Soft tissue conduit device and method

[0001] This application is a divisional of U.S. patent application Ser. No. 11/408,282 filed on Apr. 20, 2006 now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 11/347,661 filed on Feb. 3, 2006, and issued as U.S. Pat. No. 7,749,250, and also a continuation-in-part of U.S. patent application Ser. No. 11/294,694 filed Dec. 5, 2005, and issued as U.S. Pat. No. 7,914,539, which is a continuation-in-part of U.S. patent application Ser. No. 10/984,624 filed Nov. 9, 2004, and issued as U.S. Pat. No. 7,608,098. The disclosures of the above applications are incorporated herein by reference.

[0002] Tears caused by trauma or disease in soft tissue, such as cartilage, ligament, or muscle, can be repaired by suturing and/or use of various fixation devices. Various tissue fixation devices have been developed for facilitating suturing and are effective for their intended purposes.

[0003] Although the existing soft tissue fixation devices can be satisfactory for their intended purposes, there is still a need for new devices that provide conduits for facilitating healing and promoting soft tissue vascularity.

[0004] The present teachings provide a soft tissue conduit device. The device includes an elongated body having an outer surface, the elongated body defining a plurality of longitudinal external channels, each longitudinal channel defining a conduit open to the outer surface of the elongated body, each conduit operable to conduct a biological material in soft tissue.

[0005] The present teachings also provide a method of conducting biological materials in soft tissue. The method includes inserting an elongated conduit device into the soft tissue and through a defect in the soft tissue, and conducting biological materials along at least one longitudinal channel defined on an outer surface of the conduit device into the soft tissue. The conduit device is externally threaded.

[0006] In another aspect, the method includes inserting an externally threaded elongated body in meniscal tissue. The elongated body has a plurality of external longitudinal channels. Each longitudinal channel is open to an outer surface of the elongated body and has a keyhole-shaped cross-section with a substantially circular portion and a narrow opening to the outer surface of the elongated body. Each longitudinal channel extends between a first area of the meniscal tissue having a first vascularity and a second area of the meniscal tissue having a second vascularity different from the first vascularity. The method also includes delivering biological materials from the first area to the second area through at the circular portion of the least one longitudinal channel.

[0007] In yet another aspect, the method includes passing a suture strand through a longitudinal bore of a conduit device, the conduit device having an externally threaded elongated body, the elongated body having a plurality of external longitudinal channels, coupling the suture strand to a fixation device, the fixation device inserted through a meniscal defect, and returning the suture strand through the longitudinal bore of the conduit device to form a suture loop. The method also includes inserting the conduit device through the meniscal defect such that each longitudinal channel extends between a first area having a first vascularity and a second area having a second vascularity different from the first vascularity, delivering biological materials from the first area to the second area through the longitudinal channels, and securing the suture loop with a knot.

[0008] Further areas of applicability of the present invention will become apparent from the description provided hereinafter. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention.

[0036] The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For example, although the present teachings are illustrated for repairing meniscal defects in knee surgery, the present teachings can be used to repair and facilitate healing or regeneration of any injured soft tissue.

[0037] Referring to FIGS. 1A-C, an exemplary soft tissue conduit device 100 according to the present teachings includes an elongated body 102 having an outer surface 104 and a plurality of longitudinal external channels 106 extending along the entire length of the body 102. The channels 106 are shaped such that when the conduit device 100 is inserted into soft tissue, the channels 106 can serve as conduits for conducting biological materials, such as nutrients, into the tissue from outside the tissue or between first and second areas of the tissue, such as, for example, between healthy tissue and injured or torn tissue, or between areas of different vascularity, such as between red-red (vascular), red-white (semi-vascular) and white (avascular) tissue areas of a meniscus. The channels 106 can provide a vascularity path in the tissue for facilitating healing or repair. As such, each channel 106 can have a width “w” and a depth “d” that allows the tissue to envelope or form a “tent” over the channel 106 without blocking the channel 106. Referring to FIG. 1D, deep channels 106 exemplify a shape that provides satisfactory “tenting” or draping of tissue 80 over the channels 106. Referring to FIG. 1E, shallow channels 106′ illustrate inadequate tenting of tissue 80 over the channels 106′, with the tissue at least partially entering the channels 106′. Satisfactory tenting of tissue 80 allows unobstructed or relatively unrestricted flow of nutrients or other biological materials along the channels 106. Typical aspect ratios d/w bare less than 1, such as, for example, 0.5, 0.8, etc.

[0038] Various biological materials can be delivered through the channels 106 by external cannulas or other pumping devices during or after implantation. Such biological materials can be in the form of autologous cells derived from blood or bone marrow aspirate, for example, or other appropriate exogenous biological materials. Native or endogenous biological materials can also be carried after implantation from a vascular region of the soft tissue 80 to the injured site by inserting the conduit device 100 such that the conduit device 100 extends from a vascular region of the soft tissue to the injured site. Additionally or alternatively, biological materials in the form of platelet gels can be deposited in the channels 106 before implantation, as another mechanism of biological material delivery, including nutrient, delivery.

[0039] Referring to FIGS. 1A-1C, the body 102 of the conduit device 100 can include a cylindrical portion 108 of constant dimensions and a tapered portion 110. The body 102 can also include a plurality of blunt, rounded, and generally non-cutting ridges or threads 112 that are interrupted by the channels 106. The body 102 can be cannulated with an internal longitudinal bore 114. The longitudinal bore 114 can include a plurality of facets or sides 116 for engaging a driver or other inserter for inserting the conduit device 100 in the soft tissue 80. The bore 114 can have, for example, a square, triangular, hexagonal or other shape configured to engage the driver non-rotatably.

