Bone anchors with thread pattern optimized for attachment to hard and soft bone tissue

• US 9,320,510 B2
• Filed: 01/17/2012
• Issued: 04/26/2016
• Est. Priority Date: 06/22/2004
• Status: Active Grant

• Current Assignee: HS West Investments, LLC
• Original Assignee: HS West Investments, LLC
• Inventors: West, Hugh S. Jr.
• Primary Examiner(s): Nguyen, Tuan V
• Assistant Examiner(s): NGUYEN, TIN DUC
• Application Number:
  US13/351,460
• Publication Number:
  US 20120143250A1
• Time in Patent Office: 1,561 Days
• Field of Search: 606/232, 606/300, 606/301, 606/303, 606/304, 606/305, 606/308, 623/13.14
• US Class Current: 1/1
• 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 17/863 with thread interrupted or changing its form along shank, other than constant taper
• CPC Class Codes: A61B 2017/0414 having a suture-receiving opening, e.g. lateral opening lateral eyelet for attaching suture to needle A61B2017/06019
• CPC Class Codes: A61B 2017/044 with a threaded shaft, e.g. screws

Abstract

Bone anchors useful in rotator cuff repair optimize the thread pattern for engaging different types of bone tissues, including harder cortical bone and softer cancellous bone. Bone anchors may include fine threads for engaging cortical bone and coarse threads for engaging cancellous bone. Threads can be made finer by increasing root diameter and surface angle of the threads. The pitches of the fine and coarse threads are kept the same, which allows fine threads to follow the impression created by coarse threads as the anchor is driven into a bone. Threads that engage cortical bone can be multi-fluted and include a first flute that follows the same thread pattern as coarse threads such that first flute follows the groove created by the coarse threads as the bone anchor is driven into a bone. Bone anchors can have a distal non-threaded stabilizing extension at the distal end.

Claims

1. A bone anchor for use in attaching soft tissue to a bone having hard bone tissue and soft bone tissue, the bone anchor comprising:

an anchor body having a longitudinal axis and a length extending between a proximal end, which forms a proximal face transverse to said longitudinal axis, and a distal end, said anchor body further comprising;

an axial bore with an opening at said proximal face, at least a portion of said axial bore being shaped to form a socket for receiving a driver;

a proximal threaded section having a first flute beginning at a periphery of said proximal face and forming first threads and a second flute beginning at said periphery of said proximal face, having the same pitch as said first flute, and forming second threads between said first threads formed by said first flute; and

a distal threaded section adjacent to and extending distally from said proximal threaded section and including threads formed by a single flute having the same pitch as said first flute,

wherein said proximal threaded section has more threads per unit length than said distal threaded section and constitutes less than half the length of the anchor body,

wherein each of said proximal and distal threaded sections is positioned on said anchor body and has a length such that said proximal threaded section is configured to engage hard bone tissue and said distal threaded section is configured to engage soft bone tissue when said anchor body is fully inserted into a bone.

2. The bone anchor as in claim 1, said first threads of said proximal threaded section having the same thread pattern as said threads of said distal threaded section such that said first flute follows a groove created by said threads of said distal threaded section as the bone anchor is driven into a bone during use.

3. The bone anchor as in claim 1,

said first flute of said proximal threaded section and said single flute of said distal threaded section forming a single continuous flute extending continuously through said proximal and distal threaded sections;

and

said second flute extending to said boundary between said proximal and distal threaded sections.

4. The bone anchor as in claim 1, wherein said proximal threaded section is double-fluted.

5. The bone anchor as in claim 1, said anchor body further comprising a non-threaded section extending between said distal threaded section and said distal end, wherein said non-threaded section is at least about 20% of the combined length of said proximal and distal threaded sections.

6. The bone anchor as in claim 1, further comprising at least one suture attachment site in communication with said axial bore.

7. The bone anchor as in claim 6, wherein said at least one suture attachment site accommodates attachment of at least one looped suture thereto.

8. The bone anchor as in claim 1, wherein said axial bore extends partially through said anchor body and terminates before said distal end so that said anchor body has a closed distal tip.

9. The bone anchor as in claim 1, wherein said proximal threaded section has a major diameter greater than a major diameter of said distal threaded section.

10. The bone anchor as in claim 1, wherein said proximal threaded section has a root diameter greater than a root diameter of said distal threaded section.

