HK1132162B - Dual thread cannulated suture anchor - Google Patents

Description

Double thread cannulated suture anchor

Technical Field

The present invention relates generally to medical devices and procedures, and more particularly to systems and methods for attaching soft tissue to bone.

Background

Complete or partial detachment of ligaments, tendons and/or other soft tissue from associated bones in the body is a common injury, particularly among athletes. Such damage is often the result of excessive pressure being applied to these tissues. For example, tissue separation can occur as a result of falls, productive activity, excessive effort during sporting events, or accidents caused in many any other situations or activities.

In cases of partial detachment, the lesion often self-heals if given sufficient time and care is taken not to re-expose the lesion to undue stress. However, in cases of complete separation, surgery may be required to reattach the soft tissue to the associated bone. There are currently a number of devices available for securing soft tissue to bone. Examples of such prior devices include screws, staples, suture anchors, and tacks. In the reattachment of soft tissue using screws, the detached soft tissue is typically moved back to the original attached bone site. The screw is then rotated through the soft tissue and into the bone, with the shank (shank) and head of the screw retaining the soft tissue against the bone. Similarly, in the reattachment of soft tissue using staples, the detached soft tissue is typically moved back to the original attached bone site. Staples are then driven through the soft tissue into the bone, with the legs and bridge of the staples holding the soft tissue against the bone.

In the reattachment of soft tissue using a suture anchor, a hole for receiving a nail is typically first drilled into the bone at the location where reattachment of soft tissue is desired. The suture anchor is then assembled into the hole using a suitable installation tool. This operation effectively locks the suture to the bone with the free end of the suture extending out of the bone. The free ends of the suture are passed through or around the soft tissue and are used to tie the soft tissue firmly to the bone.

While existing suture anchors are effective in anchoring soft tissue to bone, one drawback of existing devices is that the suture anchor must have a head that is long enough to withstand the torque exerted thereon by a driving tool (screwdriver). As a result of the increased length, the suture anchor typically extends at least partially into the underlying soft cancellous bone to seat the head below the outer surface of the bone. The bone engaging portion of the suture anchor will be primarily disposed within and engaged with cancellous bone rather than cortical bone. This is due to the fact that the cortical bone is only about 1mm to 3mm in length, whereas the head of the driver tool is often longer than 3 mm. Once implanted, the tension applied to the anchor by the suture can cause the anchor to migrate into the cortical bone causing the head of the suture anchor to bulge, resulting in poor fixation and other problems.

Accordingly, there is a need for improved methods and apparatus for soft tissue attachment to bone.

Disclosure of Invention

Methods and apparatus are provided for anchoring sutures to bone. In one embodiment, a suture anchor is provided having an elongate body with a proximal end and a distal end and a lumen extending through the elongate body. The first thread extends around the extension from the proximal end to the distal end of the extension, and the second thread extends around the extension between at least a portion of the first thread such that the first and second threads are spaced a distance apart from each other. In one exemplary embodiment, the extension has a uniform root diameter. The suture anchor may further include a suture-engaging member positioned adjacent the distal end of the extension body and arranged to allow a suture to be disposed therearound with trailing ends of the suture being capable of passing through the lumen and exiting the proximal end of the extension body.

The first and second threads can have a variety of profiles. In one embodiment, the first thread can extend from the proximal end to a location just proximal to the suture-engaging member, and the second thread can extend from the proximal end and terminate proximal to the first thread. In another embodiment, the first and second threads can extend from the proximal end to a position just proximal to the suture-engaging member such that the first and second threads have substantially the same length. Alternatively, the first thread may extend from the proximal end to the distal end, and the second thread may extend from the proximal end and terminate proximal to the first thread. In another embodiment, the first and second threads may extend from the proximal end to the distal end such that the first and second threads have substantially the same length and extend along the entire length of the extension body.

The suture anchor can also include a variety of other features. For example, the suture anchor can include a distal tip (distaltip) formed at the distal end of the suture anchor. The projection may or may not be threaded. The tip may also be blunt or pointed to facilitate insertion of the anchor into a bone hole, and may be hollow or solid. In other embodiments, the suture anchor can include a proximal end configured to receive a driver. For example, the proximal portion of the lumen may be asymmetrical or non-circular in cross-section to receive a driving tool therein.

The suture-engaging member can also have a variety of configurations. In one exemplary embodiment, the suture-engaging member extends between opposing walls of the lumen, preferably substantially perpendicular to the longitudinal axis of the lumen. The suture-engaging members can have a variety of shapes and sizes. For example, in one embodiment the suture-engaging member includes a feature, such as a scallop (small), to facilitate positioning of multiple sutures.

