Abstract:
The system and method provides a retractor and use which gives the traditional ability to apply force and hold the surgical field open, but with the ability to select the depth, and shape of retraction tips for use during surgery, and in particular, spinal surgery. Any surgery may be carried out in an open surgical field with minimal patient trauma. A keyhole surgical opening accords a surgeon a maximum open operating field and necessitates only a minimal incision. An instrumentation-interchangeable tip junction facilitates the inserted support of interchangeable tips and may preferably include a connection shape which provides for a rotation lock.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to improvements in the field of surgical methods and instrumentation. More specifically, the invention relates to methods and instruments for spinal surgery which enable relatively deep tissue retraction. Most specifically, the invention relates to a surgical retractor having a plurality of interchangeable members which will enable the surgeon to select the proper shape and depth for the exact structures which need to be retracted at any point in the surgery. Direct visualization may be customized at each and every point in the surgery to reduce error and maximize efficiency and safety of the procedure.  
       BACKGROUND OF THE INVENTION  
       [0002]     Conventional cross member retractors are known which have been fitted with flat retractor members for insertion into a surgical field, providing the surgical field is large enough to accommodate the width of the flat retractor members. Conventional, relatively wide retractor members can produce a significant arc sweep during use. As a result, if the surgeon is working with an opening which can accommodate the retractor blades, and if the surgical field is of the proper depth and orientation to accommodate the sweeping motion, conventional scissor-type instrumentation can be used. Such instrumentation is overly invasive and minimally customizable to the unexpected needs which may present during the surgical procedure. The complications due to the mismatch between instrumentation and needs are well documented and include patient harm, longer recovery periods and additional healing from excess tissue displacement to complete the surgical procedure.  
         [0003]     Further, since the above described retractor is provided and usually utilized as an additional retractor to a main retraction system, it is likely that specialized circumstances are expected to invoke the need for supplemental retraction. However, having a supplemental retractor with the limitations of the above-described conventional retractor makes additional retraction capability only partially and narrowly marginally useful.  
         [0004]     In most surgical procedures, a fine degree of manipulation on the part of the surgeon is required. Often, the lack of ability for fine, subtle manipulation will result in a less than complete action in the surgical field, or the possibility of damage where manipulations are attempted with instrumentation ill suited to such subtle manipulation. Unfortunately, the level and orientation of the subtlety required may unexpectedly change throughout the surgical procedure.  
       SUMMARY OF THE INVENTION  
       [0005]     The system and method of the invention provides a retractor having the traditional ability to apply force and hold the surgical field open, but with the ability to select the depth, and shape of retraction tips for use during surgery, and in particular, spinal surgery. Any surgery may be carried out in an open surgical field with minimal patient trauma. The method and apparatus of the present invention employs a keyhole surgical opening which accords a surgeon a maximum open operating field and necessitates only a minimal incision. The open procedure allows direct visualization of the surgical field, either with the naked eye or through the use of optical devices such as surgical microscopes and/or loupes the like, and thereby eliminates the need to employ devices such as endoscopes. The keyhole surgical opening permits a surgeon to utilize normal binocular vision and provides ready access for surgical tools. A section above the point of connection of the interchangeable tips are diverted slightly outwardly to insure that the tips and their connector move out of visual alignment into the surgical field.  
         [0006]     In a most preferred embodiment, the members which extend into the surgical field angle apart from each other and then angle back into a parallel relationship before terminating at a connection end. This angled “jog” outward structure will be positioned below, but near the opening of the surgical field and can facilitate the co-location of supplementary structures ranging from suction to fiber optic illumination.  
