Methods for enhancing an interbody device

• US 8,414,820 B2
• Filed: 03/14/2012
• Issued: 04/09/2013
• Est. Priority Date: 02/01/2010
• Status: Active Grant

• Current Assignee: SB Technologies, LLC
• Original Assignee: SB Technologies, LLC
• Inventors: Bertele, Theodore P., Stanley, Scott K.
• Primary Examiner(s): HUSON, MONICA ANNE
• Application Number:
  US13/420,221
• Publication Number:
  US 20120167367A1
• Time in Patent Office: 391 Days
• Field of Search: 264/453
• US Class Current: 264/453
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• 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 2/46 Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
• 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 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30428 made by inserting a protrusion into a slot
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30482 using a locking cam
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30736 Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30911 : having a honeycomb structure
• CPC Class Codes: A61F 2002/30914 : Details of the mesh structure, e.g. disposition of the woven warp and weft wires
• CPC Class Codes: A61F 2002/30915 : made of a stack of bonded perforated sheets, grids or wire meshes
• CPC Class Codes: A61F 2002/3092 : having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/3093 : for promoting ingrowth of bone tissue
• CPC Class Codes: A61F 2002/30957 : using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30967 : Diffusion bonding
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/30973 : Two joined adjacent layers having complementary interlocking protrusions and recesses
• CPC Class Codes: A61F 2002/4631 : the prosthesis being specially adapted for being cemented
• 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 2310/00101 : Molybdenum or Mo-based alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: Y10T 29/49778 : with aligning, guiding, or instruction
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 29/49863 : with prestressing of part
• CPC Class Codes: Y10T 29/4998 : Combined manufacture including applying or shaping of fluent material

Abstract

A composite interbody device includes superior and inferior endplates with a plastic core molded therebetween. The core includes one or more features for permitting bone growth through the core. Each endplate includes a bone interface side coated with hydroxyapatite, for promoting bone on-growth. Pores in the bone interface sides permit bone in-growth. Core interface sides of the endplates include relatively larger pores for accepting molten material from the core, for example during injection molding, to enhance bonding of the endplates with the core. Each endplate has a central barrier layer for preventing the molten core material from extruding through the core interface pores into the bone interface pores, reserving the bone interface pores for bone in-growth. A method of manufacturing the composite interbody device is also disclosed.

Claims

1. A method for enhancing an interbody device, comprising:

securing a superior endplate having a porous bone interface surface to a superior surface of a preexisting interbody device, on a side opposite the bone interface surface; and

securing an inferior endplate having a porous bone interface surface to an inferior surface of the device, on a side opposite the bone interface surface;

each of the superior and inferior endplates comprising a central barrier layer and a porous device interface surface;

wherein securing the endplates to the device comprises applying the endplates to the interbody device as a composite coating; and

wherein securing each endplate to the device comprises applying a bonding agent to one or both of (a) the porous device interface surface and (b) the surface of the interbody device, the central barrier layer preventing diffusion of the bonding agent into the bone interface side.

2. Method of claim 1, wherein applying the endplates as a composite coating comprises (a) applying a solid barrier layer with each of the superior and inferior surfaces of the interbody device, and (b) layering or forming a porous bone interface layer over the solid barrier layer.

3. Method of claim 2 wherein applying the endplates further comprises applying a porous device interface layer to both the superior surface and the inferior surface of the interbody device, prior to applying the solid barrier layer and the bone interface layer.

6. Method of claim 1, wherein the bonding agent comprises a molten material.

7. Method of claim 1, wherein the bonding agent comprises a material of the superior and inferior surfaces of the preexisting interbody device, in a molten form.

8. Method of claim 1, the bonding agent being selected from the group of a molten or softened plastic and a biocompatible adhesive.

9. Method of claim 8, the molten or softened plastic comprising PEEK plastic.

4. A method for enhancing an interbody device, comprising:

securing a superior endplate having a porous bone interface surface with a superior surface of a preexisting interbody device, on a side opposite the bone interface surface; and

securing an inferior endplate having a porous bone interface surface with an inferior surface of the device, on a side opposite the bone interface surface;

wherein each of the superior and inferior endplates further comprises a central barrier layer and a porous device interface surface;

wherein securing the endplate to the device comprises applying a bonding agent to one or both of (a) the porous device interface surface and (b) the surface of the interbody device, the central barrier layer preventing diffusion of the bonding agent into the bone interface side; and

wherein securing the endplates with the device further comprises one or more of (a) press-fitting the endplates with the device, and (b) mechanically attaching the endplates with the device.

5. Method of claim 4, wherein mechanically attaching comprises aligning and joining lock and key features of the device with complimentary lock and key features of the endplates.

10. Method of claim 4, wherein the bonding agent comprises a molten material.

11. Method of claim 4, wherein the bonding agent comprises a material of the superior and inferior surfaces of the preexisting interbody device, in a molten form.

12. Method of claim 4, the bonding agent being selected from the group of a molten or softened plastic and a biocompatible adhesive.

13. Method of claim 12, the molten or softened plastic comprising PEEK plastic.

14. A method for enhancing an interbody device, comprising:

securing a superior endplate having a porous bone interface surface to a superior surface of a preexisting interbody device, on a side opposite the bone interface surface; and

securing an inferior endplate having a porous bone interface surface to an inferior surface of the device, on a side opposite the bone interface surface;

wherein securing the endplates to the device comprises applying the endplates to the interbody device as a composite coating by (a) applying a porous device interface layer to both the superior surface and the inferior surface of the interbody device, (b) applying a solid barrier layer over the porous device interface layer, and (c) layering or forming a porous bone interface layer over the solid barrier layer.