Artificial spinal unit assemblies

• US 20050033432A1
• Filed: 02/12/2004
• Published: 02/10/2005
• Est. Priority Date: 08/05/2003
• Status: Active Grant

• Current Assignee: Flexuspine Incorporated
• Original Assignee: Flexuspine Incorporated
• Inventors: Gordon, Charles, Harbold, Corey
• Granted Patent: US 7,909,869 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61B 17/7008 with parts of, or attached to, the longitudinal elements, bearing against an outside of the screw or hook heads, e.g. nuts on threaded rods A61B17/7007 takes precedence
• CPC Class Codes: A61B 17/7023 with a pivot joint
• CPC Class Codes: A61B 17/7032 Screws or hooks with U-shaped head or back through which longitudinal rods pass
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2002/30133 kidney-shaped or bean-shaped
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• 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 2002/30515 using a locking wedge or block
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/3055 for adjusting length
• 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 2002/30649 Ball-and-socket joints
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0015 : Kidney-shaped, e.g. bean-shaped
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness

Abstract

An artificial functional spinal unit is provided comprising, generally, an expandable artificial intervertebral implant that can be placed via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide an anatomically correct range of motion. Expandable artificial intervertebral implants in both lordotic and non-lordotic designs are disclosed, as well as lordotic and non-lordotic expandable cages for both PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) procedures. The expandable implants may have various shapes, such as round, square, rectangular, banana-shaped, kidney-shaped, or other similar shapes. By virtue of their posteriorly implanted approach, the disclosed artificial FSU'"'"'s allow for posterior decompression of the neural elements, reconstruction of all or part of the natural functional spinal unit, restoration and maintenance of lordosis, maintenance of motion, and restoration and maintenance of disc space height.

Claims

1. An expandable intervertebral implant comprising:

a lower body having an inferior and superior surface, the superior surface having a wall defining a recessed channel, and the wall having a hole defined therethrough;

an upper body having an inferior and superior surface, the inferior surface having at an angled projection extending downward into the recessed channel of the lower body;

a joint insert disposed within the recessed channel of the lower body and having an inferior and superior surface, the superior surface having an angled projection extending upward and in communication with the angled projection of the upper body; and

an expansion device capable of being inserted through the hole in the lower body such that upon insertion, the angled projection of the joint insert slidingly engages the angled projection of the upper body.

2. The expandable intervertebral implant of claim 1, wherein the lower body further comprises a plurality of holes defined through the wall defining the recessed channel, and a plurality of expansion devices are capable of being inserted through the plurality of holes.

3. The expandable intervertebral implant of claim 1, wherein the upper body further comprises a plurality of angled projections extending downward into the recessed channel, and the joint insert further comprises a plurality of angled projections extending upward and in communication with the plurality of angled projections of the upper body.

4. The expandable intervertebral implant of claim 1, wherein the upper body and the lower body are coupled.

5. The expandable intervertebral implant of claim 4, wherein the upper and lower bodies are couple via a captive peg.

6. The expandable intervertebral implant of claim 5, wherein the captive peg also secures the joint insert and allows rotation of the joint insert relative to the captive peg.

7. The expandable intervertebral implant of claim 1, wherein the superior surface of the upper body and the inferior surface of the lower body further comprises an osteoconductive scaffolding into which bone may grow.

8. The expandable intervertebral implant of claim 1, wherein the upper body and the lower body have substantially similar shapes.

9. The expandable intervertebral implant of claim 8, wherein the superior surface of the upper body and the superior surface of the lower body are substantially flat.

10. The expandable intervertebral implant of claim 1, wherein the lower body further comprises a a securing member coupled to the wall around the perimeter of the lower body and capable of rotating into a substantially perpendicular position, the securing member having a hole defined therethrough and capable of being fixedly attached to an adjacent vertebral body.

11. An artificial facet joint comprising:

an upper and lower multi-axial pedicle screw, both having a lockable head having a hole defined therethrough, the lockable head comprising a rod holding device that can be inserted into the lockable head, the rod holding device having a hole defined therethrough and substantially aligned with the hole defined through the lockable head, and a set screw that is engaged into the lockable head such that the rod holding device transfers force from the set screw to the lockable head; and

a rod having a central rod portion and two washer-type heads on each end of the central rod portion, the central rod portion slidingly positioned through the hole in the rod holding device such that the rod is allowed to translate and rotate within the rod holding device after the set screw has been engaged.

13. The artificial facet joint of claim 11, further comprising a cushioning material located within each hole and around the post-type heads.

14. The artificial facet joint of claim 11, wherein the post-type heads further comprise a locking device to prevent dislocation of the plate from the post-type heads.

12. An artificial facet joint comprising:

an upper and lower pedicle screw having a threaded bottom end and a post-type head; and

a plate having an upper end with a hole defined through and a lower end with a hole defined therethrough, each hole having an elongated shape, the plate being disposed above the upper and lower pedicle screws such that the post-type heads traverse each hole in the plate.