Abstract:
A suture passer comprising:
       a shaft having an axis;   a first jaw mounted to the shaft in alignment with the axis, the first jaw being configured to releasably support a length of suture thereon;   a second jaw movably mounted to the shaft; and   a needle movably mounted to the shaft, the needle having a hook and being configured to reciprocate in alignment with the axis so that the hook can selectively pass by the second jaw and engage suture releasably supported on the first jaw;   wherein the first jaw comprises a spring for selectively binding the suture to the first jaw.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS 
       [0001]    This patent application claims benefit of: 
         [0002]    (i) pending prior U.S. Provisional Patent Application Ser. No. 61/270,985, filed Jul. 15, 2009 by Scott Heneveld et al. for METHOD AND APPARATUS FOR ACCESSING THE INTERIOR OF A HIP JOINT, INCLUDING THE PROVISION AND USE OF A NOVEL DOUBLE SUTURE PASSER (Attorney&#39;s Docket No. FIAN-45 PROV); and 
         [0003]    (ii) pending prior U.S. Provisional Patent Application Ser. No. 61/327,431, filed Apr. 23, 2010 by David Skinlo et al. for METHOD AND APPARATUS FOR ACCESSING THE INTERIOR OF A HIP JOINT, INCLUDING THE PROVISION AND USE OF A NOVEL SUTURE PASSER (Attorney&#39;s Docket No. FIAN-56 PROV). 
         [0004]    The two (2) above-identified patent applications are hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0005]    This invention relates to surgical methods and apparatus in general, and more particularly to surgical methods and apparatus for treating a hip joint. 
       BACKGROUND OF THE INVENTION 
     The Hip Joint in General 
       [0006]    The hip joint is a ball-and-socket joint which movably connects the leg to the torso. The hip joint is capable of a wide range of different motions, e.g., flexion and extension, abduction and adduction, medial and lateral rotation, etc. See  FIGS. 1A ,  1 B,  1 C and  1 D. 
         [0007]    With the possible exception of the shoulder joint, the hip joint is perhaps the most mobile joint in the body. Significantly, and unlike the shoulder joint, the hip joint carries substantial weight loads during most of the day, in both static (e.g., standing and sitting) and dynamic (e.g., walking and running) conditions. 
         [0008]    The hip joint is susceptible to a number of different pathologies. These pathologies can have both congenital and injury-related origins. In some cases, the pathology can be substantial at the outset. In other cases, the pathology may be minor at the outset but, if left untreated, may worsen over time. More particularly, in many cases, an existing pathology may be exacerbated by the dynamic nature of the hip joint and the substantial weight loads imposed on the hip joint. 
         [0009]    The pathology may, either initially or thereafter, significantly interfere with patient comfort and lifestyle. In some cases, the pathology can be so severe as to require partial or total hip replacement. A number of procedures have been developed for treating hip pathologies short of partial or total hip replacement, but these procedures are generally limited in scope due to the significant difficulties associated with treating the hip joint. 
         [0010]    A better understanding of various hip joint pathologies, and also the current limitations associated with their treatment, can be gained from a more thorough understanding of the anatomy of the hip joint. 
       Anatomy of the Hip Joint 
       [0011]    The hip joint is formed at the junction of the leg and the torso. More particularly, and looking now at  FIG. 2 , the head of the femur is received in the acetabular cup of the hip, with a plurality of ligaments and other soft tissue serving to hold the bones in articulating condition. 
         [0012]    More particularly, and looking now at  FIG. 3 , the femur is generally characterized by an elongated body terminating, at its top end, in an angled neck which supports a hemispherical head (also sometimes referred to as “the ball”). As seen in  FIGS. 3 and 4 , a large projection known as the greater trochanter protrudes laterally and posteriorly from the elongated body adjacent to the neck of the femur. A second, somewhat smaller projection known as the lesser trochanter protrudes medially and posteriorly from the elongated body adjacent to the neck. An intertrochanteric crest ( FIGS. 3 and 4 ) extends along the periphery of the femur, between the greater trochanter and the lesser trochanter. 
         [0013]    Looking next at  FIG. 5 , the hip socket is made up of three constituent bones: the ilium, the ischium and the pubis. These three bones cooperate with one another (they typically ossify into a single “hip bone” structure by the age of 25 or so) in order to collectively form the acetabular cup. The acetabular cup receives the head of the femur. 
         [0014]    Both the head of the femur and the acetabular cup are covered with a layer of articular cartilage which protects the underlying bone and facilitates motion. See  FIG. 6 . 
         [0015]    Various ligaments and soft tissue serve to hold the ball of the femur in place within the acetabular cup. More particularly, and looking now at  FIGS. 7 and 8 , the ligamentum teres extends between the ball of the femur and the base of the acetabular cup. As seen in  FIGS. 8 and 9 , a labrum is disposed about the perimeter of the acetabular cup. The labrum serves to increase the depth of the acetabular cup and effectively establishes a suction seal between the ball of the femur and the rim of the acetabular cup, thereby helping to hold the head of the femur in the acetabular cup. In addition to the foregoing, and looking now at  FIG. 10 , a fibrous capsule extends between the neck of the femur and the rim of the acetabular cup, effectively sealing off the ball-and-socket members of the hip joint from the remainder of the body. The foregoing structures (i.e., the ligamentum teres, the labrum and the fibrous capsule) are encompassed and reinforced by a set of three main ligaments (i.e., the iliofemoral ligament, the ischiofemoral ligament and the pubofemoral ligament) which extend between the femur and the perimeter of the hip socket. See, for example,  FIGS. 11 and 12 , which show the iliofemoral ligament, with  FIG. 11  being an anterior view and  FIG. 12  being a posterior view. 
