A system for assessing the relative pose of an implant and a bone of a creature, comprising: a) a medical imaging device for acquiring one or multiple medical X-ray image(s) of the bone with the implant preliminarily mounted to the bone during a surgery; b) a database comprising virtual 3D implant models and means for selecting the kind of implant used wherein the system is adapted to generate, out of the database comprising virtual true to real world scale 3D implant models, a set of virtual 2D images of they kind of implant used, each virtual image being a reproduction of the virtual 3D implant model and a virtual 3D bone model taken from a different pose; c) a calculation means for fitting the virtual implant to the medical X-ray image wherein for the fitting the computing device being further enabled to compare the medical image to the set of virtually generated images in order to identify at least one virtual image showing a match of the pose of the 3D implant model with the implant and the computing device being further enabled to align and visualize the medical image with the identified matching virtual image, thereby linking the pose of the at least one medical image and the 3D pose of the 3D implant model; d) means for selecting a bone model; and e) the calculation means being further enabled to fit the chosen bone model to the medical X-ray image and wherein the computing device being further enabled to insert virtual screws and/or other attachments for fixing the virtual implant according to the actual position of the real implant and comparing the orientation and/or position of the virtual screws and/or other attachments with a desired position of the real screws prior to their insertion into the patient's bone. a) a medical imaging device for acquiring one or multiple medical X-ray image(s) of the bone with the implant preliminarily mounted to the bone during a surgery; b) a database comprising virtual 3D implant models and means for selecting the kind of implant used wherein the system is adapted to generate, out of the database comprising virtual true to real world scale 3D implant models, a set of virtual 2D images of they kind of implant used, each virtual image being a reproduction of the virtual 3D implant model and a virtual 3D bone model taken from a different pose; c) a calculation means for fitting the virtual implant to the medical X-ray image wherein for the fitting the computing device being further enabled to compare the medical image to the set of virtually generated images in order to identify at least one virtual image showing a match of the pose of the 3D implant model with the implant and the computing device being further enabled to align and visualize the medical image with the identified matching virtual image, thereby linking the pose of the at least one medical image and the 3D pose of the 3D implant model; d) means for selecting a bone model; and e) the calculation means being further enabled to fit the chosen bone model to the medical X-ray image and wherein the computing device being further enabled to insert virtual screws and/or other attachments for fixing the virtual implant according to the actual position of the real implant and comparing the orientation and/or position of the virtual screws and/or other attachments with a desired position of the real screws prior to their insertion into the patient's bone.