Evaluation of the Efficacy of a Turmeric Extract (Arantal®) in Patients With Osteoarthritis of the Knee (Gonarthrosis).

Inclusion Criteria: * Patient is 40 through 80 years of age * Subject diagnosed with femorotibial osteoarthritis of the knee (diagnosed according to the clinical and radiologic criteria of ACR), * Patient's Assessment of Arthritis Pain measurement on the last 24 hours of at least 50 mm on VAS, * Patient has not received any NSAIDs within 72 hours and any analgesics within 24 hours, * Patients with chronic knee pain (i.e., knee pain at least every other day during the month preceding inclusion), * Patients with radiologic knee osteoarthritis (Kellgren-Lawrence grade 2-4, on radiography less than 12 months old), * Patients having signed the informed consent, * Patients capable of comprehend the study instructions. Exclusion Criteria: * Related to the osteoarthritis pathology: * Osteoarthritis linked to a metabolic arthropathy: chondrocalcinosis already diagnosed or defined by calcium edging on at least one femorotibial joint space, gout..., * Predominant associated symptomatic femoropatellar osteoarthritis, * Chondromatosis or villonodular synovitis of the knee, * Recent trauma (\< 1 month) of the knee responsible for the pain, * Knee joint effusion justifying an evacuation through puncturing, * Inflammatory flare (night pain, joint effusion) corresponding to a KOFUS score less than 7, * Pathology potentially interfering with the evaluation (metabolic inflammatory arthropathy, rheumatoid arthritis, lower limb radiculalgia, arthritis...), * 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, * Patient who took NSAID in the 72 hours prior to inclusion or Analgesics in the 24 hours prior to inclusion, * Slow-acting drugs for OA and/or dietary supplements taken within less than 3 months prior to the study product administration or for which the dose has been modified in the last three months (ex: chondroitin sulfate, diacerein, soy and avocado unsaponifiables, oxaceprol, granions de cuivre, glucosamine, phytotherapy for OA, homeopathy for OA...), * Anticoagulant treatment without gastric protection, * General corticotherapy, * Contraindication to paracetamol. * Related to associated pathologies: * Patient suffering from serious associated illness (liver failure, kidney failure, non-controlled cardiovascular diseases...), * Peptic ulcer. * 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.