Patent Abstract:
A bone plate includes (a) a body having a first surface which, in an operative configuration, faces away from a bone on which the plate is to be mounted and a second surface, which in the operative configuration, faces the bone, the body including a first section extending along a first longitudinal axis and a second section extending along a second longitudinal axis angled with respect to the first longitudinal axis; (b) a first hole extending through the body from the first surface to the second surface and defining a first hole axis, the first hole being structured to lockingly engage a head of a first bone anchor inserted therein such that a shaft of the first bone anchor extends along the first hole axis; and (c) a second hole extending through the body and spaced apart from the first hole. The second hole defines a second hole axis and is structured to lockingly engage a head of a second bone anchor inserted therein such that a shaft of the second bone anchor extends along the second hole axis. The first and second hole axes defines a single plane and intersecting at a point on a side of the bone plate facing the second surface.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation application of U.S. patent application Ser. No. 13/930,411 filed Jun. 28, 2013, which is a continuation of U.S. patent application Ser. No. 13/092,625, filed on Apr. 22, 2011, which is a continuation of U.S. patent application Ser. No. 10/843,113, filed on May 11, 2004, now Pat. No. 7,951,176, which in turn claims priority to U.S. Provisional Patent Application Ser. No. 60/474,279, filed on May 30, 2003. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to bone plates, and more specifically, to bone plates for the fixation of parts of a fractured bone, preferably long bones, including the femur and the tibia. 
       BACKGROUND OF THE INVENTION 
       [0003]    A bone plate is a plate that is fastenable to the surface of a bone typically at both sides of a fracture to support and/or stabilize the fracture. Bone plates have typically been attached to the bone with bone screws that extend from the plate into the bone. In some examples, the head of the bone screw is locked to the plate (e.g., by threaded engagement between the screw head and the bone plate) and in other plates the head of the screw is free to angulate with respect to the plate, such that the screw may be placed in the bone at a surgeon-selected angle. In yet other examples, the screw head may cooperate with the bone plate to provide compression or distraction of the fracture (i.e., to push the bone fragments towards or away from one another). 
         [0004]    When treating certain types of fractures, such as that of the proximal portion of the femur, there may be high stresses at the bone-screw and/or screw-plate interfaces. Several different types of bone plates have been developed to accommodate these high stresses. In one example known as a “blade plate,” the bone plate may have a blade-shaped portion that extends approximately perpendicularly to the plate, and extends into a channel formed in the bone through the fracture site. In another example, a lag screw may extend from a barrel portion of the plate and through the fracture site. With both of these systems, however, a large amount of bone must be removed to accommodate the blade or barrel. In addition, the surgical procedures are technically difficult, as the bone must be removed with precision in order to allow proper positioning of the bone plate on the bone. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention in one embodiment is directed to a bone plate having a longitudinal axis and comprising an upper surface, a lower surface, a first hole for engaging an end portion of a first bone anchor, the first hole being configured and adapted to fix a shaft of the first bone anchor along a first axis, and a second hole spaced apart from the first hole along the longitudinal axis, the second hole for engaging an end portion of a second bone anchor and configured and adapted to fix a shaft of the second bone anchor along a second axis. The first hole and the second hole may be configured such that the first axis and the second axis define a single plane and intersect at a point below the lower surface of the bone plate. The bone plate may further include a third hole for engaging an end portion of a third bone anchor such that a shaft of the third bone anchor is fixed along a third axis, wherein the third hole preferably is located between the first and second holes and the third axis lies at an angle relative to the plane defined by the first and second axes. The first, second, and third holes may be positioned along the longitudinal axis of the bone plate. A shaft of the first bone anchor may contact or nearly contact a shaft of a second bone anchor. The first, second and third bone anchors may be bone screws, blades, or other anchors known to one of ordinary skill in the art for engaging bone. 
         [0006]    According to one illustrative embodiment, the plane defined by the first and second axes may lay at an angle relative to a plane bisecting the bone plate along the longitudinal axis and or the central axis. Additionally or alternatively, the first and second holes may be configured such that the first and second axes define an acute angle at the point of intersection. 
         [0007]    Preferably, at least one of the first and second holes may be threaded to engage threads on the end portion of a bone screw, or alternatively, at least one of the first and second holes may be dimensioned and configured for an end of a bone screw to be press fit therein. Preferably, at least one of the first and second holes are configured so that the bone anchor will be fixed to the bone plate when engaged therewith at a predetermined angle with respect to the plane formed by the lower surface of the bone plate at the location of the respective hole. The angle formed between the lower surface of the bone plate and the axis of one of the bone anchors may be approximately perpendicular, and optionally the angle between the axis of the second bone anchor and the lower surface forms an acute angle. More preferably, the angles of the axes of the bone anchors which are predetermined by the nature of the bone anchors engagement with the respective hole, are such that the bone anchors will form a truss formation. More preferably, at least one or more holes in the bone plate are oriented such that bone anchors engaged in the bone plate are fixed, and at least a first bone anchor, preferably its tip, contacts at least a second bone anchor along the length of the second bone anchor. 
         [0008]    The bone plate may also include at least one combination hole for receiving a bone screw, the combination hole having a first portion and a second portion, wherein the first portion defines a substantially circular outer periphery defining a first center point, and the second portion defines an elongated outer periphery that defines a second center point. The elongated outer periphery may be elongated in a direction substantially parallel to the longitudinal axis of the plate, and the second portion may overlap the first portion. A plurality of threads may be disposed on the first portion of the combination hole for threadably engaging the head of a bone screw. The second portion of the combination hole may be configured and dimensioned to engage a substantially spherical head of a bone screw. 
         [0009]    The present invention in another embodiment is also directed to bone plating systems including a bone plate and various combinations of bone anchors (e.g., bone screws, blades, etc.). The bone plate may also include a first end and a second end, in which the first end is configured for following the contour of the bone. The first end may include a hook configured to engage bone tissue. The hook may include an edge located below the lower surface of the bone plate for penetrating into bone tissue. The edge of the hook may be formed by two spaced apart talons. 
