Study on the effect of sodium hyaluronate intra-articular injection on the treatment of knee osteoarthritis

OBJECTIVE: To investigate the effect of sodium hyaluronate (SH) intra-articular injection on the treatment of knee osteoarthritis (OA), and to compare the contents of free radicals and inflammatory factors in joint fluids of pre- and pro-treatment as to explore the treatment mechanism of SH. METHODS: Ninety-two patients (111 knees) with mild(51), moderate (35) and serious (25) knee OA were treated with intra-articular injections of SH (20 mg once a week for 5 weeks). According to Lysholm scoring, clinical signs such as pain, swelling,and the ability to walk, squat, run, go upstairs and downstairs were assessed before and after the treatment, and the contents of nitric oxide (NO), superoxide dismutase(SOD), malonic dialdehyde (MDA) and IL-1beta, TNF-alpha in joint fluids from the OA joints before 1st, 2nd, and 5th injection and 3 months after each injection were observed. RESULTS: All cases were followed up for 3 months. The improvements in the signs and function of knees were excellent in 42 knees, good in 38 knees, fair in 21 knees and poor in 10 knees, with 72.1% excellent and good results. The lighter the illness was, the better the improvement was: the rate of the excellent and good was 92.1% in mild group, 68.6% in moderate group and 42.9% in serious group. The contents of oxygen free radicals and IL-1beta, TNF-alpha of the patients with mild and moderate OA decreased markedly after being treated with SH(P < 0.05), but these decreased lightly in serious OA group(P > 0.05). SH had mild effect on the contents of NO. Three months after treatment, only in mild OA group the contents of NO significantly decreased (P < 0.05), and no significant change in moderate and serious groups was observed (P > 0.05). CONCLUSION: SH intra-articular injection has a positive effect on the relief of clinical symptoms and on the improvement of articular function of knee OA. The therapeutical effect of SH on OA is achieved possibly by decreasing the contents of free radicals especially oxygen free radicals and inflammatory factors in joint fluids.