BONE ANCHOR HAVING AN INTEGRATED STRESS ISOLATOR

• US 20130060280A1
• Filed: 09/04/2012
• Published: 03/07/2013
• Est. Priority Date: 09/01/2011
• Status: Active Grant

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Tangherlini, Vincent, Gordon, Norman S., Wolf, Steven
• Granted Patent: US 9,636,101 B2
• Time in Patent Office: Days
• US Class Current: 606/232
• 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 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 2017/0445 cannulated, e.g. with a longitudinal through-hole for passage of an instrument
• CPC Class Codes: A61B 2017/0451 Cams or wedges holding the suture by friction
• CPC Class Codes: A61B 2017/0456 Surface features on the anchor, e.g. ribs increasing friction between the suture and the anchor
• CPC Class Codes: A61B 2090/037 with a frangible part, e.g. by reduced diameter
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• CPC Class Codes: A61F 2002/0817 Structure of the anchor
• 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 2002/0841 Longitudinal channel for insertion tool running through the whole tendon anchor, e.g. for accommodating bone drill, guidewire
• CPC Class Codes: A61F 2002/0847 Mode of fixation of anchor to tendon or ligament
• CPC Class Codes: A61F 2002/0852 Fixation of a loop or U-turn, e.g. eyelets, anchor having multiple holes

Abstract

The present disclosure includes a knotless suture anchoring system for anchoring a suture with respect to a body cavity, including a bone anchor body with at least one rigid anchoring structure to secure the anchor body within the body cavity. The anchor body has a longitudinal bore and cross-pin extending across the bore. A retention member is coupled to the anchor body with a break notch therebetween, which may selectively fracture to separate the body from the retention member. Additionally there is a suture cutout on the retention member and a relief feature positioned along the break notch and approximately diametrically opposed from the suture cutout, the relief feature acting to alter the force dissipation along the break notch during the separation of the retention member from the anchor body.

Claims

1. A knotless suture anchoring system for anchoring a length of suture with respect to a body cavity, comprising:

a bone anchor body comprising at least one rigid anchoring structure to secure the anchor body within the body cavity, the anchor body further comprising a longitudinal bore and a cross-pin extending laterally through the longitudinal bore;

a retention member coupled to the anchor body;

a suture plug for placement in the longitudinal bore to frictionally secure at least one length of suture within the longitudinal bore;

a break notch disposed between the anchor body and the retention member, operable to fracture and facilitate separation of the anchor body from the retention member; and

a suture cutout disposed on the retention member and in communication with the break notch, operable so that a suture may enter the longitudinal bore and exit the longitudinal bore after being passed around the cross-pin; and

a relief feature positioned along the break notch and approximately diametrically opposed from the suture cutout.

2. The knotless suture anchoring system of claim 1 wherein the relief feature comprises a circular hole disposed partially in the bone anchor body and partially in the retention member.

3. The knotless suture anchoring system of claim 1 wherein the retention member comprises one or more lugs to be engaged by a grasping member.

4. The knotless suture anchoring system of claim 1, the break notch forming a relatively low ultimate tensile strength connection between the retention member and bone anchor, the ultimate tensile strength connection interrupted only by the relief feature and the suture cutout.

5. The knotless suture anchoring system of claim 1 wherein the anchor body is constructed from a PEEK material.

6. The knotless suture anchoring system of claim 1, the break notch forming a weakened connection between the bone anchor body and retention member, the weakened connection having a variable cross sectional thickness defined by the longitudinal bore and the break notch and wherein the cross sectional thickness is largest at points that are circumferentially equidistant between the relief feature and suture cutout.

7. The knotless suture anchoring system of claim 1 wherein a suture plug distal tip is operable to apply a load upon the cross-pin and thereby the bone anchor, so as to cause the separation between the bone anchor body and retention member.

8. The knotless suture anchoring system of claim 7 further comprising a suture plug driver rod, slidably disposed within the retention member and in communication with the suture plug, said driver rod operable to place the suture plug within the longitudinal bore and apply an axial force to the plug, so as to cause the separation between the bone anchor body and retention member.

9. The knotless suture anchoring system of claim 1 further comprising an applicator system for inserting and manipulating the bone anchor, comprising;

a grasping member for grasping the retention member and;

a driving rod coaxially located within the grasping member and retention member, operable to load the suture plug within the bone anchor bore.

10. A method of securing soft tissue with respect to a body cavity without knots, comprising:

passing a length of suture through soft tissue so that a portion of the suture is secured in the soft tissue resulting in at least one free end;

providing a bone anchor body comprising a longitudinal bore defining an inner wall, and a cross-pin extending across the longitudinal bore;

passing the free end of the suture through a suture cutout of a retention member coupled to the anchor body, such that the length of suture extends into the longitudinal bore, around the cross-pin, and exits the longitudinal bore through the suture cutout;

inserting the bone anchor body into the body cavity;

applying tension to the suture between the tissue and the bone anchor;

inserting a suture plug into the longitudinal bore to secure the suture to the inner wall of the longitudinal bore;

applying an axial load on the bone anchor body so that the bone anchor body separates from the retention member along a break notch disposed between the bone anchor body and the retention member; and

altering forces generated during separation of the bone anchor body from the retention member by a relief feature that is positioned along the break notch approximately diametrically opposed from the suture cutout.

11. The method of claim 10 wherein the relief feature comprises a circular hole disposed across the bone anchor body and the retention member.

12. The method of claim 10 wherein separation between the retention member and the bone anchor body initiates at the suture cutout only and propagating forces travel circumferentially and dissipate at both sides of the relief feature.

13. The method of claim 10, wherein separation between the retention member and the bone anchor body initiates simultaneously at the suture cutout and the relief feature, and propagating forces travel circumferentially and meet at two locations approximately equidistant between the relief feature and the suture cutout.

14. The method of claim 10, wherein the step of applying is achieved by applying a load to the anchor body via the suture plug.

15. A knotless suture anchoring system for anchoring a length of suture with respect to a body cavity, comprising:

a bone anchor body applicator;

a bone anchor body comprising at least one rigid anchoring structure to secure the bone anchor body within the body cavity, the bone anchor body further comprising a longitudinal bore and a cross-pin extending laterally through the longitudinal bore;

a retention member coupled to the bone anchor body and engaged with the bone anchor body applicator;

a suture plug for placement in the longitudinal bore to frictionally secure a suture to the inner wall of the longitudinal bore;

a suture plug driver rod, in communication with the suture plug and disposed coaxially within the retention member;

a break notch disposed between the bone anchor body and the retention member, operable to fracture and facilitate separation of the bone anchor body from the retention member; and

a suture cutout disposed on the retention member and in communication with the break notch, operable so that a suture may enter and exit the longitudinal bore after being passed around the cross-pin without interrupting the motion of the driver rod; and

a relief feature positioned along the break notch and approximately diametrically opposed from the suture cutout.

16. The knotless suture anchoring system of claim 15, wherein the relief feature comprises a circular hole, disposed partially in the bone anchor and partially in the retention member.

17. The knotless suture anchoring system of claim 15, the break notch forming a relatively low ultimate tensile strength connection between the retention member and bone anchor, the ultimate tensile strength connection continuously disposed circumferentially on the bone anchor body and disrupted only by the relief feature and the suture cutout.

18. The knotless suture anchoring system of claim 17 wherein the connection has a variable cross sectional wall thickness defined by the break notch and the longitudinal bore and wherein the cross sectional thickness is largest at the locations that are circumferentially equidistant between the relief feature and suture cutout.