Early detection of knee osteoarthritis can be achieved by identifying early compositional changes of degenerative articular cartilage. The purpose of this case-control longitudinal study is to validate DTI as a biomarker for OA diagnosis, staging and progression in early stages of the disease. 60 patients with incipient OA (KL1) underwent 3 visits (baseline, 1.5 year and 3 years follow up). Clinical evaluation, Xray and MRI was performed. Positive correlation was demonstrated with morphological changes (KL and WORMS score). In addition, DTI showed changes in the follow up at 1.5 years that were not apparent in clinical MRI.