Can you tell the difference between rheumatoid and osteo arthritis from an x-ray?

Usually . These two forms of arthritis often damage the bone in different ways.
Sometimes. Rheumatoid arthritis and osteoarthritis have different findings on x-rays. However, x-rays can be normal. Also it is possible to have both osteoarthritis and rheumatoid arthritis. Therefore, while x-rays are helpful, they cannot completely exclude one disease or the other by themselves and are used in combination with a history, exam and review of risk factors.