1. A device for referencing a fiducial implant, comprising: a fiducial implant for insertion into a portion of a body, the implant having first and second reference points and a head, the head and the reference points having a known spatial relationship; a pointer having a distal pointer end and at least three emitters configured to emit radiation, the distal pointer end and the emitters having a known spatial relationship; a position finder comprising at least two detectors configured to detect the radiation whereby the position of the emitters in three-dimensional space can be determined; and wherein the head of the implant and the distal pointer end are configured to removably and reproducibly mate to provide a known spatial relationship between the reference points and the distal pointer end to allow the position of the first and second reference points in three dimensional space to be determined.