WO2017213893A1

WO2017213893A1 - Suture anchor assembly for delivery of a therapeutic agent

Info

Publication number: WO2017213893A1
Application number: PCT/US2017/034712
Authority: WO
Inventors: Umasuthan SRIKUMARAN; Geoffrey I. Karasic; George Barnes; Matthew Koski; Mark HOUSMAN
Original assignee: Smith & Nephew, Inc.
Priority date: 2016-06-08
Filing date: 2017-05-26
Publication date: 2017-12-14

Abstract

A suture anchor assembly including a delivery system for a therapeutic agent, such as a bone cement, that is directly integrated into an anchor inserter. The therapeutic agent flows through a shaft of the inserter into a central cannulation of a fenestrated anchor body. Holes in the anchor end of the shaft allow the therapeutic agent to pass through the holes in the shaft and through the apertures in the anchor body into the region of the repair site.

Description

SUTURE ANCHOR ASSEMBLY FOR DELIVERY OF A THERAPEUTIC AGENT

FIELD

The present disclosure relates to surgical fixation devices in general and, more particularly, to fixation devices adapted for delivery of bone cement or other therapeutic agents to a repair site.

BACKROUND

Surgical procedures using sutures and suture anchors have been used in soft tissue repair, for example, to secure soft tissue to bone. Current suture anchors provide fixation to bone via threads, friction-creating features, or expanding features that interface with the surrounding bone. In poor quality bone, however, the fixation of suture anchors can be compromised, causing intraoperative challenges and inefficiencies such as anchor pullout, prolonged operating time, wasted product, administration of additional anesthesia and/or the inability to complete the soft tissue repair. Postoperatively, inadequate anchor fixation can lead to various problems, including cartilage damage, patient pain and discomfort, the need for further medical intervention, and the incomplete healing of the repair. In the event of an anchor migrating or pulling out completely from bone, an alternative larger anchor would need to be used, or two anchors would be inserted in close proximity.

SUMMARY

Disclosed herein is a suture anchor assembly including a delivery system which can deliver bone cement or other therapeutic agents into the central cannulation of the anchor that integrates with the surrounding bone architecture and thereby improves anchor fixation and/or facilitates healing. Holes in the anchor end of the shaft allow the bone cement or other therapeutic agent to pass through apertures in the anchor body into the region of the repair site. Thus, the soft tissue repair process is made simpler and quicker, and results in less waste than in current systems. Additionally, the suture anchor assembly of this disclosure could be used alone or in combination with other therapeutic agents to be delivered to the repair site. Further examples of the suture anchor assembly of this disclosure may include one or more of the following, in any suitable combination.

In examples, the suture anchor assembly of this disclosure includes an anchor body having a proximal end, a distal end, and a cannulation extending along a longitudinal axis therebetween. The cannulation is in communication with a region exterior to the anchor body through at least one aperture in a surface of the anchor body. The assembly also includes an inserter having a handle and an elongated shaft. A distal end of the shaft is disposed within the cannulation of the anchor body. A lumen extends through the shaft along the longitudinal axis and defines at least one opening, which may be a hole, at the distal end of the shaft. The assembly further includes a delivery system attached to the handle. The delivery system defines an internal volume in direct communication with the lumen of the shaft when the delivery system is attached to the handle. Actuation of the delivery system causes a therapeutic agent contained in the internal volume of the delivery system to be delivered through the lumen of the shaft into the region exterior to the anchor body through the at least one aperture in the surface of the anchor body.

In further examples, the anchor body is in the form of an open helical coil. The at least one aperture in the surface of the anchor body is defined by a space between turns of screw threads of the open helical coil. The anchor body is made from a material selected to compliment the therapeutic agent. A distal end of the anchor body has a suture bridge extending a partial length of the anchor body, and at least one rib extending from the suture bridge to the proximal end of the anchor body. The anchor body is located on the shaft of the inserter such that a proximal end of the suture bridge is housed within a slot of the inserter and the at least one rib of the anchor body is housed within grooves of the inserter.

