Anchor and Anchor Installation Tool and Method

The present invention relates to anchors for fastening one component to another component, and in particular, to a medical anchor implantable in organic tissue. Even more particularly, the present invention relates to a suture anchor which can be implanted into organic tissue, for example bone, to anchor a suture in the bone. The invention also relates to an instrument for inserting the anchor as well as a method for inserting the anchor, particularly into organic tissue. Although the present invention is described as a suture anchor, the invention also is suitable as an anchor for anchoring other devices, for example prostheses. Furthermore, the invention is not limited to the surgical or medical field, and can be used to implant anchors into media other than tissue, e.g., into wood or plastic.

Examples of two prior art anchors include the device described in U.S. Pat. No. 5,002,550 and the anchor described in U.S. Pat. No. 5,141,520.

In both of these references, a suture anchor is described. In U.S. Pat. No. 5,002,550, a suture anchor and installation tool are described. The suture anchor has a curved barb which is flexed upon insertion into a bore and which engages the wall of the bore to maintain the anchor in position. In U.S. Pat. No. 5,141,520, a harpoon type of suture anchor is described which is driven into the bone by a hammer force.

In both devices of the prior art, the suture anchors must be forcibly driven into a bore provided in bone, for example. In the device in the '550 patent, a flexible barb must be deformed as it is inserted into the bore, and in the device of the '520 patent, the anchor has surfaces disposed on its periphery which wedge the anchor into the bone. Accordingly, in both of these types of anchors, there is the possibility of damage to the material in which the anchor is being inserted due to the force which is exerted in implanting the anchor.

In addition, in both of the references, the anchors disclosed are not fixedly attached to the insertion tool which is provided for inserting the anchor into the organic tissue. Accordingly, the anchors can fall off the distal ends of the insertion devices. Therefore, in both of these references, the anchor is not fully stabilized during the implantation process and may become misaligned or completely fall off the distal end of the insertion tool.

It is, therefore, an object of the present invention to provide an anchor, particularly a suture anchor, which overcomes the described problems of the prior art.

It is yet still a further object of the present invention to provide an anchor which allows for the placement of the anchor with high accuracy.

It is yet still a further object of the present invention to provide an anchor which can be implanted into organic tissue and which is easily implanted without the risk of misalignment or disconnection from the insertion tool.

It is yet still a further object of the present invention to provide an insertion tool for the described anchor.

It is yet still a further object of the present invention to provide an insertion tool which allows for convenient and simple insertion of an anchor into organic tissue.

It is yet still a further object of the present invention to provide an insertion tool and anchor which prevents damage to the tissue in which the anchor is being inserted during the installation procedure.

It is yet still a further object of the present invention to provide a pre-packaged anchor and anchor insertion tool, and particularly an anchor and insertion tool which is adapted for a single use, the insertion tool being thereafter disposable.

It is yet still a further object of the present invention to provide an insertion tool which is inexpensive to manufacture and accordingly, economically used in a disposable fashion.

The above and other objects of the present invention are achieved by an apparatus for inserting an anchor into a bore in a medium, the anchor being adapted to engage the walls of the bore for securing the anchor into the medium, the apparatus comprising: a first manually graspable member having a distal end and a proximal end, the distal end being adapted to releasably receive the anchor, said manually graspable member having a central opening therethrough, the proximal end of the manually graspable member having a pivotable handle extending therefrom; a second member movable longitudinally in the central opening attached to said pivotable handle and to said anchor; a release member releasably coupling said anchor to said second member; said pivotable handle being pivotable with respect to said first member and exerting a force longitudinally on said second member to move said second member longitudinally in said first member and exert a force on said anchor connected thereto to deform said anchor to cause said anchor to engage the walls of the medium thereby to secure the anchor in the medium; said force exerted on said second member further acting on said release member to separate said anchor from said second member when said anchor has deformed to engage the walls of the bore.

The above and other objects of the present invention are also achieved by a method of securing an anchor into a bore in a medium, the anchor being adapted to engage the walls of the bore for securing the anchor into the medium, the method comprising: inserting an anchor held to a distal end of an insertion tool into the bore; applying a force to a lever extending from the insertion tool to cause a force to be exerted on the anchor by a coupling member to deform the anchor into engagement with the walls of the bore in the medium and separating the anchor from the coupling member; and pulling the insertion tool away from the anchor leaving the anchor secured in the bore in the medium.

