Clinical and biochemical characteristics after intra-articular injection for the treatment of osteoarthritis of the knee: prospective randomized study of sodium hyaluronate and corticosteroid.

BACKGROUND: Intra-articular injections of sodium hyaluronate (Na-HA) and corticosteroid (CS) are often used for the treatment of osteoarthritis (OA), and the clinical usefulness of such treatment has been reported. Some studies have discussed the effectiveness of intra-articular drug injection therapy in terms of the clinical results, but no cohort studies have performed evaluations of effectiveness based on changes in joint biomarkers. This prospective randomized study compared the efficacy of Na-HA and CS injections based on clinical scores and levels of biochemical markers for osteoarthritis.

METHODS: A total of 51 patients with knee osteoarthritis received intra-articular injections of either Na-HA or CS and were followed for 6 months after treatment. Pain and inflammatory scores were evaluated at the baseline, at 5 weeks, and at 6 months. We also measured joint fluid levels of hyaluronan (HA), chondroitin 6-sulfate, chondroitin 4-sulfate, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP (TIMP)-1 at the baseline and at 5 weeks.

RESULTS: In both groups, injection therapy significantly improved pain/inflammation scores and visual analog scale scores with time (P < 0.01). HA levels were significantly increased after injection only in the Na-HA group (P < 0.05); and the MMP-9 level decreased significantly after injection only in the Na-HA group (P < 0.01). Other marker levels did not differ significantly between groups.

CONCLUSIONS: The results of this prospective randomized study suggest that the clinical effects of Na-HA and CS as local therapies for OA are comparable and that both drugs are useful. Considering the results of the measurement of biomarkers, compared with CS injection therapy Na-HA injection therapy may have protective effects on the articular cartilage by increasing the HA concentration in synovial fluid, as well as inhibitory effects on the catabolism of articular cartilage by reducing the MMP-9 concentration.