Rod reduction device and method of use

Patent metadata

Field	Value
Publication number	US-8961523-B2
Application number	US-77773007-A
Country	US
Kind code	B2
Filing date	Jul 13, 2007
Priority date	Jul 13, 2007
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

Provided is a novel rod reducing device including a screw jack mechanism that is moveably engaged with an elongated grasping fork assembly, the screw jack mechanism having an elongated threaded portion, the elongated threaded portion being connected at its most distal end to a rod contact member, which is positioned in sliding circumferential contact with each of the two opposing elongated grasping members and the most proximal end of the elongated threaded portion terminating in a controlling member, which can be activated in a measured and controlled manner. A method of using the device is also provided.

First claim

What is claimed is:

1. A rod reducing device, comprising:
a screw jack mechanism having an elongated threaded shaft terminating at a first proximal end with a controlling member and having at an opposite distal end a rod contact member; and
an elongated grasping fork assembly having opposing first and second elongated grasping members, the first and second elongated grasping members pivotally coupled to a fork assembly body, the fork assembly body having a longitudinal axis, and each of said opposing first and second elongated grasping members having a screw grasping element at an opposite distal end, said elongated threaded shaft of said screw jack mechanism being threadably engaged along the longitudinal axis of said fork assembly body, wherein said rod contact member defines respective through passages configured for slidable passage of said opposing first and second elongated grasping members, slidable movement of the rod contact member along the first and second elongated grasping members exerts a compressive force upon said opposing first and second elongated grasping members, thereby causing pivotal movement of said opposing first and second elongated grasping members with respect to one another.

2. The device of claim 1 , wherein each of said elongated grasping members includes a cam surface at proximal ends of said elongated grasping members that corresponds to the shape of the through passages of the rod contact member, such that movement of said rod contact member over said cam surfaces is capable of effecting movement of said screw grasping elements of said fork assembly toward each other.

3. The device of claim 2 , wherein movement of said grasping elements toward each other grasps and holds the head of a screw therebetween.

4. The device of claim 3 , wherein said fork assembly body further comprises at least one compression slot overlaid by a corresponding accessory connection tab.

5. The device of claim 4 , wherein said at least one compression slot is a pair of opposing compression slots.

6. The device of claim 5 , further including an alignment tube having a through lumen aligned along a longitudinal axis of the alignment tube, said through lumen being sized and configured to permit passage of said device through said through lumen.

7. The device of claim 6 , wherein said accessory connection tabs are configured to make contact with said alignment tube to facilitate a positive connection therebetween.

8. The device of claim 5 , wherein said accessory connection tabs are configured to provide positive engagement resistance with other instruments.

9. The device of claim 1 , further including a tool having an engagement end, said tool being configured to be capable of transferring applied torque to said device through contact of said tool engagement end to said controlling member of said screw jack mechanism of said device.

10. The rod reducing device of claim 1 , wherein a first pivot point is different from a second pivot point.

11. The device of claim 1 , wherein the first and second elongated grasping members are pivotally coupled to the fork assembly body about a first pivot and a second pivot, respectively.

12. The device of claim 11 , wherein the fork assembly body defines a first through hole dimensioned to receive a first pivot pin configured to pivotally couple the first elongated grasping member to the fork assembly body about the first pivot.

13. The device of claim 12 , wherein the fork assembly body further defines a second through hole dimensioned to receive a second pivot pin configured to pivotally couple the second elongated grasping member to the fork assembly body about the second pivot.

14. A method of reducing a rod into a rod receiving recess in a head of a bone screw, the method comprising:
providing a rod reducing device comprising:
a screw jack mechanism having an elongated threaded shaft terminating at a first proximal end with a controlling member and having at an opposite distal end a rod contact member; and
an elongated grasping fork assembly having opposing first and second elongated grasping members, the first and second elongated grasping members pivotally coupled to a fork assembly body, the fork assembly body having a longitudinal axis, and each of the first and second elongated grasping members having a screw grasping element at an opposite distal end, said elongated threaded shaft of said screw jack mechanism being threadably engaged along the longitudinal axis of the fork assembly body, wherein said rod contact member defines respective through passages configured for slidable passage of said opposing first and second elongated grasping members, slidable movement of the rod contact member along the first and second elongated grasping members exerts a compressive force upon said opposing first and second elongated grasping members, thereby causing pivotal movement of said opposing first and second elongated grasping members with respect to one another;

providing at least one bone screw and at least one surgical rod;
implanting said at least one bone screw into a bone of a subject;
positioning said at least one surgical rod in said device and positioning said device on said at least one bone screw; and
activating said device to effect grasping of said at least one bone screw and movement of said at least one surgical rod into position in said at least one bone screw.

15. The method of claim 14 , wherein a first pivot point is different from a second pivot point.

16. A kit for reducing a rod into a receiving recess of a bone screw, the kit comprising:
at least one of a rod reducing device comprising:
a screw jack mechanism having an elongated threaded shaft terminating at a first proximal end with a controlling member and having at an opposite distal end a rod contact member; and
an elongated grasping fork assembly having opposing first and second elongated grasping members, the first and second elongated rasping members pivotally coupled to a fork assembly body, the fork assembly body having a longitudinal axis, and each of the first and second elongated grasping members having a screw grasping element at an opposite distal end, said elongated threaded shaft of said screw jack mechanism being threadably engaged along the longitudinal axis of the fork assembly body, wherein said rod contact member defines respective through passages configured for slidable passage of said opposing first and second elongated grasping members, slidable movement of the rod contact member along the first and second elongated grasping members exerts a compressive force upon said opposing first and second elongated grasping members, thereby causing pivotal movement of said opposing first and second elongated grasping members with respect to one another.

17. The kit of claim 16 , further comprising at least one of the members selected from the group consisting of at least one bone screw, at least one surgical rod, at least one other orthopedic tool or device.

18. The kit of claim 17 , wherein said at least one other orthopedic tool or device is selected from the group consisting of a tightening or loosening tool, an alignment tube, and a locking device.

19. A rod reducing device, comprising:
a screw jack mechanism having an elongated threaded shaft terminating at a first proximal end with a controlling member and having at an opposite distal end a rod contact member; and
an elongated grasping fork assembly having opposing first and second elongated grasping members, the first and second elongated grasping membe

Assignees

• Barrus Michael
• Jones Scott A
• K2M Inc

Inventors

• Barrus Michael
• Jones Scott A

Classifications

• A61B17/7086 Primary

  Rod reducers, i.e. devices providing a mechanical advantage to allow a user to force a rod into or onto an anchor head other than by means of a rod-to-bone anchor locking element; rod removers · CPC title

• A61B17/7001

  Screws or hooks combined with longitudinal elements which do not contact vertebrae (A61B17/7058 takes precedence) · CPC title

• A61B17/88

  Osteosynthesis instruments;} Methods or means for implanting or extracting internal {or external} fixation devices {(A61B17/7074 takes precedence) · CPC title

• A61B17/8872

  Instruments for putting said fixation devices against or away from the bone (A61B17/7074, A61B17/808 take precedence) · CPC title

• A61B17/8875

  Screwdrivers, spanners or wrenches · CPC title