         [0007]     The connection end can include insertion into a support collar on the interchangeable tips or the support collar can be located on the instrumentation side of the instrumentation-interchangeable tip junction. The inserted support of the interchangeable tips will preferably include a connection shape which provides for a rotation lock. The rotation lock can provide for a single rotational position or multiple positions. A simple, one-position rotational lock can be utilized for interchangeable retractors not expected to assume more than one position, while a multi-position lock can be utilized for more subtle applications. As by example, where the mechanical distance between the point of pivot and opening of the surgical field is short, the rotation to achieve a given sized opening will be more significant. Providing multiple, slightly changing angled connection will enable opening of the retractor to create a more bilaterally symmetrical position of the retractor blades. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:  
         [0009]      FIG. 1  is a perspective view of a retractor in accord with the present invention;  
         [0010]      FIG. 2  is a sectional view taken along lines  2 - 2  of a first terminal portion of the distal part of the main portion of the retractor of  FIG. 1  with respect to an interchangeable retractor tip seen in  FIG. 1  and illustrating one possible interconnection geometry;  
         [0011]      FIG. 3  is a sectional view taken along lines  3 - 3  as in  FIG. 2  but shown in mated position;  
         [0012]      FIG. 4  is a horizontal section taken along line  3 - 3  and illustrating one possible arrangement for a one-position rotational locking of the interchangeable retractor tip with respect to the distal part of the main portion of the retractor of  FIG. 1 ;  
         [0013]      FIG. 5  is a closeup section of a first angled portion which may facilitate a utility opening for fiber optic light cable, suction, and the like;  
         [0014]      FIG. 6  is a plan view of the angular displacement operation of the retractor system;  
         [0015]      FIG. 7  is a plan view of front of the retractor system seen in  FIG. 1  which emphasizes the double curvature for increased lateral displacement of the interchangeable tips of the retractor system;  
         [0016]      FIG. 7  is a plan view of front of the retractor system seen in  FIG. 1  which emphasizes the double curvature for increased lateral displacement of the interchangeable tips of the retractor system;  
         [0017]      FIG. 8  illustrates a plan view of an alternative shape for a front of the retractor system seen in  FIG. 1  which is completely linear for absolute minimum lateral displacement upon insertion into the surgical field;  
         [0018]      FIG. 9  illustrates a view of a first interchangeable tip seen with the tipmost end of the outwardly curved portion extending out of the page;  
         [0019]      FIG. 10  illustrates an interchangeable tip having a curved retractor tip but having an overall length shorter than that shown in  FIG. 9 ;  
         [0020]      FIG. 11  illustrates an interchangeable tip having a curved retractor tip but having an overall length shorter than that shown in  FIGS. 9 and 10 ;  
         [0021]      FIG. 12  illustrates a bottom view of the interchangeable retractor tips seen in  FIGS. 9-11 ;  
         [0022]      FIG. 13  illustrates an interchangeable bladed retractor member;  
         [0023]      FIG. 14  illustrates an interchangeable bladed retractor with a supported blade member having a length shorter than the supported blade member seen in  FIG. 13 ;  
         [0024]      FIG. 15  illustrates an interchangeable bladed retractor with a supported blade member having a length shorter than the supported blade member seen in  FIGS. 13 and 14 ;  
         [0025]      FIG. 16  illustrates a bottom view of the supported blade member interchangeable retractor tips seen in  FIGS. 13-15 ;  
         [0026]      FIG. 17  illustrates an exploded view of a more complex mounting system for the interchangeable tips;  
         [0027]      FIG. 18  is a cross sectional rendering of the components seen in  FIG. 17 ;  
         [0028]      FIG. 18  illustrates a cross sectional view of the joined components seen in  FIGS. 17-19 ;  
         [0029]      FIG. 20  is a view taken along line  20 - 20  of  FIG. 17  and illustrating a bottom view of an orientational adapter;  
         [0030]      FIG. 21  is a view taken along line  21 - 21  of  FIG. 17  and illustrating a top view of a threaded body of an interchangeable retractor tip;  
         [0031]      FIG. 22  is a lower plan view of a retractor assembly which includes both a curved tip and which supports a rectangular blade;  
         [0032]      FIG. 23  is a side view of the retractor assembly seen in  FIG. 22 ;  
         [0033]      FIG. 24  is a side view of the retractor assembly as seen in  FIG. 23 , but illustrating an embodiment having a series of lateral cuts;  
         [0034]      FIG. 25  is a side view of a flexible curved tip retractor;  
         [0035]      FIG. 26  is a view as seen in  FIG. 25  but illustrating the flexing action when force is applied to the curved portion;  
         [0036]      FIG. 27  is a lower side view of a retractor assembly which includes both a curved tip and which supports a shaped blade having an expanded circular lower area;  
