Methods and apparatuses for vertebral body distraction and fusion employing a coaxial screw gear sleeve mechanism

• US 8,771,360 B2
• Filed: 08/22/2012
• Issued: 07/08/2014
• Est. Priority Date: 07/22/2009
• Status: Active Grant

• Current Assignee: SpineX Tec, LLC
• Original Assignee: SpineX Tec, LLC
• Inventors: Jimenez, Omar F., Powley, Nicholas Ransom, Fischer, Andrew G., Safris, Yefim
• Primary Examiner(s): Hammond, Ellen C
• Application Number:
  US13/591,463
• Publication Number:
  US 20120323329A1
• Time in Patent Office: 685 Days
• Field of Search: 623/17.16
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/7065 Devices with changeable shape, e.g. collapsible or having retractable arms to aid implantation; Tools therefor
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2017/681 Alignment, compression, or distraction mechanisms
• CPC Class Codes: A61F 2/385 also provided with condylar bearing surfaces
• CPC Class Codes: A61F 2/3868 with sliding tibial bearing
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/482 Electrical means
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30523 by means of meshing gear teeth
• CPC Class Codes: A61F 2002/30525 Worm gears
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30624 : Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/30639 : having rolling elements between both articulating surfaces
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30925 : etched
• CPC Class Codes: A61F 2002/3631 : with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/5041 : having bearing bushes between the rotating parts
• CPC Class Codes: A61F 2002/5069 : Ball bearings
• CPC Class Codes: A61F 2002/507 : Roller bearings
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2240/001 : Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61F 2310/00976 : Coating or prosthesis-covering structure made of proteins or of polypeptides, e.g. of bone morphogenic proteins BMP or of transforming growth factors TGF
• CPC Class Codes: A61F 2310/00982 : Coating made of collagen
• CPC Class Codes: A61F 2310/00988 : Coating made of fibrin
• CPC Class Codes: A61F 2310/00994 : Coating made of gelatin
• CPC Class Codes: F16H 2025/2046 : with gears arranged perpendicular to screw shaft axis, e.g. helical gears engaging tangentially the screw shaft
• CPC Class Codes: F16H 2025/2084 : Perpendicular arrangement of drive motor to screw axis
• CPC Class Codes: F16H 2025/209 : using worm gears
• CPC Class Codes: F16H 25/20 : Screw mechanisms with automatic reversal F16H25/12
• CPC Class Codes: F16H 25/2056 : Telescopic screws with at least three screw members in coaxial arrangement
• CPC Class Codes: F16H 25/2214 : with elements for guiding the circulating balls
• CPC Class Codes: H05K 999/99 : dummy group
• CPC Class Codes: Y10T 29/49 : Method of mechanical manufacture
• CPC Class Codes: Y10T 74/18608 : Single input split into two intermediate outputs that are subsequently superposed into a single output
• CPC Class Codes: Y10T 74/18672 : Plural screws in series [e.g., telescoping, etc.]
• CPC Class Codes: Y10T 74/19702 : Screw and nut
• CPC Class Codes: Y10T 74/19749 : Recirculating rolling elements

Abstract

Improved methods and apparatuses for vertebral body distraction and fusion in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to distract.

Claims

1. A distractible intervertebral body fusion device adapted for implantation into, and fusion of, an intervertebral disc space of a patient, comprising;

a first bearing surface;

a second bearing surface; and

at least one coaxial screw gear sleeve mechanism disposed between the first bearing surface and the second bearing surface, the coaxial screw gear sleeve mechanism including;

a threaded post projecting inwardly from one of the first bearing surface and the second bearing surface; and

a corresponding sleeve having a threaded interior surface surrounding and mating with the threaded post and a helically geared exterior surface;

wherein selective rotation of the sleeve causes an expansion of the first bearing surface relative to the second bearing surface due to a telescoping expansion resulting from the sleeve translating relative to one of the first bearing surface and the second bearing surface simultaneously with the threaded post translating relative to the sleeve,

such that the coaxial screw gear sleeve mechanism is adapted to support in-vivo loads between the first bearing surface and the second bearing surface to maintain a normal height of the disc space following implantation of the device into the intervertebral disc space and during a time fusion occurs between vertebral bodies of the intervertebral disc space of the patient.

2. The device of claim 1, wherein the geared exterior surface of the sleeve includes a plurality of gear teeth defined on a thread and the thread further includes an end portion comprising a bare thread portion not having gear teeth thereon.

3. The device of claim 2, further comprising a drive mechanism having a drive thread that interfaces with the geared exterior surface such that rotation of the drive mechanism causes rotation of the sleeve, wherein as the drive mechanism is rotated the gear teeth of the sleeve are sequentially contacted by the drive thread of the drive mechanism to rotate the sleeve relative to the threaded post to expand the first bearing surface and the second bearing surface relative to each other, and wherein the drive thread of the drive mechanism is unable to engage the bare thread portion such that as the drive mechanism advances from the gear teeth to the bare thread portion the drive mechanism is unable to rotate the sleeve to further expand the first bearing surface and the second bearing surface relative to each other.

4. The device of claim 3, wherein a relative linear distance of a portion of the thread having gear teeth thereon and the end portion comprising the bare thread portion is predetermined to provide a specific predetermined maximum amount of distraction between the first bearing surface and the second bearing surface.