The above and other objects of the invention are furthermore achieved by apparatus for inserting an anchor into a bore in a medium, the anchor being adapted to engage the walls of the bore for securing the anchor into the medium, the apparatus comprising: an anchor comprising at least one hollow cylindrical section having one of proximally or distally extending fingers adapted to be deformed radially outwardly to engage the walls of the bore to secure the anchor in the medium; a first manually graspable member having a distal end and a proximal end, the distal end releasably receiving the anchor, said manually graspable member having a central opening therethrough, the proximal end of the manually graspable member having a pivotable handle extending therefrom; a second member movable longitudinally in the central opening attached to said pivotable handle and to said anchor; a release member releasably coupling said anchor to said second member; said pivotable handle being pivotable with respect to said first member and exerting a force longitudinally on said second member to move said second member longitudinally in said first member and exert a force on said anchor connected thereto to deform said anchor to cause said anchor to engage the walls of the medium thereby to secure the anchor in the medium; and said force exerted on said second member further acting on said release member to separate said anchor from said second member when said anchor has deformed to engage the walls of the bore.

The above and other objects of the invention are additionally achieved by an anchor for implantation in a bore in a medium, the anchor comprising: a cylindrical hollow section having a plurality of longitudinally extending fingers for outward radial movement for engaging the walls of the bore in response to a force applied to the anchor by an insertion tool causing the fingers to move against a cam surface; and a central longitudinally extending member extending through the hollow section and having a shoulder at a distal end preventing movement proximally past the hollow section, the central member having a shaft for engagement by the insertion tool, said central member including a releasable connection for separating a distal portion of the central member from a proximal portion of the central member coupled to the insertion tool.

Other objects, features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.

The invention will now be described in greater detail in the following detailed description with reference to the drawings, in which:

FIG. 1 shows the anchor and anchor insertion tool according to the present invention in perspective view in use;

FIG. 2 shows the anchor and anchor insertion tool of FIG. 1 during the initial deployment of the anchor;

FIG. 3 shows the anchor and anchor insertion tool once the anchor has been fully deployed;

FIG. 4 schematically shows, in perspective view, an embodiment of an anchor employed with the insertion tool according to the present invention;

FIG. 5 shows the anchor and anchor insertion tool of FIG. 4 with the anchor in its deployed position;

FIG. 6 is a longitudinal cross section of the anchor and anchor insertion tool according to the present invention prior to deployment;

FIG. 6A is a cross section of the device shown in FIG. 6 along lines 6A--6A;

FIG. 6B is a longitudinal cross section showing the anchor and a portion of the anchor insertion tool in a cross sectional view rotated by 90.degree. from the view shown in FIG. 6;

FIG. 7 is a longitudinal cross section showing the anchor and anchor insertion tool after sutures have been threaded into the anchor during manufacture and the distal tip of the anchor crimped to prevent the suture from coming out of the anchor at the distal end;

FIG. 8 is a longitudinal cross section showing the anchor and anchor insertion tool after the anchor has been deployed but prior to removal of the insertion tool from the anchor;

FIG. 9 is a longitudinal cross section showing the anchor and anchor insertion tool after the anchor has become detached from the actuating portion of the insertion tool and just prior to removal of the insertion tool from the anchor;

FIG. 10 shows the insertion tool with anchor attached in a perspective view;

FIG. 11 is an exploded view of the anchor and distal end of the insertion tool;

FIG. 12 is a longitudinal cross section showing the proximal end of the insertion tool, showing the actuating handle;

FIG. 13 is a longitudinal cross section showing the proximal end of the insertion tool rotated 90.degree. with respect to that shown in FIG. 12;

FIG. 14 is a longitudinal cross section showing a portion of the proximal end of the insertion tool, showing the initial step employed during securement of the anchor;

FIG. 15 is a longitudinal cross section showing a further step during the securement of the anchor;

FIG. 16 is a longitudinal cross section showing yet a further step during the activation of the anchor when the actuating portion of the insertion tool has become detached from the anchor;

FIG. 17 is a longitudinal cross section showing another embodiment of the proximal end of the insertion tool, showing a different embodiment of the handle employed for actuating the anchor;

FIG. 18 is a longitudinal cross section showing a first step during the securement of the anchor according to the device shown in FIG. 17;

FIG. 19 is a longitudinal cross section showing a further first step in the securement of the anchor having a handle according to FIG. 17;

FIG. 20 shows the embodiment of the proximal end of the insertion tool, shown in FIG. 17, in perspective view;

FIG. 21 is a longitudinal cross section showing the distal end of the insertion tool having an anchor of the type shown in FIGS. 4 and 5 having engaging fingers extending both proximally and distally;

FIG. 21A is a cross section taken along lines 21A--21A of FIG. 21;

FIG. 22 is a longitudinal cross sectional view through the anchor shown in FIG. 21;

FIG. 23 is a longitudinal cross section showing the anchor of FIG. 22 rotated by 90.degree. and also showing the sutures threaded through the anchor with the tips of the anchor crimped during the manufacturing process; and

FIG. 24 is a longitudinal cross section showing the distal end of the anchor insertion tool and the anchor upon deployment of the anchor and just prior to separation of the anchor insertion tool from the anchor.

