Reinforced bone anchor for a dynamic stabilization and motion preservation spinal implantation system and method

1. An anchor assembly comprising:

an anchor body;

an anchor head including a first arm and a second arm extending substantially parallel to one another and away from the anchor body, the first arm and the second arm separated by a gap;

a shaft connected to the first arm and the second arm across the gap;

a saddle having a longitudinal bore, a transverse bore which intersects the longitudinal bore, and a member capture opening adapted to receive a member wherein the member capture opening intersects the longitudinal bore;

said transverse bore of said saddle being mounted about said shaft such that the saddle can move relative to the anchor head;

a set screw received in said longitudinal bore of said saddle and adapted to lock the member in said member capture opening of said saddle; and

said saddle including reinforced walls that prevent said saddle splaying when said set screw locks the member in said member capture opening of said saddle.

2. The anchor assembly of claim 1 wherein said member capture opening is U-shaped with ridges located about said member capture opening so as to prevent splaying of said saddle.

3. The anchor assembly of claim 1 wherein said saddle has flat outer walls.

4. The anchor assembly of claim 1 wherein said saddle includes reinforcing ridges.

5. The anchor assembly of claim 1 wherein said saddle includes a wall with an increasing thickness.

6. The anchor assembly of claim 1 wherein said member capture opening is open to an end of said saddle located distally from said anchor body and said member capture opening is reinforced where said member capture opening opens at the distal end.

7. The anchor assembly of claim 1 wherein said member capture opening is open to a side of said saddle and said member capture opening is reinforced where said member capture opening opens at said side of said saddle.

8. The anchor assembly of claim 7 wherein:

said longitudinal bore is cylindrical with a screw thread and said set screw is cylindrical and includes a set screw thread that mates with the screw thread of the longitudinal bore;

said peripheral wall is thicker where said member capture opening is provided through said peripheral wall; and

said peripheral wall is roof-shaped.

9. The anchor assembly of claim 1 wherein said saddle includes a peripheral wall that is roof shaped.

10. An anchor assembly comprising:

an anchor body;

an anchor head;

a saddle including a first arm and a second arm extending substantially parallel to one another and away from the anchor body, the first arm and the second arm separated by a gap;

a shaft connected to the first arm and the second arm across the gap;

said saddle having a longitudinal bore, a transverse bore which intersects the longitudinal bore;

said saddle including an end located distally from said anchor;

said saddle including a member capture opening that is open to said distal end, said member capture opening adapted to receive a member;

a fastener received in said longitudinal bore of said saddle and adapted to lock the member in said member capture opening of said saddle; and

said saddle including reinforced walls that prevent said saddle splaying when said fastener locks the member in said saddle.

11. The anchor assembly of claim 10 wherein said member capture opening is U-shaped with ridges located about said member capture opening so as to prevent splaying of said saddle.

12. The anchor assembly of claim 10 wherein a peripheral wall of said saddle is flat.

13. The anchor assembly of claim 10 wherein said saddle includes reinforcing ridges.

14. The anchor assembly of claim 10 wherein said saddle has a peripheral wall which has an increasing thickness in the direction of where said member capture opening is provided through said peripheral wall.

15. The anchor assembly of claim 10 wherein:

said longitudinal bore is cylindrical with a screw thread and said fastener is a set screw which is cylindrical and includes a set screw thread that mates with the screw thread of the longitudinal bore; and

said saddle has a peripheral wall which is thicker where said member capture opening passes through said peripheral wall.

16. The anchor assembly of claim 10 wherein said member receiving opening is cylindrical with a screw thread and said fastener is a set screw which is cylindrical and includes a set screw thread that mates with the screw thread of the member receiving opening; and said saddle is thicker where said member receiving opening is provided through said end of said saddle.

17. The anchor assembly of claim 10 wherein said saddle has a roof-shaped peripheral wall.

18. An anchor assembly comprising:

an anchor body;

an anchor head including a first arm and a second arm extending substantially parallel to one another and away from the anchor body, the first arm and the second arm separated by a gap;

a shaft connected to the first arm and the second arm across the gap;

a saddle having a longitudinal bore, a transverse bore which intersects the longitudinal bore, and a member capture opening;

said transverse bore of said saddle being mounted about said shaft;

said saddle including a peripheral wall and an end located distally from said anchor;

said saddle including a member capture opening that is provided through said peripheral wall and opens to said distal end; wherein the member capture opening is adapted to receive a member, and wherein the member capture opening intersects the longitudinal bore;

a set screw received by said saddle in said longitudinal bore and adapted to lock the member in said saddle; and

said saddle including reinforced walls that prevent said saddle splaying when said set screw locks the member in said saddle.

19. The anchor assembly of claim 18 wherein said member capture opening is U-shaped with ridges located about said member capture opening so as to prevent splaying of said saddle.

20. The anchor assembly of claim 18 wherein said peripheral wall is flat.

21. The anchor assembly of claim 18 wherein said saddle includes reinforcing ridges.

22. The anchor assembly of claim 18 wherein said peripheral wall has an increasing thickness in the direction of where said member capture opening is provided through said peripheral wall.

23. The anchor assembly of claim 18 wherein said longitudinal bore is cylindrical with a screw thread and said set screw is cylindrical and includes a set screw thread that mates of the longitudinal bore; and said peripheral wall is thicker where said member capture opening is provided through said peripheral wall.

24. The anchor assembly of claim 18 wherein said peripheral wall is roof shaped.

25. An anchor assembly comprising:

an anchor body;

an anchor head including a first arm and a second arm extending substantially parallel to one another and away from the anchor body, the first arm and the second arm separated by a gap;

a saddle having a longitudinal bore, a transverse bore which intersects the longitudinal bore, and a slot adapted to receive a member wherein the slot bisects a proximal end to the saddle into a first section and a second section;

a shaft connected to the first arm and the second arm across the gap wherein said transverse bore of said saddle is mounted about said shaft such that the saddle can move relative to the anchor head;

a fastener received in said longitudinal bore of said saddle and adapted to lock the member in said slot of said saddle; and

wherein said first section and second section are roof-shaped to prevent splaying apart of the first section and second section when said fastener locks the member in said slot of saddle.

26. The anchor assembly of claim 25 , wherein the anchor body and anchor head are formed in one piece.

27. The anchor assembly of claim 25 , wherein the first section and second section are reinforced to prevent splaying apart of the first section and second section when said fastener locks the member in said slot of said saddle.

28. The anchor assembly of claim 25 , wherein said fastener is a set screw and wherein the longitudinal bore is threaded at the proximal end of the saddle to receive said set screw.

29. The anchor assembly of claim 25 , further comprising a saddle-mounting element mounted over said shaft wherein said transverse bore of said saddle is mounted about said saddle-mounting element mounted about said shaft such that the saddle can move relative to the anchor head.

30. The anchor assembly of claim 25 , further comprising a ball-shaped element mounted over said shaft wherein said transverse bore of said saddle is mounted about said ball-shaped element mounted about said shaft such that the saddle can move relative to the anchor head.