To compare the effects of a single intra-articular injection of a novel polyvinyl alcohol preparation (PVA Hydrogel) and hylan G-F20 (Synvisc-One®) in patients with symptomatic knee OA.~Patients with knee OA (ACR clinical and radiological criteria) symptoms for ≥6 months, insufficient/failed response to analgesics, K&L stage II-III (x-Rays within past 12 months), a knee pain score of 4-9 (0-10 NRS) in the target knee and <3 in the contralateral knee, will be enrolled in a randomised, controlled, double-blind, parallel group 26-week clinical investigation to receive a single intra-articular injection of PVA Hydrogel or Synvisc-One®. Safety (both at the injection site (primary end-point) and overall) and efficacy (change in pain in the target knee (0-10 NRS), WOMAC Osteoarthritis Index (total and subscales) and Patient's Global Assessment of knee OA (0-10 NRS)) will be evaluated.~After signing an informed consent, patients will be screened at least 7 days before randomisation, when they will received a single intra-articular injection of either PVA Hydrogel or Synvisc-One® (1:1 allocation ratio) and will be then seen for follow-up 1, 2 and 4 days (this latter just in case of AE occurrence at the target knee) and 2, 4, 8, 12, 18 and 26 weeks after IA injection.
This multicentre, prospective, randomized, double-blind, active-controlled, parallel group clinical investigation is aimed to assess the safety and the clinical performance over 6 months of a single intra-articular injection of PVA Hydrogel, novel polyvinyl alcohol preparation, as compared to hyalan G-F20, (Synvisc-One®) one of the most commonly used and best performing hyaluronic acid based products, in patients with symptomatic knee osteoarthitis (OA).