5. The device of claim 2, wherein the end portion comprising the bare thread portion is adjacent a bottom end of the sleeve that is positioned adjacent one of the first bearing surface and the second bearing surface.

6. The device of claim 1, wherein an end of at least one of the first bearing surface and the second bearing surface is tapered in a direction transverse to a direction of the expansion.

7. The device of claim 1, wherein at least one of the first bearing surface and the second bearing surface is angled along a direction transverse to a direction of the expansion.

8. The device of claim 1, wherein the device includes a pair of coaxial screw gear sleeve mechanisms, and wherein each coaxial screw gear sleeve mechanism is independently rotatable.

9. The device of claim 8, further comprising a threaded member that engages the coaxial screw gear sleeve mechanisms to selectively rotate the sleeve of each coaxial screw gear sleeve mechanism, the threaded member including a first portion engaging a first of the coaxial screw gear sleeve mechanisms and a second portion engaging a second of the coaxial screw gear sleeve mechanisms, and wherein the first portion and the second portion are independently rotatable relative to each other.

10. The device of claim 1, wherein the first bearing surface is an outer surface of a first member and the second bearing surface is an outer surface of a second member, and wherein a junction where the threaded post meets an inner surface of the member corresponding to the one of the first bearing surface and the second bearing surface includes a chamfer.

11. The device of claim 1, wherein at least one of the first bearing surface and the second bearing surface includes an aperture extending through the bearing surface in a direction of the expansion.

12. A size-adjustable implant positionable between adjacent first and second vertebral bodies for fusion of the adjacent first and second vertebral bodies, the implant comprising:

a first member;

a second member;

a coaxial screw gear sleeve mechanism disposed between the first member and the second member, the coaxial screw gear sleeve mechanism including a sleeve having a helical thread with a plurality of gear teeth thereon; and

wherein selective rotation of the sleeve causes an expansion of the first member relative to the second member due to a telescoping expansion of the sleeve translating relative to one of the first member and the second member simultaneously with the other of the first member and the second member translating relative to the sleeve,

such that the coaxial screw gear sleeve mechanism is adapted to support in-vivo loads between the first member and the second member to maintain a normal height of the disc space following implantation of the device into the intervertebral disc space and during a time fusion occurs between vertebral bodies of the intervertebral disc space of the patient.

13. The implant of claim 12, wherein the thread further includes an end portion comprising a bare thread portion not having gear teeth thereon.

14. The device of claim 13, further comprising a drive mechanism having a drive thread that interfaces with the gear teeth of the sleeve such that rotation of the drive mechanism causes rotation of the sleeve, wherein as the drive mechanism is rotated the gear teeth of the sleeve are sequentially contacted by the drive thread of the drive mechanism to rotate the sleeve to expand the first member and the second member relative to each other, and wherein the drive thread of the drive mechanism is unable to engage the bare thread portion such that as the drive mechanism advances from the gear teeth to the bare thread portion the drive mechanism is unable to rotate the sleeve to further expand the first member and the second member relative to each other.

15. The device of claim 14, wherein a relative linear distance of a portion of the thread having gear teeth thereon and the end portion comprising the bare thread portion is predetermined to provide a specific predetermined maximum amount of distraction between the first member and the second member.

16. The device of claim 13, wherein the end portion comprising the bare thread portion is adjacent a bottom end of the sleeve that is positioned within one of the first member and the second member.

17. The device of claim 12, wherein an end of at least one of the first member and the second member is tapered in a direction transverse to a direction of the expansion.

18. The device of claim 12, wherein at least one of the first member and the second member is angled along a direction transverse to a direction of the expansion.

19. The device of claim 12, wherein the device includes a pair of coaxial screw gear sleeve mechanisms, and wherein each coaxial screw gear sleeve mechanism is independently rotatable.

20. The device of claim 19, further comprising a threaded member that engages the coaxial screw gear sleeve mechanisms to selectively rotate the sleeve of each coaxial screw gear sleeve mechanism, the threaded member including a first portion engaging a first of the coaxial screw gear sleeve mechanisms and a second portion engaging a second of the coaxial screw gear sleeve mechanisms, and wherein the first portion and the second portion are independently rotatable relative to each other.

21. The device of claim 12, wherein at least one of the first member and the second member includes an aperture extending through the member in a direction of the expansion.

22. A distractible intervertebral body fusion device adapted for implantation into, and fusion of, an intervertebral disc space of a patient, comprising;

a first bearing surface;

a second bearing surface; and

at least one coaxial screw gear sleeve mechanism disposed between the first bearing surface and the second bearing surface, the coaxial screw gear sleeve mechanism including;

a threaded post projecting inwardly from one of the first bearing surface and the second bearing surface; and

a corresponding sleeve having a threaded interior surface surrounding and mating with the threaded post and a helically geared exterior surface;

wherein selective rotation of the sleeve causes an expansion of the first bearing surface relative to the second bearing surface due to a telescoping expansion resulting from the sleeve translating relative to one of the first bearing surface and the second bearing surface simultaneously with the threaded post translating relative to the sleeve, such that the coaxial screw gear sleeve mechanism is adapted to support in-vivo loads between the first bearing surface and the second bearing surface to maintain a normal height of the disc space following implantation of the device into the intervertebral disc space and during a time fusion occurs between vertebral bodies of the intervertebral disc space of the patient,

wherein the threaded post is unitarily formed with the one of the first bearing surface and the second bearing surface.