Abstract:
A fixation device serves in facilitating reduction and repair of a fractured humerus. The fixation device includes a bone plate adapted to overlie and contact portions of a proximal humerus and a humeral shaft. The bone plate includes at least a body portion overlying the humeral shaft, and an end portion overlying a portion of the proximal humerus. The end portion can facilitate attachment of the bone plate to the lesser tuberosity of the proximal humerus.

Description:
[0001]    The present application claims the benefit of provisional Application No, 61/449,012, filed Mar. 3, 2011; which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to a fixation device used to facilitate reduction and repair of a fractured bone. More particularly, the present invention relates to a bone plate for creating a mechanically stronger connection between the bone plate and portions of a fractured humerus including the proximal humerus and the humeral shaft. More specifically, the present invention relates to a bone plate configured to provide optimal angles for bone screws received therethrough to decrease the incidence of penetration of the bone screws through the articular surface of the humeral head. 
         [0004]    2. Description of the Prior Art 
         [0005]    Current state of the art in surgical fracture fixation of the proximal humerus requires the application of a bone plate to the greater tuberosity of the proximal humerus. To attach the bone plate to the proximal humerus, bone screws (threadably or non-threadably engaging the bone plate) are inserted through the bone plate into the proximal humerus. In attaching the bone plate to the proximal humerus, the bone screws are ultimately received under the surface of the humeral head. 
         [0006]    The bone screws used to attach the bone plate to the proximal humerus will likely be disposed at a significantly perpendicular angle with respect to the articular surface of the humeral head. This attachment orientation provides insufficient mechanical strength to maintain rigid attachment of the bone plate to the proximal humerus when subjected to joint reaction forces. As such, there remains a significant incidence of loss of fracture reduction and fracture fixation. In order to maximize stability of the connection, it is necessary to utilize long bone screws, so as to maximize the purchase thereof. However, given the significantly perpendicular angle of the bone screws relative to the articular surface, if there is any collapse or subsidence of the humeral head relative to the bone plate, the tips of the bone screws will penetrate the articular surface. Accordingly, there also remains a significant incidence of joint penetration. 
         [0007]    Therefore, there is a need for a fixation device and method of use associated therewith that provides more optimal screw angles with respect to the articular surface of the humeral head and a mechanically stronger connection between the bone plate and the humerus. Such a fixation device can insure that bone screws are disposed at varying angles that are more tangential to the articular surface to prevent loss of fracture fixation and fracture reduction, and/or prevent penetration of the bone screws through the articular surface of the humeral head. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention in a preferred embodiment contemplates a fixation device for facilitating reductions and repair of a fractured humerus, the fixation device including a bone plate adapted to overlie and contact portions of a proximal humerus and a humeral shaft, the bone plate having a body portion, a neck portion, and a first end portion, the body portion including a first end, a second end opposite the first end, a longitudinal axis extending between the first and second ends, a plurality of bone screw receiving apertures adapted to overlie the humeral shaft, and a first contact surface adapted to contact the exterior surface of the humeral shaft, the longitudinal axis of the body portion being adapted to be substantially aligned with the humeral shaft when the bone plate is attached to the humerus, the neck portion extending from the body portion, the neck portion being adapted to bridge the biceps groove of the proximal humerus when the bone plate is attached to the humerus, the first end portion being contiguous to the neck portion, the first end portion including a second contact surface adapted to contact the exterior surface of the lesser tuberosity of the proximal humerus, and at least two bone screw receiving apertures adapted to overlie the lesser tuberosity, the at least two bone screw receiving apertures each including an axis, the axes of the at least two bone receiving apertures being oriented away from the articular surface of the proximal humerus when the bone plate is attached to the humerus; at least a first set of bone screws, a first bone screw of the first set of bone screws being received through a first of the plurality of bone screw receiving apertures and into the humeral shaft, and a second bone screw of the first set of bone screws being received through a second of the plurality of bone screw receiving apertures and into the humeral shaft, the first and second bone screws of the first set of bone screws facilitating attached of the bone portion to the humeral shaft; and at least a second set of bone screws, each bone screw of the at least a second set of bone screws having a longitudinal axis, a first bone screw of the second set of bone screws being received through a first of the at least two bone screw receiving apertures and into the lessor tuberosity, a second bone screw of the second set of bone screws being received through a second of the at least two bone screw receiving apertures and into the lessor tuberosity, the longitudinal axes of the first and second bone screws of the second set of bone screws being aligned with the axes of the first and second bone screw receiving apertures and being oriented away from the articular surface of the proximal humerus when the bone plate is attached to the humerus. 
