Composite perforated implant structures

• US 5,380,328 A
• Filed: 08/09/1993
• Issued: 01/10/1995
• Est. Priority Date: 08/09/1993
• Status: Expired due to Fees

• Current Assignee: Sofamor Danek Properties, Inc. (Medtronic Plc)
• Original Assignee: TiMesh, Inc. (Medtronic Plc)
• Inventors: Morgan, Frank H.
• Primary Examiner(s): Sykes, Angela D.
• Application Number:
  US08/103,541
• Time in Patent Office: 519 Days
• Field of Search: 128/897-899, 606/69-71, 606/86, 606/104, 623/11, 623/16-23, 623/66
• US Class Current: 606/70
• CPC Class Codes: A61B 17/8071 for the jaw
• CPC Class Codes: A61B 17/8085 with pliable or malleable elements or having a mesh-like structure, e.g. small strips A61B17/8071, A61B17/8076 take precedence
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/2846 Support means for bone substitute or for bone graft implants, e.g. membranes or plates for covering bone defects nets or sleeves applied to surface of endoprostheses A61F2/30907; bone plates A61B17/80; bone regeneration in dental surgery A61C8/0006
• CPC Class Codes: A61F 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30785 parallel
• 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 2220/005 using adhesives
• CPC Class Codes: A61F 2310/00401 Coating made of iron, of stainless steel or of other Fe-based alloys
• CPC Class Codes: A61F 2310/00407 Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00413 Coating made of cobalt or of Co-based alloys
• CPC Class Codes: A61L 27/306 Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: A61L 27/48 with macromolecular fillers

Abstract

A composite surgical implant structure for use orthognathic and reconstructive surgery, for the correction cranial defects, and for reconstructive preprosthetic oral maxillofacial surgery, the implant structure is comprised of at least one layer of perforated, biocompatible metallic sheet material (preferably pure pliable titanium) and at least one layer of biologically and chemically inert microporous membrane material in intimate contact with, and supported by, the layer of perforated metallic sheet material. The microporous membrane material is comprised of randomly dispersed polytetrafluoroethylene fibers, or mixtures of cellulose acetate and cellulose nitrate fibers, or polyvinylidine difluoride fibers and the material has a pore size such that desired biological nutrients are permitted passage through the implant structure and unwanted biological cells are precluded from passage therethrough, The layers of perforated metallic sheet material and microporous membrane material are maintained together to form the composite structure by a biocompatible adhesive, heat fusion of the fibers of the membrane material or mechanical fasteners interacting between the layers. The implant structure is particularly applicable to use for the guided regeneration and enlargement of bone tissue at surgical sites.

Claims

1. A composite surgical implant structure for use in orthognathic and reconstructive surgery and for the correction of cranial defects of human patients comprising:

a) at least one layer of perforated and pliable, biocompatible metallic sheet material wherein the perforations are of a size such that bone screws may be inserted therethrough and into hard and soft tissues of a human patient; and

b) at least one layer of biologically and chemically inert microporous membrane sheet material of like size and configuration in intimate contact with, supported by, and covering said at least one layer of perforated metallic sheet material, said at least one layer of microporous membrane material being comprised of randomly dispersed polytetrafluoroethylene fibers having a pore size in the range of from about 0.2 to about 3.0 microns whereby desired biological nutrients are permitted passage through the pores of said membrane material and the perforations of said metallic sheet material of said implant structure to underlying hard and soft tissues of said human patient and unwanted biological cells and bacteria are precluded from passage through said implant structure to said tissues.

3. The composite surgical implant structure as claimed in claim 1 wherein said at least one layer of perforated and pliable, biocompatible metallic sheet material is comprised of a mesh-type metallic plate including a multiplicity of square perforations arranged uniformly in lines and rows.

4. The composite surgical implant structure as claimed in claim 1 wherein said at least one layer of perforated and pliable, biocompatible metallic sheet material is comprised of a metallic plate having a grid of legs forming a multiplicity of open geometric spaces with said legs connected to one-another in affixation sections which each include a screw hole for accepting a bone screw as may be inserted therethrough, said open spaces comprising at least 50% of the surface area of said metallic plate.

5. The composite surgical implant structure as claimed in claim 1 wherein said perforated, biocompatible metallic sheet material is comprised of a pliable perforated metal plate off pure titanium having a thickness range of from about 0.05 to about 2.0 mm.

