The present disclosure relates to poly(trimethylene)terephthalate filaments and surgical or medical devices made from such filaments.
Sutures intended for the repair of body tissues have been constructed from a wide variety of materials. Sutures have been constructed from these materials, for example, in monofilament form or as multifilament structures. Filaments have also been utilized to form other surgical or medical devices, such as braided tapes, gauze, wound dressings, hernial repair meshes, vascular grafts (e.g. fabrics and/or tubes) anastomosis rings, prosthetic ligaments and tendons, growth matrices, drug delivery devices and other implantable medical devices.
While many of the existing filamentous surgical and medical devices perform satisfactorily, there remains room for improvement with respect to performance of such articles.
Poly(trimethylene)terephthalate filaments, yarns including such filaments and surgical or medical devices made from such filaments are described. In embodiments, the poly(trimethylene)terephthalate filaments are used as monofilament sutures, such as, for example, in sterile needle-suture combinations having a poly(trimethylene)terephthalate homopolymer monofilament secured to a needle. Multifilament sutures including at least one poly(trimethylene)terephthalate filament are also described.
In embodiments, yarns in accordance with the present disclosure contain at least one filament made from poly(trimethylene)terephthalate. In embodiments, the yarns described herein are heterogeneous yarns that contain one or more poly(trimethylene)terephthalate filaments and one or more filaments made from a fiber forming composition. Such heterogeneous yarns can be braided, knitted or woven to form medical/surgical devices, including, but not limited to multifilament sutures. The heterogeneous yarns alternatively can be braided into a surgical article such as a tape, or may be knitted or woven into a mesh. It is also contemplated that non-woven structures such as felt can be made to include fibers of poly(trimethylene)terephthalate.
In embodiments, methods for approximating two tissue surfaces are contemplated. In one embodiment, a method of closing a wound in tissue includes the steps of passing a suture through tissue and securing the ends of the suture to approximate the tissue, wherein the suture is made from at least one poly(trimethylene) terephthalate filament.
In another embodiment, a method of securing soft tissue to hard tissue includes providing a surgical device fabricated from first yarns and second yarns in a braided construction wherein the first yarns include at least one poly(trimethylene)terephthalate filament and the second yarns include a plurality of filaments of at least one fiber forming material; passing said surgical device through the soft tissue; securing said surgical device to the hard tissue; and manipulating said surgical device (e.g., by tying a knot in the device) to approximate the soft tissue and hard tissue.
In yet another embodiment, a method of approximating hard tissues is contemplated, wherein a multifilament surgical device fabricated from a heterogeneous braid made from a first yarn and a second yarn in a braided construction wherein the first yarn includes at least one poly(trimethylene)terephthalate filament and the second yarns include a plurality of filaments of at least one fiber forming material is manipulated to approximate the hard tissues.
In yet other embodiments, the present disclosure relates to a surgical device that includes a suture anchor having at least one suture secured thereto, the suture containing at least one poly(trimethylene)terephthalate filament.
The illustrative embodiments described herein will become more readily apparent from the following description, reference being made to the accompanying drawings in which:
Filaments in accordance with the present disclosure contain poly(trimethylene)terephthalate (referred to herein as “PTT”). PTT is a polymer having the following structure:
where n can be from about 2 to about 10000. In embodiments, the present filaments are made from PTT homopolymer having an average molecular weight of about 100,000 to about 1,000,000.
Filaments made from poly(trimethylene)terephthalate can be used in accordance with the present disclosure alone (e.g., as a monofilament) or to prepare yarns that can be incorporated into a braided, knitted, woven or other structure to provide a surgical device.
As used herein, the terms “fibers”, “filaments” and “yarns” each may be used to construct in whole or in part a surgical suture. The term “fibers”, in this context, is generally used to designate natural or synthetic structures that have a length approximately 3 orders of magnitude greater than their diameter or width. While the term “filaments” is typically used to describe “fibers” of indefinite or extreme length, and “Yarns” as a generic term for a continuous strand of twisted or untwisted “fibers” or “filaments” in a form suitable for knitting, weaving, braiding or otherwise intertwining. A plurality of yarns may be used to form a braid, knit or weave.
A “heterogeneous yarn” is a configuration containing at least two dissimilar filaments mechanically bundled together to form a yarn. The filaments are continuous and discrete, so therefore each filament extends substantially along the entire length of the yarn and maintains its individual integrity during yarn preparation, processing and use.
