Patent Abstract:
A bodiless bone fusion method, apparatus and device for insertion between bones that are to be fused together and/or in place of one or more of the bones, such as, for example, the vertebrae of a spinal column. The bodiless bone fusion device comprises one or more extendable plates, one or more extending blocks in communication with the extendable plates, one or more positioning elements for adjusting the extendable plates by manipulating the extending blocks, and one or more support panels for holding the positioning elements and guiding the extendable plates. The plates are able to be advantageously positioned in the confined space between the vertebrae to help brace the device until the bone has fused.

Full Description:
RELATED APPLICATIONS 
       [0001]    This Application claims priority under 35 U.S.C. 119 (e) of the co-pending U.S. Provisional Application Ser. No. 61/794,789, filed Mar. 15, 2013, and entitled BODILESS BONE FUSION DEVICE, APPARATUS AND METHOD” and the co-pending U.S. Provisional Application Ser. No. 61/858,505, filed Jul. 25, 2013, and entitled BODILESS BONE FUSION DEVICE, APPARATUS AND METHOD,” both of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to bone fusion devices. More specifically, the present invention relates to bodiless devices for fusing vertebrae of the spine or other bones. 
       BACKGROUND OF THE INVENTION 
       [0003]    The spinal column is made up of vertebrae stacked on top of one another. Between the vertebrae are discs which are gel-like cushions that act as shock-absorbers and keep the spine flexible. Injury, disease, or excessive pressure on the discs can cause degenerative disc disease or other disorders where the disc becomes thinner and allows the vertebrae to move closer together or become misaligned. Similarly, vertebrae are able to weaken due to impact or disease reducing their ability to properly distribute forces on the spine. As a result, nerves may become pinched, causing pain that radiates into other parts of the body, or instability of the vertebrae may ensue. 
         [0004]    One method for correcting disc and/or vertebrae-related disorders is to insert a fusion cage as a replacement for and/or in between the vertebrae to act as a structural replacement for the deteriorated disc and/or vertebrae. The fusion cage is typically a hollow metal device usually made of titanium. Once inserted, the fusion cage maintains the proper separation between the vertebrae to prevent nerves from being pinched and provides structural stability to the spine. Also, the inside of the cage is filled with bone graft material which eventually fuses permanently with the adjacent vertebrae into a single unit. However, it is difficult to retain this bone graft material in the cage and in the proper positions to stimulate bone growth. 
         [0005]    The use of fusion cages for fusion and stabilization of vertebrae in the spine is known in the prior art. U.S. Pat. No. 4,961,740 to Ray, et al. entitled, “V-Thread Fusion Cage and Method of Fusing a Bone Joint,” discloses a fusion cage with a threaded outer surface, where the crown of the thread is sharp and cuts into the bone. Perforations are provided in valleys between adjacent turns of the thread. The cage can be screwed into a threaded bore provided in the bone structure at the surgical site and then packed with bone chips which promote fusion. 
         [0006]    U.S. Pat. No. 5,015,247 to Michelson entitled, “Threaded Spinal Implant,” discloses a fusion implant comprising a cylindrical member having a series of threads on the exterior of the cylindrical member for engaging the vertebrae to maintain the implant in place and a plurality of openings in the cylindrical surface. 
         [0007]    U.S. Pat. No. 6,342,074 to Simpson entitled, “Anterior Lumbar Underbody Fusion Implant and Method For Fusing Adjacent Vertebrae,” discloses a one-piece spinal fusion implant comprising a hollow body having an access passage for insertion of bone graft material into the intervertebral space after the implant has been affixed to adjacent vertebrae. The implant provides a pair of screw-receiving passages that are oppositely inclined relative to a central plane. In one embodiment, the screw-receiving passages enable the head of an orthopaedic screw to be retained entirely within the access passage. 
         [0008]    U.S. Pat. No. 5,885,287 to Bagby entitled, “Self-tapping Interbody Bone Implant,” discloses a bone joining implant with a rigid, implantable base body having an outer surface with at least one bone bed engaging portion configured for engaging between a pair of bone bodies to be joined, wherein at least one spline is provided by the bone bed engaging portion, the spline being constructed and arranged to extend outwardly of the body and having an undercut portion. 
         [0009]    U.S. Pat. No. 6,582,467 to Teitelbaum et al. entitled,“Expandable Fusion Cage,” discloses an expandable fusion cage where the surfaces of the cage have multiple portions cut out of the metal to form sharp barbs. As the cage is expanded, the sharp barbs protrude into the subcortical bone of the vertebrae to secure the cage in place. The cage is filled with bone or bone matrix material. 
         [0010]    U.S. Pat. No. 5,800,550 to Sertich entitled, “Interbody Fusion Cage,” discloses a prosthetic device which includes an inert generally rectangularly shaped support body adapted to be seated on hard end plates of vertebrae. The support body has top and bottom faces. A first peg is movably mounted in a first aperture located in the support body, and the first aperture terminates at one of the top and bottom faces of the support body. Further, the first peg projects away from the one of the top and bottom faces and into an adjacent vertebra to secure the support body in place relative to the vertebra. 
         [0011]    U.S. Pat. No. 6,436,140 to Liu et al. entitled, “Expandable Interbody Fusion Cage and Method for Insertion,” discloses an expandable hollow interbody fusion device, wherein the body is divided into a number of branches connected to one another at a fixed end and separated at an expandable end. The expandable cage may be inserted in its substantially cylindrical form and may be expanded by movement of an expansion member to establish lordosis of the spine. An expansion member interacts with the interior surfaces of the device to maintain the cage in the expanded condition and provide a large internal chamber for receiving bone in-growth material. These patents all disclose fusion cage devices that can be inserted between vertebrae of the spine in an invasive surgical procedure. Such an invasive surgical procedure requires a long recovery period. 
