Abstract:
A surgical appliance includes a pair of opposed prongs slideably disposed on an elongated locking track for retracting neurovascular and musculotendinous anatomical structures through an incision for affording access to deeper structures for inserting osteosynthesis hardware in the surgical treatment of a distal radius fracture or other surgical procedure. The prongs extend from retractors that traverse the locking track for opposed linear movement while recessed in a surgical working region accessible through an incision. The prongs terminate in curvatures defining a void that gather and engage the elongated anatomical structures on top of the skeletal members receiving the plate. The prongs draw back the tendons, blood vessels and nerve structures to allow unimpeded surgical access for manipulating and attaching skeletal and soft tissue members and/or appliances. The device retracts anatomical structures along a linear track for a fixed locking engagement maintaining a surgical gap without direct manual assistance.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/324,595 filed Apr. 29, 2016, entitled “TISSUE RETRACTOR FOR RADIUS FRACTURES,” incorporated herein by reference in entirety. 
     
    
     BACKGROUND 
       [0002]    A distal radius fracture is one of the more common hand and wrist surgeries performed. Treatment often requires attachment of a surgical implant to bone structures for adding strength. The surgical procedure for addressing this type of fracture can be complicated due to the number and proximity of adjacent structures, such as muscles, ligaments, tendons, and blood vessels that surround this area. The corresponding procedure requires that the tissues and muscles in the wrist be moved so that the bone can be exposed. Various surgical retraction tools are available to manipulate tissues and anatomical structures during surgery. Conventional retractors include manual articulated or rigid elongation members for positioning the adjacent anatomy by manual operation by a surgeon or assistant. 
       SUMMARY 
       [0003]    A surgical appliance includes a pair of opposed prongs slideably disposed on an elongated locking track for retracting neurovascular and musculotendinous anatomical structures through an incision for affording access to a skeletal structure for attaching a plate or support member in treatment of a distal radius fracture surgery or other surgical procedure. The prongs extend from retractors that traverse the locking track for opposed linear movement while recessed in a surgical working region accessible through the incision. The prongs terminate in curvatures defining a void that gather and engage the elongated anatomical structures on above the skeletal members receiving the plate. The prongs draw back the tendons, blood vessels and nerve structures to allow unimpeded access for attaching the plate to a bone element. 
         [0004]    Configurations herein are based, in part, on the observation that surgical procedures often employ tools for disposing, securing and maintaining anatomical structures in particular positions to permit surgical access. Such tools, or retractors, may often take the form of a scissors arrangement of pivoting members, or a single elongated member for applying leveraged force. Unfortunately, conventional approaches to surgical tool design suffer from the shortcoming that conventional surgical retraction devices often require active operation by a surgeon or assistant to physically dispose the retractor at the surgical site and maintain a retracted position. While some conventional devices have ratcheting mechanisms for maintaining an “open” position, these devices often travel in an arcuate path, tending to slip out or disengage from misaligned opposed forces. Further, a ratcheting closure affords movement only in increments defined by a granularity or spacing of the ratchet teeth. Accordingly, configurations disclosed herein substantially overcome the above-described shortcoming of conventional surgical tools by providing a locking, linear based retraction device for fixing an extremity in a pronate position while retracting tendons, vessels and nerves alongside a bone or skeletal member for implanting a plate or skeletal support device. 
         [0005]    In operation, the method of retracting anatomical structures from a surgical working region (also called “surgical field”) using the disclosed surgical retraction device for retracting tissue includes disposing a prong of a first retractor into an incision, in which the retractor is slideably attached to an elongated track. The retractor is also opposed to a second retractor on the elongated track, and a prong of the second retractor is disposed against an opposed side of the incision from the first retractor. Upon insertion, a curvature at a distal end of each prong inserted in the incision engages elongated anatomical structures such as tendons, flood vessels and nerves that lie between the incision and a skeletal member upon which a surgical plate is to be attached. The first and second retractors are disposed in opposed linear directions on the elongated track for drawing the elongated anatomical structures to opposed sides to define a gap for providing surgical access to the skeletal member, and a track lock secures the first and second retractors in the opposed positions defining the gap. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
           [0007]      FIG. 1  is a perspective view of the surgical retraction device for use as disclosed herein; 
           [0008]      FIG. 2  is a side elevation of the retraction device as in  FIG. 1 ; 
           [0009]      FIG. 3  is a disassembled view of the retraction device as in  FIG. 1 ; 
           [0010]      FIG. 4  shows the retraction device of  FIG. 1-3  installed in a surgical field; and 
           [0011]      FIG. 5  shows a side cutaway view of anatomical structures retracted by the device of  FIG. 1  in the surgical field. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Configurations below depict an example implementation of the surgical retraction tool employed for implantation of a plate on the radius for repair of a distal radius fracture involving the wrist of a patient. Alternative uses include use of the surgical retraction tool on other extremities and surgical regions for retraction along a linear track for a fixed locking engagement and maintaining a surgical field without direct manual assistance. 
