SINGLE ACTION ANTI-TORQUE ROD REDUCER

• US 20120215266A1
• Filed: 02/22/2012
• Published: 08/23/2012
• Est. Priority Date: 02/22/2011
• Status: Active Grant

• Current Assignee: K2M, Inc (Stryker Corporation)
• Original Assignee: K2M, Inc (Stryker Corporation)
• Inventors: Jones, Scott
• Granted Patent: US 8,764,756 B2
• Time in Patent Office: Days
• US Class Current: 606/86.A
• CPC Class Codes: A61B 17/7086 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

Abstract

A rod reducing device includes an elongate member, a pair of jaw members, a sleeve having a cam pin, and an actuation lever. Translation of the cam pin along the inner surfaces of the jaw members pivotally moves the jaw members between a receiving position in which distal end portions of the respective jaw members are widened and an engaging position in which the distal end portions of the respective jaw members are move toward each other to engage the head of the bone screw. The actuation lever is movable between an open in which a distal end portion of the sleeve is disposed proximal of the distal end portions of the jaw members and a closed position in which the distal end portion of the sleeve is disposed distal of the distal end portions of the jaw members for reducing the connecting rod.

Claims

1. A rod reducing device for reducing a connecting rod into position with a head of a bone screw, the rod reducing device comprising:

an elongate member defining a lumen therethrough;

a pair of opposing jaw members pivotally associated with the elongate member;

a sleeve having a longitudinal passage therethrough, the sleeve slidably surrounding at least partially the elongate member and the pair of opposing jaw members, the sleeve including a cam pin configured to engage inner surfaces of the pair of opposing jaw members, translation of the cam pin along the inner surfaces of the pair of opposing jaw members pivotally moves the pair of opposing jaw members between a receiving position in which distal end portions of the respective pair of opposing jaw members are widened to receive the head of the bone screw therebetween and an engaging position in which the distal end portions of the respective pair of opposing jaw members are moved toward each other to engage the head of the bone screw therebetween; and

an actuation lever pivotably mounted on the elongate member, the actuation lever operatively coupled to the sleeve, the actuation lever movable between an open position in which a distal end portion of the sleeve is disposed proximal of the distal end portions of the pair of opposing jaw members in the receiving position, and a closed position in which the distal end portion of the sleeve is disposed distal of the distal end portions of the pair of opposing jaw members in the engaging position for reducing the connecting rod into position in the head of the bone screw.

2. The rod reducing device according to claim 1, wherein in the open position, the actuation lever is offset with respect to the longitudinal axis defined by the elongate member and in the closed position the actuation lever is aligned with the longitudinal axis.

3. The rod reducing device according to claim 1, further comprising a knob rotatable about the sleeve, wherein rotation of the knob axially adjusts a distance of travel of the sleeve by the actuation lever.

4. The rod reducing device according to claim 3, wherein the knob is rotatable between a first position adapted to reduce a first rod connector having a first diameter and a second position adapted to reduce a second rod connector having a second diameter.

5. The rod reducing device according to claim 1, further comprising a linkage member interconnecting the actuation lever with the sleeve.

6. The rod reducing device according to claim 1, wherein the pair of opposing jaw members is configured to securely grasp a head of the bone screw when the actuation lever is in the closed position.

7. The rod reducing device according to claim 6, wherein each of the pair of opposing jaw members includes a protrusion, and the elongate member defines a pair of sockets configured and dimensioned for pivotal engagement of the respective protrusions of the pair of opposing jaw members therein.

8. The rod reducing device according to claim 1, wherein the sleeve defines a pair of opposing slots dimensioned to receive the pair of opposing jaw members therethrough, respectively.

9. The rod reducing device according to claim 1, wherein the inner surfaces of the pair of opposing jaw members each include an inner camming surface extending radially inward from the inner surface, the cam pin engaging the respective inner camming surfaces when the actuation lever is in the open position, thereby urging the pair of opposing jaw members toward the receiving position.

10. The rod reducing device according to claim 9, wherein the inner camming surface is disposed at a proximal portion of the respective pair of opposing jaw members.

11. The rod reducing device according to claim 1, wherein each of the pair of opposing jaw members further includes an outer surface having an outer camming surface extending radially outward from the outer surface, the sleeve engaging the outer camming surfaces when the actuation lever is in the closed position, thereby urging the pair of opposing jaw members toward the engaging position.

12. The rod reducing device according to claim 11, wherein the outer camming surfaces are disposed at the respective distal end portions of the pair of opposing jaw members.

13. The rod reducing device according to claim 1, wherein the cam pin is fixed securely with the sleeve for a single body movement with the sleeve.

14. The rod reducing device according to claim 1, further comprising a biasing member to urge the sleeve to move proximally when the actuation lever is in the closed position.

15. The rod reducing device according to claim 1, wherein the cam pin conforms to the contour of the lumen of the elongate member to facilitate passage of a screw cap therethrough.

16. The rod reducing device according to claim 1, wherein the lumen of the elongate member is configured and dimensioned for passage of a bone screw locking cap and an instrument for tightening the locking cap into place with the bone screw.

17. The rod reducing device according to claim 1, wherein the distal end portion of the sleeve includes a connecting rod drive member configured and adapted to at least partially receive the connecting rod therein.