A system (10) for tracking a bone-altering tool (14) in computer-assistedsurgery, comprising a first trackable reference (20) secured to a first bone(12), with a first frame of reference being associated with the firsttrackable reference (20). A bone-altering tool (14) is securable to the firstbone (12) in a secured configuration. Sensors (26) track the trackablereference (20) for position and orientation. A position/orientation calculator(34) is connected to the sensor device (26) to calculate a position andorientation of the first frame of reference. An alteration parametercalculator (38) is associated with the position/orientation calculator (34) todetermine a position and orientation of the bone-altering tool (14) in thesecured configuration as a function of the position and orientation of thefirst frame of reference and of the secured configuration. A method (100) fortracking tools using the tracking of a bone is provided.