With reference now to the drawings, FIGS. 1, 2 and 3 show one embodiment of the anchor installation tool according to the present invention in perspective view and showing the insertion tool during progressive steps in deployment of a surgical anchor. The surgical anchor employed in the present invention is a modification of the surgical anchor described in detail in applicant's co-pending U.S. application Ser. No. 08/294,407 filed Aug. 22, 1994. An example of such an anchor is shown in FIGS. 4 and 5. The anchor shown in FIGS. 1, 2 and 3 is similar to the anchor shown in FIGS. 4 and 5. However, the anchor shown in FIGS. 1, 2 and 3 is of the type having fingers 15 which extend only proximally. The anchor shown in FIGS. 4 and 5 has fingers 15 which extend both proximally and distally.

The installation tool according to the present invention can be used with anchors of the type shown in FIGS. 4 and 5 and also with anchors having fingers 15 extending only proximally or only distally, i.e., anchors having only a portion 10 or 20 with fingers extending only proximally or only distally.

As shown in FIGS. 4 and 5, an anchor insertable into a bore in organic tissue, for example a bore drilled in bone, may comprise two sections 10 and 20. Section 20 includes proximally extending fingers 15 and section 10 includes distally extending fingers 15. The fingers are interdigitated in this embodiment. The fingers 15 of the anchor 22 include chamfered edges 16 which are adapted to engage with corresponding opposed chamfered surfaces 17 of the opposed section. When the two sections 10 and 20 are moved relatively toward each other, the opposed chamfered surfaces 16 and 17 force the fingers 15 radially outwardly, as shown in FIG. 5, causing the fingers to engage in the bore drilled in the organic tissue, thereby fixing the anchors in the organic tissue.

As described above, the anchor may include only a single section 10 or 20 having only proximally extending fingers 15. In such a case, the anchor is moved against a surface of the installation tool, as will be described in greater detail herein, causing the fingers to move outwardly and to engage the wall of the bore, thereby preventing the anchor from being pulled out of the bore.

As shown in FIG. 1, the device according to the present invention comprises an insertion tool generally designated 30. The insertion tool includes a cylindrical hollow body portion 32, a pivotable handle actuating portion 34 and a distal portion 36 for supporting and forming the anchor 22. The member 32 need not be cylindrical, it can take any other convenient, ergonomic form. In FIG. 1, the anchor is shown prior to formation. The anchor includes a plurality of proximally extending fingers 15. In FIG. 2, the anchor 22 is shown after the plurality of fingers 15 have been moved radially outwardly to allow the fingers to engage in a bore in organic tissue.

The hollow member 32 includes at least one, and preferably two, openings or windows 38 at its distal end through which sutures 40, with any suitable surgical needles 42 attached, extend. If two openings 38 are provided, they are located on opposed surface of member 32. As explained herein in greater detail, the anchor 22 also includes a central tip portion 22A, not shown in FIGS. 4 and 5, but shown in the other figures, the purpose for which will be explained in greater detail below.

As shown in FIGS. 1, 2 and 3, the insertion tool is grasped as shown by the user's fingers 44. The user's thumb 46 is placed against the handle actuating portion 34 and the anchor 22 is inserted into the opening, not shown, in the organic tissue. It will be noted that because the fingers 15 do not extend outwardly initially beyond the diameter of the anchor 22 and the diameter of the bore is sized to be only slightly larger than the diameter of the undeployed anchor, the anchor can be inserted very easily, without applying any force to the organic tissue. Thus, unlike the prior art, the organic tissue cannot be damaged during the insertion process. Once the anchor has been inserted into the bore in the organic tissue, the operator applies a transverse force to the handle 34, pivoting the handle 34, which is preferably coupled to the cylindrical portion 32 via frangible connection 48, causing the distal portion of the handle 34 to pivot and cam against the surface of portion 70 of the cylindrical portion 32. As will be explained in greater detail below, the handle portion 34 is coupled to the anchor 22 via a flexible connection, for example a cable or wire 52, causing a force to be transmitted to anchor 22 when handle 34 pivots. This causes the anchor 22 to be moved against a chamfered surface 17 of the installation tool at the distal end, thereby forming the anchor 22 into engaging position as shown in FIG. 2. The fingers 15 of the anchor thereby move outwardly to cause the anchor to engage the walls of the bore in the organic tissue.

