Abstract:
The present invention is directed to an adjustable corpectomy device which fits within the intervertebral distracted channel. The device includes a means for engaging an extendable member to accommodate the distracted channel. The corpectomy implant device is defined by a main body, a first expandable plate, and an opposing second expandable plate. Each expandable plate is adapted to fit within the main body in a compressed state, and extends away from the main body in a non-compressed, expanded state.

Description:
PRIORITY CLAIM 
       [0001]    In accordance with 37 C.F.R. 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority to U.S. Provisional Patent Application No. 61/952,068, entitled “HINGED EXPANDABLE CORPECTOMY DEVICE”, filed Mar. 12, 2014. The contents of the above referenced application is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention generally relates to improvements to vertebral implants and, more particularly, to a longitudinally expandable vertebral implant including telescoping sections configured for incremental expansion by a ratchet expander for ease of securement at any desired increment in situ. 
       BACKGROUND OF THE INVENTION 
       [0003]    The spine consists of vertebrae that are categorized into sections known as the cervical, thoracic and lumbar section in a flexible arranged column. The vertebrae are separated by small cartilaginous cushions known as intervertebral discs. Intervertebral discs are oblate spherical structures that maintain the space between adjacent vertebrae. Each intervertebral disc consists of an outer annulus fibrosus, which surrounds the inner nucleus pulposus. The annulus fibrosus consists of several layers of strong annular fibrocartilage to contain the nucleus pulposus and distribute pressure evenly across the disc wherein a mucoprotein gel serves to absorb shocks. 
         [0004]    Deterioration of an intervertebral disc results in limited mobility and can cause severe pain. For instance, normal aging causes the nucleus pulposus to lose fluid and contract in volume resulting in a reduction in the intervertebral space. Any reduction of space between adjacent vertebrae may put pressure on the nerves of the spinal column. Further, a reduction in volume of the nucleus pulposus reduces the disc&#39;s ability to absorb shock which can result in disc herniation. The bulge of a herniated disc may also put pressure on nearby nerve structures resulting in pain as well as diminished range of motion. 
         [0005]    Surgical options are available including laminectomy and discectomy combined with vertebral fusion and/or dynamic stabilization. However, these surgical options are highly invasive and require prolonged hospitalization and recovery. More recently, artificial disc replacement prosthetics have been used to replace or augment all or part of the removed or resected intervertebral disc. 
         [0006]    In order to reduce the pain associated with the movement of the intervertebral joint, surgical intervention is often indicated as a means to alleviate pressure upon the spinal cord while concomitantly stabilizing the associated vertebrae. This involves a surgical procedure to distract the disc and or vertebra, or portions thereof, and the insertion of bone fusing material into the cavity of the opposing vertebra. Corpectomy devices have been developed to help support the spine and maintain the normal spacing between opposing vertebrae. Some of these devices may be packed with fusing material to ensure solid bone growth between the two vertebrae. Typically, corpectomy devices are manufactured at various heights requiring that a cavity between opposing vertebrae to be distracted to a dimension corresponding to the sized corpectomy device. The surgical procedure to prepare the implant site can be difficult and lengthy. Moreover, the procedure can increase risk of trauma to the tissues surrounding of the implant site. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is a longitudinally adjustable corpectomy device which fits within the intervertebral distracted channel. The device includes a means for engaging an extendable member to accommodate the distracted channel. An expanding member moves in relation to a main body in accordance with a hinged operation. 
         [0008]    An objective of the instant invention to provide a corpectomy device that may be adjusted within the intervertebral cavity or adjusted in situ within the cavity. 
         [0009]    It is a further objective of the instant invention to provide an expandable corpectomy which can be expanded by use of a hinged mechanism. 
         [0010]    Yet another objective of the instant invention is to provide vertebra engagable endplates which are arranged to pivot and self adjust. 
         [0011]    Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0012]      FIG. 1  is a perspective view of the corpectomy device in a compressed position with each plate compressed to the main body; 
           [0013]      FIG. 2A  a left side perspective view of the corpectomy device in an expanded position; 
           [0014]      FIG. 2B  is left side perspective view of the corpectomy device in an almost fully expanded position; 
           [0015]      FIG. 3  is a right side perspective view of the corpectomy device in a expanded position; 
           [0016]      FIG. 4  a left side perspective view of the corpectomy device in an expanded position with the main body removed; 
           [0017]      FIG. 5  a right side perspective view of the corpectomy device in an expanded position with the main body removed; 
           [0018]      FIG. 6  is the perspective view illustrating the expansion member; 
           [0019]      FIG. 7  is a pictorial view depicting the corpectomy device between vertebra in a compressed position; 
           [0020]      FIG. 8  illustrates the corpectomy implant device in accordance with the present invention in the compressed state between vertebra; 
           [0021]      FIG. 9  illustrates the use of a driver; 
           [0022]      FIG. 10  illustrates the corpectomy implant device in the expanded state. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated. 