         [0037]      FIG. 28  is a plan view of the retractor assembly seen in  FIG. 27 ;  
         [0038]      FIG. 29  is a plan view of an embodiment similar to the retractor assembly seen in  FIGS. 27 and 28 , but where a support post is cylindrical and stops short of extending to the lower edge of the expanded circular lower area;  
         [0039]      FIG. 30  is a lower side view of a retractor assembly which includes both a curved tip and which supports a shaped blade having an expanded pointed rectangular head lower area;  
         [0040]      FIG. 31  is a plan view of the retractor assembly seen in  FIG. 30 ; and  
         [0041]      FIG. 32  is a plan view of an embodiment similar to the retractor assembly seen in  FIGS. 27 and 28 , but where a support post is cylindrical and stops short of extending to the lower edge of the expanded pointed rectangular head lower area. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0042]     The description and operation of the retractor system will be best described beginning with reference to  FIG. 1  and referred to as a retractor system  21 . Retractor system  21  is particularly useful in providing a keyhole access opening. Retractor system  21  bears some general similarity to retractors generally known as Williams retractors, Gelpi retractors, Velpi retractors, Caspar retractors, or Ducker retractors; but the retractor system  21  differs therefrom with regard to some significant and important details.  
         [0043]     Retractor system  21  includes a first member  23  having a loop opening  25  and a pivot point  27 . Pivot point  27  is depicted as being a screw, but any method of providing stable pivot is an equivalent structure. Beyond the pivot point  27 , the first member is continuous with a curved member  29  which provides an outward curvature to create a central space  31 . Central space  31  provides a visual opening even when the retractor system  21  is closed. As will be seen, upon actuation of the retractor system  21 , the curved member  29  will help provide additional clearance around the surgical field.  
         [0044]     Curved member  29  is continuous with a first main retraction portion  33  which is generally at a right angle with respect to the main planar extent of the curved member  29  and is oriented to extend through a surgical field opening. At the end of the first main retraction portion  33 , the first main retraction portion  33  angles outward at a first bend  35  and into a first angled portion  37 . The first angled portion  37  extends through a second bend  39 , and then into a first terminal portion  41 . First terminal portion  41  is shown as leading into a first force fitting  45 . From the first force fitting  45 , a first interchangeable curved retractor body  47  extends. The first interchangeable curved retractor body  47  is seen as having an outwardly curved portion  49 .  
         [0045]     It is understood that the first force fitting  45  can be affixed to, continuous with or otherwise associated with either the first interchangeable curved retractor body  47  or the first terminal portion  41 . In the figures which immediately follow, the first force fitting  45  will be shown as associated with the first interchangeable curved retractor body  47 . Either orientation may have associated advantages. The system in which the first force fitting  45  is associated with the first interchangeable curved retractor body  47  will enable interchange of tips without the need to invert the retractor system  21 . The first interchangeable curved retractor body  47 , and first force fitting  45  may be referred to as a first interchangeable tip  51 .  
         [0046]     The other main structural portion of the retractor system  21  generally mirror those just described. A second member  53  having a loop opening  55  and shares the pivot point  27 , with the point  27  on second member  53  being underneath a portion of first member  23  which overlies it. Beyond the pivot point  27 , the second member  53  is continuous with a curved member  59  which provides a symmetric outward curvature to curved member  29 .  
         [0047]     Curved member  59  is continuous with a second main retraction portion  63  which is generally at a right angle with respect to the main planar extent of the curved member  59  which is generally at a right angle with respect to the main planar extent of the curved member  29  and is oriented to extend through a surgical field opening. Further, second main retraction portion  63  is generally parallel to first main retraction portion  33  and has the ability to move into close parallel relationship with first main retraction portion  33 .  
         [0048]     At the end of the second main retraction portion  63 , the second main retraction portion  63  angles outward at a third bend  65  and into a second angled portion  67 . The second angled portion  67  extends through a fourth bend  69 , and then into a second terminal portion  71 . Second terminal portion  41  is shown as leading into a second force fitting  75 , then to a second interchangeable curved retractor body  77  having an outwardly curved portion  79 . The second interchangeable curved retractor body  77 , and second force fitting  75  may be referred to as a second interchangeable tip  81 .  
