RESUMO
BACKGROUND:Intra-articular injection of sodium hyaluronate is an effective method for the treatment of knee osteoarthritis, with significant effect and less adverse reactions, but the mechanism is unclear. OBJECTIVE:Through testing the malondialdehyde and superoxide dismutase levels in the synovial fluid of knee osteoarthritis before and after injection of sodium hyaluronate, to evaluate the clinical efficacy of sodium hyaluronate in the treatment of knee osteoarthritis. METHODS:Thirty-seven patients with knee osteoarthritis (40 knees) were enroled and divided into mild (n=10, 10 knees), moderate (n=17, 18 knees), and severe (n=10, 12 knees) groups according to the Japan's knee osteoarthritis indications. Patients were subjected to intra-articular injection of 25 mg sodium hyaluronate, once a week for 5 weeks. The levels of malondialdehyde and superoxide dismutase in the synovial fluid before and 4 weeks after treatment were detected, and then clinical effects were evaluated based on the clinical scores according to the Japan’s knee osteoarthritis indications. RESULTS AND CONCLUSION: The indication rating results of the mild and moderate groups were decreased significantly 4 weeks after injection (P < 0.05), but there were no significant difference in the severe group before and after treatment. The malondialdehyde level in the synovial fluid was decreased obviously in the three groups at 4 weeks after injection (P < 0.05), while the level of superoxide dismutase was increased remarkably (P < 0.05). These findings indicate that sodium hyaluronate can treat knee osteoarthritis by reducing the malondialdehyde level and increasing superoxide dismutase level in the synovial fluid, but this method is more suitable for treatment of mild to moderate knee osteoarthritis.