In yet another embodiment, a suture anchor is provided having: an extension body, first and second threads extending distally from a proximal end of the extension body; a lumen through the proximal and distal ends of the extension body; and a cutout formed in a sidewall of the extension body. The cut-out is in communication with the lumen and defines a suture-engaging member spanning the lumen and is configured such that a suture can extend around the suture-engaging member and a trailing end of the suture can pass through the hollow body.

In other aspects, a suture anchor is provided having: a hollow body, first and second threads extending from a proximal end to a distal end of the hollow body; an opening formed in a sidewall of the hollow body and in fluid communication with the lumen through the extension body; and a suture-engaging member traversing the lumen, the configuration permitting a suture to be extendable around the suture-engaging member and a trailing end of the suture to be passable through the hollow body.

An exemplary suture anchor system is also provided, which in one embodiment can include a suture anchor having: a hollow body, the first and second threads extending from a proximal end to a distal end of the hollow body; and a suture-engaging member adjacent the distal end, the suture-engaging member being contoured to facilitate passage of a suture through the suture-engaging member and to permit passage of a trailing end of the suture through the hollow body. The system can also include a driver having a distal end adapted to be inserted into and engage the proximal end of the suture anchor to thread the suture anchor into bone.

The threads may be of various configurations. In one embodiment, the second threaded distal end terminates at a location proximal to the first threaded distal end. Alternatively, the first and second threads may have substantially the same length. The suture anchor can also include a variety of other features, including those described above.

Methods of securing sutures to bone are also provided. In one embodiment, a method of securing a suture to a bone comprises: the suture is attached to the suture anchor such that the suture extends around a suture-engaging member formed in the distal portion of the suture anchor and the trailing end of the suture passes through a lumen extending through the suture anchor and out the proximal end of the suture anchor. A driver is inserted into the proximal end of the suture anchor and rotated to thread the suture anchor into the bone hole to secure the suture to the bone. In one exemplary embodiment, the suture anchor includes an opening formed in a sidewall thereof to allow fluid to flow into the inner lumen of the suture anchor. The suture anchor can include first and second threads that are axially spaced from one another and have the same pitch such that the first and second threads are threaded into bone at the same rate. In one embodiment, first and second threads can be formed on at least a proximal portion of the suture anchor such that the first and second threads engage cancellous bone. In another embodiment, the first thread can extend along the distal portion of the suture anchor such that the first thread engages cortical and cancellous bone. In another embodiment, the first and second threads can extend from the proximal end to the distal end of the suture anchor such that the first and second threads engage cortical bone and cancellous bone.

Drawings

The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1A is a side view of one embodiment of a hollow suture anchor having: a proximal portion having a double threaded region and a single threaded region, and an unthreaded distal portion having a suture-engaging member.

FIG. 1B is a perspective view of the hollow suture anchor of FIG. 1A.

FIG. 1C is a cross-sectional view of the hollow suture anchor of FIG. 1A.

FIG. 1D is another cross-sectional view of the hollow suture anchor of FIG. 1A.

FIG. 2A is a side view of another embodiment of a hollow suture anchor having: a double threaded proximal portion, and an unthreaded distal portion with a suture-engaging member.

FIG. 2B is a perspective view of the hollow suture anchor of FIG. 2A.

FIG. 3A is a side view of another embodiment of a hollow suture anchor having: a proximal portion having a double threaded region and a single threaded region, and an unthreaded distal portion having a suture-engaging member and a bone-penetrating tip (bone-penetrating tip).

FIG. 3B is a perspective view of the hollow suture anchor of FIG. 3A.

FIG. 3C is a cross-sectional view of the hollow suture anchor of FIG. 3A.

FIG. 3D is another cross-sectional view of the hollow suture anchor of FIG. 3A.

FIG. 4A is a side view of a hollow suture anchor according to another example having: a double threaded proximal portion and a single threaded distal portion having a suture-engaging member and a transfixion process.

FIG. 4B is a perspective view of the hollow suture anchor of FIG. 4A.

FIG. 4C is a cross-sectional view of the hollow suture anchor of FIG. 4A.

FIG. 4D is another cross-sectional view of the hollow suture anchor of FIG. 4A.

FIG. 5A is a side view of another embodiment of a hollow suture anchor having: a proximal portion including a double-threaded region and a single-threaded region, a threaded distal portion having a pointed tip, and a scalloped suture-engaging member.

