Abstract:
A bone implant, particularly but not necessarily, for fixing bones of the foot is provided having body in the form of a crescent or arced shaped wedge, or a wedge in the shape of a crescent or arc. The crescent shaped wedge has bone screw bores that are each configured to hold a bone screw at a particular angle for receipt in a bone, eliminating the need to also use a plate. The crescent shape provides a graft area that allows introduction and retention of bone graft material to promote bone fusion. One or both tapered sides of the crescent shaped wedge may also have teeth, serrations or the like.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This U.S. non-provisional patent application is a continuation-in-part of co-pending patent application Ser. No. 14/616,239 filed Feb. 6, 2015 titled “Foot Implant For Bone Fixation”, which claimed the benefit of and/or priority under 35 U.S.C. §119(e) to U.S. provisional patent application Ser. No. 61/936,644 filed Feb. 6, 2014 titled “Foot Implant For Bone Fixation,” the entire contents of each of which is specifically incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to implants for fixation of human bones, and particularly, to implants for fixation of bones of the foot. More particularly, the present invention relates to implants for internal fixation of calcaneus, tarsal, and metatarsal bones of the foot. 
         [0004]    2. Background Information 
         [0005]    There are many reasons why surgeries are performed on the bones of the foot. Some foot surgeries such as osteotomies are performed to correct angular deformities. Other foot surgeries are performed to mend a fracture or to re-align or reposition bones of the foot. In these surgical procedures and others, two bone portions must be joined or otherwise connected to each other so as to be fixed in a desired position and, eventually fuse. This may be accomplished by a foot bone implant. 
         [0006]    A foot bone implant in the shape of a wedge is typically inserted between the two bone portions or into the joint. The wedge, however, has to be retained in its insertion position by a plate placed over the joint. The plate can cause irritation to the adjacent anatomy as well as to the patient. 
         [0007]    It is therefore evident from the above that there is a need for a foot bone implant in the shape of a wedge that overcomes the deficiencies of the prior art. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is a wedge-shaped bone implant, system and method of use particularly, but not necessarily, for fixing bones of the foot. The wedge-shaped bone implant has bone screw bores that are each configured to hold a bone screw at a particular angle for receipt in a bone portion, thereby eliminating the need to also use a plate. 
         [0009]    In one form, the wedge-shaped bone implant is moreover configured to receive a plate that aids in preventing a bone screw from backing out of its implant bore. The plate may be fastened to the wedge-shaped bone implant by one or more fastening screws. In this form, the top of the wedge-shaped implant has a recess that at least partially surrounds openings of the two implant bores. The recess is configured to receive the plate such that the plate at least partially obstructs the ability of a bone screw head within the implant bore to back out. Moreover, in this form, one or more of the threaded fastening screw bores for the fastening screws of the cover, may be used for engagement with an insertion instrument. 
         [0010]    In another form, the wedge-shaped bone implant lacks a configuration on the top and thus does not accept a plate for covering the bone screws. In this case, a threaded bore may be provided for engagement with an insertion instrument instead of a threaded plate fastening screw bore. 
         [0011]    One implant bore extends from the top of the implant body to one tapered side of the implant body, while the other implant bore extends from the top of the implant body to the other tapered side of the implant body. When installed, one bone screw projects from one tapered side of the shaped implant body, while the other bone screw extends from the other tapered side of the implant body. One bone screw thereby projects into one foot bone portion, while the other bone screw projects into the other bone screw portion, or different foot bones. 
         [0012]    The bone implant can include an opening that extends through the implant body from one tapered side thereof to the other tapered side thereof. This opening allows the introduction and retention of bone graft material in order to promote bone fusion (i.e. a graft window). One tapered side of the body may also have teeth, serrations or the like that at least partially surround the graft window. The other tapered side may likewise also have teeth, serrations or the like that at least partially surround the graft window. 
         [0013]    In one form, the implant body includes a through hole, bore, slot or the like in the distal aspect of the implant body. This allows for the insertion of a metallic component (e.g. titanium or tantalum) to allow for the visibility of the extent of the implant body in radiography, x-ray, or the like. 