         [0049]     Between the two main structural portions of the retractor system  10 , a number of different methods of holding the opening force may be applied. In the design shown, a conventional locking mechanism for enabling user selectably in applying displacement, opening force and immobilization of the position and holding force without having to continuously manually engage the retractor system  10 .  
         [0050]     The mechanism shown includes a toothed locking bar  85  which projects from the first member  23 . The toothed locking bar  85  passes through an opening  87  in the second member  53  and is engageable by a locking lever  89  affixed to pivot with respect to the second member  53  into and out of engagement with the toothed locking bar  85 . A spring  91  is shown positioned to urge the locking lever  89  into its positive engage position with respect to the toothed locking bar  85 , and against which physical release force of the locking lever  89  will occur.  
         [0051]     Referring to  FIG. 2 , one possible configuration for the interfitting of either the first and second terminal portions  41  and  71  is shown. Only first terminal portion  41  and first force fitting  45  will be illustrated, but the mechanism for these structures is expected to be identical and symmetric for the structures employed for the second terminal portion  71  and second force fitting  75 . Also, in  FIG. 2 , the first force fitting  45  is shown as continuous and associated with the first interchangeable curved retractor body  47 , but this need not be the case. Further, force fitting structure can, in different designs, be shared between the first interchangeable curved retractor body  47  and the first terminal portion  41 .  
         [0052]     First terminal portion  41  is seen to end with the provision of a reduced width portion  95 . It is to be understood that the reduced width portion  95  need not be round, and can be triangular, square, pentagonal, hexagonal, heptagonal or polygonal. The first terminal portion  41  and reduced width portion  95  can be such that, taking for example the first interchangeable tip  51  with its outwardly curved portion  49 , the first interchangeable tip  51  may assume a number of pre-specified orientations. For example, a reduced width portion which is triangular shaped can enable first interchangeable tip  51  to assume three orientations and a reduced width portion which is hexagonal shaped can enable first interchangeable tip  51  to assume six orientations. Other configurations can include a key projection which can interfit into 1, 2, 3 or more matching slots, where the matching slots are of defined angular orientation.  
         [0053]      FIG. 2  also illustrates a stepped blind bore within the first force fitting  45  and which includes a first bore  97  for fittably engaging a portion of the first terminal portion  41  just above the reduced width portion  95 . A second longitudinally deeper and narrower bore  99  interfits with the reduced width portion  95 . The bores  97  and  99  need not be circular, they can be of any shape, any cylindrical shape, smooth or not. Further, depending upon materials, the first force fitting  45  may have been shown in an overly exaggerated width. It is shown to emphasize that depending upon the materials selected, that some additional lateral material may be necessary to provide good hold and fit with respect to the structures including the reduced width portion  95  and optionally the portion of the first terminal portion  41  above it.  
         [0054]     Further, depending upon selection of materials, the first bore  97  might be eliminated and it is possible that the only bore within the first force fitting  45 , if such a first force fitting  45  is needed at all, might be a single bore seen as the second longitudinally deeper and narrower bore  99 .  
         [0055]     Further, other features can be employed to insure that the first interchangeable tip  51  remains vertically engaged with the first terminal portion  41 , regardless of the mating structures. Mechanical features can include a locking detent, or interference fit, or slight reverse interfering taper. Where the retractor system is made of ferromagnetic material, one or both of the first interchangeable tip  51  and first terminal portion  41  can be made of a magnetic material such that the first interchangeable tip  51  is magnetically attracted to and held by the first terminal portion  41 . Where other ferromagnetic materials or sensors may be present within the surgical field, it may be advantageous that only the reduced width portion  95  be magnetized, or perhaps where only the material of the first force fitting  45  at the face end of the second longitudinally deeper and narrower bore  99 . In another embodiment, both the second longitudinally deeper and narrower bore  99  and the reduced width portion  95  may be cylindrical and threaded. Many other possible joinder structures may have advantage in joining the first interchangeable tip  51  to the first terminal portion  41 . It should be remembered that the main force to be applied to this junction will be lateral and that the axial force of holding need not be great.  
