Zero-profile interbody spacer and coupled plate assembly

• US 9,414,935 B2
• Filed: 04/17/2015
• Issued: 08/16/2016
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Inventors: McDonough, William P., Strausbaugh, William L., Bonner, Christopher, Pepe, Thomas, Meili, Ralph, Hunziker, Markus, Jeger, Michael, Kueenzi, Thomas, Koch, David, Ponzer, Rainer, Richter, Joern, Berger, Roger
• Primary Examiner(s): Truong, Kevin T
• Assistant Examiner(s): Ku, Si Ming
• Application Number:
  US14/689,614
• Publication Number:
  US 20150216675A1
• Time in Patent Office: 487 Days
• Field of Search: 623/17.11, 623/17.16, 606/86.A, 606/86.B
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/8033 having indirect contact with screw heads, or having contact with screw heads maintained with the aid of additional components, e.g. nuts, wedges or head covers
• CPC Class Codes: A61B 17/8042 the additional component being a cover over the screw head
• 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 17/8057 the interlocking form comprising a thread
• CPC Class Codes: A61B 17/809 with bone-penetrating elements, e.g. blades or prongs bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 17/88 Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices A61B17/7074 takes precedence
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30505 spring biased
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30517 using a locking plate
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• 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 2002/448 : 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 2002/4615 : of spacers
• CPC Class Codes: A61F 2220/0016 : with sharp anchoring protrusions, e.g. barbs, pins, spikes
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0034 : D-shaped
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

An implant for insertion into a disc space between vertebrae, wherein the implant includes a spacer portion, a plate portion coupled to the spacer portion, two bone fixation elements for engaging the vertebrae and a retention mechanism for preventing the bone fixation elements from postoperatively backing-out of the plate portion. The retention mechanism may be in the form of a spring biased snapper element that is biased into communication with the bone fixation elements so that once the bone fixation element advances past the snapper element, the snapper element is biased back to its initial position in which the snapper element interfaces with the bone fixation elements. Alternatively, the retention mechanism may be in the form of a propeller rotatable between a first position in which the bone fixation elements are insertable to a second position where the bone fixation elements are prevented from backing-out.

Claims

1. An intervertebral implant comprising:

a spacer portion defining a spacer trailing surface, a spacer leading surface opposite the spacer trailing surface, a first side surface, a second side surface opposite the first side surface, and an inner surface, the inner surface including a first portion that is opposite the first side surface, a second portion that is opposite the spacer leading surface, and a third portion that is opposite the second side surface;

a plate portion defining a plate trailing surface and a plate leading surface opposite the plate trailing surface in a first direction, the plate portion configured to be coupled to the spacer portion such that the plate leading surface and the inner surface define an opening configured to

receive bone graft material;

wherein the plate portion includes a top surface configured to face a first vertebral body when the intervertebral implant is implanted and a bottom surface configured to face a second vertebral body when the intervertebral implant is implanted, the bottom surface opposite the top surface along a second direction that is perpendicular to the first direction;

wherein the plate portion defines a recess configured to receive an implant insertion tool, the recess partially defined by the plate trailing surface such that the recess extends into the plate trailing surface toward the plate leading surface and terminates at a first surface that faces in a direction opposite the first direction, and the recess partially defined by the top surface such that the recess extends into the top surface and terminates at a second surface that faces in a direction opposite the second direction.

2. The intervertebral implant of claim 1, wherein the plate portion includes a first projection and a second projection that each extend from the plate leading surface in the first direction, each of the first projection and the second projection configured such that when the plate portion is coupled to the spacer portion, a portion of the spacer portion is positioned between the first projection and the second projection.

3. The intervertebral implant of claim 2, wherein the spacer portion includes a first recess and a second recess that are each configured to receive one of the first projection and the second projection to couple the spacer portion to the plate portion.

4. The intervertebral implant of claim 1, wherein the spacer portion includes a first material, the plate portion includes a second material, and the first material is different than the second material.

5. The intervertebral implant of claim 4, wherein the first material is a non-metallic material and the second material is a metallic material.

