Abstract: A method for positioning a digital template of a prosthesis based on computerized measurement of the width of the medullar space in an 2-dimensional projection image of the relevant bone into which the prosthesis is to be inserted, the method comprising detecting, preferably automatically, the edges of the medullar space, the edges being detected in a region of interest; determining a position of the template along, such as parallel to, the main bone orientation in such a manner that one or more points on the template and one or more other points in the image has a pre-defined geometrical relationship; and determining an orientation of the digital template and a position orthogonal to the main bone orientation such that the contours of the templates fit the detected edges of the medullar space.

Abstract: A method and a system to be used pre-operatively to obtain guidance in the proper dimensions and model of implants to be implanted in a living body is described. The method includes the steps of determining a diameter of a template of a cup portion of a body part, determining a position of a center of said cup portion in an image of said body part, determining an orientation of said body part, and determining a location of a shaft of a bone associated with said body part. A system for performing the method is described.