Intramedullary implant for fracture fixation and method of using the same

Abstract

An intramedullary implant, useful particularly for the fixation of fractures of the radius, the implant comprising a first and second end, both ends configured for entry into the intramedullary canal through an entry point on the bone, such as the fracture site, and configured for positioning within the intramedullary canal of the fractured bone, the first end positioned in the intramedullary space of a first bone fragment and the second end positioned in the intramedullary space of a second bone fragment on the opposite side of the fracture. The first end is positioned by displacing the implant in a first direction and the second end is positioned by displacing the implant in a second direction, substantially opposite to the first direction. The implant further comprises a tip configured to abut an end surface of the second fragment to provide axial support to second fragment.

1 ) A fracture fixation implant for fixation of a broken bone comprising a fracture site, a first and second fragment on opposing sides of the fracture site, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the implant comprising: 
 a first end configured to be placed in the intramedullary space of the first fragment;    a second end configured to be placed in the intramedullary space of the second fragment; and    a form configured to enable placement of the first end in a first direction into the intramedullary space of the first fragment through an entry point on the broken bone and further configured to enable displacement of the implant in a second direction substantially opposite the first direction and across the fracture site to enable placement of the second end into the intramedullary space of the second fragment.    
   
   
       2 ) The implant of  claim 1  wherein the first fragment is at a central portion of the bone and the second fragment is at an end portion of the bone, wherein the implant further comprises a tip at the second end configured to abut the end portion of the second fragment and to enable axial loading of the implant at the tip.  
   
   
       3 ) The implant of  claim 2  wherein the tip resists side-to-side displacement of the second fragment.  
   
   
       4 ) The implant of  claim 2  wherein the end portion comprises an endosteal surface having a contour and the tip is contoured to largely conform to the contour of the endosteal surface.  
   
   
       5 ) The implant of  claim 4  wherein the surface contour of the tip is large enough to spread the axial load on the implant at the second end over a large contact area.  
   
   
       6 ) The implant of  claim 2  further comprising a longitudinal receptor disposed at the tip and configured to capture a fastener to releasably mate the implant to the end portion and fix the bone to the tip.  
   
   
       7 ) The implant of  claim 6  wherein the fastener comprises a bone screw.  
   
   
       8 ) The implant of  claim 6  wherein the longitudinal receptor is further configured to receive a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       9 ) The implant of  claim 1  wherein the bone comprises the radius and the fracture is a distal radius fracture.  
   
   
       10 ) The implant of  claim 1  further comprising at least one cross-locking receptor disposed on the second end.  
   
   
       11 ) The implant of  claim 10  wherein the cross locking receptor is directed volarly.  
   
   
       12 ) The implant of  claim 11  wherein the direction is approximately 17 degrees volar.  
   
   
       13 ) The implant of  claim 10  wherein the cross locking receptor is directed dorsally.  
   
   
       14 ) The implant of  claim 13  wherein the direction is approximately 12 degrees.  
   
   
       15 ) The implant of  claim 10  in which said cross locking receptor is angled distally.  
   
   
       16 ) The implant of  claim 10  in which said cross locking receptor is angled proximally.  
   
   
       17 ) The implant of  claim 10  wherein the cross-locking receptor is configured to capture a fastener, the fastener configured to extend through the cross-locking receptor and engage the bone of the second fragment to securely position the implant within the second fragment.  
   
   
       18 ) The implant of  claim 17  in which the cross-locking receptor is threaded and the fastener is threaded to threadably engage the cross-locking receptor.  
   
   
       19 ) The implant of  claim 10  wherein the second end has a receptor configured to receive a driver configured to facilitate insertion of the implant into the intramedullary space.  
   
   
       20 ) The implant of  claim 19  wherein the cross-locking receptor and the receptor configured to receive the driver configured to facilitate insertion of the implant into the intramedullary space are the same.  
   
   
       21 ) The implant of  claim 1  further comprising a receptor for receiving a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       22 ) The implant of  claim 21  wherein the implant further comprises a tip at the second end and the receptor is disposed on the tip.  
   
