Is hyaluronate sodium effective in the management of knee osteoarthritis? A placebo-controlled double-blind study.

AIM: The aim of this study was to investigate the effect of intra-articular hyaluronic acid (HA) injection on pain and function in knee osteoarthritis (OA).

METHODS: Fourty-eight patients with knee OA were included in this study. The patients were randomized into two groups: one group received HA injections (average molecular weight [MW] 1.5 million Da), and the other group received placebo containing 0.9% saline. Three injections of HA or placebo were given at weeks 1, 2 and 3. The evaluation instruments were: Visual Analog Scale (VAS); Likert Scale; Lequesne <ndex; the Western Ontario and McMaster Universities (WOMAC) Index for Osteoarthritis pain, stiffness, and function, and WOMAC pain subgroups (pain on walking, climbing stairs, at night, on sitting and lying down, on standing); the number of analgesics taken; changes in knee flexion angle; and patient satisfaction. Assessment was performed at weeks 1, 3, 5, and 14 after the first injection.

RESULTS: Significant improvement for almost all parameters was noted in both groups (P <0.05). There was no statistically significant difference between change in outcome after HA or placebo treatment (P >0.05), except for WOMAC pain subscore on walking at final assessment (week 14) which showed greater improvement in the HA-treated group (35.2% versus 9.1%; P=0.01).

CONCLUSION: HA treatment was effective in the management of knee OA and improved knee pain and functional outcome, but there was no statistically significant difference in functional and symptom improvement with respect to saline (placebo) injection.