Multi-density all suture anchor

An all-suture anchor for generating bone compression and increasing interference fixation. The all-suture anchor includes a fibrous construct which is movable between a pre-deployment configuration and a deployed configuration. The fibrous construct has a first density. The all-suture anchor also includes a monofilament woven through the fibrous construct. The monofilament has a second density, which is different than the first density. The contrasting densities (i.e., irregularities) aids in the “locking” ability of the all-suture anchor by greater purchase in hard and soft bone. The all-suture anchor can have a variety of textures, barbs, and rigidities that aid in creating irregularities within the bone surface for more secure fixation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure is directed generally to an all-suture anchor and, more particularly, to an all-suture anchor composed of materials of varying densities.

2. Description of Related Art

Currently, all-suture anchors used to re-attach soft tissue to bone are generally composed of a single material having a uniform density.FIG.1shows an example of a conventional all-suture anchor1. The all-suture anchor1includes a braid2composed of a single material with a passing suture3woven therethrough for deployment. This homogenous all-suture anchor structure is relatively smooth and soft in nature. As a result, current all-suture anchors rely on expansion that is controlled by the density of the bone in addition to the mechanics of the anchor when it is deployed.

Many conventional arthroscopic all-suture anchors are set or deployed by hand. These hand-set all-suture anchors pull out of hard and soft bone more readily than all-suture anchors deployed by a driver/inserter mechanism (although, some anchors deployed by a driver/inserter mechanism pull out after being set).

Therefore, there is a need for a suture anchor made of a material(s) that is optimal for generating bone compression and increased interference fixation post-installation.

SUMMARY OF THE INVENTION

The present invention is directed to an all-suture anchor composed of a material(s) with a density (or densities) that is optimal for generating bone compression and increasing interference fixation post-installation. According to one aspect, the all-suture anchor includes a fibrous construct which is movable between a pre-deployment configuration and a deployed configuration. The fibrous construct has a first density. The all-suture anchor also includes a monofilament woven through the fibrous construct. The monofilament has a second density, which is different than the first density.

According to another aspect, the present invention includes a method for deploying an all-suture anchor. The method includes the steps of: (i) providing an all-suture anchor having a fibrous construct movable between a pre-deployment configuration and a deployed configuration, the fibrous construct having a first density and a monofilament woven therethrough, the monofilament having a second density which is different than the first density; (ii) weaving a passing suture through the all-suture anchor; (iii) loading the all-suture anchor in a pre-deployment configuration onto a driver; and (iv) driving the all-suture anchor into a bone hole using the driver. The monofilament is preferably fixed with respect to the fibrous construct after it is woven through the fibrous construct, as opposed to a passing suture that can move through the fibrous construct (at least in the pre-deployment configuration).

Suture material or sutures, as the terms are used and described herein, can include monofilament or multi-filament suture as well as any other metallic or non-metallic filamentary or wire-like material suitable for performing the function of a suture. This material can include both bio absorbable and non-absorbable materials.

Suture anchors, as the term is used herein, can include soft suture anchors and rigid suture anchors. Soft suture anchors are formed from filaments of suture material which are retained within pre-formed bone holes by being deformable to increase their diameter to a size greater than that of the bone hole, to thereby reside within the cancellous bone and under the bone cortex. One such suture anchor is disclosed in U.S. Pat. No. 9,826,971 assigned to the assignee hereof and incorporated by reference herein in its entirety. Since soft anchors are commonly made entirely of suture materials, they are sometimes called “all-suture” anchors, and generally include a fibrous construct anchor body portion (or fibrous, braided or woven fabric-type structure such as a flexible web, as described in U.S. Pat. No. 9,173,652) and a suture or filament portion. Methods and devices for inserting/deploying such all-suture anchors are known, examples of which are disclosed in U.S. Pat. No. 9,173,652.

