[Efficacy and safety of intraarticular injections of hyaluronic acid in knee osteoarthritis: clinical and ultrasonographic evaluations]

Abstract

Objectives: To evaluate the efficacy and safety of hyaluronic acid (HA) therapy in patients with osteoarthritis of the knee.

Materials and methods: We performed a prospective, multicenter, noncontrolled study with a 6-month followup. One hundred eleven outpatients with a diagnosis of knee osteoarthritis based on clinical and radiological criteria (except for Kellgren grade IV) were enrolled in the four participating centers. Five sequential intraarticular injections of HA (Adant(®), Tedec-Meiji Farma, S.A.) were administered over a 4-week period. Efficacy was evaluated at the follow-up visits (2, 12 and 24 weeks after the final injection) by comparing posttreatment with baseline scores for the following variables: overall knee pain on a visual analog scale, Lequesne Index, WOMAC Index, patient and investigator overall assessment of efficacy on a 5-point Likert scale, knee range of movement, and analgesic consumption. Knee ultrasonography was performed at baseline and at the end of the study. Safety was evaluated by systematic recording of adverse events (AE).

Results: A statistically significant improvement in all the efficacy variables analyzed (p≤0.01) compared with baseline values was found at each of the follow-up visits. At 24 weeks, more than 68% of the patients rated their status as better or much better. The presence and amount of intraarticular fluid in the knee joint, assessed by ultrasonography, diminished dramatically after HA treatment. Most of the adverse events were local and were mainly due to the administration technique; the incidence of AEs due to injection was 2.4%.

Conclusion: Intraarticular administration of HA is an effective, safe and well-tolerated alternative in the treatment of mild-to-moderate osteoarthritis with symptomatic improvement lasting up to 6 months.