Bone fastening system

A bone fastening system comprises a cannulated screw component (2), a seating component (4) and a holding component (6). The screw component comprises a screw head (8) arranged in the region of a proximal end (10) of the screw component, and an elongate screw shaft (12) extending from the screw head along a longitudinal axis (A) towards a distal end (14) of the screw component. The screw head comprises a proximal surface (20) on a front side facing the proximal end and a distal surface (22) on a back side facing the distal end, at least a portion of said distal surface forming a contact surface (24). The seating component comprises a central opening (26) having an opening diameter (dl) larger than the maximum diameter (ds) of the screw shaft and smaller than the maximum diameter (dh) of the screw head, said seating component further comprising a seating surface (30) intended for abutting against the contact surface and a bottom surface (32) intended for abutting against the bone when the bone fasting system is in a fully engaged state. The holding component is connectable or integrally formed with the seating component and defines an accommodation portion (40) for accommodating the screw head such that the screw component and the seating component are connected in a non-detachable manner while at the same time allowing axial rotation of the seating component with respect of the screw component.