         [0014]    The present bone implant is thus characterized by an implant body in the general shape of a wedge, (e.g. as may be defined in solid geometry, as a right triangular prism with a rounded top, including a right oblique wedge in which the top edge is symmetrically shortened, causing the end triangles to slant obliquely) thus forming a right oblique wedge. The first bone screw bore extends from the rounded top to one slanted side of the wedge, while the second bone screw bore extends from the rounded top to the other slanted side of the wedge opposite the one side. 
         [0015]    In one form, the outer configuration of the general wedge shape of the present foot bone implant may be modified from a traditional right oblique wedge shape to other wedge shapes or shapes incorporating a wedge structure. One such wedge modification provides a crescent or arced shaped wedge or a wedge in the shape of a crescent or arc. The crescent shaped wedge may include a threaded bore for engagement with an insertion instrument instead of a threaded plate fastening screw bore. The crescent shape also defines a bone graft opening or area that allows the introduction and retention of bone graft material in order to promote bone fusion. One tapered side of the implant body may also have teeth, serrations or the like that at least partially surround the graft opening. The other tapered side may likewise also have teeth, serrations or the like that at least partially surround the graft opening. The implant body may include a through hole, bore, slot or the like in the distal aspect of the implant body allowing for the insertion of a metallic component (e.g. titanium or tantalum) to allow for the visibility of the extent of the implant body in radiography, x-ray, or the like. 
         [0016]    According to one method of use, the bone implant is placed into a bone joint to correct a deformity and provide fixation for fusion. The present bone implant permits the inclusion of bone screws to self-retain the wedge within the joint as well as providing stability for fusion. This is accomplished without the need for an additional plate. 
         [0017]    According to another method of use, bone graft material is placed in the graft window, opening or area of the bone implant. The bone implant with bone graft material is then placed into a bone joint, bone osteotomy site, bone fracture or the like and provide fixation for fusion. The bone implant with bone graft material permits the inclusion of bone screws to self-retain the wedge within the joint as well as providing stability for fusion. Again, this is accomplished without the need for an additional plate. 
         [0018]    Further aspects of the present invention will become apparent from consideration of the drawings and the following description of preferred forms of the invention. A person skilled in the art will realize that other forms of the invention are possible and that the details of the invention can be modified in a number of respects without departing from the inventive concept. The following drawings and description are to be regarded as illustrative in nature and not restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The features of the invention will be better understood by reference to the accompanying drawings which illustrate forms of the invention, wherein: 
           [0020]      FIG. 1  is an isometric view of a wedge-shaped bone implant fashioned in accordance with the principles of the present invention; 
           [0021]      FIG. 2  is an isometric view of the wedge-shaped bone implant of  FIG. 1  having a bone screw situated in the bone implant and another bone screw ready for insertion into the bone implant; 
           [0022]      FIG. 3  is an isometric view of the wedge-shaped bone implant of  FIG. 1  having two bone screws situated therein along with a screw retention plate, forming a bone implant system; 
           [0023]      FIG. 4  is an end view of the bone implant system of  FIG. 3 ; 
           [0024]      FIG. 5  is a top view of the bone implant system of  FIG. 3 ; 
           [0025]      FIG. 6  is an isometric view of the bone screw retention cover/plate of the bone implant system of  FIG. 3 ; 
           [0026]      FIG. 7  is an isometric view of another wedge-shaped bone implant fashioned in accordance with the principles of the present invention; 
           [0027]      FIG. 8  is a side view of the bone implant of  FIG. 7 ; 
           [0028]      FIG. 9  is an isometric view of the bone implant of  FIG. 8  having two bone screws situated therein; 
           [0029]      FIG. 10  is a side view of the bone implant with bone screws of  FIG. 9 ; 
