Systems and methods for spinal fixation

• US 20100036443A1
• Filed: 08/11/2009
• Published: 02/11/2010
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Alphatec Spine Incorporated (Alphatec Holdings Incorporated)
• Original Assignee: Alphatec Spine Incorporated (Alphatec Holdings Incorporated)
• Inventors: Hutton, Clark, Smith, Ketchen
• Granted Patent: US 8,394,109 B2
• Time in Patent Office: Days
• US Class Current: 606/86.R
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7077 for moving bone anchors attached to vertebrae, thereby displacing the vertebrae
• CPC Class Codes: A61B 17/708 with tubular extensions coaxially mounted on the bone anchors
• CPC Class Codes: A61B 17/7082 for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws driving other bone screws A61B17/8875
• CPC Class Codes: A61B 17/7083 Tools for guidance or insertion of tethers, rod-to-anchor connectors, rod-to-rod connectors, or longitudinal elements
• CPC Class Codes: A61B 17/7085 for insertion of a longitudinal element down one or more hollow screw or hook extensions, i.e. at least a part of the element within an extension has a component of movement parallel to the extension's axis
• 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
• CPC Class Codes: A61B 17/7091 for applying, tightening or removing longitudinal element-to-bone anchor locking elements, e.g. caps, set screws, nuts or wedges
• CPC Class Codes: A61B 17/8861 Apparatus for manipulating flexible wires or straps devices for inserting Kirschner wires A61B17/1697

Abstract

A spinal stabilization system, method, and a surgical kit having a surgical extender apparatus for implanting a surgical screw are disclosed. The extender includes a housing having a distal end and a proximal end, a hollow interior passageway disposed between the distal end and the proximal end, a channel disposed along an exterior surface of the housing at least partially between the distal end and the proximal end and configured to at least partially expose the hollow interior passageway, an interior locking mechanism disposed on an interior surface of the housing and substantially adjacent the proximal end, wherein the interior locking mechanism is configured to allow attachment of at least one surgical tool, and at least one flexible member disposed substantially adjacent the distal end. The housing is configured to accommodate placement of a surgical screw implant. The surgical screw implant is secured to the housing using a mating feature in the surgical screw implant. The at least one flexible member is configured to retain the surgical screw implant. The mating feature is configured to control axial movement of the surgical screw implant.

Claims

1. A distraction/compression tool for use with a screw extender system having at least two hollow screw extender housings configured to be coupled to respective screw assemblies implanted into vertebrae, the tool comprising:

a housing having

a first screw extender holding portion;

a second screw extender holding portion pivotally coupled to the first screw extender holding portion;

each screw extender holding portion includes a base configured to hold a screw extender housing;

a multi-directional threading mechanism configured to secure bases of the screw extender holding portion;

wherein rotation of the threading mechanism in one direction causes distraction of the screw extender housings coupled to the bases and rotation of the threading mechanism in another direction causes compression of the screw extender housings.

2. The distraction/compression tool according to claim 1, wherein each base further includes a respective base threading mechanism configured to interact with the multi-directional threading mechanism.

3. The distraction/compression tool according to claim 1, wherein the multi-directional threading mechanism includes at least one portion having right-handed directional threading and at least another portion having left-handed directional threading.

4. The distraction/compression tool according to claim 1, further comprising an exchangeable fulcrum handle configured to pivotally couple the holding portions at their respective top parts.

5. The distraction/compression tool according to claim 1, wherein the housing further comprises at least one access port for accessing screw extender housings coupled to the bases.

6. The distraction/compression tool according to claim 1, wherein plane of rotation of the multi-directional threading mechanism is configured to be substantially perpendicular to the plane of the screw extender housings coupled to the bases.

7. A method for compressing/distracting screw extender system using a distraction/compression tool, wherein the screw extender system includes at least two hollow screw extender housings configured to be coupled to respective screw assemblies implanted into vertebrae, the tool having

a housing having

a first screw extender holding portion;

a second screw extender holding portion pivotally coupled to the first screw extender holding portion;

each screw extender holding portion includes a base configured to hold a screw extender housing;

a multi-directional threading mechanism configured to secure bases of the screw extender holding portion;

wherein rotation of the threading mechanism in one direction causes distraction of the screw extender housings coupled to the bases and rotation of the threading mechanism in another direction causes compression of the screw extender housings;

the method comprising;

rotating the threading mechanism to compress/distract screw extender housings.