         [0010]    The bone plate may also comprise a first section having a first longitudinal axis, a second section defining a second longitudinal axis, and a transition section connecting the first section to the second section such that an included angle is defined between the first longitudinal axis and the second longitudinal axis. The included angle between the first and second longitudinal axes may be obtuse, acute or approximately right angled. The first section, the second section and the transition sections may be integral with one another made from a single piece of material, or alternatively joined together by techniques known to one of ordinary skill in the art. Additionally, the first section may be longer than the second section, and the transition section may connect the first section to the second section such that the bone plate is substantially L-shaped or T-shaped. The transition section may also be bent or twisted to connect the first section to the second section which may locate the second section in a plane different from that of the first section. The upper surface of the transition section may be substantially S-shaped. The lower surface of the first, second and transition sections may also define radius of curvature along their longitudinal axes. 
         [0011]    The present invention is also generally directed to a method of using a bone plate according to the present invention for reducing bone fractures. The method comprises the steps of affixing an embodiment of a bone plate according to the present invention across the gap of a fracture zone and engaging the threaded head of a bone screw in a threaded hole of the bone plate so as form a threaded locked engagement. The threaded hole is configured for threaded locked engagement with the threaded head of the bone screw. The threaded hole may fix the bone screw along an axis at such an angle relative to the lower surface of the bone plate such that upon the threaded locked engagement of the bone screw with the bone plate, the gap of the bone fracture is reduced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    To facilitate an understanding of the characteristics, structure and operation of the invention, preferred exemplary features of the invention are described in the accompanying discussion, it being understood that the invention in its various embodiments is not limited to the preferred examples illustrated and, wherein similar reference characters denote similar elements throughout the several views or embodiments, and wherein: 
           [0013]      FIG. 1  is a side view of a first illustrative embodiment of a bone plate according to the present invention, shown attached to a proximal portion of a fractured femur by a plurality of bone screws; 
           [0014]      FIG. 2  is a top view of a portion of the bone plate of  FIG. 1 ; 
           [0015]      FIG. 3  is a cross-sectional view of a portion of the bone plate of  FIG. 1 ; taken along line of  FIG. 2 ; 
           [0016]      FIG. 4  is a perspective, partial view of the lower surface of the bone plate of  FIG. 1 , with a portion of the bone plate shown in cross-section; 
           [0017]      FIG. 5  is a front view of the bone plate of  FIG. 1 ; 
           [0018]      FIG. 6  is a perspective view of a bone screw having a threaded head for use with a bone plate according to one embodiment of the present invention; 
           [0019]      FIG. 7  is a cross-sectional view of the bone screw of  FIG. 6 ; 
           [0020]      FIG. 8  is a plan view of a spiral blade for use with a bone plate according to one embodiment of the present invention; 
           [0021]      FIG. 9  is a perspective view of the spiral blade of  FIG. 8 ; 
           [0022]      FIG. 10  is a plan view of the bone plate of  FIG. 1  having an alternate bone screw configuration 
           [0023]      FIG. 11A  is a top view of a combination hole provided in a bone plate according to one embodiment of the present invention; 
           [0024]      FIG. 11B  is a cross-sectional view of the combination hole of  FIG. 11A , taken along line XII-XII of  FIG. 11A ; 
           [0025]      FIG. 12A  is a top view of a different embodiment of a combination hole. 
           [0026]      FIG. 12B  is a cross-sectional view of the combination hole of  FIG. 12A , taken along line A-A of  FIG. 12A . 
           [0027]      FIG. 13  is a cross-sectional view of another illustrative embodiment of a bone plate according to the present invention; 
           [0028]      FIG. 14  is a perspective, partial view of the lower surface of the bone plate of  FIG. 13 , with a portion of the bone plate shown in cross-section; 
           [0029]      FIG. 15  is a side view of a still further illustrative embodiment of a bone plate according to the present invention; 
           [0030]      FIG. 16  is a top view of the bone plate of  FIG. 15 ; 
           [0031]      FIG. 17  is a perspective partial view of the bone plate of  FIG. 15 ; 
           [0032]      FIG. 18  is a top view of another illustrative embodiment of a bone plate according to the present invention; 
           [0033]      FIG. 19  is a cross-sectional, partial view of the bone plate of  FIG. 18 , taken along the line XIX-XIX of  FIG. 18 ; 
           [0034]      FIG. 20  is a cross-section, partial view of the bone plate of  FIG. 18 , taken along the line XX-XX of  FIG. 18 ; 
           [0035]      FIG. 21  is a perspective, partial view of the bone plate of  FIG. 18 ; 
           [0036]      FIG. 22  is a frontal, partial, perspective view of the bone plate of  FIG. 18 ; 
           [0037]      FIG. 23  is a top perspective view a further illustrative embodiment of a bone plate according to the present invention; 
           [0038]      FIG. 24  is a perspective view of the bone plate of  FIG. 23 ; 
           [0039]      FIG. 25  is another perspective view of the bone plate of  FIG. 23 ; 
           [0040]      FIG. 26  is a further perspective view of the bone plate of  FIG. 23 ; 
           [0041]      FIG. 27  is yet another perspective view of the bone plate of  FIG. 23 ; and 
           [0042]      FIG. 28  is a cross-sectional view of one type of partially threaded bone plate hole, according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0043]    For convenience, the same or equivalent elements in various embodiments of the bone plate illustrated in the drawings have been identified with the same reference numerals. Further, in the description that follows, any reference to either orientation or direction is intended primarily for the convenience of description and is not intended in any way to limit the scope of the present invention thereto. 
         [0044]    A first illustrative embodiment of a bone plate  10  is shown in  FIG. 1 . The bone plate  10  shown in  FIG. 1  is dimensioned and configured for internal fixation of the proximal portion of a fractured femur F. One of ordinary skill in the art will know and appreciate, however, that the principles of the present invention may be applied to bone plates for fixation of other bones of humans and/or animals, for example long bones, and for different parts of long bones (e.g., the proximal tibia, the distal femur, etc.). 