As described in U.S. Pat. No. 8,409,252, for example, “non-soft,” “hard” or “rigid” suture anchors generally include a “hard” anchor body portion (that may or may not include inner and outer members) and a suture/filament portion. The anchor body of such suture anchors may be formed of a biocompatible and/or bio absorbable material. These materials may be of such composition that they are reabsorbed by the body, e.g., during the healing process of the bone. Exemplary materials that are suitable for use in the inner and outer members include, but are not limited to, polyetheretherketone (“PEEK”), polylactic acid/beta-tricalcium phosphate (“PLA/Beta-TCP”) composites, ultra-high molecular weight polyethylene (“UHMWPE”), as well as other metallic, non-metallic, and polymeric materials.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures, wherein like reference numerals refer to like parts throughout,FIG.2shows a top perspective view schematic representation of an all-suture anchor10, according to an embodiment. In the depicted embodiment, the all-suture anchor10comprises a fibrous construct12and a monofilament14woven therethrough. The fibrous construct12can be any fibrous, braided (e.g., uniform or non-uniform braid) or woven fabric-type structure having a first density.

In the embodiment depicted inFIG.2, the fibrous construct12is a flat length of suture having and extending between a first end16and a second end18. In alternative embodiments, the fibrous construct12can also be a tube braid or cored suture (as should be understood by a person of ordinary skill i the art in conjunction with a review of this disclosure). The fibrous construct12is movable between a pre-deployment configuration, as shown inFIG.2, and a deployed configuration, as shown inFIG.7. The fibrous construct12may be composed of any traditional suture material, such as polyethylene (e.g., UHMWPE). The fibrous construct12can be, for example, 1.5-2.5 mm in width, 0.350-0.399 mm in depth, and at least 6 inches long. In an embodiment, the fibrous construct12has, for example, a width of 2 mm and a depth of 0.37 mm. The fibrous construct12can also have, for example, an average USP knot pull strength ≥30.00 LBF, with no individual value <26.00 LBF.

Still referring toFIG.2, the monofilament14has a second density which is different (higher or lower) from the first density (i.e., density of the fibrous construct12). In an embodiment, the monofilament14can be, for example, USP #2/0 suture and is at least 6 inches in length. The monofilament14can be composed of any traditional suture material, such as nylon, for example. The monofilament14can have, for example, an average USP knot pull strength ≥4.0 LBF, with no individual value <3.8 LBF. In alternative embodiments, the monofilament14may be segmented suture of multiple densities (e.g., suture with both a second density, a third density, a fourth density . . . ), or suture joined with a length of one or more sutures having contrasting (e.g., third, fourth . . . ) densities. The monofilament14is woven through the fibrous construct12from the first end16to the second end18(although, it does not have to stretch all the way to both ends, it can exist as it is woven through between both ends). As shown inFIG.2, the monofilament14can be woven through the fibrous construct12using a needle20.

In an embodiment, the monofilament14is threaded through the needle20and the needle20is used to pull the monofilament14through the fibrous construct12to create a “baseball” stitch, for example, as shown inFIG.3. In an embodiment, the monofilament14, for example, is woven through the fibrous construct12using a whip stitching technique to achieve the baseball stitch configuration. The fibrous construct12is tensioned and the monofilament14, formed in a continuous loop, is threaded onto the needle20. The loop of monofilament14is placed around the fibrous construct12such that the fibrous construct12is extending through the loop of monofilament14.

Then, the needle20is used to puncture a first surface22of the fibrous construct12along a central longitudinal y-y axis extending through the fibrous construct12from the first end16to the second end18. The needle20is pulled through the fibrous construct12to a second surface (not shown) and the monofilament14is pulled tight such that the monofilament14is snug on the first surface22of the fibrous construct12. As a result, the first stitch24includes a first portion26of monofilament14extending from a first side28of the fibrous construct12to a first central passing location30(meaning a location near or along the central longitudinal y-y axis) and a second portion32of monofilament14extending from a second side34of the fibrous construct12to the first central passing location30, as shown inFIG.3.

