| 摘要 |
<p>The present invention relates to a bone fixation assembly for securing a fixation device (10), such as a bone plate, to bone. The assembly includes the fixation device (10), a bushing (14), a fastening screw (32), and a locking screw (34). The bushing (14) is seated within a through hole (12) in the fixation device (10) and can rotate within the through hole (12) and has a sidewall (20) with a bore (24). The sidewall (20) has at least one slot (28; 28a) for allowing outward expansion of the sidewall (20) against the through hole (12) to thereby lock the bushing (14) at a selected angle relative to the axis of the through hole (12). The fastening screw (32) has a threaded shaft (36) for insertion through the bore (24) of the bushing (14) and threads into bone to secure the bushing (14) and fixation device (10) to bone. The head (38) of the fastening screw (32) fits in the bushing (14) and includes a radial wall (44) and open end defining a recess (50). The radial side wall (44) has at least one slit (46) for allowing outward expansion of the radial wall (44) thereby outwardly expanding the sidewall (20) of the bushing (14). The locking screw (34) has a body that threads in the head (38) of the fastening screw (32) to thereby outwardly expand the radial wall (44) of the fastening screw (32).</p> |
