Intervertebral implant

• US 7,618,456 B2
• Filed: 05/22/2007
• Issued: 11/17/2009
• Est. Priority Date: 02/19/2002
• Status: Expired due to Term

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Cain, Christopher Marden John, Mathieu, Claude
• Primary Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US11/751,757
• Publication Number:
  US 20070219635A1
• Time in Patent Office: 910 Days
• Field of Search: 623 1711- 1716
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/8052 immobilised relative to screws by interlocking form of the heads and plate holes, e.g. conical or threaded
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30777 Oblong apertures
• 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 2250/0014 having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2310/00011 Metals or alloys

Abstract

The intervertebral implant is in the form of a three-dimensional structure (10) comprising (a) a top side (1) and an underside (2) which are designed to rest against the end plates of two adjacent vertebras, (b) a left side face (3) and a right side face (4), (c) a front face (5) and a rear face (6), (d) a horizontal center plane situated between the top side (1) and the underside (2), (e) a vertical center plane (8) situated between the left side face (3) and the right side face (8) and (f) a plurality of boreholes (9) passing through the implant structure (10) that are designed to receive longitudinal affixation elements (20), the axes (19) of said elements intersecting the horizontal center plane (7). At least one of the boreholes (9) is designed in a manner that the affixation element (10) received in it can be rigidly connected to the intervertebral implant. Said connection is implemented using a thread or by matching conical surfaces.

Claims

1. An intervertebral implant for implantation between an upper vertebra having an upper endplate and a lower vertebra having a lower endplate, the implant comprising:

a three dimensional structure having a first lateral side surface, a second lateral side surface, a posterior face, an anterior face, an upper surface and a lower surface, the upper and lower surfaces adapted to contact the upper and lower endplates respectively of the upper and lower vertebra, the three dimensional structure defining a first height between the upper and lower surfaces;

a plate having a top surface, a bottom surface and a horizontal center midplane, the plate contacting the anterior face of the three dimensional structure in an implanted configuration, the plate also including at least four boreholes, the at least four boreholes being internally threaded, the at least four boreholes comprising two upper boreholes and two lower boreholes, the two upper boreholes located between the horizontal center midplane and the top surface and the two lower boreholes located between the horizontal center midplane and the bottom surface, the plate defining a second height between the top and bottom surfaces, the first height being substantially equal to the second height;

at least two upper bone fixation elements and at least two lower bone fixation elements, each of the at least four upper and lower bone fixation elements including a head region having an external thread for engaging the internal thread formed in the at least four boreholes, and a shank region, the shank region adapted for engaging one of the upper and lower vertebra in the implanted configuration, the at least two upper bone fixation elements mounted in the two upper boreholes and the at least two lower bone fixation elements mounted in the two lower boreholes in the implanted configuration,

the head regions of the two upper bone fixation elements located between the top surface and the horizontal center midplane and the head regions of the two lower bone fixation elements located between the bottom surface and the horizontal center midplane in the implanted configuration, the shank region of the two upper bone fixation elements intersecting the upper surface of the three dimensional body and the shank region of the two lower bone fixation elements intersecting the lower surface of the three dimensional body in the implanted configuration,

the shank region of the two upper bone fixation elements being mutually laterally divergent with respect to one another and the shank regions of the two lower bone fixation elements being mutually laterally divergent with respect to one another in the implanted configuration.

2. The intervertebral implant of claim 1, wherein the head regions of the upper and lower bone fixation elements are entirely contained between the top and bottom surfaces of the plate in the implanted configuration.

3. The intervertebral implant of claim 1, wherein the anterior face of the three dimensional structure includes a recess for receiving the plate.

4. The intervertebral implant of claim 1, wherein the three dimensional structure and the plate are made from different biocompatible materials.

5. The intervertebral implant of claim 4, wherein the plate is made from a biocompatible metal and the three dimensional structure is made from a biocompatible plastic.

6. The intervertebral implant of claim 1, wherein the two upper and the two lower bone fixation elements are comprised of two upper and two lower bone screws, respectively.

7. The intervertebral implant of claim 1, wherein the three dimensional structure further comprises at least one opening, the at least one opening extending from the upper surface to the lower surface.

8. The intervertebral implant of claim 1, wherein the plate is slidably displaceable with respect to the three dimensional structure.