         [0056]     Referring to  FIG. 3 , the first interchangeable tip  51  is shown as closely interfitting with and being supported by the first terminal portion  41 . It must be emphasized that the members seen in  FIG. 2  can be of any shape or orientation.  
         [0057]     Referring to  FIG. 4 , a horizontal section taken along line  3 - 3  of  FIG. 1  illustrates one of thousands of possible orientations and shapes for the first interchangeable tip  51  second longitudinally deeper and narrower bore  99  and first terminal portion  41 &#39;s reduced width portion  95  seen in  FIGS. 2 and 3 . Here, the reduced width portion  95  is seen as having a shape which includes a cylindrical diameter  101  and a flat portion  103  which mates with the complementary structures within the second longitudinally deeper and narrower bore  99 . One advantage of this particular orientation is that the shape for the first interchangeable tip  51  readily admits the reduced width portion  95  into the first bore, and then facilitates the location of the reduced width portion  95  into its matching shaped second longitudinally deeper and narrower bore  99  by turning until the flat portion  103  of the reduced width portion  95  is able to align with a complementary feature of second longitudinally deeper and narrower bore  99 . Thus the interfitting structures do not force the surgical practitioner to pull his attention away from the surgical field and take time and excess dexterity to interfit more demanding interlocking structures.  
         [0058]     Referring to  FIG. 5 , a closeup view of the first angled portion  37  located between the first main retraction portion  33  and first terminal portion  41  illustrates the possibility of forming a through bore  105  to facilitate passage of a utility conduit  107 . The utility conduit shown is a fiber cable  107 . Both the location and lower surface presented by first angled portion  37  permit easy access lighting of the tissues surrounding first and second interchangeable curved retractor tips  47  and  77 . This location will also likely not be optically obscured by foreign object matter or liquids as any liquids would tend to gravitationally run away from the presented end of fiber optic cable  107 . Other components can be utilized in place of the utility conduit shown, including suction, sensors, and the like.  
         [0059]     Referring to  FIG. 6 , a top view illustrating the action of movement of the retractor system  21  is shown. The ratchet enables the first and second members  23  and  53  to come together to the dashed line position while creating an enlarged central space  31 , and without the need for manual actuation of the locking lever  89 , which is urged into engagement with the toothed locking bar  85  by spring  91 .  
         [0060]     Referring to  FIG. 7 a  plan view of the retractor system  21  seen in  FIG. 1  is seen from the perspective of a position in front of the retractor system  21 . This view shows the extent of outward curvature of the outwardly curved portions  49  and  79 , and illustrates the relative lengths of the first and second terminal portions  41  and  71  with respect to the lengths of the first and second interchangeable tips  51  and  81 .  
         [0061]     Referring to  FIG. 8 a  portion of a second embodiment is shown in which the first and second main retraction portions  33  and  63 , first and second angled portions  37  and  67 , and the first and second terminal portions  41  and  71  are replaced by completely straight first and second main retraction portions  111  and  113  which include the reduced width portion  95  at their terminal ends. As can be seen, the first and second interchangeable tips  51  and  81  are engaged in the same manner as was seen in  FIGS. 1-4 . It is again understood, however, that the method for interconnection detailed in  FIGS. 2 and 3 , and particularly  FIG. 4  are only representative of one method of hundreds by which interconnected support of the first and second interchangeable tips  51  and  81  can be accomplished.  
         [0062]     The combination of the first and second interchangeable tips  51  and  81  with a retractor system  21  having straight first and second main retraction portions  111  and  113  will enable initial entry into a smaller size keyhole opening. As a result, it may be preferable to begin with retractor system  21  having straight first and second main retraction portions  111  and  113  to then be replaced with a retractor system  21  having first and second main retraction portions  33  and  63 , first and second angled portions  37  and  67 , and the first and second terminal portions  41  and  71 , in order to provide a surgical field with greater clearance. The views of  FIGS. 7 and 8  illustrate that for a given sized exterior patient surgical opening, a retractor system  21  with straight first and second main retraction portions  111  and  113  can fit but will be limited in retraction of the lower tissues by the surgical opening.  FIGS. 7 and 8  illustrate that with straight first and second main retraction portions  111  and  113 , the first and second interchangeable tips  51  and  81  can be brought more closely together to facilitate entry into a surgical opening. Some retraction of the opening can be accomplished to enable retractor system  21  having first and second main retraction portions  33  and  63 , first and second angled portions  37  and  67 , and the first and second terminal portions  41  and  71  so that the surgical field will have the structures, including first and second force fittings  45  and  75  further out of view in the surgical field.  
