Method and apparatus for spinal distraction and fusion

• US 7,608,077 B2
• Filed: 07/26/2005
• Issued: 10/27/2009
• Est. Priority Date: 02/16/2000
• Status: Expired due to Fees

• Current Assignee: Mis Ip Holdings LLC
• Original Assignee: TranS1 Incorporated (Baxano Surgical, Inc.)
• Inventors: Assell, Robert L., Cragg, Andrew H., Dickhudt, Eugene A.
• Primary Examiner(s): Philogene; Pedro
• Application Number:
  US11/189,943
• Publication Number:
  US 20050261695A1
• Time in Patent Office: 1,554 Days
• Field of Search: 606/61, 606/63, 606/65, 606/72, 606/73, 606/105, 606/90, 606/86.R, 606/246, 606/247, 433172-176, 623/16.11, 623/18.11
• US Class Current: 606/86.00R
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/7055 connected to sacrum, pelvis or skull
• CPC Class Codes: A61B 17/7061 for stabilising vertebrae or discs by improving the condition of their tissues, e.g. using implanted medication or fluid exchange intraosseous injection devices A61B17/3472
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/00557 inflatable A61B2017/22051 takes precedence
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61B 2017/2905 flexible
• CPC Class Codes: A61B 2017/320012 Brushes
• CPC Class Codes: A61B 2017/320733 with a flexible cutting or scraping element, e.g. with a whip-like distal filament member
• CPC Class Codes: A61B 2017/564 Methods for bone or joint treatment
• CPC Class Codes: A61F 2/30723 Plugs or restrictors for sealing a cement-receiving space tools for inserting plugs A61F2/4614; sealing collars for use during cementing A61B17/8808
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• CPC Class Codes: A61F 2/442 : Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• 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 2/4601 : for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4611 : of spinal prostheses
• 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 2002/30092 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30233 : Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• CPC Class Codes: A61F 2002/30563 : having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30784 : Plurality of holes
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30859 : having threaded portions of different pitches
• CPC Class Codes: A61F 2002/30879 : Ribs
• 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 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• 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

Abstract

The invention provides an implantable spinal distraction/fusion rod with varied thread pitch and diameters along different portions of its length that it is capable of distracting two or more vertebral bodies relative to each other and/or facilitating the procedure of fusing the vertebral bodies together from within the spine. The present invention also provides for methods of using the rod to distract and/or fuse two or more vertebral bodies from within the spine.

Claims

1. An axially-extending implantable rod for adjusting a distance between two adjacent vertebral bodies in a spine, said rod comprising:

an elongated body dimensioned for implantation along an axis extending from an access point on the anterior surface of the sacrum and for maintaining the distance between the two adjacent vertebral bodies;

a first section near a leading end of the rod that has a first threading for engaging with a first vertebral body, the first threading comprising a first major diameter and a first minor diameter;

a second section near a trailing end of the rod that has a second threading for engaging with a second vertebral body that is located inferiorly relative to the first vertebral body, the second threading comprising a second major diameter and a second minor diameter;

an intermediate section extending between the distal and proximal sections, the intermediate section being sized and configured for maintaining the distance between the two vertebral bodies;

a central lumen extending axially from the trailing end into the body; and

at least one transverse aperture extending through the wall of the intermediate section and in communication with the lumen;

wherein the first major diameter of the first threading is less than the second major diameter of the second threading;

wherein a first thread pitch in the first section is finer relative to a second thread pitch in the second section such that advancement of the first section distally into the first vertebral body by rotation causes an increase in distance between the first and second vertebral bodies.

2. The implantable rod according to claim 1, wherein the rod includes a central lumen extending axially from the trailing end into the body, the at least one side aperture being in communication with the lumen and the body being substantially solid in the first section.

3. The implantable rod according to claim 1, wherein a ratio of the axial length of the second threading to the second minor diameter is within the range of approximately 1.27 to 3.53.

4. The implantable rod according to claim 1, wherein the first section further comprises a first minor diameter, and a ratio of the axial length of the first threading to the first minor diameter is within the range of approximately 2.12 to 5.29.

5. The implantable rod according to claim 1, wherein the second major diameter is within the range of from about 10 mm to about 15 mm.

6. The implantable rod according to claim 1, wherein the first major diameter is no greater than about 98% of the second major diameter.

7. The implantable rod according to claim 1, wherein the elongated body has a length within the range of from about 1.25 inches to about 2.25 inches.

8. The implantable rod according to claim 1, wherein each of the first threading and the second threading has an axial length within the range of from about 0.5 inches to about 1.25 inches.

9. The implantable rod according to claim 1, wherein the intermediate section has an axial length within the range of from about 0.25 inches to about 0.5 inches.

10. The implantable rod according to claim 1, wherein the elongated body comprises stainless steel.

11. The implantable rod according to claim 1, wherein the elongated body comprises titanium.

12. The implantable rod according to claim 1, wherein the elongated body comprises a bioabsorbable material.

13. The implantable rod according to claim 1, wherein the elongated body comprises a lumen extending axially at least part way through the length of the elongated body.

14. The implantable rod according to claim 13, wherein the elongated body further comprises a plurality of side apertures in connection with the lumen.

15. The implantable rod according to any preceding claim, wherein each of the first threading and the second threading extends counterclockwise around the body.

16. The implantable rod according to any of claim 1, wherein each of the first threading and the second threading extends clockwise around the body.

17. The implantable rod according to claim 1, wherein each of the first threading and the second threading are self tapping.

18. The implantable rod according to claim 1, wherein the second major diameter is within the range of from about 12 mm to about 13 mm.

19. The implantable rod according to claim 1, wherein the first major diameter is about 9 mm.

20. The implantable rod according to claim 1, wherein the second thread pitch is within the range of from about 10 to about 15 turns per inch.

21. The implantable rod according to claim 1, wherein the first thread pitch is within the range of from about 10 to about 20 turns per inch.

22. The implantable rod according to claim 1, wherein the first thread pitch is at least about 105% finer than the second thread pitch.

23. The implantable rod according to claim 1, wherein the first thread pitch is at least about 110% finer than the second thread pitch.

24. The implantable rod according to claim 1, wherein the first thread pitch is at least about 125% finer than the second thread pitch.

25. The implantable rod according to claim 1, further comprising a releasable coupling, for releasably engaging a rotatable driver tool.