Abstract:
A device for guiding a drilling tool to form an opening in a bone, comprises a body extending from a distal end to a proximal end, the body including a lumen extending therethrough, the lumen being sized and shaped to slidably accommodate a guidewire therein and a plurality of arms extending proximally from the proximal end, the arms being disposed about the lumen with a gripping surface of each arm being spaced radially from an axis of the guide wire lumen by a distance corresponding to a thickness of a guidewire to be received therein, the gripping surfaces gripping the guidewire to maintain a portion thereof extending proximally of the lumen along the axis of the lumen.

Description:
PRIORITY CLAIM 
       [0001]    The present application claims priority to U.S. Provisional Application Ser. No. 61/150,090 filed on Feb. 5, 2009 entitled “Reamer and Drill Guiding Device,” the entire disclosure of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to devices for treating fractures and, in particular, relates to a device for guiding a drill or a reamer co-axially along a guidewire inserted into a bone such that an opening may be formed in the bone at a desired angle and position to accommodate the insertion of a fixation device therethrough. 
       BACKGROUND 
       [0003]    An intramedullary nail is a device used to stabilize long bones such as the tibia or femur. The intramedullary nail is inserted into a medullary canal of the long bone to align and stabilize the bone after an opening through the cortical bone has been formed using, for example, a drill or reamer. To ensure a proper angle of insertion for the intramedullary nail, a guidewire (e.g., a k-wire) may be used to guide the drill or reamer into the bone at the desired angle. The guidewire is generally inserted into the bone at the desired angle and position and the drill or reamer is then slid over the guidewire. To attain the desired angle and position for the cortical bone opening, the drill or reamer should be co-axial with the guidewire. However, in some cases, a bending force at one end of the drill or reamer results in the drill or reamer becoming displaced such that the opening of the cortical bone is formed at an improper angle and/or position 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is directed to a device for guiding a drilling tool to form an opening in a bone, comprising a body extending from a distal end to a proximal end, the body including a lumen extending therethrough, the lumen being sized and shaped to slidably accommodate a guidewire therein and a plurality of arms extending proximally from the proximal end, the arms being disposed about the lumen with a gripping surface of each arm being spaced radially from an axis of the guide wire lumen by a distance approximately corresponding to a thickness of a guidewire to be received therein, the gripping surfaces gripping the guidewire to maintain a portion thereof extending proximally of the lumen along the axis of the lumen. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  shows a side view of a system according to an exemplary embodiment of the present invention; 
           [0006]      FIG. 2  shows a perspective view of a device according to the system of  FIG. 1 ; 
           [0007]      FIG. 3  shows a cross-sectional side view of the device of  FIG. 2 ; 
           [0008]      FIG. 4  shows another side view of the device of  FIG. 2 , rotated about a longitudinal axis thereof with respect to  FIG. 3 ; 
           [0009]      FIG. 5  shows a perspective view of the system of  FIG. 1 , in a guiding configuration; 
           [0010]      FIG. 6  shows a cross-sectional side view of the system of  FIG. 5 ; 
           [0011]      FIG. 7  shows a perspective view of the system of  FIG. 1 , in a stopping configuration; and 
           [0012]      FIG. 8  shows a cross-sectional side view of the system of  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The present invention, which may be further understood with reference to the following description and the appended drawings, relates to devices for treating fractures. In particular, exemplary embodiments of the present invention describe a device for guiding a drill or a reamer co-axially along a guidewire inserted into a bone such that an opening may be formed in the bone at a desired angle and position to accommodate the insertion of a fixation device therethrough. It will be understood by those of skill in the art that although the exemplary embodiments are described in regard to the formation of a cortical opening for the insertion of an intramedullary nail, the device may be used for creating a bone opening in any situation in which a guidewire is used. It should also be noted that the terms “proximal” and “distal,” as used herein, are used to describe a direction toward (proximal) and away from (distal) a user of the device. 
         [0014]    As shown in  FIG. 1 , a system  100  according to an exemplary embodiment of the present invention comprises a device  102  that may be used to guide a drilling tool  104  co-axially along a guidewire  106  inserted into a bone  108  to form a cortical opening in the bone  108  at a desired angle and/or position. As shown in  FIGS. 2-4 , the device  102  comprises a body portion  110  and a plurality of arms  112 . The body portion  110  extends longitudinally from a distal end  114  to a proximal end  116  and includes a lumen  118  extending therethrough from the distal end  114  to the proximal end  116 . The lumen  118  is preferably sized and shaped to slidably accommodate the guidewire  106 . In a preferred embodiment, the body portion  110  may be substantially cylindrical. However, it will be understood by those of skill in the art that the body portion  110  may take a variety of shapes and sizes. 
