WO2018075495A1

WO2018075495A1 - Tissue fixation devices and methods

Info

Publication number: WO2018075495A1
Application number: PCT/US2017/056952
Authority: WO
Inventors: Stephen Santangelo; Roman Gutierrez; Kirsten H. AARSVOLD; Jennifer Ng; Siraaj DHRU
Original assignee: Smith and Nephew Inc
Current assignee: Smith and Nephew Inc
Priority date: 2016-10-20
Filing date: 2017-10-17
Publication date: 2018-04-26
Anticipated expiration: 2019-04-20

Abstract

Tissue fixation devices (100) and methods for securing soft tissue to bone during ACL and/or PCL reconstruction. Tissue fixation is accomplished with pound-in type anchors which feature longitudinal ribs (114) or splines rather than circumferential threads, as in interference screws. Instead of using a screwdriver to twist and insert the anchor, the anchors (102) can be pulled into the bone in an inside-out approach using a slap hammer attached to an impacting device (120).

Description

TISSUE FIXATION DEVICES AND METHODS FIELD

This disclosure is directed to devices and methods for securing soft tissue to bone and, more particularly, for securing soft tissue to bone in anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction.

BACKGROUND

An increasing number of surgical techniques are now performed arthroscopically. One type of arthroscopic procedure reconstructs the ACL in the knee. (The PCL, although larger and stronger than the ACL, can also be torn). When the ACL has ruptured and is non- repairable, it can be replaced using a substitute graft harvested from the patient or from a donor. The substitute ACL graft may be a portion of a patellar tendon or a semitendinosus and/or gracilis tendon graft. Alternatively, an artificial graft formed from synthetic materials or from a combination of artificial and natural materials may be used and is sometimes referred to as a ligament augmentation device. The term "tissue graft" is used herein to encompass all of these tissue replacements.

In an ACL procedure, the tissue graft is typically implanted by securing one end of the tissue graft through a passage formed in the femur, and the other end of the graft through a passage formed in the tibia. In the femur, the passage is either drilled from the exterior cortex into the knee joint (an "outside-in" procedure) or drilled from the inside of the knee joint at the femoral ACL footprint to a certain depth in bone (an "inside-out" procedure), which creates a socket for the tissue graft to fit into. Generally, a fixation device, such as an interference screw, is used to affix each end of the tissue graft to the bone inside the femoral and tibial passages. However, while interference screws provide adequate fixation, they can cause graft damage (such as twisting and cutting) which occurs as a result of the screw threads winding against the tissue graft during insertion.

SUMMARY

Described herein are tissue fixation devices and methods for securing soft tissue to bone during ACL and/or PCL reconstruction. In this disclosure, tissue fixation is accomplished with pound-in type anchors which feature longitudinal ribs or splines rather than circumferential threads, as in interference screws. Instead of using a screwdriver to twist and insert the anchor, the anchors can be pulled into the bone in an inside-out approach using a slap hammer attached to an impacting device. Advantageously, not only does the use of pound-in anchors avoid graft damage during insertion, but the inside-out approach allows for the development of novel surgical techniques.

Further examples of the tissue fixation devices and methods of this disclosure may include one or more of the following, in any suitable combination.

In examples of the disclosure, the tissue fixation device includes an anchor having a generally elongated anchor body with a proximal end, a tapered distal end, and a cannulation extending along a longitudinal axis therebetween. The cannulation has a proximal portion and a distal portion, with a diameter of the proximal portion selected to be larger than a diameter of the distal portion. The tissue fixation device also includes an impact member, a distal end of which is attached to a flexible element. The impact member is sized and shaped to be slidably received within at least the proximal portion of the cannulation of the anchor body when the flexible element is inserted through the cannulation such that it exits the distal end of the anchor body. When a repeated force is applied to the flexible element, the force causes the impact member to urge the anchor body into a bone hole formed in bone.

