Inclusion and exclusion criteria

Eligible patients with knee OA-associated pain were included in the present study. Their ages were ≥45 years, diagnosed with painful knee OA based on the American College of Rheumatology criteria (ACR)-1986 guideline.[11] They have mild-to-moderate pain in the Visual Analog Scale (VAS) >40, and their OA complaint lasted ≥6 months with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) index above 50 out of 96 scales at baseline. Patients with rheumatic diseases, autoimmune disorders, immunologic diseases or other chronic pain conditions, malignancy, and earlier knee surgery were excluded.