely will affect all of the joints in general, rather than specific ones. If this is a concern, you can be tested for it with blood tests (an ANA test, rheumatoid factor and sedimentation rate can all be considered).
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b