[The efficacy of low- and high-molecular-weight hyaluronic acid applications after arthroscopic debridement in patients with osteoarthritis of the knee].

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.