8. A rod inserter tool for use with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae, the tool comprising:

a handle coupled to a curved shaft at a proximal end of the curved shaft;

the shaft includes

a static shaft portion configured to be permanently coupled to the handle;

a sliding shaft portion configured to be slidably coupled inside the handle and further configured to slide along the static shaft portion;

a rod holding mechanism formed by the static shaft portion and a sliding shaft portion and configured to be disposed at a distal end of the curved shaft;

wherein by translating the sliding shaft portion along the static shaft portion toward the distal end of the shaft, the rod holding mechanism is configured to secure a rod.

9. The rod inserter tool according to claim 8, wherein the handle includes a threading mechanism configured to control translational movement of the sliding shaft portion.

10. The rod inserter tool according to claim 9, wherein the handle includes a control knob coupled to the threading mechanism, wherein rotation of the control knob in one direction is configured to translate the sliding shaft portion toward the distal end of the shaft and secure the rod in the rod holding mechanism, and rotation of the control knob in another direction is configured to translate the sliding shaft portion away from the distal end of the shaft and release the rod from the rod holding mechanism.

11. The rod inserter tool according to claim 8, wherein the rod holding mechanism includes at least one mating feature disposed on at least one of the static shaft portion and the sliding shaft portion for mating with at least one mating feature on the rod.

12. The rod inserter tool according to claim 8, wherein the rod holding mechanism is configured to hold the rod at a predetermined angle with respect to the shaft.

13. The rod inserter tool according to claim 8, wherein the static shaft portion is configured to include a groove and the sliding shaft portion is configured to include a corresponding protrusion configured to translate inside the groove of the static shaft portion to prevent excessive translation of the sliding shaft portion.

14. The rod inserter tool according to claim 8, wherein the sliding shaft portion is configured to slide inside the static shaft portion.

15. The rod inserter tool according to claim 14, wherein the rod holding mechanism includes a static lip portion coupled to the static shaft portion and a pivoting lip portion coupled to the sliding shaft portion, wherein translational movement of the sliding shaft portion is configured to rotate the pivoting lip portion with respect to the static lip portion.

16. The rod inserter tool according to claim 15, wherein at least one of the static lip portion and the pivoting lip portion includes at least one mating feature configured to interact with at least one corresponding mating feature disposed on the rod to further secure the rod in the rod holding mechanism.

17. The rod inserter tool according to claim 8, wherein the rod inserter tool is configured to insert the rod through the screw extender housing and toward the corresponding screw assembly.

18. A method of inserting a rod using a rod inserter tool in combination with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae, wherein the tool includes

a handle coupled to a curved shaft at a proximal end of the curved shaft;

the shaft includes

a static shaft portion configured to be permanently coupled to the handle;

a sliding shaft portion configured to be slidably coupled inside the handle and further configured to slide along the static shaft portion;

a rod holding mechanism formed by the static shaft portion and a sliding shaft portion and configured to be disposed at a distal end of the curved shaft;

wherein by translating the sliding shaft portion along the static shaft portion toward the distal end of the shaft, the rod holding mechanism is configured to secure a rod;

the method comprising;

securing the rod in the rod holding mechanism;

advancing the secured rod using the rod inserter tool through the screw extender housing and toward the corresponding screw assembly.

19. A re-attachment guide tool for re-attaching a hollow screw extender housing, having at least one open channel disposed in a wall of the screw extender housing, to a screw assembly implanted into a vertebrae, the tool comprising:

at least one guide shaft configured to be coupled to a screw assembly;

a main assembly having

a handle coupled to a flat shaft at a proximal end of the flat shaft;

a hollow housing coupled to the flat shaft at a distal end of the flat shaft and configured to accommodate insertion of the screw extender housing; and

a hollow interior disposed inside the handle and the flat shaft and configured to accommodate insertion of the at least one guide shaft;

the flat shaft is configured to have a predetermined thickness that allows coupling of the screw extender housing using the at least one open channel in the screw extender housing.

20. The re-attachment guide tool according to claim 19, further comprising a knob configured to secure the main assembly to the at least one guide shaft upon attachment of the shaft to the screw assembly and placement of the main assembly over the at least one guide shaft using the hollow interior of the main assembly.