         [0013]    Distal radius fractures are one of the more common fractures seen by hand surgeons. The standard surgical approach to the distal radius is the volar approach which involves making an incision on the volar aspect (the palm side) of the forearm at the wrist level. This allows for a safe and extensile exposure of the fractured aspect of the distal radius, allowing for reduction of the fracture and placement of hardware to retain the fracture in its correct or reduced position. Most commonly this involves using a plate and screws. The challenge here is that there are numerous structures that run longitudinally down the arm into the hand, and traverse the surgical field. These need to be retracted and protected in order for the procedure to be performed safely and efficiently. There are two types of surgical retractors: handheld devices which require surgeon or assistant to hold in one hand, and self-retaining retractors which do not need to be held in position manually, once they are inserted into the wound. The currently available self-retaining retractors have numerous shortcomings, hence the novel design described herein. 
         [0014]      FIG. 1  is a perspective view of the surgical retraction device for use as disclosed herein. Referring to  FIG. 1 , the tissue retraction device  100  is operable for retracting tissue over a surgical field defined by an incision in an extremity such as an arm or leg. The retraction device  100  includes an elongated track  110  and opposed, self-retaining retractors  120 - 1 ,  120 - 2  ( 120  generally) disposed on the track  110 , such that at least one of the retractors slideably engages the track  110  for linear positioning along the track  110 . Alternatively, both retractors  120  may be moveable, but generally the relative distance between the retractors  120  can be effectively altered by disposing either. Each retractor  120  includes a curvature  122  adapted to engage elongated anatomical structures on opposed sides of the surgical field, and a track lock  112  on the retractor  120  for selectively securing the retractor  120  to the track  110 . The track lock  112  is selectively engageable by a spring-loaded lever or button for disposing the retractors  120  in an opposed linear arrangement on the track  110 . 
         [0015]    In a particular arrangement as depicted, the retractors  120  comprise a radiolucent material adapted for transparency of scanning electromagnetic radiation. The radiolucency of the material allows imaging technology, such as MRI, CT scans, x-ray and other imaging technology to “scan through” the retractors such that the retractors will not appear or interfere with such imaging. Generally, such imaging expects denser tissue structures to reflect, refract, or otherwise augment a directed waveform received by an imaging sensor. The radiolucent construction permits electromagnetic and other imaging radiation to pass through the retractors and allows such scans to be free of interference of retractor images. 
         [0016]    In operation, a surgeon disposes the track  110  on the patient&#39;s extremity behind the surgical field (on the opposite side of the extremity). In a preferred arrangement, with an upwards facing incision, the track would be beneath the arm or other extremity, thus wrapping around the extremity to be operated on. After engaging the retractors on opposite sides of an incision, the retractors  120  are drawn apart to engage anatomical structures and draw them to respective sides of the incision, leaving a gap in the surgical field for access to the radius or other structure. 
         [0017]    In general, the track  110  is intended to support the retractors  120  well away and distal from the surgical field. For an extremity such as an arm or leg, this would be the opposed, or back of the extremity opposed from the incision. In a tabletop orientation, the track would be disposed along the back or bottom of an extremity with an upward facing incision. In general, the track  110  and retractors  120  form a “wrap around” position that exposes the surgical field in an opening between the retractors  120 . The track occupies a “back” or opposed region away from the surgical field, and the retractors  120  would occupy flanking or side positions of the retractors  120  around an anatomical area in which the incision is made. Such positioning allows the device, after complete assembly, and in its final resting position, to wrap around the extremity, in effect coming into the surgical field from behind, considering that the surgical field is represents the front of the extremity. The surgical field may be located anywhere on the extremity: medial, lateral, anterior, posterior or a combination of the aforementioned. 
         [0018]    The track lock  112  secures the retractor  120  to the track  110  by a biased tension that secures the retractor  120  to the track  110  in a rest position and permits slideable movement responsive to a disengaging force for removing the biased tension. The retractor  120  therefore is locked to the track  110  while in an unattended, hands-free state such that an assistant does not need to crowd the surgical field to tend to or actively hold the device to maintain tissue retraction. Upon engagement, the track lock  112  is disengaged, the retractors  120  separated a suitable distance, and the track lock  110  released to engage the lock and fix the retractor  120  to the track. As indicated above, both retractors may have a lock, but a single lock on either retractor will suffice for separating the retractors  120 . 
         [0019]    The retractors  120  have a serration  124  at a distal end of the curvature  122 . The serration  124  is adapted to engage a resilient tissue such as muscle in the surgical field, in which the curvature  122  is disposed adjacent the serration  124  for gathering abrasion sensitive anatomical structures away from the serration  124 . The serration  124  is positioned to engage muscle tissue immediately above the bone, in the case of a distal radius procedure. The muscle tissue is sufficiently resistant to abrasion and puncture such that the serrations will not injure the muscle. The curvature  122 , in contrast, is positioned to embrace more sensitive vascular and nerve structures above the muscle, discussed further below in  FIG. 5 . 