FIG. 5B is a cross-sectional view of the hollow suture anchor of FIG. 5A.

FIG. 6 is a perspective view of one embodiment of a driver tool for inserting the suture anchor into a bone, an

FIG. 7 is a cross-sectional view of another embodiment of a driver shown engaged with a suture anchor.

FIG. 8 is a partial cross-sectional view of the suture anchor of FIG. 1A implanted in bone and having three sutures attached thereto.

Detailed Description

Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the construction, function, manufacture, use and method of the devices herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are not to be limited to the embodiments described, but only by the contents of the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.

The present invention generally provides methods and apparatus for anchoring sutures to bone. In one exemplary embodiment, a cannulated suture anchor is provided that includes a suture-engaging member formed therein or thereon to receive a suture therearound such that trailing ends of the suture can pass through the suture anchor. The use of a cannulated suture anchor allows a driver to be inserted into the lumen of the suture anchor to drive the suture anchor into bone. This configuration maximizes the bending strength of the suture anchor due to the increased engagement between the suture anchor and the driver. This, in turn, allows the suture anchor to be fabricated from a wide range of materials, including non-absorbable materials such as metals or plastics, bioabsorbable materials, and/or osteoconductive materials. The cannulated suture anchor also has the particular advantage that its inner lumen can be impregnated with bone growth promoting substances, sealants, adhesives, and the like to aid in fixation. The suture anchor may also include at least a proximal portion with double threads to optimize the fixation of the anchor in hard cortical bone, thus reducing the risk of loosening of the suture anchor. Those skilled in the art will understand that: although the methods and devices are described herein in the context of anchoring soft tissue to bone, the methods and devices may be used in a variety of other medical procedures for anchoring a wide variety of objects to one another.

FIGS. 1A-1D illustrate one exemplary embodiment of a cannulated suture anchor 10 for anchoring soft tissue to bone. As shown, the suture anchor 10 takes the form of a generally elongate body having a proximal end 10a and a distal end 10b with a lumen 10c extending therethrough. At least one bone engaging surface feature can be formed on at least a portion of the outer surface of the suture anchor 10 for engagement with bone. In the illustrated embodiment, the suture anchor 10 includes a threaded proximal portion 12a and an unthreaded distal portion 12 b. The suture anchor 10 also includes a suture-engaging member 14 disposed within the inner lumen 10c adjacent the distal end 10b of the suture anchor 10. The suture-engaging member 14 can be adapted to receive one or more sutures therearound such that the sutures can extend around the suture-engaging member 14 and trailing ends of the sutures can pass through the inner lumen 10c and bore out the distal end 10a of the suture anchor 10.

The suture anchor 10 can be constructed from a variety of materials. In one exemplary embodiment, the material has physical properties sufficient to allow the driver to be inserted into the inner lumen 10c of the suture anchor 10 and can be used to drive the suture anchor 10 into bone without damaging the suture anchor 10. Of course, the nature of the material will depend on the unique configuration of the suture anchor 10. For example, the length of the inner lumen 10c of the suture anchor 10 can maximize the bending strength of the suture anchor 10 as well as the surface contact of the suture anchor 10 with the driver, thus allowing weaker materials, such as absorbable biologic materials and/or osteoconductive materials, to be used. Those skilled in the art will understand that: a variety of other materials, including plastics and metals, can be used to fabricate the suture anchor 10.

The body of the suture anchor 10 can have a variety of configurations, shapes, and sizes. In an exemplary embodiment, the body is configured to be implanted within a bone hole drilled in bone, and more preferably is sized and shaped so that it can penetrate completely through the thickness of cortical bone. As previously noted, in the illustrated embodiment, the body has a generally elongated cylindrical shape with an inner lumen 10c therethrough. Diameter d of lumen 10c₁Can vary, but in one exemplary embodiment, the diameter d₁Sufficient to pass through one or more, preferably three, pairs of sutures. In one exemplary embodiment, the diameter d of the lumen 10c₁In the range of 1.5mm to 3.0 mm. This will allow the six trailing ends of the three sutures to pass through the lumen 10c with a maximum outer diameter of about 0.028 inches. 1A-1D, the inner lumen 10c can extend the entire length of the suture anchor 10, including through a distal tip as will be discussed in more detail below. Suture-engaging member 14 spans a portion of lumen 10c, as will be discussed in more detail below. In other embodiments, the lumen 10c may terminate before a substantially solid tip. The tip may be blunt or rounded as shown, or it may be pointed to facilitate insertion into a bone tunnel. Other tip configurations may be used, as described below or as is known in the art.