After the first stitch24is placed, the loop of monofilament14extends from the bottom surface (not shown) of the fibrous construct12. To place additional stitches36, the loop of monofilament14is pulled back around the fibrous construct12. Stated differently, the fibrous construct12is pulled or extended through the loop of monofilament14again. Thereafter, the needle20is passed through a subsequent second central passing location38, spaced from the first central passing location30. The monofilament14is pulled tight, securing a second stitch36. The method is repeated to place as many stitches36as desired along the length of the fibrous construct12to create added texture or irregularities in the all-suture anchor10. Preferably, there are 6-8 central passing locations along the length of the fibrous construct12and at least 6 inches of the fibrous construct12contains woven monofilament14. In an embodiment, the first and second ends16,18of the fibrous construct12are left unstitched with monofilament14.

In accordance with other embodiments of the present invention, the stitch design does not have to look like what is shown inFIG.3. Whatever the look of the monofilament14being weaved through the fibrous construct12, it is preferable that a portion of the monofilament14extend from the outside surface of the fibrous construct12in order for an outside surface of the portion of the monofilament14to be able to grip to the surface of a bone hole upon deployment of the anchor. In addition, multiple monofilaments14of the same or different material with the same or different densities can be woven through a fibrous construct12, for added bone surface grip capability benefit.

In alternative embodiments, the all-suture anchor10comprises additional features for creating irregularity within the bone surface when the all-suture anchor10is deployed. For example, the fibrous construct12may comprise rigid, mechanical barbs (or other similar protrusions, as should be understood by a person of ordinary skill in the art in conjunction with a review of this disclosure) on an exterior surface of the fibrous construct12. In other examples, the monofilament14(or fibrous construct12) may comprise added texture or rigidity along its length (which can, but does not have to be, composed of a material of yet another different density), which creates greater interference for fixation, as shown inFIGS.5-6.

Turning now toFIGS.4-6, there are shown various views schematic representations of the all-suture anchor10loaded on a driver40. The driver40shown inFIG.4, for example, can be any standard anchor driver. In the depicted embodiment, the driver40has a pronged end42with spaced first and second arms44,46(FIG.5). To prepare the all-suture anchor10for deployment, a passing suture48is threaded through the all-suture anchor10in the pre-deployment configuration, as shown inFIGS.4-6. A first end50of the passing suture48extends from the first end16of the all-suture anchor10and a second end52of the passing suture48extends from the second end18of the all-suture anchor10.

With the passing suture48extending through the all-suture anchor, the all-suture anchor10can be loaded onto the driver40. To load the all-suture anchor10, the all-suture anchor10is placed between the first and second arms44,46of the pronged end42. The all-suture anchor10is placed in the pronged end42such that a portion of the fibrous construct12between the first and second ends16,18is placed between the arms44,46, and the first and second ends50,52of the passing suture48extend on opposing sides of the driver40, as shown inFIGS.4-6. In an embodiment, an approximately central portion54of the fibrous construct12is placed between the arms44,46.

Referring now toFIG.7, there is shown a side sectioned view schematic representation of an all-suture anchor10deployed in a bone hole56, according to an embodiment. With the all-suture anchor10in the pre-deployment configuration loaded on the driver40, as shown inFIGS.4-6, the pronged end42of the driver40is pushed into the bone hole56. When the all-suture anchor10is within the bone hole56, the driver40can be removed. The passing suture48is tensioned to deploy the all-suture anchor10. The contrasting density (i.e., irregularities) of the fibrous construct12and the monofilament14woven therethrough generates bone compression and additional interference fixation. As a result, the all-suture anchor10has additional purchase in hard and soft bone as compared to all-suture anchors composed of a single material (or multiple materials) of one density. For example, the all-suture anchor10has more power in hard bone, such as in a hip, as compared to conventional all-suture anchors (of uniform density). With the all-suture anchor10in place, the passing suture48can be used to secure a soft tissue in a desired position relative to the bone hole56. In addition, the all suture anchor10can be deployed such that the thickness of the fibrous construct12is greater in the deployed state as compared to the thickness of the fibrous construct12in an un-deployed state.