         [0009]    The present invention in a further preferred embodiment contemplates A fixation device for facilitating reductions and repair of a fractured humerus, the fixation device including a bone plate adapted to overlie and contact portions of a proximal humerus and a humeral shaft, the bone plate having a body portion, a neck portion, and a first end portion, the body portion including a first end, a second end opposite the first end, a longitudinal axis extending between the first and second ends, a plurality of bone screw receiving apertures adapted to overlie the humeral shaft, and a first contact surface adjacent the second end and adapted to contact the exterior surface of the humeral shaft, the longitudinal axis of the body portion being adapted to be substantially aligned with the humeral shaft when the bone plate is attached to the humerus, and the plurality of bone screw receiving apertures being positioned from adjacent a midpoint of and the second end of the body portion, the neck portion extending from between the first and second ends of the body portion, the neck portion being adapted to bridge the biceps groove of the proximal humerus when the bone plate is attached to the humerus, the neck portion terminating in the first end portion, the first end portion including a second contact surface adapted to contact the exterior surface of the lesser tuberosity of the proximal humerus, and at least two bone screw receiving apertures adapted to overlie the lesser tuberosity, the at least two bone screw receiving apertures each including an axis, the axes of the at least two bone receiving apertures being oriented away from the articular surface of the proximal humerus when the bone plate is attached to the humerus; at least a first set of bone screws, a first bone screw of the first set of bone screws being received through a first of the plurality of bone screw receiving apertures and into the humeral shaft, and a second bone screw of the first set of bone screws being received through a second of the plurality of bone screw receiving apertures and into the humeral shaft, the first and second bone screws of the first set of bone screws facilitating attached of the bone portion to the humeral shaft; and at least a second set of bone screws, each bone screw of the at least a second set of bone screws having a longitudinal axis, a first bone screw of the second set of bone screws being received through a first of the at least two bone screw receiving apertures and into the lessor tuberosity, a second bone screw of the second set of bone screws being received through a second of the at least two bone screw receiving apertures and into the lessor tuberosity, the longitudinal axes of the first and second bone screws of the second set of bone screws being aligned with the axes of the first and second bone screw receiving apertures and being oriented away from the articular surface of the proximal humerus when the bone plate is attached to the humerus. 
         [0010]    It is understood that both the foregoing general description and the following detailed description are exemplary and exemplary only, and are not restrictive of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention. Together with the description, they serve to explain the objects, advantages and principles of the invention. In the drawings: 
           [0012]      FIG. 1  is a perspective view of a left proximal humerus; 
           [0013]      FIG. 2  is a top view of the left proximal humerus depicted in  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective view of a bone plate of a first embodiment of a fixation device according to the present invention positioned with respect to the proximal humerus; 
           [0015]      FIG. 3A  is a perspective view of the fixation device of  FIG. 3  depicting the placement of bone screws used in the fixation device; 
           [0016]      FIG. 4  is a perspective view of a bone plate of a second embodiment of a fixation device according to the present invention positioned with respect to the proximal humerus; 
           [0017]      FIG. 4A  is a perspective view of the fixation device of  FIG. 4  depicting the placement of bone screws used in the fixation device; 
           [0018]      FIG. 5  is a perspective view of a bone plate of a third embodiment of a fixation device according to the present invention positioned with respect to the proximal humerus; 
           [0019]      FIG. 5A  is a perspective view of the fixation device of  FIG. 5  depicting the placement of bone screws used in the fixation device; and 
           [0020]      FIG. 6  is a top cross-sectional view of the fixation device depicted in  FIG. 5A  taken through the greater tuberosity, the lesser tuberosity, and a portion of the fixation device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    The following description is intended to be representative only and not limiting, and many variations can be anticipated according to these teachings. Reference will now be made in detail to the preferred embodiments of this invention, examples of which are illustrated in the accompanying drawings. 
         [0022]      FIGS. 1 and 2  depict the portions of a left proximal humerus generally indicated by the numeral  10 . Proximal humerus  10  is joined to humeral shaft  12  ( FIG. 1 ), and includes greater tuberosity  14 , lesser tuberosity  16 , biceps groove  18 , humeral head  20 , and an articular surface  22  of humeral head  20 . Biceps groove  18  is disposed between greater tuberosity  14  and lesser tuberosity  16 . Thus, as depicted in  FIG. 2 , greater tuberosity  14  is disposed laterally of biceps groove  18 , and lesser tuberosity  16  is disposed medially of biceps groove  18 . Furthermore, in  FIGS. 3-5A , lesser tuberosity  16  is partially covered by the fixation devices of the present invention. Thus, the lead line associated with numeral  16  in  FIGS. 3-5A  points to proximal humerus  10  adjacent where fixation devices of the present invention are positioned. 
