Inclusion Criteria:  Patients suffering from moderate to severe unilateral ankle arthrosis (grade 1-3 according to Giannini's classification); Patients who gave written informed consent to participate in the study; .Patients with MRI examination showing absence of osteochondral lesion; Patients who have given their willingness to come to the Institute for follow-up visits  Exclusion Criteria:  Patients with BMI>30 kg/m2 Patients with Rheumatoid Arthritis Patients with chronic inflammatory joint disease; Patients with acute or chronic infections; Patients with pre-existing abnormalities of gait kinematics (amputations, neuro-muscular diseases, poliomyelitis, hip dysplasia); Patients with severe knee arthrosis (Kellgren-Lawrence>3); Patients with ankle deformities greater than 8°; Patients with pain on other joints of the foot; Patients with severe postural instability; Patients with cognitive deficits; Patients with concomitant neurological pathologies