         [0063]     With regard to the first and second interchangeable tips  51  and  71 , a number of different lengths may be provided in order to maximally facilitate the different working depths the surgeon may encounter. As was the case with the initial use of a retractor system  21  having straight first and second main retraction portions  111  and  113  to then be replaced with a retractor system  21  having first and second main retraction portions  33  and  63 , first and second angled portions  37  and  67 , and first and second terminal portions  41  and  71 , the practitioner can begin work in the surgical opening with shorter lengths of first and second interchangeable tip  51  and  81 , and gradually change to longer lengths of first and second interchangeable tip  51  and  81  as the work progresses.  
         [0064]     Referring to  FIG. 9 a  view of the first interchangeable tip  51  is seen with the tipmost end of the outwardly curved portion  49  facing the viewer. This the first interchangeable tip  51  is the same as has been seen in  FIGS. 1-4 ,  7  &amp;  8 . Referring to  FIG. 10 , an interchangeable tip  121  having a curved retractor tip  123  having an overall length shorter than the curved retractor tip  47 . The dimensions of the force fitting  45  are the same as for interchangeable tip  51 . Although not referred to as a “first” or “second” interchangeable tip  121  or curved retractor tip  123 , it should be emphasized that the first and second interchangeable tip  51  and  81  may be made identical or can be made differently.  
         [0065]     Referring to  FIG. 11  an interchangeable tip  125  having a curved retractor tip  127  having an overall length shorter than the curved retractor tip  123  is shown.  FIGS. 9, 10 , and  11  are but three length sizes of interchangeable tip  51 ,  121 , and  125 . Other variations are possible, including differing diameter and different shapes of the outwardly curved portion  49 , as well as the absence or presence of outwardly curved portion  49 .  
         [0066]     Referring to  FIG. 12 , a bottom view of the interchangeable tip  51 , which is equivalent to the interchangeable tip  51 ,  121 , and  125  is shown. The bottom view seen in  FIG. 12  is the “footprint” of the interchangeable tip  51 , and will be seen with respect to the other embodiments to better illustrate the shapes thereof.  
         [0067]     Referring to  FIG. 13 , an interchangeable bladed retractor member  131  is illustrated with respect to the first terminal portion  41  seen in previous figures. The upper portion of the interchangeable bladed retractor member  131  is identical to that seen for the first interchangeable tip  51 , including the force fitting  45  and the reduced width portion  95  which interfits with the first bore  97  and second longitudinally deeper and narrower bore  99 , respectively. Below the force fitting  45 , a support post  133  supports a blade  135  on one side of the support post  133 . The blade  135  is seen extending slightly below the support post  133  by about the width of the support post  133 . Depending upon the method of attachment, the blade  135  can be attached to a cylindrical shaped support post  133  by surface welding, or in the alternative, the support post  133  can have a flattened area to support a weld with more surface area coverage.  
         [0068]     For the given width seen in  FIG. 13 , a interchangeable bladed retractor member  131  can have various lengths. Referring to  FIG. 14 , an interchangeable bladed retractor member  141  is also illustrated with respect to the first terminal portion  41  seen in previous figures. Again, the upper portion of the interchangeable bladed retractor member  131  is identical to that seen for the first interchangeable tip  51 . A slightly shorter support post  143  supports a blade  145  on one side of the support post  143 , with the blade  145  is seen extending slightly below the support post  143  by about the width of the support post  143 .  
