Patent Publication Number: US-7588537-B2

Title: Connector with safety latch for a surgical retractor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of application Ser. No. 11/219,847 filed Sep. 7, 2005. 

   BACKGROUND 
   Surgical procedures often require the creation of a surgical exposure to allow a surgeon to reach deeper regions of the body. The surgical exposure is usually started with an incision of a suitable depth. Surgical instruments known as retractors are then inserted into the incision and used to pull back skin, muscle and other soft tissue to permit access to the desired area. 
   A typical retractor is made up of a retractor body attached to one or more retractor blades. Retractor blades are smooth, thin plates with dull edges that are inserted into the incision to pull back the tissue. Retractor blades come in many different sizes depending on the particular application and physical characteristics of the patient. Retractor blades may be slightly curved or completely flat and may have end prongs of various configurations to make it easier to pull back tissue. The retractor blades can be attached to a wide variety of retractor bodies, such as for hand-held and self-retaining retractors. 
   Hand-held retractors are made up of a simple grip attached to a retractor blade. The retractor blade may be fixed or interchangeable. The retractor blade is inserted into the incision and then the grip is used to pull back the blade to create the surgical exposure. The grip may be attached at an angle to the retractor blade to make it easier to pull back on the blade. Hand-held retractors must be held in place by hand in order to maintain the surgical exposure. 
   Self-retaining retractors have specialized retractor bodies that allow them to maintain a surgical exposure without needing to be held in place by hand. Two common self-retaining retractors are longitudinal retractors and transverse retractors. 
   Longitudinal retractors have a retractor body made up of two seesawing arms with a pair of opposed retractor blades on their respective ends. The retractor body typically has a ratcheting mechanism to lock apart the two opposed retractor blades and hold them in place. This maintains the surgical exposure without the need for the retractor to be held in place by hand. The two arms may be hinged to facilitate access to the retraction site. The retractor blades may be either fixed or interchangeable. 
   Transverse retractors have a retractor body made up of a transverse rack with a fixed arm and a sliding arm. The fixed arm and sliding arm have opposed retractor blades on their respective ends. The sliding arm typically has a turnkey that operates a ratcheting mechanism, which ratchets the sliding arm away from the fixed arm and locks apart the retractor blades. The two arms may be hinged to facilitate access to the retraction site. The retractor blades may be either fixed or interchangeable. 
   For interchangeable retractor blades, there are several connector designs for allowing the retractor blades to be interchangeably attached to the retractor body. One connector is the top-loading ball snap design, which resembles the mechanism found in common ball-and-socket wrench kits. 
   The ball snap design uses a top-loading socket which fits over the top of the ball snap. The retractor blades used with the ball snap design typically have a top end bent at a right angle to create a perpendicular section on which the ball snap is mounted. 
   The ball snap design allows the retractor blades to positively lock into the top-loading socket. This allows the entire retractor to be assembled and handed to the surgeon without the risk of the retractor blades falling off. It also permits the entire retractor to be repositioned in the incision without the risk of the retractor blades becoming detached from the retractor body. 
   However, many surgeons prefer to position the retractor blades first before attaching the retractor body. Positioning the retractor blades first makes it much easier for the surgeon to create a precise surgical exposure before attaching the retractor body. Pre-positioning of the retractor blades also facilitates the selection of the proper retractor blade length and width. 
   With the ball snap design, the surgeon must line up the sockets in the retractor body over the tops of the ball snaps before snapping the retractor blades in place. This is a difficult process, as the retractor body arms must be aligned over the ball snaps precisely in order to attach the retractor blades. This alignment process is complicated by the hinged arms and ratcheting mechanisms often found in retractor bodies. 
   Current side-loading designs attempt to address these problems by making it easier to load the retractor blades into the retractor body after the surgeon has pre-positioned the retractor blades. Current side-loading designs use a post or rail that allow the retractor blades to be loaded from the side. This allows the retractor body to be placed between the retractor blades and then simply opened up to engage the retractor blades from the side. 
   However, current side-loading designs do not allow the retractor blades to be positively locked into the retractor body. This means the entire retractor cannot be assembled and then handed to a surgeon without the risk of the retractor blades falling off. The retractor blades are held in place only by the opposing force of the retracted tissue and may become detached from the retractor body if the surgeon tries to reposition the retractor blades inside the incision. Furthermore, current side-loading designs often misalign, resulting in a poor connection between the retractor blade and the retractor body. 
