• Men or women, age 45–75;
• Medial femoro-tibial gonarthrosis (in case of bilateral OA, the most painful knee was evaluated);
• Responding to ACR criteria (clinical evaluation and radiological);
• Symptoms lasting for more than 6 months;
• Global knee pain evaluation over the last 24 hours > 40 mm (without NSAID or other analgesic for more than 48 hours);
• K&L II to III (Kellgren and Lawrence evaluated within the last 12 months);
• Agreed to banish NSAIDs and analgesics for the duration of the study;
• Signed informed consent;
• Capable of following the study guidelines;
• With health insurance.
Patients with AT LEAST ONE of the following criteria were not enrolled in the study
• OA disease:
o Secondary OA due to metabolic arthropathy: chondrocalcinosis previously
o Known or defined by a calcium border on at least one tibiofemoral joint space, gout,…
o Predominant symptomatic femoropatellar OA;
o Chondromatosis or villo-nodular synovitis of the knee;
o Paget’s disease;
o Ipsilateral coxarthrosis to the known and symptomatic gonarthrosis;
o Recent knee trauma (<1 month) responsible for pain;
o Pathologies that could interfere with evaluation (inflammatory and metabolic arthropathy, rheumatoid arthritis, lower limb radiculalgia, arteritis,…).
o Joint prosthesis (any site)
o Flare affecting another joint
• Related to anterior and associated treatments:
o Corticosteroid infiltration received to any joint in the month prior enrollment;
o Infiltration of hyaluronic acid in the evaluated knee within 6 months before enrollment;
o Taking NSAIDs or analgesics in the last 48 hours prior to inclusion;
o No changes in their slow-acting anti-OA drugs and anti-OA dietary supplements over the last 6 months (e.g. chondroitin sulfate, diacerein, avocado soybean unsaponifiables, oxaceprol, copper, glucosamine , anti-OA herbal therapy and homeopathy, …);
o Taking coumarin anticoagulants and heparins;
o General corticosteroid;
o Contraindication to paracetamol.
• About the product:
o Contraindication to the product (Flexofytol)
• Related to associated pathologies:
o Serious associated diseases (severe liver failure, renal failure, uncontrolled cardiovascular diseases, …).
• Regarding the patients:
o Pregnant or lactating women;
o Premenopausal women not using a contraceptive method;
o Patient unable to write;
o Patient who participated in a clinical research in the previous 3 months;
o Legally responsible adults.