Abstract:
An apparatus and method for delivering or installing a surgical suture or suture-like implant into soft tissue, such as the meniscus of the knee, for example, for reattachment or repair of that tissue. The apparatus and method facilitate ease of placement of the suture or implant by the surgeon, protect surrounding tissue and nerves from damage during use, and permit suturing to occur through a single body portal. An injury to soft tissue, such as a tear in the meniscus of the knee joint or detachment of soft tissue from bone, is repaired through a single body portal by installing a surgical suture across the injury, tear, or detachment and passing that suture back through the body portal so that the suture can be joined and the injury, tear, or detachment can be reapproximated by the surgeon while working through the single body portal.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to surgical devices and procedures and, more particularly, to an apparatus and method for suturing or repairing soft tissue injuries such as, for example, tears in the meniscus of the knee. 
     BACKGROUND OF THE INVENTION 
     The meniscus is the intra-articular cartilage found in the joint that separates the femur from the tibia, that is, the knee joint. Proper functioning of the knee joint depends, in part, upon the meniscus&#39;ability to provide the joint with biomechanical stability and shock absorption during ambulation. Frequently, the meniscus is injured or torn, causing joint instability, pain in the knee, and resultant difficulties in ambulation. Two common surgical techniques are used in an effort to alleviate the pain associated with this type of injury. The first of these techniques is referred to as a menisectomy, which is the removal of the piece of tissue that has torn away from the greater meniscus. Depending upon the severity of the tear in the meniscal tissue, the surgeon may regard this as the best surgical option for the patient. The second technique involves the installation of a surgical implant into the segments of torn meniscal tissue to promote the fusion of the tissue and facilitate normal healing of the injury. In many cases, the surgeon will regard this latter option as more desirable than the former, since it is far less radical and potentially has fewer degenerative consequences, such as the development of osteoarthritis, for the patient over time. 
     Presently known devices and methods for delivering a surgical suture or suture-like implant into the meniscus or other soft tissue for repairing a tear in that tissue are unsatisfactory in several regards. Specifically, the prior art devices and methods may frequently prolong otherwise elegant surgical procedures by imparting the procedure with unnecessary mechanical inefficiencies. For example, the inability of prior art devices to pass suture or implant material into and out of soft tissue through the same body portal necessitates that a plurality of incisions be made into a patient&#39;s body, thereby increasing the level of trauma experienced by the patient during the procedure. Additionally, prior art rotating suture or implant feeding mechanisms employ counter-intuitive methods of operation that require the surgeon to rotate the wheel mechanism in a direction that is opposite the direction in which the surgeon desires to feed the suture or implant material. Moreover, currently known devices are incapable of accommodating variably dimensioned suture or implant materials, thereby presenting the surgeon with two equally undesirable options: First, the surgeon must use a single suture or implant material having a particular diameter or thickness, regardless of the needs of the patient; or, second, the surgeon must employ a plurality of surgical instruments, each capable of accommodating particularly dimensioned suture or implant material, which necessarily increases the number of steps required to complete the procedure and likely prolongs its duration. 
     In view of the foregoing, a need exists for an improved apparatus and method for repairing an injury to soft tissue which overcomes the shortcomings of the prior art. Thus, there is a need for an apparatus and method which enable a surgeon to pass a suture or other generally elongated implant material into and out of injured, torn, or detached soft tissue in essentially the same direction. There is also a need, especially in the case of arthroscopic surgeries, for an apparatus and method which are capable of passing a suture or implant material into and out of a joint space through a single body portal, thereby reducing the number of incisions required to accomplish the procedure. There is also a need for a single apparatus which is capable of delivering sutures or implant materials of various diameters or thicknesses. There is also a need for an apparatus having a rotating suture or implant feeding mechanism that permits the surgeon to rotate the feed mechanism in the same direction that the surgeon desires the suture or implant material to be fed. There is also a need for an apparatus capable of passing a plurality of tissue-piercing devices and suture legs through soft tissue at one time. There is also a need for an apparatus which can selectively orient the suture or implant material in either a horizontal, vertical, or diagonal direction, depending upon the needs of the patient and/or the desires of the surgeon. There is also a need for an apparatus and method for passing a suture or implant through soft tissue and grasping the end of the suture or implant on the opposite side of the soft tissue. Additionally, there is a need for an apparatus and method for passing a needle through a body portal and to the site of soft tissue injury while also protecting the surrounding tissue and nerves from damage that can be caused by the passage of that needle. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus and method for delivering or installing a surgical suture or suture-like implant into soft tissue, such as the meniscus of the knee for example, for the reattachment or repair of that tissue. The apparatus and method of the invention facilitate ease of placement of the suture or implant by the surgeon, protect the surrounding tissue and nerves from damage during its use, and permit all suturing to occur through a single body portal. The present invention can be used in either open or arthroscopic surgical procedures and can be used for any tears in the meniscus or for other injuries to soft tissue which require a suture or implant to be passed through the tissue to facilitate reapproximation and healing of that tissue. In accordance with the invention, an injury to soft tissue, such as a tear in the meniscus of the knee joint or detachment of soft tissue from bone, is repaired through a single body portal by installing a surgical suture across the injury, tear, or detachment and passing that suture back through the body portal so that the suture can be joined and the injury, tear, or detachment can be reapproximated by the surgeon while working through the single body portal. It should be understood that the device of the instant invention can be used to pass suture or suture-like implants equally effectively. Thus, wherever the terms “implant” or “implant material” are used herein, it should be understood that the principles of the present invention apply equally to the use of all manner of surgical suture or suture-like materials. 