         [0069]     Similarly, referring to  FIG. 15 , an interchangeable bladed retractor member  151  is illustrated. A still further shortened support post  153  supports a blade  155  on one side of the support post  153 , with the blade  155  is seen extending slightly below the support post  153  by about the width of the support post  153 . Referring to  FIG. 16 , a bottom view of the interchangeable bladed retractor member  131  is equivalent to a bottom view for the interchangeable bladed retractor members  141  and  151 .  FIG. 16  illustrates that the support post  133  (and the support posts  143  and  153 ) include a flattened area to better support the flat side of the blade  135 .  
         [0070]     Referring to  FIG. 17 , a more complex mounting system for the interchangeable tips is illustrated. An terminal portion  161  which can be either a first or second terminal portion is seen as having first shaped bore  163 , seen as opening downwardly. A locking nut  165  is configured to axially fit partially over at least the tip end of the terminal portion  161 . Depending upon the design, the action of the locking nut can be circumferentially compressive or it can depend from a rim (not seen) on the bottom periphery of the terminal portion which may engaged with an upper shoulder of the locking nut  165 .  
         [0071]     Below the locking nut  165  is seen an orientational adapter  171 . Orientational adapter  171  has an optional central land  173  which may for a separation between an upper projection  175  and a lower projection  177 . The land  173  is optional because the bores into which the upper projection  175  and lower projection  177  will fit have defined dimensions and consequently the presence of a land is un-necessary. The land  173  is un-necessary even where the effective widths and lengths of the upper projection  175  and lower projection  177  are the same.  
         [0072]     Below the orientational adapter  171 , an interchangeable tip  179 , which may be representative of any of the members  51 ,  81 ,  121 ,  125 ,  131 ,  141 , and  151 , is shown. Interchangeable tip  179  has a second, upwardly directed, threaded body bore  183  which complementary to the lower projection  177 . Interchangeable tip  179  has a force fitting threaded body  181  also has an external thread set  185  which are complementary to an internal thread set  187  carried within the locking nut  165 . Referring to  FIG. 18 , a sectional view of the components seen in  FIG. 17  are shown.  FIG. 19  is a sectional view illustrating the components seen in  FIGS. 17 and 18  in an attached position.  
         [0073]     Although the components seen in  FIGS. 17-19  are more complex, the selection of the first shaped bore  163 , upper projection  175  and lower projection  177 , and threaded body bore  183  enables the user to select a different orientational adapter  171  to achieve a different rotational lockup. Where the shapes of the bores  163  and  183 , along with their complementary projections  175  and  177 , admit only to a single orientational lockup, different orientational adapters  171  can be employed to achieve different angular positions of the members  51 ,  81 ,  121 ,  125 ,  131 ,  141 , and  151 . As before, where polygonal shapes are used for the bores  163  and  183 , along with their complementary projections  175  and  177 , different orientations can be achieved with a single orientational adapter  171 . However, the use of a geometry with a single rotational position invites the use of orientational adapters  171  in which the angle can be specifically set.  
         [0074]     Referring to  FIG. 20 , a view taken along line  20 - 20  of  FIG. 17  illustrates lower projection  177 . The shape of lower projection  177  is seen as having a generally cylindrical surface  187  with a flat side  189 . Referring to  FIG. 21 , a view taken along line  21 - 21  of  FIG. 17  illustrates details of the threaded body bore  183  and the upper end of the external thread set  185 . The shape of the threaded body bore  183  is seen as having a generally cylindrical surface  191  interrupted by a flat side  193 .  
         [0075]      FIGS. 22-33  illustrate a number of different shapes which are possible for use as the interchangeable retractor tips which could be substituted for structures  47 ,  77 ,  127 ,  131 ,  143 , and  151 . All of the structures  47 ,  77 ,  127 ,  131 ,  143 , and  151 , as well as the structures seen in  FIGS. 22-33  could be utilized in conjunction with any attachment system, including the systems outlined in  FIGS. 17-19  and the system outlined in  FIGS. 2-4 . Referring to  FIG. 22 , a retractor  201  includes a curved retractor tip  47  structure having a curved portion  49  curving toward a blade  135  of a length extending short of the curved portion  49  is shown. Referring to  FIG. 23 , a side view of the retractor assembly  201  is shown and gives a better visual illustration of the orientation of the curved portion  49  and blade  135 . In this configuration, the blade surface  135  can provide a relatively wider sweeping area and action while the slightly lower extending curved portion  49  of curved retractor tip  47  can provide a base gathering and collection action to insure that the area swept by the retractor assembly  201  will be clear.  