           [0030]      FIG. 11  is an isometric view of another wedge-shaped bone implant fashioned in accordance with the principles of the present invention; 
           [0031]      FIG. 12  is an isometric view of the wedge-shaped bone implant of  FIG. 11  having a bone screw situated in the bone implant and another bone screw ready for insertion into the bone implant; 
           [0032]      FIG. 13  is an isometric view of the wedge-shaped bone implant of  FIG. 11  having two bone screws situated therein, forming another foot bone implant system; 
           [0033]      FIG. 14  is a top view of the bone implant system of  FIG. 13 ; 
           [0034]      FIG. 15  is an end view of the bone implant system of  FIG. 13 ; 
           [0035]      FIG. 16  is an isometric view of another wedge-shaped bone implant fashioned in accordance with the principles of the present invention; 
           [0036]      FIG. 17  is an isometric view of the wedge-shaped bone implant of  FIG. 16  having a bone screw situated in the bone implant; 
           [0037]      FIG. 18  is a top view of the wedge-shaped bone implant of  FIG. 16  having two bone screws situated in the bone implant; 
           [0038]      FIG. 19  is an top end view of the wedge-shaped bone implant of  FIG. 16  having two bone screws situated in the bone implant; 
           [0039]      FIG. 20  is a side view of the wedge-shaped bone implant of  FIG. 16  having two bone screws situated in the bone implant; 
           [0040]      FIG. 21  is a bottom end view of the wedge-shaped bone implant of  FIG. 16  having two bone screws situated in the bone implant; and 
           [0041]      FIG. 22  is a view of bones of a left foot with the wedge-shaped bone implant of  FIG. 16  implanted in a fracture or osteotomy cut of the first metatarsal of the foot. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    Referring to  FIGS. 1-6  and, in particular  FIG. 1 , there is depicted a bone implant generally designated  10 . The bone implant  10  is fashioned from a known biocompatible implant material and is used for aiding or providing internal fixation of calcaneus, tarsal, and metatarsal bones of the foot in cases such as, but not limited to, filling an osteotomy or expanding and correcting an angular deformity in the foot. The bone implant  10  may be used with other bones of the body such as the hand. However, the bone implant  10  will be described within this detailed description of the invention for us with bones of the foot and thus as a foot bone implant  10 . The foot bone implant  10  has a generally wedge-shaped body  12  as wedges are defined in solid geometry and explained in the Summary of the Invention. As such, the body  12  has a generally rounded top  13 , a generally planar first side  14 , a generally planar second side  15  (see  FIG. 4 ), a generally planar first end  16 , a generally planar second end  17  (see  FIG. 4 ), and a generally pointed bottom  18 . The first and second sides  14  and  15  each slope inwardly from the top  13  to the bottom  18 . The dimensions and angles of the foot bone implant  10  may be changed as desired in order to accommodate varying anatomies, purpose, and desired outcome. It should also be appreciated that the foot bone implant  10  and/or its principles are applicable to other bones of the body such as, but not limited to, the bones of the hand. 
         [0043]    The body  12  has two bores  20 ,  21  each of which are dimensioned to receive a bone screw  90  such that the head of the bone screw is held by the body  12  and a portion of the tip and shank of the bone screw  90  extend from the body (see e.g.,  FIGS. 3-5 ) for receipt in a foot bone. The first bone screw bore  20  extends between the top  13  and the first side  14  such that the tip of a bone screw  90  extends from the first side  14  at an angle thereof. As particularly seen in  FIG. 5 , the opening of the first bone screw bore  20  on the top  13  of the body  12  is situated proximate to and on the edge between the top  13  and the second side  15  creating the angled bone screw bore  20 . The second bone screw bore  21  extends between the top  13  and the second side  15  such that the tip of a bone screw  90  extends from the second side  15  at an angle thereof. As again particularly seen in  FIG. 5 , the opening of the second bone screw bore  21  on the top  13  of the body  12  is situated proximate to and on the edge between the top  13  and the first side  14  creating the angled second bone screw bore  21 . Both bone screw bore openings on the top  13  of the body  12  are sized and configured to capture and retain the head of a bone screw. Moreover, both bone screw bore openings on the top  13  are configured such that the heads of the bone screws are countersunk relative to the surface of the top  13 . 
