| 摘要 |
PROBLEM TO BE SOLVED: To provide an orthopedic nut for fixing the end of a bone screw. SOLUTION: The orthopedic nut 10 fixes the end of the bone screw projecting through the bone. The nut 10 has a head part 12 which is at least partly formed of a polymer. The head part 12 has a head 16 of a shape suitable for receiving a torque appliance, such as a standard hexagonal wrench. and rotates the orthopedic nut 10. The polymer is generally compressive to the material used for the bone screw and forms a locking mechanism in the bone screw. Screw threads 26 are formed in the bore of the circular opening of the head part 12 and receives the threads of the bone screw. In addition, the threads 26 may be cut into the head part 12 by the self-tapping bone screw. The compression contact area with the bone may be widened by using the head part 12 together with a washer 14. The washer 14 is produced of a radioactive impermeable material, such as titanium, and is rotatably mounted at the head part 12. Both of the head part 12 and the washer 14 have slaves 28, 32 extending into the bone and make the profile of the nut 10 low.
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