         [0023]    As discussed above, to facilitate fracture fixation and fracture reduction, a bone plate typically has been attached to greater tuberosity  14 . However, the placement of bone screws by the bone plate attached solely to greater tuberosity  14  is less than optimal. The bone screws will likely be disposed at a significantly perpendicular angle with respect to articular surface  22  of humeral head  20 , and thus, cause a significant incidence of penetration of articular surface  22 . 
         [0024]    A first embodiment of a fixation device according to the present invention is generally indicated by the numeral  30  in  FIGS. 3 and 3A . Fixation device  30  includes a “dogleg-shaped” bone plate  31  and various bone screws inserted therethrough and into bone. 
         [0025]    Bone plate  31  has a body portion  32 , a neck portion  34 , and an end portion  36 . Body portion  32  includes apertures  40  spaced therealong, and is attached to humeral shaft  12  and portions of proximal humerus  10  using bone screws  41  ( FIG. 3A ) inserted through apertures  40  and into the bone. As depicted in  FIGS. 3 and 3A , neck portion  34  extends from body portion  32  over biceps groove  18 , and terminates at end portion  36 . End portion  36  includes apertures  42  spaced apart thereon, and is attached to lesser tuberosity  16  using bone screws  43  ( FIG. 3A ) inserted through apertures  42  and into proximal humerus  10 . Apertures  40  and  42  extend between an upper surface  44  and a lower surface (not shown) of bone plate  31 . The lower surface of bone plate  31  can be contoured according to the surfaces of proximal humerus  10  to provide a flush interface therebetween. 
         [0026]    Apertures  42  each include an axis substantially perpendicular to at least one of the upper and lower surfaces of bone plate  31  adjacent thereto, and the longitudinal axes of bone screws  43  received therein are ultimately aligned with the axes of apertures  42 . The angles of the longitudinal axis of apertures  42  serve to orient bone screws  43  in positions that inhibit the incidence of penetration thereof through articular surface  22 . For example, the orientation angles afforded by apertures  42  serve to position bone screws  43  in at least substantially tangential orientations with respect to articular surface  22  of humeral head  20 . Accordingly, the axes of apertures  42  and the longitudinal axes of bone screws  43  received therein can be oriented away from and avoid intersection with articular surface  22 , thereby decreasing the incidence of penetration of bone screws  43  through articular surface  22 , while also preventing a loss of fracture fixation and fracture reduction. 
         [0027]    A second embodiment of a fixation device according to the present invention is generally indicated by the numeral  50  in  FIGS. 4 and 4   k  Fixation device  50  includes an “h-shaped” bone plate  51  and various screws inserted therethrough and into bone. 
         [0028]    Bone plate  51  has a body portion  52 , a neck portion  54 , a first end portion  56 , and a second end portion  58 . Body portion  52  includes apertures  60  spaced therealong, and is attached to humeral shaft  12  and portions of proximal humerus  10  using bone screws  61  ( FIG. 4A ) inserted through apertures  60  and into the bone. As depicted in  FIGS. 4 and 4A , first end portion  56  is contiguous with body portion  52 , and includes apertures  62  spaced apart thereon. First end portion  56  is attached to greater tuberosity  14  using bone screws  63  ( FIG. 4A ) inserted through apertures  62  and into proximal humerus  10 . As depicted in  FIGS. 4 and 4A , neck portion  54  extends from between body portion  52  and first end portion  56  over biceps groove  18 , and terminates at second end portion  58 . Second end portion  58  includes apertures  64  spaced apart thereon, and is attached to lesser tuberosity  16  using bone screws  65  ( FIG. 4A ) inserted through apertures  64  and into proximal humerus  10 . Apertures  60 ,  62 , and  64  extend between an upper surface  66  and a lower surface (not shown) of bone plate  51 . The lower surface of bone plate  51  can be contoured according to the surfaces of proximal humerus  10  to provide a flush interface therebetween. 