   What is needed is a surgical retractor with interchangeable retractor blades, where the retractor body can accept the retractor blades easily without the need for precise alignment and where the retractor blades can be positively locked into the retractor body. 
   SUMMARY 
   According to an embodiment, a connector includes a body member having an opening for receiving a nipple of a retractor blade. The connector also includes a retainer pivotally attached to the body member between an open position and a closed position. A lock mechanism locks the retainer in the closed position so that the nipple of the retractor blade is locked in the connector. A safety latch constrains the lock mechanism when the retainer is in the closed position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Examples of the invention are illustrated, without limitation, in the accompanying figures in which like numeral references refer to like elements and wherein: 
       FIGS. 1A ,  1 B and  1 C show perspective diagrams of a surgical retractor blade for use with a connector in with an embodiment of the invention; 
       FIGS. 2A ,  2 B, and  2 C show perspective and cut away diagrams of a connector in accordance with an embodiment of the invention; 
       FIGS. 3A and 3B  show perspective and cut away diagrams of a connector in accordance with another embodiment of the invention; 
       FIGS. 4A and 4B  show perspective diagrams of a connector in accordance with another embodiment of the invention; 
       FIG. 5  shows a perspective view of a surgical retractor including connectors in accordance with an embodiment of the invention; 
       FIGS. 6A and 6B  show perspective diagrams of a connector in accordance with another embodiment of the invention; and 
       FIG. 7  shows a perspective view of a surgical retractor including connectors in accordance with another embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   For simplicity and illustrative purposes, the principles are shown by way of examples of systems and methods described. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the examples. It will be apparent however, to one of ordinary skill in the art, that the examples may be practiced without limitation to these specific details. In other instances, well known methods and structures are not described in detail so as not to unnecessarily obscure understanding of the examples. 
   In an example, a connector for a surgical retractor includes a body member, a retainer and a lock mechanism. The body member includes an opening for receiving a nipple of a retractor blade. The retainer is pivotally attached to the body member between an open position and a closed position. The nipple of the retractor blade, when placed into the opening of the body member, engages a mating portion of the retainer and causes the retainer to pivot from the open position to the closed position. The lock mechanism maintains the retainer in the closed position when the nipple is fully inserted into the opening of the body member. Once fully inserted, the nipple may only be removed by disengaging the locking mechanism. In one example, the connector includes a spring to bias the retainer in an open position. In this case, when disengaging the locking mechanism, the retainer ejects, or helps to eject, the nipple from the opening of the body member. 
   In one example, the opening of the connector is approximately semi-annular in shape and adapted to receive a generally cylindrical nipple. Correspondingly, the mating portion of the retainer is semi-annular and cylindrical. The opening may also include a ridge for aligning with an annular trench located around the periphery of the nipple. 
   In another example, the opening of the connector is approximately semi-annular in shape and adapted to receive a tapered nipple. Correspondingly, the mating portion of the retainer is semi-annular and tapered. The opening may also include a ridge for aligning with an annular trench located around the periphery of the nipple. 
   In yet another example, the lock mechanism may include a push button having a base and a shoulder. The base of the push button may reside or partially reside within the retainer while the shoulder is spring biased towards the body member. As the retainer pivots, the shoulder of the push button rides along a slot until the retainer is fully closed. At that point, the shoulder of the push button engages, or pushes into, a recessed notch within the body member. This positively locks the retainer in the closed position until a user disengages the locking mechanism by pushing the push button. 
   In yet another example, the lock mechanism may include a pawl pivotally attached to the body member between a release position and a lock position. A distal end of the retainer is shaped to mate with the pawl such that the pawl retains the retainer in the closed position. The pawl is spring biased into a lock position but remains in a release position until the retainer is in the closed position. 
   With reference first to  FIGS. 1A ,  1 B and  1 C, there is shown a surgical retractor blade  100  including a nipple  102 . The nipple  102  is generally cylindrical, with a top surface  104  and a side surface  106 . The top surface  104  may have rounded edges to facilitate loading of the retractor blade  100 . The side surface  106  may contain a groove  108 . The groove  108  may be circumferential around the nipple  102 . The nipple  102  may also have a fixing pin  110 . 
   The retractor blade  100  may be rectangular or trapezoidal in shape and may be flat or curved. The retractor blade  100  may also be configured at a right angle rear a proximal end  112  wherein the nipple  102  is attached. The retractor blade  100  has a distal end  114  that may be angled to allow it to reach around and pull back soft tissue. The retractor blade  100  may also contain one or more prongs  116  at its distal end. The prongs  116  may be of different shapes and sizes depending on the application. 