       Pathologies of the Hip Joint 
       [0016]    As noted above, the hip joint is susceptible to a number of different pathologies. These pathologies can have both congenital and injury-related origins. 
         [0017]    By way of example but not limitation, one important type of congenital pathology of the hip joint involves impingement between the neck of the femur and the rim of the acetabular cup. In some cases, and looking now at  FIG. 13 , this impingement can occur due to irregularities in the geometry of the femur. This type of impingement is sometimes referred to as cam-type femoroacetabular impingement (i.e., cam-type FAI). In other cases, and looking now at  FIG. 14 , the impingement can occur due to irregularities in the geometry of the acetabular cup. This latter type of impingement is sometimes referred to as pincer-type femoroacetabular impingement (i.e., pincer-type FAI). Impingement can result in a reduced range of motion, substantial pain and, in some cases, significant deterioration of the hip joint. 
         [0018]    By way of further example but not limitation, another important type of congenital pathology of the hip joint involves defects in the articular surface of the ball and/or the articular surface of the acetabular cup. Defects of this type sometimes start out fairly small but often increase in size over time, generally due to the dynamic nature of the hip joint and also due to the weight-bearing nature of the hip joint. Articular defects can result in substantial pain, induce and/or exacerbate arthritic conditions and, in some cases, cause significant deterioration of the hip joint. 
         [0019]    By way of further example but not limitation, one important type of injury-related pathology of the hip joint involves trauma to the labrum. More particularly, in many cases, an accident or sport-related injury can result in the labrum being torn away from the rim of the acetabular cup, typically with a tear running through the body of the labrum. See  FIG. 15 . These types of injuries can be very painful for the patient and, if left untreated, can lead to substantial deterioration of the hip joint. 
       The General Trend Toward Treating Joint Pathologies Using Minimally-Invasive, and Earlier, Interventions 
       [0020]    The current trend in orthopedic surgery is to treat joint pathologies using minimally-invasive techniques. Such minimally-invasive, “keyhole” surgeries generally offer numerous advantages over traditional, “open” surgeries, including reduced trauma to tissue, less pain for the patient, faster recuperation times, etc. 
         [0021]    By way of example but not limitation, it is common to re-attach ligament in the shoulder joint using minimally-invasive, “keyhole” techniques which do not require large incisions into the interior of the shoulder joint. By way of further example but not limitation, it is common to repair torn meniscal cartilage in the knee joint, and/or to replace ruptured ACL ligaments in the knee joint, using minimally-invasive techniques. 
         [0022]    While such minimally-invasive approaches can require additional training on the part of the surgeon, such procedures generally offer substantial advantages for the patient and have now become the standard of care for many shoulder joint and knee joint pathologies. 
         [0023]    In addition to the foregoing, in view of the inherent advantages and widespread availability of minimally-invasive approaches for treating pathologies of the shoulder joint and knee joint, the current trend is to provide such treatment much earlier in the lifecycle of the pathology, so as to address patient pain as soon as possible and so as to minimize any exacerbation of the pathology itself. This is in marked contrast to traditional surgical practices, which have generally dictated postponing surgical procedures as long as possible so as to spare the patient from the substantial trauma generally associated with invasive surgery. 
       Treatment for Pathologies of the Hip Joint 
       [0024]    Unfortunately, minimally-invasive treatments for pathologies of the hip joint have lagged far behind minimally-invasive treatments for pathologies of the shoulder joint and the knee joint. This is generally due to (i) the constrained geometry of the hip joint itself, and (ii) the nature and location of the pathologies which must typically be addressed in the hip joint. 
         [0025]    More particularly, the hip joint is generally considered to be a “tight” joint, in the sense that there is relatively little room to maneuver within the confines of the joint itself. This is in marked contrast to the shoulder joint and the knee joint, which are generally considered to be relatively “spacious” joints (at least when compared to the hip joint). As a result, it is relatively difficult for surgeons to perform minimally-invasive procedures on the hip joint. 
         [0026]    Furthermore, the pathways for entering the interior of the hip joint (i.e., the natural pathways which exist between adjacent bones and/or delicate neurovascular structures) are generally much more constraining for the hip joint than for the shoulder joint or the knee joint. This limited access further complicates effectively performing minimally-invasive procedures on the hip joint. 
         [0027]    In addition to the foregoing, the nature and location of the pathologies of the hip joint also complicate performing minimally-invasive procedures on the hip joint. By way of example but not limitation, consider a typical detachment of the labrum in the hip joint. In this situation, instruments must generally be introduced into the joint space using an angle of approach which is offset from the angle at which the instrument addresses the tissue. This makes drilling into bone, for example, significantly more complicated than where the angle of approach is effectively aligned with the angle at which the instrument addresses the tissue, such as is frequently the case in the shoulder joint. Furthermore, the working space within the hip joint is typically extremely limited, further complicating repairs where the angle of approach is not aligned with the angle at which the instrument addresses the tissue. 
         [0028]    As a result of the foregoing, minimally-invasive hip joint procedures are still relatively difficult to perform and relatively uncommon in practice. Consequently, patients are typically forced to manage their hip pain for as long as possible, until a resurfacing procedure or a partial or total hip replacement procedure can no longer be avoided. These procedures are generally then performed as a highly-invasive, open procedure, with all of the disadvantages associated with highly-invasive, open procedures. 