In still further examples, the delivery system is a manual injection syringe. The therapeutic agent is one of bone cement, platelet rich plasma (PRP), anti -inflammatories, pain relievers, calcium phosphate-based bone graft substitute, autologous stem cells, collagen- based scaffold or other bioscaffold material, or combinations of the above. The handle includes a grip and a connector coupled to the grip. The connector includes a first channel in direct communication with a second channel of the grip. A proximal end of the shaft extends extends through the first channel of the connector and the second channel of the grip. The delivery system is attached to the handle by a delivery system interface, which may be a luer lock interface.

Examples of the method of delivering a therapeutic agent to a repair site of this disclosure include: using an inserter, inserting an anchor body as described above into a repair site; and actuating a delivery system attached to the handle of the inserter to deliver a therapeutic agent contained within the internal volume of the delivery system through at least one aperture in the surface of the anchor body into the repair site. In examples, the delivery system is a manual injection syringe. In examples, the therapeutic agent is bone cement and, after the bone cement has been delivered into the repair site, a mean pull-out strength of the anchor body is between about 389N and about 690N. In other examples, the therapeutic agent is selected from a group comprising platelet rich plasma (PRP), anti-inflammatories, pain relievers, calcium phosphate-based bone graft substitute, autologous stem cells, collagen- based scaffold or other bioscaffold material, or combinations thereof.

These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of aspects as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be more fully understood by reference to the detailed description, in conjunction with the following figures, wherein:

FIG. 1 is an exemplary suture anchor assembly of this disclosure;

FIGS. 2 and 3 are examples of anchor bodies of the suture anchor assembly of FIG. 1; FIG. 4 is a detail of the distal end of the shaft of the inserter of the suture anchor assembly of FIG. 1;

FIG. 5 is a detail of the distal end of the shaft of FIG. 4 inserted into the anchor body of FIG. 3;

FIG. 6 is a cross-sectional view of the handle assembly of the suture anchor assembly of FIG. 1; and

FIGS. 7A-D illustrate an exemplary method of using the suture anchor assembly of

FIG. 1. DETAILED DESCRIPTION OF THE EMBODIMENTS In the description that follows, like components have been given the same reference numerals, regardless of whether they are shown in different examples. To illustrate example(s) in a clear and concise manner, the drawings may not necessarily be to scale and certain features may be shown in somewhat schematic form. Features that are described and/or illustrated with respect to one example may be used in the same way or in a similar way in one or more other examples and/or in combination with or instead of the features of the other examples.

As used in the specification and claims, for the purposes of describing and defining the invention, the terms "about" and "substantially" are used represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms "about" and "substantially" are also used herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. "Comprise,"

"include," and/or plural forms of each are open ended and include the listed parts and can include additional parts that are not listed. "And/or" is open-ended and includes one or more of the listed parts and combinations of the listed parts.

Referring now to FIG. 1, an exemplary suture anchor assembly 100 of the present disclosure is illustrated. The suture anchor assembly 100 generally comprises an anchor body 102 distally located on an inserter 200, and a delivery system 300 attached to the proximal end of the inserter 200. The delivery system 300 is configured to deliver bone cement 500 or other therapeutic agents through the anchor body 102 into a surrounding repair site, as further described below. Examples of such therapeutic agents may include platelet rich plasma (PRP), anti-inflammatories, pain relievers, calcium phosphate-based bone graft substitute, autologous stem cells, collagen-based scaffold or other bioscaffold material, or combinations of the above. Examples of the delivery system 300 may include a manual linear syringe as shown in FIG. 1. However, other types of delivery systems, such as power syringes or screw style syringes, are also contemplated by this disclosure.

In FIG. 1 the anchor body 102 is illustrated as an open helical coil anchor, as described in more detail below. While open helical coil anchors are particularly suited to the suture anchor assembly 100 of this disclosure, any type of cannulated, fenestrated anchor body 102 can be used. The inserter 200 generally includes a hollow shaft 201 fixedly attached to a handle assembly 210. The handle assembly 210 can be made from plastic or other suitable non-metal and metal materials. The shape and size of handle assembly 210 may be any shape and size necessary to facilitate insertion of the anchor body 102 into bone. The shaft 201 is preferably made from a biocompatible metal material, such as stainless steel. However, other metal and non-metal materials that would withstand the forces applied during surgery are contemplated by this disclosure. The length and diameter of the shaft 201 may also vary depending on the type of surgical repair.

