Bone screw, in particular for osteosynthesis
View Patent ↗A bone screw ( 1 ) having a threaded proximal portion ( 2 ), a threaded median portion ( 3 ), and a threaded distal portion ( 4 ). Threaded proximal portion ( 2 ) has a core ( 11 ) with a constant diameter and a proximal thread ( 12 ) with a constant diameter and a proximal pitch (P 2 ). The threaded median portion ( 3 ) has a core ( 15 ), which is conical, with a diameter becoming increasingly larger from the distal end of the threaded median portion ( 3 ) to the proximal end thereof, and thread ( 16 ), which has a constant diameter smaller than the diameter of the thread ( 12 ) of the proximal threaded portion ( 2 ). The pitch of thread ( 16 ) of the threaded median portion ( 3 ) becomes increasingly smaller from the distal end of the threaded median portion ( 3 ) towards its proximal end. At the proximal end of the threaded median portion ( 3 ), the pitch of thread ( 16 ) is larger than the pitch (P 2 ) of the thread ( 12 ) of the threaded proximal portion ( 2 ). The threaded distal portion ( 4 ) has a core ( 17 ) and thread ( 18 ), both having a constant diameter, and with thread ( 18 ) having a diameter that is smaller than the diameter of the thread ( 16 ). The pitch (P 4 ) of the thread ( 18 ) of the threaded distal portion ( 4 ) is larger than the pitch of thread ( 16 ) at the distal end of the threaded median portion ( 3 ).
1. A bone screw ( 1 ) comprising
(a) a threaded proximal portion ( 2 ) having
a proximal core ( 11 ) with a constant diameter and
a proximal thread ( 12 ) with a constant diameter and a proximal pitch;
(b) a threaded median portion ( 3 ) having
a conical median core ( 15 ) with a diameter that becomes increasingly larger from a distal end of the threaded median portion ( 3 ) to a proximal end of the threaded median portion ( 3 ) and
a median thread ( 16 ) with a constant diameter which is smaller than the diameter of the proximal thread ( 12 ) and a median pitch that becomes increasingly smaller from the distal end of the threaded median portion ( 3 ) towards the proximal end of the threaded median portion ( 3 ), the median pitch at the proximal end of the threaded median portion ( 3 ) being larger than the proximal pitch; and
(c) a threaded distal portion ( 4 ) having
a distal core with a constant diameter ( 17 ) and
a distal thread ( 18 ) with a constant diameter that is smaller than the diameter of the median thread ( 16 ) and a pitch that is larger than the pitch of the median thread ( 16 ) at the distal end of the threaded median portion ( 3 ).
2. The bone screw according to claim 1 , further comprising at least one transverse hole ( 20 ) adapted to receive a screw or a pin to prevent rotation of the bone screw relative to a bone portion or fragment ( 100 , 101 ).
3. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is a through hole.
4. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is not a through hole.
5. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is smooth.
6. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is tapped.
7. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is perpendicular to a longitudinal axis of the screw ( 1 ).
8. The bone screw according to claim 2 , wherein the at least one transverse hole ( 20 ) is oblique in relation to a longitudinal axis of the screw ( 1 ).
9. The bone screw according to claim 2 , wherein the bone screw includes at least two transverse holes ( 20 ), one of which is arranged in the threaded proximal portion and the other of which is arranged in the threaded distal portion.
10. The bone screw according to claim 1 , further comprising at least one intermediate portion between the threaded distal portion ( 4 ) and the threaded median portion ( 3 ) or between the threaded median portion ( 3 ) and the threaded proximal portion ( 2 ) or between both.
11. The bone screw according to claim 10 , wherein the at least one intermediate portion ( 5 , 6 ) is flared.
12. The bone screw according to claim 10 , wherein the at least one intermediate portion ( 5 , 6 ) is not flared.
13. The bone screw according to claim 10 , wherein the at least one intermediate portion is threaded.
14. The bone screw according to claim 10 , wherein the at least one intermediate portion is smooth.
15. The bone screw according to claim 10 , further comprising at least one transverse hole ( 20 ) arranged near the at least one intermediate portion.