     The apparatus of the instant invention includes a guide structure which can be inserted through a body portal and brought into proximity with particular soft tissue. The guide structure is suitably configured to guide a length of suture or surgical implant material through the soft tissue and to bring legs of the length of implant material into proximity with each other. The guide structure includes a suitable, selectively moveable, tissue-piercing device, such as a needle for example, capable of piercing soft tissue and of being withdrawn from the soft tissue so that suitable suture or implant material then can be fed through the guide structure and into the soft tissue. The guide structure further is configured to be withdrawn toward the body portal and from the body in a manner which causes the guide structure to become disengaged from the length of implant material while leaving the length of implant material extending through the soft tissue and the legs of the length of implant material in proximity with each other. This then permits the surgeon, at his or her discretion, to join the approximated portions of implant material to accomplish the repair or reattachment of the soft tissue. However, it should be understood that the present invention does not require that the portions of the length of implant material be joined, nor is the present invention limited or restricted in any way to the joining of these portions of implant material. 
     In an exemplary embodiment of the instant invention, the guide structure further includes a pair of guide portions supported in spaced apart relation to each other and defining a gap which enables soft tissue to be disposed between the guide portions; a tissue-piercing device moveable in the gap between the guide portions and configured to pierce soft tissue disposed in the gap between the guide portions; and an introducer moveable in opposite directions in the gap between the guide portions. The introducer is moveable in one direction to form a passageway in the gap for guiding a length of implant material through soft tissue disposed within the gap and also is moveable in an opposite direction for re-establishing the gap between the guide portions. Thus, the gap that has been re-established between the guide portions enables the legs of the length of implant material to pass through the gap as the guide structure is withdrawn toward the body portal. The guide portions are suitably configured to guide the legs of the length of implant material into proximity with each other as the guide structure is withdrawn from the surgical site and toward the body portal. 
     In another exemplary embodiment of the present invention, the apparatus further includes a selectively engageable force applying device for feeding the suture or implant material from the proximal end of the guide structure to the distal end of the guide structure. The force applying device feeds suture or implant material through the guide structure by selectively engaging a length of implant material and thereby driving the length of implant material through the guide structure. The force applying device can also selectively disengage from the length of implant material to enable the length of implant material to slide more freely within the guide structure, as when the guide structure becomes disengaged from the length of implant material and is withdrawn from the body portal for example. 
     Other objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It should be understood, however, that the detailed description and specific examples, while indicating exemplary embodiments of the present invention, are given for purposes of illustration only and not of limitation. Many changes and modifications within the scope of the instant invention may be made without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS AND EXHIBITS 
     The features and advantages of the instant invention reside in the details of construction and operation as more fully depicted, described, and claimed hereinafter; reference being had to the accompanying drawings and exhibits forming a part hereof, wherein like numerals refer to like parts throughout and wherein: 
     Exhibit 1 is a computer generated model of the human knee shown from the anterior aspect; 
     Exhibit 2 is a computer generated model of the superior aspect of the meniscus and the tibial plateau; 
     FIG. 1 is a side view of an exemplary embodiment illustrating the major components of the device; 
     FIG. 2 illustrates the tissue-piercing device of the embodiment of FIG. 1; 
     FIG. 3 illustrates the introducer tube of the device of FIG. 1, including an implant feeding mechanism and an introducer tube handle having a threaded member for attaching the introducer tube handle to the guide structure handle of FIG. 4; 
     FIG. 4 illustrates the assembly of the guide structure, including the guide tubes and the guide tube handle, wherein the guide tube handle has a female threaded portion adapted to attach the introducer tube handle of FIG. 3; 
     FIGS. 5-14 illustrate a method of using the embodiment of FIG. 1 to repair a torn meniscus; 
     FIG. 15 illustrates the guide tubes of another exemplary embodiment of the device having a plurality of introducer tubes and guide tubes which enable a plurality of tissue-piercing devices to pass through torn tissue simultaneously; 
     FIG. 16 is a detailed view of the device of FIG. 15 illustrating the distal end of the device and cross sectional views of the guide tubes; 
     FIGS. 17-23 illustrate a method of using the device of FIGS. 15 and 16, wherein a plurality of tissue-piercing devices can be passed through torn tissue simultaneously; 
     FIG. 24 is a detailed cross sectional view of the feeding mechanism located on the introducer tube handle of FIG. 3; 
     FIG. 24A is a top view of the feeding mechanism of FIG. 24; 
     FIG. 25 illustrates another exemplary embodiment of the implant feeding mechanism located on the introducer tube handle; 
     FIGS. 26 and 26A illustrate exemplary embodiments of the device having alternative orientations or bends in the guide structure which facilitate manipulation of the device around anatomical structures of the body; 
     FIG. 26B is an isometric view of the device of FIG. 4 defining the directions referred to herein; 
     FIGS. 27,  27 A,  27 B,  27 C, and  27 D illustrate another exemplary embodiment of the device, wherein a receiver has a plurality of moveable elements for receiving and retaining a length of implant material guided through segments of torn soft tissue; 
     FIGS. 28,  28 A, and  28 B illustrate another exemplary embodiment, wherein a tissue-piercing device connected to a length of implant material is retained by a receiver formed by a plurality of flexible biased members; 
     FIG. 29 illustrates yet another embodiment of the device, wherein a plurality of tissue-piercing devices can pierce segments of torn tissue and allow a length of implant material to pass from a guide tube set, through segments of torn tissue, through a channel device, back through the tissue, and then into another guide tube set, in a manner which delivers a vertical stitch through the segments of torn tissue; 
     FIGS. 30 and 30A illustrate yet another embodiment of the device which allows a plurality of tissue-piercing devices to pass through segments of torn tissue and permits a length of implant material to pass through the torn tissue twice, in a manner which delivers a horizontal stitch through the segments of torn tissue; 
     FIG. 31 illustrates an exemplary embodiment of the device superimposed on a top cross-sectional view of a meniscal tear; and 
     FIG. 32 is a diagram depicting a lateral view of the knee and illustrating the use of the exemplary embodiment of the device shown in FIG. 1 to repair the meniscus. 
