APPARATUS AND METHODS FOR USE WITH IMAGE-GUIDED SKELETAL PROCEDURES

A procedure is performed with a tool coupled with one or more sensors. 3D image data is acquired of a skeletal portion. First and second x-ray images of the tool and the skeletal portion are acquired from respective first and second views. A computer processor (22) (i) registers the x-ray images to the image data, (ii) identifies a first location of the tool with respect to the skeletal portion, within the x-ray images, (iii) determines the tool's first location with respect to the image data, (iv) subsequently to moving the tool to a second location, obtains measurements by the sensors pertaining to the movement of the tool, (v) derives the second location of the tool with respect to image data by applying the information from the sensors to the determined first location of the tool, and (vi) generates an output. Other applications are also described.