Dose-Response Effect of Intra-Articular Ozone in Knee Osteoarthritis

The goal of this clinical trial is to evaluate the clinical efficacy of different doses of intra-articular ozone injections combined with exercise in patients aged 40-75 diagnosed with Grade 2-3 knee osteoarthritis. The main questions it aims to answer are: * Which intra-articular ozone doses (10 µg/mL, 15 µg/mL, or 20 µg/mL) is most effective in improving pain and physical function in knee osteoarthritis? * Do combined ozone and exercise therapies provide superior clinical outcomes compared to exercise therapy alone? Researchers will compare four groups (Ozone 10 µg/mL + Exercise, Ozone 15 µg/mL + Exercise, Ozone 20 µg/mL + Exercise and Exercise Alone) to see the dose-dependent effects of ozone therapy. Participants will: * Complete a structured home exercise program for the duration of the study. * Receive 3 sessions of intra-articular ozone injections (for patients allocated to the ozone groups). * Participate follow-up visits for clinical and functional assessments at baseline (before the procedure), immediately after the 3rd injection session, at 1 month after the last ozone injection, and at 3 months after the last ozone injection.

Inclusion Criteria: * Patients aged 40-75 years diagnosed with knee osteoarthritis according to the American College of Rheumatology 2019 criteria * Grade 2 or 3 knee osteoarthritis based on the Kellgren-Lawrence radiological classification system. * Presence of chronic knee pain lasting for more than 6 months. * Numerical Rating Scale score of 3 or higher during knee-loading activities Exclusion Criteria: * Presence or history of acute knee infection, major knee trauma, or inflammatory arthritis * History of knee fracture or surgical intervention involving the affected knee joint within the last 6 months. * History of intra-articular injections (e.g., corticosteroids, hyaluronic acid, PRP) into the affected knee joint within the last 6 months. * History of physical therapy or rehabilitation in the knee region within the last 6 months * Presence of osteomyelitis adjacent to the knee joint, bacteremia, or hemarthrosis. * History of malignancy involving the lower extremity. * Known hypersensitivity or allergy to medical ozone. * Severe anemia, thrombocytopenia, active bleeding disorders, or ongoing anticoagulant therapy. * Pregnancy or lactation * Active infection * Severe systemic diseases (e.g., advanced cardiopulmonary disease, uncontrolled diabetes mellitus). * Hyperthyroidism or progressive neuromuscular disorders. * Cognitive impairment or inability to cooperate with the assessment tools and study protocol.