Distal tip two piece external expansion anchor

Patent metadata

Field	Value
Publication number	US-10582920-B2
Application number	US-201414903686-A
Country	US
Kind code	B2
Filing date	Mar 6, 2014
Priority date	Jul 10, 2013
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

Examples of a suture anchor ( 100 ) having a non-expandable body ( 105 ) and expendable cap ( 110 ) are described herein. In response to an axial insertion force that brings the non-expandable body and expendable cap together inside a bone hole, the expendable cap expands radially. This creates a radial force of expansion that advantageously augments an interference fit between the suture anchor and bone hole, which leads to higher fixation strength. Other examples include retention features that inhibit the expendable cap from returning back into its unexpanded state. This advantageously maintains the radial force of expansion against the surrounding pressure of the walls of the bone hole pressing back on the suture.

First claim

The invention claimed is:

1. A suture anchor comprising:
a non-expandable body comprising:
a distal end having a first portion and a second portion;
a proximal end configured to engage a suture anchor insertion instrument;
an internal cannulation extending from the distal end to the proximal end; and
a plurality of projections extending, radially, from an outer surface between the distal end and proximal end, the plurality of projections configured to compress into bone;

an expandable cap having a distal terminal surface comprising a first aperture and a second aperture, the expandable cap defining a cavity configured to engage the distal end of the non-expandable body, the cavity having a diameter larger than the first portion and smaller than the second portion that, when in a deployed position, allows the expandable cap to expand radially outward and compress into the bone during engagement of the distal end of the non-expandable body and the expandable cap; and
a suture extending through the first and second apertures and from the cavity of the expandable cap, the suture being slidably received within the cannulation of the non-expandable body such that an eyelet portion of the suture extends from a proximal terminus of the cannulation external to the non-expandable body;
wherein a distal end of the non-expandable body includes a ramp portion formed at an angle to a longitudinal axis of the non-expandable body, the geometry of the ramp portion and at least one of the plurality of projections being a truncated conical section comprising a distal first diameter and a proximal second diameter larger than the first diameter;
wherein the expandable cap is configured such that a proximal force exerted on the expandable cap is effective to pull the distal end of the non-expandable body into the cavity of the expandable cap; and
wherein, in the deployed position, the cavity of the expandable cap is configured to receive only the distal end of the non-expandable body such that the proximal end of the non-expandable body extends external to the cavity whereby at least one of the plurality of projections is external to the cavity and proximal to the expandable cap, and a distal terminus of the non-expandable body is disposed within the cavity.

2. The suture anchor of claim 1 wherein the first portion of the distal end does not engage a surface of the cavity; and the wherein the second portion of the distal end engages the surface of the cavity.

3. The suture anchor of claim 1 wherein the proximal end comprises one of a protrusion or recess configured to engage a complementary recess or protrusion, respectively, of a suture anchor insertion instrument.

4. The suture of claim 1 wherein the plurality of projections comprise a plurality of annular ribs each extending around an entire circumference of the non-expandable body.

5. The suture anchor of claim 1 wherein the cavity has a shape complementary to the distal end of the non-expandable body.

6. The suture anchor of claim 1 wherein the terminal surface is adjacent the cavity and defines the first aperture, the second aperture, and a bridge separating the first aperture and the second aperture; and wherein a portion of the suture extends around the bridge such that the portion of the suture is distal to the expandable cap, and a first free end and a second free of the suture are routed through the first aperture and second aperture, respectively, and through a through hole toward the proximal end of the non-expandable body.

7. The suture anchor of claim 6 wherein the first free end and the second free are coupled together.

8. The suture anchor of claim 1 wherein the expandable cap comprises a distal end and a proximal end; and further comprises at least one expansion slot formed in the proximal end of the expandable cap.

9. The suture anchor of claim 8 wherein the at least one expansion slot is aligned with the axis of the non-expandable body.

10. The suture anchor of claim 1 wherein the distal end of the non-expandable body further comprises a locking insert tab; and wherein the expandable cap further comprises a holding insert tab configured to engage the locking insert tab such that when the locking insert tab and holding insert tab are engaged, the expandable cap and the non-expandable body are locked together.

11. The suture anchor of claim 1 wherein the distal end of the non-expandable body comprises an annular protrusion; and wherein the expandable cap comprises an annular groove configured to engage the annular protrusion such that when the annular groove and annular protrusion are engaged, the expandable cap and the non-expandable body are locked together.

12. The suture anchor of claim 1 further comprising a post extending, axially, from the cavity of the expandable cap; and wherein the cannulation is configured to receive the post and align the non-expandable body and the expandable cap.

13. The suture anchor of claim 1 further comprising at least one protrusion formed on the outer surface of the non-expandable body at the distal end; and wherein the at least one expansion slot is configured to receive the at least one protrusion and align the non-expandable body and the expandable cap.

14. The suture anchor of claim 1 wherein the non-expandable body is made from a first material; and wherein the expandable cap is made from a second material more flexible than the first material.

15. The suture anchor of claim 1 wherein the non-expandable body has a diameter between 1 mm and 3 mm.

16. The suture anchor of claim 1 wherein the non-expandable body comprises a material selected from a formulation of poly(lactic-co-glycolic) acid (PLGA), ß-Tricalcium phosphate (ß-TCP) and calcium sulfate, poly-L-lactic acid-hydroxyapatite (PLLA-HA), polyether ether ketone (PEEK) or variants thereof.

17. The suture anchor of claim 1 wherein the cavity extends through the cap for less than an entire length of the cap.

18. The suture anchor of claim 1 wherein the suture is coupled to the expandable cap such that a proximal force exerted on the suture is effective to pull the expandable cap into the engagement with the distal end of the non-expandable body.

Assignees

• Smith & Nephew Inc

Inventors

• Lunn Richard M
• Young Timothy
• Koski Matthew Edwin
• Slusarz John
• Duhamel Paul R
• Fan wei li
• Astorino Steven

Classifications

• A61B2017/0412

  having anchoring barbs or pins extending outwardly from suture anchor body · CPC title

• A61B17/0401 Primary

  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 title

• A61B2017/0414

  having a suture-receiving opening, e.g. lateral opening · CPC title

• A61B2017/0424

  the separate member staying in the anchor after placement · CPC title

• A61B2017/0445

  cannulated, e.g. with a longitudinal through-hole for passage of an instrument · CPC title