Unlike a heterogeneous yarn, a “homogeneous” yarn is a configuration containing substantially similar filaments. The filaments are also continuous and discrete. Therefore each filament extends substantially along the entire length of the yarn and maintains its individual integrity during yarn preparation, processing and use.
A “heterogeneous braid” is a configuration containing at least two dissimilar yarns. The two types of yarns are intertwined in a braided construction. The yarns are continuous and discrete, so therefore each yarn extends substantially along the entire length of the braid and maintains its individual integrity during braid preparation, processing and use.
In embodiments, this disclosure contemplates yarns that include at least one poly(trimethylene)terephthalate filament, articles made from such yarns, and use of such articles in surgery. Methods for forming fibers from poly(trimethylene)terephthalate are within the purview of those skilled in the art. The yarn can be a homogeneous yarn made entirely of filaments made from poly(trimethylene)terephthalate. In other embodiments, the yarn is a heterogeneous yarn made from at least one filament made from poly(trimethylene)terephthalate- in combination with a plurality of filaments made from at least one other fiber forming material. In embodiments, the heterogeneous yarn embodiments include a plurality of filaments made from poly(trimethylene)terephthalate in combination with a plurality of filaments made from at least one polymeric material that is not poly(trimethylene)terephthalate.
Some examples of fiber forming polymeric materials suitable for making filaments that may be used in combination with filaments made from poly(trimethylene)terephthalate include, but are not limited too, natural, synthetic, biodegradable, non-biodegradable and shape memory polymers. A particularly useful polymeric material may be selected from the group consisting of polyamides, polyesters, polyacrylonitrile, polyethylene, polypropylene, polyglycolic acid, polylactic acid, polydioxanone, poly(ε-caprolactone), polytrimethylene carbonate, and combinations of such materials.
Representative natural biodegradable fiber forming polymers include polysaccharides such as alginate, dextran, cellulose, collagen, and chemical derivatives thereof (substitutions, additions of chemical groups, for example, alkyl, alkylene, hydroxylations, oxidations, and other modifications routinely made by those skilled in the art), and proteins such as albumin, zein and copolymers and blends thereof, alone or in combination with synthetic polymers.
Representative synthetic polymer blocks include polyphosphazenes, poly(vinyl alcohols), polyamides, polyester amides, poly(amino acid)s, synthetic poly(amino acids), polyanhydrides, polycarbonates, polyacrylates, polyalkylenes, polyacrylamides, polyalkylene glycols, polyalkylene oxides, polyalkylene terephthalates, polyortho esters, polyvinyl ethers, polyvinyl esters, polyvinyl halides, polyvinylpyrrolidone, polyesters, polylactides, polyglycolides, polysiloxanes, polyurethanes and copolymers thereof.
Examples of suitable polyacrylates include poly(methyl methacrylate), poly(ethyl methacrylate), poly(butyl methacrylate), poly(isobutyl methacrylate), poly(hexyl methacrylate), poly(isodecyl methacrylate), poly(lauryl methacrylate), poly(phenyl methacrylate), poly(methyl acrylate), poly(isopropyl acrylate), poly(isobutyl acrylate) and poly(octadecyl acrylate).
Synthetically modified natural polymers include cellulose derivatives such as alkyl celluloses, hydroxyalkyl celluloses, cellulose ethers, cellulose esters, nitrocelluloses, and chitosan. Examples of suitable cellulose derivatives include methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxybutyl methyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, cellulose acetate phthalate, carboxymethyl cellulose, cellulose triacetate and cellulose sulfate sodium salt. These are collectively referred to herein as “celluloses”.
Representative synthetic degradable polymers include polyhydroxy acids, such as polylactides, polyglycolides and copolymers thereof; poly(hydroxybutyric acid); poly(hydroxyvaleric acid); polycarbonates; poly(amino acids); poly(hydroxyalkanoate)s, including but not limited to polyhydroxyhexanoate and polyhydroxyoctanoate; polyanhydrides; polyortho esters; poly(3-hydroxybutyric acid), poly(4-hydroxybutyric acid), poly(hydroxyvaleric acid) and blends and copolymers thereof.
Examples of non-biodegradable polymers include poly(ethylene vinyl acetate), poly(meth)acrylic acid, polyamides, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylphenol, and copolymers and mixtures thereof. A further suitable non-biodegradable fiber is ultra-high molecular weight polyethylene (UHMWPE), available under the tradename SPECTRA® (Honeywell, Inc., Morristown, N.J.) and Dyneema®/Dyneema® Pure (DSM High Performance Fibers B.V. Corporation, Heerlen Netherlands).