    
    
     DETAILED DESCRIPTION 
     The present invention is an apparatus and method for delivering or installing a surgical suture or suture-like implant material into soft tissue, such as the meniscus of the knee for example, for the reapproximation or reattachment of that tissue. The device is particularly useful for repairing torn or detached intra-articular tissue, such as the meniscal cartilage of the knee joint, and can be used in either open or arthroscopic surgical procedures. It should be understood that the instant invention is not limited to the use of surgical suture. The present invention includes the use of other implants or implant materials, as now known in the art or may be designed in the future, which may have similar physical or chemical properties to surgical suture but are better able to promote fixation and healing of soft tissue. Wherever the terms “implant” or “implant materials” are used herein, it should be understood that these terms mean all manner of surgical suture or suture-like materials, including, without limitation or restriction, non-bioabsorbable or bioabsorbable materials, further including allograft, autograft, or xenograft materials. 
     FIGS. 1 through 4 illustrate the major components of an exemplary embodiment of the device of the instant invention. FIG. 1 is a side view of the device  100  which generally illustrates the manner in which the various components are related to each other when the device  100  is in use. The device  100  comprises a guide structure  102 , which further comprises a tissue-piercing device  104 , a tissue-piercing device handle  106 , a pair of guide portions  108  and  116 , a guide structure handle  110 , an introducer  112 , and an introducer handle  114 . 
     FIG. 2 better illustrates the tissue-piercing device  104  of FIG.  1 . The tissue-piercing device  104  can be any suitable structure for piercing the soft tissue (not shown) through which a surgeon intends to pass suture or implant material (not shown). The tissue-piercing device  104  can be, for example, a needle or other suitable fine gauged structure. Preferably, the tissue piercing device  104  is formed at the distal end of an elongated cylindrical rod or shaft  118  which preferably can slide in opposite directions within the introducer  112 . The shaft  118  preferably is configured to enable the tissue piercing device  104  to move in one direction within a gap between the guide portions  108  and  116  to pierce soft tissue and to move in an opposite direction for withdrawing the tissue piercing device  104  from the introducer  112 , so that a length of implant material can be inserted into and moved within and through the introducer  112 . Shaft  118  preferably has an outer diameter that is similar to that of the suture or suture-like material which the surgeon intends to pass through the injured or torn tissue. The suture or suture-like material may be of any suitable thickness or diameter but preferably has a diameter ranging from about 0.008 inches to about 0.030 inches. The distal tip  120  of the tissue-piercing device  104  preferably has a relatively sharp point and a generally conical shape that preferably is similar to that of a sewing needle or a pin to facilitate the piercing of the injured soft tissue by the tissue-piercing device  104 . The tissue-piercing device  104  preferably has a handle  106  permanently affixed to its proximal end  122 , thereby enabling the surgeon to control the tissue-piercing device  104  with minimal damage to the surgeon&#39;s surgical glove (not shown). The needle or tissue-piercing device  104  preferably is moveable in opposite directions within the introducer  112  and the guide portions  108  and  116 , such that the needle or tissue-piercing device  104  is moveable in one direction for piercing the segments of torn tissue and in another direction for withdrawing the needle or tissue-piercing device  104  from the segments of torn tissue to enable a length of implant material to be guided through the segments of torn tissue. 
     FIG. 3 better illustrates the introducer  112  of FIG.  1 . In one embodiment, the introducer  112  is preferably an elongated cylindrical tube  124  having an internal diameter that is preferably similar to that of the outer diameter of the tissue-piercing device  104  of FIG.  2 . The introducer tube  112  may have any suitably configured distal end portion, but preferably has a conical or chamfered distal end portion  126  capable of following the tissue-piercing device  104  through soft tissue. In this manner, the introducer tube  112  can pass through injured soft tissue when the introducer tube  112  is placed concentrically over the tissue-piercing device  104  of FIG.  2 . This configuration further permits the introducer tube  112  to extend at least partially into the guide portion  116  of FIG. 4 to form, at least temporarily, a passageway extending substantially between the introducer tube  112  and the guide portion  116  for guiding a length of implant material through the torn tissue. The introducer tube  112  also preferably has an introducer tube handle  114  rigidly attached to its proximal end  128 , which handle  114  preferably has a suitable fastener means, such as threaded member  130 , for attaching the introducer tube handle  114  to a suitable corresponding fastener means, such as a corresponding female threaded portion  132 , shown on guide structure handle  110  in FIG. 4, for attaching the proximal end  134  of the guide structure handle  110  to the introducer tube handle  114 . The introducer tube  112  preferably is configured to receive and guide a length of implant material, and the introducer tube handle  114  preferably comprises a force applying device, such as feeding mechanism  138 . Feeding mechanism  138  is preferably configured to apply a suitable amount of directional force to a length of implant material disposed within the introducer tube  112  to move the length of implant material within and through the introducer tube  112 . Thus, feeding mechanism  138  provides a surgeon with means for advancing a suture or suture-like material from the proximal end of the device  100 , shown in FIG. 1, to the distal end of the device  100  when the tissue-piercing device  104  preferably has been withdrawn from the device  100  after the segments of torn tissue have been suitably pierced. In addition, the feeding mechanism  138  provides the surgeon with suitable means for retracting or reversing the direction of the suture or implant material from the distal end to the proximal end of the guide structure  102  of FIG.  1 . The feeding mechanism  138  is described in greater detail below with reference being had to FIGS. 24,  24 A, and  25 . 
     FIG. 4 better illustrates the assembly of the guide structure  102  of FIG.  1 . Preferably, guide structure  102  is configured to be at least partially located within an articular space, such as a knee joint, to facilitate installation of an implant in soft tissue, such as the meniscus, located within that articular space. Preferably, the guide structure  102  comprises a pair of guide portions  108  and  116 , which are preferably a pair of guide tubes  108  and  116 . Each guide tube  108  and  116  preferably is disposed in a common plane which has a thickness equal to the largest outer diameter of the pair of guide tubes  108  and  116 . Preferably, a gap is formed between the guide tubes  108  and  116 , which gap also is located within this common plane. The introducer tube  112  of FIG.  3  and the tissue-piercing device  104  of FIG. 2 also are moveable within this common plane and preferably are configured to enable a length of implant material to be moved within the common plane. Preferably, the thickness of the common plane is dimensioned to enable the pair of guide tubes  108  and  116  to be at least partially located within an articular space, such as a knee joint (not shown). 
