Bone plate with interference fit screw

• US 20050131413A1
• Filed: 06/21/2004
• Published: 06/16/2005
• Est. Priority Date: 06/20/2003
• Status: Abandoned Application

• Current Assignee: Joel Gillard, Shawn W O'Driscoll
• Original Assignee: Joel Gillard, Shawn W O'Driscoll
• Inventors: Gillard, Joel, O'Driscoll, Shawn W.
• Application Number:
  US10/873,410
• Publication Number:
  US 20050131413A1
• Time in Patent Office: Days
• US Class Current: 606/286
• CPC Class Codes: A61B 17/8052 immobilised relative to screws by interlocking form of the heads and plate holes, e.g. conical or threaded
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone

Abstract

Systems, including apparatus and methods, for internal fixation of a fractured or otherwise compromised bone. These systems may include and/or make use of bone plates, locking screws, and/or kits, among others.

Claims

1. A system for fixing a discontinuity in a bone, comprising:

a bone plate, comprising;

(a) a body portion having a bone-facing surface; and

(b) at least one unthreaded aperture, defined by the body portion, for receiving a bone screw, the aperture including (i) a lip portion adjacent the bone-facing surface of the bone plate and configured to frictionally engage a circular groove of the bone screw, and (ii) an arcuate seating surface shaped to engage an arcuate head portion of the bone screw.

2. The system of claim 1, further comprising at least two unthreaded apertures, each aperture having a lip portion and an arcuate seating surface as described in claim 1.

3. The system of claim 1, wherein the aperture is configured to receive a locking bone screw or a non-locking bone screw.

4. The system of claim 3, wherein the lip portion further is configured to engage the locking screw at a fixed angle within the aperture.

5. The system of claim 3, wherein the lip portion and the seating surface further are configured to engage the non-locking bone screw at a variable angle within the aperture.

6. The system of claim 1, wherein the body portion further comprises:

a bridge portion for spanning the discontinuity in the bone; and

an anchor portion for affixing the bone plate to the bone.

7. The system of claim 6, wherein the unthreaded aperture is located in the anchor portion.

8. The system of claim 6, wherein the anchor portion further includes attachment structure configured to receive a wire that helps to affix the bone plate to the bone.

9. The bone plate of claim 1, wherein the bone plate is composed of a biocompatible material.

10. The system of claim 1, further comprising:

a bone screw, comprising;

(a) a shaft portion for engaging the bone; and

(b) a head portion having a circular groove for engaging an aperture in a bone plate, the narrowest diameter of the circular groove being smaller than the diameter of the bone screw to either side of the circular groove.

11. The system of claim 10, wherein the shaft portion and/or head portion includes threads that terminate at the circular groove.

12. The system of claim 11, wherein the head portion is tapered to form a frustoconical section.

13. The system of claim 11, wherein the head portion includes an arcuate seating surface for further engaging the aperture.

14. The system of claim 13, wherein the arcuate seating surface is shaped to form a spherical radius.

15. The system of claim 13, wherein the arcuate seating surface is shaped to be complementary to a seating surface of the aperture.

16. The system of claim 11, wherein the circular groove lies in a plane substantially perpendicular to a long axis of the screw.

17. The system of claim 16, wherein the threads have a constant thread pitch.

18. The system of claim 11, wherein the circular groove engages the aperture by compressing a lip portion of the aperture within the groove.

19. The system of claim 10, wherein the bone screw is composed of a biocompatible material.

20. A bone screw, comprising:

a shaft portion for engaging the bone; and

a head portion having a circular groove for engaging an aperture in a bone plate, the narrowest diameter of the circular groove being smaller than the diameter of the bone screw to either side of the circular groove.