Rapidly bioerodible polymers such as poly(lactide-co-glycolide)s, polyanhydrides, and polyorthoesters, which have carboxylic groups exposed on the external surface as the smooth surface of the polymer erodes, also can be used.
Strands made from carbon fibers, steel fibers, shape memory alloy (e.g., nitinol) and other biologically acceptable inorganic fibrous materials can also be employed.
In embodiments polyolefin filaments are combined with filaments made from PTT. In particularly useful embodiments, the plyolefin is an ultra high molecular weight polyethylene. Ultra high molecular weight (“UHMW”) polyethylene is a linear polymer with an average molecular weight greater than about 400,000, typically in the range of about 500,000 to about 6,000,000. UHMW polyethylene has a high tenacity and low elongation to provide articles with greatly increased strength and decreased elongation.
UHMW polyethylene typically exhibits a very substantial degree of molecular orientation (95-99%) and crystalline content (60-85%), both of which contribute to the significant strength and stability of the resulting fibers. The fibers exhibit strengths from about 375 kpsi (thousands of pounds per square inch) to about 560 kpsi, and tensile moduli of about 15 msi (millions of pounds per square inch) to about 30 msi. Ultra high molecular weight polyethylene is commercially available under the trademark SPECTRA® from Allied-Signal Technologies, Petersburg, Va., and under the trademark DYNEEMA® from DSM High Performance Fibers, J H Heerlen, The Netherlands.
The filaments made from poly(trimethylene)terephthalate may make up from about 10% to about 90% of the cross-sectional area of the heterogeneous yarns, in embodiments from about 25% to 75%, and in other embodiments from about 25% to 50% of the heterogeneous yarns.
In embodiments, the heterogeneous yarns are made from poly(trimethylene) terephthalate homopolymer fibers and fibers of UHMWPE with poly(trimethylene) terephthalate homopolymer fibers being about 10 to 90% of the braid.
Sutures made in accordance with the foregoing description will exhibit superior strength and resistance to abrasion, and may find particular use in medical devices including medical devices useful in cardiac and orthopedic surgery. With respect to orthopedic surgery in particular, the suture will be useful in securing bone under high stress and abrasion as well as securing soft tissue or an implant to bone.
The filaments which form the yarns can be made using any known technique, such as, for example, melt spinning, solution spinning, gel spinning, extrusion, molding and/or solvent casting. In a preferred embodiment, the filaments can be melt spun through an extruder unit of a conventional type, such as those disclosed in U.S. Pat. Nos. 6,063,105; 6,203,564; and 6,235,869, the contents of each of which are incorporated by reference herein. The filaments of dissimilar materials can be extruded separately and subsequently brought together into a group to form a yarn, or the filaments can be extruded in a side-by-side fashion (co-extruded) and collected together to immediately form a yarn. For example, with respect to sutures, size is established according to United States Pharmacopoceia (“USP”) standards. However, each yarn can contain at least ten filaments, and often more, of at least two differing material types. The filaments run parallel to each other along the length of the yarn, although twisting and commingling the filaments to form a twisted yarn is also contemplated.
A suture 101 prepared in accordance with this disclosure can have a needle 102 attached thereto as shown in
In one embodiment, a heterogeneous yarn 10 contains a plurality of two dissimilar filaments as shown in
In another embodiment shown in
In still another embodiment shown in
In yet another embodiment shown in
Braids and/or yarns can be prepared using conventional braiding technology and equipment commonly used in the textile industry, and in the medical industry for preparing multifilament sutures. Suitable braid constructions are disclosed, for example, in U.S. Pat. Nos. 3,187,752; 3,565,077; 4,014,973; 4,043,344; 4,047,533; 5,019,093; and 5,059,213, the disclosures of which are incorporated herein by reference.
In
Illustrative flat braided structures (suitable, e.g., for tendon repair) which can be formed using the presently described yarns include those described in U.S. Pat. Nos. 4,792,336 and 5,318,575. Suitable mesh structures are shown and described, for example, in Hain et al. U.S. Pat. No. 5,292,328. In addition, filaments made from poly(trimethylene)terephthalate may be incorporated into non-woven structures, such as felt. One suitable non-woven structure is shown and described in Koyfman et al. U.S. Pat. No. 5,393,534.
