Background: Intra-articular injection of hyaluronic acid is widely used as a treatment for osteoarthritis of the knee. The recommended dosing regimens have generally ranged from 3 to 5 injections.
Objective: To assess efficacy and safety of a single intra-articular injection of 2% sodium hyaluronate plus 0.5% mannitol in patients with symptomatic osteoarthritis of the knee.
Material and Method: Twenty patients between 40-70 years of age with osteoarthritis of the knee (Kellgren-Lawrence grade II or III) were included in the study. After a 2-week NSAIDs washout period, ten patients in the intervention group received a single intra-articular 2 ml dose of the combination of 2% sodium hyaluronate and 0.5% mannitol and ten patients in the control group received no injection. No other pain-killer medication was allowed during the study except diclofenac as rescue pain medication in both groups. The efficacy parameters were the WOMAC Index and diclofenac consumption. All adverse events were recorded.
Results: Patients who received a single intra-articular injection of 2% sodium hyaluronate plus 0.5% mannitol had a significant improvement from baseline in all WOMAC subscales over 24 weeks (p<0.001). Pain, stiffness, and physical function subscales were significantly lower in the intervention group than in the control group until Week 20, 12, and 16, respectively (p<0.05). Patients who received sodium hyaluronate also required significantly lower amounts of diclofenac (p<0.05). No serious adverse event related to the intervention was reported.
Conclusion: Symptomatic OA knee patients who received a single intra-articular injection of 2% sodium hyaluronate plus 0.5% mannitol had better outcomes over the 24-week follow-up period than control group patients who received no injection intervention.

Keywords: Osteoarthritis, Hyaluronic acid, Viscosupplement, Intra-articular injection