The present invention relates to a system and method for navigating surgical instruments in a patient. The system comprises the components of a first tracking system using a first type of tracker； a second tracking system using a second type of tracker； at least one patient tracker 40 belonging to the first type of tracker measuring the position of the patient； a surgical instrument comprising a tracker 5 belonging to the second type of tracker and at least one geometric primitive of interest； and a connector 15 for rigidly connecting at least one of a first type of tracker with at least one of a second type of tracker for registering the coordinates of the surgical instrument to the coordinates of the image data of the patient and vice versa (or transforming the co-ordinates). The tracking systems may be an optical system and an electromagnetic system, and the connector may be a bone of the patient (see figure 3) or a hybrid tracker instrument 15. A hybrid navigation unit 20 may support both systems simultaneously.
