A computer-assisted surgery system comprises a first surgical device with a tracking unit tracked during a surgical procedure and adapted to perform a first function associated to the surgical procedure. A second surgical device is adapted to perform a second function associated to the surgical procedure. A triggered unit is triggered when the first surgical device and the second surgical device reach a predetermined proximity relation. A surgical procedure processing unit tracks the first surgical device. A trigger detector detects a triggering of the triggered unit. A CAS application operates steps of a surgical procedure. A controller commands the CAS application to activate a selected step associated with the second function in the surgical procedure when the trigger detector signals a detection. An interface displays information about the selected step in the surgical procedure.