FIG. 2 is a detailed illustration of an exemplary anchor body 102 of this disclosure. However, it is important to note that the anchor body 102 of FIG. 2 is only one of many examples of an anchor body 102 that can be used with the suture anchor assembly 100 of this disclosure. The anchor body 102 includes a proximal end 101 and a distal end 107. The distal end 107 also includes a suture bridge 105 that extends a partial length of the anchor body 102. The suture bridge 105 includes a proximal end 105a and a distal end 105b. The distal end 105b of the suture bridge 105 has a thickness greater than a thickness of the proximal end 105a of the suture bridge 105. In examples, the distal end 105b of the suture bridge 105 has a concave shape. A suture 110 or other flexible member can be housed within the anchor body 102 such that the suture 110 extends around the distal end 105b of the bridge 105 and the suture ends 112, 114 exit the proximal end 101 of the anchor body 102.

As discussed above, the anchor body 102 of FIG. 2 is an open helical coil anchor.

That is, a majority of the anchor body 102 includes screw threads 103 in the form of an open helical coil, i.e. a connected series of continuous regularly spaced turns of screw threads 103 extending in a helical or spiral form substantially from the distal end 107 to the proximal end 101 of the anchor body 102. Apertures 104 in the surface of the anchor body 102 are defined by the spaces in between the turns of the screw threads 103. In addition, at least one longitudinally-extending rib 106 extends from the suture bridge 105 and along the interior of the screw threads 103, the purpose of which will be further described below. In the example of FIG. 2, there are two longitudinally extending ribs 106. However, more or fewer than two ribs 106 are contemplated by this disclosure. In the anchor body 102 of FIG. 2, the screw threads 103 cover the proximal end 105a of the suture bridge 105. Another example of an anchor body 402 of this disclosure is shown in FIG. 3. In the anchor body 402 of FIG. 3, the screw threads 403 start at the proximal end 405a of the suture bridge 405 but do not cover the proximal end 405a of the suture bridge 405. In this example, the anchor body 402 also includes webbing 408 between the most proximal screw thread 403a and the second most proximal screw thread 403b, as well between the most distal screw thread 403c and the second most distal screw thread 403d. The webbing 408 gives the anchor body 402 torsion and compression strength. Other non-limiting examples of open helical coil anchor bodies 102, 402 may be found in U.S. Publication No. 2013/0178901 to Smith & Nephew, Inc., incorporated by reference herein in its entirety.

The anchor body 102, 402 can be made from any combination of polymers, metal, bioabsorbable, or biocomposite material, which may be further selected to compliment the therapeutic agent 500. For example, the anchor body 102, 402 may be partially or entirely formed from a formulation of poly(lactic-co-glycolic) acid (PLGA), β-Tricalcium phosphate (β-TCP) and calcium sulfate, poly-L-lactic acid - hydroxyapatite (PLLA-HA), poly-D-lactide (PDLA), polymers such as polyether ether ketone (PEEK), or variants thereof. Biocomposite examples made from a combination of PLGA, β-TCP, and calcium sulfate are absorbable by the body, which is beneficial to natural healing. An example formulation of PLGA, β-TCP, and calcium sulfate is described in U.S. Patent No. 8,545,866 to Smith & Nephew, Inc., incorporated by reference herein in its entirety. Copolymers of polyglycolic acid (PGA) and polytrimethylene carbonate (TMC) are further examples of a bioabsorbable material. Other commonly used materials that are capable of providing the strength needed to set the anchor body 102, 402 into bone and to hold the tissue graft in position while bone-to-tissue in-growth occurs are also contemplated by this disclosure.

Turning now to FIG. 4, a detail of the distal end of the shaft 201 of the inserter 200 is shown. The distal end of the shaft 201 includes a slot 202 with grooves 203 extending proximally from the slot 202 on each side of the shaft 201. The shaft 201 also includes an internal cannulation 204 for passage of suture ends 112, 114 (FIG. 2). One or more openings 205 may extend through a surface of the shaft 201 so as to be in communication with the internal cannulation 204. The openings 205 and the open end of the cannulation 204 are configured for the passage of a bone cement 500 or other therapeutic agent, as further described below. The openings 205 may be in the form of holes, perforations, meshes or other configurations depending upon the material to be used.