In further examples, the tissue fixation device includes a shelf defined by the transition between the diameter of the proximal portion and the diameter of the distal portion. The anchor body has surface features for improving fixation strength of the anchor body within a bone hole or tunnel, which may be longitudinal ribs. The distal portion of the cannulation is tapered, and the proximal portion of the cannulation has a circular or a cross-shaped cross- section. A distal end of the impact member is tapered. The impact member has a proximal stop having a diameter selected to be larger than the diameter of the proximal portion of the cannulation.

Examples of the method of tissue fixation of this disclosure include: 1) attaching a first end of a tissue graft to an anchor as described above; 2) passing a flexible element through the cannulation of the anchor body such that a distal end of the flexible element exits the distal end of the anchor, the proximal end of the flexible element attached to an impact member as described above; 3) attaching a source of distal force to a distal end of the flexible element; and 4) repeatedly applying the distal force to the flexible element such that the impact member repeatedly strikes a portion of the anchor body, the force causing the anchor body and the tissue graft to move distally together into a first bone hole formed in a first bone.

In further examples, the flexible element is a guide wire. The impact member repeatedly strikes a shelf defined by the transition between the diameter of the proximal portion and the diameter of the distal portion of the cannulation of the anchor body. The impact member has a proximal stop with a diameter selected to be larger than a diameter of the proximal portion of the cannulation, and the proximal stop repeatedly strikes a proximal face of the anchor body. The method further includes forming the first bone hole in the first bone and/or forming a second bone hole in a second bone adjacent to the first bone. The tissue graft is secured to the first bone hole and to the second bone hole by interference fixation or by suspension fixation.

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 A illustrates an anchor body of an exemplary tissue fixation device of this disclosure for use in an ACL reconstruction;

FIGS. IB and 1C are cross-sectional views of the anchor body of FIG. 1A;

FIG. 2 is a partially assembled view of the tissue fixation device of this disclosure with the anchor body of FIG. 1 A;

FIGS. 3 A and 3B depict an anchor body of an alternative tissue fixation device of this disclosure;

FIG. 3C is a cross-sectional view of the anchor body of FIGS. 3 A and 3B;

FIG. 4 is a partially assembled view of the tissue fixation device of this disclosure with the anchor body of FIGS. 3A-C; FIGS. 5A-6B show alternative examples of the surface features of the anchor body of FIGS. 3A-3C;

FIGS. 7A-B illustrate a method of using the tissue fixation device of FIG. 2 in a pound-in approach;

FIGS. 8A-B illustrate a method of using the tissue fixation device of FIG. 4 in a pull- in approach; and

FIGS. 9A-10E illustrate alternative tissue fixation devices and methods of this disclosure for use in a PCL reconstruction. DETAILED DESCRIPTION

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.

Turning now to FIG. 1 A, an anchor body 102 of an exemplary tissue fixation device 100 of this disclosure is shown. The anchor body 102 is generally elongated and includes a distal end 104, a proximal end 106 and a longitudinal axis L extending therebetween. The distal end 104 of the anchor body 102 is further adapted for insertion into bone. For example, as illustrated in FIG. 1 A, the distal end 104 of the anchor body 102 includes a tapered portion 108. The tapered portion 108 of the anchor body 102 may terminate in a generally flat tip

109, although other configurations, such as a rounded tip or a sharp tip, are contemplated by this disclosure. The anchor body 102 also includes a cannulation 110 extending from the distal end 104 to the proximal end 106 of the anchor body 102 along the longitudinal axis L. The cannulation 110 may have a circular cross-section, as shown in FIG. 1 A, or have other non-circular configurations, as further described below.

The anchor body 102 may further include surface features which provide improved fixation strength of the anchor body 102 within a bone hole or tunnel. For example, in FIG. 1 A, the anchor body 102 includes a plurality of channels 112 formed in the outer surface of the anchor body 102. The plurality of channels 112 in turn define a plurality of ribs 114 therebetween that are circumferentially spaced about the anchor body 102. It is contemplated by this disclosure that both of the tapered region 108 and the ribs 114 on the anchor body 102 may have additional features or a texture to aid in the insertion of the anchor body 102 into bone and/or to prevent pull-out of the anchor body 102. The outer surface of the anchor body 102 may also comprise additional longitudinal channels to allow for passage of a tissue graft.