         [0024]    Referring now to the Figures, set forth is a hinged, expandable corpectomy implant device, referred to generally as  10 . The corpectomy implant device  10  is defined by a main body  12 , a first expandable plate  14 , and an opposing second expandable plate  16 . Each expandable plate  14  and  16  is adapted to fit within the main body  12  in a non-expanded state, see  FIG. 1 . Referring to  FIGS. 2A and 2B , in an expanded state, each expandable plate  14  and  16  moves a distance from the main body  12 . The expandable plate  14  contains an upper surface  18  which can be smooth. In a preferred embodiment, the upper surface  18  contains surface configurations, such as ridges or teeth  20 . The teeth  20  are sized, shaped, and orientated to grip and secure to a surface, such as a vertebral bone. A side wall  22  extends away form the upper surface  18  and is set back to allow for at least a portion of the upper surface  18  to overhang. The first expandable plate upper side wall  22  is inserted into the main body  12  so that in the non-expanded position, the upper surface lies flush with the top end  24  of the main body  12 . Two slotted regions  26  and  28  are sized to receive an expansion member to be described later. 
         [0025]    The second expandable plate  16  contains an upper surface  30  which can be smooth. In a preferred embodiment, the upper surface  30  contains surface configurations, such as ridges or teeth  32 . The teeth  32  are sized, shaped, and orientated to grip and secure to a surface, such as a vertebral bone. A side wall  34  extends away form the upper surface  30  and is set back to allow for at least a portion of the second expandable plate upper surface to overhang. The second expandable plate upper wall side wall  34  is inserted into the main body  12  so that in the non-expanded position, a portion of the second expandable plate  16  lies flush with the bottom end  36  of the main body  12 . Two slotted regions  38  and  40  are sized to receive an expansion member to be described later. 
         [0026]    To provide for the expandable plates  14  and  16  to traverse between an expanded position and non-expanded position, the corpectomy implant device  10  comprises an expansion member  42 , illustrated as a toggle. The expansion member  42  is defined by a screw  44  operatively coupled to a plurality of pivotably connected to a pair of expansion member plates  46  and  48 . The screw head  50  is shaped to receive a rotation generating device, such as a drill bit or other driving tool, such as a screw driver, to provide the necessary rotational force to move the expansion member plates  46  and  48  relative to each other. 
         [0027]    In use, as the screw  44  is rotated, the expansion member plate  46  and the expansion member plate  48  pivot about hinge  52  from a first position in which the expansion member plates  46  and  48  from a generally V shaped orientation to an expandable state in which the expansion member plates  46  and  48  form a linear structure. Depending on the degree of expansion required, the expansion member plates  46  and  48  may assume a position in-between the non-expanded state and the fully expanded state. The expansion member  42  is designed so that the degree of expansion when the expansion member plates  46  and  48  are in the non-expansion state is greatest. As such, during the first few rotations, the degree of member plate separation is greatest. As the expansion member plates  46  and  48  reach their most distal heights, i.e. formation of a liner structure, plate separation is more difficult. Such feature allows the surgeon the capability to make fine adjustments at this point. 
         [0028]    Positioned at the distal end of each expansion member plate  46  and  48  are generally cylindrical bars  54  and  56 . The cylindrical bar  54  is sized and shaped to slidably engage slotted region  28 . The cylindrical bar  56  is sized and shaped to slidably engage slotted region  38 . As such, when screw  44  is engaged and rotates causing each expansion member plate  46  and  48  to pivot about hinge  52 , bar  54  slides within slotted region  28 . As the bar contacts the closed end  58 , the first expandable plate  14  moves. Concurrently, as bar  56  slides within slotted region  38  and contacts closed end  60 , the second expandable plate  16  moves, causing overall expansion. 
         [0029]      FIGS. 7-10  are pictorial views depicting the corpectomy implant device  10  between vertebra  62  and  64 .  FIG. 8  illustrates the corpectomy implant device  10  in the compressed state.  FIG. 9  illustrates the use of a driver  66 .  FIG. 10  illustrates the corpectomy implant device  10  in the expanded state. 
         [0030]    All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. 
         [0031]    It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. 
         [0032]    One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.