         [0045]    As shown in  FIGS. 1 and 2 , bone plate  10  has a longitudinal axis  15 , and includes an upper surface  20  and a lower surface  22 . Bone plate  10  may be constructed from biocompatible materials such as, for example, titanium, alloys of titanium, stainless steel, resorbable materials, and allograft, although one of ordinary skill in the art will know and appreciate that any biocompatible material may be used. As will be discussed in greater detail below and shown generally in  FIGS. 1 and 3 , bone plate  10  is configured to receive a plurality of bone anchors  110 ,  115 ,  120 ,  125 . Bone anchors  110 ,  115 ,  120  and  125  are shown in  FIG. 1  as bone screws, however other types of bone anchors known to one of ordinary skill in the art, such as blades, nails, pins, etc, may be used. The engagement of the bone plate  10  and screws  110 ,  115  may result in a truss formation  128  for effectively anchoring bone plate  10  to the proximal portion of a fractured femur, or other bone. Lower surface  22  may contact the bone F directly, as shown, or alternatively, may be held at a distance from the bone surface to facilitate increased flow of blood over the fracture zone. 
         [0046]    Now referring to  FIG. 3 , a cross-sectional view of bone plate  10  is shown. Bone plate  10  may include a first hole  24  and a second hole  28 . First hole  24  may define a central axis  26  along which the shaft portion of a first bone anchor would extend, and second hole  28  may define a central axis  30  along which the shaft of a second bone anchor would extend. First and second holes  24  and  28  may be configured such that central axes  26 ,  30  define a single plane and intersect in that plane at a point  32  below the lower surface  22 . The intersection of central axes  26 ,  30  may define an angle a, which is preferably an acute angle, and more preferably, between about 3° and about 60°. The central axis  26  of the first hole  24  may be substantially perpendicular to the lower surface  22  of the bone plate  10  or to the exterior surface of the bone F into which it is inserted. For example, central axis  26  may preferably be oriented at about a 95° with respect to the lower surface  22  of the bone plate  10 . The central axis  30  of the second hole  28  may be at an acute angle with respect to the lower surface  22  of the bone plate  10  or to the exterior of the bone F in which it is inserted. Bone plate  10  may also include at least two guide holes  18  as shown in  FIGS. 3 and 4  for receiving and guiding a wire. 
         [0047]    First and second holes  24 ,  28  may each be configured for engaging the head of a bone anchor. More preferably, first and second holes  24 ,  28  may be configured for fixing and locking with the bone anchor and more preferably for fixing the bone anchor in a fixed, predetermined orientation with respect to the lower surface  22  of the bone plate  10  or the exterior surface of the bone in to which it is inserted, for example, by threaded engagement, interference or press fitting, or any other form of joining the plate  10  with the screw heads known to one of ordinary skill in the art. The bone anchor is fixed to the plate such that its shaft or shank would extend along the central axes  26 ,  30  of the holes  24 ,  28  in the bone plate  10 . In the illustrative embodiment shown in  FIG. 3 , holes  24 ,  28  are threaded for respective engagement with bone anchors having threaded heads. 
         [0048]    An example of such a bone anchor is shown in  FIGS. 6 and 7 . Bone screw  100  defines a central axis  102 , a shaft in the form of a threaded shank  104  with tip  105 , and a threaded head  106 . Bone screw  100  may be constructed from, for example, titanium, alloys of titanium, stainless steel, resorbable materials such as polymers, allograft or other biocompatible materials known in the art. Bone screw  100  is preferably compatible with the bone plate  10  in terms of composition and strength. Bone screw  100  may be cannulated having a through bore or channel  107  extending from the upper surface  103  head  106  to the tip  105 , as seen in  FIG. 7 , for introducing instruments, for example, a guide wire into the fracture zone. 
         [0049]    Another bone anchor that may be in a fixed and locked engagement with first and second holes  24 ,  28  is the spiral blade  310  shown in  FIGS. 8 and 9 . Blade  310  defines a longitudinal axis  302  and has a proximal end  306 , a distal end  304  and an external surface  308  in the form of spiral flutes  307 , although other configurations are possible. The spiral blade  310  may be cannulated with a central channel  305 , as shown, or may be substantially solid. The proximal end  306  of blade  310  may be engaged in first or second hole  24 ,  28  by press-fitting or interference fitting, although the present invention is not limited to any specific type of junction between the bone plate and the bone anchors. 
         [0050]    Referring back to  FIG. 3 , threaded holes  24 ,  28  may be separately engaged by the threaded heads  106  of the bone screw  100  to form a locking threaded engagement between the plate and the threaded head  106 , thereby aligning shanks  104 , and central axis  102 , along central axes  26 ,  30 . The internal thread pattern of threaded holes  24 ,  28  and the matching thread pattern of threaded head  106  may preferably have a screw thread profile having a  60 ° thread angle, but other thread patterns are possible. The threaded engagement of the bone plate  10  and the threaded head  106  prevents movement of bone plate with respect to bone screws  100  engaged with threaded holes  24 ,  28 , and locks the angular position of central axes  102  with respect to the plate  10  and each other. With threaded shanks  104  of the bone screws anchored to the fractured bone and the threaded heads  106  lockingly engaged with the threaded holes  24 ,  28 , bone plate  10  is anchored to the bone. Depending upon the depth at which the threaded shank  104  is anchored into the bone, the lower surface  22  of bone plate  10  may directly contact the bone surface, or alternatively, may be affixed and spaced at a distance from the bone surface. In addition, wherein the shank  104  is of sufficient length so as to span across the gap of the fracture zone between the two fractured segments of bone F, either of the threaded holes  24 ,  28  and their central axes  26 ,  30  may align the shank  104  at such an angle with respect to the plate  10  so as to reduce the gap of the fracture zone upon locking of the threaded head  106  in the threaded hole  24 ,  28 . 