6. The intervertebral implant of claim 1, wherein the spacer portion defines a spacer top surface configured to face a first vertebral body when the intervertebral implant is implanted and a spacer bottom surface configured to face a second vertebral body when the intervertebral implant is implanted, the spacer bottom surface opposite the spacer top surface in a second direction that is perpendicular to the first direction when the plate portion is coupled to the spacer portion, and the opening extends through both the spacer top surface and the spacer bottom surface.

7. The intervertebral implant of claim 1, wherein the recess is a first recess, and the plate portion defines a second recess configured to receive the implant insertion tool, the second recess partially defined by the plate trailing surface such that the second recess extends into the plate trailing surface toward the plate leading surface and terminates at a third surface that faces in the direction opposite the first direction, and the second recess partially defined by the bottom surface such that the second recess extends into the bottom surface and terminates at a fourth surface that faces in the second direction.

8. An intervertebral implant comprising:

a spacer portion defining a spacer trailing surface and a spacer leading surface opposite the spacer trailing surface; and

a plate portion defining a plate trailing surface and a plate leading surface opposite the plate trailing surface in a first direction, the plate portion further defining a top surface, a bottom surface opposite the top surface in a second direction, and a plate body that extends from the plate trailing surface to the plate leading surface and that further extends from the top surface to the bottom surface, the plate portion configured to be coupled to the spacer portion such that the plate leading surface faces the spacer trailing surface, the plate portion defining a recess configured to receive an implant insertion tool, the recess partially defined by the plate trailing surface such that the recess extends into the plate body toward the plate leading surface and terminates at a first surface that faces in a direction opposite the first direction, and the recess partially defined by the top surface such that the recess extends into the plate body and terminates at a second surface that faces in a direction opposite the second direction.

9. The intervertebral implant of claim 8, wherein a first distance from the second surface to the top surface measured along a straight line that is parallel to the second direction is less than a second distance from the second surface to the bottom surface measured along the straight line.

10. The intervertebral implant of claim 9, wherein a third distance from the first surface to the plate trailing surface measured along a straight line that is parallel to the first direction is less than a fourth distance from the first surface to the plate leading surface measured along the straight line that is parallel to the first direction.

11. The intervertebral implant of claim 8, wherein the recess is a first recess, and the plate portion defines a second recess configured to receive the implant insertion tool, the second recess partially defined by the plate trailing surface such that the second recess extends into the plate body toward the plate leading surface and terminates at a third surface that faces in the direction opposite the first direction, and the second recess partially defined by the bottom surface such that the second recess extends into the plate body and terminates at a fourth surface that faces in the second direction.

12. The intervertebral implant of claim 11, wherein a first distance from the second surface to the top surface measured along a first straight line that is parallel to the second direction is less than a second distance from the second surface to the bottom surface measured along the first straight line, and a third distance from the fourth surface to the bottom surface measured along a second straight line that is parallel to the second direction is less than a fourth distance from the fourth surface to the top surface measured along the second straight line.

13. The intervertebral implant of claim 12, wherein the first distance is equal to the third distance, and the second distance is equal to the fourth distance.

14. The intervertebral implant of claim 12, wherein a fifth distance from the first surface to the plate trailing surface measured along a first straight line that is parallel to the first direction is less than a sixth distance from the first surface to the plate leading surface measured along the first straight line that is parallel to the first direction, and a seventh distance measured along a second straight line that is parallel to the first direction is less than an eighth distance from the first surface to the plate leading surface measured along the second straight line that is parallel to the first direction.

15. The intervertebral implant of claim 14, wherein the fifth distance is equal to the seventh distance, and the sixth distance is equal to the eighth distance.

16. The intervertebral implant of claim 11, wherein the intervertebral implant is configured to be inserted in an intervertebral disc space between an upper vertebral body and a lower vertebral body such that the top surface faces the upper vertebral body and the bottom surface faces the lower vertebral body, and the plate portion defines a bone fixation hole configured to receive a bone fixation element to secure the implant to one of the superior and inferior vertebral bodies.

17. The intervertebral implant of claim 16, further comprising a retention mechanism configured to prevent a bone fixation element that is inserted in the bone fixation hole from backing out of the bone fixation hole.

18. The intervertebral implant of claim 17, wherein the retention mechanism includes a borehole that is defined by the plate portion, and the borehole is spaced from both the first recess and the second recess.