       SUMMARY OF THE INVENTION 
       [0012]    The present application is directed to a bodiless bone fusion method, apparatus and device for insertion between bones that are to be fused together and/or in place of one or more of the bones, such as, for example, the vertebrae of a spinal column. The bodiless bone fusion device comprises one or more extendable plates, one or more extending blocks in communication with the extendable plates, one or more positioning elements for adjusting the extendable plates by manipulating the extending blocks, and one or more support panels for holding the positioning elements and guiding the extendable plates. The bodiless bone fusion device is able to be inserted between or replace the vertebrae by using a minimally invasive procedure. After the device has been positioned between the vertebrae, and the positioning elements are able to be rotated to position the plates. In particular, the plates are able to be positioned by rotating the positioning elements causing extending blocks to move and push outwards against the plates as the extending blocks approach the ends of the bodiless bone fusion device. In some embodiments, a single plate is extended. Thus, the plates are able to be advantageously positioned in the confined space between the vertebrae to help brace the device until the bone has fused. 
         [0013]    A first aspect is directed to a bodiless bone fusion device for insertion into a desired location. The bodiless bone fusion device comprises an extending mechanism including one or more extending blocks mechanically coupled with a positioning element such that rotation of the positioning element causes the blocks to move with respect to the positioning element and a pair of plates straddling the extending mechanism and mechanically coupled with the extending blocks such that when the extending blocks move with respect to the positioning element, the plates move along a path with respect to each other between a retracted position in which the plates are adjacent to each other to an extended positioned in which the plates are spread apart from each other, wherein the plates are sized such that at least a portion of the perimeter of the plates about the path align with the outermost perimeter of the device about the path. In some embodiments, the plates are sized such that the entirety of the perimeter of the plates about the path align with the outermost perimeter of the device about the path. In some embodiments, the device further comprises one or more biasing elements physically coupled with both of the plates and positioned such that the biasing elements apply a force resisting the movement of the plates from the retracted position to the extended position. In some embodiments, the biasing elements have a shape selected from the group consisting of a ring, a C-shape and a ring-shaped coil. In some embodiments, the extending blocks each comprise an angled surface between a left side and a right side, wherein the left sides of the blocks are aligned with a left face of the plates and the right sides of the blocks are aligned with a right face of the plates. In some embodiments, angled surface forms a continuous sheet between the left and right sides of the blocks in order to increase the surface area of the angled surface. In some embodiments, the device further comprises a locking mechanism coupled with the positioning element and configured to physically bias the rotational orientation of the positioning element into one of a plurality of positions. In some embodiments, the locking mechanism comprises one or more stoppers each having a bump and a dial having one or more dimples and coupled with the positioning element such that the dial rotates with the positioning element, wherein the bumps do not rotate with the dial and the stoppers are positioned adjacent to the dial such that, when aligned, one or more of the bumps spring into one or more of the dimples. In some embodiments, the device further comprises one or more support panels coupled with the locking mechanism and the extending mechanism, wherein each of the support panels are positioned within a panel aperture on each of the plates such that as the plates move between the retracted and the extended positions the plates slide up or down the panels via the panels apertures. In some embodiments, at least one of the support panels comprises a pair of grip tabs that protrude from the sides of the support panel into a pair of grip apertures formed by the plates when the plates are in the retracted position. A second aspect is directed to a method of implanting a bodiless bone fusion device into a desired location. The method comprises inserting the bodiless bone fusion device in the desired location, wherein the bodiless bone fusion device comprises an extending mechanism including one or more extending blocks mechanically coupled with a positioning element such that rotation of the positioning element causes the blocks to move with respect to the positioning element and a pair of plates straddling the extending mechanism and mechanically coupled with the extending blocks such that when the extending blocks move with respect to the positioning element, the plates move along a path with respect to each other between a retracted position in which the plates are adjacent to each other to an extended positioned in which the plates are spread apart from each other, wherein the plates are sized such that at least a portion of the perimeter of the plates about the path align with the outermost perimeter of the device about the path and moving the plates between the retracted position and the extended position with the extending mechanism. In some embodiments, the plates are sized such that the entirety of the perimeter of the plates about the path align with the outermost perimeter of the device about the path. In some embodiments, the bodiless bone fusion device further comprises one or more biasing elements physically coupled with both of the plates and positioned such that the biasing elements apply a force resisting the movement of the plates from the retracted position to the extended position. In some embodiments, the biasing elements have a shape selected from the group consisting of a ring, a C-shape and a ring-shaped coil. In some embodiments, the extending blocks each comprise an angled surface between a left side and a right side, wherein the left sides of the blocks are aligned with a left face of the plates and the right sides of the blocks are aligned with a right face of the plates. In some embodiments, the angled surface forms a continuous sheet between the left and right sides of the blocks in order to increase the surface area of the angled surface. In some embodiments, the bodiless bone fusion device further comprises a locking mechanism coupled with the positioning element and configured to physically bias the rotational orientation of the positioning element into one of a plurality of positions. In some embodiments, the locking mechanism comprises one or more stoppers each having a bump and a dial having one or more dimples and coupled with the positioning element such that the dial rotates with the positioning element, wherein the bumps do not rotate with the dial and the stoppers are positioned adjacent to the dial such that, when aligned, one or more of the bumps spring into one or more of the dimples. In some embodiments, the bodiless bone fusion device further comprises one or more support panels coupled with the locking mechanism and the extending mechanism, wherein each of the support panels are positioned within a panel aperture on each of the plates such that as the plates move between the retracted and the extended positions the plates slide up or down the panels via the panels apertures. In some embodiments, at least one of the support panels comprises a pair of grip tabs that protrude from the sides of the support panel into a pair of grip apertures formed by the plates when the plates are in the retracted position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1A  illustrates a retracted perspective view of a bodiless bone fusion device according to some embodiments. 
           [0015]      FIG. 1B  illustrates an extended perspective view of a bodiless bone fusion device according to some embodiments. 
           [0016]      FIG. 2  illustrates a cross-sectional view of components of the bodiless bone fusion device according to some embodiments. 
           [0017]      FIG. 3A  illustrates a profile view of the bodiless bone fusion device with the plates retracted according to some embodiments. 
           [0018]      FIG. 3B  illustrates a profile view of the bodiless bone fusion device with the plates extended according to some embodiments. 
           [0019]      FIG. 4  illustrates a bodiless bone fusion device having a position locking mechanism according to some embodiments. 
           [0020]      FIG. 5  illustrates a flow chart of a method of using the bodiless bone fusion device according to some embodiments. 
           [0021]      FIG. 6A  illustrates a front view of the bodiless bone fusion device having a loop biasing element according to some embodiments. 
           [0022]      FIG. 6B  illustrates a front view of the bodiless bone fusion device having a C shape biasing element according to some embodiments. 
           [0023]      FIG. 6C  illustrates a front view of the bodiless bone fusion device having a garter spring biasing element according to some embodiments. 
           [0024]      FIG. 7  illustrates a side up-close view of a positioning element and stopper according to some embodiments. 
           [0025]      FIG. 8  illustrates a close-up view of support panels having retention tips according to some embodiments. 
           [0026]      FIG. 9A  illustrates a retracted perspective view of a bodiless bone fusion device having stretched extending blocks according to some embodiments. 
           [0027]      FIG. 9B  illustrates an extended perspective view of a bodiless bone fusion device having stretched extending blocks according to some embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    In the following description, numerous details and alternatives are set forth for purpose of explanation. However, one of ordinary skill in the art will realize that the invention can be practiced without the use of these specific details. For instance, the figures and description below often refer to the vertebral bones of a spinal column. However, one of ordinary skill in the art will recognize that some embodiments of the invention are practiced for the fusion of other bones, including broken bones and/or joints. In other instances, well-known structures and devices are shown in block diagram form in order not to obscure the description of the invention with unnecessary detail. 
         [0029]      FIGS. 1A and 1B  illustrate retracted and extended perspective views, respectively, of a bodiless bone fusion device  100  according to some embodiments. The bodiless bone fusion device  100  is able to be constructed from a high strength biocompatible material, such as titanium, which has the strength to withstand compressive and shear forces in the spine that are generated by a patient&#39;s body weight and daily movements. Alternatively, part of all of the bodiless bone fusion device  100  is able to be constructed from one or more of the group consisting of high strength biocompatible material or a polymer such as PEEK, PEKK, and other polymeric materials know to be biocompatible and having sufficient strength. In some embodiments, the materials used to construct the bodiless bone fusion device include using additives, such as carbon fibers for better performance of the materials under various circumstances. The base biocompatible material is often textured or coated with a porous material conducive to the growth of new bone cells on the bodiless bone fusion device  100 . 
         [0030]    The bodiless bone fusion device  100  is able to have several conduits or holes  120  which permit the bone graft material to be inserted into the device  100  and to contact the vertebral bone before or after the device  100  has been inserted between the vertebrae of the patient. In particular, one or more holes  120  are able to be positioned on the lateral faces of the device  100  through one or both of the plates  102  such that the bone graft material is able to be inserted into the open spaces within the device  100  when the device is in the contracted position. It is understood that although only one conduit  120  on a lateral face is shown in  FIG. 1A , any number of conduits  120  on lateral faces or other parts of the device  100  is contemplated. The bone graft material and the surface texturing of the device  100  encourage the growth and fusion of bone from the neighboring vertebrae. The fusion and healing process will result in the bodiless bone fusion device  100  aiding in the bridging of the bone between the two adjacent vertebral bodies of the spine which eventually fuse together during the healing period. As shown in  FIGS. 1A and 1B , the bodiless bone fusion device  100  comprises one or more extendable plates  102 , one or more support panels  104 , one or more extending blocks  106 , one or more positioning elements  108  and one or more biasing elements  110 . The positioning element  108  is rotatably positioned within panel apertures  103  of the support panels  104  and operably coupled with the one or more extending blocks  106 . The support panels  104  are slidably positioned within plate apertures  118  of the extendable plates  102  and within a grip channel  114  of the extendable plates  102  when the device  100  is in the retracted position as shown in  FIG. 1A . The biasing element  110  is positioned within biasing channels  112  on one or both ends of the extendable plates  102 . In some embodiments, one or more of the holes  120 , the grip channels  114 , the biasing elements  110  and/or biasing channels  112  are able to be omitted. In some embodiments, one or more additional components are able to be added as are well known in the art. Additionally, it is noted that although  FIGS. 1A and 1B  only show two plates  102 , a single positioning element  108 , two extending blocks  106 , two support panels  104  and two biasing elements  110 , any number of plates  102 , positioning elements  108 , extending blocks  106 , support panels  104  and/or biasing elements  110  is contemplated. 
         [0031]    The one or more extending blocks  106  each are able to comprise a threaded conduit  122  for operably coupling to the positioning elements  108 . In particular, as described below, the positioning elements  108  are able to comprise a plurality of threaded screws having different diameters wherein the threaded conduits  122  of the extending blocks  106  are able to be configured to screw onto or otherwise engage with one of the threaded screws of the positioning elements  108 . Alternatively, one or more of the screws are able to have the same diameter. Further, each of the extending blocks  106  are able to comprise angled upper and/or lower outer surfaces for contacting/engaging angled inner surfaces  123  (see  FIGS. 3A and 3B ) of the extending plates  102 . Specifically, the angled outer surfaces are able to be configured such that as the blocks  106  move along the positioning element  108  the angles outer surfaces push against the angled inner surfaces  123  causing the plates  102  to move outwards. 
         [0032]    The support panels  104  are able to be sized/configured to slidably fit within one or more plate apertures  118  within the extendable plates  102 . In some embodiments, one or more of the plate apertures  118  extend completely through the corresponding plate  102 . Alternatively, one or more of the plate aperture  118  are able to only extend partially through the corresponding plate  102 . When in the retracted position, the top and bottom portions of the support panels  104  are able to be positioned fully within a plate aperture  118  of each of the extendable plates  102  (e.g. such that the edge of the support panels  104  is substantially flush with the surface of the plates  102  if the plate aperture  118  extends through the top of the plate  102 ). As the plates  102  are extended outward to the extended position, the plates  102  slide up the panels  104 , but the panels  104  remain at least partially within the plate apertures  118  even when in the fully extended position. In some embodiments, as shown in  FIG. 8 , the top and/or bottom of the panels  104  comprise one or more retention tips  101  that bow out or otherwise protrude out from the top and/or bottom of the panels  104  in order to block or mechanically stop the plates  102  from sliding off the top of the panels  104 . For example, the retention tips  101  are able to extend out from the panels  104  and if the plates  102  slide up to the retention tips on the panel  104 , the tips  101  provide a biasing force that pushes the plates  102  back down the panels  104  until they no longer contact the retention tips  101 . Alternatively, other types of fasteners or stopping mechanisms are able to be used to prevent the plates  102  from sliding of the panels  104  as are well known in the art. 
         [0033]    As a result, the panels  104  are able to maintain the alignment of the plates  102  with each other and with the positioning element  108  and extending blocks  106 . Also, as described above, the support panels  104  are each able to comprise one of the panel apertures  103  such that the panels  104  are able to receive one end of the positioning element  108 . Specifically, the panel apertures  103  are able to be configured to receive a non-threaded portion of an end of the positioning element  108  such that the positioning element  108  is held in place relative to the support panels  104 , but allowed to rotate within the panel apertures  103 . One or more of the support panels  104  are also able to comprise one or more grip tabs  105  that extend out the sides of the support panels  105 . As described below, the grip tabs  105  are configured to fit within the grip channels  114  of the plates  102  and provide a gripping point to an insertion instrument used to insert and otherwise manipulate the device  100 . In some embodiments, the grip tabs  105  comprise one or more indentations, conduits and/or fasteners for receiving detachably coupling with an insertion tool. For example, the grip tabs  105  are able to be configured such that they create a profile that matches the profile of the insertion tool such that the tool is able to securely grip the device  100  via the grip tabs  105 . 
         [0034]    The extendable plates  102  are able to be located on opposite sides of the device  100  and face is opposite directions. Internally, the plates  102  are able to have one or more angled inner surfaces  123  (see  FIGS. 3A and 3B ) that have end thicknesses that are larger than their middle thicknesses such that the thickness of the angled surfaces  123  gradually increases while going from the middle to the ends of the plate  102 . Alternatively, the angled inner surfaces  123  are able to be configured such that they have end thicknesses that are smaller than their middle thicknesses such that the thickness of the angled surfaces  123  gradually decreases while going from the middle to the ends of the plate  102 . In either configuration, the angles surfaces  123  are able to interact with the extending blocks  106  to cause the plates  102  to retract or extend between the retracted and extended positions. As described above, the plates  102  each comprise one or more plate apertures  118  that are sized to slidably receive the top or bottom of the support panels  104 . As a result, the panels  104  are able to keep the plates  102  in alignment with each other as the plate  102  slide up and down along the support panels  104 . Additionally, in some embodiments the panels  104  are able to be shaped similar to the grip tabs  105  and/or other shapes such that the panels  104  are able to both support the plates  102  as well as enable the plates  102  to slide along the panels  104 . 
         [0035]    As also described above, the plates  102  each able to comprise the one or more biasing channels  112 . In particular, the biasing channels  112  are able to be configured such that when the device  100  is in the retracted position the biasing channels  112  of the plates  102  align to form a continuous channel that crosses between the plates  102 . In some embodiments, the biasing channels  112  are able to align at two or more positions between the plates  102  to form a continuous loop or other shape that crosses multiple times between the plates  102 . In some embodiments, the biasing channels  112  include a lip guard  111  that holds the biasing elements  110  within the biasing channels  112 . Alternatively, the biasing channels  112  are able to comprise coupling elements (not shown) that enable the biasing elements  110  to directly couple to the biasing channels  112  in order to stay within the channels  112 . Although as shown in  FIG. 2  the lip guard  111  is substantially straight forming a square-like channel  112 , it is contemplated that the guard  111  is able to be angled, rounded, indented or otherwise shaped such that the guard  111  is able to retain the biasing elements  110  within the biasing channels  112 . Further, the biasing channels  112  are able to each include one or more portions that are nonparallel to the direction in which the plates  102  are able to be extended in order to fit a biasing element  110  that provides resistence to the extension of and biases the plates  102  in the retracted position. In some embodiments, as shown in  FIGS. 1A and 1B  the biasing channels  112  form a C shape. Alternatively, the biasing channels  112  are able to form a loop (see FIGS.  6 A- 6 C), snake or other shapes having nonparallel portions as are well known in the art. Alternatively, the biasing channels  112  are able to be entirely parallel but be coupled to the biasing element  110  such that a nonparallel portion is unnecessary to provide the force resisting extension of the plates  102 . In some embodiments, the biasing channels  112  are positioned on the ends of the plates  102  as shown in  FIGS. 1A and 1B . Alternatively, one or more of the biasing channels  112  are able to be positioned on another lateral face or faces of the plates  102 . 
         [0036]    Additionally, the plates  102  are able to have serrated edges or teeth  136  to further increase the bodiless bone fusion device&#39;s gripping ability and therefore ability to be secured in place between the bones for both a long-term purchase and a short-term purchase. In some embodiments, the serrated edges or teeth  136  are able to be in a triangular or form a triangular wave formation as shown in  FIG. 2 . Alternatively, the serrated edges or teeth are able to be filleted, chamfered, or comprise other teeth shapes or edge waves as are well known in the art. As described above, the plates  102  are able to comprise the grip channels  114  positioned on opposite sides of one or more ends of the plates  102 . The grip channels  114  are able to be configured such that when the device  100  is in the retracted position the grip channels  114  of the plates  102  align and are partially filled by grip tabs  105  of the support panels  105 . The remainder of the grip channels  114  is able to be configured to receive gripping fingers of an insertion instrument (not shown). In particular, the grip channels  114  enable the insertion instrument to grip the grip tabs  105  of one of the support panels  104  to manipulate the device  100  and to prevent the device  100  from slipping or during insertion into a patient. Alternatively, the grip tabs  105  are able to comprise one or more screw holes or other types of fasteners for fastening to an insertion instrument as are well known in the art. 
         [0037]    Finally, the plates  102  are able to be configured such that when in the retracted position the extendable plates  102  house or surround the remainder of the components of the device  100 . As a result, the bodiless bone fusion device  100  provides the advantage of maximizing the plate size to device size ratio because the size of the plates  102  is equal to the size of the device  100  in the retracted position creating a 1 to 1 ratio. This enables the device  100  to incorporate larger plates  102  that increase stability and surface area, which would not be possible with devices that incorporate a body. Additionally, it should be noted that one or more of the plates  102  are able to be non-flat, non-parallel to each other, or otherwise non-uniform. For example, one or more of the plates  102  are able to be partially or fully concave, convex and/or angled. Further, in some embodiments one or more of the plates  102  are able to be adjustable or interchangeable such that they enable adjustments to their surface/body shape. 
         [0038]    The positioning element  108  is able to comprise a positioning aperture  109 , a first screw  107 A and a second screw  107 B coupled together (see  FIG. 2 ). The positioning aperture  109  is configured to receive a drive/engaging mechanism of a tool (not shown) such that the tool is able to rotate the positioning element  108 . The positioning aperture  109  is able to comprise numerous shapes and sizes as are well known in the art. Alternatively, the positioning aperture  109  is able to be omitted and/or the end of the positioning element  108  is able to be shaped to fit within the drive/engaging mechanism of the tool. The first screw  107 A is threaded opposite of the second screw  107 B. For example, if the first screw  107 A is left threaded, the second screw  107 B is right threaded or vice versa. Furthermore, the first screw  107 A is of a slightly different size than the second screw  107 B. As described above, the positioning element  108  is able to be operably coupled to one or more of the extending blocks  106 . For example, a first one of the extending blocks  106  is able to be threaded onto the first screw  107 A and a second one of the extending blocks  106  is able to be threaded on to the second screw  107 B. 
         [0039]    When coupled to the positioning element  108 , the extending blocks  102  are able to be positioned in the middle of the bodiless bone fusion device  100  in the retracted position. When the positioning element  108  is turned appropriately, the extending blocks  106  each travel outwardly on their respective screws  107 A and  107 B. As the extending blocks  106  travel outwardly, they push the angles surfaces  123  of the plates  102  causing the plates  102  to extend outward along the support panels  104 . In other words, the inner plate surface  123  when in contact with the extending blocks  106  act in such a manner so as to push the respective plates  102  apart. Thus, the plates  102  will be fully extended when the extending blocks  106  reach the opposite ends of the screws  107 A,  107 B. To retract the plates  102 , the positioning device  108  is turned in the opposite direction and the extending blocks  106  will each travel back to the middle on their respective screws  107 A and  107 B. It is contemplated that the operation of the device  100  is able to be reversed such that the plates  102 , extending blocks  106 , and positioning element  108  are configured such that the extending blocks  106  travel inwardly to extend the plates  102  into the extended position and travel outwardly to retract the plates  102  into the compact position. In any case, the nonextended plates  102  of the bodiless bone fusion device  100  provide a compact assembly that is suitable for insertion into the patient&#39;s body through a open, or minimally invasive surgical procedure. As used herein, an open or a minimally invasive procedure comprises a procedure wherein a smaller surgical incision is employed as compared to the size of the incision required for conventional invasive surgery, for example arthroscopic procedures. Moreover, minimally invasive procedures minimize or eliminate the need for excessive retraction of a patient&#39;s tissues such as muscles and nerves, thereby minimizing trauma and injury to the muscles and nerves and further reducing the patient&#39;s recovery time. The biasing elements  110  are able to be configured to fit within the biasing channels  112  of two or more plates  102  when the plates  102  are in alignment. For example, as shown in  FIGS. 1A ,  1 B and  6 B, one or more of the biasing elements  110  are able to shaped in a C shape or broken loop shape. Alternatively, as shown in  FIG. 6A , one or more of the biasing elements  110  are able to have a circular, oval or loop shape. Alternatively, as shown in  FIG. 6C , one or more of the biasing elements  110  are able to have a garter spring shape or any other type of shape formed by the biasing channels  112 . Further, the biasing element  110  are able to be shaped to fit behind the lip guard  111  such that the lip guard  111  holds the biasing element  110  in place within the biasing channels  112 . Alternatively, the biasing element  110  is able to directly couple to the plates  102  in order to stay within the biasing channels  112 . In some embodiments, the biasing elements  110  are able to be structured and/or positioned such that their body blocks the extension of the plates  102  and thus the extension of the plates  102  causes deformation and/or stretching of the body of the biasing elements  110 . As a result, the body deformation and/or stretching resistence of the biasing elements  100  provides an extension-resisting force that biases the plates  102  in the retracted position. This biasing provides the advantage of ensuring that the plates  102  remain in contact with extending blocks  106  as the plates  102  are extended and/or retracted. In some embodiments, one or more of the biasing elements  110  comprise nitinol to provide the deformation resistant and/or flexible structure. Alternatively, the biasing elements  110  are able to comprise other material having deformation resistant, springing and/or elastic properties as are well known in the art. 
         [0040]      FIG. 2  illustrates a cross-sectional view of components of the bodiless bone fusion device  100  according to some embodiments. As shown in  FIG. 2  and described above, the positioning element  108  is able to comprise a first screw  107 A and a second screw  107 B wherein the first screw  107 A is threaded differently than that of the second screw  107 B and is a different size than the second screw  107 B. For example, in some embodiments the first screw  107 A is an 8-32 screw and the second screw is a 6-32 screw. A first extending block  106 A and a second extending block  106 B are utilized with the positioning element  108  to extend and retract one or more of the plates  107 A with respect to each other and/or the positioning element  108 . The first extending block  106 A has an internal opening and threading to fit around the first screw  107 A. The second extending block  106 B has an internal opening and threading to fit around the second screw  107 B. The support panels  104  are coupled with the positioning element  108  via the plate apertures  118  of the plates  102 . Specifically, because the plate apertures  118  receive the ends of the support panels  104 , they prevent the panel apertures  103  of the support panels  104  from moving axially with respect to the positioning element  108  thereby keeping the ends of the positioning element  108  within the panel apertures  103 . Further, the plates  102  are each coupled with each other via the support panels  104  that maintain the alignment of the plates  102  and the biasing elements  110  that hold the plates  102  onto the support panels  104 .  FIG. 3A  illustrates a profile view of the bodiless bone fusion device  100  with the plates  102  retracted according to some embodiments. When the extending blocks  106  are positioned in the middle of the positioning element  108  with the first screw  107 A and the second screw  107 B, the plates  102  are positioned adjacent and/or in contact with each other.  FIG. 3B  illustrates a profile view of the bodiless bone fusion device  100  with the plates  102  extended according to some embodiments. As shown in  FIG. 3A , the bodiless bone fusion device  100  is compressed/retracted when the extending blocks  106  are in the middle of the bodiless bone fusion device  100 . As a user rotates the positioning element  108  via the positioning aperture  109 , the extending blocks  106  gradually move outward from the middle. If the user turns the positioning element  108  in the opposite direction, the extending blocks move back towards the middle. As the extending blocks  106  are moving outward, the extending blocks  106 A,  106 B push on inner angles surfaces  123  of the plates  102 . The plates  102  extend because the extending blocks  106  exert force against the angled inner surfaces  123  of the plates  102  outwardly as shown by the arrows  140 . When the extending blocks  106  are positioned near the ends of the bodiless bone fusion device  100 , the plates  102  extend beyond the outer edges of the ends of the support panels  104  of the bodiless bone fusion device  100  and ultimately secure the bodiless bone fusion device  100  between two bones. In operation, the bodiless bone fusion device  100  is initially configured in a compact position such that the extending blocks  106 A,  106 B are located in the middle of the bodiless bone fusion device  100  thereby allowing the plates  102  to contact each other and/or the edges of the ends of the support panels  104  to be substantially flush with the outer surfaces of the plates  102  through the plate apertures  118 . The compact bodiless bone fusion device  100  is then inserted into position within the patient and surgeon is able to expand the bodiless bone fusion device  100  by rotating the positioning element  108  which moves the extending blocks  106 A,  106 B towards the opposing ends of the bodiless bone fusion device  100 —one near the head of the positioning element  108  and the other towards the tail of the positioning element  108 . As the extending blocks  106 A,  106 B move away from the middle, the plates  102  are pushed outwardly from the pressure of the extending blocks  106 A,  106 B against the angled inner surfaces  123 . 
         [0041]    Eventually the extending blocks  106 A,  106 B exert a satisfactory force between the extended plates  102  and the bones to be fused. At that point the bodiless bone fusion device  100  is able to remain in place. If the plates  102  are extended too far, the surgeon is able to rotate the positioning element  108  in the opposite direction moving the extending blocks  106 A,  106 B back towards the middle. At the same time, the biasing elements  110  exert a retraction force in the opposite direction of the force  140  that ensures the plates  102  retract as the extending blocks  106 A,  106 B move back towards the middle of the device  100 . In particular, the retraction force is able to be applied to the plates  102  by biasing elements  110  throughout operation of the device  100  in order to both keep the plates  102  from sliding off the support panels  104  and keep the plates  102  in contact with the extending blocks  106  as the blocks  106  move along the positioning element  108 . Thereafter, material for fusing the bones together is inserted through the holes and openings  120  within the bodiless bone fusion device  100 . Alternatively, the insertion of the material for fusing the bones together is able to be omitted. 
         [0042]      FIG. 4  illustrates a bodiless bone fusion device  400  having a position locking mechanism  402  according to some embodiments. The bodiless bone fusion device  400  shown in  FIG. 4  is substantially similar to the bodiless bone fusion device  100  except for the differences described herein. It is noted that the plates  102  of the bone fusion device  400  have been omitted from  FIG. 4  for the sake of clarity. As shown in  FIG. 4 , at least one of the support panels  104  comprises one or more additional panel apertures  99  configured to receive a position locking mechanism  402 , wherein the position locking mechanism  402  comprises one or more dials  404  and one or more stoppers  406 . The dial  404  is configured to rotatably fit within the panel apertures  99  and comprises a dial aperture  412  and one or more dimples  410  along the edge or perimeter of the dial  202 . The dial aperture  412  is able to be sized or otherwise configured to receive an end of the positioning element  108  such that if the positioning element  108  is within the dial aperture  412 , the end of the positioning element  108  will cause the dial  404  to rotate along with the positioning element  108 . In some embodiments, the positioning element  108  causes the dial  404  to rotate by directly physically contacting the dial aperture  412 . 
         [0043]    Alternatively, the positioning element  108  is able to cause the dial  404  to rotate via indirect contact. The one or more dimples  410  are able to be configured to receive one or more bumps  408  of the stoppers  406 . In particular, the dimples  410  are able to have concave dimensions that substantially match convex dimensions of the bumps  408 . The stoppers  406  are able to be configured to fit within the panel apertures  99  adjacent to the dial  404  and comprise one or more bumps  408 . The stoppers  406 , dials  404  and apertures  99  are configured such that when within the apertures  99 , the stoppers  406  are adjacent or in contact with the dial  404  and the bumps  408  of the stoppers  406  snap or spring fit within the dimples  410  of the dial  404  when a dimple  410  and a bump  408  are aligned. Additionally, when a dimple  410  and a bump  408  are not aligned, the bump  408  is compressed against the dimple-less edge of the dial  404  and primed to spring or decompress into a dimple  410  when alignment is achieved. 
         [0044]    In some embodiments, the dial  404  is held in place within the additional panel apertures  99  by force applied by the bumps  408  of the stoppers  406 . For example, in some embodiments the dimples  410  are able to be concave and centered along the perimeter of the dial  404  such that when the bumps  408  are within the dimples  410  the outer walls of the concavity of the dimples  410  prevents the dial  404  and/or the stoppers  406  from falling out of place. As another example, as shown in  FIG. 7  the dial  404  is able to be omitted or incorporated into the positioning element  108 , wherein the perimeter of the positioning element  108  that is adjacent the stoppers  406  forms a trough or channel  401  that receives the stoppers  406  such that the positioning element  108  is unable to come out of position with respect to the stoppers  406 . In such embodiments, the bottom of the trough is able to comprise the dimples  410  for receiving the bumps  408  of the stoppers  406 . Alternatively, the dial  404  is able to be otherwise coupled or uncoupled within the apertures  99  by one or more fastening elements as are well known in the art. 
         [0045]    In some embodiments, the stoppers  406  are held in place within the additional panel apertures  99  by place holders  407 . In particular, the place holders  407  are able to be tensioned and/or compressed by the wall of the apertures  99  when the stoppers  406  are inserted into the apertures  99  and thus provide a spring force against the walls of the apertures  99  to try and relieve that tensioning/compression. Accordingly, the spring force holds the stoppers  406  within the apertures  99 . Alternatively, one or more of the stoppers  406  are able to be otherwise coupled or uncoupled within the apertures  99  by one or more fastening elements as are well known in the art. Although as shown in  FIG. 4 , the device  400  comprises one of the panels  104  including the position locking mechanism  402 , wherein the position locking mechanism  402  comprises a single dial  404  having sixteen dimples  410  and two stoppers  406 , it is understood that any number of the panels  104  are able to include a position locking mechanism  402  and the position locking mechanism is able to include any number of dials  404  having any number of dimples  410  coupled to any number of stoppers  406 . In some embodiments, the additional panel apertures  99  are able to replace the panel aperture  103  and/or the dial aperture  410  is able to be substantially similar to the panel aperture  103  in size and shape. 
         [0046]    In operation, as the positioning element  108  is rotated to extend or retract the plates  102 , the dial  404  is rotated along with the positioning element  108  and the bumps  408  compress and decompress into and out of the dimples  410  as they move in an out of alignment with the bumps  408 . As a result, each point during the rotation of the positioning element  108  that results in an alignment of a bump  408  and a dimple  410  serves as a demarcated degree of rotation and/or degree of extension/retraction of the plates  102 . In this way, the position locking mechanism  402  provides the advantage of enabling a user to rotate the positioning element  108  and thereby extend the plates  102  to predetermined rotation/extension amounts and/or by predetermined rotation/extension intervals represented by the spacing and number of dimple  410  and bump  408  alignment points. For example, the position and/or number of dimples  410  and/or bumps  408  of the position locking mechanism  402  is able to be adjusted to adjust the number and/or position of the alignment points and therefore the number and/or position of plate extension points. Thus, the position locking mechanism  402  of the bodiless bone fusion device  400  is able to be tuned to different size devices  400  based on the number of extension increments needed and the desired extension distance interval between each of the increments. In some embodiments, the increments are configured to be constant. Alternatively, the increments are able to be configured to decrease in size as the plates  102  approach the maximum extension level. Alternatively, other increment profiles are able to be used as are well known in the art. Further, the compression of the bumps  408  and their resistance thereto during rotation of the positioning element  108  between alignment points provides a slipping resistance force the resists unintended rotation of the positioning element  108  out of an alignment point. As a result, the position locking mechanism  402  provides the advantage of reducing the chance of the positioning element  108  unintentionally rotating and/or the plates  102  unintentionally extending or retracting. 
         [0047]      FIG. 5  illustrates a flow chart of a method of using a bodiless bone fusion device according to some embodiments. A user pre-configures the one or more plates  102  of the bodiless bone fusion device to the retracted position with the positioning element  108  and the one or more extending blocks  106  such that the device has a minimized form factor at the step  502 . The user inserts the bodiless bone fusion device into a desired position in between the bones at the step  504 . The user extends the plates  102  to a desired extension level between the bones by rotating the positioning element  108  causing the extending blocks  106  to push the plates  102  outward to the desired extension level at the step  506 . In some embodiments, the rotating of the positioning element  108  comprises rotating the positioning element  108  through a number of alignment points of the position locking mechanism  402  until a desired alignment point is reached. As a result, the method is able to provide the benefits of a minimally invasive surgery due to the minimized form factor of the bodiless bone fusion device in the retracted position and a more accurate and stable extension point due to the position locking mechanism.  FIGS. 9A and 9B  illustrate a retracted perspective view and an extended perspective view of a bodiless bone fusion device  900  having stretched or expanded extending blocks according to some embodiments. The bodiless bone fusion device  900  shown in  FIGS. 9A and 9B  is substantially similar to the bodiless bone fusion device  100  except for the differences described herein. Specifically, the sides  902  of the extending blocks  106  shown in  FIGS. 9A and 9B  extend such that the sides  902  substantially align with the outer surface of the device  900 . 
         [0048]    As a result, the extending blocks  106  span the entire width of the plates  102  which creates greater surface area for the blocks  106  to contact the plates  102  as well as greater stability in the extended position as a wider portion of the plates  102  is directly contacted/supported by the blocks  106 . In such embodiments, the skirt or sides  904  of the plates  102  are able to comprise a block cavity  906  configured to receive the sides  902  of the blocks  106  when the device  900  is in the retracted position. Although as shown in  FIGS. 9A and 9B , both sides  902  of both blocks  106  are expanded to align with the exterior surface of the sides  904  of the plates  102 , one or more of the sides  902  of one or more of the blocks  106  are able to not be expanded and/or be expanded less. For example, one of the sides  902  of one of the blocks  106  is able to extend part way into the cavity  906  on one of the sides  904  of the plates  102 . 
         [0049]    Thus, the bodiless bone fusion device, apparatus and method described herein has numerous advantages. Specifically, the bodiless bone fusion device provides the advantage of maximizing the plate size to device size ratio because the size of the plates is equal to the size of the device in the retracted position creating a 1 to 1 ratio. This enables the device to incorporate larger plates that increase stability and surface area, which would not be possible with devices that incorporate a body. Also, the device provides the advantage of the grip channels that ensure the non-slippage of the driving mechanism during the operation of the bone fusion apparatus. 
         [0050]    Further, the position locking mechanism provides the advantage of reducing the chance of the positioning element unintentionally rotating and/or the plates unintentionally extending or retracting. Also, as mentioned above, the method of use requires only a small incision and minimally invasive surgical procedure advantageously promoting health and rapid recovery by the patient. Indeed, bone growth occurs around the bodiless bone fusion device and particularly at the locations of the extended plates, such that the bodiless bone fusion device is further secured by the bone growth, which further promotes a superior, robust bone fusion result. Moreover, the device provides the advantage of extending blocks that span the entire width of the plates thereby creating greater surface area for the blocks to contact the plates as well as providing greater stability in the extended position as a wider portion of the plates is directly contacted/supported by the blocks. 
         [0051]    The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modification may be made in the embodiments chosen for illustration without departing from the spirit and scope of the invention. For example, it should be noted that although the above bodiless bone fusion devices are described in reference to a pair of extending blocks, a pair of screws, and wherein each plate is shaped such that the ends are larger than the middle, and the size of the plate gradually increases while going from the middle to the ends, the use of a single extending block in the above embodiments is contemplated. Specifically, if using a single extending block, the above embodiments would operate the same except the positioning element would comprise a single screw that when engaged would cause the single extending block to move from one end of the screw to the other end thereby exerting a force against the plates such that they move into the extended position. In such embodiments, each plate is shaped such that one end is larger than the opposite end, and the size of the plate gradually increases going from the smaller end to the larger end.

Technology Classification (CPC): 0