Safety and Efficacy of Intra-articular Ozone Injections for Knee Osteoarthritis

Inclusion Criteria: * 55 to 79 years of age * Symptomatic Knee osteoarthritis * VAS pain intensity is at least 40 mm on a 100 mm scale * Must be physically and mentally willing and able to comply with post-operative rehabilitation and routinely schedule clinical and radiographic visits. Exclusion Criteria: * Any known tumor of the ipsilateral knee. * Any known infection of the treated knee. * Osteoarthritis of the operated knee Kelgren Lawrence \< grade 2. * Chemotherapy treatment in the past 12 months. * Patients who are sensitive to ozone. * Pregnant women, or breastfeeding women. * Evidence of any significant systemic disease (such as but not limited to HIV infection, hepatitis infection or HTLV infection), known coagulopathies, that might compromise the Subject's welfare. * Substance abuse or alcohol abuse. * Participation in other clinical trials in parallel to this study.