BIOACTIVE FILAMENTARY FIXATION DEVICE

BACKGROUND OF THE INVENTION

Traditional fixation devices, such as suture anchors or tissue anchors, are typically made of metal or hard plastic, and include a structure which connects or otherwise secures a filament, such as a suture, or a portion of tissue, to the body of the device. In certain applications, these devices have a diameter suitable to hold the devices within a bone. Such devices may also include additional structures to dig into the bone, such as wings, barbs, threads, or the like.

However, such traditional devices tend to be large in diameter, and must include sufficient material, or other additional structures, to withstand the forces pulling against the device, whether via a suture or directly against the device itself. The size of such devices may limit the possible implantation locations in the body, as sufficient bone mass is required to accommodate the device. Moreover, a large hole must be drilled into the bone to allow for passage of the device through the cortical layer and into the cancellous bone. The larger drill holes may be too invasive resulting in excessive loss of healthy bone, or creation of a large repair site, resulting in prolonged recovery time and higher incidence of infection and other complications.

A recent trend in fixation device technology is the “soft” device, also referred to as an “all-suture” fixation device, in which the device itself is constructed of suture-like material. Such all-suture fixation devices may provide solutions to the various problems encountered with traditional devices, as summarized above.

BRIEF SUMMARY OF THE INVENTION

The present invention concerns, generally, a soft fixation device constructed substantially of filamentary material, such as suture or other thread-like material, which is capable of providing high pull-out strength while requiring a small surgical site (e.g., bone hole) as compared to traditional fixation devices. The present invention also includes various embodiments of bioactive coatings and methods of preparation and use thereof. While the majority of embodiments disclosed herein relate to the use of the fixation device of the present invention as a suture anchor for placement in bone, other uses of the fixation device are also possible, many of which are also described herein.

In one embodiment, the present invention may include a filamentary fixation device including a filament and a sleeve, at least one of the filament and an interior of the sleeve may include a coating adapted to improve sliding of the filament through the interior. The exterior surface of the sleeve may also, or alternatively, include a coating, such as a bioactive layer, which may be adapted to allow for tissue ingrowth. The filament may also include a coating adapted to promote healing in adjacent tissue.

In another embodiment of the present invention, at least one of the filament and sleeve member may include a coating. For example, at least one of the filament and the interior may include a coating adapted to improve sliding of the filament through the interior. In addition to, or alternatively, the exterior surface of the sleeve may include a coating, such as a bioactive coating, adapted to allow for tissue ingrowth, and/or tissue ongrowth, and/or increased or accelerated bone formation and pullout strength. Further, the filament may include a coating, such as a bioactive or biologic coating, adapted to promote healing in adjacent tissue.

In a further embodiment, the present invention may include a method for securing a filament in a hole in a bone or for securing tissue to bone using a bioactive filamentary fixation device. Such a method may include: accessing the bone and preparing a bone hole; inserting a fixation device into the bone hole, the device including a bioactive sleeve member having an interior and an exterior surface along a length defined between a first end and a second end, and at least two openings positioned along the length through the exterior surface; and a filament including a first end and a second end and a length therebetween, the filament positioned relative to the sleeve member such that the filament enters through the first end and into the interior, exits the sleeve member through one of the openings on the exterior surface of the sleeve, re-enters the sleeve member through the other opening on the exterior surface and into the interior, and exits the interior through the second end of the sleeve member; pulling on the two ends of the filament to compress the sleeve member within the bone hole; adjusting the filament by pulling on at least one of the two ends of the filament; passing at least one end of the filament through the tissue; and securing the tissue to the bone by securing the filament thereto.

Further embodiments include a method for preparing a bioactive filamentary fixation device in situ including providing a filamentary fixation device including a sleeve member and a filament, providing a physiological solution such as saline, blood, bone marrow aspirate or the like, and providing bioactive material. The method may further include wetting the sleeve member (and optionally, the filament) in the physiological solution to produce a wetted sleeve (and optionally, wetted filament); and applying the bioactive material to the wetted sleeve (and optionally, wetted filament) to coat the sleeve and produce a bioactive filamentary fixation device in situ that can be secured in a hole in bone or used for securing tissue to bone.

The step of applying the bioactive material may include dipping, rolling, mixing or the like the wetted sleeve member in the bioactive material to coat the sleeve member (and optionally, filament) or to incorporate the bioactive material into the sleeve (and optionally, filament). The step of applying the bioactive material may also include covering the sleeve and filament with the bioactive material.

In yet a further embodiment, the present invention can include a method for making a bioactive fixation device in situ including: providing a fixation device including a sleeve and a filament, providing a physiological solution such as saline, blood, bone marrow aspirate or the like, providing bioactive material, combining the physiological solution with the bioactive material to produce a mixture, and applying the mixture to the sleeve to coat the sleeve, thus producing a bioactive filamentary fixation device at the time of surgery in situ that is secured in a hole in bone or used for securing tissue to bone as described in the methods above.

The step of applying the mixture may include dipping, rolling or mixing to coat the sleeve and filament or to incorporate the mixture into the sleeve and filament. The step of applying the mixture may also include covering the sleeve and filament with the mixture.

The bioactive material is preferably bioactive glass particles provided in a size range from about 5 microns (μm) to about 500 μm microns, or from about 5 μm to about 250 μm and more preferably in a size range of 25 μm to 150 microns. The bioactive glass may be provided in a glass vial or other such container or apparatus. In some embodiments, the bioactive material may alternatively be a calcium salt, or combination of materials such as bioactive glass, calcium salt, allograft bone, demineralized bone matrix (DBM), proteins, growth hormones and the like.

The present invention also provide for kits for facilitating methods as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of a fixation device of the present invention.

FIG. 2 illustrates the fixation device of FIG. 1 after tensioning of the filament 20.

FIG. 3A illustrates one embodiment of a method of insertion of the fixation device of FIG. 1, wherein the fixation device is positioned within a hole prepared in a bone; FIG. 3B illustrates the fixation device of FIGS. 1 and 2, in which the filament 20 is tensioned and the fixation device is compressed; and FIG. 3C illustrates potential migration of the fixation device proximally, towards the cortical bone.

FIG. 4 illustrates one embodiment of a method of insertion of the fixation device of FIGS. 1 and 2, in which an insertion tool is used to implant the fixation device within a hole prepared in a bone.

FIG. 5 illustrates another embodiment of a fixation device of the present invention.

FIG. 6 illustrates the fixation device of FIG. 5 after tensioning the filament 120.

FIGS. 7A-C illustrate a further embodiment of a fixation device of the present invention.

FIGS. 8A-B illustrate an alternative configuration of the fixation device of FIGS. 7A-C.

