Abstract:
A device for binding a cable about a fractured bone to stabilize a fracture includes a slot including a distal opening sized to receive an enlarged end of a cable and a proximal opening sized to permit the cable to slide therethrough while preventing the enlarged end from passing therethough and a bore sized to slidably receive the cable, the bore extending to a proximal opening in combination with a locking element channel extending to a distal end opening into the bore and a locking element movable into a locking position in which a distal end of the locking element extends into the bore to engage a portion of the cable received therein and lock the cable in a desired position within the bore.

Description:
PRIORITY CLAIM 
     The present application is a Continuation Application of pending U.S. patent application Ser. No. 12/521,842 filed on Jun. 30, 2009; which is a 371 application of PCT Application Serial No. PCT/US2008/055226 filed on Feb. 28, 2008; which claims the benefit of the U.S. Provisional Patent Application Ser. No. 60/903,823 filed on Feb. 28, 2007. The disclosures of the above applications/patents are incorporated herein by reference 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to orthopedics, in particular, to a crimp used to hold surgical cable after it has been looped around a fractured bone. 
     BACKGROUND OF THE INVENTION 
     It is well known to use surgical cable and crimp assemblies to fix parts of a fractured bone and to join them together until the bone heals. Surgical procedures on and in the vicinity of a bone with closely neighboring nerves, arteries, muscle, ligaments, complicated anatomical structures and delicate areas represent a difficult and time consuming task for the surgeon. Thus it is important for the cable and crimp device to be assembled accurately, minimizing stress, trauma, risk, and injury to a patient while facilitating and shortening the procedure. 
     Furthermore it is desirable to maintain the bulk of the cable as well as the joint where the cable is affixed to itself as compact as possible to minimize discomfort and damage to the surrounding tissue. 
     Known minimally invasive techniques for such procedures generally involve looping the cable, isolated from the crimp member, about the bone and then inserting a beaded first end of the cable into a cavity of a groove in the crimp member. The groove at the crimp member allows the first end of the cable to slide in place until the bead locks in its final position. The second end of the cable is then inserted through the hole of the crimp member and the cable is tensioned by application of a tensioning tool to the cable through a handle, to a proximal abutment face of the crimp. Once the desired final tension has been established, the set screw is tightened using a screwdriver through the handle, deforming the cable inside the hole. The tensioning tool is then removed and the free end of the cable extending from the proximal abutment face of the crimp is cut off. 
     Many of the known tools for performing this procedure require pulling the cable from both ends after the cable has been looped around the bone. To access both ends of the cable as required, such devices require significant spreading of the incision and the tissue along the path of the cable increasing trauma to muscle and other surrounding tissue and making them unsuitable for use in restricted areas. Such devices are disclosed, for example, in U.S. Pat. Nos. 5,649,927 and 6,017,347. 
     Other devices such as that described in allow tensioning of the cable by application of a tensioning tool to one of the cable ends and to an abutment face of the crimp by employing a surgical cable factory crimped to one of the holes of the crimp, as those disclosed in U.S. Pat. Nos. 5,423,820, 6,007,268 and 6,387,099. The same effect is achieved by instruments such as that described in U.S. Pat. No. 6,017,347, that use a wire with a beaded end which locks into an end of the crimp preventing the wire from slipping out of the clamp. The bead locks into the end of the crimp preventing the wire from sliding out of the crimp. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a compact tool which is easy to assemble and use to secure surgical cable around bone without requiring a large incision and which minimizes the exposure or stripping of musculature away from the bone. 
     Furthermore, it is an object of the present invention to provide a cable and crimp assembly that enables the cable to be inserted isolated from the crimp member, and the crimp member to be attached to the surgical cable only after the cable has been looped around the bone. 
     The embodiments of the present invention comprise a flexible cable, a crimp member, a set screw, a handle, and a screw-driver. The surgical cable has an enlargement (e.g., a bead) affixed to its first end and the crimp member has a two-part groove, a cable hole for the cable and an oblique threaded hole for a set screw. The groove has a first part including a cavity sized to accept the beaded end of cable. The second part of groove is sized to allow the flexible cable to pass therethrough while stopping the larger, beaded first end of the cable. The cable hole is sized to accommodate the cable while the oblique threaded hole extends to the cable with an abutment, proximal face of the crimp member located near a proximal end of the cable hole. 