         [0029]    As a result, there is, in general, a pressing need for improved methods and apparatus for treating pathologies of the hip joint. 
       The Fibrous Capsule 
       [0030]    As noted above, a fibrous capsule extends between the neck of the femur and the rim of the acetabular cup, effectively sealing off the ball-and-socket elements of the hip joint from the remainder of the body. 
         [0031]    While the fibrous capsule provides an important function in encapsulating the hip joint, it also presents a significant obstacle to arthroscopically treating pathologies of the hip joint. More particularly, the fibrous capsule presents a tough physical barrier which must be penetrated in order to arthroscopically access the interior of the hip joint. However, the penetration of this tough physical barrier must be effected very carefully, since the anatomical structures which are located immediately below the fibrous capsule are frequently delicate and sensitive to damage. 
         [0032]    In addition to the foregoing, the fibrous capsule generally sits in close proximity to the underlying bone. As a result, the workspace located between the fibrous capsule and the underlying bone is typically quite limited, thereby presenting significant visualization and operational challenges to the surgeon. 
         [0033]    By way of example but not limitation, arthroscopic treatment of cam-type femoroacetabular impingement (i.e., cam-type FAI) is significantly complicated by the limited workspace present within the fibrous capsule. More particularly, cam-type FAI is generally caused by irregular overgrowths in the geometry of the femur. Treatment of cam-type FAI generally calls for debridement of these femoral overgrowths using a burr or other debridement tool. However, the lack of workspace between the overlying fibrous capsule and the underlying femur can make such debridement procedures technically challenging for even the most experienced surgeons, because it can severely limit the field of vision within the workspace and inhibit proper positioning of the burr. 
         [0034]    As a result, there is a pressing need for an improved method and apparatus for increasing the workspace around the femur during an arthroscopic hip procedure. 
       Capsule Release and Subsequent Re-Stitching 
       [0035]    It has been recognized that the workspace around the top end of the femur can be significantly increased during an arthroscopic procedure if the fibrous capsule can be laid open at the start of the arthroscopic procedure and then, at the conclusion of the procedure, the fibrous capsule restored, e.g., by suturing. 
         [0036]    More particularly, it has been recognized that an arthroscopic procedure can be performed on the hip joint by (i) creating one or more access portals from the surface of the skin down to the fibrous capsule; (ii) opening the fibrous capsule so as to expose the underlying joint; (iii) performing the desired therapeutic procedure on the underlying joint (e.g., debridement of a femoral overgrowth so as to treat a cam-type FAI); and (iv) restoring the fibrous capsule at the conclusion of the procedure by suturing closed the laid-open capsule. 
         [0037]    However, heretofore, it has been technically challenging to arthroscopically suture closed the laid-open fibrous capsule at the conclusion of the therapeutic procedure. This is largely because (i) the workspace present at the remote surgical site is quite limited, and (ii) the fibrous capsule is made up of unusually tough tissue, which can make it extremely difficult to arthroscopically pass suture through the fibrous capsule in the suturing operation. 
         [0038]    Thus there is a need for a new method and apparatus for passing suture through the fibrous capsule in a suturing operation, thereby making it more practical for a surgeon to arthroscopically operate on the hip joint by first laying open the fibrous capsule, performing the desired procedure on the hip joint, and then closing the fibrous capsule by suturing at the conclusion of the procedure. 
       SUMMARY OF THE INVENTION 
       [0039]    The present invention provides a novel method and apparatus for passing suture through the fibrous capsule in a suturing operation, thereby making it more practical for a surgeon to arthroscopically operate on the hip joint by first laying open the fibrous capsule, performing the desired procedure on the hip joint, and then closing the fibrous capsule by suturing at the conclusion of the procedure. 
         [0040]    In one form of the invention, there is provided a suture passer comprising:
       a shaft having an axis;   a distal jaw mounted to the shaft in alignment with the axis, the distal jaw being configured to releasably support a length of suture thereon;   a proximal jaw movably mounted to the shaft, the proximal jaw being configured to reciprocate in alignment with the axis so as to advance toward, and retract from, the distal jaw;   an inner needle movably mounted to the shaft, the inner needle having a hook and being configured to reciprocate in alignment with the axis so that the hook can selectively pass by the proximal jaw and engage the suture releasably supported on the distal jaw; and   an outer needle movably mounted to the shaft in coaxial disposition with the inner needle.       
 
         [0046]    In another form of the invention, there is provided a suture passer comprising:
       a shaft having an axis;   a first jaw mounted to the shaft in alignment with the axis, the first jaw being configured to releasably support a length of suture thereon;   a second jaw movably mounted to the shaft; and   a needle movably mounted to the shaft, the needle having a hook and being configured to reciprocate in alignment with the axis so that the hook can selectively pass by the second jaw and engage suture releasably supported on the first jaw;   wherein the first jaw comprises a spring for selectively binding the suture to the first jaw.       
 
         [0052]    In another form of the invention, there is provided a needle assembly for use in a suture passer, the needle assembly comprising an inner needle having a hook thereon, and an outer needle concentrically disposed about the inner needle, the inner needle being spring mounted to the outer needle. 
         [0053]    In another form of the invention, there is provided a method for passing suture through tissue, the method comprising:
       releasably supporting a length of suture on a distal jaw;   longitudinally advancing a proximal jaw toward the distal jaw so as to releasably clamp tissue therebetween;   advancing an inner needle supported by an outer needle through the tissue so that a hook on the inner needle engages the suture releasably supported on the distal jaw; and   retracting the inner needle and outer needle back through the tissue, with the inner needle carrying the suture therewith.       