     As further illustrated in FIG. 4, each of the guide tubes  108  and  116  preferably comprises an elongated cylindrical tube having an internal diameter similar to that of the outer diameter of the introducer tube  112  of FIG.  3 . In one embodiment, the guide tube  108  preferably has at least one bend  140  which enables the device  100  of FIG. 1 to be manipulated or maneuvered around anatomical structures, such as bones, and other anatomical features that may hinder or prevent straight or axial passage of the device  100  through the body of a patient. In this embodiment, the introducer tube  112 , shown in FIG. 3, preferably is of suitable flexibility to permit the introducer tube  112  to move lengthwise through the at least one bend in the guide tube  108  and/or through any bends in the guide tube  116 , as required. In one embodiment, guide tube  116  preferably is attached or fixed to the guide tube  108 . The guide tube  116  is preferably an elongated cylindrical tube which preferably is bent in such a manner that its distal end  142  is generally facing the distal end  144  of the guide tube  108 . Preferably, the guide tube  116  also has one or more bends which permit facilitated manipulation or extension of the device around anatomical structures or masses of the body. The guide tube  116  preferably is attached rigidly to the outer diameter of the guide tube  108  so that the proximal end of the guide tube  116  generally faces the same direction as the proximal end of the guide tube  108 . Preferably, the distal ends  142  and  144  of the guide tube  116  and the guide tube  108 , respectively, have openings which are spaced apart and aligned with each other to allow free movement or passage of the tissue-piercing device  104  of FIG. 2, the introducer tube  112  of FIG. 3, and suture or suture-like material through the guide tube  108  and the guide tube  116 . The proximal end  134  of the guide structure  102  preferably is attached rigidly to a guide structure handle  110 . As noted above with respect to FIG. 3, the guide structure handle  110  preferably includes a fastener means, such as a female threaded portion  132 , located on the proximal end  134  of the guide structure handle  110  for matingly and engagingly attaching a suitable corresponding fastener means, such as threaded member  130 , on the introducer tube handle  114 , shown in FIG.  3 . 
     FIGS. 5 through 14 describe the general method of using the device  100  of FIG.  1 . Generally, a method for installing an implant in soft tissue comprises the steps of providing a guide structure, locating the guide structure in a selected orientation with respect to the soft tissue, operating the guide structure to guide a length of implant material through the soft tissue, and withdrawing the guide structure from the soft tissue in a manner which maintains the implant material in the soft tissue and disengages the guide structure from the length of implant material with the legs of the length of implant material in proximity to each other. In a preferred embodiment, the method for installing an implant in soft tissue further comprises the step of manipulating the guide structure into a selected orientation after the length of implant material has been guided through the soft tissue. Preferably, the selected orientation enables the friction between the length of implant material and the soft tissue to cause the guide structure to disengage from the length of implant material as the guide structure is withdrawn from the soft tissue. 
     FIG. 5 illustrates the first step of a preferred method for installing an implant in soft tissue in accordance with the principles of the present invention. It should be understood that while the method of the present invention is exemplified with reference to the repair of a meniscal tear, the principles of the instant invention are applicable to the repair and/or reattachment of a variety of soft tissues and are not intended to be limited to the repair of meniscal tissue. FIG. 5 shows a cross sectional view of the posterior horn of the meniscus  146  placed between the distal end  144  of the guide tube  108  and the distal end  142  of the guide tube  116 . In the illustrated example, the proximal end of the device  100  preferably is inserted concentrically through a portal (not shown) located in a generally anterior aspect of the knee (not shown). The distal end  142  of guide tube  116  is placed on the posterior aspect of the meniscus and is aligned with the tear that is to be repaired, as better seen in FIG.  31 . Preferably, the distal end  144  of guide tube  108  is directed toward the torn segment of the meniscus  148  so that the implant material (not shown) preferably passes directly through the two segments  148  and  146 , respectively, of the meniscus. 
     Referring next to FIG. 6, after the device is placed in the desired location over the meniscus, the tissue-piercing device  104  and the introducer tube  112  preferably are slid concentrically through the guide tube  108  until the distal tip  120  of the tissue-piercing device  104  contacts the torn meniscal tissue  148 . The distal end  126  of the introducer tube  112  preferably trails or follows immediately behind&#39;the conical distal tip  120  of the tissue-piercing device  104  as the tissue-piercing device  104  passes through the soft tissue, thereby reducing potential entrapment of the introducer tube  112  within the meniscal tissue. 
     Turning next to FIG. 7, the tissue-piercing device  104  and introducer tube  112  preferably are then forced through the torn segment of meniscal tissue  148  and the intact meniscal horn tissue  146  until the distal tip  120  of the tissue-piercing device  104  preferably passes the distal end  142  of the guide tube  116  and advances no further. As illustrated in FIG. 8, the introducer tube  112  preferably is advanced until contact is made with the distal end  142  of the guide tube  116 . The tissue-piercing device  104  preferably is then retracted from the device  100  in the direction indicated by the arrow shown in FIG.  7 . 
     Preferably, as illustrated in FIGS. 9 and 10, once the introducer tube  112  and the guide tube  116  are proximate each other at junction or passageway  150 , and the tissue-piercing device  104  has been retracted as shown in FIG. 8, a clear path is established through the passageway  150 , which permits a suitable length of suture, suture-like material, or similar implant material  152  to be fed or passed through the passageway  150  and into the guide tube  116  to deliver an implant or stitch through the torn segments of meniscal tissue  148  and  146 . Preferably, this suture or implant  152  is delivered by the feeding mechanism  138 , as shown in FIG.  1  and described in greater detail below with reference being had to FIGS. 22A,  22 B, and  23 . 
