Abstract:
The present disclosure relates to a method of creating a bone tunnel during ligament reconstruction surgery. The method includes placing a guide wire through the femur, the guide wire having a first end portion including a pointed tip and a second end portion; placing a drill mechanism over the first end portion of the guide wire, the drill mechanism having a first end portion including a drill bit and a second end portion including an attachment portion; coupling an adaptor assembly to the attachment portion, the adaptor assembly including a shaft; coupling a drill to the shaft and operating the drill to create a tunnel in the femur; coupling a drill bit assembly to the second end portion of the guide wire and locating the assembly against the drill bit of the attachment portion; and operating the drill to create a counter bore within the tunnel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of co-pending U.S. patent application Ser. No. 12/399,397, entitled “RETRODRILL SYSTEM,” filed Mar. 6, 2009 which claims the benefit of U.S. Patent Application No. 61/034,189, filed Mar. 6, 2008, the disclosures of which are incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Field of Technology 
     The present disclosure relates to the creation of bone tunnels during ligament reconstruction surgery, and more specifically, the creation of femoral bone tunnels. 
     2. Related Art 
     For torn knee ligament reconstruction, there has been an evolution in the anatomic femoral placement of the tissue graft. This can be accomplished by several methods all of which provide the ability to create a tunnel socket from the inside to the outside of the femur. Without hyperflexing the knee, a curved drilling path is needed to accomplish this procedure. A curved guide wire is first placed through the femur to act as a guide pin. An appropriate sized reamer is then advanced over the guide wire to create a drilled bone tunnel. A shortcoming of one of the present methods is the size of the reamer. The flexible reamers that are currently produced can&#39;t easily be made smaller than 7 mm. The size of the bone tunnel is important for proper placement of the tissue graft and for maintaining the tissue graft within the tunnel. 
     SUMMARY 
     In one aspect, the present disclosure relates to a method of creating a bone tunnel during ligament reconstruction surgery. The method includes placing a guide wire through a femur, the guide wire having a first end portion including a pointed tip and a second end portion; placing a drill mechanism over the first end portion of the guide wire, the drill mechanism having a first end portion including a drill bit and a second end portion including an attachment portion; coupling an adaptor assembly to the attachment portion, the adaptor assembly including a shaft; coupling a drill to the shaft and operating the drill to create a tunnel in the femur; coupling a drill bit assembly to the second end portion of the guide wire and locating the drill bit assembly against the drill bit of the attachment portion; and operating the drill to create a counter bore within the tunnel. 
     In another aspect, the present disclosure relates to a drill mechanism. The drill mechanism includes a first end portion including a drill bit; and a second end portion including an attachment portion, the attachment portion including a first set of slots positioned on opposite sides of the portion and extending parallel with a longitudinal axis of the mechanism, the first set of slots including a first end and a second end, and a second set of slots located at the second end of the first set of slots, the second set of slots extending perpendicular to the first set of slots. 
     In yet another aspect, the present disclosure relates to an adaptor assembly for a drill mechanism. The adaptor assembly includes an adaptor including a housing and a shaft coupled to the housing, the housing including a wall, a first pin disposed through the wall, and a second pin disposed through the wall opposite the first pin; a ring disposed within the shaft; a collar coupled to the shaft; and a nut coupled to the housing of the adaptor, the nut including an opening through which the shaft is disposed. In an embodiment, the adaptor assembly further includes a drill mechanism disposed within the housing of the adaptor, the drill mechanism including an attachment portion including a set of slots, the drill mechanism disposed within the housing such that the first pin and the second pin are housed within the set of slots. 
     In a further aspect, the present disclosure relates to drill bit assembly. The drill bit assembly includes a housing; a knob coupled to the housing; and a locking mechanism disposed within a cavity of the housing, the locking mechanism comprising a shaft, a first finger coupled to the shaft, a second finger coupled to the shaft, and a detent located between the first finger and the second finger, wherein the locking mechanism is movable within the cavity. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present disclosure and together with the written description serve to explain the principles, characteristics, and features of the disclosure. In the drawings: 
         FIG. 1  shows placement of a guide wire of the present disclosure through a femur. 
         FIG. 2  shows the guide wire of the present disclosure. 
         FIG. 2A  shows the first end portion of the guide wire of  FIG. 2 . 
         FIG. 3  shows placement of a drill mechanism of the present disclosure over the first end portion of the guide wire of the present disclosure. 
         FIG. 4  shows the drill mechanism of the present disclosure. 
         FIG. 4A  shows the attachment portion of the drill mechanism of the present disclosure. 
         FIG. 5  shows creation of a bone tunnel through the femur using the drill mechanism of  FIG. 4 . 
         FIG. 6  shows an exploded view of the adaptor assembly of the present disclosure. 
         FIG. 7A  shows a cross-sectional view of the adaptor assembly of the present disclosure. 
         FIG. 7B  shows another cross-sectional view of the adaptor assembly of the present disclosure. 
         FIG. 8  shows attachment of a drill bit assembly of the present disclosure to the guide wire of  FIG. 2 . 