21. The re-attachment guide tool according to claim 20, wherein during re-attachment of the screw extender housing to the screw assembly, the main assembly and the at least one guide shaft are configured to be secured to the screw assembly.

22. The re-attachment guide tool according to claim 21, wherein the at least one guide shaft includes a distal end configured to be screwed into the screw assembly.

23. The re-attachment guide tool according to claim 21, wherein the at least one guide shaft includes a distal end configured to interact with a setscrew disposed in the screw assembly.

24. The re-attachment guide tool according to claim 19, wherein upon coupling of the screw extender housing to the flat shaft, the screw extender housing is configured to be translated along the flat shaft through the hollow housing and toward the screw assembly for re-attachment of the screw extender housing to the screw assembly;

wherein the flat shaft and the hollow housing are configured to be secured to the screw assembly to allow proper re-attachment of the screw extender housing.

25. A method for re-attachment of a hollow screw extender housing to a screw assembly implanted in to a vertebrae using a re-attachment guide tool, wherein the hollow screw extender housing includes at least one open channel disposed in a wall of the screw extender housing, wherein the tool includes

at least one guide shaft configured to be coupled to a screw assembly;

a main assembly having

a handle coupled to a flat shaft at a proximal end of the flat shaft;

a hollow housing coupled to the flat shaft at a distal end of the flat shaft and configured to accommodate insertion of the screw extender housing; and

a hollow interior disposed inside the handle and the flat shaft and configured to accommodate insertion of the at least one guide shaft;

the flat shaft is configured to have a predetermined thickness that allows coupling of the screw extender housing using the at least one open channel in the screw extender housing;

the method comprising;

coupling the at least one guide shaft to the screw assembly;

placing the main assembly over the at least one guide shaft;

securing the main assembly to the screw assembly;

coupling the screw extender housing to the flat shaft of the main assembly;

translating the screw extender housing toward the distal end of the flat shaft; and

,

re-attaching the screw extender housing to the screw assembly.

26. A rod reducer tool for use with a screw extender housing secured to a screw assembly implanted into a vertebrae, the tool comprising:

a hollow shaft having a proximal and a distal end and configured to accommodate insertion of the screw extender housing;

a rotating handle coupled to the hollow shaft at the proximal end of the hollow shaft;

a first threading mechanism disposed inside the handle;

a second threading mechanism coupled to the handle and disposed inside the hollow shaft for coupling to the screw extender housing;

wherein the first threading mechanism is configured to allow independent rotation of the handle with respect to the hollow shaft;

wherein rotation of the handle is configured to translate the hollow shaft along the screw extender housing that has been inserted into the hollow shaft through interaction of the second threading mechanism with a threading mechanism disposed on the screw extender housing.

27. The rod reducer tool according to claim 26, wherein the translation of the hollow shaft along the screw extender housing is configured to secure a rod to the screw assembly.

28. The rod reducer tool according to claim 26, further comprising a collar disposed between the handle and the hollow shaft, wherein the collar includes a third threading mechanism configured to allow independent rotation of the handle and the collar.

29. A method for reducing a rod using a rod reducer tool used in connection with a screw extender housing secured to a screw assembly implanted into a vertebrae, the tool including

a hollow shaft having a proximal and a distal end and configured to accommodate insertion of the screw extender housing;

a rotating handle coupled to the hollow shaft at the proximal end of the hollow shaft;

a first threading mechanism disposed inside the handle;

a second threading mechanism coupled to the handle and disposed inside the hollow shaft for coupling to the screw extender housing;

wherein the first threading mechanism is configured to allow independent rotation of the handle with respect to the hollow shaft;

wherein rotation of the handle is configured to translate the hollow shaft along the screw extender housing that has been inserted into the hollow shaft through interaction of the second threading mechanism with a threading mechanism disposed on the screw extender housing;

the method comprising;

inserting the screw extender housing inside the hollow shaft;

translating the rod reducer tool along the screw extender housing toward the screw assembly;

rotating the rotating handle to advance the rod reducer tool toward the screw assembly, thereby reducing the rod.

