Abstract:
A keel punch impactor comprises a main body having an interior bore. A locking shaft is positioned in the interior bore of the main body, the locking shaft defining a shaft axis. An actuator is in contact with the locking shaft. The actuator is moveable between a first position and a second position. The position of the locking shaft is moved within the interior bore of the main body upon movement of the actuator. In particular, the locking shaft is moved such that the shaft axis is offset when the actuator is moved from the first position to the second position. When the shaft is moved, a head on the shaft is moved into or out of alignment with a boss extending from the main body of the keel punch impactor.

Description:
This application claims the benefit of U.S. Provisional Application Ser. No. 61/008,375, filed Dec. 20, 2007, the disclosure of which is herein incorporated by reference. 
    
    
     FIELD 
     This invention relates to the field of surgical instruments, and more particularly to a device for connecting surgical instruments used during orthopedic surgery. 
     BACKGROUND 
     Surgical procedures often involve the use of various mechanical devices that assist the surgeon in performing various tasks during the surgical procedure. Many of these surgical devices are multi-part devices that require connection (or disconnection) during the procedure. It is desirable to make the connection or disconnection of these devices as easy as possible to assist the surgeon during the surgical procedure. Of course, during surgical procedures the surgical devices are often surrounded by patient tissue or other surgical devices, leaving limited options for connection and disconnection arrangements. 
     One example of a multi-part surgical device is the keel punch used during orthopedic knee surgery. In general, the keel punch includes an impactor that is connected to a broach prior to or during surgical procedure. During a total knee replacement procedure, the impactor of the keel punch is used to drive the broach into the patient&#39;s tibia. The impactor must then be removed from the broach, leaving the broach embedded in the tibia. 
     In view of the foregoing, it would be desirable to provide an orthopedic surgical device that facilitates quick and easy connection or disconnection between two components of the surgical device. In particular, it would be advantageous to provide a keel punch impactor with a handle that could be quickly and easily attached to and/or removed from the broach of the impactor during the surgical procedure. It would also be advantageous if the handle could be easily connected to the broach with minimal interference from patient tissue and/or other surgical devices during the surgical procedure. 
     SUMMARY 
     Disclosed herein is a surgical instrument connection device. In at least one embodiment, the device comprises a main body having an interior bore. A locking shaft is positioned in the interior bore of the main body, the locking shaft defining a shaft axis. An actuator is in contact with the locking shaft. The actuator is moveable between a first position and a second position. The position of the locking shaft is moved within the interior bore of the main body upon movement of the actuator. In particular, the locking shaft is moved such that the shaft axis is offset when the actuator is moved from the first position to the second position. 
     In at least one embodiment the surgical connection device includes a boss extending from the main body and a lip or flange positioned on the end of the locking shaft. The flange is flush with the boss or contained within the footprint of the boss when the actuator is in the second position. The flange is offset from the boss or protrudes outside of the boss when the actuator is in the first position. A broach is connected to the main body by moving the actuator from the first position to the second position such that the lip is flush with the boss. The mouth of the broach is then engaged with the boss. When the actuator is returned to the first position, the lip of the locking device engages a shoulder on the broach to lock the broach to the main body. In at least one embodiment, the actuator includes a button positioned in a transverse passage provided in the main body. The transverse passage extends between an outer surface of the main body and the interior bore. 
     In at least one embodiment, the surgical instrument connection device is provided on a keel punch impactor. The keel punch impactor comprises a handle portion including an impact surface and a coupling portion connected to the handle portion. The coupling portion defines an elongated interior cavity configured to receive an elongated member. The actuator is in contact with the elongated member in the interior cavity. The actuator is moveable between a first position and a second position, wherein the position of the elongated member is shifted laterally within the elongated interior cavity when the actuator is moved from the first position to the second position. 