In FIG. 5, the anchor body (shown here for illustrative purposes as anchor body 402) is located on the shaft 201 of the inserter 200 such that the proximal end 405a of the suture bridge 405 is housed within the slot 202 of the inserter 200 and the ribs 406 of the anchor body 402 are housed within the grooves 203 of the inserter 200. When the anchor body 402 is located on the inserter 200, the openings 205 of the inserter 200 are aligned with the apertures 404 between the screw threads 403 of the anchor body 402 to allow the passage of a bone cement or other therapeutic agent into a repair site, as further described below.

Turning now to FIG. 6, a cross-section of the handle assembly 210 of the inserter 200 is shown. The handle assembly 210 generally includes a grip 206 configured to be held by a user, and a connector 208 coupled to the grip 206. The connector 208 has a first channel 212a in direct communication with a second channel 212b of the grip 206. The proximal end of the grip 206 is configured to accept a delivery system interface 214, such as a luer lock syringe interface. As shown in FIG. 6, the proximal end of the shaft 201 is disposed within the first channel 212a and the second channel 212b such that the cannulation 204 of the shaft 201 is in direct communication with the internal volume 216 of the delivery system 300 when the delivery system 300 is attached to the inserter 200.

FIGS. 7A-D illustrate a method of using the suture anchor assembly, for example the suture anchor assembly 100 of FIG. 1. In the examples shown in FIG. 7A-D, the anchor body 102 may be driven into bone 600 using the inserter 200 of FIG. 1 with the delivery system 300 attached. In other examples, the anchor body 102 may be driven into bone 600 using a separate inserter (not shown) and the shaft 201 of the inserter 200 may be inserted into the anchor 102 after the separate inserter has been removed. In either example, once the anchor body 102 has been driven into a repair site 602 in a bone 600 (FIG. 7 A), upon activation of the delivery system 300, the bone cement 500 or other therapeutic agent contained in the delivery system 300 flows through the shaft 201 which is in direct communication with the delivery system 300 (FIG. 7B). Notably, the shaft 201 is sealed by pressure so that it will not leak. The delivery system 300 may then be removed from the shaft 201 and a device, such as an obturator 604, may optionally be inserted into the shaft 201 to urge the bone cement 500 or other therapeutic agent distally through the shaft 201 toward the repair site 602 (FIG. 7C). The bone cement 500 or other therapeutic agent then exits through the distal end of the shaft 201 and through the fenestrated anchor body 402 into the surrounding repair site 602 (FIG. 7D). Thus, the suture anchor assembly 100 of this disclosure advantageously allows the user to precisely place the bone cement 500 at the repair site 602 surrounding the anchor body 402.

Example

Methods: Six fresh-frozen matched pairs of the upper extremities of a shoulder joint were screened by DEXA. A T-score of < -2.5 at the distal radius was the inclusion criteria for this method. One side from each pair was randomized to undergo standard anchor fixation, with the contralateral side to undergo the augmented anchor fixation. Augmented anchor fixation consisted of injecting of cement through a cannulated anchor. Specimens were mounted at a 20° angle to the horizon and suture anchors were pulled vertically upwards at an increasing axial load measured using an MTSTS. Constructs underwent cyclic loading until failure, with applied load increasing in a stepwise fashion.

Results: The mean [95% confidence interval] pullout for augmented anchors was 539.2 N [389N-690N], and 202.5 N [100N-305N] for standard anchors. The difference s between the pullout strengths were statistically significant (p<0.01).

Conclusion: The results demonstrate significantly increased pullout strength for augmented anchors relative to non-augmented anchors in osteoporotic bone. The

augmentation technique demonstrates a 166% improvement in mean pullout strength, while prior studies to evaluate augmented anchors demonstrated a 46.9% improvement in mean pullout strength. The method of this disclosure resulted in greater proportional increase in pullout strength secondary to interdigitation of cement with trabecular bone, and overall increased contact area at a hybrid bone-anchor-cement interface.

In examples, not shown, the suture anchor assembly 100 of FIG. 1 could also be used to aspirate fluid, such as bone marrow, into the delivery system 300. For example, the anchor body 102 could be delivered into bone, such as a humeral head, using the inserter 200. The delivery system 300 could then be used in reverse to aspirate the bone marrow through the anchor body 102 and through the shaft 201 into the delivery system 300. The aspirate could then be used whole or spun down to extract various elements, which could then be delivered by the suture anchor assembly 100 to repaired tissue, such as a tendon, to facilitate healing. While this disclosure has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. Such variations are intended to be covered by the scope of this present application. As such, the foregoing description of examples of the present application is not intended to be limiting, the full scope rather being conveyed by the appended claims.

