Cement-directing orthopedic implants

• US 7,465,318 B2
• Filed: 04/14/2005
• Issued: 12/16/2008
• Est. Priority Date: 04/15/2004
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Soteira, Inc. (Globus Medical, Inc.)
• Inventors: Sennett, Andrew R., Gruber, William Harwick, Richard, Joseph Ernest
• Primary Examiner(s): Robert; Eduardo C
• Assistant Examiner(s): CARTER, TARA ROSE E
• Application Number:
  US11/105,783
• Publication Number:
  US 20050261781A1
• Time in Patent Office: 1,342 Days
• Field of Search: 606/90, 606 92- 94, 606/198
• US Class Current: 623/17.12
• CPC Class Codes: A61B 17/00234 for minimally invasive surgery A61B17/0218, A61B17/0469, A61B17/12013, A61B17/1285, A61B17/29, A61B17/320016 take precedence
• CPC Class Codes: A61B 17/7098 wherein the implant is permeable or has openings, e.g. fenestrated screw hollow surgical screws A61B17/864
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• 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 2/4455 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 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2002/30006 differing in density or specific weight
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30583 filled with hardenable fluid, e.g. curable in-situ
• CPC Class Codes: A61F 2002/4635 using minimally invasive surgery
• CPC Class Codes: A61F 2210/0085 hardenable in situ, e.g. epoxy resins
• CPC Class Codes: A61F 2250/0015 differing in density or specific weight
• CPC Class Codes: A61F 2250/0023 differing in porosity

Abstract

A cement-directing structure for use in cement-injection bone therapy includes a collapsible, self-restoring braided structure with regions of differential permeability to the bone cement. The regions of differential permeability may be provided by areas where the braided mesh density is greater or lesser than surrounding areas and/or by means of a baffle. After the structure is placed in a void within a bony structure, cement is injected into the interior of the structure then oozes out in preferred directions according to the locations of the regions of differential permeability.

Claims

1. An expandable orthopedic device adapted for placement in a cavity formed in bone, comprising:

a collapsible, self expanding multi-layered braided mesh structure at least partially permeable to a bone cement, wherein the multi-layered braided mesh structure comprises primary members and secondary members; and

a baffle comprising at least one coating formed on at least a portion of the braided mesh structure, wherein the baffle is adapted to reduce permeability of that portion of the braided mesh structure, wherein the secondary members have been removed in at least one region of the device to form at least one cement flow window therethrough, and wherein the primary members remain over the at least one cement flow window.

2. The device of claim 1, wherein the baffle comprises a dip coating.

3. The device of claim 1, wherein the baffle is formed on an outer surface of the layered braided mesh structure.

4. The device of claim 1, wherein the primary members comprise elastic, heat-setting monofilament wire members.

5. The device of claim 1, wherein the primary members have sufficient mechanical strength and elasticity to self-expand toward their nominal shape upon complete insertion into a bone cavity.

6. The device of claim 1, wherein the secondary members comprise a polymer.

7. The device of claim 1, wherein at least one of the secondary members is more elastic than the primary members.

8. The device of claim 1, wherein the secondary members are layered over the primary members.

9. A method of treating a vertebral body comprising the steps of:

creating a cavity in a vertebral body;

inserting a collapsible, self expanding multi-layered braided mesh structure into the cavity, wherein the multi-layered braided mesh structure comprises;

primary members;

secondary members; and

a baffle comprising at least one coating formed on at least a portion of the braided mesh structure, wherein the baffle is adapted to reduce permeability of that portion of the braided mesh structure, wherein the secondary members have been removed in at least one region of the device to form at least one cement flow window therethrough, and wherein the primary members remain over the at least one cement flow window; and

a injecting a bone cement into the expanded braided mesh structure, wherein the bone cement flows preferentially out of the braided mesh structure through the at least one flow window.

10. The method of claim 9, wherein the baffle comprises a dip coating.

11. The method of claim 9, wherein the baffle is formed on an outer surface of the layered braided mesh structure.

12. The method of claim 9, wherein the primary members comprise elastic, heat-setting monofilament wire members.

13. The method of claim 9, wherein the primary members have sufficient mechanical strength and elasticity to self-expand toward their nominal shape upon complete insertion into a bone cavity.

14. The method of claim 9, wherein the secondary members comprise a polymer.

15. The method of claim 9, wherein at least one of the secondary members is more elastic than the primary members.

16. The method of claim 9, wherein the secondary members are layered over the primary members.