The anchor body 102 can be made from any combination of metal, polymers, bioabsorbable, or biocomposite material. For example, the anchor body 12 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 - hydroxy apatite (PLLA-HA), poly-D-lactide (PDLA), 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, the entirety of which is herein incorporated by reference. A copolymer of polyglycolic acid (PGA) and polytrimethylene carbonate (TMC) is another example of a bioabsorbable material. Other commonly used materials that are capable of providing the strength needed to set the anchor body 102 and to hold a tissue graft in position while bone-to-tissue in-growth occurs are also contemplated by this disclosure.

FIG. IB shows a partial cross-section of the anchor body 102, including the tapered portion 108. In FIG. IB, it can be seen that the cannulation 110 of the anchor body 102 comprises two portions having different diameters. The proximal portion 118 of the internal cannulation 110 has a diameter D¹ that is selected to be larger than the diameter D² of the distal portion 120. Thus a shelf 116 (FIG. 1C) is defined by the transition between diameters D¹ and D². The shelf 116 may be located at any region of the cannulation 110 between the proximal end 106 and the distal end 104 of the anchor body 102, but is preferably located near to the beginning of the tapered end 108. The use of the shelf 116 will be further described below.

Turning now to FIG. 2, in addition to the anchor body 102, the tissue fixation device 100 of this disclosure also includes an impactor 120 attached to a flexible element, such as a guide wire 122. In examples, the impactor 120 may be an elongated plug comprised of the same or a different material than the anchor body 102. In FIG. 2, the impactor 120 is shown as being cylindrical. However, it is also contemplated by this disclosure that the impactor 120 may not be cylindrical, as long as the impactor 120 is sized and shaped to be slidably received inside the cannulation 110 of the anchor body 102. The impactor 120 is attached to the proximal end of the guide wire 122 while the distal end of the guide wire 122 is passed through the cannulation 110 such that it exits the distal end 104 of the anchor body 102. Use of the impactor 120 and the guide wire 122 will be described in more detail below.

In FIGs. 3 A-C, an alternative example of an anchor body 202 of a tissue fixation device 200 of this disclosure is shown. In FIG. 3 A, the anchor body 202 is generally elongated and includes a distal end 204, a proximal end 206 and a longitudinal axis L extending therebetween. The distal end 204 of the anchor body 202 includes a tapered portion 208 terminating in a generally flat tip 209. The anchor body 202 also includes a cannulation 210 extending from the distal end 204 to the proximal end 206 of the anchor body 102. At the distal end 204 of the anchor body 202, the cannulation 210 has a circular cross- section. In the example of FIG. 3 A, the anchor body 202 also includes a plurality of channels 212 formed in the outer surface of the anchor body 202. The plurality of channels 212 in turn define a plurality of ribs 214 therebetween that are circumferentially spaced about the anchor body 202 and extend into the tapered portion 208 of the anchor body 202.

FIG. 3B shows a perspective view of the anchor body 202 of FIG. 3 A from the proximal end 206. As can be seen in the example of FIG. 3B, the plurality of channels 212 taper in width from the distal end 204 to the proximal end 206 of the anchor body 202.

Conversely, the plurality of ribs 214 taper in width from the proximal end 206 to the distal end 204 of the anchor body 202. Thus, in cross-section, the plurality of ribs 214 form a daisy configuration about the proximal face 205 of the proximal end 206. Furthermore, at the proximal end 206, the cannulation 210 has a cross-shaped cross-section, as shown in more detail in FIG. 3C.

FIG. 3C shows the cannulation 210 of the anchor body 202 comprising two portions having different diameters. The proximal portion 218 of the cannulation 210 has a diameter D³, while the distal portion 220 has a diameter that tapers from the diameter D³ to a diameter D⁴. The taper of the cannulation 210 generally follows the tapered portion 208 of the anchor body 202. Additionally, the cannulation 210 transitions from a cross-shaped cross-section at the proximal end 206 of the anchor body 202 to the circular cross-section at the distal end 204 of the anchor body 202.

