The efficacy of low- and high-molecular-weight hyaluronic acid applications

Objectives: We evaluated the efficacy of viscosupplementation with low- or high-molecular-weight hyaluronic acid (HA) preparations following arthroscopic debridement (AD) in patients with osteoarthritis of the knee.Methods: The study included 45 patients (19 men, 26 women; mean age 53 years; range 41 to 66 years) with Kellgren-Lawrence grade 2-3 osteoarthritis of the knee. Following AD, the patients were randomized to three groups to receive three intra-articular injections of 2 ml hylan G-F 20 (Synvisc, n=16), five intra-articular injections of 2 ml sodium hyaluronate (Hyalgan, n=14), and no injections (controls, n=15). Injections were administered at one-week intervals. All the patients were evaluated with pain, stiffness, and functional capacity scores of the WOMAC (Western Ontario and McMaster Universities) osteoarthritis index before and 6 and 12 months after AD. Results: Two patients and three patients complained of transient pain in Synvisc and Hyalgan groups, respectively. WOMAC scores showed significant decreases in all the groups at 6 and 12 months. There were no significant differences between the three groups with respect to improvement in WOMAC scores at 6 months. However, compared to the control group, differences between pre- and posttreatment scores at 12 months were significantly greater in the Synvisc (p=0.004) and Hyalgan (p=0.003) groups, with no significant difference between the two HA groups (p>0.05).Conclusion: Our findings show that AD is beneficial in osteoarthritis of the knee in patients with appropriate indications, viscosupplementation increases the efficacy of treatment, and that low- and high-molecular-weight HA preparations have similar efficacy.