Customized Biomechanical Models of the Musculoskeletal System Before and After Surgery

Inclusion criteria: * Men or women aged 20 to 65 years * Patients who have had orthopaedic surgery * Presence in the file of a preoperative CT scan and/or magnetic resonance imaging (MRI) * Presence in the file of a CT scan and/or MRI postoperatively at a distance from the operation (at least 4 weeks) * Presence in the file of an operating report describing the procedure in detail with access routes, operating times, type of equipment and possible complications. * Patient who has authorized the anonymous use of data from his pre and post surgical examinations * Patient who is a member of a social security organisation Criteria for non-inclusion: * Patient who has expressed his refusal to use his medical data * Minor, patient under guardianship, inability to receive information and express consent * Pregnant women * Non-affiliation to a social security scheme (beneficiary or beneficiary) * Examinations of images that do not allow 3D reconstruction of structures (poor resolution or type of sequence) * Incomplete operating report not allowing the understanding of the steps of the surgery. * Surgical report describing surgery that does not represent the usual procedures performed.