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.