| 摘要 |
The invention concerns a fixation apparatus comprising a holder (2′) and a tension sleeve (4′) receiving a bone screw (1′), wherein the bone screw (1′) has a shaft (10′) with a front thread (11′) and a head (12′) at the rear end, and the holder (3′) has a through borehole (30′) with a receiving seat (32′), in which the tension sleeve (4′) is mounted and able to swivel, while the shaft (10′) has a thickening (15′) in a rear region, to the front of the head (12′), whose width increases toward the head (12′), and the width of the tension sleeve (4′) is larger than the width of the shaft (10′) immediately before the thickening (15′) and smaller than the greatest width of the thickening (15′). When screwed in, the thickening (15) widens the tension sleeve (4′) so that it is pressed by its envelope against the wall of the receiving seat (32′). In this way, an angle-stable pressing is achieved for any given orientation of the bone screw (1′). |