         [0015]    The arms  112  extend from the proximal end  116  and are positioned around the lumen  118 . Each of the arms  112  may include a contact portion  120  protruding radially inward (i.e., toward an axis of the lumen  118 ) from a proximal end  122  of a radially inner surface  124  of the arm  112 . Each of the arms  112  may also be angled inward toward the longitudinal axis of the lumen  118  such that a distance between the contact portions  120  is substantially the same as or smaller than a diameter of the lumen  118 . This permits the contact portions  120  to hold the guidewire  106  along the axis of the lumen  118  proximally beyond the proximal end of the lumen  118 . In a preferred embodiment, the device  102  includes two arms  112 . However, it will be understood by those of skill in the art that the device  102  may include any number of arms  112  so long as the arms  112  are formed about the lumen  118  with that the contact portions  120  thereof positioned to hold a guidewire  106  received within the lumen  118  on the axis of the lumen  118 . 
         [0016]    The drilling tool  104 , as shown in  FIGS. 5-8  may be any device capable of drilling a hole in the bone  108  or reaming an existing hole in the bone  108  by sliding along the guidewire  106  such as, for example, a hollow drill. The drilling tool  104  includes a lumen  130  extending therethrough for accommodating the guidewire  106 . The lumen  130  of the drilling tool  104  includes a distal portion  132  sized and shaped to accommodate the device  102  and a proximal portion  134  extending proximally therefrom sized and shaped to accommodate the guidewire  106 . The lumen  130  includes a shoulder  136  angled radially outward at a point where the distal portion  132  and the proximal portion  134  meet such that a cross-section of the distal portion  132  distal of the shoulder  136  is larger than a cross-section of the proximal portion  134  proximal of the shoulder  136 . A distal end  140  of the drilling tool  104  includes a cutting edge sized and shaped to drill a desired cortical opening with an outer surface  138  of the drilling tool  104  sized shaped accordingly. As would be understood by those skilled in the art, the guidewire  106  may be any standard wire useful for guiding a drilling tool  104  therealong. For example, the guidewire  106  may be a Kirschner wire (k-wire). 
         [0017]    According to an exemplary method of use of the system  100 , a distal end  126  of the guidewire  106  is inserted into the bone  108  at a desired position and/or angle for the cortical opening. A proximal end  128  of the guidewire  106  is inserted through the lumen  118  at the distal end  114  of the device  102  and the device  102  is slid over the guidewire  106  until the distal end  114  comes into contact with the bone  108 . It will be understood by those of skill in the art that the contact portions  120  of the arms  112  hold the guidewire  106  firmly therebetween. Once the device  102  has been slid to the appropriate position, the proximal end  128  of the guidewire  106  is inserted into the lumen  130  of the drilling tool  104  such that the drilling tool  104  is slidable therealong, as shown in  FIGS. 5 and 6 , in a guiding configuration. In the guiding configuration, the contact portions  120  of the arms  112  hold the guidewire  106  therebetween such that, even when a bending force is exerted on a portion of the drilling tool  104 , the drilling tool  104  will not become displaced and will be guided therealong, co-axially with the guidewire  106 . Thus, the drilling tool  104  slides co-axially along the guidewire  106  until the distal portion  132  of the drilling tool  104 , reaches the bone. Thus, the device  102  acts as a guide for the drilling tool  104  until the distal end  140  reaches the bone  108 , ensuring that the cortical opening will not be displaced or improperly drilled/reamed or damaged. 
         [0018]    During the drilling of the bone, the drilling tool  104  continues to slide distally along the guidewire  106  into the bone  108  such that the device  102  enters the distal portion  132  of the drilling tool  104 , as shown in  FIGS. 7 and 8 , in a stopping configuration. As the drilling tool  104  continues to slide along the guidewire  106  and the device  102 , the drilling tool  104  continues to drill through the bone  108 . In the stopping configuration, the device  102  slides within the distal portion  132  of the lumen  130  relative to the drilling tool  104  until the device  102  comes into contact with the shoulder  136  of the lumen  130 . Thus, in the stopping configuration, the device  102  is within the distal portion  132  of the lumen  118  and acts as a stopper such that once the proximal end  136  of the distal portion  132  abuts the proximal end  122  of the arms  112  of the device  102 , the drilling tool  104  may not slide any further distally. Thus, in the stopping configuration, the device  102  stops the drilling tool  104  limiting the drilling of the cortical opening to a predetermined depth. Once the cortical opening has been drilled as desired, the drilling tool  104 , the guidewire  106  and the device  102  may simply be removed from the bone  108  such that the intramedullary nail may be inserted into the medullary canal of the bone via the cortical opening. 
         [0019]    It will be apparent to those skilled in the art that various modifications and variations may be made in the structure and methodology of the present invention, without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.