FIG. 4 illustrates the tissue fixation device 200 of this disclosure with the anchor body 202 as shown in FIGs. 3 A-C. In FIG. 4, the tissue fixation device 200 includes an impactor 220 attached to a flexible element, such as a guide wire 122. In the example shown, the impactor 220 has a cross-shaped outer surface to match the cross-shaped diameter of the cannulation 210. In addition, the impactor 220 is tapered to match the taper of the

cannulation 210 from the diameter D³ to the diameter D⁴. The impactor 220 further includes a proximal stop 224 having a diameter selected to be larger than the diameter D³. The impactor 220 is attached to the proximal end of the guide wire 222 while the guide wire 222 is passed through the cannulation 210 such that it exits the distal end 204 of the anchor body 202. Use of the impactor 220 and guide wire 222 will be described in more detail below.

Still further examples of the anchor body 302, 402 are shown in FIGs. 5 A-C and 6A- B. In FIGs. 5A-C, the anchor body 302 is substantially the same as the anchor body 202 of FIGS. 3 A-C except that the plurality of ribs 314 spiral about the surface of the anchor body 302 in a screw-like manner. In FIGs. 6A-B, the plurality of ribs 414 are circumferential rather than linear. In both examples, the plurality of ribs 314, 414 provide improved fixation strength of the anchor body 302, 402 within a bone hole or tunnel.

It should be noted that the tissue fixation device 100, 200 of this disclosure can be used in a traditional "pound-in" approach, as shown in FIGs. 7A-B. In FIG. 7A, the anchor (shown for exemplary purposes as anchor body 102) is coupled to a driver 130 having a handle 132 and a shaft 134 configured for driving the anchor body 102 into bone. A bone hole 136 may be formed in either or both of the femur 138 and tibia 140 by standard means known to one of skill in the art. The driver 130 is then used to pound the anchor body 102 into the bone hole(s), beginning from inside the joint 142 for the femur 138, and from the tibial cortex 144 for the tibia 140. However, the tissue fixation device 100, 200 of this disclosure also allows for innovative surgical techniques to be used, as described below.

The discussion will now turn to FIGs. 8A-B, which illustrate a method of using the tissue fixation device 100, 200 of this disclosure in a "pull-in" approach in an interference fixation. As stated above, the tissue fixation device 100, 200 of this disclosure generally serves to fix a tissue graft inside of a bone hole. The tissue graft may be a replacement ACL, although the tissue fixation device 100, 200 described herein may also be usable in other orthopedic applications.

As shown in FIG. 8A, a bone hole 146 is first created in bone, e.g., the tibia 140 and the femur 138. The bone hole 146 may be created either by an outside-in or an inside-out approach. In the knee joint 142, one end of a tissue graft 152 is wrapped around or otherwise attached to the anchor body (shown for exemplary purposes as anchor body 202). The guide wire 222, with the impactor 220 attached at its proximal end, is passed through the anchor body 202 and the bone hole 146 such that it exits through the skin of the patient's body.

Next, an instrument capable of generating a distal force, such as a surgical slap hammer (not shown), is attached to the guide wire 222 extending outside of the patient's body. Surgical slap hammers typically consist of a sliding weight mounted to a rod which may be thrown upward, generating a jerking distal force when the sliding weight strikes a stop at the distal end of the rod. The jerking force in turn causes the impactor 220 to enter the anchor body 202 and the stop member 224 to repeatedly strike against the proximal face 205 of the anchor body 202. This in turn urges the anchor body 202 to enter the bone hole 146 by degrees, whereby the anchor body 102 and tissue graft 152 become lodged against the bone hole 146. Thus, the slap hammer or other instrument may be used to pull in the direction P, rather than push, the anchor body 102 into the bone hole 146. Alternatively, in the example of the tissue fixation device 100 of FIG. 2, the distal force causes the impactor 120 to enter the cannulation 110 of the anchor body 102 and repeatedly strike against the shelf 116. It is also contemplated by this disclosure that anchor body 102 may not be cannulated, so that the impactor 120 strikes a solid proximal face at the proximal end 106 of the anchor body 102. It should be noted that the cross-shaped cross-section of the impactor 220