     The present invention is also directed to a device for binding a cable about a fractured bone to stabilize a fracture comprising a slot including a distal opening sized to receive an enlarged end of a cable and a proximal opening sized to permit the cable to slide therethrough while preventing the enlarged end from passing therethough and a bore sized to slidably receive the cable, the bore extending to a proximal opening in combination with a locking element channel extending to a distal end opening into the bore and a locking element movable into a locking position in which a distal end of the locking element extends into the bore to engage a portion of the cable received therein and lock the cable in a desired position within the bore. 
     Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred features of the present invention are disclosed in the accompanying drawings, wherein similar reference characters denote similar elements throughout the several views, and wherein: 
         FIG. 1  shows a side view of a crimp device according to the first embodiment of the present invention, prior to assembling with a flexible cable; 
         FIG. 2  shows a top view of the crimp device of  FIG. 1 ; 
         FIG. 3  shows a proximal view of the crimp device of  FIG. 1 ; 
         FIG. 4  shows a perspective view of the crimp device of  FIG. 1 ; 
         FIG. 5  shows a side view of a disassembled system for fixing a cable about a fractured bone including the crimp device of  FIG. 1 ; 
         FIG. 6  shows a top view of the system of  FIG. 5 ; 
         FIG. 7  shows a first perspective view of the system of  FIG. 5 ; 
         FIG. 8  shows a second perspective view of the system of  FIG. 5 ; 
         FIG. 9  shows a side view of a set screw for use with a crimp device according to the invention; 
         FIG. 10  shows a proximal view of the set screw of  FIG. 9 ; 
         FIG. 11  shows a perspective view of the set screw of  FIG. 9 ; 
         FIG. 12  shows a proximal view of a crimp device according a second embodiment of the present invention, prior to assembling with a flexible cable; 
         FIG. 13  shows a top view of the crimp device of  FIG. 12 ; 
         FIG. 14  shows a side view of the crimp device of  FIG. 12 ; 
         FIG. 15  shows a perspective view of the crimp device of  FIG. 12 ; 
         FIG. 16  shows a side view of a system for fixing a cable about a fractured bone including the crimp device of  FIG. 12  in a partially assembled state; 
         FIG. 17  shows a perspective view of the system of  FIG. 16  in a partially assembled state; 
         FIG. 18  shows a side view of the system of  FIG. 16  in a fully assembled state; and 
         FIG. 19  shows a perspective view of the system of  FIG. 16  in a fully assembled state. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, an apparatus and method for securing surgical cable around a bone according to the preferred embodiment of the present invention will be explained with reference to  FIGS. 1-6 . As would be understood by those skilled in the art, the term ‘proximal’ describes a direction approaching a user (e.g., a surgeon) along the item being described while the term ‘distal’ refers to a direction away from the user along the item being described. Thus, the distal end of a cable refers to an end of the cable furthest from an end extending, for example out of the body to a point accessible to a user, along the cable and not to a portion of the cable located physically furthest from the operator. 
     As shown in  FIGS. 1-4  a binding member  10  according to a first embodiment of the present invention includes an outer surface  12 , a bone facing surface  14 , a distal end  16  and an abutment surface  18  formed at a proximal end  20  thereof. A groove  22  is formed in the binding member  10  extending distally at an angle from a proximal opening  24  in the abutment surface  18  adjacent to the bone facing surface  14  to a distal end  26 . A bore  28  extends from a proximal opening  30  at the distal end  26  of the groove  22  to a distal opening  32  in the distal end  16 . The bore  28  is preferably formed as a simple through hole sized to accept a flexible cable  34  to be held by the binding member  10 . The groove  22  according to this embodiment is formed as a two-part slotted hole open at the outer surface  12 . The proximal opening  24  of the groove  22  is preferably sized so that the cable  34  may slidably pass therethrough while an enlarged first end  36  of the cable  34  is prevented from passing therethrough. The groove  22  may also include a lip  38  (shown in  FIG. 2  as the space between the broken lines and the unbroken lines of the groove  22 ) extending substantially around the perimeter thereof sized to permit the cable  34  to pass slidably therethrough while preventing the enlarged first end  36  from passing through. The rest of the groove  22  (i.e., an interior passage thereof) is preferably sized to permit the cable  34  and the enlarged first end  36  to slide therethrough. In addition, the groove  22  includes an enlarged distal opening  40  at the distal end  26  sized to permit the enlarged first end  36  to be inserted into the groove  22 . 