The proximal end 10a of the body can be free of a head because the hollow configuration of the body allows a driver to be inserted into the inner lumen 10c to drive the suture anchor 10 into bone. While a variety of techniques may be used to facilitate engagement between the lumen 10c and the drive mechanism, in an exemplary embodiment, the lumen 10, or at least a portion thereof, is asymmetrically shaped or non-circular, which configuration is complementary to a corresponding asymmetrical or non-circular profile of the drive tool. The asymmetric portion preferably extends along the inner lumen 10c to a length sufficient to maximize surface contact between the driver and the suture anchor 10. By way of non-limiting example, fig. 1C and 1D show a hexagonal cross-sectional shape formed in the internal cavity 10C to receive a driver tool having a corresponding hexagonal driver tool tip. The hexagonal cross-section extends from the proximal-most end 10a of the suture anchor 10 and terminates just proximal of the proximal end of the incision 16, as discussed in more detail below. Exemplary drive tools are discussed in more detail below and are disclosed in the following commonly owned patent applications: a patent application entitled "hollow suture Anchor" filed on 1.11.2006, U.S. Pat. application No. US 11/555545; the "Suture Anchor with pulley" as filed on 1/11/2006 under the name "future Anchor withPulley", U.S. patent application Ser. No. US 11/555557; and a patent application entitled "thread stitching" filed on 1/11/2006, U.S. Pat. application No. US11/555568, which is hereby incorporated by reference.

As further shown in fig. 1A-1D, the body further includes one or more bone engaging surface features formed thereon for engaging bone. While various surface features may be used, such as teeth, ridges or bumps, in one exemplary embodiment, the body may include one or more threads extending around the body, and more preferably threads formed on at least a proximal portion of the body to enhance fixation to cortical bone to prevent suture anchor migration upon implantation. As shown in fig. 1A-1D, the body includes: a threaded proximal portion 12a having first and second threads 18a, 18b extending therearound; and an unthreaded distal portion 12 b. The first thread 18a begins at the proximal end 10a of the body and terminates just proximal to the suture-engaging member 14. The particular location at which the first thread 18a terminates can vary depending on the particular configuration of the suture anchor 10 and the particular configuration of the apical process. As will be discussed in greater detail below, the illustrated suture anchor 10 can include a cut-out 22 formed in the distal end 10b thereof, and the first thread 18a can terminate just proximal of the cut-out 22. Thus, the first thread 18a extends along about 75% of the length of the suture anchor 10. However, those skilled in the art will appreciate that the length of the first thread 18a may vary. As further shown in fig. 1A-1D, the body may also include a second thread 18b extending between the first threads 18 a. The second thread 18b may extend only over a portion of the body, or may extend the entire length of the body, with or without the distal tip, as will be discussed in more detail below. As shown in fig. 1A-1D, the second thread 18b extends only along the proximal-most portion of the body, terminating in a location proximal to the first thread 18 a. The second thread 18b is thus shown extending through about 25% of the entire length of the suture anchor 10. Thus, the illustrated suture anchor 10 includes a proximal portion 12a having a double-threaded proximal region and a single-threaded distal region.

Although the position of the second thread 18b relative to the first thread 18a can vary, in one exemplary embodiment, as shown in the figures, the second thread 18b extends between the first threads 18a, and the threads 18a and 18b are spaced equidistant from one another along the axis A of the suture anchor 10, i.e., the threads 18a and 18b are axially aligned. The first and second threads 18a and 18b may have the same or different configurations, but in an exemplary embodiment the first and second threads 18a and 18b are of the same configuration and have the same shape and size, including the same pitch. This configuration allows the first and second threads 18a and 18b to simultaneously cut respective passages (paths) into the bone. Although the thread pitch can vary depending on the particular configuration of the suture anchor and the intended use, in one exemplary embodiment the thread pitch is in the range of 8TPI to 20TPI, and more preferably the thread pitch is about 15 TPI. The first and second threads 18a and 18b may also be radially aligned with one another, or the second thread 18b may be radially offset from the first thread 18a such that one of the threads (e.g., the first thread 18a) engages the bone before the other thread (e.g., the second thread 18b) to facilitate insertion.

The geometry of each thread 18a and 18b may also vary, and the threads 18a and 18b may have a constant thickness between the root and the crest, or the thickness may decrease from the root to the crest as shown. The shape of the crests may also vary. As shown in FIGS. 1A-1D, threads 18a and 18b are each of a V-shaped configuration, having opposing surfaces extending at about 40 degrees and having flat crests. This configuration facilitates engagement with bone, thereby preventing migration of the suture when the anchor 10 is implanted.