 
         [0058]    In another form of the invention, there is provided a method for passing suture through tissue, the method comprising:
       releasably supporting a length of suture on a first jaw by binding the suture to the first jaw with a spring;   advancing a second jaw toward the first jaw so as to releasably clamp tissue therebetween;   advancing a needle through the tissue so that a hook on the needle engages the suture releasably supported on the first jaw; and   retracting the needle back through the tissue, with the needle carrying the suture therewith.       
 
         [0063]    In another form of the invention, there is provided a method for treating a hip joint, the method comprising:
       providing a suture passer, the suture passer comprising:
           a shaft having an axis;   a distal jaw mounted to the shaft in alignment with the axis, the distal jaw being configured to releasably support a length of suture thereon;   a proximal jaw movably mounted to the shaft, the proximal jaw being configured to reciprocate in alignment with the axis so as to advance toward, and retract from, the distal jaw;   an inner needle movably mounted to the shaft, the inner needle having a hook and being configured to reciprocate in alignment with the axis so that the hook can selectively pass by the proximal jaw and engage the suture releasably supported on the distal jaw; and   an outer needle movably mounted to the shaft in coaxial disposition with the inner needle;   
           laying open the fibrous capsule of the hip joint;   performing a procedure on the hip joint; and   closing the fibrous capsule by suturing the fibrous capsule with the suture passer.       
 
         [0073]    In another form of the invention, there is provided a method for treating a hip joint, the method comprising:
       providing a suture passer, the suture passer comprising:
           a shaft having an axis;   a first jaw mounted to the shaft in alignment with the axis, the first jaw being configured to releasably support a length of suture thereon;   a second jaw movably mounted to the shaft; and   a needle movably mounted to the shaft, the needle having a hook and being configured to reciprocate in alignment with the axis so that the hook can selectively pass by the second jaw and engage suture releasably supported on the first jaw;   wherein the first jaw comprises a spring for selectively binding the suture to the first jaw;   
           laying open the fibrous capsule of the hip joint;   performing a procedure on the hip joint; and   closing the fibrous capsule by suturing the fibrous capsule with the suture passer.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0083]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
           [0084]      FIGS. 1A-1D  are schematic views showing various aspects of hip motion; 
           [0085]      FIG. 2  is a schematic view showing bone structures in the region of the hip joint; 
           [0086]      FIG. 3  is a schematic anterior view of the femur; 
           [0087]      FIG. 4  is a schematic posterior view of the top end of the femur; 
           [0088]      FIG. 5  is a schematic view of the pelvis; 
           [0089]      FIGS. 6-12  are schematic views showing bone and soft tissue structures in the region of the hip joint; 
           [0090]      FIG. 13  is a schematic view showing cam-type femoroacetabular impingement (i.e., cam-type FAI); 
           [0091]      FIG. 14  is a schematic view showing pincer-type femoroacetabular impingement (i.e., pincer-type FAI); 
           [0092]      FIG. 15  is a schematic view showing a labral tear; 
           [0093]      FIGS. 16 and 17  are schematic views showing a novel suture passer formed in accordance with the present invention; 
           [0094]      FIGS. 18-38  are schematic views showing various details of the construction and operation of the distal end of the novel suture passer of  FIGS. 16 and 17 ; 
           [0095]      FIGS. 39 and 40  are schematic views showing how the novel suture passer of  FIGS. 16 and 17  can comprise a reusable tool assembly and a disposable needle assembly; 
           [0096]      FIGS. 41-50  are schematic views showing various details of the construction and operation of the reusable tool assembly and a disposable needle assembly of  FIGS. 39 and 40 ; 
           [0097]      FIGS. 50A ,  50 B and  50 C are schematic views showing an alternative form of the distal jaw spring of the novel suture passer of  FIGS. 16 and 17 ; 
           [0098]      FIGS. 50D ,  50 E and  50 F are schematic views showing another alternative form of the distal jaw spring of the novel suture passer of  FIGS. 16 and 17 ; 
           [0099]      FIGS. 51 and 52  are schematic views showing an alternative form of the outer needle of the novel suture passer of the present invention; 
           [0100]      FIGS. 53 and 54  are schematic views showing an alternative form of the inner needle of the novel suture passer of the present invention; 
           [0101]      FIGS. 55-68  are schematic views showing various details of the construction and operation of the distal end of an alternative form of the novel suture passer of the present invention; 
           [0102]      FIGS. 69-84  are schematic views showing various details of the construction and operation of the distal end of another alternative form of the novel suture passer of the present invention; 
           [0103]      FIGS. 85-89  are schematic views showing an alternative form of the distal jaw spring of the novel suture passer of  FIGS. 69-84 ; 
           [0104]      FIG. 90  is a schematic view showing another alternative construction for the novel suture passer of the present invention; 
           [0105]      FIGS. 90A ,  90 B and  90 C are schematic views showing an alternative form of the novel suture passer of the present invention; 
           [0106]      FIGS. 90D ,  90 E,  90 F,  90 G,  90 H and  90 I are schematic views showing the novel suture passer of  FIGS. 90A ,  90 B and  90 C being used to pass suture; 
           [0107]      FIGS. 91-94  are schematic views showing still another alternative construction for the novel suture passer of the present invention; and 
           [0108]      FIG. 95  is a schematic view showing another form of the novel suture passer of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0109]    Looking first at  FIGS. 16 and 17 , there is shown a novel suture passer  5  formed in accordance with the present invention. Suture passer  5  generally comprises an elongated shaft  10  having a distal jaw  15  disposed at the distal end of elongated shaft  10  and a handle  20  disposed at the proximal end of elongated shaft  10 . 
