Background/purpose: Intra-articular injection of hyaluronan (hyaluronic acid; HA) products is available to treat early osteoarthritis (OA) of the knee in Taiwan. We tested whether HA products with different molecular weights have significantly different effects on clinical efficacy and cost-effectiveness.
Methods: Thirty-seven patients with mild to moderate OA of both knees underwent five weekly intra-articular injections of sodium hyaluronate (Artz) in one knee and three weekly intra-articular injections of chemically cross-linked Hylan G-F 20 (Synvisc) in the other. Visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lequesne's index, and Hospital for Special Surgery (HSS) knee scores were compared initially and at the last injection, and at 8, 12, 16, 20, and 26 weeks after the first injection.
Results: VAS, WOMAC, WOMAC-A1 (pain when walking on a flat surface) scores before week 16, HSS scores before week 12, and Lequesne's index scores except at week 26 all showed that HA significantly improved the scores time-dependently. In VAS scores, Synvisc showed better improvement before week 20, while this effect appeared at week 12 for the WOMAC-A1 scores. The incremental cost-effectiveness ratio of the Taiwan National Health Insurance Program, of the patient, and both of these was lower for Synvisc, which also reduced the number of additional hospital visits for injections by two.
Conclusion: Synvisc possesses better symptom-modifying ability and cost-utility in treating early OA of the knee in Taiwan.