Craniofacial implant

• US 20060224242A1
• Filed: 06/02/2006
• Published: 10/05/2006
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Porex Surgical Incorporated (Stryker Corporation)
• Inventors: Swords, Greg, Noble, Aaron M.
• Granted Patent: US 8,298,292 B2
• Time in Patent Office: Days
• US Class Current: 623/17.190
• 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: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• 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 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2002/2878 for orbital repair
• CPC Class Codes: A61F 2002/30065 thermoplastic, i.e. softening or fusing when heated, and hardening and becoming rigid again when cooled
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/3096 trimmed or cut to a customised size
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0071 thermoplastic
• 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 2310/00323 containing titanium nitride
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61L 27/446 : with other specific inorganic fillers other than those covered by A61L27/443 or A61L27/46
• CPC Class Codes: A61L 27/56 : Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 23/06 : Polyethene

Abstract

A composite surgical implant that is made of a planar sheet of a thermoplastic resin that includes a top surface, a bottom surface, and a surgical grade metal mesh or metal plates contained therein. The implant may be bent by hand, wherein upon the displacement of the implant, the implant will generally maintain the shape to which it has been displaced.

Claims

1. A composite surgical implant comprising a top surface and a bottom surface, each surface comprising a layer of a polyolefin material, and a surgical grade metal mesh contained between the top and bottom surfaces, and said implant bendable or displaceable by manipulation by hand, wherein upon the displacement of said implant, said implant will generally maintain the shape to which it has been displaced.

2. The implant recited in claim 1, wherein the metal comprises titanium, surgical grade stainless steel, steel coated with titanium, titanium nitride, titanium alloyed with other metals, composites of any of the above materials, or any combination thereof.

3. The implant recited in claim 1, wherein polyolefin material comprises polyethylene, high density polyethylene, ultra high molecular weight polyethylene, polyether ether ketone, thermoplastic resins, polyethylene terephthalate, nylon, polypropylene, any polymer of aliphatic hydrocarbons containing one or more double bonds, composites of any of the above materials, or any combination thereof.

4. The implant recited in claim 1, wherein the top surface, the bottom surface, or both surfaces comprise a smooth barrier surface.

5. The implant recited in claim 1, wherein the top surface, the bottom surface, or both surfaces comprise a porous surface.

6. The implant recited in claim 1, wherein one of the top or bottom surfaces comprises a smooth barrier surface and the other of the top or bottom surfaces comprises a porous surface.

7. The implant recited in claim 5, wherein the pores of said porous surface are sized to allow for fibrovascular ingrowth.

8. The implant recited in claim 5, wherein pore sizes range from about 1 to about 1000 microns.

9. The implant recited in claim 1, further comprising one or more attachment structures adapted to attach the implant to a desired surface.

10. The implant as recited in claim 9, wherein the one or more attachment structures comprise openings in the mesh that will receive and engage the head of a surgical screw or surgical bone anchor.

11. The implant as recited in claim 9, wherein the one or more attachment structures comprise one or more strands of rings that are adapted to receive a fixation device.

12. The implant as recited in claim 9, wherein the one or more attachment structures are attached to the implant at one or more locations where the implant will be secured to bone.

13. The implant as recited in claim 9, wherein the one or more attachment structures comprise an angled bracket.

14. The implant as recited in claim 1, wherein the implant is provided in a particular shape to approximately fit a particular surgical site.

15. The implant as recited in claim 1, wherein the implant further comprises cells or biologically active molecules.

16. The implant as recited in claim 1, wherein the implant comprises openings, grooves, or channels that are adapted to accommodate nerves or vessels that may lie underneath the implant during use.

17. The implant as recited in claim 1, wherein the implant is provided in a kit of implants having varied features.

18. The implant of claim 17, wherein the varied features comprise one or more of varied thicknesses, mesh patterns, strengths, sizes, shapes, malleability, seeding options, or combinations thereof.

19. The implant of claim 1, wherein the metal mesh is sized to allow load bearing reconstructions of the mandible or long bones, and the polyolefin material provides volume filling capacity for resected or deficient bony structures, and provides a smooth surface over the metal component to minimize the possibility of implant exposure through the skin or soft tissues.

20. The implant of claim 1, wherein the surgical grade metal mesh has shape memory.

21. The implant of claim 1, wherein the surgical grade metal mesh comprises wire screen, expanded metal, perforated metal sheet, perforated bars, an interconnected meshwork of perforated bars, a grid, a free form solid, a perforated or machined shaped sheet, or any combination thereof.

22. A method of making a surgical implant comprising:

(a) placing a metallic mesh material in a bottom of a mold;

(b) introducing thermoplastic resin fines into said receptacle to allow said fines to fill the bottom of said mold and the interstitial spaces of the said mesh;

(c) placing a sheet of thermoplastic resin over said fines and said mesh;

(d) placing a mold top over said sheet and applying heat and pressure to said components contained in said mold to allow said fines to partially melt and to fuse to one another,

whereby an implant is constructed having a smooth barrier surface and an opposite porous surface.

23. The method of making an implant as recited in claim 22, wherein (a) comprises placing a thin sheet on the bottom surface of a cavity of said mold, whereby the implant created comprises barriers on opposite sides of said mesh.

24. A method of reconstruction of a bone defect comprising,

(a) bending a surgical implant having a top and bottom surface comprised of a polyolefin material and a metallic mesh embedded in the material to conform to the profile of said defect;

and

(b) mechanically attaching the implant to bone in proximity with the defect using attachment structures that extend from the implant.

25. The method of reconstruction recited in claim 24, wherein said defect is on the cranium.

26. The method of reconstruction recited in claim 25, wherein said implant further comprises a top smooth barrier surface and a bottom porous surface and said implant is positioned over a cranial defect with said top smooth barrier surface oriented away from the defect.

27. The method of reconstruction recited in claim 24, wherein said defect is in the orbit.

28. The method of reconstruction recited in claim 27, wherein said implant further comprises a top smooth barrier surface and a bottom porous surface and said implant is positioned in said orbit with said top smooth barrier surface oriented toward the orbital defect.

29. The method of reconstruction as recited in claim 24, wherein said attaching step comprises introduction of mechanical fasteners through said attachment structures and into said bone.

30. The method of reconstruction as recited in claim 29, wherein said mechanical fasteners comprise surgical screws.

31. The method of reconstruction recited in claim 24, further comprising cutting said implant to conform to the shape of said defect.

32. A kit for the repair of a bone defect, comprising

(a) one or more surgical implants comprising a top surface and a bottom surface, each surface comprising a layer of a polyolefin material and a surgical grade metal mesh contained between the top and bottom surfaces, and said implant bendable or displaceable by manipulation by hand;

and

(b) one or more aids for shaping the implant.

33. The kit of claim 32, wherein the surgical implants are provided in one or more different sizes, shapes, or thicknesses and/or having one or more different fastening devices or attachment structures.

34. The kit of claim 32, wherein the one or more aids to shaping the implant comprises a clear template of the implant shape upon which the surgeon may trace the defect, cut it out of the clear plastic template, and transfer the defect shape to the implant before cutting the implant to size.

35. The kit of claim 32, further comprising:

(c) scissors for cutting the template and/or trimming the implant and instructions for the use of the implant.