     Once the desired length of suture or implant has been passed through the soft tissue, the introducer tube  112  preferably is retracted toward the body portal in the direction illustrated by the arrow shown in FIG.  11 . Preferably, as illustrated in FIG. 12, the guide structure  102  then is manipulated into a selected orientation, such as being turned  90  degrees for example, within the joint space. As better seen in FIG. 13, this selective manipulation and orientation of the guide structure  102  preferably allow the guide structure  102  to utilize the friction created between the length of implant material  152  and the segments of torn tissue  148  and  146  to disengage the length of implant material  152  from the guide structure  102  as the guide structure  102  is retracted toward the single body portal (not shown) in the direction indicated by the arrow shown in FIG.  13 . As illustrated in FIG. 14, this method of retracting the guide structure  102  ensures that the implant material  152  remains stitched through the two segments of meniscal tissue  148  and  146 , permitting the two legs or end portions  154   a-b  of the suture or implant material  152  to be connected in a manner that facilitates the fusion and healing of the segments of meniscal tissue  148  and  146 . It should be noted that the particular method of connecting the legs or end portions  154   a-b  of implant material  152  is beyond the scope of the present invention. 
     FIGS. 15 and 16 illustrate an exemplary embodiment of the device  200  of the instant invention. The device  200  preferably includes a pair of guide portions comprising a pair of guide tube sets  208  and  216 , each of which further comprises a pair of adjacent guide tubes  209  and  203 , respectively. Preferably, the guide tube sets  208  and  216  are configured to enable portions of a length of implant material to be guided through soft tissue. Preferably, at least one of the pair of guide portions, such as guide tube set  216 , is further configured to maintain the legs of the portions of implant material in adjacent spaced relation to each other as the portions of implant material are guided through the soft tissue. The configuration of the guide tube sets  208  and  218  preferably permit a plurality of tissue-piercing devices and a plurality sutures or implants, or suture or implant legs, to pass through the torn tissue simultaneously. 
     FIG. 16 is a detailed view of the distal end of the device  200  shown in FIG.  15 . This embodiment preferably is used in a different manner than the embodiment illustrated in FIG. 1 in that the suture or implant material is fed from the guide tube set  216  to the guide tube set  208 , rather than from the guide tube  108  to the guide tube  116  as described above with reference to FIGS. 9 and 10. In this embodiment, as seen in cross sectional view  201 , at least one of the pair of guide portions, such as the guide tube set  216 , preferably comprises a single lumen tube structure defining a pair of adjacent guide tube portions  203  having a reduced central portion  205  joining the pair of adjacent guide tube portions  203 . Each of the pair of adjacent guide tube portions  203  is configured to guide a leg or portion of a length of implant material (not shown) in a lengthwise direction, and the central portion  205  is configured to maintain the pair of adjacent guide tube portions  203  in spaced relation to each other, thereby allowing a connecting portion of the length of implant material to slide sideways through the central portion  205  with an interference fit. Thus, preferably a plurality of legs or portions of a length of suture or implant material can be simultaneously fed into the guide tube set  216  and through torn tissue in a spaced apart manner. The cross sectional view  207  of the guide tube set  208  illustrates a preferred double lumen structure having adjacent guide tubes  209  through which legs or portions of implant material can pass subsequent to passing through the guide tubes  216  and the torn soft tissue. 
     FIGS. 17 through 23 illustrate an exemplary method of using the device  200  shown in FIG.  15 . The method of using this embodiment is a modified version of the method described above with reference to FIGS. 5 through 14. As illustrated in FIG. 17, the device preferably is placed over the meniscus with the distal end  242  of the guide tube set  216  contacting the posterior aspect of the meniscus  246  and the distal ends  244  of the guide tube set  208  generally directed toward the torn piece of meniscal tissue  248 . As better seen in FIG. 18, the tissue-piercing devices  204  preferably perform a similar function and are used in an identical manner to that described above with reference to FIGS. 5 through 14. 
     FIG. 19 illustrates a plurality of introducer tubes  212  concentrically inserted within the guide tube set  208  and fully extended toward the distal end  242  of guide tube set  216 . The method of passing the introducer tubes  212  through the segments of torn tissue is as described above with reference to FIGS. 6 through 8, notwithstanding the difference of using a plurality of introducer tubes  212  and a plurality of tissue-piercing devices  204 , as shown in FIG.  18 . In a manner similar to that described above with reference to FIGS. 8 through 10, the method of using the embodiment of FIG. 15 preferably places the introducer tubes  212  and the guide tube set  216  proximate each other at a junction or passageway  250 . Thus, after the tissue-piercing devices preferably have been retracted in a manner similar to that described above with reference to FIG. 8, a clear path is established through the passageway  250 , which permits a plurality of legs or portions of a suitable length of suture, suture-like material, or similar implant material to be fed or passed through the guide tube set  216 , through the passageway  250 , and then into the introducer tubes  212 , effectively delivering a suture or stitch through torn segments of meniscal tissue. 
     FIG. 20 illustrates a suture or implant  252 , having a connecting portion  211  and legs or end portions  254   a-b , being advanced, as indicated by the arrows, through the guide tube set  216 , through the segments of meniscal tissue  246  and  248 , and into the introducer tubes  212  within the guide tube set  208 . Preferably, as the suture or implant  252  continues to be advanced by a surgeon pulling on the end portions  254   a-b , the loop or connecting portion  211  eventually contacts the proximal ends  213  of the guide tube set  216  and has an interference fit within the guide tube set  216 . As illustrated in FIG. 21, as the suture or implant  252  is advanced further, the loop  211  eventually clears the distal end  242  of the guide tube set  216  and contacts the posterior aspect of the meniscal horn tissue  248 . Then, as seen in FIG. 22, the guide structure  202  preferably is selectively oriented, or turned, and retracted toward the body portal, as described above in greater detail with reference to FIGS. 12 through 14. In this manner, a complete stitch of the implant material  252  is delivered through the two segments of torn meniscal tissue with a loop  211  on the posterior aspect of the meniscus  248 . As illustrated in FIG. 23, the plurality of legs or end portions  254   a-b  of implant material  252  are then positioned so that they easily may be connected to facilitate the fusion and healing of the segments of meniscal tissue  248  and  246 . 