         [0020]      FIG. 2  is a side elevation of the retraction device as in  FIG. 1 . Referring to  FIGS. 1 and 2 , the device further includes a base  130 , such that each retractor  120  is secured to a base  130 - 1 ,  130 - 2  ( 130  generally). Each the bases  130  is adapted to engage a horizontal planer surface such as a operating table or table extension for maintaining an upward facing orientation of the incision and working surgical field. Just above the base is a shield  130 , which may be employed above the track lock  110  to avoid accidental disengagement. 
         [0021]      FIG. 3  is a disassembled view of the retraction device as in  FIG. 1 . Referring to  FIGS. 1-3 , each of the retractors  120  further includes a post  140 , a transverse  142 , and a prong  144 . The base  130  further comprises a tower  132  having a recess  134  adapted to receive the post  140 , and a depth  136  for defining an insertion distance, such that the post  140  is operable for engagement with the respective tower  132  for defining a distance from the base  130  to the transverse  142  for varying an insertion depth of the prong into the surgical field. The post  140  therefore extends into a tower  134  attached to the base  130  for setting a depth  136  of insertion of the prong  144  into the incision. Generally, the end of the prong  144  is such that the serration  124  engages muscle tissue just above the bone (radius). 
         [0022]    Continuing to refer to  FIGS. 1-3 , the transverse  142  extends substantially perpendicularly from the post  140  and is adapted to extend in a direction over the surgical field. The prong  144  is substantially perpendicular to the transverse  142  and parallel to the post  140 , such that the prong is adapted to extend into the surgical field beyond imposing surgical structures. Upon insertion, each opposed transverse  142  from the respective retractors  120  will almost meet, as the prongs are inserted into the incision to begin drawing the incision apart. The curvature  122  is formed at a distal end of the prong  144  and defines a void  148  for gathering elongated anatomical structures, such as blood vessels, nerves, connective tissue, and any other neurovascular and musculotendinous structures otherwise obscuring the installation of the surgical plate. 
         [0023]    As indicated above, during device installation after forming the incision, a fixed retractor  120  and a sliding retractor  120  are positioned, such that the fixed retractor is secured at an end of the track  110 , and the sliding retractor has the track lock  112  for slideably disposing the retractor  120  and varying a total distance between the retractors based on liner movement along the track  110 . The track lock  110  may frictionally engage the base  130  to the elongated track  110  by biasing a frictional body against the track under the spring load of the track lock  112 . Alternative, any suitable fixation such as a ratchet, dimple, rolling gear and tooth arrangement may suffice. 
         [0024]      FIG. 4  shows the retraction device of  FIG. 1-3  installed in a surgical field  160 . Referring to  FIG. 4 , the elongated track  110  is adapted to be disposed on a distal side of an extremity  152  opposed from the incision  154  defining the surgical field  160  defined by retracted anatomical structures  150 .  FIG. 4  shows that the base  130  is adapted to secure the retractors  120  for maintaining a pronate position of a surgical extremity  152  defining the surgical field  160 , such that the pronate position disposes the incision  154  in an upward facing manner on a horizontal surface  158 . While a pronate position may be preferred by many surgeons, the surgical device  100  could also be disposed around other suitable extremities or anatomical regions. Since the biasing force of the retracted anatomical structures fixes the surgical device  100  in the locked, open position, surgical incisions  154  on other anatomical regions may be performed, and the bases either omitted or allowed other orientation. 
         [0025]      FIG. 5  shows a side cutaway view of anatomical structures retracted by the device of  FIG. 1  in the surgical field  160 . In the surgical field  160 , the opposed retractors  120  define a gap  162 . The resulting gap  162  is closeable and expandable by disposing the retractors  120  in a linear manner along the track  110 , such that the surgical field  160  increasingly accessible with an expanding gap  162 . The gap  162  is formed from gathering and retraction of anatomical structures in the void  148  defined by the curvature  122 . Neurovascular and musculotendinous structures are concentrated above the radius  180  and ulna  182  in the surgical field  160 , and include the radial nerve  163 , ulnar nerve  164 , and other elongated anatomical structures  165  such as tendons, ligaments, and blood vessels. Of particular note is the prong  144  having a depth  136  and a connection  167  to the transverse  142 , forming a corner or recess such that the connection  167  is adapted to retain a nerve structure based on the depth from the connection  167  to a surface of a bone (radius  180  or ulna  182 ) in the surgical field. The insertion depth of the prong  144  based on the tower depth  136  affords the ulnar nerve a secure position adjacent the connection that is well above the surgical attachment activities occurring on the radius  180  for plate installation. 
         [0026]    While the system and methods defined herein have been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.