Abstract:
An instrument for placing a graft into a bone tunnel comprises an elongated shaft having a forked distal end comprising a pair of tines. A suture spans a space defined between the tines whereby the graft may be positioned between the tines and against the suture so as to be manipulated into the bone tunnel. The tendon folds about the suture, the suture having a releasable tension such that the instrument can be removed from the bone, leaving the tendon behind without the tendon hanging up on the suture.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 13/799,527, entitled GRAFT INTRODUCER, filed Mar. 13, 2013 which is a divisional application of U.S. patent application Ser. No. 13/247,180, entitled GRAFT INTRODUCER, filed Sep. 28, 2011, now U.S. Pat. No. 8,556,970 which is incorporated herein by reference. 
    
    
     BACKGROUND 
     This application relates to tissue manipulation instruments, and more particularly to instruments for implantation of graft tissue into a bone hole. 
     In certain surgical procedures, such as tenodesis, a graft tissue is attached to a bone. For instance, in tenodesis a biceps tendon is detached from its attachment to the glenoid and is reattached to the humerus. In one popular method of reattachment a bone tunnel is created on the humerus and the detached tendon is pushed into the tunnel and then held in place via an interference bone screw implanted into the tunnel. Positioning the tendon in the tunnel can be tricky. 
     In one method, the graft tissue is externalized from the patient and whip stitched to make a stiff construct at the termination of the tissue. The stiff construct may be pushed directly into tunnel using graspers or the like. A length of suture at the distal portion of the whip stitch may be used to pull the graft tissue into the tunnel. It is desirable in many cases, however, to perform the entire operation with the graft tissue internalized within the patient. Thus, producing the whip stitch is difficult for the surgeon. 
     In another method, the graft tissue is folded near the location of tunnel and pushed into the tunnel at the fold. When using instrumentation of prior art, the graft tissue has a natural tendency to compress against the instrument. Should the frictional contact between the graft tissue and instrument be greater than the frictional contact between the graft tissue and tunnel, it is likely that the tissue will move from its desired position as the instrument is retracted from the tunnel. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes these and other limitations of the prior art in a simple and elegant design. 
     A method according to the present invention provides for implanting a graft into a bone hole. The method comprises the steps of: positioning the graft between a first tine and a second tine at a distal end of a shaft of a surgical instrument with the graft folded over a flexible member which spans a space defined between the first tine and second tine, the flexible member passing proximal of the graft; manipulating the first and second tines with the graft therebetween into a bone tunnel; pushing the graft via the flexible member into the bone tunnel; and releasing tension in the flexible member and removing the first and second tines from the bone tunnel, leaving the graft positioned therein. 
     In one aspect of the invention, a distance between the first tine and second tine, at least one of which are flexible, is controlled via tension on the flexible member. The flexible member can be received in an open distally facing notch on the first tine. In one aspect of the invention, the flexible member is released from at least one of the first tine and second tine by releasing tension on the flexible member and allowing it to fall outwardly of the open distally facing notch on the first tine. In an aspect of the invention, the first tine and second tine are manipulated toward the bone tunnel over a guide wire leading from the bone tunnel through a cannulation through the shaft. An anchor can be passed into the bone tunnel against the graft to fix the graft therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a graft implantation tool according to the present invention; 
         FIG. 2  is a side elevation view of a graft anchor for use with the tool of  FIG. 1 ; 
         FIG. 3  is a side elevation view of the tool of  FIG. 1  shown adjacent a bone tunnel and a graft ready for implantation into the tunnel; 
         FIG. 4  is a side elevation view of the tool of  FIG. 1  shown initially capturing the graft and entering the tunnel; 
         FIG. 5  is a side elevation view of the tool of  FIG. 1  shown fully inserted into the tunnel; 
         FIG. 6  is a side elevation view of the tool of  FIG. 1  shown retracting from the tunnel leaving the graft in the tunnel; 
         FIG. 7  is a side elevation view of the tool of  FIG. 1  oriented to show the graft entering the tunnel from the rear of this view and an anchor being implanted into the tunnel; 
         FIG. 8  is a side elevation view of the tunnel and graft of  FIG. 7  oriented to show the graft entering the tunnel from the left side and illustrating a completed implantation of the graft; 
         FIG. 9  is a side elevation view of an alternative embodiment of a graft implantation tool according to the present invention showing flexible tines in a relaxed state; 
         FIG. 10  is a side elevation view of the tool of  FIG. 9  showing the tines in a collapsed state; 
         FIG. 11A  is a side elevation view of a tine of  FIG. 1  showing a suture capture notch; 
         FIG. 11B  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention showing a suture capture hole; 
         FIG. 11C  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention showing an elongated suture capture hole; and 
         FIG. 11D  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention showing an alternative suture capture notch. 
         FIG. 11E  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention; 
         FIG. 11F  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention; 
         FIG. 11G  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention; and 
         FIG. 11H  is a side elevation view of a tine of an alternative embodiment of a graft implantation tool according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a graft implantation tool  10  according to the present invention. It comprises an elongated cannulated shaft  12  with a forked distal end  14 . The distal end  14  comprises a first tine  16  and second tine  18  defining a space  20  therebetween. Each of the tines  16  and  18  has a distal terminal end  22  with a distal terminal notch  24 . A length of suture  26  or other flexible material with suitable tensile strength spans the space  20  between the notches  24 . It has a first end  28  affixed to the shaft  12  where the second tine  18  meets the shaft  12 . From there it extends down along an exterior surface  30  of the second tine  18  enters the second tine notch  24 , spans the space  20 , enters the first tine notch  24  and then extends up the shaft  14  where it is secured in a suture retainer  32 , which is shown for illustrative purposes as a simple cleat but any suitable retention can be employed as will be appreciated by those of skill in the art. 