     FIGS. 24 and 24A are detailed views of an exemplary embodiment of the inventive suture or implant feeding mechanism  138 , as shown in FIG.  1 . The feeding mechanism is a force applying device, which preferably includes a drive wheel  131  extending at least partially into the handle  114  and the introducer tube  112 . Preferably, the drive wheel  131  is rotatable about an axis or axle  137  and has an external surface suitably configured for applying force to and moving a length of implant material  252  through the introducer tube  112  of FIG.  1 . The drive wheel  131  preferably has an outer diameter  133  and an inner diameter  135 , wherein the inner diameter  135  is larger than the outer diameter of the axle  137 . The suture guide  139  within the introducer tube handle  114  has a proximal suture introducing end  141  and a distal suture receiving end  143 . In accordance with one embodiment of the invention, the axle  137  and the drive wheel  131  are both selectively moveable in one direction transverse to the length of implant material  252  within the introducer tube  112  to engage and move or drive the length of implant material and are moveable in an opposite direction to disengage from the length of implant material to allow the length of implant material to slide within the introducer tube  112 . In another embodiment, the drive wheel  131  is selectively moveable relative to the axle  137  in one direction transverse tot eh length of implant material  252  within the introducer tube  112  to engage and move or drive the length of implant material and is moveable in an opposite direction to disengage from the length of implant material to allow the length of implant material to slide within the introducer tube  112 . In both of these embodiments, a surgeon is thereby permitted to depress and rotate the drive wheel  131  to move the length of implant material  252  through the introducer tube  112  by frictionally engaging the implant material  252  with the drive wheel  131 . In this manner, a surgeon also can selectively utilize implant materials  252  of varying thickness or diameters with a single device, rather than requiring a particular device for each of the desired suture or implant diameters, since the feeding mechanism  138  preferably permits selective depression of the drive wheel  131 , as required by the diameter or thickness of the employed implant material  252 . As illustrated in the top view of FIG. 24A, the outer surface  133  of the drive wheel  131  preferably has a suitably configured surface, such as teeth or serrations  145 , for effectively gripping and moving the suture or implant material through the device. 
     FIG. 25 illustrates an alternative embodiment of the suture or implant feeding mechanism of the instant invention. In this configuration, the feeding mechanism or force applying device preferably includes a second drive wheel  247  rotatable about an axis  249  parallel to the axis  237  of a first drive wheel  231 . The second drive wheel  247  preferably has an outer surface that engages the first drive wheel  231  in a manner that rotates the first drive wheel  231  in a direction opposite that of the second drive wheel  247 . Thus, when a surgeon depresses and rotates second drive wheel  247 , a rotational frictional force is applied through second drive wheel  247  to first drive wheel  231 , which ultimately results in movement of the implant material  252  through the guide structure in the same direction that the surgeon rotates the second drive wheel  247 . The addition of the second drive wheel  247  to the feeding mechanism  238  enables the suture or implant material  252  to advance, reversibly, in the same direction that the second drive wheel  247  is rotated. Preferably, each drive wheel  231  and  247  has a suitably configured surface, such as teeth or serrations, on its outer diameter to engage the drive wheels. In this manner, the drive wheels  231  and  247  preferably act as gears to grip and move the suture or implant material  252  through the guide structure. The drive wheels  231  and  247  have outer diameters  251  and  253 , respectively, and axles  237  and  249 , respectively, which preferably are rigidly attached to a pair of directly opposed slots  255  on the introducer handle  214 . The slots  255  enable the drive wheels  231  and  247  to rotate and to move in a downward or transverse direction to conform selectively to varying suture diameters and thicknesses, as more fully described above with reference to FIGS. 24 and 24A. 
     As noted above with reference to FIG. 4, a plurality of angular configurations or bends in the guide structure and/or the guide tube(s) of the instant invention may be required to allow the instrument to conform to particular anatomical features or structures of the human body. FIGS. 26 and 26A illustrate exemplary embodiments of the device of the instant invention which include these types of bends in the guide structure. Although various embodiments of the present invention as described herein position the distal end of the guide structure in a generally horizontal manner, this configuration is not necessarily desirable in all cases. Depending upon such factors as the particular anatomical structures surrounding the site of the surgical procedure or the location of the body portal through which the procedure is conducted, the guide structure may preferably be oriented in an upward, downward, leftward, or rightward direction, as these directional orientations are generally illustrated and defined in FIG.  26 B. FIG. 26 illustrates an exemplary angular bend in the guide structure  302  that allows the distal end  303  of the device to be directed generally leftward with an angle  304  when the guide structure  302  is maintained in a generally horizontally position. FIG. 26A illustrates another exemplary angular bend in the guide structure  402  that allows the distal end  403  of the device to be directed generally upward with an angle  404  when the guide structure  402  is maintained in a generally horizontally position. It should be understood that a variety of angular configurations of the inventive guide structure are possible and all such configurations are intended to come within the spirit and scope of the present invention. The present invention is not intended to be limited to the exemplary angular configurations illustrated and described herein. 
     FIGS. 27 and 27A illustrate a top and a side view, respectively, of another exemplary embodiment of the present invention, wherein the guide structure  502  preferably includes a guide tube  508  configured to guide a length of implant material through segments of torn soft tissue and a receiver  501  connected to the guide tube. Preferably, the guide structure further comprises a support device  503  connected with the receiver  501 , and, preferably, receiver  501  further comprises a receiving portion  505  configured to receive a length of implant material guided through segments of torn soft tissue. The receiving portion  505  preferably includes a plurality of elements  505   a-b  configured to form an opening for receiving and retaining a length of suture or implant material guided through segments of torn tissue. In the illustrated example, elements  505   a-b  are selectively moveable relative to each other to form an opening  507  and are controlled by a manipulator  511  on the support device  503 . Preferably, the manipulator  511  is coupled to a hand-operated mechanism, such as a trigger, which is preferably located on the handle or proximal end (not shown) of the guide structure so that a surgeon may control the elements  505   a-b  at a distance from the surgical site. 
