 Ultrasound evaluation will be performed at the target knee in same time points as X-rays by two rheumatologists trained in musculoskeletal ultrasound examination. Additionally, the investigators will assess potential biochemical biomarkers of knee OA structural progression and response to treatment. Measurements will be performed in both serum and urine and, If possible, synovial fluid aspiration will be performed and together with blood and urine samples stored at the Biobanco-IMM Instituto de Medicina Molecular for analysis. Biologic samples collection will be performed at baseline and repeated at the 4th, 12th, 24th, 36th weeks, and then every 6 months. 