How much synovial fluid is there in the knee when you have rheumatoid arthritis?

In healthy individuals, the synovial fluid volume in the knee is typically around 2-3 milliliters. However, in individuals with rheumatoid arthritis (RA), the synovial fluid volume can increase significantly due to inflammation and swelling of the synovium, the membrane that lines the joint. In severe cases of RA, the synovial fluid volume in the knee can exceed 10 milliliters.