PIEZOELECTRIC IMPLANT

• US 20110118852A1
• Filed: 11/18/2010
• Published: 05/19/2011
• Est. Priority Date: 11/18/2009
• Status: Abandoned Application

• Current Assignee: DePuy Synthes Products LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Evans, David E.
• Application Number:
  US12/949,121
• Publication Number:
  US 20110118852A1
• Time in Patent Office: Days
• US Class Current: 623/24
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2002/2821 Bone stimulation by electromagnetic fields or electric current for enhancing ossification
• 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 2002/30087 piezoelectric
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30228 Cylinders of elliptical or oval basis
• CPC Class Codes: A61F 2002/30593 hollow
• 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 2002/30785 parallel
• CPC Class Codes: A61F 2002/30789 perpendicular with respect to each other
• CPC Class Codes: A61F 2230/0065 toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0069 cylindrical
• 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 2310/00059 Chromium or Cr-based alloys
• CPC Class Codes: A61F 2310/00131 Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00167 Diamond or diamond-like carbon
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00215 : containing silica or silicon oxide
• CPC Class Codes: A61F 2310/00227 : containing titania or titanium oxide
• CPC Class Codes: A61F 2310/00245 : containing niobium oxide
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00353 : Bone cement, e.g. polymethylmethacrylate or PMMA

Abstract

A piezoelectric implant configured to stimulate bone growth in surrounding bone, tissues, and/or bodily fluids. Anatomical loading of the piezoelectric implant causes the piezoelectric implant or components thereof to emit a signal, such as an electric current and/or electromagnetic field that promotes and/or enhances osteoblastic activity in the surrounding bone, tissues, and/or bodily fluids, thereby enhancing bone remodeling and/or fusion. The piezoelectric implant can be configured with a variety of piezoelectric components, such as individual piezoelectric elements or piezoelectric frames, and/or conductors configured to conduct the signal between the piezoelectric components and the surrounding bone, tissues, and/or bodily fluids.

Claims

1. A piezoelectric implant assembly comprising:

an implant body extending along a transverse direction between opposing upper and lower bone-facing surfaces; and

a piezoelectric component embedded in the implant body such that the piezoelectric component does not contact surrounding bone,

wherein when the implant body is subjected to an anatomical load, the piezoelectric component emits a signal that stimulates growth in the surrounding bone.

2. A piezoelectric implant assembly as recited in claim 1, wherein the piezoelectric component is completely embedded within the implant body.

3. A piezoelectric implant assembly as recited in claim 2, wherein the piezoelectric component comprises a piezoelectric frame.

4. A piezoelectric implant assembly as recited in claim 3, wherein the signal emitted by the piezoelectric frame comprises an electromagnetic field.

5. A piezoelectric implant assembly as recited in claim 2, wherein a conductor bore extends into the implant body from one of the upper or lower bone-facing surfaces, the conductor bore having an interior end exposing a portion of the piezoelectric component, and

wherein the implant assembly further comprises a conductor disposed in the conductor bore, the conductor having opposing upper and lower ends, the lower end configured to engage the exposed portion of the piezoelectric component, and the upper end configured to engage the surrounding bone, and

wherein the signal emitted by the piezoelectric component comprises an electrical current conducted from the piezoelectric component into the surrounding bone via the conductor.

6. A piezoelectric implant assembly as recited in claim 1, wherein the piezoelectric component comprises a piezoelectric frame.

7. A piezoelectric implant assembly as recited in claim 6, wherein the implant body defines a side surface between the upper and lower bone-facing surfaces along a perimeter of the implant body, and

wherein the piezoelectric frame is embedded in the side surface.

8. A piezoelectric implant assembly as recited in claim 6, wherein an implant bore extends through the implant body from the upper bone-facing surface through the lower bone-facing surface, the implant bore defining an inner bore surface, and

wherein the piezoelectric frame is embedded in the inner bore surface.

9. A piezoelectric implant assembly as recited in claim 1, wherein the piezoelectric component likewise emits the signal when an external electromagnetic signal is received by the piezoelectric component.

10. A piezoelectric implant comprising an implant body extending along a transverse direction between opposing upper and lower bone-facing surfaces,

wherein application of an anatomical load to the implant body causes the implant body to stimulate growth in surrounding bone.

11. A piezoelectric implant as recited in claim 10, wherein the implant body is constructed of a mixture of materials, the mixture comprising:

a non electrically conductive base material; and

a plurality of piezoelectric pieces.

12. A piezoelectric implant as recited in claim 11, wherein the implant is constructed such that the plurality of piezoelectric pieces are randomly distributed throughout the implant body.

13. A piezoelectric implant as recited in claim 10, wherein the implant body is constructed entirely of piezoelectric material.

14. A piezoelectric implant as recited in claim 10, wherein the implant body defines a side surface along an outer perimeter of the implant body extending between the upper and lower bone-facing surfaces, and

wherein at least one of the upper and lower bone-facing surfaces and the side surface are coated with a piezoelectric coating.

15. A method of stimulating bone growth, the method comprising:

inserting a piezoelectric implant between adjacent bony surfaces, the piezoelectric implant comprising an implant body, and a piezoelectric component embedded in the implant body such that the piezoelectric component does not contact the adjacent bony surfaces,

wherein when the implant body is subjected to an anatomical load, the piezoelectric component emits a signal that stimulates bone growth in the adjacent bony surfaces.

16. A method as recited in claim 15, wherein the signal is an electric current, and

wherein the piezoelectric implant further comprises a conductor disposed in the implant body, the conductor establishing an electrical connection between the piezoelectric component and at least one of the adjacent bony surfaces, such that the electric current flows from the piezoelectric component through the conductor and into the at least one of the adjacent bony surfaces.

17. A method as recited in claim 15, wherein the piezoelectric component is completely embedded within the implant body, and

wherein the signal comprises an electromagnetic field.