Assessment of Preoperative and Postoperative Ankle Kinematics

Inclusion Criteria: * Candidates for ankle prosthesis * Potential party able to provide informed consent and sign the approved Informed Consent Form; * Male or female patients aged 40 to 80; * Patients available to perform post-operative rehabilitation according to standard protocol, follow-up visits and radiological investigations scheduled for follow-up up up up to 24 months. In addition, patients who are available to perform all study tests, preoperators and follow-up. Exclusion Criteria: * Previous total prosthetic replacement of the ankle (revision surgery); * Severe pre-operative deformity in valgus or varus (\>10 sanguine); BMI\>40 kg/m2; * Pre-existing abnormalities of walking kinematics (amputations, neuro-muscular diseases, polio, hip dysplasia); * Severe arthrosis of the knee (Kellgren-Lawrence\>3); * Severa coxartrosi (Kellgren-Lawrence\>3); * Previous hip and/or knee prosthesis surgery; * Total avascular astragalus necrosis or other severe bone loss of the ankle that makes the implantation of standard prosthetic components contraindicated; * Pregnancy confirmed by positive hcg serum or in vitro diagnostic test or ongoing breastfeeding; * Active or latent infection of the affected ankle joint or any other systemic infection being treated; * History of alcoholism, drug or substance abuse intravenously, psychosis, personality disorder/s, poor motivation, emotional or intellectual problems that could make the potential subject unstable for participation in the trial, or any combination of variables which in the opinion of the Principal Investigator should exclude the potential subject; * Clinically documented acute or chronic pathology, other than the indication for the treatment adopted in this Trial, which could affect life expectancy or make it difficult to interpret the outcome of the potential subject in accordance with the Protocol (e.g., renal, hepatic, cardiac, endocrine, haematological, autoimmune, bone metabolism, crystal deposits or neoplasms); * Potential subjects with medical conditions that interfere with the ability to participate in a standardized rehabilitation program; * Participation in any other trial of another drug or experimental device within 60 days prior to the screening visit or administration of that drug or device during the course of this trial.