Intra-articular injection of high molecular weight hyaluronan after arthrocentesis as treatment for rheumatoid knees with joint effusion

Objective: 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. Methods: 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. Results: 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. Conclusions: 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.