Abstract: A method for computer-assisted medical navigation and/or pre-operative treatment planning includes detecting the current position of a patient or a part of a patient's body and the positions of medical treatment devices or treatment-assisting devices. The detected positional data can be assigned to body structure data, in order to jointly use the body structure data in assignment with the positional data, within the context of assisting the treatment. The body structure data can be used which is obtained based on a three-dimensional generic model, where the model is adapted by two-dimensional data linking with patient-characteristic, two-dimensional detection data.