Intra Articular Injection of Peripheral Blood Mononuclear Cells for Knee Osteoarthritis

Inclusion Criteria: * Tibiofemoral osteophytes on x-ray (Kellgren-Lawrence grade of 2-4) * Age ≥ 40 and ≤ 80 years. * Moderate to severe knee pain * Reduced joint space width at the medial part of the knee compared to the lateral part under x-ray examination. If standing is not feasible, the same supine position must be used consistently for follow-up. * A minimal pain score of 5 measured by both NRS and VAS when walking last week. * Knee pain on most days (no less than 15 days) in the 4 weeks before screening * Patients have experienced that NSAID or opioid pain medication failed to control knee pain in the last year. * Patients have experienced that a single intra-articular injection of medicines, such as steroids, hyaluronic acid, or platelet-rich plasma, failed to control the knee pain over 6 months. * Non-invasive treatments did not control the knee pain. Conservative and non-invasive treatment regimens may include any or all of the following: initial rest, muscle relaxants, massage, and oral medications, e.g., anti-inflammatory drugs, analgesics, narcotics/opioids. * The patients have taken supervised physical and rehabilitation therapy, such as daily walking routines, therapeutic exercises, sonication, heat/cold therapy, and electric stimulation for knee pain control within the last year. Exclusion Criteria: * Patients who have taken knee, distal femur, or proximal tibia surgery. * Patients who took an intra-articular injection of medicine, such as steroids, hyaluro…