         [0051]    Referring again to  FIGS. 1 and 3 , because of the configuration of threaded holes  24 ,  28 , in which their central axes  26 ,  30  intersect at a point  32  below the lower surface  22  of bone plate  10 , the threaded engagement of bone screws  110 ,  115  with threaded holes  24 ,  28  form a truss  128  beneath the bone surface. The truss formation serves to increase the stability of the anchorage of bone plate  10  to the fractured bone. Additionally, the truss  128  serves to more evenly distribute loads and stresses throughout the bone plate  10  and the anchoring bone screws  110 ,  115 . These stresses would otherwise be concentrated in the engagement between the threaded heads  106  of the bone screws  110 ,  115  and the bone plate  10 . As shown in  FIG. 1 , with bone screws  110 ,  115  engaged with threaded holes  24 ,  28 , bone screws  110 ,  115  may contact one another at or near the point of intersection  32  below the bone surface F. More preferably, the tip  105  of the second bone screw  115  may contact the first bone screw  110  at the tip  105  of the first bone screw  110 , as generally shown in  FIG. 1  or at another location along the shank  104  of the first bone screw  110 , as shown in  FIG. 10 . Alternatively, the bone screws  110 ,  115  may not contact one another; however their central axes  102  may intersect to define a plane and thereby operably associate the bone screws  110 ,  115  with one another to more evenly distribute the loads and stresses experienced at the threaded screw head  106  to plate  10  interface. 
         [0052]    As is shown in  FIGS. 3 and 4 , threaded holes  24 ,  28  may be conically tapered in a direction from the upper surface  20  to the lower surface  22  of bone plate  10 . This tapering of the holes  24 ,  28  may facilitate alignment between the threads of holes  24 ,  28  and the threads on the heads  106  of bone screws  110 ,  115 . Alternatively, threaded holes  24 ,  28  may be substantially cylindrical, partially spherical or other shapes known in the art. As is more clearly shown in  FIG. 5 , the central axes  26 ,  30  of threaded holes  24 ,  28  may define a plane that intersects and lies at an angle β relative to a plane that substantially bisects the bone plate  10  and includes the longitudinal axis  15 . According to one preferred embodiment, the angle β may range from 0° to about 60°, or range to about 15°, or from about 3° to about 6°, however other angles are possible. 
         [0053]    As shown in  FIGS. 2 and 3 , bone plate  10  may include a third hole  34  defining a central axis  36  for engaging the head of a third bone anchor, shown for illustrative purposes in  FIGS. 1 and 5  as bone screw  120 . Third hole  34  may be similarly configured as threaded holes  26 ,  28  so as to include a thread for threaded engagement with the threaded head of bone screw  120 . Third threaded hole  34  may be conically tapered in the direction from the upper surface  20  to lower surface  22  of bone plate  10 , or alternatively, threaded hole  34  may be substantially cylindrical, partially spherical or other shapes known in the art. Third threaded hole  34  may be located between threaded holes  24 ,  28 . Referring specifically to  FIG. 5 , the central axis  36  of the third threaded hole  34  may intersect and lay at an angle δ relative to the plane defined by the central axes  26 ,  30  of the first and second threaded holes  24 ,  28 . Angle δ may range from about 0° to about 15°, or from about 5° to about 8°, although other angles are possible. Referring to  FIG. 2 , threaded holes  24 ,  28 ,  34  may be located on and spaced relative to one another along longitudinal axis  15 . 
         [0054]    The central axis  36  of the third hole  34  may be configured to intersect the axis  26  of the first hole  24 , and in addition or alternatively the central axis  36  may be configured to intersect the central axis  30  of the second bore hole  28 . The third bone anchor  120  may contact the first bone screw  110  at the tip  105  of the bone screw  110  or at another location along the shaft  104  of the first bone screw  110 . Alternatively, or in addition there to, the third screw  120  may contact the second bone screw  115  at its tip  105 , or at some other location along the shank  104  of the second bone screw  115 . In one embodiment, the third bone screw may contact both the first and second bone screw  110 ,  115 , along their respective lengths, and all three bone screws may contact each other at their respective tips  105 . 
         [0055]    Reference is now made to  FIG. 28 . In another embodiment, in lieu of, or in addition to, having any of the afore-described holes, the bone plate  10  may have a partially threaded hole  90 . The hole  90  may extend from the upper surface  20  to the lower surface  22  of the bone plate  10 . The diameters of the hole  90  at its uppermost surface and at its lower most surface may be equal or close to equal to each other. The hole may be widest at the uppermost surface  20  and lowermost surface  22  of the plate  10 . 
         [0056]    As shown in  28 , the hole  90  may have three regions: an upper region  92 , a middle region  94 , and a lower region  96 . The upper region  92  of the hole  90  may have an unthreaded inner surface  93  which, is preferably smooth, although texturing may be provided. In a preferred embodiment, the upper region  92  may have a curved inward taper, preferably concave, more preferably spherical, from the top surface of the plate  10  to where the upper region  92  of the hole  90  meets the middle region  94 . The upper region  92  of the hole  90  is preferably narrowest where it meets the middle region  94 . In a preferred embodiment, the upper region may comprise about 25% to about 35% of the thickness of the plate  10 . In a preferred embodiment, the diameter of the upper region  92 , at the region&#39;s broadest point, may be about 6 mm and, at the region&#39;s narrowest point, may be about 4 mm. 
         [0057]    The middle region  94  of the hole  90  may have a threaded inner surface  95 . The threaded inner surface  95  may, in a direction from the upper surface to the lower surface of the plate  10 , have a conical inward taper. In a preferred embodiment, the threaded inner surface  95  may taper at an angle α of approximately 5° to 15°, and preferably approximately 10°. The middle region  94  may be the narrowest region (i.e., smallest-diameter region) of the hole  90 . In a preferred embodiment, the middle region  94  may comprise about 40% to 50% of the thickness of the plate  10 . In a preferred embodiment, the diameter of the middle region  94  may vary only slightly (due to the relatively shallow conical taper) and may be about 4 mm. The diameter or taper of the middle region  94  may of course vary depending upon the size and/or taper of the screw. 
         [0058]    The lower region  96  of the hole  90  may have an unthreaded inner surface  97  which is preferably smooth, although texturing may be provided. In a preferred embodiment, the lower region  96  may, from where it meets the middle region  94  to the lower surface of the plate, have a conical outward taper. In a preferred embodiment, the lower region  96  may taper outwardly at an angle β of approximately 35° to 55°, and preferably approximately 45°. In a preferred embodiment, the lower region  96  may comprise about 20% to 35% of the thickness of the plate. In a preferred embodiment, the diameter of the lower region  96 , at the region&#39;s narrowest point, may be about 4 mm and, at the region&#39;s broadest point, may be about 6 mm. 