         [0044]    A configured recess, channel, groove, depression, or the like  23  is provided in the surface of the top  13 . The recess  23  is in communication with the bone screw bore openings on the top  13 . Additionally, a threaded bore  24  is provided in the body  12  within the recess  23  of the top  13 , the threaded bore  24  configured to receive a threaded screw or fastener  92 . The recess  23  is further configured to receive a cover or plate  30 . As seen in  FIG. 6 , the cover  30 , made from a biocompatible material, has hole  31  and first and second wings  32 ,  33 . The cover  30  is shaped such that it fits into the recess  23 . Preferably, but not necessarily, the cover  30  is shaped in similar manner to the recess  23 . The cover  30  is received in the recess  23  such that the hole  31  is aligned with the threaded bore  24  in the top  13  of the body  12 , with the first wing  32  extending over at least a part of the opening of first bone screw bore  20  and the second wing  33  extending over at least a part of the opening of the second bone screw bore  21 .  FIGS. 3 and 5  show the cover  30  mounted to the body  12  by the threaded screw  92 . Two bone screws  90  are also situated in the body  12 . The first wing  32  extends over or covers a portion of the bone screw head of the bone screw  90  that is in the first bone screw bore  20 . The second wing  33  extends over or covers a portion of the bone screw head of the bone screw  90  that is in the second bone screw bore  21 . The first and/or second wing may be shaped to extend over more of the bone screw head than shown. Because the wings are over the bone screw heads, this prevents the bone screw from backing out of the bone screw bore. 
         [0045]    Referring to  FIGS. 7-10 , there is depicted a foot bone implant, generally designated  10   a , being a variation of the foot bone implant  10 . As such, the foot bone implant  10   a  is thus fashioned in a generally like manner to the foot bone implant  10 , with the like features and/or components denoted by the addition of the letter “a” to the feature and/or component of the foot bone implant  10 . Because these features and/or components are the same, they will not be discussed in detail. Reference should therefore be made to the foot bone implant  10  for details. 
         [0046]    As best seen in  FIGS. 7 and 9 , the foot bone implant body  12   a  has an opening  60  that extends from the one tapered or slanted side  14   a  to the other tapered or slanted side  15   a . While the opening  60  is shown as rectangular, it should be appreciated that the opening  60  may be configured as desired. The opening  60  is used to receive and hold bone graft material. As such, the opening  60  may be considered a bone graft window or simply a graft window. The bone graft material may be of any kind. Moreover, the graft window may comprise two or more openings that each extend from the one tapered or slanted side  14   a  to the other tapered or slanted side  15   a . These graft openings can be shaped as desired. 
         [0047]    As seen in  FIGS. 9 and 10 , the two bone screws  90  are shown situated in the body  12   a  such as they would appear when implanted. The bone screw cover  30  is within the top recess  23   a  and fastened to the body  12   a  via the fastener  92 . As per the foot bone implant  10 , portions of the cover  30  extend over the bone screw heads in order to prevent the bone screws from backing out. 
         [0048]    In addition to the bone graft window  60 , the body  12   a  has features for aiding in and/or promoting fusion between two foot bones or foot bone portions. These features also aid in keeping the body  12   a  in place. Particularly, a portion of the one tapered or slanted side  14   a  has teeth, serrations or the like  62 , while a portion of the other tapered or slanted side  15   a  likewise has teeth, serrations or the like  64 . The teeth  62  surround the graft window  60  or at least are present about the top and sides of the graft window  60  in the slanted side  14   a . Likewise, the teeth  64  surround the graft window  60  or at least are present about the top and sides of the graft window  60  in the slanted side  15   a . The upper portions of the slanted sides  14   a  and  15   a  proximate the top  13   a  and the lower portions of the slanted sides  14   a ,  15   a  proximate the bottom  18   a  preferably, but not necessarily, lack teeth, serrations, or the like. 
         [0049]    Referring to  FIGS. 11-15 , there is depicted a foot bone implant, generally designated  10   b , being a variation of the foot bone implants  10  and/or  10   a . As such, the foot bone implant  10   b  is thus fashioned in a generally like manner to the foot bone implants  10 ,  10   a , with the like features and/or components denoted by the addition of the letter “b” to the feature and/or component of the foot bone implants  10 ,  10   a . Because these features and/or components are the same, they will not be discussed in detail. Reference should therefore be made to the foot bone implants  10 ,  10   a  for details. 