         [0029]    Apertures  62  each include an axis substantially perpendicular to at least one of the upper and lower surfaces of bone plate  51  adjacent thereto, and the longitudinal axes of bone screws  63  received therein are ultimately aligned with the axes of apertures  62 . As discussed below, use of second end portion  58  to facilitate attachment of bone plate  51  to proximal humerus  10  affords use of shorter bone screws  63  in apertures  62  than those typically used to secure attachment to greater tuberosity  14 . 
         [0030]    Like apertures  62 , apertures  64  each include an axis substantially perpendicular to at least one of the upper and lower surfaces of bone plate  51  adjacent thereto, and the longitudinal axes of bone screws  65  received therein are ultimately aligned with the axes of apertures  64 . The angles of the axes of apertures  64  serve to orient bone screws  65  in positions that inhibit the incidence of penetration thereof through articular surface  22 . For example, the orientation angles afforded by apertures  64  serve to position bone screws  65  in at least substantially tangential orientations with respect to articular surface  22  of humeral head  20 . As such, the axes of apertures  64  and the longitudinal axes of bone screws  65  received therein can be oriented away from and avoid intersection with articular surface  22 . Accordingly, such an orientation allows bone screws  63  inserted into lesser tuberosity  16  to share (with bone screws  63 ) in resisting the joint forces applied in a direction perpendicular to articular surface  22 , thereby decreasing the incidence of penetration of bone screws  63  through articular surface  22 , while also increasing the overall mechanical strength of the connection, preventing a loss of fracture fixation and fracture reduction. 
         [0031]    Because bone plate  51  is attached using (1) first end portion  56  to greater tuberosity  14 , and (2) using second end portion  58  to lesser tuberosity  16 , bone screws  63  used with apertures  62  can be shorter than those typically used to attach a bone plate solely to greater tuberosity  14 . Thus, given that shorter bone screws  63  are used, the incidence of shorter bone screws  63  (inserted through greater tuberosity  14 ) penetrating articular surface  22  of humeral head  20  can be significantly lessened. That is, even if the orientations of the axes of apertures  62  and the longitudinal axes of bone screws  63  received therein intersect articular surface  22 , the lengths of bone screws  63  received in apertures  62  do not afford penetration of articular surface  22 . 
         [0032]    A third embodiment of a fixation device according to the present invention is generally indicated by the numeral  70  in  FIGS. 5 ,  5 A, and  6 . Fixation device  70  includes a “y-shaped” bone plate  71  and various screws inserted therethrough and into bone. 
         [0033]    Bone plate  71  has a body portion  72 , a neck portion  74 , and an end portion  76 . As depicted in  FIGS. 5 and 5A , body portion  72  extends along greater tuberosity  14  and humeral shaft  12 . Body portion  72  includes first apertures  80  and second apertures  82  formed therein. First apertures  80  are spaced apart from one another at one end of body portion  72  (ultimately adjacent greater tuberosity  14 ), and second apertures  82  are spaced along body portion  72  from adjacent first apertures  80  to the other end of body portion  72  (ultimately adjacent humeral shaft  12 ). 
         [0034]    Furthermore, as depicted in  FIG. 5 , neck portion  74  extends from body portion  72  over biceps groove  18 , and terminates at end portion  76 . Neck portion  74  can be formed integrally with body portion  72  (as depicted in  FIG. 5 ), or neck portion  74  can be formed separately from body portion  72 . When body portion  72  and neck portion  74  are formed separately, body portion  72  and neck portion  74  can be attached to one another before or during surgery. Furthermore, neck portion  74  can be positioned to overlap body portion  72 , and then body portion  72  and neck portion  74  can be attached to one another; or body portion  72  can be positioned to overlap neck portion  74 , and then body portion  72  and neck portion  74  can be attached to one another. 
         [0035]    When formed separately from one another, body portion  72  and neck portion  74  can be attached to one another using one or more fasteners such as screws (not shown). Furthermore, to facilitate attachment of one another, body portion  72  and neck portion  74  can each include one or more corresponding apertures (not shown) formed therein and configured to receive the associated fastener or fasteners. Accordingly, during surgery, body portion  72 , for example, can be attached to proximal humerus  10  first, and then neck portion can  74  can be attached to proximal humerus  10  and body portion  72 , or neck portion  74  can attached to proximal humerus  10  first, and then body portion  72  can be attached to proximal humerus  10  and neck portion  74 . 
         [0036]    End portion  76  includes apertures  84  spaced apart from one another thereon (ultimately adjacent lesser tuberosity  16 ). Apertures  80 ,  82 , and  84  extend between an upper surface  86  and a lower surface (not shown) of the bone plate  71 . The lower surface of bone plate  71  can be contoured according to the surfaces of proximal humerus  10  to provide a flush interface therebetween. 
