The invention relates to a method for computer-assisted medical navigation and/or pre-operative treatment planning, wherein 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 are detected by means of a position detection unit, and wherein said detected positional data are assigned to body structure data, in order to jointly use said body structure data in assignment with said positional data, within the context of assisting the treatment, wherein body structure data are used which are obtained based on a generic model which has been adapted by linking it with patient-characteristic detection data.