FIGS. 9A-C illustrate yet another embodiment of a fixation device of the present invention.

FIGS. 10A-C illustrate another embodiment of a fixation device of the present invention.

FIGS. 11A-C illustrate a further embodiment of a fixation device of the present invention.

FIGS. 12A-C illustrate an additional embodiment of a fixation device of the present invention.

FIGS. 13A-C illustrate yet another embodiment of a fixation device of the present invention.

FIGS. 14A-C illustrate a further embodiment of a fixation device of the present invention.

FIGS. 15A-C illustrate still another embodiment of a fixation device of the present invention.

FIGS. 16A-C illustrate another embodiment of a fixation device of the present invention.

FIG. 17 illustrates one embodiment of the bioactive filamentary fixation device of the present invention.

FIGS. 18A-B illustrate graphical representations of the in vivo performance of the bioactive fixation device of FIG. 17 via μCT bone density evaluations.

FIGS. 19A-B illustrate graphical representations of the in vivo performance of the bioactive fixation device of FIG. 17 via histological analyses.

FIG. 20 is a schematic illustration of another embodiment of a bioactive filamentary fixation device where the sleeve is provided with pockets to contain a bioactive coating.

DETAILED DESCRIPTION

The fixation device, and associated systems, kits and methods, of the present invention are intended for use in tissue, such as bone or soft tissue. Soft tissue may be, for example, meniscus, cartilage, ligaments and tendons, or the like. While many of the exemplary methods disclosed herein are directed towards its use as a suture anchor for implantation into a bone hole, other uses, some of which are described herein, are also envisioned. As used herein, “proximal” or “proximally” means closer to or towards an operator, e.g., surgeon, while “distal” or “distally” means further from or away from the operator. The term “coat” and iterations thereof, as used herein, means to cover a structure, integrate with a structure or envelop a structure. Further, as used herein, “coat” and iterations thereof encompasses partially coating, substantially coating, or completely coating an underlying structure, and thus is intended to encompass different degrees of coverage of a structure.

In a first embodiment, illustrated in FIGS. 1 and 2, the fixation device 10 of the present invention includes a sleeve member 11 and a filament 20. Such a fixation device is disclosed in commonly owned U.S. application Ser. No. 13/303,849, filed Nov. 23, 2011, the entirety of which is incorporated by reference herein as if fully set forth herein. One example of such a fixation device 10 may be the ICONIX® line of tissue anchors (Stryker Corporation, Kalamazoo, Mich.). The sleeve member 11 includes an interior 15 and an exterior surface 16, both of which extend along a length defined between a first end 14 and a second end 13. The sleeve member 11 may be substantially hollow. The exterior surface also includes at least two openings 12c, 12d positioned along the length of the exterior surface 16, each of which form a passageway through the exterior surface and into the interior 15. As illustrated, though, the exterior surface may include more than two openings, and may include four openings (for example, 12a, 12b, 12e, 12f), six openings (for example, 12a, 12b, 12c, 12d, 12e, 12f), or any other number of openings in any configuration positioned along the length of the exterior surface. The various openings 12 may be prepared, for example, during the weaving process forming the sleeve 11 or, alternatively, the openings may be formed after the sleeve has been woven, such as by the use of a needle, knife, or other tool capable of forming the openings.

The filament 20 includes a length and at least a portion of the length of the filament is positioned within the interior 15 of sleeve 11. The filament also includes first and second free ends 21, 22. The filament is slidable within the interior 15. The filament may also pass through at least one of the openings 12 along the exterior surface 16 of the sleeve 11. For example, as in FIG. 1, filament 20 may exit the interior 15 through opening 12c and re-enter the interior through opening 12d.

In one embodiment, the fixation device 10 of the present invention may include a sleeve member 11 including an interior 15 and an exterior surface 16 along a length defined between a first end 14 and a second end 13, and at least two openings 12 positioned along the length and extending from the interior and through the exterior surface; and a filament 20 including a first free end 22 and a second free end 21 and a length therebetween, the filament positioned relative to the sleeve member such that the free ends extend from the sleeve member at the first and second ends of the sleeve member, the filament being disposed inside the interior from the first end 14 to a first opening 12a, outside the sleeve member from the first opening to a second opening 12b, and inside the interior from the second opening to the second end 13 of the sleeve member. The sleeve member may further be substantially hollow, may be provided with a bioactive coating, may contain at least one pocket 17′″ (see FIG. 20) to hold bioactive materials or may be made bioactive in situ as discussed further below. Such pockets may be formed in the material of the sleeve 11′″ or, if the sleeve is a braided filamentary structure, the pockets may simply be small spaces or openings within the braid, or small crevices within which bioactive materials may be positioned.

Put another way, in one embodiment, the present invention may include a fixation device including a sleeve member including an interior and an exterior surface along a length defined between a first end and a second end, and at least two openings positioned along the length and extending from the interior and through the exterior surface; and a filament including a first end and a second end and a length therebetween, the filament positioned relative to the sleeve member such that the filament enters through the first end into the interior, sequentially exits and re-enters the sleeve member through consecutive openings on the exterior surface of the sleeve, and exits the interior through the second end of the sleeve member such that the filament is disposed outside of the sleeve member in X regions along the length of the sleeve member, is disposed inside the interior in X+1 regions along the length or the sleeve member, and passes through openings numbering 2X times, wherein X≧1. The various exemplary embodiments illustrated in this application show that, for example, X=2 (as in FIGS. 5-6, for example); X=3 (as in FIGS. 1-4, 7-13 and 16, for example); X=4 (as in FIGS. 14A-C, for example); X=5 (as in FIGS. 15A-C).

The filament 20 may be, for example, a length of suture or other such material. The filament may be substantially hollow or substantially solid, and may further have a substantially round or substantially flat (e.g., tape) shape. The filament may also include, for example, a relatively stiff portion, relative to the rest of the filament, which can provide beneficial uses such as for simpler threading through small devices, such as a fixation device like a ReelX suture anchor (Stryker Corporation, Kalamazoo, Mich.), or to provide a stiff portion which may be pushed through a cannula or other instrument, such as a suture passer. The sleeve 11 may also be, for example, a suture or other such material that is substantially hollow forming the interior 15. The sleeve, like the filament, may also include a stiff portion or portions which may provide for better placement on an inserter, such as by helping the sleeve to fold around the end of the inserter. Both the sleeve and the filament may be constructed by known means, such as by braiding multiple filaments together, as is the normal manufacturing process of sutures and the like. Either or both of the filament and sleeve may be constructed of synthetic material (e.g., PLGA, UHMWPE, or the like) or of organic material (silk, animal tendon, or the like).

