Device and method for lumbar interbody fusion

• US 6,730,126 B2
• Filed: 02/12/2003
• Issued: 05/04/2004
• Est. Priority Date: 11/13/2000
• Status: Expired due to Fees

• Current Assignee: Benedetta Delorenzo Melnick, Frank H. Boehm Jr
• Original Assignee: Benedetta Delorenzo Melnick, Frank H. Boehm Jr
• Inventors: Melnick, Benedetta Delorenzo, Boehm, Frank H. Jr.
• Primary Examiner(s): Philogene, Pedro
• Assistant Examiner(s): BONDERER, DAVID A
• Application Number:
  US10/365,187
• Publication Number:
  US 20030176926A1
• Time in Patent Office: 447 Days
• Field of Search: 623/17.15, 623/17.16
• US Class Current: 623/17.15
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61B 2050/005 with a lid or cover
• CPC Class Codes: A61B 50/33 Trays
• CPC Class Codes: A61F 2/0095 Packages or dispensers for prostheses or other implants for intraocular lenses A61F2/1691; for dental surgery A61C19/02
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• 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 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 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30237 partial tubes
• CPC Class Codes: A61F 2002/30372 with additional means for limiting said translation
• CPC Class Codes: A61F 2002/30492 using a locking pin
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• 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 2002/30975 made of two halves
• 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 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• 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 2310/00359 : Bone or bony tissue
• CPC Class Codes: Y10S 606/914 : Toolkit for installing or removing spinal positioner or stabilizer

Abstract

A method for performing percutaneous interbody fusion is disclosed. The method includes the steps of inserting a guide needle posteriorly to the disc space, inserting a dilator having an inner diameter slightly larger than the outer diameter of the guide needle over the guide needle to the disc space to enlarge the disc space, and successively passing a series of dilators, each having an inner diameter slightly larger than the outer diameter of the previous dilator, over the previous dilator to the disc space the gradually and incrementally increase the height of the disc space. Once the desired disc height is achieved, the guide needle and all the dilators, with the exception of the outermost dilator, are removed. An expandible intervertebral disc spacer is then passed through the remaining dilator and positioned in the disc space. Th disc spacer is expanded to the required disc height, and then a bone matrix is passed through the dilator to fill the disc space. The dilator is then removed. An expandible intervertebral disc spacer is also disclosed, having a tapered bore that causes greater expansion of one end of the spacer with respect to the other. A kit for performing the percutaneous interbody fusion procedure is also disclosed.

Claims

1. An expandible intervertebral disc spacer, comprising:

a split cylinder having a top half and a bottom half joined by a plurality of pins to permit movement of the top half with respect to the bottom half, an inner surface of the top half and an inner surface of the bottom half facing each other defining a tapered bore extending from a first end of the cylinder towards a second end of the cylinder; and

a piston screw insertable into the tapered bore to expand the cylinder by moving the top half away from the bottom half;

wherein the piston screw moving into the taperd bore causes the second end of the cylinder to expand a greater distance than the first end.

2. An expandible intervertebral disc spacer for implantation in a disc space to enlarge the height of the disc space and restore lordosis in a spine of a patient during interbody fusion procedures, comprising:

a top portion having an inner surface and an outer surface, and having a first end and a second end;

a bottom portion having an inner surface and an outer surface, and having a first end and a second end, the inner surface of the bottom portion facing the inner surface of the top portion;

a plurality of pins joining the top portion to the bottom portion to permit vertical movement of the top portion with respect to the bottom portion;

the inner surface of the top portion and the inner surface of the bottom portion defining a tapered bore having a diameter at a first end that is greater than a diameter at a second end; and

a rod for insertion into the tapered bore to expand a distance between the top portion and the bottom portion, the second end of the top portion moving a greater distance with respect to the second end of the bottom portion than the first end.

3. The disc spacer of claim 2, wherein the tapered bore is threaded along at least a portion of its length.

4. The disc spacer of claim 3, wherein the rod is threaded.

5. The disc spacer of claim 2, wherein the top portion and bottom portion are constructed of bone material.

6. The disc spacer of claim 2, wherein the outer surface of the top portion and the outer surface of the bottom portion are scored to enhance adherence to vertebra of the spine.