Jean Dubousset, born in 1936, is an orthopedic surgeon pediatrician, Professor Emeritus of Universities (Université René Descartes). He is a full member of the National Academy of Medicine and the Academy of Surgery. He is a member of the Scientific Council of the Cotrel Foundation of the Institute of France and member of the Scientific Council of the Biomechanics Laboratory of ENSAM Paris Tech. He received the world price of surgery with Yves Cotrel for the work on the 3D correction of the spine, the price of the Academy of Sciences for his work on child malignancies and Maurice Muller Prize for his work on the spine. For Jean Dubousset, Patients, clinicians and engineers are inseparable. Orthopedic surgeon and pure clinician experience of over 35 years of joint work with IT engineers first, then the biomechanics and physics of particles finally, has shown how this multidisciplinary approach was essential to the practical progress for the most important part of the trio: the patient. Starting from the pure clinical observation of such deformation of the spine and noting discrepancies between clinical and radiological imaging associated with surgical failure, the three-dimensional character of the vertebral body, appeared to be a key element into account, measure, individual model, simulation on computer models, correction maneuvers, before making the real surgery. This was extended to the entire musculoskeletal system, where it was necessary to include the essential role of soft tissue in particular muscle and movement and then the nervous system both central and peripheral. Trying to understand before treatment but treatment using the most reliable and best performing technologies including robotics, to reliably measure and control the outcome. All this explains why the clinician has the duty to gather all the skills of the engineering sciences, being the particularly privileged contact with the therapeutic indication and the relationship of mutual trust with the patient which is the basis of medical humanism.