As further shown in FIGS. 1A-1D, the suture anchor 10 can have a minor diameter or base diameter dmin that is constant along the entire length of the suture anchor 10 or at least along the threaded portion. The major diameter dmax can also remain constant along the entire length of the suture anchor 10. While the particular dimensions can vary depending on the size of the suture anchor and the intended use, in one exemplary embodiment, the major diameter dmax and the minor diameter dmin of the suture anchor 10 can differ by about 1-2mm, and more preferably by about 1.5 mm. For example, the major diameter may be about 5.5mm and the minor diameter may be about 4 mm. Those skilled in the art will appreciate that the major and/or minor diameters can also vary, and that they can taper along a portion or the entire length of the suture anchor 10.

As previously explained, the suture anchor 10 can further include a suture-engaging member 14. The suture-engaging member 14 can be variously shaped, but in one exemplary embodiment is configured to engage one or more sutures that are threaded through the inner lumen 10c of the suture anchor 10. 1A-1D, the suture-engaging member 14 is a cylindrical or elongated member that traverses the inner lumen 10c between opposing inner sidewalls of the suture anchor 10. The angular orientation of the suture-engaging member 14 relative to the longitudinal axis A of the suture anchor 10 can vary, but in one exemplary embodiment, the suture-engaging member 14 is substantially perpendicular to the longitudinal axis A of the anchor 10. The position of the suture-engaging member 14 can also vary, but in one exemplary embodiment, the suture-engaging member 14 is positioned at or adjacent to the distal end 10b of the suture anchor 10. In the embodiment illustrated in fig. 1A-1D, the suture-engaging member 14 is positioned just proximal to the distal end 10b of the suture anchor 10 to form a suture-engaging groove 19 at the distal-most end of the suture anchor 10. This recessed configuration of the suture-engaging member 14 can allow sutures to be placed around the suture-engaging member 14 to be flush with the distal end 10b of the embedded suture anchor 10 or embedded into the distal end 10b of the suture anchor 10 so that the sutures do not interfere with the insertion of the suture anchor 10 into bone. The location of the suture-engaging member 14 proximate the distal end 10b also has the benefit of allowing the remainder of the lumen extending proximally from the suture-engaging member 14 to receive a driving tool. Those skilled in the art will appreciate that the suture-engaging member 14 can be integrally formed with the suture anchor 10, i.e., the suture anchor 10 and the suture-engaging member 14 can be molded from a single mold or formed from a single piece of material, or the suture-engaging member 14 can be fixedly or removably attached to the suture anchor 10.

1A-1D, to facilitate positioning of the suture about the suture-engaging member 14, the suture anchor 10 can include one or more cutouts formed in the sidewall adjacent the suture-engaging member 14. As best shown in FIGS. 1A and 1B, in one exemplary embodiment, the suture anchor 10 includes a cut-out 16, the cut-out 16 beginning at a location just proximal to the suture-engaging member 14 and encircling the distal end 10B of the suture anchor 10, such that the suture anchor 10 includes: opposed cuts or openings formed on opposite sides of the suture-engaging member 14; and a distal incision defining a suture-embedding groove 19 for placing a suture. The cut 16 can also define opposed distal arms 11a and 11b on the suture anchor 10 that are spaced apart from one another with the suture-engaging member 14 extending therebetween.

Those skilled in the art will appreciate that the unique location and configuration of the cut-out 16 may dictate the particular location and configuration of the suture-engaging member 14, as the cut-out 16 can be shaped in manufacturing to create the suture-engaging member 14. Alternatively, the particular location and configuration of the opposing arms 11a and 11b can determine the particular location and configuration of the cutout 16, as the shape and size of the arms 11a and 11b determine the shape and size of the cutout 16. The position of the suture-engaging member 14 relative to the cut-out 16 and/or the arms 11a and 11b will also determine the configuration of the distal end of the suture anchor 10, as well as whether the suture anchor 10 includes a distal recess 19 for placement of a suture.

Those skilled in the art will also appreciate that suture-engaging member 14 can have a variety of other configurations, and can be fixed or movable, such as rotatable and/or slidable. Various exemplary structures are described herein, which are described in more detail in the references of the previously cited commonly owned U.S. patent applications.

