The purpose of this study is to determine whether MM-II is effective in the treatment of osteoarthritis, in direct comparison with an approved hyaluronic acid preparation.

Osteoarthritis (OA) is the commonest form of joint disease, characterized by articular cartilage degradation with an accompanying periarticular bone response and a synovial membrane inflammation. Clinical manifestations of OA in the knee include pain in and around the joint, stiffness of the joint after rest, crepitus on motion and limited joint. MM-II medical device was designed to reduce wear and lower friction in knees of osteoarthritis patients by creating a lubricating layer onto cartilage surfaces upon injection. The purpose of this study is to determine whether a medical device MM-II is effective in the treatment of osteoarthritis, in direct comparison with an approved hyaluronic acid preparation.

Inclusion Criteria:

• Symptomatic unilateral knee tibiofemoral OA
• Radiographic evidence of knee OA of Kellgren-Lawrence Grade II or III in one or both knees on a recent 3 months time X-Ray
• Knee pain within the last 24 hours before assessment more than 40mm on VAS
• Pain on most days in the last month

Exclusion Criteria:

• Knee pain equal or more than 80mm on a 100mm VAS.
• Pain in the contra lateral knee; more than 30mm on a 100 VAS.
• Concomitant inflammatory joint disease (e.g. gout, rheumatoid arthritis, history of Reiter's syndrome, psoriatic arthritis and ankylosing spondylitis.
• Any condition that may interfere with the measure of pain in the targeted knee
• Concomitant meaningful synovial fluid effusion
• Post trauma OA
• Gross ligamentous instability of the knee