The filament 20 may also optionally include at least one indicating marker 17a, 17b, 17c and 17d which may indicate to an operator, such as a surgeon, whether or not the device is properly positioned and/or compressed, as will be explained in greater detail below. The indicating marker may be, for example, a spot (as illustrated), a radial ring, a portion having a differing color from the rest of the filament, or the like. In another example, the indicating markers 17a-d of the filament 20 may be a portion of the filament 20 being of a different color than the rest of the filament. In this example, the portion of filament 20 between reference numbers 17a and 17b, and between 17c and 17d, may be of a different color than the remainder of the filament 20. Such contrasting colors of these portions may provide a clear indication to the operator when performing a surgical procedure, and may be of particular use in arthroscopic procedures.

Further, the filament 20 may also include a color or other pattern along its length. For example, the filament 20 may be of a certain color such that an operator may know which suture, among numerous others which may be present at the surgical site, is the filament 20. Moreover, filament 20 may have multiple colors or patterns along its length, other than those represented as the at least one indicating marker. For example, one half of the filament 20 may be one color, and the other half of the filament may be a different color. If the particular surgery requires that the two ends of filament 20 be tied together, such as by a slip knot, the two different colors may assist the operator in knowing which half of the filament should be used as the post and which half should be used to tie the slip knot around the post. Such a decision would be based on the particular surgical procedure being performed. Of course, the two differing colors may cover different amount of the length of the filament, however, the differing colors may be most useful if they cover at least the two free ends or end portions 21, 22 of the filament such that an operator can easily differentiate between the two lengths of the filament.

The sleeve has a diameter at least as large as the filament such that the sleeve has an inner diameter of sufficient size to allow the filament to pass therethrough and be slidable therein. Various arrangements of sizes of filament and sleeve are envisioned, so long as the filament remains slideable through the sleeve. For example, in one embodiment, the filament 20 may be a #2 suture while the device 10, positioned on an inserter, may have a diameter of about 1.2 mm. In one exemplary use of the device, where the device is positioned within a bore hole in tissue, such as bone, this sized device 10 may be positioned within a bore hole in tissue having a diameter of about 0.8-1.6 mm, preferably about 1.20-1.45 mm. In an alternative embodiment of the device 10, two filaments 20 may be included within a single sleeve 11, where the filaments are both #2 suture and the device 10, positioned on an inserter, may have a diameter of about 1.8-2.6 mm, and preferably about 1.9 mm. This sized device may also be positioned, for example, within a bore hole in tissue having a diameter of about 1.5-3.0 mm, preferably about 1.9-2.3 mm. This size of a bore hole may also be used for an alternative embodiment of the device 10 including three filaments 20 within a single sleeve 11. During use, the sleeve, being a length of filamentary material, may stretch or otherwise expand such that the effective diameter of the sleeve may be larger than the examples provided above. Of course, many other configurations of filament and sleeve sizes are envisioned depending on the surgical location and procedure.

Additionally, the sleeve is flexible and is further expandable and compressible which may allow the sleeve, upon tensioning of the filament to, for example, adjust from a substantially U-shape (e.g, FIGS. 1, 3A) and compact or crush, or otherwise compress, to a substantially W-shape (e.g., FIGS. 2, 3B-C). As the sleeve compresses, the diameter of the sleeve may increase and the height of the sleeve may decrease. This shape change during compression provides for increased pullout strength as the sleeve further engages the cancellous bone and/or cortical bone in this compressed shape, as seen for example in FIGS. 3B-C.

The pullout strength may also depend on the positioning of the openings 12 along the sleeve, and particularly, the positioning of the middle openings, which are positioned toward the base of the U-shape, prior to compression of the sleeve, and which, during compression, assist in forming the W-shape of the sleeve. For example, as to the embodiment of FIGS. 1-4, the openings 12c and 12d may be spaced apart at a distance such that at least 3 mm of filament spans the distance between the openings 12c, 12d, and more preferably, at least 6 mm of filament span the distance between the openings 12c, 12d. Such distance between openings 12c, 12d may allow for a larger amount of sleeve material to be present between the openings, such that as the sleeve is compressed, this larger amount of material creates a W-shape, as in FIG. 3B-C, which may affect an increased pullout strength of the device. If less than 3 mm of filament spans between openings 12c, 12d, there will also be less sleeve material between the openings, which may result in decreased pullout strength due to less material forming the middle of the compressed W-shape. Moreover, as discussed in greater detail below, the span of filament, outside of the sleeve, between openings 12c and 12d may allow for better seating on an insertion device 30 (FIG. 4) such that, for example, the device 10 may fit through a smaller bore hole in a tissue than if the filament were positioned within the sleeve between openings 12c and 12d.

Similarly, the openings near the ends of the sleeve, for example, openings 12a, 12f of FIG. 1, may be positioned at least 3 mm from the ends 13, 14 of the sleeve to maintain sleeve strength. If the openings 12a, 12f are placed too close to the ends, such as less than 3 mm away from the ends, the sleeve may break during compression, which may result in decreased pullout strength. In the event that the sleeve is provided with a bioactive layer or coating, or bioactive pocket, increased pullout strength may also be attributed to the bonding of the bioactive material with the surrounding tissue.

The fixation device is constructed, in one embodiment, by weaving two separate filament-like structures, the sleeve 11 and the filament 20, using known materials (such as sutures or the like) in a specific weaving process. In one example, a needle (not shown) may be used to pass the filament (attached to the needle) through the interior 15 of the sleeve, from the first end 14 to the second end 13. The filament may be directed through the various openings 12 through the sleeve 11 and finally be pulled out through the second end 14. Following assembly, the fixation device 10 is now ready for packaging, sterilization, and subsequent use. In order to allow for proper sliding of the filament 20 through the sleeve 11, the filament may be passed through the interior of the sleeve such that the filament does not overlap itself, as can be seen in the various embodiments illustrated in the figures. As can also be seen in the various figures, in order to allow for the sliding of the filament 20, the filament is passed through the interior of the sleeve member in a single direction along the length of the sleeve member. Such configurations of the sleeve and filament may provide decreased friction between the sleeve and filament such that the filament has an increased ability to slide, even when the sleeve is compressed.

Sliding of the filament 20 within the sleeve 11 may be improved through the introduction of a coating on at least one of the interior 15 of the sleeve and the filament 20. Suitable coatings may include PTFE or the like which minimizes friction between the filament and the sleeve and improves sliding.

Other coatings may also be applied to at least one of the filament and sleeve. For example, the exterior surface 16 of the sleeve 11 may have a coating suitable for allowing tissue ingrowth. Such a suitable coating may be hydroxyapatite powder or tricalcium phosphate for promoting bone ingrowth. Other coatings may include collagen-based additives, platelet-rich plasma, bioactive glass, or the like, to be used depending on the type of tissue into which the device 10 is being placed.