     In at least one embodiment, the keel punch impactor comprises a handle portion defining an impact axis. A coupling portion is connected to the handle portion, the coupling portion including an end portion with a footprint provided along the impact axis. A flange is provided at the end portion of the coupling portion. The flange is moveable between a first position and a second position. When in the second position, the flange is substantially contained within the footprint of the end portion. When in the first position, the flange protrudes outside the footprint of the end portion. 
     The above described embodiments, features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exploded isometric view of a keel punch impactor; 
         FIG. 2  shows a perspective view of the assembled keel punch impactor of  FIG. 1 ; 
         FIG. 3  shows a cutaway side view of the coupling portion of the keel punch impactor of  FIG. 1  with the shaft in a locking position; 
         FIG. 4  shows the coupling portion of  FIG. 3  with the shaft in an unlocking position; 
         FIG. 5  shows a cross-sectional view of a broach for connection to the coupling portion of  FIG. 4 ; and 
         FIG. 6  shows the broach of  FIG. 5  connected to the coupling portion of  FIG. 3 . 
     
    
    
     DESCRIPTION 
     With reference to  FIGS. 1 and 2 , a surgical instrument connection device is shown as part of an orthopedic keel punch impactor  10 . The keel punch impactor  10  generally includes a handle portion  12  connected to a coupling portion  14 . An actuator  16  is provided on the coupling portion  14  of the instrument. The keel punch impactor  10  is comprised of a relatively rigid biocompatible material, such as stainless steel. However, it will be recognized that various other materials may be used to form the keel punch impactor  10 . 
     The handle portion  12  includes a proximal end  20  and a distal end  22 . An impact plate  24  is threadedly connected to the handle  12  at the proximal end  20 . The impact plate  24  includes a flat outer surface that is designed to be struck by a hammer or other tapping device in order to force the keel punch impactor  10  in the axial direction (i.e., along impact axis  18 ). 
     The central portion of the handle  12  is designed and dimensioned to be grasped by the hand of a surgeon or other surgical team member. The handle  12  may include various contours and other features, such as finger indentations  28  to assist the user in grasping the handle. 
     A threaded bore  26  is formed in the distal end  22  of the handle  12 . The threaded bore  26  is configured to receive a threaded post  30  on the coupling portion  14 . Engagement of the post  30  with the bore  26  and subsequent rotation of the handle  12  relative to the coupling portion  14  allows the handle  12  to be secured to the coupling portion  14 . 
     The coupling portion  14  generally comprises a main body  32  that is connected to the handle  12 . The post  30  of the coupling portion  14  is provided on the proximal end  36  of the main body. As set forth above, the threaded post  30  facilitates threaded engagement of the coupling portion  14  with the handle portion  12 . 
     An enlarged collar portion  40  is provided on the main body  32 . The collar portion  40  is adjacent to an elongated neck portion  42  on the main body. The neck portion  42  extends between the collar portion  40  and a boss  46 . The boss  46  extends from the distal end  38  of the main body  32 . The shape of the outer surface of the boss  46  defines a footprint for the boss  46 . In the embodiment shown herein, the footprint is a circular footprint, however, it will be recognized that the footprint of the boss may take on various other shapes in different embodiments. As will be explained in further detail below, the boss  46  is configured to engage a broach member that fits over the boss. 
     With reference now to  FIG. 3 , the main body  32  of the coupling portion  14  includes an interior bore  34  that extends from the proximal end  36  to the distal end  38  of the main body  32 . An elongated member in the form of a locking shaft  44  is positioned in the interior bore  34  of the main body, with the locking shaft  44  extending substantially parallel to the axis  18 . One end of the locking shaft  44  extends through the boss  46  and protrudes outward from the distal end  38  of the main body  32 . An opposite end of the locking shaft  44  engages the actuator  60  provided in the collar portion  40  of the main body  32 . 