   
       23 ) The implant of  claim 21  wherein the receptor is disposed on the periphery of the second end of the implant.  
   
   
       24 ) The implant of  claim 1  further comprising at least one receptor disposed on a peripheral surface of the first end of the implant, the receptor configured to capture a fastener, said fastener configured to extend through the receptor and engage the bone of the proximal fragment to securely position the implant within the first fragment.  
   
   
       25 ) The implant of  claim 1  wherein the implant has largely a banana shape.  
   
   
       26 ) The implant of  claim 1  wherein the implant has a largely S shape.  
   
   
       27 ) The implant of  claim 1  wherein the entry point comprises an extended opening from the fracture site.  
   
   
       28 ) The implant of  claim 1  wherein the first end and the second end are formed as a single piece.  
   
   
       29 ) The implant of  claim 1  wherein the first end and the second end are formed separate pieces adjoined together to form a unitary implant.  
   
   
       30 ) The implant of  claim 29  wherein the first end comprises a tongue and the second end comprises a groove configured to receive and capture the tongue of the first end.  
   
   
       31 ) The implant of  claim 29  wherein the first end and the second end are secured together by a fastener.  
   
   
       32 ) The implant of  claim 31  wherein the fastener comprises a screw.  
   
   
       33 ) The implant of  claim 1  wherein the second end further comprises a cannulated receptor extending through the second end and configured to receive a guide wire for facilitating positioning of the implant.  
   
   
       34 ) A fracture fixation implant for fixation of a broken bone comprising a fracture site, a first and a second fragment on opposing sides of the fracture site, the second fragment comprising an end portion, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the implant comprising: 
 a first end configured to be placed in the intramedullary space of the first fragment;    a second end configured to be placed in the intramedullary space of the second fragment and configured to abut the end portion of the second fragment to enable axial loading of the implant at the second end.    
   
   
       35 ) The implant of  claim 34  further comprising a form configured to enable placement of the first end into the intramedullary space of the first fragment through an entry point on the bone and further configured to enable displacement of the implant across the fracture site to enable positioning of the second end into the intramedullary space of the second fragment.  
   
   
       36 ) The implant of  claim 34  wherein the implant further comprises a tip at the second end configured to provide support to an axial load on the implant from abutment of the tip against the end portion of the second fragment.  
   
   
       37 ) The implant of  claim 36  wherein the tip resists side-to-side displacement of the second fragment.  
   
   
       38 ) The implant of  claim 36  wherein the end portion has an endosteal surface having a contour and the tip has a contour configured to largely conform to the contour of the endosteal surface.  
   
   
       39 ) The implant of  claim 38  wherein the surface contour of the tip is large enough to spread the axial load on the implant at the second end over a large contact area.  
   
   
       40 ) The implant of  claim 36  further comprising a longitudinal receptor disposed at the tip and configured to capture a fastener to releasably mate the implant to the end portion and fix the end portion to the tip.  
   
   
       41 ) The implant of  claim 40  wherein the fastener comprises a bone screw.  
   
   
       42 ) The implant of  claim 40  further comprising a receptor for receiving a driver configured to facilitate movement of the implant within the intramedullary space wherein the longitudinal receptor and receptor configured to receive the driver are the same.  
   
   
       43 ) The implant of  claim 34  further comprising a receptor on the second end for receiving a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       44 ) The implant of  claim 43  wherein the receptor is disposed on the periphery of the second end of the implant.  
   
   
       45 ) The implant of  claim 34  further comprising at least one cross-locking receptor disposed on the second end.  
   
   
       46 ) The implant of  claim 45  in which said cross locking receptor is directed volarly.  
   
   
       47 ) The implant of  claim 46  in which the direction is approximately 17 degrees volar.  
   
   
       48 ) The implant of  claim 45  in which the cross locking receptor is directed dorsally.  
   
   
       49 ) The implant of  claim 48  in which the direction is approximately 12 degrees.  
   
   
       50 ) The implant of  claim 45  in which the cross locking receptor is angled distally.  
   