         FIG. 9A  shows the second end portion of the guide wire of  FIG. 2  and the drill bit assembly of  FIG. 8 . 
         FIG. 9B  shows coupling of the second end portion of the guide wire to the drill bit assembly. 
         FIG. 9C  shows placement of the second end portion of the guide wire within the drill bit assembly. 
         FIG. 10  shows a cross-sectional view of the drill bit assembly of  FIG. 8 . 
         FIG. 11  shows the drill bit assembly of  FIG. 8  abutting the drill bit of the drill mechanism of  FIG. 4 . 
         FIG. 12  shows creation of a counter bore in the femoral bone tunnel using the drill bit assembly. 
         FIG. 13  shows the femoral bone tunnel and the counter bore. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. 
       FIG. 1  shows a knee joint  10  including a femur  20  and a tibia  30 , and specifically, insertion of a guide wire  40  into the femur  20  via use of a drill guide  50  and a drill (not shown). The guide wire  40  will be used, in combination with the drill, to drill a tunnel into the femur  20  in preparation for receipt of a tissue graft, as will be further described below. Prior to inserting the guide wire  40  into the femur  20 , the surgeon views the femur  20  arthroscopically and determines the best location for inserting the guide wire  40 . Subsequently, the surgeon inserts a cannulated shaft  51  of the guide  50  into the joint  10  and positions a distal end  51   a  of the shaft  51  against the femur  20 . The shaft  51  includes the distal end  51   a  and a proximal end  51   b . The distal end  51   a  is curved and the proximal end  51   b  is coupled to a handle  52 . 
     After positioning the shaft  51  against the femur  20 , the guide wire  40  is then inserted through the shaft  51 . As shown in  FIGS. 2 and 2A , the guide wire  40  includes a first end  41  having a pointed tip  41   a  and a second end  42 . The second end  42  is coupled to a drill (not shown) and the drill is operated to insert the guide wire  40  through the femur  20 . The guide wire  40  includes a flexible metal material, such as nitinol or other flexible metal material, which allows the first end  41  of the wire  40  to bend along the curved distal end  51   a  of the shaft  50  and be inserted into the femur  20  along the desired tunnel path. 
     Once the first end  41  of the wire  40  has been inserted through the femur  20 , a cannulated drill mechanism  60  is positioned over the first end  41 , as shown in  FIG. 3 . The drill mechanism  60 , as shown in  FIGS. 4 and 4A , includes a first end  61  having an attachment portion  62  and a second end  63  having a drill bit  64 . The attachment portion  62  includes a first set of slots  62   a , wherein the slots  62   a  are positioned on opposite sides of the portion  62  and extend parallel with a longitudinal axis L of the mechanism  60 . Each of the slots  62   a  includes a first end  62   a ′ and a second end  62   a ″. A second set of slots  62   b  are located at the second end  62   a ″ of the first set of slots  62   a . The second set of slots  62   b  extends perpendicular to the first set of slots  62   a . The purpose of the slots  62   a , 62   b  will be further described below. For the purposes of this disclosure, the drill bit  64  is 4.5 mm in diameter. However, the size of the drill bit  64  may vary based on surgeon preference and the size of the femoral tunnel. 
     As shown in  FIG. 5 , after the mechanism  60  is positioned over the first end  41  of the wire  40 , an adaptor assembly  70  is coupled to the mechanism  60  and the wire  40 . The adaptor assembly  70 , as shown in  FIG. 6 , includes an adaptor  71  having an outer surface  71   a , an inner surface  71   b , a wall  71   h  located between the inner and outer surfaces  71   a , 71   b , a first end  71   c , a second end  71   d  having threads  71   d ′, a first pin  71   e  disposed through the wall  71   h  of the adaptor  71  and a second pin  71   f  disposed through the wall  71   h  opposite the first pin  71   e , and a cannulated shaft  71   g  coupled to the inner surface  71   b  of the adaptor  71 . A coiled spring  72  is disposed on the shaft  71   g  of the adaptor  71  and a ring  73  is disposed within the cavity  71   g ′ of the shaft  71   g . The ring  73  includes a first portion  73   a  having channels  73   a ′ that divide the first portion into sections  73   a ″, a second portion  73   b , and an annular depression  73   c  located between the first and second portions  73   a , 73   b.    
     As shown in  FIGS. 6 ,  7 A, and  7 B, a collar  74  is coupled to the shaft  71   g  and ring  73  via screws  74   a  that extend through openings  74   b  in the collar  74 , through the openings  71   j , and into the annular depression  73   c . Each screw  74   a  has a first end  74   a ′ that abuts the annular depression  73   c  of the ring  73  and a second end  74   a ″. A nut  75  is coupled to the second end  71   d  of the adaptor  71  and covers the coiled spring  72 , the ring  73 , and the collar  74 . The nut  75  includes an outer surface  75   a , an inner surface  75   b  having threads  75   b ′, and an opening  75   c . A retaining ring  76  is located on the shaft  71   g  behind the opening  75   c . The nut  75  is coupled to the second end  71   d  of the adaptor  71  via engagement between the threads  71   d ′, 75   b ′ of the adaptor  71  and the inner surface  75   b  of the nut  75 . 
