Suggest Treatment For Pain/discomfort In Hip While Having Rheumatoid Arthritis

My mother is 55 years old, suffering from rheumatoid arthritis since 1990. she has already done two knee replacements & one hip replacement (right side) in 2001, England. she is taking methotrexate, oraxin from last 20 years. Now she is suffering from left sided hip with severe pain & discomfort. I am suspecting that her left hip has damaged. I want to know about the treatment, its cost and other facilities available in your country.