         [0050]    As best seen in  FIGS. 11-13 , the foot bone implant body  12   b  has an opening  60   b  that extends from the one tapered or slanted side  14   b  to the other tapered or slanted side  15   b . While the opening  60   b  is shown as rectangular, it should be appreciated that the opening  60   b  may be configured as desired. The opening  60   b  is used to receive and hold bone graft material. As such, the opening  60   b  may be considered a bone graft window or simply a graft window. The bone graft material may be of any kind. Moreover, the graft window may comprise two or more openings that each extend from the one tapered or slanted side  14   b  to the other tapered or slanted side  15   b . These graft openings can be shaped as desired. 
         [0051]    As seen in  FIGS. 13-15 , the two bone screws  90  are shown situated in the body  12   b  such as they would appear when implanted. In addition to the bone graft window  60   b , the body  12   b  has features for aiding in and/or promoting fusion between two foot bones or foot bone portions. These features also aid in keeping the body  12   b  in place. Particularly, at least a portion or more of the one tapered or slanted side  14   b  has teeth, serrations or the like  62   b , while at least a portion or more of the other tapered or slanted side  15   b  likewise has teeth, serrations or the like  64   b . The teeth  62   b  surround the graft window  60   b  or at least are present about the top and sides of the graft window  60   b  in the slanted side  14   b . Likewise, the teeth  64   b  surround the graft window  60   b  or at least are present about the top and sides of the graft window  60   b  in the slanted side  15   b . The upper portions of the slanted sides  14   b  and  15   b  proximate the top  13   b  and the lower portions of the slanted sides  14   b ,  15   b  proximate the bottom  18   b  preferably, but not necessarily, lack teeth, serrations, or the like. It should be appreciated that any pattern of teeth, direction of teeth, and/or dimensions of teeth may be used. 
         [0052]    As best seen in  FIGS. 11-14 , the top  13   b  of the implant body  12   b  lacks a configuration on the top for a cover and thus does not accept a plate for covering the bone screws like foot implants  10  and  10   a . In this case, a threaded bore  24   b  may be provided for engagement with an insertion instrument (not shown) instead of a threaded plate fastening screw bore. 
         [0053]    As best seen in  FIGS. 11-12 , the implant body  12   b  includes a through hole, bore, slot or the like  73   b  in the distal aspect  18   b  of the implant body  12   b . This allows for the insertion of a metallic component such as titanium or tantalum (not shown) to allow for the visibility of the extent of the implant body in radiography, x-ray, or the like. 
         [0054]    Referring to  FIGS. 16-21 , there is depicted another foot bone implant, generally designated  10   c , being a variation or modification from the traditional right oblique wedge shape foot bone implants  10 ,  10   a , and  10   b . However, the foot bone implant  10   c  is fashioned in a generally like manner to the foot bone implants  10 ,  10   a , and  10   b , and thus like features and/or components are denoted by the addition of the letter “c” to the feature and/or component of the foot bone implants  10 ,  10   a ,  10   b . Because these features and/or components are at least generally the same, some will not necessarily be discussed in detail. Reference should therefore be made to the foot bone implants  10 ,  10   a , and  10   b  for details if necessary. The foot bone implant  10   c  is fashioned from a known biocompatible implant material and is used for aiding or providing internal fixation of calcaneus, tarsal, and metatarsal bones of the foot in cases such as, but not limited to, filling an osteotomy or expanding and correcting an angular deformity in the foot. Other uses are contemplated. 
         [0055]    The foot bone implant  10   c  has a body  12   c  generally in the form of a crescent or arced shaped wedge or a wedge in the shape of a crescent or arc. The crescent shaped wedge body  12   c  has a generally curved top  13   c , a generally planar first side  14   c , a generally planar second side  15   c , a generally curved first end  16   c , a generally curved second end  17   c , and a curved bottom  18   c  forming first and second legs  19   a ,  19   b . The first and second sides  14   c  and  15   c  each slope, slant or incline inwardly from the curved top  13   c  to the curved bottom  18   c . The body  12   c  further includes a threaded bore  24   c  for engagement with an insertion instrument (not shown) instead of a threaded plate fastening screw bore. The dimensions and angles of the foot bone implant  10   c  may be changed as desired in order to accommodate varying anatomies, purpose, and desired outcome. It should also be appreciated that the foot bone implant  10   c  and/or its principles are applicable to other bones of the body such as, but not limited to, bones of the hand. 