         [0110]    Looking next at  FIGS. 18-25 , distal jaw  15  is intended to releasably carry a suture  25  thereon. To this end, and as will hereinafter be discussed in further detail, distal jaw  15  has a suture slot  30  ( FIG. 18 ) formed therein. In one preferred form of the present invention, suture slot  30  is sized so that suture  25  can slide easily therein. And in one preferred form of the present invention, suture slot  30  comprises a proximal longitudinal section  35 , and intermediate diagonal section  40 , and a distal longitudinal section  45 . Distal jaw  15  also includes a slot  50  ( FIG. 20 ) at its distal end. A distal jaw spring  55  ( FIG. 19 ) is movably mounted in slot  50 . More particularly, distal jaw spring  55  is mounted to elongated shaft  10  at the proximal end of the distal jaw spring, e.g., via a pair of pins  60  extending through the proximal end of the distal jaw spring, such that the distal end of distal jaw spring  55  can flex downwardly relative to distal jaw  15 , in a cantilever fashion. A suture seat  70  ( FIG. 25 ) is disposed at the free end of distal jaw spring  55 . Suture seat  70  preferably has an inclined surface  72  thereon to act as a ramp to aid the inner needle  80  (and/or the outer needle  85 ) (see below) in displacing the distal jaw spring  55  downward during the inner and outer needles&#39; deployment stroke, as will hereinafter be discussed in further detail. Distal jaw spring  55  and suture seat  70  are sized and positioned relative to distal jaw  15  so that suture seat  70  normally protrudes across suture slot  30  under the influence of distal jaw spring  55 . However, suture seat  70  can be forced out of suture slot  30  by overcoming the bias of distal jaw spring  55 , e.g., by camming, as will hereinafter be discussed. As a result of this construction, a suture  25  disposed in suture slot  30  can be releasably held in the suture slot (and hence releasably held to distal jaw  15 ) with a light friction fit by distal jaw spring  55  and suture seat  70 . 
         [0111]    Still looking now at  FIGS. 18-25 , suture passer  5  also comprises three elements which are movable relative to elongated shaft  10  and distal jaw  15 , i.e., a proximal jaw  75 , an inner needle  80  and an outer needle  85 , with outer needle  85  being disposed co-axial with, and intermediate, inner needle  80  and proximal jaw  75 . More particularly, proximal jaw  75  includes a lumen  90  for slidably receiving outer needle  85  and inner needle  80  ( FIG. 19 ). Outer needle  85  comprises a lumen  95  for slidably receiving inner needle  80 , and includes a beveled tip  100  ( FIG. 21 ) which closely surrounds inner needle  80  ( FIGS. 21-23 ). Inner needle  80  preferably comprises a sharp distal tip  105 , an inclined surface  107  and a suture slot  110 . Suture slot  110  is preferably in the form of a “crochet hook”, in the sense that it includes a return  115  extending alongside a portion of the suture slot, whereby to provide a “crochet hook” effect for the distal end of inner needle  80 . 
         [0112]    Returning now to  FIGS. 16 and 17 , handle  20  preferably includes a grip  120  for seating in the palm of the user&#39;s hand, and a trigger  125  for actuation by the user&#39;s fingers. Handle  20  is constructed so that, by pulling trigger  125  towards grip  120 , and thereafter releasing trigger  125 , proximal jaw  75 , inner needle  80  and outer needle  85  can be moved in a sequenced manner relative to elongated shaft  10  and distal jaw  15 , and in a sequenced manner relative to one another, whereby to pass suture through tissue, as will hereinafter be discussed in further detail. Significantly, due to the construction employed by suture passer  5 , suture can be arthroscopically passed through even the tough fibrous capsule of the hip joint, whereby to permit arthroscopic suturing of the fibrous capsule. As a result, the present invention makes it more practical for a surgeon to arthroscopically operate on the hip joint by first laying open the fibrous capsule, performing the desired procedure on the hip joint, and then closing the fibrous capsule by suturing at the conclusion of the procedure. 
         [0113]    Suture passer  5  is preferably used as follows. 
         [0114]    Looking now at  FIGS. 18 and 19 , proximal jaw  75  is initially retracted proximally relative to distal jaw  15  so as to provide a gap  127  therebetween, inner needle  80  is initially retracted so that its distal end resides within lumen  90  of proximal jaw  75 , and outer needle  85  is initially retracted so that its distal end resides proximal to the distal end of inner needle  80 . A suture  25  is slipped into suture slot  30  of distal jaw  15  and then pulled distally so that the suture sits at the convergence of proximal longitudinal section  35  and intermediate diagonal section  40  of suture slot  30 —this action causes the suture to engage the inclined surface  72  of suture seat  70  and thereby drive (i.e., cam) suture seat  70  (and the free end of distal jaw spring  55 ) downwardly far enough for the suture to slip above suture seat  70 , whereupon suture seat  70  (and distal jaw spring  55 ) press upwardly so as to releasably capture suture  25  in suture slot  30  via the spring-biased suture seat  70 . 
