Registry of intra-articular hyaluronic acid in the treatment of knee osteoarthritis in Argentina

Background: Intra-articular treatment of knee osteoarthrosis (OA) with hyaluronic acid (IA-HA) is frequently used in Argentina, with different dosing forms and injection regimens. Our main objective was to provide real world data on the use and effectiveness of IA-HAMethods: In this observational retrospective cohort study we studied 1227 patients with knee osteoarthrosis treated with IA-HA 20mg/2ml weekly (76%-20mg group) and 40mg/2ml (24%-40mg group) according to usual practice intervals. Follow up was at 6 months and efficacy assessed by 5 point Likert scale and 50% or more response rate.Results: Median number of applications was 5 (20mg) and 3 (40mg). Both groups had a significant improvement in the Likert scale from baseline to 6 month. Median score improved from 4 (mean 3.77 ±0.69) at baseline to median of 2 (mean 1.99 ±0.76) at 6 months (20mg group, p <0.001) and from median of 4 (mean 3.65 ±0.65) to median 2 (mean 1.86 ±0.72) in the 40mg group, p <0.001. Proportion of patients with 50% or more 6 month response were 61% and 66% respectively. In the multivariate analysis, 50% response rate was associated with higher baseline score, younger age and shorter duration of disease. Only 1 patient in the 20mg group (0.1%) experienced a serious treatment related adverse event (septic arthritis) following injection.Conclusion: Our study in common clinical practice supports the effectiveness of IA-HA in step management of knee OA with clinical benefit observed at 6 month follow up.