[0040] Referring to FIGS. 1A-1C, 2A-2C, and 3A-3C, exemplary conduit devices 100 having channels 106 with rounded V-shaped cross-sections are illustrated. FIGS. 1A-1C illustrate an aspect of the conduit device 100 with four channels 106 arranged, for example, symmetrically relative to the four sides 116 of a square bore 114, although asymmetrical arrangements can also be used. FIGS. 2A-2C illustrate an aspect of the conduit device 100 with six channels 106 arranged symmetrically relative to the four sides 116 of the square bore 114. FIGS. 3A-3C illustrate an aspect of the conduit device 100 with five channels 106 arranged asymmetrically relative to the four sides 116 of a square bore 114.

[0041] Referring to FIGS. 4A-4C, an exemplary conduit device 100 having channels 106 with keyhole-shaped cross-sections is illustrated. The keyhole shape can include a substantially circular portion 118 and a narrow slot-like opening 120 to the outer surface 104 of the body 102. The keyhole shape can be used to provide a path for substantial volume of biological materials or nutrients with good tenting of tissue 80 over the channels 106. It will be appreciated, however, that a different number of channels 106 and a variety of different channel shapes can be used as conduits for the conduit device 100.

[0042] Referring to FIG. 5, an exemplary method of using the conduit device 100 is illustrated. A driver 130 can be used to insert the conduit device 100 through a tear or other defect or injury 82 in the soft tissue or meniscus 80. The driver 130 can have a shaft 132 configured to engage the bore 114 of the body 102 of the conduit device 100 to facilitate inserting and guiding the conduit device 100 into the tissue 80. The shaft 132 of the driver 130 can also include a sharp tip 134 for facilitating the insertion of the conduit device 100 into tissue 80. The driver 130 can be used to rotate the conduit device 100 such that the blunt threads 112 push the tissue 80 aside during the insertion of the conduit device 100. The conduit device 100 can be used to connect areas of good vascularity 84 of the soft tissue 80, such as, for example, the outer surface of a meniscus, with the site of the defect 82 or other areas of low or no vascularity, and can also serve as a fixation device that can bridge the defect 82 and/or bring closer together opposite sites of torn or damaged tissue at the defect 82.

[0043] Referring to FIGS. 6A-6C and 7A-7C, the conduit device 100 can have a body 102 with a substantially cylindrical shape of constant diameter without external threads or ridges, and having an outer surface 104 interrupted by a plurality of longitudinal channels 106. The body 102 can be otherwise solid (non-cannulated) as illustrated in FIGS. 6A-6C, or cannulated with an internal longitudinal bore 114, as shown in FIGS. 7A-7C. The channels 106 can have different cross-sectional shapes, including the illustrated keyhole shapes for improved tissue tenting. The non-threaded conduit devices 100 of FIGS. 6A-6C and 7A-7C can be used with various anchors, buttons, toggles or other fixation devices 140, as illustrated in FIGS. 8A-8B and 9.

[0044] Referring to FIGS. 10A and 10B, exemplary conduit devices 100 having flat or parallelepiped bodies are illustrated. The channels 106 can be square or V-shaped or U-shaped or key-hole shaped, for example. The conduit devices 100 can include central bores 114 or can be solid. It will be appreciated that conduit devices 100 of various other shapes can be used, such as oval, square, rectangular, circular, or other shapes, and having channels 106 of different shapes. The conduit devices can be coupled with fixation devices 140 using sutures or flexible strands 142 passing through the central bore 114 or through two channels 106, as discussed below in reference to FIGS. 8A-8B.

[0045] Referring to FIG. 8A, two cannulated conduit devices 100a, 100b can be coupled with corresponding fixation devices 140a, 140b using a suture or other elongated flexible strand 142. The flexible strand 142 can define a loop that passes through the first bore 114a, connects to the corresponding fixation device 140a, returns through the same bore 114a, passes through the second bore 114b, connects to the second fixation device 140b, returns through the second bore 114b, and closes the loop with a knot, button or other retainer 144.

[0046] Similarly, two non-cannulated conduit devices 100a, 100b can be coupled with corresponding fixation devices 140a, 140b using the flexible strand 142, as shown in FIG. 8B. The flexible strand 142 can define a loop that passes through a first external channel 106a of the first conduit device 100a, connects to the corresponding fixation device 140a and returns through a second channel 106b of the first conduit device 100a. The flexible strand 142 then passes through a third channel 106c of the second conduit device 100b, connects to the second fixation device 140b, returns through a fourth channel 106d of the second conduit device 100b, and closes the loop with a retainer 144.

[0047] Referring to FIG. 9, two conduit devices 100 are shown coupled with two fixation devices 140, which are inserted through a tear 82 in a meniscus and secured by tightening the loop defined by the flexible strand 142. The implantation of the conduit devices 100 and the fixation devices 140 for reducing or closing the tear 82 can be performed according to the methods described in co-pending parent patent application Ser. No. 11/347,661 filed Feb. 3, 2006, and incorporated herein by reference.

[0048] It will be appreciated from the above description that the conduit devices 100 can be used for many applications in which biological materials or nutrients are needed to be delivered to a soft tissue site or transferred from one tissue site to another. The longitudinal channels 106 of the devices coupled with dimensions that facilitate tenting of tissue provide unobstructed and continuous paths for the flow or delivery of such biological materials and nutrients.

[0049] The foregoing discussion discloses and describes merely exemplary arrangements of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.