30. A screw extender removal tool for removing a screw extender housing having flexible portions disposed at a distal end of the screw extender housing, wherein the screw extender housing is coupled to a screw assembly, the tool comprising:

an external shaft having a proximal end and a distal end, wherein a plurality of protrusions are disposed on an external surface at the distal end of the external shaft;

the external shaft having an internal shaft disposed in a hollow interior of the external shaft;

a handle coupled to the proximal end of the shaft, wherein the handle includes a spring-loaded mechanism pivotally coupled to the internal shaft;

wherein upon actuation of the spring-loaded mechanism, the internal shaft is translated in the hollow interior of the external shaft to extend beyond the distal end of the external shaft;

wherein the external shaft is configured to be

inserted into the screw extender housing coupled to the screw assembly;

using the handle, rotated to push apart the flexible portions of the screw extender housing; and

upon actuation of the spring loaded mechanism, further configured to extend the internal shaft beyond the distal end of the external shaft in order to remove the screw extender housing from the screw assembly.

31. The screw extender remover tool according to claim 30, further comprising a stopper mechanism disposed on the external surface of the external shaft and configured to prevent over-extension of the external shaft when the external shaft is placed inside the screw extender housing.

32. A method for removing a screw extender housing from a screw assembly using a screw extender removal tool, wherein the screw extender housing includes flexible portions disposed at a distal end of the screw extender housing and the screw extender housing is coupled to a screw assembly, the tool including

an external shaft having a proximal end and a distal end, wherein a plurality of protrusions are disposed on an external surface at the distal end of the external shaft;

the external shaft having an internal shaft disposed in a hollow interior of the external shaft;

a handle coupled to the proximal end of the shaft, wherein the handle includes a spring-loaded mechanism pivotally coupled to the internal shaft;

wherein upon actuation of the spring-loaded mechanism, the internal shaft is translated in the hollow interior of the external shaft to extend beyond the distal end of the external shaft;

the method comprising;

inserting the screw extender remover tool into the screw extender housing coupled to the screw assembly;

using the handle, rotating the screw extender remover tool to push apart the flexible portions of the screw extender housing using the plurality of protrusions; and

upon actuation of the spring loaded mechanism, extending the internal shaft beyond the distal end of the external shaft; and

,

removing the screw extender housing from the screw assembly.

33. A rod inserter tool for use with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae, the tool comprising:

a handle;

a main housing configured to include a rod holding mechanism adjacent to a distal end of the main housing for holding a rod, wherein the handle is coupled to the main housing adjacent to a proximal end of the main housing;

a secondary housing configured to be slidably disposed along the main housing and further configured to secure the rod to the distal end of the main housing;

a lateral housing configured to be slidably disposed along the main housing and further configured to change orientation of the rod upon being actuated by the handle.

34. The rod inserter tool according to claim 33, further comprising a switching mechanism coupled to the handle and configured to release the rod from the distal end of the main housing.

35. The rod inserter tool according to claim 34, wherein the rod is configured to be secured to the main housing in a first position that is substantially parallel to an axis of the main housing and upon actuation of the handle, the lateral housing is configured to change orientation of the rod into a second position that is substantially perpendicular to the axis of the main housing.

36. The rod inserter tool according to claim 35, wherein the switching mechanism is configured to release the rod from the distal end of the main housing, while the rod is disposed in the second position, by holding the secondary housing and the lateral housing so that the secondary and lateral housings do not contact the rod disposed at the distal end of the main housing.

37. A method of inserting a rod using a rod inserter tool in combination with a hollow screw extender housing configured to be coupled to a screw assembly implanted into vertebrae, wherein the tool includes

a handle;

a main housing configured to include a rod holding mechanism adjacent to a distal end of the main housing for holding a rod, wherein the handle is coupled to the main housing adjacent to a proximal end of the main housing;

a secondary housing configured to be slidably disposed along the main housing and further configured to secure the rod to the distal end of the main housing;

a lateral housing configured to be slidably disposed along the main housing and further configured to change orientation of the rod upon being actuated by the handle;

the method comprising the steps of;

coupling the rod to the distal end of the main housing of the rod inserter tool;

advancing the rod toward the screw assembly implanted into vertebrae along the screw extender housing coupled to the screw assembly;

securing to rod to the screw assembly; and

releasing the rod from the rod inserter tool.