Cellular Matrix Device for the Treatment of Mild to Moderate Knee Osteoarthritis

Inclusion Criteria: * femorotibial knee osteoarthritis defined according to the American College of Rheumatology (ACR) criteria * Symptomatic knee osteoarthritis of a unilateral knee, characterized by pain at walking (WOMAC A1 score assessed over the previous 24 hours on a 100-mm Visual Analog Scale (VAS): 50 ≤ WOMAC A1 ≤ 90) or reduced joint function (total WOMAC C score assessed or over the previous 24 hours on a 100-mm VAS: 50 ≤ WOMAC A1 ≤ 90) * Bilateral knee osteoarthritis is allowed, provided the contralateral knee is characterized by a maximum pain of 30 on a 0 to 100 mm scale and doesn't require systemic analgesic treatment, with the exception of paracetamol up to the maximum dose of 4 g per day * Radiographic femorotibial knee osteoarthritis (radiograph not older than 3 months) Kellgren \& Lawrence grades of II-III * Outpatient capable of walking 50 meters without assistance * Signature of the informed consent form * Capable of understanding the study's imperatives, as well as written instructions * Capable of filling-out evaluation questionnaires Exclusion Criteria: * Radiographic femoro-tibial knee osteoarthritis Kellgren \& Lawrence grades of I or IV * Bilateral knee osteoarthritis, characterized by pain greater than 30 of both knees evaluated on a 0 to 100-mm scale and requiring systemic analgesic treatment or paracetamol greater than 4g/ day * Viscosupplementation in the past 3 months * Corticosteroid injection in the past 3 months * PRP or PRP/HA injection in the past 12 months * Any surgery of the knee planned during the next 6 months * Systematic use of corticosteroids (except those that are inhaled) or level III analgesics in the past 3 months and NSAID (non-steroidal anti-inflammatory drugs) during the past month * Treatment with slow-acting anti-rheumatic drugs (diacerhein, soybean or avocado unsaponifiables, chondroitin sulfate, glucosamine) started in the past 6 months * History of allergy to hyaluronic acid * Auto-immune disease (rheumatoid arthritis, lupus) * Surgery of the affected knee in the past 3 months * Infection of the affected knee in the past 6 months * Rheumatologic disorder other than arthritis * Clinical evidence of local inflammation such as redness or heat of the joint * Hereditary or acquired hematologic or clotting disorders, such as drepanocytosis, platelet dysfunction, thrombocytopenia (\<150'000 platelets/mm3), etc. * Anemia (Hemoglobin \< 10g/dl) * Anticoagulant treatment (patients under antiaggregant treatment can take part to this study as long as their clotting time (CT) is within the reference value) * Acute infection * Malignant disease (especially bone and hematological * serious disorders (cardiovascular pathology, active gastroduodenal ulcer, digestive hemorrhage) * Patient with renal impairment (creatinine clearance below 45 ml / min) * Patient with liver failure, pending or who have recently received a liver transplant * Pregnancy or breastfeeding or planning pregnancy during the course of the study * Immunosuppression * Insulin-dependent diabetic patient * Participation ongoing or in the past 3 months in another clinical study * Participation to another osteoarthritis clinical study during the past year * Patient unable to submit to the constraints of the protocol, including patient whose mental condition does not allow him to understand the nature, objectives and possible consequences of the study * Any other reason which, in the opinion of the investigator, may interfere with the proper conduct of the study