   
       51 ) The implant of  claim 45  in which the cross locking receptor is angled proximally.  
   
   
       52 ) The implant of  claim 45  wherein the cross-locking receptor is configured to capture a fastener, the fastener configured to extend through the cross-locking receptor and engage the bone of the second fragment to securely position the implant within the second fragment.  
   
   
       53 ) The implant of  claim 52  in which the cross-locking receptor is threaded and the fastener is threaded to threadably engage the cross-locking receptor.  
   
   
       54 ) The implant of  claim 45  wherein the second end has a receptor configured to receive a driver configured to facilitate insertion of the implant into the intramedullary space.  
   
   
       55 ) The implant of  claim 54  wherein the cross-locking receptor and the receptor is configured to receive the driver configured to facilitate insertion of the implant into the intramedullary space are the same.  
   
   
       56 ) The implant of  claim 45  wherein the cross-locking receptor is configured to receive a driver configured to facilitate insertion of the implant into the intramedullary space configured to facilitate longitudinal displacement of the implant within the intramedullary space.  
   
   
       57 ) The implant of  claim 34  further comprising a receptor for receiving a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       58 ) The implant of  claim 57  the receptor is disposed on the tip.  
   
   
       59 ) The implant of  claim 34  wherein the first end and the second end are formed as a single piece.  
   
   
       60 ) The implant of  claim 34  wherein the first end and the second end are formed separate pieces adjoined together to form a unitary implant.  
   
   
       61 ) The implant of  claim 60  wherein the first end comprises a tongue and the second end comprises a groove configured to receive and capture the tongue of the first end.  
   
   
       62 ) The implant of  claim 60  wherein the first end and the second end are secured together by a fastener.  
   
   
       63 ) The implant of  claim 62  wherein the fastener comprises a screw.  
   
   
       64 ) The implant of  claim 34  wherein the second end further comprises a cannulated receptor extending through the second end and configured to receive a guide wire for facilitating positioning of the implant.  
   
   
       65 ) The implant of  claim 34  wherein the bone comprises the radius and the fracture is a distal radius fracture.  
   
   
       66 ) A fracture fixation implant for fixation of a broken bone, the implant comprising a form that enables insertion of the implant in a first direction through an entry point in the bone and a form that further enables displacement of the implant in a second direction, substantially opposite to the first direction to allow bone purchase on both sides of the insertion site.  
   
   
       67 ) The implant of  claim 66  wherein the broken bone comprises a second fragment having an end portion and the implant comprises a tip configured to abut the end portion and enable axial loading of the implant at the tip.  
   
   
       68 ) The implant of  claim 67  wherein the end portion comprises an endosteal surface having a contour and the tip is contoured to largely conform to the contour of the endosteal surface.  
   
   
       69 ) The implant of  claim 67  further comprising a longitudinal receptor disposed at the tip and configured to capture a fastener to releasably mate the implant to the end portion and-fix the bone to the tip.  
   
   
       70 ) The implant of  claim 69  wherein the fastener comprises a bone screw.  
   
   
       71 ) The implant of  claim 69  further comprising a receptor for receiving a driver configured to facilitate movement of the implant within the intramedullary space wherein the receptor for longitudinal fixation and the receptor for the driver are the same.  
   
   
       72 ) The implant of  claim 66  wherein the bone comprises the radius and the fracture is a distal radius fracture.  
   
   
       73 ) The implant of  claim 66  further comprising a first and a second end, the first end configured to be positioned in the intramedullary space of a first fragment of the bone and the second fragment configured to be positioned in the intramedullary space of the second fragment of the bone.  
   
   
       74 ) The implant of  claim 67  wherein the tip resists side-to-side displacement of the second fragment.  
   
   
       75 ) The implant of  claim 68  wherein the surface contour of the tip is large enough to spread the axial load on the implant at the second end over a large contact area.  
   
