Bone Screws and Bone Screw Systems

• US 20130030474A1
• Filed: 07/26/2012
• Published: 01/31/2013
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: Scott & White Healthcare (Baylor Scott & White Health LLC)
• Original Assignee: Scott & White Healthcare (Baylor Scott & White Health LLC)
• Inventors: Chaput, Christopher
• Granted Patent: US 10,022,171 B2
• Time in Patent Office: Days
• US Class Current: 606/305
• CPC Class Codes: A61B 17/7035 Screws or hooks, wherein a rod-clamping part and a bone-anchoring part can pivot relative to each other
• CPC Class Codes: A61B 17/7044 also having plates, staples or washers bearing on the vertebrae
• CPC Class Codes: A61B 17/7049 Connectors, not bearing on the vertebrae, for linking longitudinal elements together A61B17/7055, A61B17/7053, A61B17/7019 take precedence
• CPC Class Codes: A61B 17/7071 Implants for expanding or repairing the vertebral arch or wedged between laminae or pedicles; Tools therefor
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61B 2090/036 abutting on tissue or skin

Abstract

Bone screws, such as polyaxial bone screws, with dilations located between the screw head and the threaded portion of the screw, for use in preserving polyaxial functionality of the screw head and/or to which crosslinks may be coupled.

Claims

1. A bone screw comprising:

a shaft having an axis about which the shaft can rotate, and a shaft dimension along a line substantially perpendicular to and intersecting the axis, the shaft comprising a threaded portion that has a top;

a head fixed to the shaft and configured to be coupled to a cap, the head having a bottom; and

a dilation coupled to or integral with the shaft, the dilation having a dilation dimension along a line substantially perpendicular to and intersecting the axis and spaced apart from both the bottom of the head and from the top of the threaded portion, the dilation dimension being greater than the shaft dimension.

2. The bone screw of claim 1, further comprising:

a cap configured to be coupled to the head of the bone screw.

3. The bone screw of claim 2, where the cap and the head are configured to be polyaxially coupled to each other.

4. The bone screw of claim 1, where the dilation has a substantially-circular cross-section in a plane substantially perpendicular to the axis.

5. The bone screw of claim 4, where the dilation has a top, a bottom, a first outer perimeter in a first plane that is perpendicular to the axis and positioned between the top of the dilation and the dilation dimension, a second outer perimeter positioned in a second plane parallel to the First plane and intersecting the dilation dimension, and a third outer perimeter positioned in a third plane parallel to the first plane and positioned between the dilation dimension and the bottom of the dilation, the second outer perimeter being greater than the first outer perimeter and being greater than the third outer perimeter.

6. The bone screw of claim 5, further comprising a cap configured to be coupled to the head of the bone screw, the bone screw being configured such that the dilation docs not contact the cap when the cap is coupled to the head.

7. The bone screw of claim 4, where the dilation has a top, a bottom, a first outer perimeter in a first plane that is perpendicular to the axis and positioned between the top of the dilation and the dilation dimension, a second outer perimeter positioned in a second plane parallel to the first plane and intersecting the dilation dimension, and a third outer perimeter positioned in a third plane parallel to the first plane and positioned between the dilation dimension and the bottom of the dilation, the first outer perimeter defining a first area, the second outer perimeter defining a second area, and the third outer perimeter defining a third area, the second area being greater than the first area and being greater than the third area.

8. The bone screw of claim 1, where the dilation has a substantially-hexagonal cross-section in a plane substantially perpendicular to the axis.

9. The bone screw of claim 1, where the dilation has a substantially-elliptical cross-section in a plane substantially perpendicular to the axis.

10. The bone screw of claim 1, where the bone screw has an overall length that is between about 10 mm and about 80 mm.

11. The bone screw of claim 10, where the dilation dimension is 4 millimeters to 16 millimeters.

12. A bone anchoring system comprising:

a bone screw comprising;

a shaft having an axis about which the shaft can rotate, and a shaft dimension along a line substantially perpendicular to and intersecting the axis, the shaft comprising a threaded portion that has a top;

a head fixed to the shaft and configured to be coupled to a cap, the head having a bottom;

a dilation coupled to or integral with the shaft, the dilation having a dilation dimension along a line substantially perpendicular to and intersecting the axis and spaced apart from both the bottom of the head and from the top of the threaded portion, the dilation dimension being greater than the shaft dimension; and

a cap configured to be coupled to the head of the bone screw.

13. The system of claim 12, where the cap and the head are configured to be polyaxially coupled to each other.

14. The bone screw of claim 13, where the dilation has a top, a bottom, a first outer perimeter in a first plane that is perpendicular to the axis and positioned between the top of the dilation and the dilation dimension, a second outer perimeter positioned in a second plane parallel to the first plane and intersecting the dilation dimension, and a third outer perimeter positioned in a third plane parallel to the first plane and positioned between the dilation dimension and the bottom of the dilation, the second outer perimeter being greater than the first outer perimeter and being greater than the third outer perimeter.

15. The bone screw of claim 13, where the bone screw is configured such that the dilation does not contact the cap when the cap is coupled to the head.

16. The bone screw of claim 13, where the dilation has a top, a bottom, a first outer perimeter in a first plane that is perpendicular to the axis and positioned between the top of the dilation and the dilation dimension, a second outer perimeter positioned in a second plane parallel to the first plane and intersecting the dilation dimension, and a third outer perimeter positioned in a third plane parallel to the first plane and positioned between the dilation dimension and the bottom of the dilation, the first outer perimeter defining a first area, the second outer perimeter defining a second area, and the third outer perimeter defining a third area, the second area being greater than the first area and being greater than the third area.

17. The system of claim 12, further comprising a washer, where the washer and the dilation arc configured to be polyaxially coupled to each other.

18. The system of claim 17, where the washer further comprises a plurality of cleats.

19. The system of claim 12, further comprising a crosslink configured to be coupled to the dilation of the bone screw.

20. The system of claim 19, where the crosslink comprises a clamp, and the clamp and the dilation are configured to be polyaxially coupled to each other.

21-44. -44. (canceled)