     As can be seen in  FIGS. 3 and 4 , the diameter of the interior bore  34  of the coupling portion  14  is substantially larger than the diameter of the locking shaft  44 . Accordingly, the locking shaft  44  is moveable laterally within the interior bore  34  (i.e., in a direction substantially perpendicular to the axis  18 ) between a first position and a second position. The first position of the locking shaft  44  is shown in  FIG. 3  with the locking shaft  44  closer to a first side of the interior bore  34  (in the orientation shown, the locking shaft  44  is closer to the upper side of the interior bore  34 ). The second position of the locking shaft is shown in  FIG. 4  with the locking shaft  44  closer to an opposite side of the interior bore  34  (in the orientation shown, the locking shaft  44  is closer to the lower side of the interior bore  34 ). In both the first position and the second position, the axis of the locking shaft remains substantially parallel to the impact axis  18 . 
     The locking shaft  44  includes an elongated trunk portion  48  connected to a head portion  50 . The head portion  50  provides an enlarged portion or lateral protrusion at the distal end of the locking shaft  44 . In at least one embodiment, the head portion  50  has the same general shape as the boss  46 . When the head portion  50  is aligned with the boss  46  (as shown in  FIG. 4 ), the outline of the head portion  50  substantially matches the footprint of the boss  46  or is contained within the footprint of the boss. When the head portion  50  is not aligned with the boss (as shown in  FIG. 3 ), the head provides a lip or flange that protrudes outside of the footprint of the boss. A hole  52  is provided on the end of the locking shaft  44  opposite the head portion  50  to facilitate engagement of the locking shaft with the actuator  16 . 
     The actuator  16  is in contact with the locking shaft and is operable to move the locking shaft laterally within the internal bore  34  between two positions, such as the position shown in  FIG. 3  and the position shown in  FIG. 4 . The actuator includes a pushbutton  60 , a bolt  62 , and a spring  64 . The bolt  62  passes through the hole  52  provided in the proximal end of the locking shaft  44 . The bolt is connected to the button  60  on one side of the locking shaft  44  and passes through the center of the spring  64  on the opposite side of the locking shaft. 
     The actuator  16  is positioned in a seat in the collar portion  40  of the main body. The seat is provided as a transverse passage  66  that extends completely through the coupling portion  14 , the transverse passage  66  being substantially perpendicular to the impact axis  18 . The pushbutton  60  is provided as a cylindrical member on one side of the seat. One end of the pushbutton  60  abuts the locking shaft  44  in the interior bore  34  of the main body  32 . This end of the pushbutton  60  also includes a threaded cavity that receives a threaded portion of the bolt  62 . The opposite end of the pushbutton includes an exposed surface/end  70  that protrudes outward from the collar portion  40  of the main body  32 . 
     The spring  64  is positioned on the opposite side of the transverse passage  66  from the pushbutton  60 . The spring  64  is trapped between a shoulder  68  in the transverse passage  66  and the locking shaft  44 . The bolt  62  extends through the spring  64  and the locking shaft  44  and connects to the pushbutton  60  on the opposite side of the locking shaft from the spring. 
     In operation, the actuator is configured to move between a first position and a second position. The first position is shown in  FIG. 3 . In this position, no force is being applied to the exposed end  70  of the pushbutton  60 . Accordingly, the spring  64  acts against the shoulder  68  and force the locking shaft  44  to the upper side of the interior bore  34 . With the locking shaft  44  in this position, the exposed end  70  of the pushbutton  60  is forced its outermost position away from the main body of the coupling member  14 . Also, when the locking shaft  44  is in this position, the head  50  is misaligned with the boss  46 , with a lip on the head  50  provided outside of the footprint of the boss  46 , as shown in  FIG. 3 . 