advantageously provides more rotational control over the anchor body 202 as compared to the cylindrical impactor 120. That is, the tissue graft 152 which the anchor body 202 is used to secure may not be in the most desirable position in the bone hole 146 when the anchor body 202 is initially installed. The ability to rotate the anchor body 202 via the cross-shaped impactor 220 allows the tissue graft 152 to be placed in a more desirable location. This provides a higher level of precision when placing the anchor body 202 in and around the tissue graft 152. It is also contemplated by this disclosure that the impactor 220 may have other cross-sectional shapes, for example, triangular, square, hexagonal, etc., which allow the ability to rotate the anchor body 202 via the impactor 220.

As shown in FIG. 8B, the tissue fixation device 100, 200 may also be used in suspension fixation of the tissue graft 152, rather than the interference fixation of FIG. 8 A. In FIG. 8B, the anchor body 202, with one end of the tissue graft 152 attached thereto, is secured in the femur 138 and attached to a suture 150. The suture 150, in turn, is passed through the other end of the tissue graft 152 and pulled through the bone hole 146 in the tibia 140. The suture 150 is then attached to an auxiliary fastening device 154, such as a cortical button, which, after tensioning, rests against the outer cortex 144 of the tibia 140. Non-limiting examples of cortical buttons are shown and described in U.S. Patent No. 6,517,578 to Hein, and in the Endobutton family of products (manufactured by Smith & Nephew, Inc., Andover, MA, USA), incorporated herein by reference.

Turning now to FIGS. 9A-11, variations of the tissue fixation devices and methods of this disclosure can be used to repair a PCL. In FIGS. 9A-11, the tissue fixation devices generally serve to fix two tissue grafts inside of a bone hole at different levels of tension. The tissue grafts may be a replacement PCL, although the tissue fixation devices described herein may also be usable in other orthopedic applications.

FIG. 9A-D illustrate an exemplary tissue fixation device 500 of this disclosure having an anchor body 502 similar to the anchor body 102 of FIG. 1 A. The anchor body 502 is generally elongated and includes a distal end 504 and a proximal end 506. The distal end 504 of the anchor body 502 includes a tapered portion 508 terminating in a generally flat tip 509. The anchor body 502 also includes an open cannulation 510 extending from the distal end 504 to the proximal end 506 of the anchor body 502. The cannulation 510 may have a circular cross-section with a smooth inner surface. In addition, the cannulation 510 of anchor body 502 is open to the exterior of the anchor body 502 through an opening 512 extending from the distal end 504 to the proximal end 506 of the anchor body 502. The anchor body 502 is used in combination with a driver 530 having a handle 532 and a shaft 534. The shaft 534 is coupled to the anchor body 502 while allowing for a graft 552 to pass through the cannulation 510 of the anchor body 502. The driver 530 is configured for driving the anchor body 502 into bone in a pound-in approach, as described above with regard to FIGS. 7 A and 7B. In use, the anchor body 502 is inserted into bone 540 with a first graft 552a on the outside of the anchor body 502, and a second graft 552b on the inside of the anchor body 502, as shown in FIG. 9E. After insertion of the anchor body 502, the first graft 552a is secured in the repair site by the surrounding bone tunnel 546. A fixation device 514, such as a screw, is then used to fixate the second graft 552b inside the anchor body 502.

FIGS. 10A-D illustrate another example of a tissue fixation device 600 of this disclosure having an anchor body 602 similar to the anchor body 102 of FIG. 1 A. The anchor body 602 is generally elongated and includes a distal end 604 and a proximal end 606. The distal end 604 of the anchor body 602 includes a tapered portion 608 terminating in a generally flat tip 609. The anchor body 602 also includes an open cannulation 610 extending from the distal end 604 to the proximal end 606 of the anchor body 602. The cannulation 610 may have a circular cross-section with a smooth inner surface. The anchor body 602 is used in combination with a driver 630 having a handle 632 and a shaft 634. The shaft 634 is coupled to the anchor body 602 while allowing for a graft 652 to pass through the cannulation 610 of the anchor body 602. This is accomplished by pairing the anchor body 602 with a sleeve 620 coupled to the shaft 634 of the driver 630. The driver 630 is configured for driving the anchor body 602 into bone in a pound-in approach, as described above with regard to FIGS. 7A and 7B. The anchor body 602 is also used to fixate two separate grafts 652a, 652b in bone 640 under different levels of tension, as shown in FIG. 10E.

