The invention relates to 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, comprising: (i) a robotic device (100) comprising: —a cutting tool, —an actuation unit (4) having a serial architecture comprising from three to five motorized degrees of freedom, at least two of said motorized degrees of freedom being rotational degrees of freedom about respective rotation axes that are substantially orthogonal to each other, configured for adjusting a position and orientation of the cutting tool relative to each target plane, —a planar mechanism connecting the last segment of the actuation unit to the cutting tool; (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, (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.