   
       76 ) A fracture fixation implant for fixation of a broken bone comprising a fracture site, a first and second fragment on opposing sides of the fracture site, the second fragment having an end portion with, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the implant comprising: 
 a first end configured to be positioned in the intramedullary space of the first fragment;    a second end configured to be positioned in the intramedullary space of the second fragment, second end having a tip configured to abut the end portion of the second fragment and configured to enable axial loading of the implant at the tip; and    a form that enables insertion of the implant in a first direction through an entry point in the bone and a form that further enables displacement of the implant in a second direction, substantially opposite to the first direction to allow bone purchase on both sides of the insertion site.    
   
   
       77 ) The implant of  claim 76  wherein the end portion comprises an endosteal surface having a contour and the tip is contoured to largely conform to the contour of the endosteal surface.  
   
   
       78 ) The implant of  claim 76  further comprising a longitudinal receptor disposed at the tip and configured to capture a fastener to releasably mate the implant to the end portion and fix the bone to the tip.  
   
   
       79 ) The implant of  claim 78  wherein the fastener comprises a bone screw.  
   
   
       80 ) The implant of  claim 78  wherein the longitudinal receptor is further configured to receive a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       81 ) The implant of  claim 76  further comprising at least one cross-locking receptor disposed on the second end.  
   
   
       82 ) The implant of  claim 81  wherein the cross locking receptor is directed volarly.  
   
   
       83 ) The implant of  claim 82  wherein the direction is approximately 17 degrees volar.  
   
   
       84 ) The implant of  claim 81  wherein the cross locking receptor is directed dorsally.  
   
   
       85 ) The implant of  claim 84  wherein the direction is approximately 12 degrees.  
   
   
       86 ) The implant of  claim 81  in which said cross locking receptor is angled distally.  
   
   
       87 ) The implant of  claim 81  in which said cross locking receptor is angled proximally.  
   
   
       88 ) The implant of  claim 81  wherein the cross-locking receptor is configured to capture a fastener, the fastener configured to extend through the cross-locking receptor and engage the bone of the second fragment to securely position the implant within the second fragment.  
   
   
       89 ) The implant of  claim 88  in which the cross-locking receptor is threaded and the fastener is threaded to threadably engage the cross-locking receptor.  
   
   
       90 ) The implant of  claim 81  wherein the second end has a receptor configured to receive a driver configured to facilitate insertion of the implant into the intramedullary space.  
   
   
       91 ) The implant of  claim 90  wherein the cross-locking receptor and the receptor configured to receive the driver configured to facilitate insertion of the implant into the intramedullary space are the same.  
   
   
       92 ) The implant of  claim 76  further comprising a receptor for receiving a driver configured to facilitate movement of the implant within the intramedullary space.  
   
   
       93 ) The implant of  claim 92  wherein receptor is disposed on the tip.  
   
   
       94 ) The implant of  claim 92  wherein the receptor is disposed on the periphery of the second end of the implant.  
   
   
       95 ) The implant of  claim 76  further comprising at least one receptor disposed on a peripheral surface of the first end of the implant, the receptor configured to capture a fastener, said fastener configured to extend through the receptor and engage the bone of the proximal fragment to securely position the implant within the first fragment.  
   
   
       96 ) The implant of  claim 76  wherein the implant has largely a banana shape.  
   
   
       97 ) The implant of  claim 76  wherein the implant has a largely S shape.  
   
   
       98 ) The implant of  claim 76  wherein the entry point comprises an extended opening from the fracture site.  
   
   
       99 ) The implant of  claim 76  wherein the first end and the second end are formed as a single piece.  
   
   
       100 ) The implant of  claim 76  wherein the first end and the second end are formed separate pieces adjoined together to form a unitary implant.  
   
   
       101 ) The implant of  claim 100  wherein the first end comprises a tongue and the second end comprises a groove configured to receive and capture the tongue of the first end.  
   
   
       102 ) The implant of  claim 100  wherein the first end and the second end are secured together by a fastener.  
   
   
       103 ) The implant of  claim 102  wherein the fastener comprises a screw.  
   
   
       104 ) The implant of  claim 76  wherein the second end further comprises a cannulated receptor extending through the second end and configured to receive a guide wire for facilitating positioning of the implant.  
   