In certain embodiments, the present invention is a bioactive filamentary fixation device where the fixation device is made bioactive in situ. The completed bioactive fixation device is illustrated in FIG. 17. Specifically, the sleeve 11′ and/or at least a portion of filament 20′ of the fixation device is wetted or submerged in physiological solution such as saline, blood, bone marrow aspirate, platelet rich plasma, solution containing stem cell suspensions, including mesenchymal stem cells, other biological or biologically compatible solutions, or the like at the time of surgery, and the wetted sleeve is then rolled, dipped or mixed with bioactive material, preferably at least bioactive glass particles, to coat the sleeve, thus producing a bioactive fixation device in situ. As defined above, such coating technique may result in partial coating, substantial coating, substantially total coating, a total coating, or any degree of coating therebetween, of the sleeve and/or filament.

In other embodiments, the fixation device is made bioactive in situ by providing a fixation device including a sleeve and a filament; providing a physiological solution such as saline, blood, bone marrow aspirate, platelet rich plasma, solution containing stem cell suspensions, including mesenchymal stem cells, other biological or biologically compatible solutions, or the like at the time of surgery; providing bioactive material; wetting or otherwise soaking the sleeve and/or filament in the physiological solution; and applying the bioactive material to the sleeve and/or filament, thus producing a bioactive fixation device in situ.

The step of applying the bioactive material to a wetted sleeve and/or filament may include dipping, rolling, mixing or the like the wetted sleeve in the bioactive material to coat the sleeve and/or filament or to incorporate the bioactive material into the sleeve and/or filament. The step of applying the bioactive material may alternatively include covering the sleeve and/or filament with the bioactive material, such as by submerging. In one exemplary alternative embodiment, the physiological solution is first combined with the bioactive material to create a mixture, and the mixture is subsequently applied to the sleeve and/or filament.

The bioactive material is preferably bioactive glass particles provided in a size range of from about 5 microns (μm) to about 500 μm, or from about 5 μm to about 250 μm and more preferably in a size range of 25 μm to 150 microns. The bioactive glass may be provided in a glass vial or other such container or apparatus.

In addition to bioactive glass, the bioactive material/coating may include a calcium salt such as calcium phosphate, tricalcium phosphate, beta-tricalcium phosphate, hydroxyapatite or any combination thereof. In certain embodiments, the bioactive coating includes bioactive glass particles such as 45S5 or Combeite and tricalcium phosphate.

In some embodiments, the bioactive material may be a combination of materials such as bioactive glass, calcium salt particles, allograft bone particles, demineralized bone matrix (DBM) particles, polymeric particles, proteins, biomolecules, anti-microbial agents, biological agents, growth hormones or the like. In such embodiments, a vial or apparatus could be used to contain the bioactive glass particles, calcium salt particles, or various combinations of materials as described above. Regardless of whether the bioactive material is a single material or a combination of materials, it is preferred that all of the bioactive material be provided in a size range of from about 5 microns (μm) to about 500 μm, or from about 5 μm to about 250 μm and more preferably in a size range of 25 μm to 150 μm.

In some embodiments, the fixation device includes a bioresorbable sleeve comprised of materials such as collagen or polycaprolactone. The bioresorbable sleeve may then be further coated with the bioactive material/coating as described herein.

In some embodiments, the fixation device includes a bioresorbable sleeve made of or containing bioactive material or bioactive glass. The bioactive material or glass may be incorporated into the sleeve material in addition to being coated on the surface of the sleeve.

In another embodiment, as illustrated in FIG. 20, the sleeve 11′″ is designed to contain at least one pocket 17′″ for containing or retaining bioactive particles to enhance or increase the loading or coating capacity of the device.

In still other embodiment, the coating may be enhanced with biologics or compounds, such as growth factors, cells, anti-microbial, biofilm disruptive agents, osteoporosis drugs, or a combination thereof.

The present invention also provide for kits for facilitating methods as described herein.

The device 10 may be positioned on an inserter 30 which may assist an operator in positioning the device within a bone hole. The inserter 30 may include a distal end 31 on which the device 10 is positioned. The distal end 31 may be a blunt end, as illustrated in FIG. 4. Alternatively, the inserter distal end may be a forked end, such that the sleeve nests within the fork, or may have an active clamping structure, similar to a forceps or the like, which can optionally engage or disengage the sleeve 11 as needed. Of course, the distal end 31 must have a sufficiently small size to maintain the usefulness of the small diameters of the fixation device, and the intended benefit of the device being implanted into a smaller diameter bone hole, particularly when the fixation device is to be implanted using an arthroscopic technique.

Furthermore, as illustrated in FIG. 4, this embodiment of fixation device may provide for better loading onto an inserter due to at least the relationship between the sleeve and the filament between openings 12c and 12d. Specifically, because the filament is outside the sleeve between these openings, the device may be more easily loaded onto the inserter because the sleeve and filament can be stacked atop one another. Additionally, for example, such a setup may allow the operator to prepare an even smaller tissue hole for implantation of the device 10 since the device, between openings 12c and 12d, has an even smaller diameter than, for example, other embodiments, such as for example the embodiment of FIGS. 5 and 6, where the filament 120 is inside the sleeve between openings 112b and 112c, such that the sleeve and filament are instead, effectively, a single larger structure.

As mentioned above, other embodiments of the fixation device may include a single sleeve having two or more filaments positioned within its interior. In one example of a sleeve having two filaments positioned therethrough, a first filament may, similar to filament 20 of FIG. 1, pass through the various openings of the sleeve. The second filament, however, may either also pass through the openings of the sleeve, or stay within the interior of the sleeve along the entire length of the sleeve. In a further example, where three sutures are positioned within a single sleeve, the first filament may pass through the sleeve, and openings, therein, as illustrated in FIG. 1. The second filament may either stay entirely within the interior of the sleeve along the length of the sleeve or may also pass through the openings of the sleeve, as in FIG. 1. The third filament may also either stay entirely within the interior of the sleeve along the length of the sleeve or may also pass through the openings of the sleeve, as in FIG. 1. Of course, further alternative arrangements are envisioned, including, for example, arrangements where one of the filaments only passes through a couple of the openings present in the sleeve.