     As illustrated in FIGS. 27B and 27C, the plurality of elements  505   a-b  preferably are used to grasp a suture or suture-like material  552  or a needle or other tissue-piercing device  504  that is suitably affixed or swedged to an implant or suture  552 . In this embodiment, if a needle or other tissue-piercing device  504  is suitably affixed or swedged to an implant  552 , the tissue-piercing device  504  is suitably configured and/or dimensioned such that the entire length of tissue-piercing device  504  passes through the soft tissue and is grasped and retained by the receiver  501 . As the elements  505   a-b  are selectively manipulated by the manipulator  511 , the elements  505   a-b  preferably are positioned such that when the suture material or implant  552  or the tissue-piercing device  504  affixed to a suture or implant  152  passes through the distal end  544  of the guide tube  508 , the implant  552  or tissue-piercing device  504  affixed to an implant  552  directly contacts the plurality of elements  505   a-b,  thereby preventing damage to soft tissue behind the plurality of elements  505   a-b . When the plurality of elements  505   a-b  are separated by the manipulator  511 , the opening  507  is sufficient for the implant  552  and/or the tissue-piercing device  504  affixed to an implant  552  to pass between the plurality of elements  505   a-b  and into the opening  507 . The plurality of elements  505   a-b  are suitably shaped to grasp the implant  552  and/or the tissue-piercing device  504  affixed to an implant  552 . Thus, as the plurality of elements  505   a-b  are opened or separated by the manipulator  511 , the implant  552  or the tissue-piercing device  504  affixed to an implant  552  is advanced through the guide tube  508  to the plurality of elements  505   a-b  until sufficient implant material  552  has passed between the plurality of elements  505   a-b  to allow the plurality of elements  505   a-b  to grasp and retain the tissue-piercing device  504  or implant material  552 . Finally, the guide structure  502  can be selectively oriented and retracted from the surgical site and/or the body portal, as described above with reference to FIGS. 12 through 14, leaving a suitable length of the implant material  552  within the segments of torn soft tissue. 
     In the embodiment illustrated in FIG. 27B, and as noted above, the needle  504  is permanently attached or swedged to the suture or implant material  552 . A rigid member (not shown) advances the needle  504  through guide tube  508  and into the injured tissue. A modified introducer tube  512  can be placed concentrically over the implant material  552  to remotely transfer an axial force from the surgeon to push the needle  504  and the implant material  552  through the soft tissue and into the pair of elements  505   a-b . Unlike the introducer tube  112  of FIG. 1, the introducer tube  512  preferably is modified such that the distal end  526  is blunt and does not have a chamfer. 
     In another embodiment, as illustrated in FIG. 27D, the guide structure  502  preferably comprises a support device  503  which further includes a support member  509  connected to a shield  511 . The shield  511  preferably is configured to prevent the tissue-piercing device  504  from piercing other tissue after the tissue-piercing device  504  has pierced the segments of torn soft tissue and guided the implant material  552  into the receiver  501 . 
     FIGS. 28 and 28A illustrate another exemplary embodiment of the present invention. This embodiment is similar to that of FIGS. 27-27C. However, whereas the receiving portion  505  of FIGS. 27-27C includes a selectively manipulable plurality of elements  505   a-b , the receiving portion  605 , as illustrated in FIGS. 28-28A, preferably includes a plurality of elements  605   a-b  which are flexible and are biased toward an orientation in which the elements  605   a  and  605   b  form an opening or space  607 . The flexibility of the plurality of elements  605   a-b  enables the elements  605   a  and  605   b  to be spread apart or separated as a length of implant material  652  is guided through the opening  607 . Further, the bias of the elements  605   a  and  605   b  enables the elements  605   a  and  605   b  to return to their original, closed orientation after the tissue-piercing device  604  affixed to an implant  652  has passed into the opening  609 , thereby grasping and retaining the tissue-piercing device  604  affixed to an implant  652  within the opening  607 . The receiver  601  preferably is configured as a fork having two elements or tines  605   a  and  605   b  that preferably move apart slightly when the tissue-piercing device  604  forcibly passes between them using introducer tube  612 . In this embodiment, introducer tube  612  preferably is modified such that the distal end of the introducer tube  612  preferably is blunt, rather than conical or chamfered as described above. The elements  605   a  and  605   b  are suitably configured to grasp or grip the tissue-piercing device  604 . Preferably, a space or opening  607  is formed between the elements  605   a-b , which is of suitable length, width, and shape to facilitate grasping and retaining the tissue-piercing device  604  within the space or opening  607 . Preferably, once the tissue-piercing device  604  has been suitably grasped and retained within the space or opening  607 , the guide structure  602  is selectively oriented and retracted as described more fully above. 
     In another embodiment, as illustrated in FIG. 28B, the tissue-piercing device  604  preferably is fixed or swedged to the length of implant material. In this embodiment, the guide structure  602  preferably comprises support device  603  which further includes a support member  609  connected to a shield  611 . The shield  611  preferably is configured to prevent the tissue-piercing device  604  from piercing other body tissue after the tissue-piercing device  604  has pierced the segments of torn soft tissue and guided the implant material  652  into the receiver  601 . 
     Depending upon the nature or location of the port of entry into the body or the structure of the soft tissue to be repaired, it may be necessary to deliver the suture or implant material in a particular orientation, such as a vertical, horizontal, or diagonal orientation, with respect to the instrument. Various embodiments of the present invention as described herein provide a method for repairing soft tissue by delivering a vertical stitch through that tissue. Various other embodiments of the invention provide for delivering and implanting only one leg of the suture or implant material within the soft tissue, as exemplified in FIG.  13 . Alternative embodiments of the present invention, as described hereinafter with reference to FIGS. 29,  30 , and  30 A, provide a method for selectively orienting and implanting a plurality of legs or portions of the suture or implant material within soft tissue. 