   
       105 ) The implant of  claim 76  wherein the tip is configured to resist side-to-side displacement of the second fragment.  
   
   
       106 ) The implant of  claim 77  wherein the surface contour of the tip is large enough to spread the axial load on the implant at the second end over a large contact area.  
   
   
       107 ) A method of fracture fixation for fixation of a broken bone using an intramedullary implant having a first end and a second end, the broken bone comprising a fracture site, a first and second fragment on opposing sides of the fracture site, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the method comprising: 
 forming a pathway in the intramedullary space of the second fragment to receive the second end of the implant;    inserting the implant into the intramedullary space of the first fragment through an entry point on the bone;    displacing the implant across the fracture site to position the second end of the implant in the intramedullary space of the second fragment;    adjusting the angular positioning of the implant within the second fragment;    affixing the second end to the second fragment;    reducing the fracture; and    affixing the first end to the first fragment.    
   
   
       108 ) The method of  claim 107  wherein the second fragment comprises an end portion with an endosteal surface having a contour.  
   
   
       109 ) The method of  claim 108  further comprising providing the second end of the implant with a tip comprising a contour that largely corresponds to the contour of the endosteal surface and displacing the implant across the fracture site and into the intramedullary space of the second fragment until the tip abuts the endosteal surface.  
   
   
       110 ) A method of fracture fixation for fixation of a broken bone using an intramedullary implant having a first end and a second end, the broken bone comprising a fracture site, a first and second fragment on opposing sides of the fracture site, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the method comprising: 
 inserting the implant into the intramedullary space of the first fragment through an entry point on the bone;    providing the implant with an operative surface configured to be engaged by a positioning instrument;    engaging the implant with the positioning instrument;    actuating the positioning instrument; and    displacing the second end of the implant across the fracture site and into the second fragment.    
   
   
       111 ) The method of  claim 110  wherein the operative surface comprises a serrated surface having a plurality of teeth.  
   
   
       112 ) The method of  claim 111  wherein the positioning instrument comprises a ratcheting mechanism transformable between a first, open position and second, closed position, and having a first and second tooth configured to engage the teeth of the serrated surface of the implant.  
   
   
       113 ) The method of  claim 12  further comprising the step of closing the ratcheting mechanism and displacing the second end of the implant across the fracture site and into the second end.  
   
   
       114 ) The method of  claim 110  wherein the operative surface comprises a plurality of ribs configured to be engaged by a positioning instrument.  
   
   
       115 ) The method of  claim 114  wherein the positioning instrument comprises a gear having a plurality of teeth configured to engage the ribs of the implant.  
   
   
       116 ) The method of  claim 115  further comprising the step actuating the positioning instrument, whereby said actuation causes the gear to rotate and displace the second end of the implant into the second fragment.  
   
   
       117 ) The method of  claim 110  further comprising the steps of: 
 providing the implant with at least a first track;    providing the positioning instrument with at least a first tongue configured to engage the first track on the implant; and    actuating the positioning instrument to cause the first tongue to engage the first track on the implant.    
   
   
       118 ) A method of fracture fixation for fixation of a broken bone using an intramedullary implant having a first end and a second end, the broken bone comprising a fracture site, a first and second fragment on opposing sides of the fracture site, and an intramedullary space within the bone with portions on opposing sides of the fracture site, the method comprising: 
 inserting the implant into the intramedullary space of the first fragment through the fracture site;    providing the implant with a receptor configured to receive a displacement means operatively associated with a positioning instrument for displacing the second end of the implant across the fracture site and into the second fragment;    engaging the displacement means and receptor;    actuating the positioning instrument; and    displacing the second end of the implant across the fracture site and into the second fragment.    
   
   
       119 ) The method of  claim 118  wherein the displacement means comprises flexible wire, ribbon or suture.  
   
   
       120 ) The method of  claim 118  further comprising the steps of: 
 providing the implant with at least a first track extending longitudinally on the periphery of the implant;    providing the positioning instrument with at least a first tongue configured to engage the first track on the implant; and    actuating the positioning instrument to cause the first tongue to engage the first track on the implant.