6. The composite surgical implant structure as claimed in claim 1 wherein said implant structure is comprised of a single layer of said perforated and pliable metallic sheet material and a single layer of said microporous membrane sheet material, said layers being affixed to one another by means selected from the group consisting of:

biocompatible adhesives having an adhesive affinity for said perforated metallic sheet material and said membrane material and applied only the interfacing surface areas of said metallic shear material leaving the pores of said membrane material proximate the perforations of said metallic sheet material open, heat fusion of the fibers of said membrane material to the interfacing surface areas of said metallic sheet material, and bone screws interacting between said layers.

7. The composite surgical implant structure as claimed in claim 1 wherein said implant structure is comprised of a sandwich-type arrangement of layers including outer layers of said perforated metallic sheet material and an intermediate layer of said microporous membrane sheet material.

8. The composite surgical implant structure as claimed in claim 1 wherein said implant structure is comprised of a sandwich-type arrangement of layers including outer layers of said microporous membrane sheet material and an intermediate layer of said perforated metallic sheet material.

9. The composite surgical implant structure as claimed in claim 1 wherein said perforated, biocompatible metallic sheet material is selected from the group consisting of titanium, titanium alloys, cobalt-chrome alloys and stainless steel.

10. The composite surgical implant structure as claimed in claim 1 wherein said perforated and pliable, biocompatible metallic sheet material is comprised of pliable woven titanium wire mesh material having from about 8 to about 16 openings per linear inch in both directions.

2. The composite surgical implant structure as claimed in claim 2 wherein said membrane material has a pore size in the range of from about 0.4 to about 0.6 microns.

11. A composite surgical implant structure for use in orthognathic and reconstructive surgery, for the correction of cranial defects, and for the guided regeneration and enlargement of bone tissue of human patients, said implant structure comprising:

a) at least one layer of biocompatible and pliable metallic sheet material selected from the group consisting titanium, titanium alloys, cobalt-chrome alloys and stainless steel, said metallic sheet material including a multiplicity uniformly arranged mesh-type perforations of a size such that mechanical fasteners may be inserted therethrough and into bone tissue of a human patient; and

b) at least one layer of biologically and chemically inert microporous membrane sheet material of like size configuration comprised of randomly dispersed polytetrafluoroethylene fibers, said at least one layer of said microporous membrane sheet material being in intimate contact with, supported by, and covering said at least one layer of metallic sheet material, and said at least one layer of membrane sheet material having a pore size in the range of about 0.2 to about 3.0 microns whereby desired biological nutrients for bone regeneration are permitted passage through the pores of said membrane material and the perforations of said metallic sheet material of said implant structure underlying bone and unwanted biological cells and bacteria are precluded from passage through said implant structure to underlying bone.

12. The composite surgical implant structure as claimed in claim 11 wherein said microporous membrane material has pore size in the range of from about 0.4 to about 0.6 microns.

13. The composite surgical implant structure as claimed in claim 11 wherein said layer of metallic sheet material is comprised of a plate of pure titanium having a thickness range of from about 0.05 to about 2.0 mm and said layer of microporous membrane material has a thickness range of from about 0.1 to about 1.0 min.

14. The composite surgical implant structure as claimed in claim 11 wherein said implant structure is comprised of a sandwich-type arrangement of three layers including outer layers of said metallic sheet material and an intermediate layer of said microporous membrane material.

15. The composite surgical implant structure as claimed in claim 11 wherein said implant structure is comprised of a sandwich-type arrangement of three layers including outer layers of said microporous membrane material and an intermediate layer of said metallic sheet material.

16. A composite surgical implant structure for use in orthognathic and reconstructive surgery, for the correction of cranial defects, and for reconstructive preprosthetic oral and maxillofacial surgery of bone tissue of human patients comprising:

a) at least one layer of perforated and pliable, biocompatible metallic sheet material wherein the perforations in said sheet material are of a size such that mechanical fasteners may be inserted therethrough and into bone tissue of a human patient; and

b) at least one layer of microporous membrane sheet material of like size and configuration in intimate contact with, supported by, and covering said at least one layer of said perforated metallic sheet material, said microporous membrane sheet material being selected from the group of biologically and chemically inert sheet materials consisting of polytetrafluoroethylene fibers, mixtures of cellulose acetate and cellulose nitrate fibers and polyvinylidine difluoride fibers, and said at least one layer of microporous membrane sheet material having a pore size in the range of from about 0.2 to about 3.0 microns whereby desired biological nutrients are permitted passage through the pores of said membrane material and the perforations of said metallic sheet material of said implant structure to underlying bone tissues of said patient and unwanted biological cells and bacteria are precluded from passage through said implant structure to said tissues.