     The binding member  10  further comprises a locking element channel  42  extending at an angle from a proximal opening  44  to a distal opening  46  into the bore  28 . As would be understood by those skilled in the art, although the locking element channel  42  is described in conjunction with the disclosed embodiments as receiving a set screw, any number of alternate locking elements may be employed to lock the cable  34  at a desired position in the bore  28  (i.e., to maintain a desired tension thereon) as will be described in more detail below. For example, the locking element may include an interference fit plug, a tube that is crushed, etc. or any other suitable device. As can be seen in  FIG. 4 , a proximal part of the channel  42  may include a thread  48  sized to mate with the thread  52  of a corresponding part of a set screw  50  as shown in  FIGS. 9-11 . A proximal end of the set screw  50  preferably includes a structure (e.g., a hex recess  51 ) to mate with a known tightening device (not shown) such as a screw driver, hex wrench, etc. 
     As shown in  FIGS. 5-8 , an apparatus for implanting a binding device  10  includes a mating element  54  including a first channel  56  which, when the element is in a desired position, is aligned with the bore  28  and a second channel  58  including a distal portion  60  which, when in the desired position, is aligned with the channel  42  and a proximal portion  62  which, in this embodiment, extends proximally from a proximal end of the distal portion  60  angled back toward the channel  56  to reduce a profile of the mating element  54 . As would be understood by those skilled in the art, the angle between the proximal and distal portions  62 ,  60 , respectively, should preferably be no more than 20° to avoid impeding the operation of the universal joint in a tightening tool to be inserted therethrough as will be described below. Furthermore, a maximum width of the element  54  is preferably no more than 8 mm to minimize trauma to surrounding tissue. The element  54  also includes an abutting surface  64  which, when the element  54  is in the desired position, contacts the abutment surface  18 . 
     In use, the cable  34  is first passed around the portion(s) of fractured bone to be stabilized and the enlarged first end  36  is inserted into the groove  22  via the opening  40 . The cable  34  and the enlarged first end  36  are then drawn through the groove  22  until contact between the enlarged first end  36  and the lip  38  prevents the enlarged end  36  from moving further. The second end of the cable  34  is then inserted into the distal opening  32  and passed through the bore  28  out of the proximal opening  30  and into the groove  22 . The second end of the cable  34  is drawn out of the proximal opening  24  and the slack in the cable  34  is drawn out by pulling the cable  34  proximally out of the opening  24 . The second end of the cable  34  is then inserted into the channel  56  and passed therethrough to a known tensioning mechanism (not shown) as the mating element  54  is moved distally over the cable  34  until the abutting surface  64  contacts the abutment surface  18 . The tensioning mechanism is then operated as would be understood by those skilled in the art until a desired tension is placed on the cable  34 . A tightening device including a joint (e.g., a universal joint) allowing the tightening device to navigate the bend in the channel  58  is then inserted through the channel  58  to mate with the hex recess  51 . The set screw  50  is then screwed into the channel  42  until a distal end thereof extends into the bore  28  locking the cable  34  in position therein and maintaining the desired tension in the cable  34 . The second end of the cable  34  may then be released from the tensioning mechanism and the portion of the cable  34  extending proximally from the groove  22  may be cut off and withdrawn from the body. 