1A-1D show the second thread 18B having a length less than the length of the first thread 18a, in other embodiments the first and second threads can have the same length, and FIGS. 2A-2B show another embodiment of the suture anchor 20 having first and second threads 28a and 28B of the same length. Specifically, first and second threads 28a, 28b begin at proximal end 20a and both terminate at a location just proximal to suture-engaging member 24, or at a location proximal to cut-out 26 formed in the body. The first and second threads 28A, 28b thus extend along about 75% of the entire length of the suture anchor 20. This configuration is particularly advantageous because the double threads will improve fixation, particularly within the cancellous bone engaged by the proximal portion 22a of the anchor. The distal portion 22b of the suture anchor 20 can be unthreaded and can have the same structure as previously discussed with respect to fig. 1A-1D, or can have a variety of other structures discussed herein or known in the art.

In another embodiment, shown in FIGS. 3A-3D, the suture anchor 30 can include a pointed tip 33 to enhance penetration into bone. The distal tip 33 is shown as having a solid, pointed configuration and can comprise the distal-most end of the suture anchor 30. The suture-engaging member 34 can thus be positioned proximal to the distal tip 33, while the cut-out 36 can be a void through the opposing walls of the suture anchor 30, as best shown in FIGS. 3C and 3D. The remainder of the suture anchor 30 can be similar to that previously discussed with respect to FIGS. 1A-1D. In general, the suture anchor 30 can include first threads 38a extending from the proximal end 30a to a location just proximal to the incision 36, and second threads 38b disposed between the first threads 38a and extending from the proximal end 30a and terminating adjacent to the first threads 38 a.

Alternatively, the threads can extend along the entire length of the suture anchor. FIGS. 4A-4D illustrate another embodiment of a suture anchor 40 having a first thread 48a extending along the entire length from the proximal end 40a to the distal end 40 b. The first thread 48a thus extends towards the pointed tip 43 and may terminate at the tip 43. Second thread 48b may extend only along the proximal portion of anchor 40, as shown in fig. 4A-4D, or may likewise extend along the entire length. Those skilled in the art will appreciate that the particular configuration of the threads and the configuration of the distal tip may vary and that substantially different features may be combined to form the desired anchor. As further shown in fig. 4A-4D, in order to enable the threads 48a to extend along the distal-most portion, that is, distally beyond the cut-outs 46 and suture-engaging members 44, the cut-outs 46 and suture-engaging members 44 can be positioned closer to the middle portion of the anchor. As a result, the cut 46 passes through the thread. Also shown in Figs. 4A-4D is the minor or minor diameter D of the main body portion distal to the incision 46_rCan be smaller than the base diameter or minor diameter d of the remaining anchor proximal portion_R. This will constitute a smaller tip to embed into the bone.

Fig. 5A and 5B illustrate another embodiment of a suture anchor 50. In this embodiment, the suture anchor 50 is similar to the anchor 40, except that the suture-engaging member 54 therein is scalloped to facilitate sliding of the suture while preventing entanglement. Although the number of petals can vary depending on the number of sutures used with the anchor, in the illustrated embodiment, the suture-engaging member 54 includes two petals that define three suture-seating grooves 55a, 55b, 55 c. Thus, three sutures can be placed around suture-engaging member 54, one in each of grooves 55a, 55b, 55 c. Each suture can thus be slid individually relative to the suture-engaging member 54 without causing movement of adjacent sutures. The petals can also help keep the suture aligned as it passes through the anchor 50, thus preventing entanglement. Those skilled in the art will appreciate that a variety of other techniques may be used to help maintain alignment of the suture, prevent entanglement, and/or promote slippage. For example, the suture-engaging member can have one or more passages therethrough, each passage configured to receive a suture.

As previously noted, in use, the various suture anchors described herein can be configured to receive one or more sutures and to receive a driver to thread the anchor into bone to secure the sutures to the bone. Although a wide variety of drive tools can be used, the two exemplary embodiments of the drive tool shown in FIGS. 6 and 7 are specifically configured for use with the suture anchors described herein. Referring first to fig. 6, a driver tool 60 is shown having a generally elongated shaft with a drive head 62 at a distal end thereof. The drive head 62 is shaped and sized to correspond to the shape and size of the suture anchor. Specifically, in the illustrated embodiment, the drive head 62 has a hexagonal cross-section, which enables the drive head 62 to be positioned within and engage a hexagonal lumen formed in a suture anchor, such as the anchor 10 shown in FIGS. 1A-1D. The length of the drive head 62 can vary, but it is preferred to maximize the length to provide enhanced surface contact between the drive head 62 and the suture anchor. In one exemplary embodiment, the drive head 62 can have a length such that the drive head 62 can extend from the proximal end of the suture anchor and terminate just proximal of the suture-engaging member. As further shown in FIG. 6, the drive head 62 can further include one or more suture-seating grooves 64 formed therein that are configured to seat the trailing ends of a suture to prevent engagement of the suture between the drive head 62 and the suture anchor. Although fig. 6 shows the drive head 62 as having two opposing suture-receiving slots 64, it can include any number of receiving slots, and the shape and size of each slot can vary depending on the number of sutures to be used with the suture anchor. In another embodiment, as shown in FIG. 7, the driver 70 may be hollow so that the suture can pass through the lumen 74 of the driver 72 and through the elongate shaft of the driver, rather than extending along the outer surface of the driver 72. One skilled in the art will appreciate that a variety of other techniques may be used to facilitate engagement between the driver and the suture and to allow one or more sutures to pass freely therebetween.