         [0059]    Different types of screws may be used with the hole  90 . One type of screw is a screw that has a conically-tapered threaded head. The external threads of the screw&#39;s head may mate with the internal threads  95  of the middle region  94  of the hole  90 . This threaded-head screw may be inserted at only one angle (with respect to the plate), which may be fixed by the threads  95  in the plate  10 . 
         [0060]    A second type of screw that may be used with the hole  90  is a screw with a threaded shaft, but with an unthreaded head. An unthreaded-head screw may be inserted into hole  90  at any one of a number of angles. The conical outward taper (shown at surface  97 ) of the lower region  96  of the hole  90  provides room for the screw shaft to be inserted at an angle with respect to the center of the hole  90 . Likewise, the curved inward taper of the upper region  92  of the hole  90  provides a seat (at surface  93 ) for the screw head to rest in when an unthreaded-head screw is inserted at an angle. A threaded-head screw may be used with a coaxial combination hole  90  in the same manner as the aforementioned unthreaded-head screw. 
         [0061]    Although virtually any type of bone plate may benefit from coaxial combination holes  90 , coaxial combination holes are particularly useful for pubic symphysis plates and other relatively small bone plates. 
         [0062]    Referring again to  FIG. 1 , bone plate  10  may include a first portion  6  that is substantially planar and a second portion  8  that is substantially curved for conforming to the head of a bone, such as the proximal portion of the femur F. Bone plate  10  may alternatively be configured as a straight plate, or additionally or alternatively configured to include a flared portion in addition to a shaft portion. The lower surface  22  of first portion  6  may engage the bone surface directly, in which instance first portion  6  may include a plurality of recesses  12  spaced about the longitudinal axis  15  for minimizing contact between the bone plate  10  and the bone surface to facilitate increased blood circulation over the fracture zone. Threaded holes  24 ,  28  are preferably located in the second portion  8  of bone plate  10  in which the second portion  8  conforms and follows the bone head. 
         [0063]    Bone plate  10  may be provided with any number of holes as may be suitable for a specific surgical application. For example, as shown in  FIG. 3 , bone plate  10  may include one or more combination holes  38 , which are substantially similar to the combination holes described in U.S. Patent Publication No. 2002/0183752 A1, incorporated herein by reference thereto. As shown in  FIG. 11A , each combination hole  38  includes a first, substantially circular portion  44 , and a second, elongated portion  46 . The circular portion  44  and the elongated portion  46  overlap one another, and are thus in communication with one another. The outer periphery of circular portion  44  defines a first center point  48 , and a diameter D. The outer periphery of elongated portion  46  defines a second center point  50 . The outer periphery of elongated portion  46  also defines a major axis  55  and a minor axis  57  substantially perpendicular to the major axis  55 . According to one embodiment of the invention, major axis  55  may be substantially parallel to longitudinal axis  15  of the bone plate  10 . In addition, major axis  55  may lay along longitudinal axis  15  with first and second center points  48 ,  50  located on longitudinal axis  15 , however other configurations are possible. Combination holes  38  may also be parallel but offset from longitudinal axis  15 , and combination holes may be alternatively offset with respect to longitudinal axis  15 . 
         [0064]    Elongated portion  46  may be configured and dimensioned to engage a substantially spherical screw-head of a bone screw (not shown). Additionally or alternatively, a conically shaped screw head, with or without threads, may engage the elongated portion  46 . As shown in  FIGS. 11A and 11B , elongated portion  46  may have a concave, substantially spherical portion or recess  60  that opens toward upper surface  20  of the bone plate  10 . When the shaft of a bone screw having a spherical head is located eccentrically in elongated portion  46  (towards the right in  FIG. 10 ), the spherical head may engage recess  60  and bias the bone plate  10  to provide compression of the bone fracture. In addition, a portion of the combination hole  38  may be concave along the lower surface  22  of the bone plate  10  to define a spherical recess  61 . 
         [0065]    Still referring to  FIGS. 11A and 11B , circular portion  44  may be configured and dimensioned to engage the threaded head of a bone screw (not shown). An internal thread  62  may be provided on circular portion  44 . Thread  62  may be disposed in a single plane or in several planes. The plane(s) may be parallel to upper surface  20  and/or lower surface  22 . According to the illustrative embodiment shown, thread  62  extends substantially over the entire thickness of the bone plate from the upper surface  20  to lower surface  22 . The internal thread  62  may be formed over an angle of approximately 190° to approximately 280°. Referring to  FIG. 1 , combination hole  38  is shown engaged with a bone screw  125 . 
         [0066]    Reference is now made to  FIG. 12A . In another embodiment, in lieu of, or in addition to, having combination hole(s)  38 , the bone plate  10  may have at least one of a different type of combination hole  80 . Each combination hole  80  may have two substantially circular portions  83  and  84 . The circular portions  83  and  84  may overlap one another, and be in communication with one another. 
         [0067]    An internal thread  87  may be provided on circular portion  83 . An internal thread  88  may be provided on circular portion  84 . Threads  87  and  88  may extend substantially over the entire thickness of the bone plate from the upper surface  20  to the lower surface  22 .  FIG. 12B  shows thread  88  of circular portion  84  extending the entire thickness of the bone plate. Threads  87  and  88  may be threaded in the same direction (e.g., requiring clockwise rotation for insertion of a screw with a threaded head) or in directions opposite from one another. Threads  87  and  88  may be disposed in a single plane or in several planes. The plane(s) of the threads may be parallel to upper surface  20  and/or lower surface  22  of bone plate  10 , or the plane formed by the threads may be angled with respect to the upper surface  20  and/or lower surface  22 . Each thread of threads  87  and  88  may be formed over an angle of approximately 190° to approximately 270°. Threads  87  and  88  may extend over the same angle or at angles different from one another. Threads  87  and  88  may have a conical inward taper. Combination hole(s)  80  may be positioned within the bone plate  10  in the same way that combination hole  38  may be positioned within the bone plate  10 , as described above, or in different arrangements. In addition, combination holes  80  may be used in bone plates that also include combination holes  38 , as well as any other hole described in the specification. 