         [0115]    With suture passer  5  in this condition, the distal end of the suture passer is ready to be advanced to the remote site where tissue is to be sutured. By way of example but not limitation, the distal end of suture passer  5  may be arthroscopically advanced to a laid-open fibrous capsule in the hip joint, in order to suture closed the laid-open fibrous capsule at the conclusion of an arthroscopic procedure. Once the distal end of suture passer  5  is disposed at the remote site, the suture passer is maneuvered so that the tissue which is to be sutured is located in the gap  127  between distal jaw  15  and proximal jaw  75 . Alternatively, and/or additionally, the tissue which is to be sutured may be maneuvered (e.g., with a supplemental tool) so that the tissue is located in the gap  127  between distal jaw  15  and proximal jaw  75 . 
         [0116]    Looking next at  FIGS. 26 and 27 , proximal jaw  75  is then advanced longitudinally towards distal jaw  15  so as to securely clamp the tissue which is to be sutured between the two jaw members. Preferably inner needle  80  and outer needle  85  are advanced in conjunction with proximal jaw  75 , in the manner shown in  FIG. 27 . 
         [0117]    Once the tissue has been securely clamped between distal jaw  15  and proximal jaw  75 , inner needle  80  and outer needle  85  are advanced together, as a unit, out of proximal jaw  75  and through the tissue. See  FIGS. 28 and 29 . As this occurs, outer needle  85  closely supports inner needle  80 , and vice-versa, thereby providing increased column strength for the two needles and permitting the two relatively thin needles to pass through tough tissue, e.g., the tough fibrous capsule of the hip. In this respect it should be appreciated that this mutual needle support (for increased column strength) is a very important aspect of the present invention, since it enables the two relatively thin needles to pass through extremely tough tissue (e.g., the fibrous capsule of the hip), tissue which neither needle could easily pass through alone, or which a single needle might pass through alone but not accurately along the desired axis of travel (e.g., the single needle might diverge from a straight path and miss a target zone on the other side of the tissue). 
         [0118]    In addition to the foregoing, it should also be appreciated that, significantly, proximal jaw  75  also supports inner needle  80  and outer needle  85  during their passage through tissue, since only short lengths of inner needle  80  and outer needle  85  extend beyond (i.e., out of) proximal jaw  75 . Again, this needle-reinforcing construction helps enable the two relatively thin needles to pass through extremely tough tissue (e.g., the fibrous capsule of the hip) which they might not otherwise be able to penetrate on their own, or which they might not otherwise be able to penetrate accurately on their own. 
         [0119]    Inner needle  80  and outer needle  85  continue to move distally as a unit until the distal tips of inner needle  80  and outer needle  85  exit the far side of the tissue and the distal tip of inner needle  80  starts to enter distal jaw  15 . At or near this point, forward advancement of outer needle  85  is stopped, and inner needle  80  advances alone. As inner needle  80  advances, its inclined surface  107  engages the inclined surface  72  of suture seat  70  and/or suture  25 , thereby causing suture seat  70  and distal jaw spring  55  to be cammed downwardly, and thereby releasing suture  25  from the capture previously provided by suture seat  70  and distal jaw spring  55  ( FIGS. 30-33 ). As this occurs, suture  25  is urged distally within suture slot  30 , with intermediate diagonal section  40  and distal longitudinal section  45  accommodating suture  25 . Inner needle  80  continues to move distally until suture slot  110  in inner needle  80  is positioned above suture  25  ( FIGS. 34 and 35 ), whereupon distal jaw spring  55  and suture seat  70  deliver suture  25  up into suture slot  110  in inner needle  80  ( FIGS. 34 and 35 ). Inner needle  80  is then retracted, carrying suture  25  with it, until suture  25  encounters the bevelled tip  100  of outer needle  85 , whereupon suture  25  is locked between the two needles ( FIG. 36 ). 
         [0120]    Then inner needle  80  and outer needle  85  are retracted proximally, as a unit, drawing suture  25  through the tissue which is clamped between distal jaw  15  and proximal jaw  75 . See  FIG. 37 . 
         [0121]    Once suture  25  has been passed through the tissue which is clamped between distal jaw  15  and proximal jaw  75 , proximal jaw  75  is retracted, thereby releasing the tissue (which has suture  25  passing therethrough) from the suture passer. See  FIG. 38 . 
         [0122]    This passed suture may then be used in ways well known in the art, e.g., so as to stitch closed a laid-open fibrous capsule. 
         [0123]    In one preferred form of the invention, and looking now at  FIGS. 39 and 40 , shaft  10 , distal jaw  15 , handle  20  and proximal jaw  75  are formed as one assembly (e.g., such as the tool assembly  130  shown in  FIGS. 39 and 40 ), and inner needle  80  and outer needle  85  are formed as another assembly (e.g., such as the needle assembly  135  shown in  FIGS. 39 and 40 ). Such a construction can be highly advantageous, since it permits tool assembly  130  to be reusable and needle assembly  135  to be disposable. 
         [0124]    In one preferred form of the invention, and looking now at  FIGS. 41-44 , needle assembly  135  comprises (i) the aforementioned outer needle  85  and a hub  140  secured to the proximal end of outer needle  85 , and (ii) the aforementioned inner needle  80  and a tab  145  secured to the proximal end of inner needle  80 . A spring  150  is disposed between hub  140  and tab  145 , so as to yieldably bias hub  140  and tab  145  away from one another. As a result, spring  150  yieldably biases inner needle  80  proximally relative to outer needle  85 , as will hereinafter be discussed in further detail. 