In use, one embodiment of which is illustrated in FIGS. 1-3, the sleeve 11 may be used in a method of anchoring a filament 20 in a bone. Using a drill and drill guide (not shown), such as that found in U.S. application Ser. No. 12/821,504, filed Jun. 23, 2010, the entirety of which is incorporated by reference herein as if fully set forth herein, or other drill and drill guide known in the art, a drill hole 51 is prepared in bone 50 where it is desired to anchor a filament 20. The drill and drill guide may include a laser etching, or similar marking, or alternatively a hard stop between the drill and drill guide, to ensure proper drilling depth. For example, the hole may be prepared in the shoulder joint to repair labral tissue which has separated from the glenoid. The diameter of the hole may be, for example, about equal to the diameter of the sleeve itself, such that, the device, folded on itself, will compress and fit snuggly within the bone hole, even prior to deployment of the device, as will be discussed below. Thus, for example, for a 1.2 mm sleeve, the drill hole may have a diameter of about 1.2 mm, and for a 1.8 mm sleeve, the diameter of the drill hole may be about 1.8 mm. Such matching of drill hole to device diameter may create a press-fit connection between the device the bone hole, providing initial contact between the device and the bone, prior to deployment of the device. The depth of the drill hole is dependent on the particular anatomy in which the device is to be implanted, but the depth may be, for example, typically between about 13-25 mm. In any event, the drill hole should pass through the cortical bone and enter into the cancellous bone 52. It should be noted that, if a straight guide, as is known in the art, is used, then these measurements should be used, depending on the size of the sleeve. However, if a curved guide is used, such as the above guide incorporated by reference, then the operator may, optionally, wish to make the bore hole slightly larger to ensure placement of the sleeve completely into the bore hole upon exiting the curved guide. As discussed below, upon deployment of the device, sufficient contact between the bone hole and the device may still be achieved to attain required pullout strength.

Once the hole is prepared, the drill is removed from the drill guide, and the drill guide may remain firmly in place at the bone hole. The device 10, positioned on an insertion tool 30, may then be passed through the drill guide (not shown) and to the hole in the bone, as illustrated in FIG. 4, for example. The sleeve 11 is then pressed into the bone hole, with the filament 20 positioned through the interior as illustrated, and may optionally be placed in the bone hole by lightly malleting using a mallet or like instrument to firmly seat the sleeve in the bone hole. Optionally, the inserter may have a laser etching, or other marking, which may assist the operator in accomplishing a proper insertion depth into the bone hole. At this point in the procedure, as illustrated in FIGS. 3A and 4, the device 10 is substantially folded in half within the bone hole, such that the two halves contact the bone hole side walls along a portion of their length. Such initial contact may achieve a press-fit engagement between the bone hole and the device such that the device is frictionally engaged by the bone hole which may provide initial friction to maintain the device within the bone hole, particularly, as below, when the inserter 30 is being removed from the bone hole. As in FIG. 3A, the fixation device may be placed as deeply as possible into the bone hole such that a portion of it may contact the floor of the bone hole. While not necessary, such placement may allow for maximum room for any potential upward migration of the fixation device within the bone hole.

Once the bone hole has been prepared, and the fixation device is positioned within the bone hole, the fixation device may then be deployed. As illustrated in FIGS. 3A and 3B, the inserter tool has been removed from the drill guide by pulling the inserter directly back through and out of the guide. The operator may then grasp the ends 21, 22 of the filament 20 which are extending from sleeve 11. Optionally, these filament ends may be removeably secured to the handle (not shown) of the inserter for ease of locating and for organizational benefits. The operator then may tension the ends of the filament 20, which may be accomplished with a single, continuous pull on the filament ends, to compress and set the sleeve 11 within the hole in the bone such that the sleeve compresses from its U-shape of FIG. 1 towards the W-shape of FIG. 2. Such compression occurs from the bottom of the U-shape upwards, as in FIGS. 3A-B, such that the bottom of the U-shape compresses towards the ends 13, 14 (although some downward compression of the ends 13, 14 towards the bottom of the U-shaped sleeve may also occur). Such compression may, as illustrated for example in FIG. 3A, lift the sleeve 11 from the floor of the bone hole. Further tensioning on the filament ends 21, 22 may result, as illustrated in FIG. 3C, in migration of the fixation device 10 proximally within the bone hole and towards the cortical bone 50. Such proximal migration of the fixation device may result in even further compression of the sleeve 11 as well as additional frictional engagement with the bone hole walls. In a further example, the sleeve 11 may migrate proximally until it contacts the underside of the cortical bone layer 50, such that the sleeve 11 may be prevented from further movement, e.g., out of the bone hole, by its engagement against the underside of the cortical bone layer. Such engagement may create additional resistance against pullout.

The operator may then verify that the sleeve 11 is set in the bone hole, by performing a tug on the filament ends 21, 22, and may additionally verify that the filament 20 can still slide through the sleeve 11 by pulling on one of the ends 21, 22. The filament 20 should still be slideable through sleeve 11, even when the sleeve is compressed, in order to perform manipulation of the filament 20 in order to, for example, gather and/or pierce tissue to thereby secure tissue to, or adjacent to, the implantation site. For example, such ability to manipulate the filament after deployment of the sleeve is important in rotator cuff surgery as the filament must be manipulable to properly reattach the cuff tissue back to or adjacent to the implantation site.

Alternatively, when tensioning the filament ends 21, 22, rather than pulling both ends simultaneously until the device is completely deployed, the operator, while holding both ends to prevent sliding of the filament, may instead pull on the ends sequentially, such that first, one of the ends 21 or 22 is pulled, and subsequently, the other of the ends 22 or 21 is pulled, to deploy the device.

In another alternative, where the filament includes indicating markers 17a-d, the operator may use such markers as a guide in confirming proper deployment has occurred. As illustrated in FIGS. 1 and 2, markers 17a-d are initially positioned along the length of the sleeve, prior to deployment. As the filament ends 21,22 are pulled, to deploy the device, the markers 17a-d are pulled proximally, towards the operator, along with the filament ends. As illustrated, the sleeve 11 may also migrate proximally during this step. As the proximal markers 17a, 17d pass above the cortical bone 50, they may indicate to the operator that the device has properly deployed. The operator may continue to pull on the ends of the filament until fully deployed (e.g., the filament does not move proximally any further using typical pulling force on the filament ends). However, upon this subsequent pulling, if the distal markers 17b, 17c are exposed above the cortical bone surface 50, then they may indicate that the implant is very close to being pulled out of the bone and the operator should decide if the resistance they feel is adequate or if they would prefer to pull the implant out completely and attempt the procedure again.

