| 摘要 |
The invention relates to a bone screw (2; 14) with a screw shaft (4; 21) that is anchored in a bone or part of a bone concentrically to the longitudinal axis (5; 24) of a screw and a screw head (3; 22). The inventive bone screw (2; 14) is characterized in that between the screw head (3; 22) and the screw shaft (4; 21) it is provided with a disk- shaped shoulder (6; 23) that is located concentrically to the longitudinal axis (5; 24) of the screw. The diameter of said shoulder is larger than the diameter of the screw shaft (4; 21). The invention further relates to a device for the osteosynthetic bone fixation. Said device comprises (A) at least one bone screw (2; 14) of the above type; and B) at least one slab-shaped, prismatic or cylindrical fixation element (1; 15) which is provided with at least one bore (7; 17) with a center axis (8; 16) for receiving the bone screw (2; 14), and, at the end of the screw shaft, a lower part (9; 19) and at the end of the screw head, an upper part (11; 18). The device is further characterized in that C) the bore (7; 17) comprises a section (10; 26) that tapers towards the lower part (9; 19) and that D) the diameter d of the shoulder (6; 23) has such a dimension that the shoulder (6; 23) can be accommodated in the concave section (10; 26) of the bore (7; 17) at different angles between the longitudinal axis (5; 24) of the screw and the center axis (8; 16) and is placed on the wall (12; 27) of the bore (7; 17).
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