Expandable lordosis stabilizing cage

• US 7,879,098 B1
• Filed: 06/21/2006
• Issued: 02/01/2011
• Est. Priority Date: 10/19/2005
• Status: Expired due to Fees

• Current Assignee: James W. Simmons Jr
• Original Assignee: James W. Simmons Jr
• Inventors: Simmons, James W. Jr.
• Primary Examiner(s): Robert; Eduardo C
• Assistant Examiner(s): CARTER, TARA ROSE E
• Application Number:
  US11/471,882
• Time in Patent Office: 1,686 Days
• Field of Search: 623/17.11, 623/16.11, 623/17.16, 606/72, 606/73, 606246-249
• US Class Current: 623/17.11
• 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 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• 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 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30736 Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30831 perpendicular with respect to each other
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• 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 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• 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

Abstract

An expandable stabilizing cage includes a body having a fixed cage section, an expandable cage section, formed as a number of elongate blocks, and a relief between the fixed and expandable cage sections. An orifice, which through the expandable cage section decreases in diameter with increased distance along the central axis of the body away from the fixed cage section, is provided through the body. The expandable stabilizing cage also includes a wafer, which, when inserted into the orifice through the body, causes outward flaring of the elongate bars for fixing the expandable stabilizing cage securely in place in the intervertebral disc space between two adjacent vertebral bodies. Upper elongate blocks have substantially planar upper surfaces. Lower elongate blocks have substantially planar lower surfaces. The surfaces may be provided with surface irregularities for facilitating stable engagement with adjacent vertebral bodies, exemplary irregularities including denticles, dimples, scores, grooves or small protuberances.

Claims

1. An expandable stabilizing cage for insertion into the intervertebral disc space of a patient for establishing and maintaining a desired lordosis, said expandable stabilizing cage comprising:

a body having a fixed cage section, an expandable cage section and a relief between said fixed cage section and said expandable cage section, said expandable cage section comprising an upper pair of elongate blocks projecting from said fixed cage section and a lower pair of elongate blocks projection from said fixed cage section, each said pair having a left elongate block and a right elongate block, wherein;

each one of said upper pair of elongate blocks comprises a substantially planar top surface;

each one of said lower pair of elongate blocks comprises a substantially planar bottom surface;

said upper pair of elongate blocks is separated from said lower pair of elongate blocks by a first longitudinal slot through said expandable cage section, said first longitudinal slot being positioned in a horizontal plane parallel with said central axis; and

said left elongate blocks are separated from said right elongate blocks by a second longitudinal slot through said expandable cage section, said second longitudinal slot being positioned in a vertical plane parallel with said central axis;

an orifice through said body, said orifice being coaxial with a central longitudinal axis through said fixed cage section and said expandable cage section of said body;

an expansion wafer; and

wherein;

said relief comprises an annulus formed coaxially about said orifice through said body, said annulus having an outside diameter that is less than the height top to bottom of said expandable cage section and is less than the width side to side of said expandable cage section, wherein;

each said elongate block comprises and end face; and

each said elongate block interconnects with said fixed cage section at said annulus through a fractional portion of said end face of each respective elongate block;

each one of said upper pair of elongate blocks is positioned generally above one of said lower pair of elongate blocks;

a portion of said orifice through said expandable cage section is shaped in the form of a frustum of a cone, said portion of said orifice decreasing in diameter with increasing distance from said fixed cage section; and

insertion of said expansion wafer into said orifice and from said fixed cage section into and through said expandable cage section causes radially outward flaring of said elongate blocks, said radially outward flaring causing said substantially planar surfaces of said elongate blocks to move nearer the vertebral bodies bounding the intervertebral disc space of the patient.

2. The expandable stabilizing cage as recited in claim 1, wherein said upper surfaces of said upper pair of elongate blocks and said lower surfaces of said lower pair of elongate blocks are provided with surface irregularities for facilitating stable engagement of said elongate blocks with adjacent vertebral bodies.

3. The expandable stabilizing cage as recited in claim 2, wherein said surface irregularities comprise denticles.

4. The expandable stabilizing cage as recited in claim 3, wherein said denticles are arranged transverse to said central longitudinal axis.

5. The expandable stabilizing cage as recited in claim 2, wherein said surface irregularities comprise dimples.

6. The expandable stabilizing cage as recited in claim 2, wherein said surface irregularities comprise scores.

7. The expandable stabilizing cage as recited in claim 2, wherein said surface irregularities comprise grooves.

8. The expandable stabilizing cage as recited in claim 2, wherein said surface irregularities comprise protuberances.

9. The expandable stabilizing cage as recited in claim 1, wherein a portion of said orifice through said body is provided with threading.

10. The expandable stabilizing cage as recited in claim 9, wherein said expansion wafer comprises a disc, said disc being circumferentially threaded.

11. The expandable stabilizing cage as recited in claim 10, wherein said expansion wafer comprises a drive on a first face thereof.

12. The expandable stabilizing cage as recited in claim 11, wherein said drive comprises a socket centrally provided on said first face.

13. The expandable stabilizing cage as recited in claim 12, wherein said socket comprises a hexagonal socket.

14. The expandable stabilizing cage as recited in claim 13, wherein said drive comprises a slot.

15. The expandable stabilizing cage as recited in claim 1, said expandable stabilizing cage further comprising an end plug for insertion into said orifice adjacent said fixed cage section.

16. The expandable stabilizing cage as recited in claim 1, wherein said expandable cage section comprises a generally rectangular transverse cross section.

17. The expandable stabilizing cage as recited in claim 1, wherein said expandable cage section comprises a generally square transverse cross section.