A case of rheumatoid arthritis with unilateral knee synovial hypertrophy in hemiplegia

A 64-year-old woman suffering right hemiplegia came in with pain and swelling on her left knee, general weakness and poor oral intake for 2 months. On physical examination we were able to palpate a mass with irregular margin around the left suprapatellar area. From the results of the magnetic resonance imaging (MRI), synovial proliferative disease, infectious arthritis, or gouty arthritis was suspected. We performed a blood laboratory test to detect rheumatologic diseases, knee joint aspiration, and bone scan for differential diagnosis, and were able to diagnose rheumatoid arthritis (RA) from the results of blood laboratory, physical examination, and bone scan. Consequently, we started medications for controlling RA. Herein, we report a case of rheumatoid arthritis with unilateral knee synovial hypertrophy in hemiplegia. If a right hemiplegic patient has recurrent pain on the left knee and synovial hypertrophy, and fails to respond to treatment for osteoarthritis, early detection by evaluation for rheumatic disease is crucial to prevent severe sequelae influencing rehabilitation of hemiplegia.