A surgical navigation system for providing computer-aided surgery. The surgical navigation system includes a handheld surgical tool with computer-aided navigation, an imaging device, an alignment module, and a user interface module. The handheld surgical tool includes at least one sensor for measuring a position of the tool in three dimensions, and at least one set key. A processor and at least one display device are associated with the handheld surgical tool and configured to display a target trajectory of the handheld surgical tool for the surgical procedure.
