A method of operating an image-guided surgical system using imaging information for a 3-dimensional anatomical volume, the method comprising: detecting a pose of a probe based on information received from a tracking system , wherein the probe defines a longitudinal axis and the probe is a physical device which is positioned adjacent to a body ; generating an image of the body that includes a virtual implant using 3D anatomical image information, displaying the image including the virtual implant , a virtual implementation of the probe and a trajectory of the virtual implant , updating the image such that moving the probe adjacent to the body causes the virtual implementation of the probe, the trajectory of the virtual implant, or the virtual implant to move on the image displayed, determining a placement of the virtual implant for the 3-dimensional anatomical volume based on the pose of the probe and based on an offset from an end of the probe along the longitudinal axis, such that the trajectory of the virtual implant is in alignment with the longitudinal axis of the probe in the pose; and after determining the placement of the virtual implant , adjusting the virtual implant responsive to movement of the probe adjacent to the body while maintaining the trajectory of the virtual implant , wherein the determination of the placement of the virtual implant comprises to track the probe , set the trajectory of the virtual implant responsive to a user input and determine the placement for the virtual implant at a default offset along the trajectory , and wherein adjusting the virtual implant comprises moving the placement of the virtual implant along the trajectory responsive to movement of the probe . detecting a pose of a probe based on information received from a tracking system , wherein the probe defines a longitudinal axis and the probe is a physical device which is positioned adjacent to a body ; generating an image of the body that includes a virtual implant using 3D anatomical image information, displaying the image including the virtual implant , a virtual implementation of the probe and a trajectory of the virtual implant , updating the image such that moving the probe adjacent to the body causes the virtual implementation of the probe, the trajectory of the virtual implant, or the virtual implant to move on the image displayed, determining a placement of the virtual implant for the 3-dimensional anatomical volume based on the pose of the probe and based on an offset from an end of the probe along the longitudinal axis, such that the trajectory of the virtual implant is in alignment with the longitudinal axis of the probe in the pose; and after determining the placement of the virtual implant , adjusting the virtual implant responsive to movement of the probe adjacent to the body while maintaining the trajectory of the virtual implant , wherein the determination of the placement of the virtual implant comprises to track the probe , set the trajectory of the virtual implant responsive to a user input and determine the placement for the virtual implant at a default offset along the trajectory , and wherein adjusting the virtual implant comprises moving the placement of the virtual implant along the trajectory responsive to movement of the probe . <EOS>