         [0125]    Looking next at  FIGS. 45-48 , handle  20  preferably has a needle carriage  155  movably mounted therein. Needle carriage  155  includes a tab slot  160  for receiving tab  145  of needle assembly  135 , as will hereinafter be discussed. Trigger  125  is connected to needle carriage  155  so that moving trigger  125  towards grip  120  causes needle carriage  155  to move distally relative to handle  20 . Preferably trigger  125  is connected to needle carriage  155  via a pin-and-slot mechanism, i.e., a pin  165  riding in a slot  170 . A spring  175  ( FIG. 47 ), engaging a pin  180  extending out of needle carriage  155 , biases needle carriage  155  proximally relative to handle  20  (and hence biases trigger  125  away from grip  120 ). Spring  175  ensures that needle carriage  155  is returned to the full proximal position when trigger  125  is released. 
         [0126]    Handle  20  also includes a flange seat  185  ( FIG. 45 ) movably mounted therein. Flange seat  185  is spring-mounted to needle carriage  155  so that flange seat  185  is spring-biased distally from needle carriage  155 . In one preferred form of the invention, flange seat  185  is spring-mounted to needle carriage  155  via a pair of posts  190  ( FIG. 47 ) and a pair of springs  195 . Flange seat  185  is adapted to receive a locating flange  200  on hub  140  as will hereinafter be discussed. 
         [0127]    Handle  20  also includes a proximal jaw carriage  205  ( FIG. 46 ) movably mounted therein. Proximal jaw carriage  205  is connected to the proximal end of proximal jaw  75  so that the two elements move as a unit. An extension  210  of a spring  215  is seated in an opening  220  formed in proximal jaw carriage  205  so that spring  215  biases proximal jaw carriage  205  proximally, and hence biases proximal jaw  75  proximally, as will hereinafter be discussed. 
         [0128]    Needle assembly  135  is loaded into tool assembly  130  by fitting locating flange  200  of hub  140  into flange seat  185 , and by fitting tab  145  into tab slot  160  of needle carriage  155 . See  FIG. 48 . 
         [0129]    On account of the foregoing construction, when trigger  125  is moved towards grip  120 , proximal jaw carriage  205  is moved distally by extension  210  of spring  215 , thereby causing proximal jaw  75  to move distally so as to engage tissue disposed in the gap  127  between distal jaw  15  and proximal jaw  75 . As this occurs, needle carriage  155  also moves distally, which in turn causes tab  145  (and hence inner needle  80 ) to also move distally. At the same time, due to the relative rigidity of springs  195  ( FIG. 47 ), flange seat  185  also moves distally, causing hub  140  (and hence outer needle  85 ) to also move distally, thereby causing inner needle  80  and outer needle  85  to move distally as a unit. 
         [0130]    This coordinated distal movement of proximal jaw  75 , inner needle  80  and outer needle  85  continues until the force applied to the tissue by proximal jaw  75  equates to the maximum force that spring  215  ( FIG. 46 ) can apply. Spring  215  then begins to wind up, whereupon proximal jaw carriage  205  stops moving distally (and hence proximal jaw  75  stops moving distally), while needle carriage  155  keeps moving distally, thereby causing inner needle  80  and outer needle  85  to continue moving distally, whereby to penetrate the tissue in unison. 
         [0131]    Continued movement of trigger  125  toward grip  120  causes the elements to move further distally until flange seat  185  engages a stop  225  formed in handle  20  ( FIG. 49 ), thereby preventing further distal movement of flange seat  185 , and hence preventing further distal movement of hub  140 , and hence preventing further distal movement of outer needle  85 . However, continued movement of trigger  125  toward grip  120  causes tab  145  to be moved distally ( FIG. 50 ) so as to overcome the power of spring  150  ( FIG. 44 ), so that inner needle  80  is advanced distally relative to outer needle  85 , whereby to permit inner needle  80  to engage suture seat  70 , cam it out of the way, and align its suture slot  110  with suture  25 . 
         [0132]    The amount of relative movement between inner needle  80  and outer needle  85  can be set in a variety of ways, including having flange seat  185  stop forward distal progress of needle carriage  155 . Alternatively, further movement of trigger  125  can be stopped by grip  120  at a set position so as to limit longitudinal movement of inner needle  80  relative to outer needle  85 . 
         [0133]    Releasing trigger  125  causes, sequentially, needle carriage  155  to withdraw proximally so as to permit inner needle  80  to be moved proximally by spring  150  while hub  140  (and hence outer needle  85 ) remains stationary, thereby picking up suture  25  in suture slot  110  and then capturing suture  25  between inner needle  80  and outer needle  85 . Continued release of trigger  125  causes tab  145  and hub  140  (and hence inner needle  80  and outer needle  85 ) to move proximally as a unit, and hence causes inner needle  80  and outer needle  85  to withdraw back through the tissue as a unit, carrying the suture therewith. Continued release of trigger  125  causes spring extension  210  to move proximal jaw carriage  205  proximally, whereby to withdraw proximal jaw  75  from the tissue, thereby releasing the tissue from suture passer  5 , with suture  25  extending through the tissue. 
         [0134]    It should be appreciated that the portion of distal jaw spring  55  which aids in holding suture  25  to distal jaw  15  can take many forms other than that shown in  FIGS. 24 and 25 . By way of example but not limitation, the spring surface that comes into contact with the suture can have a single tooth, multiple teeth or a roughened finish so as to promote the spring&#39;s ability to hold the suture. This portion of the distal jaw spring can also have a perpendicular surface that acts to keep suture  25  from moving distally as inner needle  80  passes over the suture. 