         [0068]    Shown in  FIG. 13  is an alternative preferred embodiment, bone plate  910  configured substantially similar to bone plate  10 . The substantial difference between bone plate  910  and bone plate  10  is that bone plate  910  may include a hook portion  970 . The hook portion  970  may be attached, integral with or other wise disposed at end of the second portion  908 . As was previously described with regards to second portion  8  of bone plate  10 , second portion  908  may be similarly substantially curved for conforming to the head of the bone, F, for example the femoral head. The hook portion  970  includes a bone engaging edge  972  for digging or penetrating into bone tissue. More specifically, the bone plate  910  may be located along the proximal femur bone F such that second portion  908  may wrap around or conform to a portion of the greater trochanter and the hook portion  970  may engage a region of the piriformis. Bone engaging edge  972  may be configured for penetrating the bone surface to more effectively grip the bone F thereby permitting a surgeon to use bone plate  910  as a lever to resist the pull of muscle and tendons surrounding the broken segment of bone F and to properly align the bone F fragments. The depth at which the bone engaging edge  972  penetrates the bone F may be limited by the interference of the greater trochanter with the lower surface  922  of the bone plate  910 . Once the bone F is properly aligned, bone screws engaged with and fixedly aligned by holes  924 ,  928 ,  934  may be inserted in the bone so as to fix bone plate  910  with respect to bone F. 
         [0069]    Shown in  FIG. 13 , the hook portion  970  is configured so as to curve inward toward the first portion  906  of the bone plate  910  and terminating at a point beneath the lower surface  922  so as not to interfere with a bone anchor engaged with the first hole  924 . Shown in  FIG. 14 , the edge  972  may be preferably formed by two spaced apart talons  973 ,  974  although other configuration are possible to facilitate the secure engagement of hook  972  with the bone tissue. 
         [0070]    Shown in  FIGS. 15-27  are alternative embodiments of the bone plates configured for fixation of other long bones, for example, the tibia or humerus. Referring to  FIG. 15-17 , shown is an alternative embodiment, bone plate  410  which includes upper surface  420 , a lower surface  422 , a first section  401 , which has a first longitudinal axis  402 , and a second section  403 , which has a second longitudinal axis  404 . As with bone plate  10 , the lower surface  422  of bone plate  410  may contact the surface of the bone directly, or alternatively, at least a portion of lower surface  422  may be held at a distance from the bone surface to facilitate increased flow of blood over the fracture zone. As seen in  FIG. 15 , recesses  412  may be provided along the lower surface  422  to facilitate the flow of blood over the fracture zone. Referring now to  FIG. 18 , the bone plate  410  may further include a transition section  405  connecting the first section  401  to the second section  403  in a manner such that the first longitudinal axis  402  and the second longitudinal axis  404  define an angle λ in between. The first, second, and transition sections  401 ,  403 ,  405  may be formed from a single piece of material, however other configurations are possible, for example, the pieces may be welded or otherwise joined together. In addition, first, second and transition sections  401 ,  403 ,  405  may have substantially the same width throughout the bone plate, and may be substantially parallelogram in shape. However, other configurations are possible, for example, at least one of the sections  401 ,  403 ,  405  may be flared or generally polygonal in shape. 
         [0071]    Referring to  FIG. 17 , the bone plate may include at least a first hole  424  and a second hole  428  having central axes  426 ,  428  respectively. First and second holes  424 ,  428  are configured in a substantially similar manner to holes  24 ,  28  of bone plate  10 , such that they are capable of engaging a bone anchor, for example, the bone screw  100 , the spiral blade  310  as previously described, or other types of bone anchors previously mentioned. It should be understood that first and second holes  424 ,  428  may be configured for engaging the head of a bone anchor by threaded engagement, interference or press fitting, or any other form of joining the plate with the anchor heads known to one of ordinary skill in the art. As shown, the first and second holes  424 ,  428  are preferably configured so as to form respective locking threaded engagement with bone screws  510 ,  515 , similar to bone screw  100 , having threaded heads  506  (not shown), shafts  504  and tips  505 . The first and second holes  424 ,  428  may include an internal thread and have a conical taper from the upper surface  420  to the lower surface  422 . The locked engagement fixes bone screws  510 ,  515  to the plate  410  such that shafts  504  extend along the central axes  426 ,  430  of the holes  424 ,  428  in the bone plate  410 . Additionally, the first and second holes  424 ,  428  are preferably configured such that the central axes  426 ,  430  intersect at a point  432  below the lower surface  422  of the bone plate  410 . The threaded engagement of bone screws  510 ,  515  with the threaded first and second holes  424 ,  428  may form a truss  528  beneath the bone surface, in a manner as previously described with respect to bone plate  10 . The bone screw  510  may be substantially perpendicular to the lower surface  422  of the bone plate  410  or the exterior of the surface of the bone in which it is inserted. The bone screw  515  may be at an acute angle with respect to the lower surface of the bone plate or the exterior of the bone in which it is inserted. Screw  515  may contact bone screw  510  at the tip  105  of the bone screw  510 , or anywhere along the shaft  104  of bone screw  510 . According to one illustrative embodiment, the angle formed by the intersection of central axes  426 ,  430  may range from between about 30° to about 60°, although other angles are possible. 
         [0072]    The first and second holes  424 ,  428  may be located in the same section of the bone plate  410 , or alternatively the first hole  424  may be located in a section different from that of the second hole  428 . Where the first and second hole  424 ,  428  are in the same section of the bone plate  410 , the plane defined by the intersection of  426 ,  430  may be coplanar with a plane that bisects that same section of the bone plate  410  where the first and second holes  424 ,  428  are located. Alternatively, the plane defined by the intersection of central axes  426 ,  430  may be at an angle with respect to the plane that bisects bone plate  410  (not shown). The angle formed by the bisecting plane and the plane defined by intersecting central axes  426 ,  430  may range from about 0° to about 60°, or range to about 15°, or range from about 3° to about 6°. 