     The adaptor assembly  70  is disposed on the attachment portion  62  of the mechanism  60  such that the first pin  71   e  and the second pin  71   f  are inserted into the first set of slots  62   a . The adaptor assembly  70  is then rotated to insert the pins  71   e , 71   f  within the second set of slots  62   b  and thereby couple the adaptor assembly  70  to the mechanism  60 . At the same time that the adaptor assembly  70  is disposed on the attachment portion  62 , the shaft  71   g  and ring  73  are disposed over the guide wire  40 , as shown in  FIG. 7A . Upon rotation of the nut  75 , the inner surface  75   b  of the nut  75  abuts the collar  74  and causes the collar  74  to move longitudinally, thereby causing the ring  73  to move longitudinally with the nut  75 . As is shown in  FIG. 7B , during continued rotation of the nut  75 , the first portion  73   a  of the ring  73  engages a beveled portion  71   g ″ of the cavity  71   g ′, and causes the sections  73   a ″ of the first portion  73   a  to be reduced and engage the guide wire  40 , thereby locking the adaptor assembly  70  to the guide wire  40 . The spring  72  maintains tension on the collar  74  and, as shown in  FIG. 7B , is compressed as the collar  74  moves longitudinally. 
     After the adapter assembly  70  is coupled to the mechanism  60  and wire  40 , a drill is coupled to the shaft  71   g  and operated to create a tunnel within the femur  20 . Once the drill bit  64  exits the femur  20  and the tunnel is created, operation of the drill is discontinued. As shown in  FIG. 5 , the second end  42  of the guide wire  40  is extended from the second end  63  of the mechanism  60  by rotating the nut  75  to disengage the ring  73  from the guide wire  40  and pulling on the second end  42  of the guide wire  40 . As shown in  FIG. 8 , a drill bit assembly  80  is then coupled to the second end  42  of the guide wire  40 . The drill bit assembly  80 , as shown in  FIGS. 9A and 10 , includes a housing  81  and a knob  82  coupled to the housing  81  via a pin  83 . The housing  81  includes an inner cavity  81   a . Disposed within the cavity  81   a  is a locking mechanism  84 . The locking mechanism  84  includes a shaft  84   a , a first  84   b  and second  84   c  finger coupled to the shaft  84   a , and a detent  84   d  located between the fingers  84   b , 84   c  and the shaft  84   a . A spring  85  is disposed around the shaft  84   a . The shaft  84   a  includes a dimple  84   a ′ and each finger  84   b , 84   c  includes a rim  84   b ′, 84   c ′. The surface  81   a ′ of the inner cavity  81   a  includes a detent ball  86 . 
     As shown in  FIGS. 9A and 9B , the second end  42  of the guide wire  40  includes grooves  42   a  and a tip  42   b . For the purposes of  FIG. 9A , only one groove  42   a  is shown. However, a second groove is present opposite the groove  42   a  shown in  FIG. 9A . The drill bit assembly  80  is coupled to the second end  42  such that the tip  42   b  is disposed within the detent  84   d  and the rims  84   b ′, 84   c ′ are disposed within the grooves  42   a . After coupling of the drill bit assembly  80  to the second end  42 , the second end  42  and locking mechanism  84  are pushed into the inner cavity  81   a  of the housing  81  such that the spring  85  is compressed and the knob  82  is then rotated to dispose the detent ball  86  within the dimple  84   a ′, thereby fixating the drill bit assembly  80  to the guide wire  40 , as shown in  FIGS. 9B &amp; 9C . 
     As shown in  FIG. 11 , after coupling of the drill bit assembly  80  to the guide wire  40 , the wire  40  is inserted back into the mechanism  60  until the drill bit assembly  80  abuts the drill bit  64  of the drill mechanism  60 . The nut  75  is rotated until the ring  73  engages the wire  40  and locks the adaptor assembly  70  to the wire  40 . A drill is then coupled to the shaft  71   g  and, upon operation of the drill, the mechanism  60 , and thereby the drill bit assembly  80  is rotated to drill a certain depth and create a counter bore  100  along the tunnel  90 , as is shown in  FIGS. 12  &amp; 13 . The depth will vary based on surgeon preference and the size of the tissue graft. Having two areas of different diameter allows the tissue graft to remain in the larger area, i.e. the counter bore  100 , and substantially reduces the possibility of the tissue graft extending out of the smaller area, i.e. the tunnel  90 , due to the smaller size. 
     For the purposes of this disclosure, the drill bit assembly  80  has a diameter of 6 mm. However, the diameter may vary based on surgeon preference and desired size of the counter bore  100 . The drill guide  50 , drill mechanism  60 , adaptor assembly  70 , anchor assembly  80 , and their components are made from biocompatible metal or non-metal material, such as stainless steel, titanium alloy, polymer, or other material, and may be made via a variety of molding and/or machining process known to those of ordinary skill in the art. In addition, while not shown in the figures, it is within the scope of this disclosure that the first end portion  41  of the guide wire  40 , when inserted through the femur  20 , is also inserted through the patient&#39;s skin. 
     As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the disclosure, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.