In any event, as the filament ends are pulled and the device is deployed, the sleeve resists pullout from the bore hole due to the friction against the cancellous bone 52 surrounding bone hole 51, and such friction is increased as the sleeve is compressed further, as well as if the sleeve migrates proximally (and particularly if the sleeve contacts the underside of the cortical bone layer). Moreover, as the sleeve is compressed, the forces applied to the sleeve may also be transferred to the surrounding cancellous bone, as illustrated in FIGS. 3B-C. Such affect on the cancellous bone may create additional friction and thus anchorage for the sleeve in the bone hole, to resist potential pullout. Further, as the device compresses and further engages the walls of bone hole 51, the surrounding cancellous bone 52 may interdigitate with at least a portion of the sleeve to provide added anchorage of the device within the bone hole. Such interdigitation may include, for example, cancellous bone protrusions overlapping and/or passing between the filaments of the sleeve to engage the sleeve. Moreover, the compressed sleeve, as discussed above, may migrate and engage the underside of the cortical surface, and may through such migration compress even further, and in this more compressed shape will result in a very strong structure to resist being pulled out the small hole in the cortical bone, as illustrated in FIG. 3C.

In another alternative of this method, the insertion tool 30 may also remain within the bone hole during deployment (not shown), to assist in maintaining the sleeve within the bone hole as the filament ends are pulled and the sleeve is compressed.

Following deployment of the device 10, with the sleeve 11 and filament 20 fixedly secured within the bone hole, the device may achieve pullout strengths comparable to traditional metal and polymeric devices despite this device 10 being constructed solely of suture or like filament material. For example, the embodiment of FIGS. 1-4, utilizing #2 suture in a foam block, achieved pullout strengths of at least 60 lbf, though higher pullout strengths are likely depending on the strength of the underlying bone, the diameter of filament 20, and other such variables. Similarly, using the embodiment of FIGS. 1-4, with the addition of a second filament 20, of #2 suture, woven through sleeve 11, a pullout strength of at least 65 lbf was recorded prior to the test foam block fracturing.

In accordance with this embodiment of a method of use, the sleeve 11 is anchored in bone, thus securing the filament 20 to the bone, while still allowing the filament to be slidable through the sleeve. Such ability to maintain the filament in a sliding association to the sleeve, even after the sleeve has been compressed, is important in shoulder and hip surgery, among other surgeries, because the operator may require an adjustable suture length to secure soft tissue at the repair site adjacent to the hole in the bone. This is especially important in arthroscopic surgery because sliding knots are frequently used to secure tissue that is accessed through a cannula. Such sliding association is maintained at least in part by the setup of the filament relative to the sleeve in that the filament passes through the sleeve only once and in a single direction. For example, the filament enters from one end of the sleeve, passes in and out of the plurality of openings in sequential order along the length of the sleeve, and then exits out the second end of the sleeve. Thus, as the sleeve compresses to form a W-shape, as in FIG. 2, the various openings in the sleeve tend to align adjacent one another such that the filament maintains, substantially, a U-shape, and thus can slide through the ends and the openings along the length of the sleeve regardless of the shape of the sleeve.

In one example of the device 10 of FIGS. 1-4, the force required to slide the suture through the deployed sleeve was measured, following a deployment force, applied by tensioning of the ends of the filament, of about 12 lbs. Once the sleeve was deployed (e.g., in the W-shape), between about 1.75-2.75 lbf was required to slide the filament through the sleeve. Of course, alternative embodiments of filaments and sleeves may result in different sliding forces needed to manipulate the filament through the sleeve.

The present invention may also be used, in another embodiment, in a method of securing a tissue to a bone. After the filament has been tensioned and the sleeve anchored in the bone, as in the above embodiment of the method of securing a filament to bone, the filament may then be used to secure tissue to a reattachment site located on the bone at or adjacent to the bone hole. In one embodiment, the filament may be used to reattach rotator cuff tissue, and thus the filament may be manipulated to engage and/or collect the cuff tissue and may be tied or otherwise secured to hold the tissue at the reattachment site. For example, one end 21 or 22 of the filament may be pulled through the tissue (using a needle or the like) and be used to pull the tissue to the reattachment site at or adjacent to the bone hole, at which point the other end of the filament may be incorporated to tie the tissue to the reattachment site, or the like. Other potential tissues on which this method may be used includes at least a portion of a shoulder labrum, at least a portion of a hip labrum, or the like.

In a further embodiment, the fixation device of the present invention may be used in a method of repair of soft tissue, such as a meniscus, ligament or tendon, or the like, wherein such methods do not require that the device 10 be deployed within a bone hole 51. Instead, the device, as to these methods, would function similar to a button anchor for use in, for example, ACL repair, such as is disclosed in U.S. patent application Ser. No. 12/682,324, now U.S. Published App. No. 2011/0125189, filed Oct. 9, 2008 and assigned to the same assignee as this application, the entirety of which is incorporated by reference herein as if fully set forth herein. The device may also serve as a button anchor for use in, for example, meniscus or cartilage repair, such as is disclosed in U.S. patent application Ser. No. 12/550,069, now U.S. Published App. No. 2009/0312792, filed Aug. 28, 2009, the entirety of which is incorporated by reference herein as if fully set forth herein.

In terms of, for example, a ligament or tendon repair, such as an ACL repair, where a tissue graft is secured within a bone tunnel, the device 10 may, following preparation of the bone tunnel by known means, be passed up through the tunnel, using an inserter such as inserter 30. In this embodiment, at least the distal-most portion of the tunnel (e.g., the lateral side of a femur) may have a diameter which allows the undeployed device, as illustrated in FIG. 1, to pass through the tunnel but not the deployed device, as illustrated in FIG. 2. Once the device exits from the bone tunnel, and is thus positioned on the lateral side of the bone (e.g., femur), the filament ends 21,22, which remain outside the opposite end of the bone tunnel, may be pulled to deploy the anchor. The deployment of the anchor may compress the sleeve 11 in a manner, as in FIG. 2, which inhibits the sleeve from passing back through the tunnel. The filament ends may then be tied or otherwise maneuvered to engage the ACL graft, which may then be placed within the bone tunnel as is known in the art. Thus, the device 10 may act as an anchor against which a graft may be tensioned to complete the repair.

In terms of, for example, the repair of a soft tissue tear such as in a meniscus or cartilage mass, where the tear is to be approximated to promote healing of same, the device 10 may be passed through the tissue mass, through the tear, and through a side surface of the tissue. In this embodiment, the inserter 30 may include, for example, a needle tip or other structure capable of forming a pathway through which the device, in the undeployed configuration as in FIG. 1, may pass. Once the device is positioned outside the side surface of the tissue, the filament ends, which remain in position on the opposite side of the tissue, may be pulled to deploy the sleeve 11. Once the sleeve is deployed, the sleeve is thus too wide to fit back through the pathway. The filament ends may then be tied or otherwise maneuvered to approximate the tear, which is positioned between the sleeve and the filament ends. The filament ends may then form a knot, or otherwise secure to one another, against the opposite side of the tissue. Thus, the device 10 may act as an anchor against which the filament ends may be tensioned to approximate the tear in the soft tissue to complete the repair.

