Fenestrated surgical anchor and method

• US 6,554,830 B1
• Filed: 04/10/2000
• Issued: 04/29/2003
• Est. Priority Date: 04/10/2000
• Status: Expired due to Term

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Chappius, James L.
• Primary Examiner(s): O'Connor, Cary E.
• Application Number:
  US09/545,920
• Time in Patent Office: 1,114 Days
• Field of Search: 623/17.11, 623/17.16, 606/60, 606/61, 606/65, 606/73, 606/92, 606/93, 606/94
• US Class Current: 606/246
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• 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: A61B 17/8635 Tips of screws
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body

Abstract

Preferably, each anchor incorporates a passage for receiving boding cement therein. The passage communicates with one or more fenestrations or holes, preferably formed at the distal end of the anchor, that allow the bonding cement to pass from and disperse about the anchor. Since at least some of the bonding cement received in the passage passes from the anchor and, preferably, into the material of the skeletal member to which the anchor is engaged, a firm fixation or anchoring of the anchor within the skeletal member is facilitated.

Claims

1. A surgical anchor for anchoring within a vertebral body using bonding cement, said anchor comprising:

an elongated body having a proximal end and a distal end;

a passage extending at least partially through said body from said proximal end;

at least one hole extending at least partially through said body and communicating with said passage;

said passage and said at least one hole configured such that bonding cement is receivable in said passage at said proximal end, deliverable through said passage, through said at least one hole and into said vertebral body; and

a plug member having first and second end walls and a side wall extending therebetween, said plug member being receivable about said elongated body such that said plug member is engagable with said vertebral body to substantially prevent movement of said proximal end of said elongated body relative to said vertebral body.

2. The surgical anchor of claim 1, wherein each of said at least one hole is formed along a distal most one-third of said elongated body.

3. The surgical anchor of claim 1, wherein said passage extends partially through said elongated body to define a partially cannulated surgical anchor.

4. The surgical anchor of claim 1, wherein said anchor is formed as a pedicle anchor configured to anchor within the vertebral body.

5. The surgical anchor of claim 1, wherein said elongated body has external threads formed along at least a distal end portion thereof, each of said at least one hole being arranged along a distal most one-third of said external threads.

6. The surgical anchor of claim 1, wherein said elongate body is substantially cylindrical in shape.

7. A method for anchoring a surgical anchor to a vertebral body, comprising:

providing a surgical anchor having a proximal end, a distal end, an axial passage extending from the proximal end toward the distal end, and at least one lateral opening communicating with the axial passage, the surgical anchor including an enlarged proximal end portion;

inserting at least a portion of the surgical anchor into the vertebral body;

engaging the enlarged proximal end portion of the surgical anchor at least partially within the vertebral body to substantially prevent movement of the proximal end portion of the surgical anchor relative to the vertebral body; and

delivering a bonding cement through the axial passage of the surgical anchor, through the at least one lateral opening and into the vertebral body.

8. The method of claim 7, wherein the enlarged proximal end portion of the surgical anchor is outwardly tapered in a proximal direction.

9. The method of claim 8, wherein the enlarged proximal end portion of the surgical anchor is defined by a plug member having opposite end walls, an outwardly tapered side wall, and an axial bore extending between the end walls;

and

further comprising positioning the surgical anchor within the axial bore of the plug member prior to the inserting.

10. The method of claim 7, wherein the axial passage extends partially through the surgical anchor;

and

wherein the delivering includes distributing the bonding cement entirely through the at least one lateral opening.

11. A system for anchoring a surgical anchor to a vertebral body;

comprising;

a surgical anchor having a proximal end and a distal end, an axial passage extending from said proximal end toward said distal end, at least one lateral opening communicating with said axial passage, and an enlarged proximal end portion engagable within the vertebral body to substantially prevent movement of said proximal end portion relative to the vertebral body, said enlarged proximal end portion of the surgical anchor comprising a plug member having opposite end walls, a side wall, and an axial bore extending between said end walls that is sized and shaped to receive said surgical anchor therethrough; and

a supply of bonding cement deliverable through said axial passage, out said at least one lateral opening and into the vertebral body.

12. The method of claim 11, wherein said side wall of said plug member is outwardly tapered in a proximal direction.

13. The system of claim 11, wherein said surgical anchor includes a head adapted to abut one of said end walls of said plug member to engage said plug member within the vertebral body.

14. The system of claim 11, wherein said axial passage extends partially through the surgical anchor such that said bonding cement is deliverable entirely through said at least one lateral opening.

15. The system of claim 11, wherein said bonding cement produces an exothermic reaction during curing;

and

wherein said surgical anchor defines external threads along substantially the entire length thereof, each of said at least one lateral opening is formed along a distal one-third of said external threads.

16. The system of claim 11, wherein said bonding cement produces an exothermic reaction during curing;

and

wherein each of said at least one lateral opening is formed along a distal one-third of the portion of the surgical anchor disposed within the vertebral body.

17. A system for anchoring a surgical anchor to a vertebral body;

comprising;

a surgical anchor having a proximal end and a distal end, an axial passage extending from said proximal end toward said distal end, at least one lateral opening communicating with said axial passage, and an enlarged proximal end portion engagable within the vertebral body to substantially prevent movement of said proximal end portion relative to the vertebral body, said enlarged proximal end portion of said surgical anchor being formed of a semi-compliant material; and

a supply of bonding cement deliverable through said axial passage, out said at least one lateral opening and into the vertebral body.

18. The system of claim 17, wherein said enlarged proximal end portion of said surgical anchor is formed of a plastic material.