The particular number of sutures to be used with the suture anchor and the driver can depend on the size of the suture anchor and driver, and in particular, the diameter of the suture anchor lumen and the size of the suture-receiving slot formed in the driver (for driver 60) or the diameter of the driver lumen (for driver 70). For example, where the suture anchor has a relatively small inner lumen, the driver may need to have a relatively small diameter and correspondingly small suture-receiving grooves (for driver 60) or a small inner lumen (for driver 70). It is therefore possible to use only one suture that is disposed about the suture-engaging member on the suture anchor with both of its trailing ends passing through either the suture-receiving slot in the driver (for driver 60) or through the lumen of the driver (for driver 70). While a single suture is sufficient to secure tissue to bone, it is preferred to use more than one suture, more preferably two or three sutures. Thus, unlike methods of increasing the size of the suture anchor and/or driver, the present invention provides various exemplary techniques for using two sutures with a suture anchor and driver configured to place only one suture. This is particularly advantageous because the suture anchor is sized to be fully embedded in cortical bone while the diameter of the suture anchor lumen and the distal tip of the driver are maximized to increase torque failure rates. This also enables the anchor to be made from a wide range of materials, including the brittle or weak materials mentioned previously.

The present invention also provides exemplary methods of anchoring tissue to bone. Although the methods described herein relate to securing soft tissue to bone, the methods described herein may be used in a variety of medical procedures for securing one structure to another. Generally, a hole is drilled in the patient's bone. The diameter of the hole is preferably slightly less than the maximum outer diameter of the suture anchor, and the length of the hole is preferably the same as or slightly longer than the length of the suture anchor. The hole will pass completely through the cortical bone to allow the suture anchor to fully engage through the thickness of the cortical bone. Depending on the length of the suture anchor, the hole may also extend into cancellous bone. One or more sutures can be attached to the suture anchor using a variety of techniques, including those described in the aforementioned commonly owned applications, and the distal tip of the driver can be inserted into the lumen of the suture anchor, as in the embodiment shown in FIG. 7. The trailing end of the suture may extend externally along the driver or through a lumen of the driver. The suture anchor can then be inserted into the bone tunnel using the driver tool. For example, for a threaded suture anchor, the driver can be rotated to thread the suture anchor into the bone hole. The threads will engage the bone hole to prevent the suture anchor from loosening. For suture anchors with a double thread, the second thread will provide for attachment fixation within the bone. By way of non-limiting example, FIG. 8 illustrates the suture anchor 10 of FIGS. 1A-1C implanted in bone B with three sutures 80a, 80B, and 80C attached. As shown, the sutures 80a-80c extend around the suture-engaging member 14 and through the inner lumen of the anchor 10 and the inner lumen of the driver 70, thus enabling the driver 70 to screw the anchor 10 into bone without interference from the sutures 80a-80 c. In other embodiments, a driver can be used to drive the bone into the bone hole and the suture anchor can be retained within the bone hole using an interference fit, a compression fit, and/or surface features (e.g., ribs or protrusions) formed on the suture anchor. Optionally, a driver may be used to drive the threaded suture anchor into the bone hole. The threads can allow for subsequent removal of the suture anchor.

Once the bone anchor is properly anchored in the bone hole, various materials (such as those previously discussed) can be introduced into or around the suture anchor by a driver tool. The driver may be removed and the trailing end of the suture may then be used to anchor the soft tissue to the bone. For example, one or both ends of the suture may be attached to a needle to allow the suture to be sutured with the needle through tissue to be anchored to bone. The suture may be sutured through tissue before or after the suture anchor is inserted into the bone. Once the soft tissue is adjacent to the bone, the suture ends can be tied off and the excess cut off to complete the procedure as is commonly done in such procedures. Once implanted, the incision extending into the inner cavity may be filled with bone growth promoting substances, sealants, adhesives, and the like to facilitate fixation.

