Exploratory Non Comparative Study to Evaluate the Efficacy of Highly Bioavailable Curcumin (Flexofytol) in Patients With Knee Osteoarthritis

Inclusion Criteria: * 45 to 80 years of age * Internal femorotibial gonarthrosis responding to the clinical and radiological criteria of ACR * Symptomatic knee for more than 6 months * Mean knee pain on the last 24 hours of at least 40 mm on VAS * Kellgren \& Laurence grade II to III * Patients able to avoid NSAIDs and analgesics during the study * Patients having signed informed consent * Patients able to follow the study instructions Exclusion Criteria: * Related to the osteoarthritis pathology: * Osteoarthritis linked to a metabolic arthropathy * Predominant associated symptomatic femoropatellar osteoarthritis * Chondromatosis or villonodular synovitis of the knee * Recent trauma (\< 1 month) of the knee responsible for the pain * Inflammatory flare * Pathology potentially interfering with the evaluation (metabolic inflammatory arthropathy, rheumatoid arthritis, lower limb radiculalgia, arthritis... * Paget disease * Homolateral coxarthrosis * Articular Prosthesis * Knee joint effusion * Related to previous and associated treatments: * Corticosteroids injection in the previous month, whatever the joint concerned, * Hyaluronan injection in the evaluated knee during the previous 6 months, * NSAID or analgesics in the 72 hours prior to inclusion * No modification of Slow-acting drugs for OA and/or dietary supplements taken within less than 6 months prior to the study(ex: chondroitin sulfate, diacerein, soy and avocado unsaponifiables, oxaceprol, granions de cuivre, glucosamine, phytotherapy for OA, homeopathy for OA...), * Anticoagulant (coumarinic) treatment and heparin * General corticotherapy, * Contraindication to paracetamol. * Related to associated pathologies: * Patient suffering from serious associated illness (liver failure, kidney failure, non-controlled cardiovascular diseases...) * Related to patients: * Pregnant or breastfeeding women * Pre-menopausal women with no contraception * Patients unable to write * Patients enrolled in a clinical trial in the previous 3 months * Patients under juristic protection or under guardianship.