     The second position of the actuator is shown in  FIG. 4 . In this position, a user is applying a force to the pushbutton  60  in the direction of arrow  72 . The force applied by the user forces the pushbutton  60  further into the transverse passage  66 . As the pushbutton  60  is forced further into the transverse passage  66 , the pushbutton  60  forces the locking shaft  44  against the opposite side of the interior bore  34  (i.e., the lower side of the interior bore in the orientation of  FIG. 4 ). This also causes the spring to be compressed in the transverse passage between the locking shaft  44  and the shoulder  68 . With the locking shaft  44  in this position in the interior bore  34 , the head  50  of the locking shaft  44  is aligned with the footprint of the boss  46 , as shown in  FIG. 4 . 
     When the user removes the force against the pushbutton  60 , the compressed spring  64  once again acts against the locking shaft  44 , forcing it toward the opposite side of the interior bore (i.e., the upper side of the interior bore as shown in  FIG. 3 ). This action also causes the head  50  of the locking shaft  44  to be misaligned with the boss  46  and forces the pushbutton  60  further out of the transverse passage  66 . Accordingly, although the actuator is moveable between a first position (e.g.,  FIG. 3 ) and a second position (e.g.,  FIG. 4 ), it is biased toward the first position. 
     With reference now to  FIG. 5 , a broach  80  is shown configured for connection to the coupling portion  14  of the keel punch impactor  10 . The broach  80  is generally a pointed instrument configured to be driven into the bone, such as a keel configured to be driven into the medullary canal of the tibia. It will be recognized that the broach  80  of  FIG. 5  is merely exemplary and broaches of various configurations, sizes and shapes may be used with the keel punch impactor  10  disclosed herein. 
     The broach  80  of  FIG. 5  includes a distal tip  82  on one end and a mouth  84  on the opposite end. The mouth  84  of the broach  80  is designed to fit over the boss  46  protruding from the main body  32  of the coupling portion  14 . An interior groove  86  is formed within the mouth  84 . The groove is defined by an interior shoulder  88  configured to engage the edge of the head  50 . 
     In order to connect the broach  80  to the impactor  10 , the user first presses the pushbutton  60 , forcing the locking shaft  44  against one side of the interior bore  34 , as shown in  FIG. 4 . In this position, the head  50  of the locking shaft  44  is aligned with the boss  46 . Next, the head  50  and boss  46  are inserted into the mouth  84  of the broach  80  along the impact axis  18 . The user then releases the pushbutton  80 , causing the spring to force the locking shaft  44  to the opposite side of the interior bore  34 , as shown in  FIG. 3 . When the locking shaft moves to the opposite side of the interior bore, the head  50  on the locking shaft  44  becomes misaligned with the boss  46 , and the edge of the head  50  moves into the groove  86  on the broach. When the edge of the head  50  moves into the groove  86 , the head  50  abuts the shoulder  88  on the broach, as shown in  FIG. 6 . With this relationship, the broach  80  is locked in place on the coupling portion  14  in the direction of axis  18 . 
     To release the broach  80  from the coupling portion  14 , the user simply presses the pushbutton  60  inward, thus causing the head  50  to be removed from the shoulder  88  of the broach  80  and aligned with the boss  46  on the coupling portion  14 . The broach  80  may then be removed from the coupling portion  14  by removing the mouth  84  of the broach  80  from the boss  44  in the direction of impact axis  18 . 
     Although the present invention has been described with respect to certain preferred embodiments, it will be appreciated by those of skill in the art that other implementations and adaptations are possible. For example, although the structure of the actuator has been described as a bolt passing sequentially through the spring, the locking shaft, and into the pushbutton, the actuator could also be configured such that the bolt passes sequentially through the pushbutton and the spring and then passes into the locking shaft. This is but one example of an alternative embodiment, and it will be recognized that the elements described herein may take on different shapes and forms than those described herein. Those of skill in the art will also recognize that various components and features described herein, including the handle portion, the coupling portion, the actuator, the broach, or any other component, could be implemented differently than that described herein. Moreover, there are advantages to individual advancements described herein that may be obtained without incorporating other aspects described above. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments contained herein.