Surgical instrument and method

Patent metadata

Field	Value
Publication number	US-11026736-B2
Application number	US-201815899103-A
Country	US
Kind code	B2
Filing date	Feb 19, 2018
Priority date	Feb 19, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A surgical system includes a bone fastener having a head and a shaft. The head has a drive interface surface including elliptical edges. A surgical instrument includes an inner drive and an outer sleeve that is engageable with an outer surface of the head to dispose the inner drive and the outer sleeve with the head in a co-axial, capture orientation. The inner drive has a drive interface surface including a plurality of spaced apart lobes. Each lobe has an elliptical edge engageable with one of the elliptical edges of the drive interface surface of the head. Spinal constructs, implants and methods are disclosed.

First claim

What is claimed is:

1. A surgical system comprising:
a bone fastener including a head and a shaft extending from the head in co-axial alignment and configured for penetrating tissue, the head having a drive interface surface including a plurality of elliptical edges spaced apart about the interface surface; and
a surgical instrument including an inner drive and an outer sleeve, the inner drive including a shank, a drive interface extending from the shank and spaced apart arms disposed about the drive interface, the shank defining a longitudinal axis, the outer sleeve comprising a flange extending perpendicular to the longitudinal axis, the arms defining a collet that is expandable to receive the head, the shank comprising a first thread that mates with a second thread of the outer sleeve such that rotation of the inner drive relative to the outer sleeve translates the inner drive relative to the outer sleeve to move the collet between a first orientation in which the arms are spaced apart by a first distance and a second orientation in which the arms are spaced apart by an increased second distance, the flange engaging surfaces of the arms that extend perpendicular to the longitudinal axis when the collet is in the first orientation to prevent translation of the inner drive relative to the outer sleeve along the longitudinal axis in one direction, the drive interface surface including a plurality of spaced apart lobes, each lobe having an elliptical edge engageable with one of the elliptical edges of the drive interface surface of the head.

2. A surgical system as recited in claim 1 , wherein the interface surface of the head comprises a plurality of protrusions including the elliptical edges of the head circumferentially disposed about the interface surface of the head.

3. A surgical system as recited in claim 1 , wherein the interface surface of the head comprises a hexalobe socket having six spaced apart protrusions including the elliptical edges of the head.

4. A surgical system as recited in claim 1 , wherein the elliptical edges of the head are defined by an ellipse having a major axis of between about 2.0 mm and 2.3 mm and a minor axis of between about 1.00 mm and 1.3 mm.

5. A surgical system as recited in claim 1 , wherein the interface surface of the inner drive comprises a plurality of recesses disposed between the lobes and including the elliptical edges of the inner drive.

6. A surgical system as recited in claim 1 , wherein the lobes are circumferentially disposed about the interface surface of the inner drive and each lobe includes a leading elliptical edge, a tip edge and a trailing elliptical edge.

7. A surgical system as recited in claim 1 , wherein the interface surface of the inner drive comprises a hexalobe drive having six lobes with grooves, and the elliptical edges of the inner drive are disposed between the lobes.

8. A surgical system as recited in claim 1 , wherein the elliptical edges of the inner drive are defined by an ellipse having a major axis of between about 1.8 mm and 2.2 mm and a minor axis of between about 1.0 mm and 1.4 mm.

9. A surgical system as recited in claim 1 , wherein the lobes are configured to transmit and/or withstand a torque in a range of between about 18 Nm to 24 Nm.

10. A surgical system as recited in claim 1 , wherein the inner drive includes cannulation.

11. A surgical system as recited in claim 1 , wherein the shaft includes cannulation.

12. A surgical system as recited in claim 1 , wherein the outer sleeve includes an end that moves along the arms to move the collet between the orientation and the second orientation.

13. A surgical system as recited in claim 1 , wherein the arms each include an element engageable with an outer surface of the head.

14. A surgical system as recited in claim 1 , wherein the outer sleeve comprises a tissue depth stop.

15. A surgical system as recited in claim 1 , wherein the outer sleeve comprises a barrel having a proximal limit and a distal limit limiting axial translation of the inner drive relative to the outer sleeve.

16. A surgical system as recited in claim 1 , wherein the drive interface surface of the head includes a plurality of elliptical edges spaced apart about the drive interface surface of the head, the drive interface surface of the shaft including a plurality of spaced apart lobes, each lobe having an elliptical edge engageable with one of the elliptical edges of the drive interface surface of the head.

17. A surgical system comprising:
a bone fastener including a head and a shaft extending from the head, the head having a drive interface surface; and
a surgical instrument including a shaft and a sleeve, the shaft of the surgical instrument including a shank, a drive interface extending from the shank and spaced apart arms disposed about the drive interface, the shank defining a longitudinal axis, the arms defining a collet that is expandable to receive the head, the sleeve comprising a stop extending perpendicular to the longitudinal axis, the shaft comprising a first thread that mates with a second thread of the sleeve such that rotation of the shaft of the surgical instrument relative to the sleeve translates the shaft of the surgical instrument relative to the sleeve to move the collet between a first orientation in which the arms are spaced apart by a first distance and a second orientation in which the arms are spaced apart by an increased second distance, the stop engaging surfaces of the arms that extends perpendicular to the longitudinal axis when the collet is in the first orientation to prevent translation of the shaft relative to the sleeve along the longitudinal axis in one direction, the shaft of the surgical instrument having a drive interface configured to engage the drive interface surface of the head.

18. A surgical system comprising:
a bone fastener including a head and a shaft extending from the head, the head having a drive interface surface; and
a surgical instrument including a shaft and a sleeve, the shaft of the surgical instrument including a shank, a drive interface extending from the shank and spaced apart arms disposed about the drive interface, the shank defining a longitudinal axis, the sleeve including a first stop surface extending transverse to the longitudinal axis, the head including a threaded portion attachable with the sleeve, the arms defining a collet that is expandable to receive the head, the shaft comprising a first thread that mates with a second thread of the sleeve such that rotation of the shaft relative to the sleeve translates the shaft relative to the sleeve to move the collet between a first orientation in which the arms are spaced apart by a first distance and a second orientation in which the arms are spaced apart by an increased second distance, the first stop surface engaging second stop surface of the arms that extend transverse to the longitudinal axis when the collet is in the first orientation to prevent translation of the shaft relative to the sleeve along the longitudinal axis in one direction, the shaft having a drive interface configured to engage the drive interface surface of the head.

Assignees

• Warsaw Orthopedic Inc

Inventors

• Rohlfing Alexander J
• May Jason M
• Bobbitt Dustin

Classifications

• A61B17/8891 Primary

  at its periphery · CPC title

• A61B17/8877 Primary

  characterised by the cross-section of the driver bit · CPC title

• A61B17/861

  specially shaped for gripping driver · CPC title

• A61B17/888

  the driver bit acting on the central region of the screw head · CPC title

• A61B17/7082

  for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws · CPC title