Claims

CLAIMS What is claimed is:

1. An assembly for delivering a therapeutic agent to a repair site, the assembly comprising:

an anchor body having a proximal end, a distal end, and a cannulation extending along a longitudinal axis therebetween, the cannulation in communication with a region exterior to the anchor body through at least one aperture in a surface of the anchor body; and

an inserter comprising a handle and an elongated shaft, a distal end of the shaft disposed within the cannulation of the anchor body, a lumen extending through the shaft along the longitudinal axis and defining at least one opening at the distal end of the shaft; and a delivery system attached to the handle, the delivery system defining an internal volume in direct communication with the lumen of the shaft when the delivery system is attached to the handle;

wherein actuation of the delivery system causes the therapeutic agent contained in the internal volume of the delivery system to be delivered through the lumen of the shaft into the region exterior to the anchor body through the at least one aperture in the surface of the anchor body.

2. The assembly of claim 1, wherein the anchor body is in the form of an open helical coil.

3. The assembly of claim 2, wherein the at least one aperture in the surface of the anchor body is defined by a space between turns of screw threads of the open helical coil.

4. The assembly of claim 1, wherein the anchor body comprises a material selected to compliment the therapeutic agent.

5. The assembly of claim 1, wherein a distal end of the anchor body comprises a suture bridge extending a partial length of the anchor body, and at least one rib extending from the suture bridge to the proximal end of the anchor body.

6. The assembly of claim 5, wherein the anchor body is located on the shaft of the inserter such that a proximal end of the suture bridge is housed within a slot of the inserter and the at least one rib of the anchor body is housed within grooves of the inserter.

7. The assembly of claim 1, wherein the delivery system is a manual injection syringe.

8. The assembly of claim 1, wherein the therapeutic agent is bone cement.

9. The assembly of claim 1, wherein the therapeutic agent is selected from a group comprising platelet rich plasma (PRP), anti-inflammatories, pain relievers, calcium

phosphate-based bone graft substitute, autologous stem cells, collagen-based scaffold or other bioscaffold material, or combinations thereof.

10. The assembly of claim 1, wherein the at least one opening is a plurality of holes.

11. The assembly of claim 1, wherein the handle comprises a grip and a connector coupled to the grip.

12. The assembly of claim 1 1, wherein the connector comprises a first channel in direct communication with a second channel of the grip.

13. The assembly of claim 12, wherein a proximal end of the shaft extends through the first channel of the connector and the second channel of the grip.

14. The assembly of claim 1, wherein the delivery system is attached to the handle by a delivery system interface.

15. The assembly of claim 14, wherein the delivery system interface comprises a luer lock interface.

16. A method of delivering a therapeutic agent to a repair site in a surgical repair, the method comprising:

using an inserter, inserting an anchor body into a repair site, the anchor body having a proximal end, a distal end, and a cannulation extending along a longitudinal axis

therebetween, the cannulation in communication with a region exterior to the anchor body through at least one aperture in a surface of the anchor body, a distal end of a shaft of the inserter disposed within the cannulation of the anchor body, the distal end of the shaft comprising at least one opening defined by a lumen extending through the shaft in direct communication with an internal volume of a delivery system; and

actuating the delivery system to deliver the therapeutic agent contained within the internal volume through the at least one aperture in the surface of the anchor body into the repair site.

17. The method of claim 16, wherein the anchor body is in the form of an open helical coil and the at least one aperture in the surface of the anchor body is defined by a space between turns of screw threads of the open helical coil.

18. The method of claim 16, wherein the delivery system is a manual injection syringe.

19. The method of claim 16, wherein the therapeutic agent is bone cement.

20. The method of claim 19, wherein, after the bone cement has been delivered into the repair site, a mean pull-out strength of the anchor body is between about 389N and about 690N.

21. The method of claim 16, wherein the therapeutic agent is selected from a group comprising platelet rich plasma (PRP), anti-inflammatories, pain relievers, calcium