   The retractor blade  100  may be constructed of plastic, ceramic, aluminum, stainless steel or titanium. A set of retractor blades may also be color-coded with an anodized finish for quick selection of the desired size and length. 
     FIG. 2A  shows a perspective view of a connector  200  for a surgical retractor (shown in  FIG. 5 ). The connector  200  includes a body member  202 , a retainer  204 , a lock mechanism  206  and a spring  208 . The body member  202  includes an opening  210  for receiving a nipple of a retractor blade such as the one described in  FIG. 1 . However, the opening  210  may be adapted to receive various types of retractor blades having various types of nipples or connector heads. The retainer  204  is pivotally mounted to the body member  202  at a pivot point and pivots between an open position and a closed position.  FIG. 2A  shows the retainer  204  in the closed position. The spring  208  biases the retainer  204  in the open position. The biasing provides a force which allows the retainer  204  to eject the nipple from the opening  210  of the body member  202 . 
   The opening  210  of the body member  202  is approximately semi-annular in shape and adapted to receive a generally cylindrical nipple. Correspondingly, a mating portion  214  of the retainer is semi-annular and cylindrical. The opening  202  may also include a ridge  216  (shown in  FIG. 2B ) for aligning with an annular trench located around the periphery of the nipple. 
     FIG. 2B  shows a cut away diagram of the connector  200  of  FIG. 2A . As shown in  FIG. 2B , the locking mechanism  206  includes a push button  218 , a post  220 , a shoulder  222 , a base  224  and a spring  226 . The body member  202  includes a slot  228  and a recessed notch  230 . The base  224  and spring  226  are partially mounted in the retainer  204 . The spring  226  biases the shoulder  222  against a surface of the body member  202  while the post  220  lies in the slot  228 . When the retainer  204  is in the closed position, the shoulder  222  slides into the recess  230  and locks the retainer  204  in the closed position. Pushing the push button  218  moves the shoulder  222  out of the recess  230  and allows the retainer  204  to move to the open position.  FIG. 2B  also illustrates a notch  232  for mating with a fixing pin of the nipple in order to prevent axial rotation of the retractor blade. 
     FIG. 2C  shows another cut away diagram of the connector  200  of  FIG. 2A . As shown in  FIG. 2C , the retractor  204  is in the closed position. The spring  226  has forced the shoulder  222  of the locking mechanism  206  into the notch  230 . When a user pushes the push button  218  and overcomes the force of the spring  226 , the shoulder  222  leaves the notch  230  and the post  220  is able to slide along the slot  228  thus allowing the retainer  204  to move from the closed position to the open position. The spring  208  applies force to the retainer  204  ejecting the nipple from the opening  210  of the body member  202 . 
     FIG. 3A  shows a perspective view of a connector  300  for a surgical retractor (shown in  FIG. 5 ). The connector  300  includes a body member  302 , a retainer  304 , a lock mechanism  306 . Also shown in  FIG. 3A  is a retractor blade  308  having a tapered nipple  310 . The body member  302  includes an opening  312  for receiving the nipple  310  of the retractor blade  308 . The retainer  304  is pivotally mounted to the body member  302  at a pivot point and pivots between an open position and a closed position.  FIG. 3A  shows the retainer  304  in the open position. 
   The opening  312  of the body member  302  is approximately semi-annular in shape and adapted to receive the tapered nipple  310 . Correspondingly, a mating portion  314  of the retainer is semi-annular and tapered. 
     FIG. 3B  shows a cut away diagram of the connector  300  of  FIG. 3A  with the retainer  304  in the closed position retaining the nipple  310  therein. As shown in  FIG. 3B , the locking mechanism  306  includes a push button  318 , a post  320 , a shoulder  322 , a base  324  and a spring  326 . The body member  302  includes a slot  328  and a recessed notch  330 . The base  324  and spring  326  are partially mounted in the retainer  304 . The spring  326  biases the shoulder  322  against a surface of the body member  302  while the post  320  lies in the slot  328 . When the retainer  304  is in the closed position, the shoulder  322  slides into the recess  330  and locks the retainer  304  in the closed position. Pushing the push button  318  moves the shoulder  322  out of the recess  330  and allows the retainer  304  to move to the open position illustrated in  FIG. 3A . 
