Device for connecting a longitudinal member to a bone
A device to join a longitudinal support ( 3 ) with a bone, in particular with a body of the vertebra, comprising a bone anchoring element ( 1 ) that can be fixed on a bone, a connecting element ( 9 ) provided on the rear end ( 5 ) of the bone anchoring element ( 1 ) with a channel axis ( 27 ) passing through the connecting element ( 9 ) transversely to the central axis ( 2 ) to accept a longitudinal support ( 3 ), tightening means ( 13 ) which can be connected with the free end ( 21 ) of the connecting element ( 9 ) and are suitable for the fixing of a longitudinal support ( 3 ) introduced into the channel ( 25 ), and a tilting element ( 8 ) provided in the channel ( 25 ), said tilting element being rotatable about both the central axis ( 2 ) and the axis ( 7 ) of rotation that is transverse to the axis ( 7 ) of the channel.
1 . A spinal fixation system comprising:
a connecting element having a connecting portion and a bone anchoring portion, wherein the connecting portion has an upper opening, a lower surface, and a channel extending therethrough;
a tightening element insertable through the upper surface and engageable with the connecting portion;
a tilting element disposed in the connecting portion, and having a upper surface and a lower surface, wherein the lower surface of the tilting element is proximate the lower surface of the connection portion; and
a longitudinal member disposed in the channel and proximate the upper surface of the tilting element;
wherein the tilting element is able to rotate relative to the connecting element when the tightening element is not in contact with the longitudinal member; and
wherein the lower surface of the tilting element is configured to securedly engage the lower surface of the connecting portion when the tightening element exerts a downward force on the longitudinal member, thereby fixing the tilting element relative to the connecting portion.
2 . The system of claim 1 , wherein at least one of the lower surface of the tilting element and the lower surface of the connecting portion has a plurality of projections.
3 . The system of claim 2 , wherein at least a portion of the projections are serrations.
4 . The system of claim 2 , wherein at least a portion of the projections are teeth.
5 . The system of claim 1 , wherein both the lower surface of the tilting element and the lower surface of the connecting portion have a plurality of projections, and wherein the projections are substantially complementary between the surfaces.
6 . The system of claim 1 , wherein the lower surface of the tilting element as a plurality of projections configured to penetrate the lower surface of the connecting portion.
7 . The system of claim 6 , wherein lower surface of the connecting portion is comprised of a softer material than the projections.
8 . The system of claim 1 , wherein the lower surface of the connecting portion has a plurality of projection configured to penetrate the lower surface of the tilting element.
9 . The system of claim 8 , wherein the lower surface of the tilting element is comprised of a softer material than the projections.
10 . The system of claim 1 , wherein the lower surface of the tilting element is substantially convex, and the lower surface of the connecting portion is substantially concave.
11 . The system of claim 1 , wherein the bone anchoring portion is integral with the connecting portion.
12 . The system of claim 1 , wherein the tightening element is configured to threadedly engage the connecting portion.
13 . The system of claim 1 , wherein the tilting element further comprises a groove, wherein the connecting portion houses at least one pin engageable with the groove to retain the tilting element within the connecting portion.
14 . The system of claim 13 , wherein the groove is substantially arc-shaped.
15 . A method of securing a spinal fixation system comprising:
(a) providing a spinal fixation system comprising a connecting element having a connecting portion and a bone anchoring portion having a longitudinal axis, a tightening element, and a tilting element disposed in the connecting portion and having a upper surface and a lower surface;
wherein the connecting portion has an upper opening, a lower surface, and a channel extending therethrough;
wherein the lower surface of the tilting element is proximate the lower surface of the connection portion;
(b) inserting at least a portion of the bone anchoring portion into a vertebral body;
(c) inserting a longitudinal element having a longitudinal axis into the channel, such that the longitudinal element is proximate the upper surface of the tilting element;
(d) adjusting the tilting element such that the longitudinal axis of the longitudinal element forms a desired angle with the longitudinal axis of the bone anchoring portion;
(e) manipulating the tightening element, such that the tightening element exerts a downward force on the rod, which in turn exerts a downward force on the tilting member thereby fixing the tilting member relative to the connecting portion.
16 . The method of claim 15 , wherein step (e) further comprises rotating the tightening element relative to the connecting portion.
17 . The method of claim 15 , wherein the bone anchoring portion is integral with the connecting portion.
18 . The method of claim 15 , wherein both the lower surface of the tilting element and the lower surface of the connecting portion have a plurality of projections, and wherein the projections are substantially complementary between the surfaces.
19 . The method of claim 15 , wherein at least one of the lower surface of the tilting element and the lower surface of the connecting portion has a plurality of projections.