         [0073]    A further embodiment, bone plate  610  shown in  FIGS. 18-22 , comprises first and second holes  624 ,  628 , shown in  FIG. 21 , having first and second central axes  626 ,  630  intersecting at  632 . A still further embodiment, bone plate  810 , shown in  FIGS. 25-29  comprises first and second holes  824 ,  828 , shown in  FIG. 25 , having central axes  826 ,  830  intersecting  832 . It is to be understood that first and second holes  624 ,  628  of bone plate  610  and first and second holes  824 ,  828  of bone plate  810  may be variably configurable as first and second holes  424 ,  428  of bone plate  410  described above. More specifically, the engagement of bone anchors with the plate  610  and/or  810  may fix the bone anchors at a predetermined angle to form, respectively, truss  728 , shown in  FIG. 21  and truss  1128 , shown in  FIG. 26 , beneath the bone surface as presently described with respect to bone plates  10  and  410 . The first and second bone screws may contact one another along their respective shafts or tips. In addition, bone plates  610  and  810  may selectively be anchored to bone such that their lower surfaces  622 ,  822  either contact the bone surface directly, with or without recesses  612 ,  812  for facilitating blood circulation over the fracture zone; or bone plates  610 ,  810  may be spaced from the bone surface at a relative distance. 
         [0074]      FIGS. 15-27  show bone plates  410 ,  610 ,  810  and the respective connections of the first sections  401 ,  601 ,  801  and second sections  403 ,  603 ,  803  by the transition section  405 ,  605 ,  805  in various configurations; however, even other configurations are possible. Referring again to  FIG. 16 , the included angle λ formed between the first and second central axes  402 ,  404  may be obtuse, ranging from about an angle of 195° to about 175°, or 120° to 160°, or preferably angle λ measures about 153°. Alternatively the included angle may be substantially acute, ranging from an angle of about 15° to about 85°, preferably about 22°. Also, the angle λ may be a right angle, in which the second section  403  is substantially perpendicular to the first section  401 . 
         [0075]    As shown in  FIGS. 15-27 , the first and second sections of bone plates  410 ,  610 ,  810  may have different lengths, e.g., the first section may be longer than the second section. The configurations are substantially similar to those shown and described in U.S. Patent Publication 2002/0183752 A1, the entire content of which is incorporated by reference thereto. Referring specifically to  FIGS. 20 and 25 , bone plates  610 ,  810  may, respectively, be substantially L-shaped or T-shaped. As shown in  FIG. 19 , the first section  601  may be located in a plane different from that of the second section  603 . For instance, transition section  605  may be curved such that the lower surface  622  of the first section  601  is located in a first plane and the lower surface  622  of the second section  603  is located in a second plane different from the first plane. Alternatively or in addition thereto, the transition section  605  may be twisted so that the lower surface  622  of one side of the longitudinal axis  602 ,  604  is in a different from that of the lower surface  622  of the other side of the longitudinal axis  602 ,  604 . This may be beneficial where the bone plates  410 ,  610 ,  810  have to be located over a curved portion of a bone, such as the medial and lateral condyles of the proximal tibia. 
         [0076]    Referring now to  FIG. 23 , shown is another bone plate  810  in which the transition section  805  may define a third longitudinal axis  806  and may be configured so as to define a first included angle λ 1  with the first longitudinal axis  802  of the first section  801  and a second included angle λ 2  with the second longitudinal axis  804  of the second section  803 . The transition section  805 , may be bent, curved or twisted as previously described, or additionally, the transition section  805  may be twisted such that the upper surface  820  is substantially S-shaped. The first and second sections  401 ,  403 ;  601 ,  603 ;  801 ,  803  of bone plates  410 ,  610 ,  810  may also be twisted or bent to conform to the bone surface. For example, referring now to  FIG. 20 , shown is a cross-section view of the second section  603  of bone plate  610  in which the lower surface  622  may be bent or curved along the second longitudinal axis  604 , so as to define a radius of curvature R. In addition, a portion of the first section  601  may be twisted about the first longitudinal axis  602 . 
         [0077]    The bone plates  410 ,  610 ,  810  may also be provided with at least a third hole defining a third central axis, in which the third hole may be variably configurable as the first and second holes  424 ,  428  previously described. The third hole may be engageable with the head or end portion of a bone anchor, for example bone screw  100  having a shaft  104  and tip  105 . Specifically referring to  FIGS. 18 and 19 , an illustrative example, bone plate  610  includes third hole  634  having central axis  636 . Third hole  634  may be configured for threaded locked engagement with a bone screw  100  so as to align the shaft  104  of bone screw  100  along the third central axis  636 . The third central axis  636  of the third hole  634  may be disposed at such an angle so as to intersect with at least one of the first and second central axes  626 ,  630  of the first and second holes  624 ,  628 . The third central axis  636  may be disposed at angle with respect to the plane formed by first and second central axes  626 ,  630 . 
         [0078]    Shown in the  FIGS. 21 and 22  is bone plate  610  engaged with bone screws  710 ,  715 ,  720  respectively engaged with first, second and third holes  624 ,  628 ,  634 . Bone screws  710 ,  715  are threadedly engaged with first and second holes  624 ,  628  to form truss  728  for rigidly anchoring the bone plate  610  to the fractured bone. The third bone screw  720 , may be in threaded locked engagement with the bone plate  610  such that at least a portion of the shaft  104  of the third bone screw  720 , preferably the tip  105 , may touch or nearly touch at least one of the shafts of the first or second bone screws  710 ,  715  so as to further reinforce the truss  728  and the anchorage of bone plate  610 . The third hole  634  may be located in the same section of the bone plate as either of the first and second holes  624 ,  628 . Alternatively, the third hole  634  may be located in a section different from that or those of either of the first and second holes  624 ,  628 . For example, as shown in  FIG. 21 , the third hole  634  is located in the transition section  605  with second hole  628 . First hole  624  is located in the second section  603  of the bone plate  610 . 
         [0079]    As shown in  FIGS. 15-27 , bone plates  410 ,  610  and  810  may be provided with any number of holes as may be suitable for a specific surgical application. Any of these additional holes may be configured in a manner similar to and fully variable as first and second holes  424 ,  428  of bone plate  410 , as previously described. 
