A method of performing a surgery is provided including a surgical
navigation system having a tracking system, computer and monitor placed
outside of a sterile field. An input pad and a tracking array attachable
to a surgical instrument or bone are placed into the sterile field along
with a probe having a probe array. The tracking array and the probe array
are acquired by the tracking system and a virtual mouse is activated by
positioning the probe relative to the input pad, thereby causing a mouse
input to the computer with the virtual mouse.