Effect on Pain and Symptoms of Aspiration Before Hyaluronan Injection for Knee Osteoarthritis

Abstract

The main objective of this study was to observe whether synovial fluid aspiration of the knee joint compared to no aspiration, before and after 5 weekly injections of intra-articular hyaluronan, provides an improvement in knee pain and physical function. Patients were randomized to an arthrocentesis group (n = 92) or a nonarthrocentesis group (n = 88). In the arthrocentesis group, knee joints were maximally aspirated before each hyaluronan administration. In the nonarthrocentesis group, synovial fluid was not removed. Hyaluronan was injected into the knee joints once a week for 5 weeks. Patients were followed up for 25 weeks. Outcome measures included patient pain (using the 100-mm visual analog scale [VAS] during a 50-foot walking test), Western Ontario McMaster University Osteoarthritis Index (WOMAC) function scores, and overall effectiveness evaluated by patients and investigators on a scale of 1 to 6. The arthrocentesis group showed significantly greater improvement from baseline to week 25 in VAS pain (P < 0.001) and WOMAC function scores (P < 0.001) than the nonarthrocentesis group. However, the differences of patient and investigator assessment of effectiveness did not achieve significance. Synovial fluid drainage before injection of intra-articular hyaluronan significantly improved VAS pain and WOMAC function scores in patients with knee osteoarthritis, however, the differences of patient and investigator assessment did not achieve significance.