         [0037]    First apertures  80  are configured to receive bone screws  81  ( FIGS. 5A and 6 ) and second apertures  82  are configured to receive bone screws  83  ( FIG. 5A ) to facilitate attachment of body portion  72  to greater tuberosity  14  and humeral shaft  12 , respectively. Furthermore, apertures  84  are configured to receive bone screws  85  ( FIG. 5A and 6 ) therethrough to attach end portion  76  to lesser tuberosity  16 . 
         [0038]    Apertures  80  each include an axis substantially perpendicular to at least one of upper and lower surfaces of bone plate  71  adjacent thereto, and the longitudinal axes of bone screws  81  received therein are ultimately aligned with the axes of apertures  80 . As discussed below, use of end portion  76  to facilitate attachment of bone plate  71  to proximal humerus  10  affords use of shorter bone screws  81  in apertures  80  than those typically used to secure attachment to greater tuberosity  14 . 
         [0039]    Like apertures  80 , apertures  84  each include an axis substantially perpendicular to at least one of the upper and lower surfaces of bone plate  71  adjacent thereto, and the longitudinal axes of bone screws  85  received therein are ultimately aligned with the axes of apertures  84 . The angles of the axes of apertures  84  serve to orient bone screws  85  in positions that inhibit the incidence of penetration thereof through articular surface  22 . For example, the orientation angles afforded by apertures  84  serve to position bone screws  85  in at least substantially tangential orientations with respect to articular surface  22  of humeral head  20 . As such, the axes of apertures  84  and the longitudinal axes of bone screws  85  received therein can be oriented away from and avoid intersection with articular surface  22 , and are substantially perpendicular to the longitudinal axes of bone screws  81 . Accordingly, such an orientation allows bone screws  85  to share (with bone screws  81 ) in resisting the joint forces applied in a direction perpendicular to articular surface  22 , thereby decreasing the incidence of penetration of bone screws  85  through articular surface  22 , while also increasing the overall mechanical strength of the connection, preventing a loss of fracture fixation and fracture reduction. Furthermore, as discussed below, the right angle construct formed by the substantial perpendicularity between the longitudinal axes of bone screws  81  and  85  provides significant mechanical advantages. 
         [0040]    Because the bone plate  71  is attached using (1) apertures  80  and bone screws  81  to greater tuberosity  14 , and (2) using apertures  84  (of end portion  76 ) and bone screws  85  to lesser tuberosity  16 , bone screws  81  can be shorter than those typically used to attach a bone plate solely to greater tuberosity  14 . Thus, given that bone screws  81  are shorter than those typically used, the incidence of bone screws  81  (inserted through greater tuberosity  14 ) penetrating articular surface  22  of humeral head  20  can be significantly lessoned. That is, even if the orientations of the axes of apertures  80  and the longitudinal axes of bone screws  81  received therein intersect articular surface  22 , the lengths of bone screws  81  received in apertures  80  do not afford penetration of articular surface  22 . 
         [0041]    The right angle construct formed by the substantial perpendicularity between the longitudinal axes of bone screws  81  and  85  provides significant mechanical advantages that reinforce the connection between proximal humerus  10  and bone plate  71 . That is, in addition to affording shorter bone screws  81 , the substantial perpendicularity between the longitudinal axes of bone screws  81  and  85  serves in stabilizing proximal humerus  10 . 
         [0042]    To further stabilize proximal humerus  10 , bone screws  81  and  85  can be configured to engage one another within proximal humerus  10 . For example, bone screws  85  inserted into lesser tuberosity  16  (via end portion  76 ) can engage bone screws  81  inserted into greater tuberosity  14  (via body portion  72 ). Bone screws  85  can impinge on bone screws  81 , or bone screw  81  can include apertures (not shown) for receiving bone screws  85 . Either way, the engagement of bone screws  81  and  85  forms a lattice structure within proximal humerus  10 . In doing so, bone screws  81  and  85  strengthen proximal humerus  10 , and further prevent a loss of fracture fixation and fracture reduction thereof. The structure and formation of lattice structures (such as that form by bone screws  81  and  85 ) is described in pending U.S. application Ser. Nos. 11/050,304 and 13/253,564, which are herein incorporated by reference. 
         [0043]    Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. Accordingly, it is intended that the specification and examples be considered as exemplary only.