         [0135]    Thus,  FIGS. 50A ,  50 B and  50 C show one alternative form of distal jaw spring  55 . In this form of the invention, suture seat  70  has its inclined surface  72  formed with an arcuate configuration to receive inner needle  80  during its forward stroke, and includes teeth  226  for positively engaging suture  25  and forcing it against the opposing side wall of the suture slot. In addition, the proximal end of distal jaw spring  55  is modified so that only one pin  60  ( FIG. 19 ) is required—this pin  60  acts as a pivot pin, and clockwise motion of distal jaw spring  55  about this pivot pin is limited by a stop surface  227  which engages a corresponding stop surface on shaft  10 . 
         [0136]      FIGS. 50D ,  50 E and  50 F show another alternative form of distal jaw spring  55 . In this form of the invention, suture seat  70  has a backstop feature  228  to limit distal migration of suture  25  when inner needle  80  is driving past the suture during the needle&#39;s forward stroke. 
         [0137]    In addition to the foregoing, distal jaw spring  55  can be made from one or more materials including plastic, metal and, more specifically, superelastic materials such as Nitinol. The cantilevered portion of distal jaw spring  55  may be one material and the suture-capturing portion of the spring may be another material. 
         [0138]      FIGS. 51 and 52  show an alternative form of outer needle  85 . In this form of the invention, outer needle  85  includes a suture slot  230  at its distal end. Suture slot  230  in outer needle  85  is aligned with, and cooperates with, suture slot  110  in inner needle  80  so as to form a positive suture seat between the two needles when inner needle  80  is retracted toward outer needle  85 , whereby to securely capture suture  25  to the two needles. 
         [0139]      FIGS. 53 and 54  show an alternative form of inner needle  80 . In this form of the invention, inner needle  80  is hollow, so that objects and/or fluids can be passed through the interior of the inner needle. 
         [0140]      FIGS. 55-68  show another preferred construction for the present invention. More particularly, the construction shown in  FIGS. 55-68  is generally similar to the construction shown in  FIGS. 16-38 , except that (i) suture slot  30  comprises a proximal diagonal section  235  ( FIG. 55 ) and a distal substantially vertical section  240 , and (ii) suture seat  70  is replaced by a suture capture block  245  ( FIG. 56 ). In this form of the invention, suture  25  follows the diagonal/vertical configuration of suture slot  30 , and suture capture block  245  acts to stabilize suture  25  for positive pickup by inner needle  80 . 
         [0141]      FIGS. 69-84  show another preferred construction of the present invention. More particularly, the construction shown in  FIGS. 69-84  is generally similar to the construction shown in  FIGS. 55-68 , except that (i) distal jaw spring  55  and suture capture block  245  are replaced by a distal jaw spring  250  ( FIG. 83 ) having a suture guide slot  255  formed therein, and (ii) outer needle  85  is replaced by the outer needle  85  with suture slot  230  shown in  FIGS. 51 and 52 . In this form of the invention, suture  25  is spring-held in suture guide slot  255 , and follows the path of suture slot  30  as distal jaw spring  250  is displaced by inner needle  80 . 
         [0142]      FIGS. 85-89  show alternative constructions for releasably capturing suture  25  to distal jaw spring  250 . 
         [0143]      FIG. 90  shows another preferred construction of the present invention. More particularly, the construction shown in  FIG. 90  is generally similar to the construction shown in  FIGS. 69-84 , except that outer needle  85  lacks suture slot  230  and may or may not directly engage suture  25  and may or may not assist in capturing suture  25  to inner needle  80 . 
         [0144]      FIGS. 90A ,  90 B and  90 C show another preferred embodiment of the present invention. More particularly, in this form of the invention, outer needle  85  is formed with an inclined tip  256 , however, this inclined tip is offset 180 degrees from the inclined surface  107  of inner needle  80 , whereby to enhance suture gripping between suture slot  110  of inner needle  80  and inclined tip  256  of outer needle  85 . Furthermore, in this form of the invention, distal jaw spring  55  is omitted and suture  25  is held in suture slot  30  of distal jaw  15  by friction. 
         [0145]      FIGS. 90D ,  90 E,  90 F,  90 G and  90 I show a suture passing operation using the suture passer of  FIGS. 90A ,  90 B and  90 C. 
         [0146]    It should also be noted that inner needle  80  can be replaced by a wire with a loop on the end that can capture the suture (e.g., in the manner of a suture threader) and pull it into the outer needle. See, for example,  FIGS. 91-94 , where a wire  260 , having a hook  265 , grapples the suture and pulls it into outer needle  85 . 
         [0147]      FIG. 95  shows another preferred embodiment of the present invention. More particularly, in this form of the invention, the longitudinally-reciprocating proximal jaw  75  of the suture passer shown in  FIGS. 16 and 17  is replaced by a pivoting proximal jaw  270 . More particularly, proximal jaw  270  is mounted to elongated shaft  10  via a pivot pin  275 , such that longitudinal motion of a drive rod  280  (connected at its proximal end to proximal jaw carriage  205 ) causes proximal jaw  270  to pivot about pivot pin  275 , whereby to open and close the jaw relative to distal jaw  15 . 
       USE OF THE PRESENT INVENTION FOR OTHER APPLICATIONS 
       [0148]    It should be appreciated that the present invention may be used to arthroscopically suture the fibrous capsule of the hip joint, so as to facilitate arthroscopic procedures on the hip joint. The present invention can also be used to arthroscopically suture other tissue, both in the hip joint and in locations other than the hip joint. 
       MODIFICATIONS OF THE PREFERRED EMBODIMENTS 
       [0149]    It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.