Eligibility Criteria:
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.