     FIG. 29 represents an exemplary embodiment of the present invention which is capable of delivering a vertically oriented stitch or length of implant material within the soft tissue. In this embodiment, the guide structure  702  preferably includes a guide tube  708 , a receiver tube  716  adjacent the guide tube  708 , and a channel device  701  connected to a support member  703 . Preferably, the guide tube  708  and receiver tube  716  are suitably spaced apart from the channel device  701  so that soft tissue in which an implant is being inserted can be disposed between the channel device  701  and the adjacent guide tube  708  and receiver tube  716 . The channel device  701  is suitably configured to receive a length of implant material (not shown) extending through the guide tube  708  and through segments of torn tissue and is further configured to guide the length of implant material back through the soft tissue and toward the receiver tube  716 . The guide tube  708  and receiver tube  716  are each suitably configured to allow a tissue-piercing device (not shown) and an introducer tube (not shown) to be delivered through the soft tissue to the distal ends  705   a-b  of the channel device  701 . As shown, the tubes  708  and  716 , respectively, preferably are oriented in a sagittal fashion. Preferably, as described above with reference to the embodiment of FIG. 1, the needles or tissue-piercing devices are retracted, and the introducer tubes remain connected to the distal ends  705   a-b  of the channel device  701 . Thus, a path or passageway is created through which a suture or suture-like material preferably is guided and passed from guide tube  708 , through the segments of tissue  748  and  746 , through the channel device  701 , and then into receiver tube  716 . After the suture or implant material is suitably guided through the soft tissue and then into the receiver tube  716 , the guide structure  702  preferably is selectively oriented and retracted, as described above, installing or delivering a vertical stitch in the soft tissue with both legs of the implant material contained within that tissue. 
     In another embodiment, as better seen in FIGS. 30 and 30A, the guide structure  802  preferably is suitably configured to orient the channel device  801  and the tubes  808  and  816  in a manner which delivers a horizontal stitch through the soft tissue. FIG. 30A illustrates the guide structure  802  and the meniscus from a superior vantage point. In this embodiment, the guide tubes  808  and  816  preferably are oriented in a transverse fashion. The channel device  801  preferably also is oriented in a transverse fashion. When the introducer tubes (not shown) contact the channel device  801 , a path or passageway is created through which a suture or suture-like material preferably is passed from one guide tube  808  to the channel device  801  and then to another guide tube  816 . Preferably, the guide structure  802  then is selectively oriented and retracted, and a horizontal stitch is installed in the soft tissue with both legs of the implant material contained within that tissue. 
     FIG. 32 is a diagrammatic depiction of a lateral view of the knee which illustrates an exemplary method of using the embodiment of the present device shown in FIG. 1 to repair the meniscus. It should be understood that this diagram is illustrative only and merely demonstrates one method of using one embodiment of the present invention. It should be noted further that FIG. 32 is not drawn to scale. In the illustrated example, a longitudinal tear in the meniscus, which is the cartilaginous tissue located between the femur and the tibia, of a left knee is being repaired. Arthroscopic repair of the meniscus requires no less than two incisions made in the anterior aspect of the knee. One of these required incisions, often referred to as the “working portal”, is employed to insert various surgical instruments into the joint to perform the procedure. The other required incision, frequently referred to as the “scope portal”, is used to insert the arthroscope. A third incision may be made, at the surgeon&#39;s discretion, to enable the delivery of fluid into the joint to distend and thereby enlarge the articular space in which the procedure is performed. As depicted in FIG. 32, the inventive device of FIG. 1 is inserted through the working portal and placed in the joint space with the distal, hook-shaped end placed over the posterior horn of the meniscus. In this case, the device is used to install a vertical stitch in the meniscus with an implant passing from one guide tube  116 , through the meniscal tissue, and then into a second guide tube  108 . The arthroscope inserted into the scope portal is used to view this repair and to project images of the surgical site onto a monitor located within the surgeon&#39;s view. After the device passes a stitch through the meniscal tissue, the device is selectively oriented, preferably by rotating the device 90 degrees, and then retracted from the surgical site so that the suture or implant legs may be joined by the surgeon through the working portal to facilitate fusion and healing of the meniscus. In accordance with the invention, selective orientation of the device is designed to enable friction between the implant and the meniscus to hold the implant in place and to enable the implant to disengage from the device as the device is withdrawn from the meniscus and toward the portal. Thus, as the device disengages from the surgical site, the legs of the implant pass through the gap between the guide tubes and are located in proximity with each other. However, it should be understood that while rotating the device 90 degrees is particularly well suited to the repair of meniscal tissue, the device of the present invention can be selectively oriented in any suitable manner, depending upon the location of the surgical site and the particular tissue that is being repaired or reattached. 
     As those skilled in the art will appreciate, based upon the above description, the principles of the present invention are equally applicable to the delivery of a diagonal stitch through the segments of torn tissue. The guide tube, receiver tube, and channel device can be suitably configured and oriented in a diagonal manner, and a diagonal stitch therefore can be delivered and installed through the soft tissue with both legs of the implant material contained within that tissue. 
     The device of the instant invention can be either reusable or disposable. The components of the present invention, such as the tissue-piercing device(s), guide tube(s), introducer tube(s), and receiver tube(s), are preferably made of stainless steel, though in some cases titanium or Nitonol will serve better where multiple or severe angles or bends are required in the guide structure. The handles and the implant drive wheels can be made of either metal or medical grade plastics. In some cases, where the force required to drive the guide structure through tissue is sufficiently low, the guide tube(s), introducer tube(s), and receiver tube(s) can be made of medical grade plastic to allow for greater flexibility. 
     While the invention has been particularly shown and described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and the scope of the present invention.