Those skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described herein, except as indicated by the appended claims. All publications and references cited herein are incorporated by reference in their entirety.

Claims (21)

1. A suture anchor, comprising:

an extension having a proximal end and a distal end, a lumen longitudinally through the extension, a first thread extending around the extension from the proximal end to the distal end, a second thread extending around the extension between at least a portion of the first thread such that the first thread and the second thread are longitudinally spaced from one another, the extension having a constant root diameter, and

a suture-engaging member disposed adjacent the distal end of the extension body and positioned such that a suture can be placed therearound and trailing ends of the suture can pass through the lumen and out the proximal end of the extension body;

wherein the proximal end has a double-threaded proximal region and a single-threaded distal region; and

wherein the suture anchor further comprises a cut-out formed in the sidewall of the extension and communicating with the lumen, the cut-out beginning proximate the suture-engaging member and encircling a distal-most end of the suture anchor.

2. The suture anchor of claim 1, wherein the first thread extends from the proximal end to a location just adjacent the suture-engaging member, and the second thread extends from the proximal end and terminates adjacent the first thread.

3. The suture anchor of claim 1 wherein the first and second threads extend from the proximal end to a location just adjacent to a suture-engaging member such that the first and second threads have substantially the same length as one another.

4. The suture anchor of claim 1, wherein the first thread extends from the proximal end to the distal end, and the second thread extends from the proximal end and terminates at a location proximal to the first thread.

5. The suture anchor of claim 1, wherein the first and second threads extend from the proximal end to the distal end such that the first and second threads have substantially the same length as each other and extend along the entire length of the extension body.

6. The suture anchor of claim 1 further comprising: an unthreaded distal tip is formed on the distal end of the suture anchor.

7. The suture anchor of claim 1 further comprising: a pointed distal tip formed on the distal end of the suture anchor.

8. The suture anchor of claim 1 wherein the suture-engaging member extends between opposing walls of the inner lumen.

9. The suture anchor of claim 8 wherein the suture-engaging member is scalloped.

10. The suture anchor of claim 1, wherein the proximal end of the inner lumen has an asymmetric cross-sectional shape to receive a driver tool therein.

11. A suture anchor, comprising:

an extension body having first and second threads extending from a proximal end to a distal end thereof; a lumen extending into the proximal end of the extension body; and, a cut formed in a sidewall of the extension and in communication with the lumen, the cut defining a suture-engaging member spanning the lumen and configured such that a suture can extend around the suture-engaging member and a trailing end of the suture can pass through the extension; wherein the proximal end has a double-threaded proximal region and a single-threaded distal region; and

wherein the incision begins proximate the suture-engaging member and encircles a distal-most end of the suture anchor.

12. The suture anchor of claim 11, wherein the second thread has a distal end that terminates at a location proximal to the distal end of the first thread.

13. The suture anchor of claim 11, wherein the first and second threads have substantially the same length as each other, wherein the first and second threads extend from the proximal end to the distal end.

14. The suture anchor of claim 11, further comprising: an unthreaded distal tip formed on the distal end of the extension.

15. The suture anchor of claim 11, further comprising: a pointed distal tip formed on the distal end of the extension.

16. The suture anchor of claim 11 wherein the suture-engaging member is scalloped.

17. The suture anchor of claim 11, wherein at least a portion of the inner lumen has a non-circular cross-sectional shape to receive a driver therein.

18. A suture anchor, comprising:

a hollow body having a first thread and a second thread, the first thread and the second thread extending from a proximal end to a distal end of the hollow body; an opening formed in a sidewall of the hollow body, the opening in fluid communication with an interior cavity of a pass-through extension; and a suture-engaging member spanning the lumen, the suture-engaging member configured such that a suture can extend around the suture-engaging member and a trailing end of the suture can pass through the hollow body; wherein the proximal end has a double-threaded proximal region and a single-threaded distal region; and

wherein the opening begins proximate the suture-engaging member and encircles a distal-most end of the suture anchor.

19. The suture anchor of claim 11, wherein the distal end of the second thread terminates adjacent the distal end of the first thread.

20. The suture anchor of claim 11, wherein the first and second threads have substantially the same length as each other.

21. The suture anchor system of claim 11 wherein the suture-engaging member includes at least one ridge formed thereon such that the suture-engaging member is adapted to align a plurality of sutures extending therearound.