A surgical system for cutting an anatomical structure (F, T) of a patient according to at least one target plane defined in a coordinate system of the anatomical structure comprises:(i) a robotic device (100) comprising:- an end effector comprising a cutting tool or a cutting block,- an actuation unit (4) comprising from three to five motorized degrees of freedom, attached to the end effector, configured for adjusting a position and orientation of the cutting tool or cutting block relative to each target plane,(ii) a passive articulated lockable holding arm (5) supporting the actuation unit (4)；(iii) a tracking unit (200) configured to determine in real time the pose of the cutting plane with respect to the coordinate system of the anatomical structure, the tracking unit comprising a tracker configured to be rigidly attached to the actuation unit and a tracker configured to be rigidly attached to the end effector；(iv) a control unit (300) configured to determine the pose of the cutting plane with respect to the target plane and to control the actuation unit so as to bring the cutting plane into alignment with the target plane.
