The aim of this study was to find if a complete synovial fluid aspiration before injection of intra-articular high molecular weight hyaluronan influences the treatment result for knees with rheumatoid arthritis (RA), including joint effusion and the prognostic factors related to clinical effect.
The arthritic knees including effusion were randomized to arthrocentesis or no arthrocentesis before the hyaluronan (1.9-2.5 x 10(6)) was injected into knee joints five times every week. All patients were followed up for 6 months.
One hundred eighteen RA patients (80 knees in the arthrocentesis group, 81 knees in the no-arthrocentesis group) were included. The proportion of no relapses in the arthrocentesis group was higher than that in the no-arthrocentesis group. In the arthrocentesis group, regression analysis showed that duration of knee arthritis (<5 months), CRP (<4 mg/dl), and Larsen grade (<grade II) were the significant predictors.
Arthrocentesis is effective in reducing the risk for arthritis relapse by intra-articular hyaluronan injection to rheumatoid knees with joint effusion. Predicting responders are duration of knee arthritis, CRP, and radiological scores.