         [0076]     Referring to  FIG. 24 , a side view illustrates a retractor assembly  211  which has the same overall construction as was seen for retractor assembly  201 , except for the formation of a series of lateral cuts  213  in the upper surface of the curved portion  49 . The lateral cuts  213  form a series of teeth like projections which help stabilize any tissue gathered onto the curved portion  49  and helps to prevent any gathered tissues from sliding off, around the tip of the curved portion  49 . Avoiding slide off is particularly important in the moist surgical field.  
         [0077]     Referring to  FIG. 25 a  retractor assembly  215  having a construction similar to curved retractor tip  45  is seen. The main length of the body  217  is made of a flexible material. The flexible material construction may extend throughout the body  217 , or the body  217  may be differentially hardened. Referring to  FIG. 26 , the flexing of the body  217  is shown. Note that the curved portion  49  is not seen as straightening to any appreciable extent. This can be achieved naturally by providing more strength in the curved portion  49  or by the natural geometry which enables the body  217  to have the greatest flexure along the body  217  length. Body  217  can also have a taper to help control its flexing. The ability of the retractor assembly  215  to flex gives it the ability to avoid tissue damage at the maximum depth over which retraction occurs. The maximum depth is an area swept farthest from the surgical practitioner&#39;s view and the area most prone to contact with structures not already revealed at the surgical opening. This feature enables a gentler mode of retraction, especially where used with softer or more delicate tissues.  
         [0078]     Referring to  FIG. 27 , a retractor assembly  221  includes a curved retractor tip  47  structure having a curved portion  49  curving toward a specially shaped blade  223  of a length extending short of the curved portion  49 . Referring to  FIG. 28 , a side view of the retractor assembly  223  is shown and gives a better visual illustration of the shape of the blade  223 . Blade  223  is in the shape of an inverted lollipop or keyhole shape which blends into a linear shape extending upward. This shape provides a wider retraction at a relatively lower depth inside the surgical field.  
         [0079]     Referring to  29 , a retractor  225  includes the shaped blade  223  seen in  FIGS. 27 and 28 , but in lieu of the curved retractor tip  47 , a shortened support post  227  extends only to a point significantly short of the lowest extent of the specially shaped blade  223 . This enables the lower shape of the retractor assembly  225  to have a shape and contour matching the specially shaped blade  223 .  
         [0080]     Referring to  FIG. 30 , a retractor assembly  231  includes a curved retractor tip  47  structure having a curved portion  49  curving toward a specially shaped blade  233  of a length extending short of the curved portion  49 . Referring to  FIG. 31 , a side view of the retractor assembly  233  is shown and gives a better visual illustration of the shape of the blade  233 . Blade  233  is in the shape of a diamond head or pointed square shape which blends into an upper linear portion. This shape provides a wider retraction at a relatively lower depth inside the surgical field, but the pointed lateral corners also provide a wider retraction slightly displaced from the lower corner or tip.  
         [0081]     Referring to  32 , a retractor  235  includes the shaped blade  233  seen in  FIGS. 30 and 31 , but in lieu of the curved retractor tip  47 , a shortened support post  237  extends only to a point significantly short of the lowest extent of the specially shaped blade  223 , seen below the lateral corners but above the lowermost corner. This enables the lower shape of the retractor assembly  225  to have a shape and contour matching the specially shaped blade  233 .  
         [0082]     While the present system has been described in terms of a minimal incision maximal access spine surgery instruments and method, and includes any method of actuation, despite being shown as being centrally discussed as a manually actuatable with a scissors-like device, one skilled in the art will realize that the structure and techniques of the present system can be applied to many appliances including any appliance which utilizes the several aspects of the embodiments of the instrumentation of the system or any process which utilizes the steps of the inventive system.  
         [0083]     Although the system of the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the system, retractors, and components may become apparent to those skilled in the art without departing from the spirit and scope of the inventive system. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.