Pain care in knee osteoarthritis by intra-articular injections of hyaluronic acid (ARTHRUM H 2%): a randomized double-blind controlled trial versus another hyaluronic acid (HYALGAN)

The aim of this study was to compare the efficacy for pain release in knee osteoar-thritis (OA) of three repeated intra-articular (IA) injections of two hyaluronic acid (HA) preparations, ARTHRUM H 2% versus reference treatment HYALGAN, in a non-inferiority, double-blind, controlled trial. Methods. A cohort of 282 OA patients was recruited and randomly assigned into two parallel groups, treated in 19 centers in France. Each patient received 3 HA injections spaced one week apart. The main assessment was to compare WOMAC Pain Index variations from D0 to D180, for both intent-to-treat (ITT) and per-protocol (PP) populations. Secondary criteria included assessments at D90 and D180, adding WOMAC function. Accessory criteria included WOMAC global as well as VAS (0-100 mm) pain assessment (7 items), and handicap assessment by patient or by doctor. Tolerance, concomitant drug uptake and patient satisfaction (4 items) were recorded. Results. For the ITT and for the PP populations, the lower limit of the 95% CI, respectively 4.4 and 4.1 mm, was greater than the predetermined non-inferiority limit -9.7 mm. These results were statistically significant at D180, in ITT (P=0.0002) and PP (P=0.0004) analysis for the WOMAC pain, and similarly for the WOMAC function and most of other criteria. Tolerance and safety were good for both products, supporting NSAIDs uptake reduction. Results were crossed between blind evaluator and investigator, and secondarily analyzed in terms of effect size (ES) (0.49 for pain) and OMERACT-OARSI responders. Conclusion. ARTHRUM H 2% was found significantly non-inferior to HYALGAN for pain release and function improvement, in knee OA patients.