Alternatively, these methods may also be used to secure a bone to hard tissue, such as another bone, as in a syndesmosis repair. In such a method, the filament may, as above, pass through the other bone (e.g., through a bone throughhole) or may pass around the other bone to effect a reattachment of the two bones to one another to promote healing of the injured joint. Thus, upon activation of the device, the filament ends may then engage the other bone and be tied together to secure the two bones together. Such methods of use may be utilized in the repair of bone in the ankle joint or in the acromioclavicular joint.

As illustrated in FIGS. 5 and 6, another embodiment of fixation device 110 includes a sleeve member 111 and a filament 120. The sleeve member 111 includes an interior 115 and an exterior surface 116, both of which extend along a length defined between a first end 113 and a second end 114. The sleeve member 111 may be substantially hollow. The exterior surface also includes at least two openings 112b, 112c positioned along the length of the exterior surface 116, each of which form a passageway through the exterior surface and into the interior 115. As illustrated, in this embodiment, the exterior surface may include four openings (for example, 12a, 12b, 12c, 12d), though any other number of openings in any configuration along the length of the exterior surface may be present.

This embodiment also includes a filament 120 having a length and at least a portion of this length is positioned within the interior 115 of sleeve 111. The filament is slidable within the interior 115. The filament may also pass through at least one of the openings 112 along the exterior surface 116 of the sleeve 111. For example, as in FIG. 5, filament 120 may exit the interior 115 through opening 112a re-enter the interior through opening 112b, exit the interior once again through opening 112c, and re-enter the interior through opening 112d.

Comparing FIG. 5 with the first disclosed embodiment, in FIG. 1, it is apparent that the filament 120 remains inside the interior at the bottom portion (between openings 112b and 112c), while the filament 20 is outside of the interior at the similar bottom portion (between openings 12c and 12d) in FIG. 1. In addition to the aforementioned differences in width of the device upon placement on an inserter, these differing configurations may provide different forces on the sleeve as the filament 20, 120 is tensioned to compress the sleeve. For example, in FIG. 1, as the filament 20 is tensioned, openings 12c and 12d may be pulled towards one another such that the sleeve between these openings may be pinched or crushed to form the W-shape. In FIG. 5, however, the tensioning of filament 120 may provide an upward force at openings 112b and 112c, thereby moving the portion of the sleeve between these openings up towards the first and second ends 113, 114 which may form the W-shape. Thus, these two exemplary embodiments illustrate two different relationships of a sleeve and a filament, either of which may result in a compressed sleeve capable of securing a filament within a bone hole.

The fixation device embodiment illustrated in FIGS. 5 and 6 may be used in similar methods of use as illustrated in FIGS. 3 and 4 and as discussed above.

In further alternative embodiments, which also may be used in similar methods of use as illustrated in FIGS. 3 and 4 and as discussed above, the sleeve and filament may have a relationship which results in the sleeve, upon compressing, attaining a compressed shape other than the W-shape discussed above. For example, as illustrated in FIGS. 7A-C, the sleeve 211 may have a U-shaped starting shape (FIG. 7B), but upon compressing, may attain a clover shape (FIG. 7C). Similar to the embodiments discussed in detail above, the openings 212a-f of this embodiment likewise, upon compression, may move towards one another, e.g., opening 212a and opening 212b are adjacent one another, and even contacting one another, upon compression of sleeve 211. Moreover, in this closer shape, the filament 220 may still have a generally U-shaped arrangement, within the clover shape of sleeve 211, such that the filament 220 may still slide within the sleeve 211.

FIGS. 8-16 illustrate other exemplary shapes which the sleeve may attain upon compressing. As illustrated, the various shapes depend on a variety of factors including but not limited to the number of openings along the length of the sleeve, the location of the openings along the sleeve, the relationship of the filament relative to the sleeve, and the shape of the openings on the sleeve. The pullout strength and capability of being used in the above disclosed methods may be similar to the embodiment disclosed in FIGS. 1-4. It should be noted that in all of the embodiments disclosed in this application, particularly those in FIGS. 7-16, upon compression, the sleeve may not always attain the same shape each and every time. For example, the shape and size of the bone hole may force the sleeve into a different shape, upon compression, than those illustrated herein. Also, in another example, the exact dimensions and locations of the openings through the sleeve may be altered slightly which could result in an alternative shape of the sleeve upon its compression.

For example, in FIGS. 8A-B, the relationship of the sleeve 211′ and filament 220′ is the same as the relationship illustrated in FIG. 7A, except that when the device 210′ is curved into the U-shape of FIG. 8A, the filament 220′ exits outside the sleeve 211′ on the outside of the U-shape, e.g., between openings 212a′ and 212b′. By contrast, the filament 220 illustrated in FIG. 7B, upon exiting the sleeve 211, exits on the inside of the U-shape, e.g., between openings 212a and 212b. While FIGS. 7B and 8A appear to be quite similar, the two different relationships may result in drastic differences once the sleeves are compressed, as illustrated in FIGS. 7C and 8B, which illustrate alternative shapes of compressed sleeves.

In yet another example of such differences, FIGS. 9A-C illustrate another alternative embodiment of a relationship of a sleeve 311 and a filament 320 forming an device 310. In this embodiment, openings 312a and 312b are radially offset from one another, and the filament 320 must be twisted around the outside of the sleeve to reach between opening 312a and opening 312b. Upon folding of the sleeve 311 (FIG. 9B), the openings 312a and 312b remain radially offset to one another, and filament 320 twists around sleeve 311 such that it may pass through the openings 312a and 312b. Such a relationship may result in yet another alternative shape of the sleeve upon compressing during deployment of the sleeve. Again, it should be observed, that the filament, upon compression of the sleeve, substantially maintains a U-shape, within and around the sleeve, such that sliding of the filament remains possible.

In some embodiments, as in FIGS. 1-8, the filament, when positioned within the interior of the sleeve, may extend in a generally longitudinal path along the length of the sleeve such that the filament and sleeve are substantially parallel with one another. Using FIG. 7A as an example, filament 220 is generally positioned axially along the length of the sleeve 211 while entering and exiting the interior of the sleeve via openings 212 which are positioned along the length of sleeve 211 and generally in series—one after the other—along the length.

