Orthopedic locking screw

Patent metadata

Field	Value
Publication number	US-12108972-B2
Application number	US-202117378002-A
Country	US
Kind code	B2
Filing date	Jul 16, 2021
Priority date	Dec 6, 2017
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

An orthopedic locking screw arranged in a bore of an orthopedic implant enables easy removal of a broken locking screw out of the implant. The orthopedic locking screw for a cooperation with a thread in the orthopedic implant comprises a longitudinally extending shaft. The shaft comprises a thread pattern section extending at least partially along the shaft. The thread pattern section comprises a first thread with a first direction, which is a functional thread configured for the cooperation with the thread in the orthopedic implant. The thread pattern section further comprises a second thread with a second direction opposite to the first direction of the first thread. The second thread is superimposed on the first thread and intersects the first thread. An orthopedic locking system comprises the orthopedic locking screw and the orthopedic implant. The locking screw is manufactured by applying the thread pattern section to the longitudinally extending shaft.

First claim

The invention claimed is:

1. An orthopedic locking screw comprising:
a shaft including a thread pattern section extending along at least part of the shaft,
the thread pattern section including a first thread oriented in a first direction and a second thread oriented in a second direction opposite the first direction, the first thread including a helically extending crest and the second thread including a plurality of rhombic shaped crests recessed relative to the helically extending crest,
wherein a minimum height of each rhombic shaped crest of the plurality of rhombic shaped crests is raised relative to a first surface of the shaft, and
wherein each rhombic shaped crest of the plurality of rhombic shaped crests includes a second surface at a first radius from a longitudinal axis of the shaft, the second surface having a perimeter defined in part by an edge extending across a width of the first thread, the edge being at an oblique angle relative to an alignment direction of the helically extending crest adjacent to the rhombic shaped crest.

2. The orthopedic locking screw of claim 1 , wherein the plurality of rhombic shaped crests together define a helical path along part of the shaft.

3. The orthopedic locking screw of claim 2 , wherein the plurality of rhombic shaped crests include at least a first rhombic shaped crest smaller than a second rhombic shaped crest, the first rhombic shaped crest being closer to a tip of the shaft than the second rhombic shaped crest.

4. The orthopedic locking screw of claim 1 , wherein the helically extending crest and each of the plurality of rhombic shaped crests have a first width measured in a direction perpendicular to a longitudinal axis of the first thread.

5. The orthopedic locking screw of claim 1 , wherein the thread pattern section includes a helically extending root adjacent to the helically extending crest, the helically extending root being separated from each of the plurality of rhombic shaped crests by a step.

6. The orthopedic locking screw of claim 5 , wherein the helically extending root does not overlap with the first thread or the second thread.

7. The orthopedic locking screw of claim 1 , further comprising a head abutting an end of the shaft, the head having an outer thread oriented in the same direction as the second thread.

8. A system comprising:
the orthopedic locking screw of claim 1 ; and
an orthopedic implant including a bore with a threaded surface,
wherein the first thread of the orthopedic locking screw is functionally engageable with the threaded surface of the bore.

9. An orthopedic locking screw comprising:
a shaft including a thread pattern section over at least part of the shaft,
the thread pattern section including a helical crest and a helical root, a first part of the helical crest defining a first thread in a first direction and a second part of the helical crest defining a second thread in a second direction opposite the first direction, the first part being separate from the second part,
wherein the helical crest has a first minimum height relative to the helical root at the first part and a second minimum height relative to the helical root at the second part, the first minimum height being greater than the second minimum height, and the second minimum height being greater than zero, and
wherein the second part includes a plurality of second subparts, each of the plurality of second subparts including a circumferentially planar surface, a first tapered surface and a second tapered surface, the circumferentially planar surface-extending from a leading edge to a trailing edge, the leading edge and the trailing edge both being at an oblique angle relative to a longitudinal axis of the helical crest, the first tapered surface being in between the first part of the helical crest and the leading edge along the longitudinal axis, and the second tapered surface being in between the trailing edge and the first part of the helical crest along the longitudinal axis.

10. The orthopedic locking screw of claim 9 , wherein the first part includes a plurality of first subparts, each of the plurality of first subparts being separated by one second subpart of the plurality of second subparts.

11. The orthopedic locking screw of claim 10 , wherein each of the plurality of second subparts has a rhombic shape and each of the plurality of first subparts has a non-rhombic shape.

12. The orthopedic locking screw of claim 10 , wherein a shape of the first tapered surface on a first side of a centerline of the helical crest is different from a shape of the second tapered surface on the first side.

13. The orthopedic locking screw of claim 9 , wherein the second thread defines a helical path in the second direction such that each of the plurality of second subparts is separated by the helical root.

14. A system comprising:
the orthopedic locking screw of claim 9 ; and
an orthopedic implant including a bore with a threaded surface,
wherein the first thread of the orthopedic locking screw is functionally engageable with the threaded surface of the bore.

15. An orthopedic locking screw comprising:
a shaft including a thread pattern section over at least part of the shaft,
the thread pattern section including a first thread in a first direction and a second thread in a second direction opposite the first direction, the second thread being entirely within the first thread such that the second thread is defined by a plurality of recessed portions in the first thread,
wherein the first thread includes a crest centered along a first central longitudinal axis of the first thread extending helically about the shaft,
wherein each of the plurality of recessed portions includes a first edge, a second edge and a surface therebetween, the first edge and the second edge being on opposite sides of the first central longitudinal axis of the first thread and the surface being at a substantially uniform distance from a second central longitudinal axis of the shaft from a leading edge of the surface to a trailing edge of the surface, and
wherein each of the plurality of recessed portions is asymmetrical about a plane substantially aligned with and passing through the first central longitudinal axis and the shaft.

16. The orthopedic locking screw of claim 15 , wherein each of the plurality of recessed portions has a first surface area on a first side of the first central longitudinal axis and a second surface area on a second side of the first central longitudinal axis, the first surface area being equal to the second surface area.

17. The orthopedic locking screw of claim 15 , wherein the first edge and the second edge are adjacent to a root of the thread pattern section.

18. The orthopedic locking screw of claim 15 , wherein each of the plurality of recessed portions extend a first maximum distance on a first side of the first central longitudinal axis and the first maximum distance on a second side of the first central longitudinal axis.

19. The orthopedic locking screw of claim 15 , wherein each of the plurality of recessed portions has a shape with an axis of symmetry passing therethrough, the axis of symmetry being at an angle relative to the plane.

20. A system comprising:
the orthopedic locking screw of claim 15 ; and
an orthopedic implant including a bore with a threaded surface,
wherein the first thread of the orthopedic locking screw is functionally engageable with the threaded surface of the bore.

Assignees

• Stryker European Operations Holdings Llc

Inventors

• Zander Nils
• Wieland Manfred

Classifications

• A61B2017/00526

  Methods of manufacturing · CPC title

• A61B17/8635

  Tips of screws · CPC title

• A61B17/725

  with locking pins or screws of special form · CPC title

• A61B17/863 Primary

  with thread interrupted or changing its form along shank, other than constant taper · CPC title

• A61B17/72 Primary

  Intramedullary devices, e.g. pins or nails · CPC title