If desired, surgical devices made using PTT filaments prepared in accordance with the disclosure can optionally be coated with one or more coating compositions to improve functional properties of the device. For example, a coating can be applied to improve surface lubricity and knot tie-down behavior. Suitable coating compositions include but are not limited to those disclosed in U.S. Pat. Nos. 3,867,190; 3,942,532; 4,047,533; 4,452,973; 4,624,256; 4,649,920; 4,716,203; 4,826,945; and 5,569,302, the disclosures of which are incorporated by reference herein. The coating can be applied using any known technique such as, for example coating, dipping, spraying or other appropriate techniques.
The amount of coating composition applied to the device will vary depending upon the specific construction of the device, its size and the exact material of its construction. In general, the coating composition will constitute from about 0.5 to about 4.0 percent by weight of the coated device, or higher with a preferred range from about 1.0 percent to about 3.0 percent.
A multifilament surgical device prepared from the presently described yarns (homogeneous or heterogeneous yarns) may also be impregnated or coated with one or more medicicinal/biotherapeutic substances, e.g., those which accelerate or beneficially modify the healing process when the suture is applied to a wound or surgical site. The medically useful or therapeutic agents can include varying amounts of one or more optional ingredients, such as, for example, bioactive substances such as biocidal agents, antibiotics, antimicrobials, medicants, growth factors, anti-clotting agents, analgesic, anesthetics, anti-inflammatory, antifungals, antibacterials, etc., and the like. Medicants are defined as substances which are beneficial to the animal and tend to promote the healing process. For example, a braided suture can be provided with a therapeutic agent which will be deposited/released at the sutured site. The therapeutic agent can be chosen for its wound healing properties, capability for promoting wound repair and/or tissue growth, or for specific indications such as tissue growth. Antimicrobial agents such as broad spectrum antibiotics (gentamicin sulphate, erythromycin or derivatized glycopeptides) which are slowly released into the tissue can be applied in this manner to aid in combating clinical and sub-clinical infections in a surgical or trauma wound site. To promote wound repair and/or tissue growth, one or more biologically active materials known to achieve either or both of these objectives can also be applied. Such materials include any of several human Growth factors (HGFs), magainin, tissue or kidney plasminogen activator to cause thrombosis, superoxide dismutase to scavenge tissue-damaging free radicals, tumor necrosis factor for cancer therapy, colony stimulating factor, interferon, interleukin-2 or other lymphokines to enhance the immune system, and so forth.
A suture prepared from yarns or filaments in accordance with this disclosure can also include, for example, biologically acceptable plasticizers, antioxidants, and colorants, which can be included into the composition from which the filaments making up the yarn are made or impregnated into the heterogeneous yarns of the device.
In addition, the yarn and/or product made therefrom may be plasma treated depending upon the particular needs or intended application so as to increase the handling properties of the yarn and/or product. Techniques for plasma treating are with the purview of those skilled in the art.
As noted above PTT filaments of the present disclosure can also be utilized to form other surgical or medical articles, including, braided tapes, gauze, wound dressings, hernial repair meshes, vascular grafts (e.g. fabrics and/or tubes) anastomosis rings, prosthetic ligaments and tendons, growth matrices, drug delivery devices and other implantable medical devices.
Surgical devices prepared from PTT filaments in accordance with this disclosure can be packaged and sterilized in any conventional manner known to those skilled in the art.
Once sterilized, a device, as described herein, may be used to repair wounds or secure implants located between two or more soft tissues, two or more hard tissues, or at least one soft tissue and at least one hard tissue. For example, braided multifilament surgical device is passed through, wrapped around or secured to tissue and then the tissue is approximated by manipulating the braided multifilament surgical device, such as, for example, by tying a knot, cinching the device, applying a buckle, or the like.
In a particularly useful embodiment, it is contemplated that the suture in accordance with the disclosure may be delivered in conjunction with a suture anchor delivery system and may be passed through tissue using an arthroscopic suturing instrument. Referring now to
In use during an arthroscopic procedure a cannula 300 is inserted into the joint capsule and the shaft 316 of the suture anchor delivery system 310 is inserted through the cannula 300 to a prepared site suitable to receive a suture anchor 320.
In the context of a suture anchor, a suture constructed in accordance with the present disclosure provides significantly enhanced resistance to abrasion as the suture is manipulated, including drawing the suture through the suture eyelets of the suture anchor, forming knots in the suture, and cinching the knots down tightly for secure approximation of the soft tissue to bone.
Various modifications and variations of the filaments, yarns, braids and devices and uses thereof will be apparent to those skilled in the art from the foregoing detailed description. Such modifications and variations are intended to come within the scope of the following claims.
The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/045,755, filed on Apr. 17, 2008, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
61045755 | Apr 2008 | US |