         [0080]    Referring now to  FIGS. 21 and 22 , the second section  603  of bone plate  610  may include additional holes  640 ,  644 ,  648  having central axes  642 ,  646 ,  650 . As shown in  FIG. 21 , these additional holes may be configured for locked threaded engagement with heads  706  of bone screws  725 ,  730 ,  735  having shafts  704 , in which the shafts  704  align with central axes  642 ,  646 ,  650 . The central axes  642 ,  646 ,  650  may be disposed at such angles with respect to the first and second central axes  626 ,  630 , that the shafts of bone screws  725 ,  730 ,  735  either touch, almost touch or are substantially parallel to bone screws  710 ,  715 , which are shown engaged with first and second holes  624 ,  628 . Additional holes similarly configured as  640 ,  644 ,  648  may be disposed in any of the first sections  401 ,  601 ,  801 , second sections  403 ,  603 ,  803 , or transition sections  405 ,  605 ,  805  of bone plates  410 ,  610 ,  810  as is necessary for the given surgical application. Shown in the illustrative embodiment of  FIG. 21 , transition section  605  includes hole  652  engaged with bone screw  740 . Alternatively, the screw holes in the bone plate  610 , can be configured such that a bone anchor, such as for example, conically threaded screw, can engage hole  624  and a second bone screw can engage hole  634  such that the screws contact or nearly contact to form a first truss structure. Alternatively or in addition thereto a third bone screw can engage hole  628  and a fourth bone screw can engage hole  648  such that the third and fourth screws contact or nearly contact to form a second truss structure. Alternatively, first bone screw and third bone screw may contact or nearly contact to form the first truss structure and second bone screw and fourth bone screw may contact or nearly contact to form the second truss structure. Alternatively or in addition, a fifth bone anchor may engage bone screw hole  652  and a sixth bone screw may engage hole  644 . The fifth and sixth bone screws may contact or nearly contact to form yet a third truss structure. 
         [0081]    First, second and third truss structures may be formed by any number of combinations of bone anchors in any number of configurations. Additionally, bone plate  610  may be provided with additional holes as is necessary to form the desired number of truss structures. Moreover, the first, second, third and any additional truss structures may or may not contact or nearly contact one or more of the other truss structures. Preferably, the second, third and additional truss structures may be angled so as to intersect a plane defined by the first truss structure. 
         [0082]    Another example is shown in the embodiment of bone plate  410 . In  FIG. 17 , shown are holes  440 ,  444  disposed in the first section  401  spaced relative to the first and second holes  424 ,  428  located in the second section  403  of bone plate  410 . Holes  440 ,  444  may be preferably configured for, respectively, threaded locked engagement with the threaded heads  506  (not shown) of bone anchors  525 ,  530  such that the shafts  104  may diverge from one another and diverge from the shafts  504  of bone fasteners  510 ,  515  engaged in first and second holes  424 ,  428 . Another illustrative example is shown as the sixth embodiment, bone plate  810  in  FIG. 25 . First hole  824  is disposed in the second section  803 , second hole  828  is disposed in the first section  801 . Referring to  FIGS. 25 and 26 , the third hole  834  is located in the transition section  805  and is configured such that the shaft  1104  of bone screw  1120  engaged with third hole  834 , would touch or nearly touch one of the shafts  1104  of bone screws  1110 ,  1115  engaged in first and second holes  824 ,  828 . Additional holes  840 ,  844  are disposed in the second section  803  and are configured so as to engage bone screws  1125 ,  1130  in such a manner that the shafts  1104  would align in a direction toward the bone screws  1110 ,  1115  engaged in first and second holes  824 ,  828  so as to almost touch. 
         [0083]    Bone plates  410 ,  610 ,  810  may yet further include additional holes, threaded or unthreaded, for receiving additional bone anchors for anchoring the bone plates  410 ,  610 ,  810  to bone. For example, bone plates  410 ,  610 ,  810  may include a plurality of combination holes  438 ,  638 ,  838 , which are similar to the combination holes  38  described above in reference to  FIGS. 11A and 11B . The combination holes  438 ,  638 ,  838  may all preferably be located in the first section  401 ,  601 ,  801  of the bone plates  410 ,  610 ,  810 . Additionally, bone plates  410 ,  610 ,  810  may include one or more holes configured for receiving a guide wire or other instrument, for example, hole  72 , as shown in  FIG. 2  for receiving an instrument for applying compression to the fracture, or for example, as shown in  FIG. 20 , second section  603  includes a plurality of holes  618  configured for receiving a guide wire or other instrument. 
         [0084]    The bone plates  10 ,  910 ,  410 ,  610 , and  810  may vary in both length and width, but generally the length exceeds the width so as to define a generally longitudinal member. The length of the bone plates may range from about 50 mm. to about 500 mm. Bone plate  10  may preferably range in length from about 135 mm. to about 435 mm. Bone plate  910  may preferably range in length from about 145 mm. to about 480 mm. Bone plate  410  may preferably range in length from about 75 mm. to about 235 mm. Bone plate  610  may preferably range in length from about 81 mm. to about 240 mm. Bone plate  810  may preferably range in length from about 105 mm to about 350 mm. Any section of bone plates  10 ,  910 ,  410 ,  610  and  810  may also vary in width from about 5 mm. to about 10 mm. to about 18 mm. Where one section of the bone plate is perpendicular to the other, the widest part of the bone plate may be as much as 35 mm. The thickness of the plates may vary as well from approximately 3 mm to about 5 mm. In addition the bone plates may vary in thickness in along its length. For example, shown in  FIG. 1  portion  6  of bone plate  10  generally has a tapered portion. First sections  406 ,  606  and  806  may also generally have a tapered portion as well. All the bone plates discussed may have a tapered portion elsewhere throughout the bone plate or alternatively, the plate thickness may vary in cross-section. 
         [0085]    While preferred embodiments and features of the present invention have been disclosed herein, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art. It is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of such claims and that the claims not be limited to or by such preferred embodiments or features.

Technology Classification (CPC): 0