While this disclosure has been particularly shown and described with references to preferred examples 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. Rather, any limitations to the disclosure are presented in the following claims.

Claims

1. A tissue fixation device, comprising:

an anchor comprising a generally elongated anchor body having a proximal end, a tapered distal end, and a cannulation extending along a longitudinal axis therebetween, the cannulation having a proximal portion and a distal portion, a diameter of the proximal portion selected to be larger than a diameter of the distal portion;

an impact member, a distal end of the impact member attached to a flexible element, the impact member sized and shaped to be slidably received within at least the proximal portion of the cannulation of the anchor body when the flexible element is inserted through the cannulation such that it exits the distal end of the anchor body;

wherein, when a repeated force is applied to the flexible element, the force causes the impact member to urge the anchor body into a bone hole formed in bone.

2. The tissue fixation device of claim 1, further comprising a shelf defined by the transition between the diameter of the proximal portion and the diameter of the distal portion.

3. The tissue fixation device of claim 1, wherein the anchor body comprises surface features for improving fixation strength of the anchor body within a bone hole or tunnel.

4. The tissue fixation device of claim 3, wherein the surface features are longitudinal ribs.

5. The tissue fixation device of claim 1, wherein the distal portion of the cannulation is tapered.

6. The tissue fixation device of claim 1, wherein the proximal portion of the cannulation has a circular cross-section.

7. The tissue fixation device of claim 1, wherein the proximal portion of the cannulation has a cross-shaped cross-section.

8. The tissue fixation device of claim 1, wherein the impact member has a circular cross- section.

9. The tissue fixation device of claim 1, wherein the impact member has a cross-shaped cross-section.

10. The tissue fixation device of claim 1, wherein a distal end of the impact member is tapered.

11. The tissue fixation device of claim 1, wherein the impact member has a proximal stop having a diameter selected to be larger than the diameter of the proximal portion of the cannulation.

12. A method of tissue fixation comprising:

attaching a first end of a tissue graft to an anchor, the anchor comprising a generally elongated anchor body having a proximal end, a tapered distal end, and a cannulation extending along a longitudinal axis therebetween, the cannulation having a proximal portion and a distal portion, a diameter of the proximal portion selected to be larger than a diameter of the distal portion;

passing a flexible element through the cannulation of the anchor body such that a distal end of the flexible element exits the distal end of the anchor, the proximal end of the flexible element attached to an impact member, the impact member sized and shaped to be slidably received within at least the proximal portion of the cannulation;

attaching a source of distal force to a distal end of the flexible element; and repeatedly applying the distal force to the flexible element such that the impact member repeatedly strikes a portion of the anchor body, the force causing the anchor body and the tissue graft to move distally together into a first bone hole formed in a first bone.

13. The method of claim 12, wherein the flexible element is a guide wire.

14. The method of claim 12, further comprising forming the first bone hole in the first bone.

15. The method of claim 12, wherein the impact member repeatedly striking a portion of the anchor body comprises the impact member repeatedly striking a shelf defined by the transition between the diameter of the proximal portion and the diameter of the distal portion of the cannulation of the anchor body.

16. The method of claim 12, wherein the impact member comprises a proximal stop having a diameter selected to be larger than a diameter of the proximal portion of the cannulation.

17. The method of claim 16, wherein the impact member repeatedly striking a portion of the anchor body comprises the proximal stop of the impact member repeatedly striking a proximal face of the anchor body.

18. The method of claim 12, further comprising forming a second bone hole in a second bone, the second bone adjacent to the first bone.

19. The method of claim 18, wherein the tissue graft is secured to the first bone hole and to the second bone hole by interference fixation.

20. The method of claim 18, wherein the tissue graft is secured to the first bone hole and to the second bone hole by suspension fixation.