Open helical organic tissue anchor having recessible head and method of making the organic tissue anchor

• US 20030229350A1
• Filed: 05/28/2003
• Published: 12/11/2003
• Est. Priority Date: 08/22/1995
• Status: Active Grant

• Current Assignee: OrthoHelix Surgical Designs, Inc. (Stryker Corporation)
• Original Assignee: OrthoHelix Surgical Designs, Inc. (Stryker Corporation)
• Inventors: Kay, David B.
• Granted Patent: US 7,189,251 B2
• Time in Patent Office: Days
• US Class Current: 606/72
• CPC Class Codes: A61B 17/0401 Suture anchors, buttons or pledgets, i.e. means for attaching sutures to bone, cartilage or soft tissue; Instruments for applying or removing suture anchors A61B17/0642 takes precedence; fixation devices for tendons or ligaments A61F2/0811
• CPC Class Codes: A61B 17/0642 for bones, e.g. for osteosynthesis or connecting tendon to bone
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 17/869 characterised by an open form, e.g. wire helix
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61B 2017/0409 Instruments for applying suture anchors
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening
• CPC Class Codes: A61B 2017/0441 the shaft being a rigid coil or spiral
• CPC Class Codes: A61B 2017/0649 Coils or spirals
• CPC Class Codes: A61F 2/0805 Implements for inserting tendons or ligaments
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• CPC Class Codes: A61F 2002/0829 without deformation of anchor parts, e.g. fixation screws on bone surface, extending barbs, cams, butterflies, spring-loaded pins
• CPC Class Codes: A61F 2002/0858 Fixation of tendon or ligament between anchor and bone, e.g. interference screws, wedges
• CPC Class Codes: A61F 2002/0864 Fixation of tendon or ligament between anchor elements, e.g. by additional screws in the anchor, anchor crimped around tendon
• CPC Class Codes: A61F 2002/0888 Anchor in or on a blind hole or on the bone surface without formation of a tunnel
• CPC Class Codes: Y10S 606/908 Bioabsorbable material

Abstract

The invention relates to a tissue anchor which is an open helix of biocompatible material having a slope of from 0.5 to 10 turns per centimeter, a length from 3 to 75 millimeters, a diameter of from 1.5 to 11 millimeters, and an aspect ratio of from about 3 to about 5 to 1. The anchor can have a head which is capable of securing or clamping tissue together, such as holding a suture to secure a ligament or tendon to bone. The anchor can also have a head which causes an inward, compressive loading for use in fastening bone to bone, orthopedic plates to bone, or cartilage to bone. The head may be an integral member and may include a self-reinforcing wedge which joins the helix to the head. Further, the elongate member, or filament that forms the helix may have a tapering diameter along its length.

Claims

1. A tissue anchor which can be implanted using a insertion tool and comprising a rigid biocompatible elongate member which forms an open, helical structure having a length from about 3 millimeters to about 75 millimeters, an outer diameter of from about 1.5 to about 15 millimeters, a slope from about 0.5 to about 10 turns per centimeter and having at a first end, an insertion tip adjacent an insertion end, and at a second end, a solid attachment head having substantially the same outer diameter as the helical structure, and having an internal recess to receive the insertion tool.

2. A tissue anchor as set forth in claim 1 wherein the helical structure has a longitudinal axis and the internal recess is a hexagon along the longitudinal axis.

3. A tissue anchor as set forth in claim 2 wherein the head further includes a slot substantially transverse to the direction of the longitudinal axis.

4. A tissue anchor as set forth in claim 3 wherein the head has a cylindrical body integral to the helical member.

8. A tissue anchor as set forth in claim 1, wherein the elongated member tapers to decrease in diameter toward the insertion end.

9. A tissue anchor as set forth in claim 8 wherein the elongate member has a diameter value at the insertion end and the increase in the taper is from about 5 to about 100% of the diameter value at the insertion end.

10. A tissue anchor as set forth in claim 9 wherein the increase in taper is from about 10 to about 50% of the diameter value

5. A tissue anchor wherein the head further includes an opening in the direction of the longitudinal axis.

6. A tissue anchor as set forth in claim 5 wherein the helical structure has from three to sixteen complete turns.

7. A tissue anchor as set forth in claim 6 wherein the elongate member has a thread shaped cross-section.

11. A method of forming a tissue anchor which can be implanted using an insertion tool and comprising the steps of forming a blank member of a biocompatible material having a external thread which forms a helical structure having a length from about 3 millimeters to about 75 millimeters, an outer diameter of from about 1.5 to about 15 millimeters, a slope from about 0.5 to about 10 turns per centimeter and having at a first end, an insertion tip, and said blank having at a second end, a cylindrical shaped attachment head having an outer diameter which is substantially the same outer diameter as the helical structure, and having an internal recess to receive the insertion tool, and subsequently forming a bore in the blank so that the helical structure is open.

12. A method as set forth in claim 11 wherein said blank is formed by injection molding or on a screw machine.

13. A method as set forth in claim 12, wherein the bore in the helical structure has an internal diameter which tapers to a smaller diameter where the attachment head joins the helical structure.

14. A method as set forth in claim 13, wherein said bore is formed by reaming the blank.

15. A method as set forth in claim 14 wherein said blank is reaming using a cortical auger.

16. A method as set forth in claim 11, wherein said attachment head has a cylindrical body.

17. A method as set forth in claim 11, wherein said attachment head further includes a portion having an enlarged outer diameter.