In an alternative example, however, the filament may be generally transverse to the interior of the sleeve, when the filament is positioned within the interior. For example, such a relationship is variously illustrated in FIGS. 9-16. As illustrated clearly in FIGS. 14A-C, for example, the filament may pass through opening 812b, travel transversely through the interior, and out opening 812c. Such a relationship of the filament and sleeve is also shown as to openings 812d and 812e, and 812f and 812g. As shown, however, the filament may still remain substantially parallel to the interior of the sleeve at the ends of the sleeve, e.g., between end 813 and opening 812a and end 814 and opening 812h, such that the filament exits from the interior at the first and second ends. This is similar to other embodiments herein. Such a relationship may provide for better sliding of the filament through the sleeve.

Such embodiments having a generally transverse configuration when the filament passes through the sleeve as FIGS. 9-16 may result in alternative shapes of the sleeve when compressed. As in the other embodiments described above, the shape of the sleeve when compressed will depend on the number of openings along the length of the sleeve, the location of the openings along the sleeve, the relationship of the filament relative to the sleeve, and the shape of the openings on the sleeve.

In yet another alternative, the filament and sleeve may be in a hybrid configuration whereby the filament, along at least a first portion of its length other than at the ends of the sleeve, is substantially parallel to the interior of the sleeve, and along at least one other portion, may be generally transverse to the interior of the sleeve. Such variations are illustrated in FIGS. 13A-C. Thus, in this type of relationship, the filament is again generally parallel to the sleeve at the ends of the sleeve (between end 713 and opening 712a and end 714 and opening 712f). The filament and sleeve are also generally parallel between opening 712c through openings 712d and 712e and on to opening 712f and end 714. The filament is transverse to the sleeve from opening 712b to 712c.

The various embodiments illustrated in the figures provide many examples of the device of the present invention. While the relationship between the filament and sleeve varies from embodiment to embodiment, each of the embodiments have similarities such as, for example: the filament and sleeve are generally parallel to one another at the ends of the sleeve such that the filament exits from the ends of the sleeve; the sleeve and filament can be moved to a U-shape, prior to deployment of the device, and loaded onto an inserter; and with the sleeve compressed, the filament generally maintains a U-shape such that it may remain slideable through the sleeve even when the sleeve is compressed.

These various embodiments result in a smaller device than those presently in public use because the filament only passes through the interior of the sleeve once along its length, remains within the sleeve and exiting through the ends of the sleeve, and, in many embodiments, is outside the sleeve at the location where the inserter tip holds the device, resulting in a generally smaller diameter of the device. The smaller sized device allows for a smaller hole to be prepared in the bone, and a smaller access port to the bone, which results in a smaller surgical site in the patient.

Moreover, in the event the device does pull out from the bone post-surgery, since the device is made entirely of a filament-like material, such as suture, the device would not lacerate adjacent anatomy within the patient, which is a concern if a traditional device pulls out from the bone.

The present invention may also include various kits and systems which include at least one of the device embodiments above. For example, in one embodiment, the present invention may include a system including a device, including a sleeve and filament, and an inserter. The system may be packaged individually, and even sold separately, such that the surgeon may place the device on the inserter. Alternatively, the device may come pre-installed on the inserter, within a single package, such that the surgeon may remove the system from the packaging and immediately use the system and install the device within a bone hole.

In another embodiment, such a system may further include the aforementioned drill guide and drill, which may come pre-packaged as an entire system or which may be sold separately and later combined by the surgeon and used for the above discussed methods of use.

In another embodiment, the present invention may include a kit which includes a plurality of devices, each having a sleeve and filament, and an inserter. The plurality of devices may be any combination of the above devices. For example, the plurality of devices may include more than one of the device disclosed in FIGS. 1-4, wherein the sleeve of each device has a different diameter and/or length than the other sleeves of the other devices. Alternatively, the sleeve of each device may have a different number and/or positioning of openings, such that the appropriate device may be selected which will provide the desired pullout strength or compression properties (which may be dependent on the anatomy in which the device is implanted, the condition of the bone in which the device is implanted, or the like). Alternatively, the plurality of devices may include various devices of the above embodiments, or other similar devices, from which a surgeon may select from based on the specifics of the surgical site, pullout strength required, and the like.

Such kits may further include a plurality of drill bits which may be matched with a device, selected from the plurality of devices, to prepare an appropriately sized bone hole for insertion of the device.

Any other suitable combination is also envisioned for the above systems and kits which may be useful or desirable to a surgeon. For example, the various components of the systems or kits may all be available to a surgeon a la carte, such that a unique system or kit may be created for a particular surgeon dependent on the needs or desires of the particular surgeon. In addition, a kit for preparing a bioactive fixation device may include a filamentary fixation device and a vial of bioactive material, bioactive glass and/or tricalcium phosphate particles, and a syringe for aspirating physiological solution (the tray may be used to mix all of the components together to make a bioactive filamentary fixation device in situ).

Example 1
Pre-Clinical Evaluation of a Bioactive Filamentary Fixation Device

A pre-clinical study was conducted in six sheep to evaluate the effectiveness of a bioactive filamentary fixation device prepared in situ in comparison with non-bioactive fixation devices. Micro-CT (μCT) (bone density) and histological analyses were performed. The sheep were divided into two groups: three were placed in the 2-week time period group and three were placed in the 6-week time period group. Surgeries were performed bilaterally using a transcortical, medial approach with four anchor sites drilled per leg. The sites were filled with four different fixation device types creating a total of n=6 of each sample per time period. The samples included: 1) filamentary fixation device alone; 2) filamentary fixation device prepared in situ with fresh sheep blood; 3) filamentary fixation device prepared in situ with fresh sheep blood and tricalcium phosphate; and 4) filamentary fixation device prepared in situ with fresh sheep blood and bioactive glass (bioactive filamentary fixation device of the present invention). For each sample group, an ICONIX 25, 2 strands #5 Force Fiber was used as the base filamentary fixation device.

The samples of the present invention (e.g., group 4), were prepared in situ by soaking the filamentary fixation device in fresh sheep blood obtained at the time of surgery. After the devices were wetted, they were covered in bioactive glass (size range) by dipping/rolling the wetted fixation device in the bioactive glass particles in the operating room. The bioactive filamentary fixation device samples were then inserted into respective drilled holes of the sheep bone, along with one sample from each of the other groups per leg (e.g., each sheep leg contained one of each of the four samples outlined above). fixation device

Upon sacrifice at 2 weeks and 6 weeks, samples were analyzed using μCT prior to performing histological analyses. Results are shown in FIGS. 18-19.

The present invention provides a simple, point of care method for making a bioactive filamentary fixation device in situ. It was found that the present invention bioactive fixation device accelerated early bone formation and increased bone density around the device.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

BIOACTIVE FILAMENTARY FIXATION DEVICE

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