         [0056]    The body  12   c  has two bores  20   c ,  21   c  each of which are dimensioned to receive a bone screw  90  such that the head of the bone screw is held by the body  12   c  and a portion of the tip and shank of the bone screw  90  extend from the body for receipt in a bone. The first bone screw bore  20   c  extends between the curved top  13   c  and the first side  14   c  such that the tip of a bone screw  90  extends from the first side  14   c  at an angle thereof. As particularly seen in  FIG. 19 , the opening of the first bone screw bore  20   c  on the curved top  13   c  of the body  12   c  is situated proximate to and between the curved top  13   c  and the second side  15   c  creating the angled bone screw bore  20   c . The second bone screw bore  21   c  extends between the curved top  13   c  and the second side  15   c  such that the tip of a bone screw  90  extends from the second side  15   c  at an angle thereof. As again particularly seen in  FIG. 19 , the opening of the second bone screw bore  21   c  on the curved top  13   c  of the body  12   c  is situated proximate to and between the curved top  13   c  and the first side  14   c  creating the angled second bone screw bore  21   c . Both bone screw bore openings on the curved top  13   c  of the body  12   c  are sized and configured to capture and retain the head of the bone screw  90 . Moreover, both bone screw bore openings  20   c ,  21   c  on the curved top  13   c  are configured such that the heads of the bone screws  90  are countersunk relative to the surface of the curved top  13   c.    
         [0057]    As best seen in  FIGS. 16-18 , because the bone implant body  12   c  is crescent shaped, the bottom  18   c  between the first and second legs  19   a ,  19   b  defines an opening that may be used to receive and hold bone graft material. As such, the crescent shaped opening defined by the curved bottom  18   c  may be considered a bone graft opening or area. Since the curved bottom  18   c  faces into the bone when implanted (see  FIG. 22 ), the bone graft material is held within the bone draft opening. The bone graft material may be of any kind. 
         [0058]    As seen in  FIGS. 18-21 , the two bone screws  90  are shown situated in the body  12   c  such as they would appear when implanted. In addition to the bone graft opening defined between the first and second legs  19   a ,  19   b  of the curved bottom  18   c , the body  12   c  has features for aiding in and/or promoting fusion between two bones or bone portions. These features also aid in keeping the body  12   c  in place. Particularly, at least a portion or more of the slanted side  14   c  has teeth, serrations or the like  62   c , while at least a portion or more of the other slanted side  15   c  likewise has teeth, serrations or the like  64   c . The teeth  62   c  surround the graft opening. Likewise, the teeth  64   c  surround the graft opening. The upper portions of the slanted sides  14   c  and  15   c  proximate the curved top  13   c  preferably, but not necessarily, lack teeth, serrations, or the like. It should be appreciated that any pattern of teeth, direction of teeth, and/or dimensions of teeth may be used. 
         [0059]    While not shown in the figures, the implant body  12   c  may include a through hole, bore, slot or the like in the distal aspect of the implant body  12   c . This allows for the insertion of a metallic component such as titanium or tantalum (not shown) to allow for the visibility of the extent of the implant body in radiography, x-ray, or the like. 
         [0060]    Referring to  FIG. 22  bones of a left human foot, generally designated  100 , are depicted. The first metatarsal  101  of the foot  100  has had a fracture or osteotomy cut  102  into which the bone implant  10   c  (with or without bone graft material) has been implanted. 
         [0061]    It should be appreciated that although the present bone fixation device has been shown in the figures and described above in particularity with respect to bones of the foot, such is applicable to bones of the hand; those bones being very similar in anatomy. It should also be appreciated that dimensions of the body and its features and/or components can be changed as desired.