     A cannulation  34  extends axially through the shaft  12  and opens into the space  20  between the tines  16  and  18 . The cannulation  34  is wide enough to pass an interference anchor  36  (see  FIG. 2 ). The tines  16  and  18  are curved on their exterior surfaces  30  and interior surfaces  38  to fit snugly into a bone tunnel (not shown in  FIG. 1 ) and to pass the anchor  36 . One or both of the tines  16  and  18  can be flexible with their spacing being controlled by tension in the suture  26  spanning the space  20 . In such event their relaxed position is preferably slightly spread from parallel as they extend distally. This allows a more open presentation to allow easier loading of a graft (not shown in  FIG. 1 ) into the space  20 . 
     Turning also now to  FIG. 2 , the anchor  36  comprises an elongated body  40  having exterior threads  42 , a narrow distal tip  44 , a proximal tool recess  46 , such as for receipt of a hex driver, and an axial cannulation  47  for passage of a guide wire (not shown in  FIGS. 1 and 2 ). Other configurations can be employed as will be appreciated by those of skill in the art. One suitable anchor is the MILAGRO interference screw available from DePuy Mitek, Inc. of Raynham, Mass. 
     The tool  10  can be fabricated from any biocompatible materials or combinations thereof providing adequate strength for constructing the cannulated shaft  12  and having adequate elastic properties to provide the flexibility of one or both tines  16 ,  18  to accommodate variations in the distance across the space  20 . Metallic materials that can be used to manufacture the instrument of the present invention include stainless steel, titanium, alloys of nickel and titanium, or other biocompatible metallic materials. It can also be formed of polyethylene, polypropylene, PEEK, or other biocompatible non-absorbable polymers. 
     Turning also to  FIGS. 3 to 6 , use of the tool  10  will now be described.  FIG. 3  shows a biceps tendon  48  which has been removed from its placement on the glenoid (not shown) and is placed adjacent to a bone tunnel  50  which has been prepared in a humerus bone  52 . A guide wire  54  extends from the tunnel  50 . Options for creation of the bone tunnel  50  and placement of the guide wire  54  will be apparent to those of skill in the art. The tool  10  has been passed down over the guide wire  54  and is positioned adjacent to the tunnel  50 . The tendon  48  is positioned over the tunnel  50  with the suture  26  orthogonal to the tendon  48 . As the tines  16  and  18  are pressed into the tunnel  50  ( FIG. 4 ) the tendon  48  is received between the tines  16  and  18  and caught upon the suture  26  causing the tendon  48  to fold upon itself. The tendon  48  is then pressed down into the bottom of the tunnel  50  as illustrated in  FIG. 5 . At this time the suture  26  is released from the suture retainer  32  releasing tension in the suture  26  and allowing removal of the tines  16  and  18  without the suture hanging up on the tendon  48  and affecting its implantation in the tunnel  50  as illustrated in  FIG. 6 . The anchor  36  can then be implanted, preferably over the guide wire  54  employing techniques as may be known or become known to those of skill in the art. For instance,  FIG. 7  shows the anchor  36  being passed down a cannula  51  via a cannulated driver  53  and being threaded into the tunnel  50  to trap the tendon  48  therein.  FIG. 8  illustrates the completed repair. 
       FIGS. 9 and 10  illustrate an alternative embodiment of a graft implantation tool  56  according to the present invention. It has flexible first and second tines  58  and  60 , respectively, and a suture  62  passing from the second tine  60  through a distal notch  64  therein across a space  66  between the tines  58  and  60 , through a distal notch  64  in the first tine  58 . Under slack tension in the suture  62  distal ends  68  of the tines  58  and  60  spread open allowing easy entry of a graft  66  into the space  66 . Tension on the suture  62  causes the tines  58  and  60  to collapse inwardly toward each other grasping the graft  66 . The narrowing of the tine spacing may also ease its entry into a bone tunnel. 
     Although shown with tines  16  and  18  which are axially aligned with the shaft  12  they could be angled with respect to the shaft  12 . Also the shaft could be curved. Various depths of the notches  24  into the tines  16  and  18  may be employed for positioning the graft tendon  48  at different axial positions along the tines  16  and  18 . The tension on the suture  26  can also affect such placement with a bit of slack in it between the notches  24  allowing the suture  26  to bow proximally as the tendon  48  is engaged. Turning also now to  FIGS. 11A  to H, the axial notch  24  as disclosed in  FIG. 1  and  FIG. 11A  is preferred in the first tine  16  for easy release of the suture  26  from the tendon  48  after its implantation without the suture  26  catching on tendon  48  or the tine  16 . Other designs may enhance temporary holding of the suture  26  so that it does not fall out of place. For instance a closed circular hole  70 , elongated hole  72  or elongated notch  74  with a capture leg  76  or notch  80  and more aggressive capture leg  82  may be substituted especially in the second tine  18 . A notch  84  having an expanded capture leg  86  and a restriction  88  leading into the capture leg  86  allows suture to slip in easily but not slip back out. A notch  89  with a restriction  90  provides some measure of capture but still allows the suture to be extracted from the notch  89  if desired. A notch  92  can be provided with a tortuous path such as in inward spiral  94 . These designs limit suture  26  from falling out of the notch inadvertently yet still allow free sliding of the suture  26  therethrough so that it will not catch on the tendon  48  as the tines  16  and  18  are removed from the tunnel  50 . 
     The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.