Talk to Orthopedic Surgeon on Internal Knee Pain

I am a 27 yeard old femal, unmarried. I started experiencing pain in my left knee almost 4 years ago which is continued till now. last year I had MRI which showed joint effusion of some type and my doc prescribed me Arthrodar and carti5 for 3 months. I took it but now the pain has started again since 3 weeks. I met some senior doc too but he said ignore MRI report, had some tests too, they were normal. and he told me nothing... Please any orthopedic doc can you guide me what should I do for my knee pain now? I cant waste any more money. Please guide me in best possible way.