Hi.
You have got a rare symptom of recurring
knee effusion that is not responding to repeated aspiration, MRI of knees being normal, going on for last 3 months.
The most probable cause I can think about is a specific infection like
tuberculosis or so that can cause such recurring knee effusion.
Hence I would advise you the following:
Consult your Orthopedic Surgeon to discuss about the possible causes, get the blood tests for Tuberculosis.
Aspiration of knee fluid and send for detailed chemical analysis, to find Tuberculosis or other diseases that cause recurrent effusion.
Arthroscopy and biopsy of the
Synovial membrane ives best diagnosis and chance for proper management as per the cause found.
Oral or topical
steroids may helps if there is no specific cause that can be found.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon