Abstract:
Various embodiments of the present invention relate to a bone plate apparatus and methods for using the bone plate apparatus. More particularly, in one embodiment the bone plate apparatus and/or method may be used in connection with a laminoplasty procedure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No. 60/512,653, filed Oct. 20, 2003 
     
    
     FIELD OF THE INVENTION  
       [0002]     Various embodiments of the present invention relate to a bone plate apparatus and methods for using the bone plate apparatus.  
         [0003]     More particularly, in one embodiment the bone plate apparatus and/or method may be used in connection with a laminoplasty procedure.  
       BACKGROUND OF THE INVENTION  
       [0004]     Examples of various patent documents in the laminoplasty area include the following:  
         [0005]     U.S. Patent Publication No. 20040030388 in the name of Null et al. relates to laminoplasty devices and methods. More particularly, laminoplasty plates are engageable to at least one portion of a divided lamina to maintain a desired spacing relative to the spinal canal. The laminoplasty plates include a spacer portion having a first end and a second end that spans a gap formed by at least one of a divided lamina portion. The laminoplasty plates can include a lamina engagement portion at one end for engagement with the divided lamina portion.  
         [0006]     U.S. Pat. No. 6,080,157 to Cathro et al. relates to a device to stabilize the lamina. More particularly, a device for dynamically stabilizing the lamina after a laminoplasty includes a spacer which is shaped to engage between the severed edges of the lamina. The device also includes a retainer attached to the spacer which is adapted to maintain the spacer in an operative position. A method of dynamically stabilizing the lamina after a laminoplasty is also provided, which includes the steps of positioning the spacer between the severed edges of the lamina, and positioning the retainer to maintain the spacer in the operative position.  
         [0007]     U.S. Patent Publication No. 20030125738 in the name of Khanna relates to a laminoplasty with laminar stabilization method and system. More particularly, fixation devices and methods for stabilization of the lamina after laminoplasty are described. The device comprises a plate with several holes that receive bone fasteners. The plate is curved at the ends to contour to the vertebral structure and has appendages to engage the displaced lamina in a fixed position. Alternatively, the plate has a bone fusion spacer in the middle to engage and fuse the lamina in the displaced position. Several methods of dynamically stabilizing the lamina after either the open door, double door or expansive laminoplasty technique are provided.  
         [0008]     U.S. Pat. No. 6,712,852 to Chung et al. relates to a laminoplasty cage. More particularly, a medical implant device for use in spinal surgery, and more preferably for use in laminoplasty surgery is provided. The implant is a cage-like member having a generally hollow, elongate body with open ends. The implant is formed from a generally hollow, elongate body having four sides: opposed cephalad and caudal sides, and opposed posterior and anterior sides adjacent to the cephalad and caudal sides. The four sides extend along a longitudinal axis, and define an inner lumen extending between opposed first and second open ends.  
         [0009]     U.S. Pat. No. 6,635,087 to Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for use in the spinal column are disclosed. The implants comprise a bone allograft coupled with a non-allogenic plate. The plate has ends that fasten to opposing spine segments, and an intermediate portion that engages the allograft using deformable fingers, or with a hollow portion sized to receive and hold part of the allograft, or with fixed tabs. Methods of using the implants are also disclosed.  
         [0010]     U.S. Patent Publication No. 20030045935 in the name of Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for maintaining a distance between cut spinal bones are disclosed. The implants are made of metal, polymer or bone allograft, and have ends angled with respect to each other to conform to the cut bone ends. The implants have hollow regions for packing osteogenic material. The implant ends have surface projections to reduce slippage. Implants made of bone allograft also have ends made of demineralized bone to speed fusion between spine and implant. Methods of using the implants are also disclosed.  
         [0011]     U.S. Patent Publication No. 20020120335 in the name of Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for maintaining a distance between cut spinal bones are disclosed. The implants are made of metal, polymer or bone allograft having ends configured to conform to the cut bone ends. The implants have hollow regions for packing osteogenic material. The implant ends have surface projections to reduce slippage. Implants made of bone allograft also have spine contacting ends made of demineralized bone to speed fusion of spine and implant; they may also have bone flaps to fix the implant to the spine. Methods of using the implants are also disclosed.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  shows a perspective view of one embodiment of a bone plate apparatus according to the present invention;  
         [0013]      FIGS. 2A and 2B  show exploded perspective views of the bone plate apparatus of  FIG. 1  ( FIG. 2A  shows the bone plate apparatus from one angle and  FIG. 2B  shows the bone plate apparatus from another angle);  
         [0014]      FIGS. 3A, 3B  and  3 C show, respectively, a plan view, a side elevational view and a front view of the bone plate apparatus of  FIG. 1 ;  
         [0015]      FIGS. 4A, 4B  and  4 C show, respectively, a plan view, a side elevational view and a front view of a bone plate apparatus according to another embodiment of the present invention;  
         [0016]      FIGS. 5A, 5B  and  5 C show, respectively, a plan view, a side elevational view and a front view of a bone plate apparatus according to another embodiment of the present invention;  
         [0017]      FIG. 6  shows a perspective view of a bone plate apparatus according to an embodiment of the present invention and an insertion tool associated therewith according to an embodiment of the present invention;  
         [0018]      FIG. 7  shows a cut-away view of a bone plate apparatus according to an embodiment of the present invention; and  
         [0019]      FIG. 8  shows another perspective view of two bone plate apparatus according to embodiments of the present invention. 
     
    
       [0020]     Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention are intended to be illustrative, and not restrictive. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.  
         [0022]     Referring now to  FIG. 1  (as well as  FIGS. 2A and 2B , showing exploded perspective views of the bone plate apparatus of  FIG. 1 ), one embodiment of a bone plate apparatus according to the present invention is shown. As seen in these Figs., Bone Plate  101  may be attached to bone using Bone Screws  103   a ,  103   b  and  103   c . In one example (which example is intended to be illustrative and not restrictive), Bone Plate  101  may have a length between 20 mm and 30 mm (e.g., Bone Plate  101  may be provided in a number of distinct lengths). In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws  103   a ,  103   b  and  103   c  may be a self-tapping bone screw. In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws  103   a ,  103   b  and  103   c  may have a diameter selected from the group including (but not limited to) 1.5 mm, 2.0 mm and 2.7 mm. In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws  103   a ,  103   b  and  103   c  may have a length from 4 mm to 8 mm, in 0.1 mm increments.  
         [0023]     Further, Locking Plate  105  (which may itself be held in place by Fastener  107  (e.g., a machine screw)) may be used to help prevent screw back-out ( FIGS. 2A and 2B  show use of Locking Plate  105  and Fastener  107  most clearly).  
         [0024]     Further still, Slot  109  (which may have distinct holding positions or detents (as shown in these Figs.), and/or which may not have such detents in order to allow essentially free positioning anywhere within the slot) may be provided to aid in adjustment to an individual patient&#39;s anatomy.  
         [0025]     Further still, one or more protrusions (or “teeth”) may be provided to aid in maintaining position during and/or after implantation (a number of such teeth are shown but not separately numbered in these Figs.).  
         [0026]     Further still, the bottom profile may be streamlined as shown in these Figs. (e.g., in order to reduce the penetration inside the spine).  
         [0027]     Referring now to  FIGS. 3A, 3B  and  3 C, a plan view, a side elevational view and a front view of the bone plate apparatus of  FIG. 1  are shown. Of note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.  
         [0028]     Referring now to  FIGS. 4A, 4B  and  4 C, a plan view, a side elevational view and a front view of a bone plate apparatus according to an embodiment of the present invention are shown. Of note, these Figs. depict the bone plate apparatus without showing the bone screws. Of further note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.  
         [0029]     Referring now to  FIGS. 5A, 5B  and  5 C, a plan view, a side elevational view and a front view of a bone plate apparatus according to an embodiment of the present invention are shown. Of note, these Figs. depict the bone plate apparatus without showing the bone screws. Of further note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.  
         [0030]     Referring now to one example use of a bone plate apparatus according to the present invention (which example is intended to be illustrative and not restrictive), it is noted that under this example an “open door laminoplasty” (wherein the vertebrae are made to swing open like a door) may be simplified and/or stability may be maintained (such simplification/stability may be obtained by replacing and/or supplementing certain steps and/or components of a conventional laminoplasty with steps and/or components of the present invention (e.g., with an embodiment of the bone plate apparatus described herein). Such an open door laminoplasty is typically performed on a restricted spinal canal in the neck (e.g., a painfully restricted spinal canal), wherein the laminoplasty relieves pressure (e.g., immediately) by creating additional space for the spinal cord and roots.  
         [0031]     More particularly, such a laminoplasty is typically performed as follows: 
        The surgeon makes an incision on the back of the patient&#39;s neck.     The surgeon creates a “hinge” by cutting a groove down one side of the cervical vertebrae.     The surgeon cuts all the way through the other side of the vertebrae.     In order to create room for the bones to open like a door, the surgeon removes the tips of the spinal process.     In order to take pressure off the spinal cord and roots, the surgeon bends open the back of each vertebrae (like a door on its hinge).     The surgeon places, in the opened space of the door, appropriately sized wedges made of bone.     The surgeon allows the door to swing shut. Since the wedges stop the door from closing all of the way, the spinal cord and roots receive additional space.        
 
         [0039]     Referring now to  FIG. 6 , it is seen that Insertion Tool  601  may be used to aid insertion into a patient (e.g., to make placement quick and easy), and that Insertion Tool  601  may include Handle  603 , Shaft  605  and Mounting Mechanism  607  (which may be used to hold a bone plate and/or to aid in turning the various screws associated with the bone plate).  
         [0040]     Referring now to  FIG. 7 , a cut-away view of a bone plate apparatus according to an embodiment of the present invention is shown. Of note, this Fig. clearly shows Detents  703   a ,  703   b  and  703  as well as Machine Screw Retaining Thread  705 .  
         [0041]     Referring now to  FIG. 8 , another perspective view of two bone plate apparatus according to embodiments of the present invention are shown.  
         [0042]     In another embodiment, some or all of the components may include or be made essentially entirely from a commercially pure material (e.g., Titanium and/or Alloy Titanium).  
         [0043]     In another embodiment, Indications relating to use of the present invention may include (but not be limited to): 
        For use as laminoplasty plate for cervical spine (from C2-C7)     For use as orthognathic plate for fixation (e.g., permanent fixation) of bone segment(s) after a sagittal split Osteotomy.        
 
         [0046]     While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. For example, while the present invention has been described principally with respect to three bone screws, any desired number may, of course, be utilized. Further, the teeth, grooves and/or ridges may be placed at any desired position(s) on the bone plate apparatus. Further still, one or more slots may be utilized for one or more bone screws. Further still, any desired number of detents may be utilized. Further still, the angle between the portion of the bone plate shown principally with one bone screw and the portion of the bone plate shown principally with two bone screws may be any desired angle. Further still, any desired mechanism(s) for locking one or more bone screws relative to the bone plate may be utilized (instead of or in addition to the locking plate described above). Further still, the bone plate apparatus may, of course, have any desired dimensions (e.g., for any desired patient—man, woman or child). Further still, the bone plate apparatus of the present invention may be provided in a “line” or “family” of devices (e.g., small, medium and large; adult, child; male, female). Further still, the bone plate apparatus of the present invention may be provided in standard sizes. Further still, one or more components may be constructed of Ti, cobalt chromium, surgical steel and/or any combination thereof. Further still, a “hole” may be of any desired shape (e.g., circular, square, oval, rectangular, etc.). Further still, any steps relating to manufacture and/or use may be performed in any desired order.