11. The bone anchor as in claim 1, wherein said proximal threaded section comprises fine threads and said distal threaded section comprises coarse threads.

12. The bone anchor as in claim 11, wherein said fine threads and said coarse threads have the same pitch such that one of said first or second flutes of said fine threads follows an impression created by said coarse threads as the bone anchor is driven into a bone during use.

13. The bone anchor as in claim 11, wherein said fine threads have a thread angle that is larger than a thread angle of the said coarse threads.

14. The bone anchor as in claim 1, wherein said socket is hexagonal and extends partially through said axial bore.

15. The bone anchor as in claim 1, wherein said anchor body comprises a bioabsorbable material.

16. The bone anchor as in claim 1, wherein said axial bore extends axially through said anchor body from said proximal face to beyond a boundary between said proximal and distal threaded sections.

17. A bone anchor for use in attaching soft tissue to a bone having hard bone tissue and soft bone tissue, the bone anchor comprising:

an anchor body having a longitudinal axis and a length extending between a proximal end, which forms a proximal face transverse to said longitudinal axis, and a distal end, said anchor body further comprising;

an axial bore with an opening at said proximal face, at least a portion of said axial bore being shaped to form a socket for receiving a driver;

a proximal threaded section extending circumferentially to said proximal face and having first threads formed by multiple flutes;

a distal threaded section adjacent to and extending distally from said proximal threaded section and having second threads formed by a single flute with the same pitch as at least one of said multiple flutes of said proximal threaded section; and

a non-threaded section extending between said distal threaded section and said distal end, wherein said non-threaded section is at least about 20% of the combined length of said proximal and distal threaded sections,

wherein said proximal threaded section is multi-fluted so as to have more threads per unit length than said distal threaded section and constitutes less than half the length of the anchor body,

wherein said axial bore extends axially through said anchor body from said proximal end to beyond a boundary between said proximal and distal threaded sections,

wherein each of said proximal and distal threaded sections is positioned on said anchor body and has a length such that said proximal threaded section is configured to engage hard bone tissue and said distal threaded section is configured to engage soft bone tissue when said anchor body is fully inserted into a bone.

18. The bone anchor as in claim 17, wherein said first threads of said proximal threaded section include a first flute having the same thread pattern as said second threads of said distal threaded section such that said first flute follows a groove created by said second threads as the bone anchor is driven into a bone during use.

19. The bone anchor as in claim 17, wherein said anchor body comprises:

a first flute having a single continuous pitch and extending continuously through said proximal and distal threaded sections; and

a second flute having the same pitch as and forming threads between threads formed by said first flute, said second flute extending through said proximal threaded section and terminating at the boundary between said proximal and distal threaded sections.

20. A bone anchor for use in attaching soft tissue to a bone having hard bone tissue and soft bone tissue, the bone anchor comprising:

an anchor body having a longitudinal axis and extending between a proximal end, which forms a proximal face transverse to said longitudinal axis, and a distal end, said anchor body further comprising;

an axial bore with an opening at said proximal face, a portion of said axial bore comprising a socket having a shape configured to receive a correspondingly-shaped driver;

a multi-fluted proximal threaded section beginning at and extending distally from said proximal end;

a single-fluted distal threaded section adjacent to and extending distally from said proximal threaded section;

a first flute having a single continuous pitch and extending from a periphery of said proximal face, through said proximal threaded section, and into said distal threaded section; and

a second flute having the same pitch as said first flute and forming threads between threads formed by said first flute within said proximal threaded section,

wherein said axial bore extends axially through said anchor body from said proximal end to beyond said boundary between said proximal and distal threaded sections,

wherein each of said proximal and distal threaded sections is positioned on said anchor body and said proximal threaded section has a length that is no greater than a length of said distal threaded section such that said proximal threaded section is configured to engage hard bone tissue and said distal threaded section is configured to engage soft bone tissue when said anchor body is fully inserted into a bone.

21. The bone anchor as in claim 20, wherein said proximal threaded section is double-fluted.

22. The bone anchor as in claim 20, said first flute extending continuously through said proximal threaded section and said distal threaded section.

23. The bone anchor as in claim 20, said second flute extending continuously from said periphery of said proximal face to a boundary between said proximal and distal threaded sections.