     FIG. 4A  shows a perspective view of a connector  400  for a surgical retractor (shown in  FIG. 5 ). The connector  400  includes a body member  402 , a retainer  404  and a lock mechanism  406 . Also shown in  FIG. 4A  is a nipple  408  for a retractor blade. The body member  402  includes an opening  410  for receiving the nipple  408  of the retractor blade. The retainer  404  is pivotally mounted to the body member  402  at a pivot point and pivots between an open position and a closed position. A spring  426  biases the retainer  404  in the open position. The distal end  412  of the retainer  404  is in contact with a surface  414  of the locking mechanism (or pawl)  406  while the retainer  404  is in the open position. The pawl (or locking mechanism)  406  is pivotally mounted to the body member  402  between a release position and a lock position. A spring  420  biases the pawl  406  in the lock position. While the retainer  404  is in the open position, the surface  414  of the pawl is in contact with the distal end  412  of the retainer  404 . 
     FIG. 4B  shows a perspective view of the connector  400  of  FIG. 4A  with the retainer  404  in the closed position retaining the nipple  408  therein. The spring  420  biases and holds the pawl  406  in the lock position. The distal end  412  of the retainer  406  contacts a surface  416  and is prevented from moving to the open position by a ridge  418 . The pawl  406  therefore maintains the retainer  406  in the closed position. If a handle  422  of the pawl  406  is pushed, pivoting the pawl  406  to the release position, the ridge  418  moves away from the distal end  412  of the retainer  404  and allows the retainer  404  to move to the open position from the force of the spring  426 . 
   As with the previously described embodiments, the opening  410  of the body member  402  may be approximately semi-annular in shape and adapted to receive a generally cylindrical nipple. Correspondingly, a mating portion  424  of the retainer may be semi-annular and cylindrical. Alternatively, the opening  410  of the body member  402  may be approximately semi-annular in shape and adapted to receive a tapered nipple. Correspondingly, a mating portion  424  of the retainer is semi-annular and tapered. Although the opening  410  is illustrated as cylindrical or tapered, the opening  410  may have any shape adapted to receive various types of retractor blades having various types of nipples or connector heads. 
     FIG. 5  shows a perspective view of a surgical retractor assembly  500 . The assembly  500  includes a surgical retractor  502 , two connectors  504  and two retractor blades  506 . The retractor blades  506  include nipples  508  which are retained within the connectors  504  as shown in the embodiments described above. 
     FIGS. 6A and 6B  show perspective views of a connector  600  for a surgical retractor (shown in  FIG. 7 ). The connector  600  includes a body member  602 , a retainer  604 , a lock mechanism  606  and a safety latch  608 . The body member  602  includes an opening  610  for receiving a nipple of a retractor blade such as the one described in  FIG. 1 . However, the opening  610  may be adapted to receive various types of retractor blades having various types of nipples or connector heads. Additionally, the connector  600  is a front loading connecting with the opening  610  located in front of the connector  600  rather than on the side of the connector which is shown in  FIGS. 2 and 3 . The retainer  604  is pivotally mounted to the body member  602  at a pivot point and pivots between an open position and a closed position. 
   The connector  600  includes the safety latch  608  which is pivotally mounted to the body member  602 . The safety latch  608  includes a grip  610  and a shoulder  612 . The grip  610  provides a user with a surface to apply force thus pivoting the safety latch  608 . The shoulder  612  engages the lock mechanism  606  between a space and the body  602 . This engagement reduces the risk that the user accidentally pushes opens the lock mechanism  606  during use. Once the user attaches a blade to the connector  600 , the spring loaded safety latch  608  pivots into place. As shown in  FIG. 6A , the locking mechanism  606  is now constrained into position and will not release until the user pivots the safety latch  608  out of position and presses the lock mechanism. The user may apply force to the grip  610  thus pivoting the safety latch  608  from under the lock mechanism  606 . Once out of the way, the user may press the lock mechanism  606  to open the retainer  604  as shown in  FIG. 6B . 
     FIG. 7  shows a perspective view of a surgical retractor assembly  700  including front loading connectors as shown in  FIG. 6 . The assembly  700  includes a surgical retractor arm  602  connected to a second “L” shaped surgical retractor arm  704 . The assembly  700  may include a plurality of blades  706  having nipples  708  retained in connectors  710 . 
   What has been described and illustrated herein are examples of the systems and methods described herein along with some of their variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of these examples, which are intended to be defined by the following claims and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated.