Abstract:
A filament retaining washer for mounting about the shank of a bone screw deployed in a bone whereby to retain the filament to the bone, the filament retaining washer comprising a structure having a screw hole extending therethrough for receiving therein the shank of the bone screw deployed in the bone, whereby to secure the structure to the bone, the screw hole defining a first axis, and the structure having a filament hole extending therethrough for receiving a filament therein so as to retain the filament to the structure, the filament hole defining a second axis extending substantially perpendicular to the first axis.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to surgical apparatus and methods in general, and more particularly to surgical apparatus and methods for fixing bone and soft tissue in place during trauma and reconstructive surgery.  
         BACKGROUND OF THE INVENTION  
         [0002]    Bone fixation, sometimes also referred to as fracture fixation, is an established art. Fixation screws, and fixation screws in combination with metal plates, are widely used in the art to stabilize bone so as to facilitate healing.  
           [0003]    Surgical cables, and surgical cables in combination with metal plates, are also well known in the bone fixation art. Cables, and cables in combination with plates, are generally used in situations where the use of screws, or screws in combination with plates, is not suitable. By way of example, cables, and cables in combination with plates, are frequently used in the fixation of long oblique fractures resulting from high energy trauma such as a motor vehicle accident. By way of further example, screw fixation is frequently not adequate for fractures that are highly comminuted, and fixation with cables, or cables in combination with plates, is required.  
           [0004]    Cables are also sometimes used in conjunction with screws, and in conjunction with screws in combination with plates. By way of example, cables may be used in conjunction with screws, and screws in combination with plates, where a screw strips its threads in deployment, or where screws, or screws in combination with plates, is deemed insufficient for the fixation at hand.  
           [0005]    With cable fixation, it is customary to encircle the subject bone with the body of the cable, and then to secure the two free ends of the cable together with a deformable crimp so as to effect fixation.  
           [0006]    In general, cable fixation on the shaft of a so-called “long bone” does not present a significant problem with migration, inasmuch as this portion of the bone is substantially tubular in geometry. However, the ends of these long bones typically have a significant flare in their geometry. As a result, tightening of the encircling cable often causes the cable (and crimp) to migrate toward the narrower section of the bone. Such migration can displace the cable sufficiently far from its intended location as to significantly loosen, or render ineffective, encirclement of the bone segments.  
           [0007]    Thus, there is a need for an improved apparatus and method which will permit bone fixation to be effected with screws and cable.  
           [0008]    There further exists a need for an improved apparatus and method for effecting bone fixation with cable, such that the cable will not slide along the bone during tightening of the cable.  
           [0009]    In addition to the foregoing, in many situations, soft tissue may need to be attached to bone. By way of example, a ligament may need to be attached to bone during trauma and reconstructive surgery. In some of these situations, bone fixation may also be necessary, and such bone fixation may involve the use of screws, cables and plates, either alone or in combination with one another.  
           [0010]    Thus, there is a need for an improved apparatus and method for attaching soft tissue to bone.  
           [0011]    There further exists a need for an improved apparatus and method for attaching soft tissue to bone, where screws may be used to help effect fixation to bone.  
         SUMMARY OF THE INVENTION  
         [0012]    Accordingly, one object of the present invention is to provide improved apparatus for use in bone fixation.  
           [0013]    Another object of the present invention is to provide improved apparatus for use in bone fixation which involves the use of bone screws, metal plates and/or cables.  
           [0014]    Still another object of the present invention is to provide an improved method for bone fixation.  
           [0015]    Yet another object of the present invention is to provide improved apparatus for attaching soft tissue to bone.  
           [0016]    And another object of the present invention is to provide improved apparatus for attaching soft tissue to bone, where screws may be used to help effect fixation to bone.  
           [0017]    A further object of the present invention is to provide an improved method for attaching soft tissue to bone.  
           [0018]    These and other objects of the present invention are addressed by the provision and use of a novel filament retaining washer for mounting about the shank of a bone screw deployed in a bone whereby to retain the filament to the bone, the filament retaining washer comprising a structure having a screw hole extending therethrough for receiving therein the shank of the bone screw deployed in the bone, whereby to secure the structure to the bone, the screw hole defining a first axis, and the structure having a filament hole extending therethrough for receiving a filament therein so as to retain the filament to the structure, the filament hole defining a second axis extending substantially perpendicular to the first axis.  
           [0019]    In another form of the invention, there is provided a filament retaining washer for mounting about the shank of a bone screw deployed in a bone whereby to retain the filament to the bone, the filament retaining washer comprising a body; a downwardly projecting extension connected to the body and having a screw hole extending therethrough for receiving therein the shank of the bone screw deployed in the bone, whereby to secure the downwardly projecting extension to the bone, the screw hole defining a first axis; and an upwardly projecting extension connected to the body and having a filament hole extending therethrough for receiving a filament therein so as to retain the filament to the upwardly projecting extension, the filament hole defining a second axis extending substantially perpendicular to the first axis.  
           [0020]    And in another form of the invention, there is provided a system for securing an object to a bone, the system comprising a bone screw; a washer comprising a body, a downwardly projecting extension connected to the body and having a screw hole extending therethrough for receiving therein the shank of the bone screw deployed in the bone, whereby to secure the downwardly projecting extension to the bone, the screw hole defining a first axis, and an upwardly projecting extension connected to the body and having a filament hole extending therethrough, for receiving a filament therein so as to retain the filament to the upwardly projecting extension, the filament hole defining a second axis extending substantially perpendicular to the first axis; and a filament received by the filament hole, the filament securing the object to the bone.  
           [0021]    In another form of the invention, there is provided a method for securing an object to a bone, the method comprising providing a screw, a filament and a suture retaining washer, the suture retaining washer comprising a body, a downwardly projecting extension connected to the body and having a screw hole extending therethrough for receiving therein the shank of a bone screw deployed in the bone, whereby to secure the downwardly projecting extension to the bone, the screw hole defining a first axis, and an upwardly projecting extension connected to the body and having a filament hole extending therethrough for receiving a filament therein so as to retain the filament to the upwardly projecting extension, the filament hole defining a second axis extending substantially perpendicular to the first axis; securing the washer to the bone with the screw, with the filament extending through the filament hole; and using the filament to secure the object to the bone.  
           [0022]    And in another form of the invention, there is provided a method for securing an object to a bone, the method comprising providing a screw, a filament and a suture retaining washer, the suture retaining washer comprising a structure having a screw hole extending therethrough for receiving therein the shank of the bone screw deployed in the bone, whereby to secure the structure to the bone, the screw hole defining a first axis, and the structure having a filament hole extending therethrough for receiving a filament therein so as to retain the filament to the structure, the filament hole defining a second axis extending substantially perpendicular to the first axis; securing the washer to the bone with the screw, with the filament extending through the filament hole; and using the filament to secure the object to the bone.  
           [0023]    The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular devices, assembly and method embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:  
         [0025]    [0025]FIG. 1 is a perspective view showing a novel surgical fastening system securing together two bone segments;  
         [0026]    [0026]FIG. 2 is perspective view of a cable retaining washer which forms part of the surgical fastening system shown in FIG. 1;  
         [0027]    [0027]FIG. 3 is an exploded side view, in section, of a bone screw, cable retaining washer and bone plate which form part of the surgical fastening system shown in FIG. 1;  
         [0028]    [0028]FIG. 4 is a perspective view of an alternate form of cable retaining washer formed in accordance with the present invention;  
         [0029]    [0029]FIG. 5 is a perspective view of another alternative form of cable retaining washer formed in accordance with the present invention;  
         [0030]    [0030]FIG. 6 is a perspective view of still another alternative form of cable retaining washer formed in accordance with the present invention;  
         [0031]    [0031]FIG. 7 is a perspective view of yet another alternative form of cable retaining washer formed in accordance with the present invention;  
         [0032]    [0032]FIG. 8 is a perspective view of a bone screw, cable retaining washer and bone plate which comprise another embodiment of the present invention;  
         [0033]    [0033]FIG. 9 is a side view, in section, of the apparatus shown in FIG. 8;  
         [0034]    [0034]FIG. 10 is a side view, partially in section, showing a bone screw securing the cable retaining washer of FIG. 2 directly to a bone;  
         [0035]    [0035]FIG. 11 is a perspective view showing an alternative form of surgical fastening system formed in accordance with the present invention;  
         [0036]    [0036]FIG. 12 is a perspective view of a suture retaining washer which forms part of the surgical fastening system shown in FIG. 11;  
         [0037]    [0037]FIG. 13 is a partial sectional view of a bone screw and suture retaining washer which form part of the surgical fastening system shown in FIG. 11;  
         [0038]    [0038]FIG. 14 is a perspective view showing a suture loop attaching a piece of surgical mesh to a suture retaining washer; and  
         [0039]    [0039]FIG. 15 is a view similar to that of FIG. 11, except showing the assembly of FIG. 14 secured to a bone. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0040]    Looking first at FIGS.  1 - 3 , there is shown a surgical fastening system  5  which comprises one preferred form of the invention.  
         [0041]    Surgical fastening system  5  generally comprises a bone plate  6 , a plurality of bone screws  9 , a plurality of cable retaining washers  12 , and a plurality of cable loops  15 . As used herein, the term “cable” is intended to encompass braided cable, wire and the like.  
         [0042]    Bone plate  6  is deployed so that the bone plate extends across the fracture line  18  of two bone segments  20 ,  21 . The heads  25  (FIG. 3) of bone screws  9  engage cable retaining washers  12 , while the shanks  27  of bone screws  9  extend through screw holes  30  in cable retaining washers  12 , through screw holes  33  in bone plate  6  and into bone segments  20 ,  21 , whereby to secure bone plate  6  to bone segments  20 ,  21  and, the in process, to secure bone segments  20 ,  21  together. Additionally, cable loops  15  encircle bone segments  20 ,  21  and are secured to cable retaining washers  12 , whereby cable loops  15  further secure bone segments  20 ,  21  to bone plate  6  and, as a result, to one another.  
         [0043]    Bone plate  6  is of the sort well known in the art. By way of example but not limitation, bone plate  6  generally comprises an elongated body  35  penetrated by the aforementioned screw holes  33 . The bone plate&#39;s top surface  36  generally includes recesses  40  about the top ends of screw holes  33 ; in conventional bone plate applications, recesses  40  receive the semi-spherical undersides of the heads  25  of bone screws  9 .  
         [0044]    Bone screws  9  are also of the sort well known in the art. Bone screws  9  comprise the aforementioned head  25  and the aforementioned shank  27 .  
         [0045]    Cable restraining washer  12  comprises a body  45  having a bottom surface  48  (FIG. 3) for engaging the top surface  36  of bone plate  6 , a downwardly projecting extension  50  for seating in a recess  40  in bone plate  6 , and an upwardly projecting extension  55  for receiving and restraining at least one cable loop  15 .  
         [0046]    Downwardly, projecting extension  50  preferably has a semi-spherical configuration similar to the semi-spherical underside of a head  25  of a bone screw  9  so as to seat in one of the recesses  40  commonly formed in bone plate  6 .  
         [0047]    A recess  60  is formed in body  45 , in alignment with the downwardly projecting extension  50  and screw hole  30 . Recess  60  is sized so as to receive the head  25  of a bone screw  9 , and screw hole  30  is sized so as to receive the shank  27  of a bone screw  9 . In this way, cable restraining washer  12  can be mounted to bone plate  6  so that the washer&#39;s downwardly projecting extension  50  seats in a recess  40  formed in bone plate  6 , and a bone screw  9  may be passed through the cable retaining washer  12  so that the head  25  of the screw  9  is seated in the washer&#39;s recess  60  and so that the shank  27  of the bone screw  9  passes through the washer&#39;s screw hole  30 , through the screw hole  33  formed in bone plate  6 , and into a bone segment  20 ,  21 , whereby to secure the cable retaining washer  12  and bone plate  6  to one another, and to a bone segment  20 ,  21 .  
         [0048]    Cable restraining washer  12  also comprises the upwardly projecting extension  55  for receiving and retaining one or more cable loops  15 . More particularly, cable retaining washer  12  also comprises at least one cable hole  65  extending perpendicular to the axis of the washer&#39;s screw hole  30 . Cable hole  65  is sized to slidingly receive a cable loop  15 . A threaded set screw hole  67  extends downwardly from the top surface  70  of the washer&#39;s upwardly projecting extension  55 . The bottom end of set screw hole  67  intersects the at least one cable hole  65  (FIG. 3). A set screw  73  is positioned in set screw hole  67 . Set screw  73  may be tightened down so as to engage a cable loop  15  extending through a cable hole  65 , whereby to secure that cable loop to the cable retaining washer  12  and, as a result, to secure that cable loop to a bone segment  20 ,  21 .  
         [0049]    Surgical fastening system  5  is intended to be used as follows.  
         [0050]    First, bone plate  6  is positioned against bone segments  20 ,  21 . Then bone screws  9  are used to secure cable retaining washers  12  and bone plate  6  to one another and to bone segments  20 ,  21 . Next, cable loops  15  are passed through cable holes  65  in the cable retaining washers  12 , and then set screws  73  are used to lock cable loops  15  to the washers.  
         [0051]    Looking next at FIG. 4, there is shown a cable retaining washer  112  which comprises an alternative form of the invention. Cable retaining washer  112  is substantially the same as the cable retaining washer  12  described above, except that it also includes a second upwardly projecting extension  55 , along with that extension&#39;s associated cable holes(s)  65 , set screw hole  67 , and set screw  73 .  
         [0052]    Looking next at FIG. 5, there is shown a cable retaining washer  212  which comprises another alternative form of the invention. Cable retaining washer  212  is substantially the same as the cable retaining washer  12  described above, except that its upwardly projecting extension  255  lacks the set screw hole  67  and set screw  73  for locking a cable loop  15  within a cable hole  65 . Instead, with cable retaining washer  212 , upwardly projecting extension  255  is formed so as to be crimpable, whereby to mechanically lock a cable loop  15  within a cable hole  65 . In one preferred form of the invention, upwardly projecting extension  255  is formed with a trapezoidal cross-section such as that shown in FIG. 5, whereby to facilitate crimping of the upwardly extending projection  255  about the cable.  
         [0053]    Looking next at FIG. 6, there is shown a cable retaining washer  312  which comprises another alternative form of the invention. Cable retaining washer  312  is substantially the same as the cable retaining washer  212  described above, except that it includes a second upwardly projecting extension  255 .  
         [0054]    Looking next at FIG. 7, there is shown a cable retaining washer  412  which comprises another alternative form of the invention. Cable retaining washer  412  is substantially the same as the cable retaining washer  312  described above, except that each of the upwardly projecting extensions  255  has only one cable hole  65  formed therein.  
         [0055]    In the cable retaining washers  12 ,  112 ,  212 ,  312  and  412  described above, the downwardly projecting extension  55  has a semi-spherical configuration so as essentially replicate the semi-spherical underside of the head  25  of a bone screw  9 , whereby it may be received in the recess  40  formed in bone plate  6 . However, forming the downwardly projecting extension  55  with a semi-spherical configuration can sometimes result in the cable retaining washer turning about the axis of its screw hole  30 .  
         [0056]    To guard against this, and looking now at FIGS. 8 and 9, there is shown a bone plate  506  which is provided with an elongated recess  540  and a cable retaining washer  512 . Cable retaining washer  512  is substantially the same as the cable retaining washer  212  shown in FIG. 5, except that the downwardly projecting extension  50  of cable retaining washer  212  (FIG. 5) has been replaced with a downwardly projecting extension  550  having a cross-sectional profile matching that of the bone plate&#39;s elongated recess  540 . If desired, the cable retaining washers  12 ,  112 ,  312 , and  412  may also have their downwardly projecting extensions  50  replaced with similar downwardly projecting extensions  550 , whereby they can mate securely with recesses  540  of a bone plate  506 .  
         [0057]    It is also possible to use the cable retaining washers of the present invention without a bone plate. In this case, the bone screw passes through the cable retaining washer and directly into a bone segment  20 ,  21 . If desired, cable retaining washers  12 ,  112 ,  212 ,  312  and/or  412  may be used in this way, with the downwardly projecting extensions bearing against, and generally penetrating into, bone segment  20 ,  21 . See, for example, FIG. 10, where cable retaining washer  12  is shown engaging a bone segment  20 ,  21 .  
         [0058]    Alternatively, if desired, the bottom surface of the cable retaining washer can be modified so as to reduce, or entirely remove, the downwardly projecting extension.  
         [0059]    Looking next at FIGS.  11 - 13 , there is shown a suture retaining washer  612  which comprises another form of the invention. Suture retaining washer  612  comprises a body  645 . Suture retaining washer  612  also comprises a downwardly projecting extension  650  for seating in a recess  40  of a bone plate  6  or for engaging the outer surface of a bone segment  20 ,  21 . Suture retaining washer  612  also comprises at least one upwardly projecting extension  655  for receiving and retaining at least one suture loop  615 .  
         [0060]    A screw hole  30  is formed in downwardly projecting extension  650  and a recess  60  is formed in body  645 . Recess  60  is sized to receive the head  25  of a bone screw  9 , and screw hole  30  is sized to receive the shank  27  of bone screw  9 . In this way, suture retaining washer  612  can be mounted to bone plate  6  so that the downwardly projecting extension  650  seats in a corresponding recess  40  in bone plate  6 , and a bone screw  9  may be passed through the suture retaining washer  612  so that the head  25  of the screw  9  is seated in the washer&#39;s recess  60  and the shank  27  of the bone screw  9  passes through the washer&#39;s screw hole  30 , through the screw hole  33  in bone plate  6 , and into a bone segment  20 ,  21 , whereby to secure suture retaining washer  612  and bone plate  6  to one another, and to a bone segment  20 ,  21 . Alternatively, suture retaining washer  612  can be mounted directly to a bone segment  20 ,  21  by seating downwardly projecting extension  650  against a bone segment  20 ,  21 , and then passing a bone screw  9  through the suture retaining washer  612  so that the head  25  of the screw  9  is seated in the washer&#39;s recess  60  and the shank  27  of the bone screw  9  passes through the washer&#39;s screw hole  30  and into a bone segment  20 ,  21 .  
         [0061]    Suture retaining washer  612  also comprises at least one upwardly projecting extension  655  for receiving and retaining one or more loops  615 . More particularly, suture retaining washer  612  also comprises at least one upwardly projecting extension  655 , with each upwardly projecting extension having at least one suture hole  65  extending perpendicular to the axis of the washer&#39;s screw hole  30 . Suture hole  65  is sized to slidingly receive a suture loop  615 .  
         [0062]    If desired, suture loops  615  can be used to secure soft tissue to bone segments  20 ,  21 . Alternatively, and looking next at FIGS. 14 and 15, suture loops  615  can be used to attach a surgical mesh  675  to bone segments  20 ,  21 .