1. A method for stereotactic surgery, comprising: implanting a main implant coupled to a reference body in a region of interest of a portion of an anatomy of a subject, the reference body having at least four radiopaque fiducial markers arranged in a three-dimensional pattern, the reference body being in a known spatial relationship with the main implant, the fiducial markers detectable by a fluoroscopic imaging system, the fiducial markers arranged in a pre-determined pattern in the reference body such that the fiducial markers identify a specific main implant and the associated reference body; taking fluoroscopic images of the main implant and the reference body together with the region of interest at two or more angles to obtain a plurality of two-dimensional fluoroscopic images and registering the images using the reference body; processing only the plurality of two-dimensional fluoroscopic images to produce a three dimensional reconstruction of the region of interest using the location of the fiducial markers in the reference body; determining the dimensions and location of the main implant in the region of interest exclusively from the plurality of fluoroscopic images of the reference body associated with the main implant; associating, based on the three dimensional reconstruction of the region of interest, a virtual representation of a not yet implanted sub-implant with the region of interest and the reference body, the main implant and the sub-implant having a fixed predefined spatial relationship to one another upon implantation; and displaying the association as an image showing the virtual representation of the not yet implanted sub-implant superimposed on the reconstructed region of interest such that the not yet implanted sub-implant is displayed as having a virtual fixed predefined spatial relationship to the main implant that is the same as the fixed predefined spatial relationship between the main implant and the sub-implant upon implantation.