     As shown in  FIGS. 12-19 , a binding member  100  according to a second embodiment of the invention operates in a manner substantially similar to that of the binding member  10  described above. Similar to the binding member  10 , the binding member  100  includes an outer surface  112 , a bone facing surface  114 , a distal end  116  and an abutment surface  118  formed at a proximal end  120  thereof. A groove  122  is formed in the binding member  100  extending distally from a proximal opening  124  in the abutment surface  118  to a distal end  26 . However, in the binding member  100 , the bore  128  does not open into the groove  122 . Rather, the bore  128  extends from a proximal opening  130  in proximal end  120  to a distal opening  132  in the distal end  116 . The bore  128  is preferably formed as a simple through hole sized to accept a flexible cable  34  to be held by the binding member  100 . The proximal opening  124  of the groove  122  is sized so that a cable  134  may slidably pass therethrough while an enlarged first end  136  of the cable  134  is prevented from passing therethrough. The groove  122  also includes a lip  138  extending substantially around the perimeter thereof sized to permit the cable  134  to pass slidably therethrough while preventing the enlarged first end  136  from passing through. The rest of the groove  122  (i.e., an interior passage thereof) is preferably sized to permit the cable  134  and the enlarged first end  136  to slide therethrough. In addition, the groove  122  includes an enlarged distal opening  140  at a distal end  126  thereof sized to permit the enlarged first end  136  to be inserted into the groove  122 . As the bore  128  does not open into the groove  122 , the groove  122  does not need to be angled relative to the outer surface  112  and the bone facing surface  114 . Rather, the groove  122  may extend substantially parallel to these surfaces allowing the thickness of the binding member  100  to be reduced. 
     The binding member  100  further comprises a locking element channel  142  extending at an angle from a proximal opening  144  to a distal opening  146  into the bore  128 . As described above in regard to the binding member  10 , although the channel  142  is shown as adapted to receive a set screw  50  as shown in  FIGS. 9-11 , any number of alternate locking elements may be employed to lock the cable  134  at a desired position in the bore  128  (i.e., to maintain a desired tension thereon). A proximal end of the set screw  50  preferably includes a structure (e.g., a hex recess  51 ) to mate with a known tightening device (not shown) such as a screw driver, hex wrench, etc. 
     As shown in  FIGS. 16-19 , an apparatus for implanting a binding device  100  includes a mating element  154  including a first channel (not shown) which, when the element  154  is in a desired position, is aligned with the bore  128  and a second channel (not shown) which may include an angled proximal section to reduce the profile of the element  154  similar to the distal portion  60  of the element  54  described above. The distal portion of this second channel, when in the element  154  is in the desired position, is aligned with the channel  142 . The element  154  also includes an abutting surface  164  which, when the element  154  is in the desired position, contacts the abutment surface  118 . 
     In use, the cable  134  separate from the binding member  100  is inserted around the bone to be cerclaged as would be understood by those skilled in the art and the enlarged first end  136  is inserted into the groove  122  via the opening  140 . The cable  134  and the enlarged first end  136  are then drawn through the groove  122  until contact between the enlarged first end  136  and the lip  138  prevents the enlarged end  136  from moving further. The second end of the cable  134  is then inserted into the distal opening  132  and passed through the bore  128  out of the proximal opening  130 . The slack in the cable  134  is drawn out by pulling the cable  134  proximally out of the opening  130  and the second end of the cable  134  is inserted into the channel  156  and passed therethrough to a known tensioning mechanism (not shown) as the mating element  154  is moved distally over the cable  134  until the abutting surface  164  contacts the abutment surface  118 . The tensioning mechanism is then operated as would be understood by those skilled in the art until a desired tension is placed on the cable  134 . As described above in regard to element  54 , a tightening device is inserted through the second channel to mate with the hex recess  51 . The set screw  50  is then screwed into the channel  142  until a distal end thereof extends into the bore  128  locking the cable  134  in position therein and maintaining the desired tension in the cable  134 . The second end of the cable  134  may then be released from the tensioning mechanism and the portion of the cable  34  extending proximally from the opening  130  may be cut off and withdrawn from the body. 
     The present invention has been described with reference to specific exemplary embodiments. Those skilled in the art will understand that various modifications and changes may be made to the embodiments without departing from the teaching of the invention. These embodiments specification are therefore, to be regarded in an illustrative rather than a restrictive sense and are not intended to limit the scope of the invention which is intended to cover all modifications and variations of this invention that come within the scope of the appended claims and their equivalents.