Upon further pivoting of the handle portion 34 into the position shown approximately in FIG. 3, a frangible connection at the distal end, to be shown in greater detail below, connecting the anchor 22 itself to a member connected to the wire 52, breaks, thereby disconnecting the insertion tool from the anchor, leaving the anchor, with the sutures 40 attached thereto, deployed in the organic tissue. The sutures 40 extend through openings 38 in the tool and can be retracted through the opening 38 to allow the insertion tool 30 to be separated from the sutures. The anchor 22 with sutures attached is thereby left in the bore ready for the connection to another component, for example a prosthesis or other organic tissue.

FIGS. 6-9 show an embodiment of the insertion tool according to the present invention used to implant an anchor having only proximally extending fingers 15. The insertion tool 30 includes a hollow cylindrical member 32, through which extends a flexible element, for example a cable or wire 52. The cylindrical element 32 receives at its distal anchor-supporting end 36, an insert 54 having a frustoconically shaped surface 56. The insert 54 has a cylindrical proximally extending portion 58 adapted to be received in the hollow bore of the cylindrical member 32. The insert 54 tapers again at its distal end at a portion 60, terminating in a terminal portion 62 having a chamfered surface 17 adapted to engage the chamfered surfaces 16 of fingers 15, thereby to form fingers 15 outwardly when the anchor 22 moves toward the chamfered surface 17 of the insert 54. As best shown in FIG. 11, insert 54 comprises two half sections 54A and 54B.

Flexible element 52 is fixedly attached to a coupling member 64, as shown more clearly in FIG. 11. The anchor 22, for example as shown in FIG. 11, of the type having only proximally extending fingers (but which could have both proximally and distally extending fingers as shown in FIGS. 4 and 5), is slidably received on a threaded shaft 66, which is preferably integrally coupled to tip portion 22A. Tip portion 22A is releasably coupled to threaded shaft 66, preferably via a frangible connection 68 comprising a portion of shaft 66 of reduced cross section, e.g., a slit or score line causing the shaft to have reduced tensile strength at this point.

Coupling member 64 includes internal threads which receive threads 70 of the threaded shaft 66, thereby capturing anchor 22 between the shoulder of forked tip 22A and chamfered tip portions 17 of portions 54A and 54B of insert 54.

Threaded shaft 66 includes longitudinally extending slots 72 on opposed sides thereof, through which sutures 40 can be longitudinally received, at least in part. The sutures 40 thereafter extend through the windows 38 formed in the two half portions designated 54A and 54B of the insert 54.

As shown in FIG. 11, during the assembly process, the sutures 40 are threaded into a slot 22AA provided in the forked tip 22A. One or a plurality of sutures may be threaded through the slot 22AA in such a way that the suture is looped around the base portion of the slot 22AA, and thence extending longitudinally along a portion of the slots 72 in the threaded shaft 66. The respective ends of the sutures 40 thereafter extend through the openings 38 in the insert 54. Once the sutures 40 have been inserted into the slot 22AA, the two opposed portions 22A' and 22A" are crimped together, as shown in FIGS. 7, 8 and 9. This secures the sutures in position and prevents them from slipping out of the slot 22AA in the tip 22A. The anchor assembly 22 with shaft 66 is threaded into coupling member 64 and insert 54 halves 54A and 54B are assembled to maintain the assembly together. During assembly, the ends of sutures 40 are threaded through the openings 38.

FIGS. 12-16 show the proximal end of the insertion tool, according to one embodiment of the invention. The proximal end includes an actuating handle 34 which may be integrally connected to an insert portion 70 received within the bore of the proximal portion of cylindrical member 32. Handle 34 and portion 70 are releasably coupled, preferably by a frangible connection 48 comprising an area between handle 34 and portion 70 of reduced cross section and accordingly, reduced tensile strength. Wire for cable 52 is coupled to a proximal coupling element 74 which is threaded into an internal bore 34A in handle 34, as shown at 76.

