Osteoarthritis. Then how it can be made?

My mother is suffering from severe knee pain, consulted many doctors but could not find the exact reason for pain some say she has arthritis, some say synovial fluid is finished, some say that bones have become dry due to lack of synovial fluid, she had symptoms like pain in knee and below that and swelling in knee joint & ankle joint due to pain , she is not able to walk more than 10 minutes, she need to sit after every 10 minutes, seeing her symptoms i studied on net that she is suffering from bone marrow edema , osteoarthritis. Please tell me is it so? Am I right? If it is so please suggest me what is the treatment for this, if synovial fluid is less or no then how it can be made ? One thing more I want to tell we belong to middle class family we do not have much money to spend on , my parents have spend all money in making their children educated for which I m today able to write to you, so also please suggest me the best othropaedist where I can get my mother treated.