Surgical plate with pawl and process for repair of a broken bone

• US 6,361,537 B1
• Filed: 05/18/2001
• Issued: 03/26/2002
• Est. Priority Date: 05/18/2001
• Status: Expired due to Fees

• Current Assignee: Cinci M. Anderson
• Original Assignee: Cinci M. Anderson
• Inventors: Anderson, Cinci M.
• Primary Examiner(s): Smith, Jeffrey A.
• Application Number:
  US09/860,406
• Time in Patent Office: 312 Days
• Field of Search: 606/69, 606/70, 606/71, 606/60
• US Class Current: 606/86.00B
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• CPC Class Codes: A61B 17/8047 wherein the additional element surrounds the screw head in the plate hole A61B17/8052 takes precedence
• 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 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 17/8605 Heads, i.e. proximal ends projecting from bone
• CPC Class Codes: A61B 2090/034 abutting on parts of the device itself

Abstract

A surgical plate and process for preventing screw backout of repaired bones. At least one pawl is provided on a surgical plate adjacent to a screw hole. A screw having a ratchet wheel is inserted through the hole and screwed into the bone. The pawl engages the ratchet wheel to prevent rotational movement of the screw to prevent the screw from backing out. In a preferred embodiment, a pawl plate comprising a base portion is rigidly connected to the surgical plate and a torsion bar is pivotally connected to the base portion. The pawl is positioned at the end of the torsion bar. In the preferred embodiments, several of these special screw holes with pawls, and several screws (each with a ratchet wheel) are used in bone repair.

Claims

1. A bone repair device for preventing screw backout of a repaired bone, said device comprising:

A) a surgical plate defining at least one hole,

B) at least one pawl connected to said surgical plate and positioned adjacent to said at least one hole,

C) at least one screw inserted through said at least one hole and for being screwed into said repaired bone, wherein said at least one screw comprises a ratchet wheel,

wherein said at least one pawl engages said ratchet wheel to prevent rotational movement of said at least one screw to prevent said at least one screw from backing out of said bone.

2. The bone repair device as in claim 1, wherein said at least one screw is a right hand screw and said pawl prevents rotational movement of said at least one screw in the counterclockwise direction.

3. The bone repair device as in claim 1, wherein said at least one screw is a left hand screw and said pawl prevents rotational movement of said at least one screw in the clockwise direction.

4. The bone repair device as in claim 1, wherein said at least one hole is a plurality of holes, wherein said at least one pawl is a plurality of pawls, wherein said at least one screw is a plurality of screws.

5. The bone repair device as in claim 1, further comprising a pawl plate, wherein said pawl plate comprises:

A) a base portion rigidly connected to said surgical plate, and

B) at least one torsion bar connected to said base portion, wherein said at least one pawl is connected to said at least one torsion bar.

6. The bone repair device as in claim 1, wherein said at least one screw is a hex screw.

7. The bone repair device as in claim 1, wherein said at least one screw comprises a bottom hemisphere portion.

8. The bone repair device as in claim 1, wherein the wall of said at least one hole comprises a plurality of dimples.

9. The bone repair device as in claim 1, further comprising a plurality of “

V”

shaped compression ridges.

10. The bone repair device as in claim 1, wherein said at least one screw is for being screwed into at least one bone hole, wherein said at least one bone hole is drilled utilizing a drill comprising:

A) a drill bushing defining a drill bushing hole aligned with said at least one hole of said surgical plate,

B) a drill bit inserted through said drill bushing hole,

C) a drill chuck for holding said drill bit, and

D) a spring positioned between said drill bushing and said drill chuck.

11. A bone repair device for preventing screw backout, comprising:

A) a surgical plate means defining at least one hole,

B) at least one pawl means connected to said surgical plate means and positioned adjacent to said at least one hole,

C) at least one screw means inserted through said at least one hole, wherein said at least one screw means comprises a ratchet wheel,

wherein said at least one pawl means engages said ratchet wheel to prevent rotational movement of said at least one screw means to prevent said at least one screw means from backing out.

12. The bone repair device as in claim 11, wherein said at least one screw means is a right hand screw and said pawl means prevents rotational movement of said at least one screw means in the counterclockwise direction.

13. The bone repair device as in claim 11, wherein said at least one screw means is a left hand screw and said pawl means prevents rotational movement of said at least one screw means in the clockwise direction.

14. The bone repair device as in claim 11, wherein said at least one hole is a plurality of holes, wherein said at least one pawl means is a plurality of pawls, wherein said at least one screw means is a plurality of screws.

15. The bone repair device as in claim 11, further comprising a pawl plate means, wherein said pawl plate means comprises:

A) a base portion means rigidly connected to said surgical plate means, and

B) at least one torsion bar means connected to said base portion means, wherein said at least one pawl means is connected to said at least one torsion bar means.

16. The bone repair device as in claim 11, wherein said at least one screw means is a hex screw.

17. The bone repair device as in claim 11, wherein said at least one screw means comprises a bottom hemisphere portion.

18. The bone repair device as in claim 11, wherein the wall of said at least one hole comprises a plurality of dimples.

19. The bone repair device as in claim 11, further comprising a plurality of “

V”

shaped compression ridges.

20. The bone repair device as in claim 11, wherein said at least one screw means is for being screwed into at least one bone hole, wherein said at least one bone hole is drilled utilizing a drill comprising:

A) a drill bushing means defining a drill bushing hole aligned with said at least one hole of said surgical plate means,

B) a drill bit means inserted through said drill bushing hole,

C) a drill chuck means for holding said drill bit means, and

D) a spring means positioned between said drill bushing means and said drill chuck means.

21. A process for repair of a broken bone defining two parts of said bone, comprising the steps of:

A) joining at least two parts of a broken bone together,

B) positioning a surgical plate to cover said at least two parts of said broken bone, said surgical plate having a plurality of holes, each of said plurality of holes having a pawl positioned adjacent to it, and

C) inserting a screw having a ratchet head into each of said plurality of holes and screwing each of said screw into said bone so that said pawl connects with said ratchet head to prevent said screw from backing out of said bone.