As shown in FIG. 14 and with reference to FIGS. 6 to 9, to activate and deploy the anchor 22, the anchor 22, attached to the device 30 preferably during assembly of the tool, is inserted into the bore in the organic tissue, for example a bore in bone. The anchor 22 is inserted into the bore without applying any force to the organic tissue because the fingers 15 of the anchor 22 are undeployed i.e., in their unextended position. To deploy the anchor 22, the user applies a transverse force to handle 34, thus breaking the frangible connection 48 and pivoting the handle portion 34. The handle portion 34 has a distal portion 34A which is engageable with a proximal surface 70A of the portion 70. The pivoting cam action of the handle 34 causes a tension to be applied to the wire 52, causing it to move in the direction shown by the arrow 78. This causes the fingers 15 of the anchor 22 to move against the chamfered surface 17 of the insert 54 at the distal end of the insertion tool. After the frangible connection 48 at the distal end of the handle 34 breaks, the pivoting cam motion of the handle 34 is continued. As the wire 52 pulls the anchor 22 in the proximal direction, the fingers 15 move against surface 17 and begin to move radially outwardly, as shown in FIG. 8. The fingers 15 thus engage in a bore into which the anchor 22 has been inserted. Upon further pivoting of the handle 34, as shown in FIG. 15, the frangible connection 68 at the distal end of the insertion tool i.e., the frangible connection 68 connecting the tip portion 22A to the threaded shaft 66, breaks, thereby disconnecting the shaft 66 from the tip portion 22A of the anchor 22, leaving the handle 34 free, as shown in FIG. 16. The insertion tool 30 can now be withdrawn, leaving the anchor 22 with the tip portion 22A through which the sutures 40 are threaded in position in the bore in the organic tissue. At this point, the sutures 40 still extend through the openings 38 in the distal end of the insertion tool 30. By suitable threading of the sutures through the openings 38, the insertion tool 30 can be removed completely from the sutures. The suture anchor 22 with attached sutures is now fixed in position within the bore hole.

FIGS. 17-20 shown an alternative embodiment of the handle portion of the present invention. As shown in these figures, a handle 34' is provided suitably formed to provide a convenient surface for actuating by the hand of the user.

As in the embodiment shown in FIGS. 12-16, in the initial position, the wire 52 is relatively unstressed or has just enough tension to maintain the anchor 22 such that the chamfered surfaces 16 of the fingers 15 of the anchor 22 and the corresponding surface 17 of the member 54 are in engagement. To actuate the anchor 22, the user pivots the handle 34', breaking the frangible connection 48'. As shown, point A of the wire 52 moves to the position shown in FIG. 18. Points B and C move as shown. At some point, point B moves to the position illustratively shown, at which point the fingers 15 of the anchor 22 begin to deploy. Upon further pivoting of the handle 34', illustratively shown in FIG. 19 where point C has moved to the point adjacent the top surface 70A' of the member 70', the anchor is fully deployed and the frangible connection 68 coupling the anchor 22A to the threaded shaft 66 breaks, allowing the insertion tool to be removed from the anchor, leaving the anchor 22 in position in the bore hole.

FIGS. 21, 21A and 22-24 show the distal end of the insertion tool according to the present invention wherein the anchor 22 comprises an anchor having proximally and distally extending fingers 15, as shown in FIGS. 4 and 5. In this embodiment, the distal tip of the member 54' is formed with a straight cut edge 17', thereby abutting one portion 10 of the anchor 22. The embodiment shown in these figures operates in the same way as in the other embodiments previously described. Tension in the wire 52 caused by pivoting of the handle 34 causes the member 20 to be moved against the member 10 of the anchor 22. Member 10 abuts surface 17', and thus is prevented from moving. The fingers 15 thus move into the positions shown in FIG. 24, thereby securing the anchor 22 into a bore. When the anchor 22 shown in FIG. 24 is secured into a bore in a medium, the anchor is prevented from moving in either proximal or distal directions. In contrast, the anchor shown in the embodiment described with reference to FIGS. 6 and 9 prevents movement of the anchor proximally. However, in such an embodiment, it is assumed that forces tending to move the anchor in a distal direction will not be provided to the anchor or that even if provided, the anchor is disposed in a "blind" or "bottomed" hole, and thus is prevented from moving distally.

As will be appreciated by those of skill in the art, the anchor 22, central member 22A and shaft 66, if provided as a suture anchor, are made of a suitable biocompatible material, e.g., metal or plastic. The remainder of the instrument can be made of suitable plastic or metal, as appropriate. Preferably, the entire tool, with anchor assembled thereon, is pre-packaged, preferably sterilized, as a unit for a single use. The insertion tool can, after implanting the anchor, be discarded. Or course, the device of the invention can also be employed reusably or recycled, after suitable sterilization, as appreciated by those of skill in the art.

Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore the present invention should be limited not by the specific disclosure herein, but only by the appended claims.