Abstract:
A modular implant device for placement between two adjacent vertebrae during a surgical procedure. The implant device comprises a distractor/nosecone portion configured for placement in a first location between the vertebrae and providing distraction and fixation of a desired vertical separation between the vertebrae at the first location. An alignment guide being a long slender element has a first end inserted into the distractor/nosecone portion and extending away from the distractor/nosecone portion, where the alignment guide is used to position the distractor/nosecone portion in the first location between the vertebrae. A body portion is configured for placement in a second location between the vertebrae, providing distraction and fixation of a desired vertical separation between the vertebrae at the second location, where the body portion includes a bore to receive the alignment guide, and the body portion is translated along the alignment guide into position between the vertebrae.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the priority date of U.S. Provisional Patent Application Ser. No. 62/183,426, titled, Modular Interbody Alignment Device, filed Jun. 23, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The invention relates to the field of interbody devices, and more specifically, to a modular interbody device and alignment guide for use during a surgical implant procedure, particularly a spinal fusion procedure. 
       Description of the Related Art 
       [0003]    Implants are typically placed as unitary (single piece) devices that require space distraction (separation of bones) and proper device placement simultaneously. Placement of a large unitary device is much more difficult than a small component. Guidewires have been described and used for placement of implants but such wires are not fixated and provide no structural advantage while implanting the device/implant. 
       SUMMARY OF THE INVENTION 
       [0004]    In one or more embodiments, a modular interbody alignment device is disclosed having a distractor portion and an alignment guide extending therefrom. A subsequent implant or implants, or parts thereof may be coupled to the distractor portion using the alignment guide. 
         [0005]    In accordance with one embodiment, the distractor portion (also referred to herein as a nosecone) with the alignment guide coupled thereto is employed to provide initial space distraction, such as intervertebral space, reconstitution of disc space height and proper device placement. Once the distractor portion/nosecone is properly positioned, the alignment guide extending therefrom is, by virtue of the proper position of the nosecone, properly positioned for receipt of the subsequent implant part(s). 
         [0006]    The subsequent implant part may be a principal portion of an implant, and may provide the bulk of interbody structural support. The subsequent implant may be referred to herein as the “body portion” of the implant. The alignment guide may serve as fixation component operable to fix the distractor portion/nosecone and body portion one to the other. 
         [0007]    In another embodiment, an interbody device includes an implant having a first, distractor portion and a second, separate body portion which may be coupled to the distractor portion. The distractor portion may include an opening for receiving an alignment guide, or may include an integral alignment guide extending therefrom. The body portion includes a bore for receiving the alignment guide. The bore facilitates slidable engagement between the body portion and the alignment guide. The alignment guide may be configured and operable to not only bring the distractor portion and body portion into contact, but also to fix them together. Alternatively, or in addition, the distractor portion and the body portion may have complementary mating surfaces operable to connect the portions. 
         [0008]    The alignment guide may be “keyed” to allow for proper placement of subsequent implants without malrotation. 
         [0009]    Devices in accordance with one or more embodiments may be employed in various surgical applications, including but not limited to ALIF (Anterior Lumbar Interbody Fusion), PLIF (Posterior), TLIF (Transforaminal) and LLIF (Lateral) interspinous fixation, fracture fixation, endosurgery, cardiovascular surgery, etc. 
         [0010]    For example, in the case of an interbody implant, a first portion of an implant, or nosecone, acts as an interbody distractor and trial. This results in easier placement of the second portion, or body portion, of the implant with lessened risk of endplate damage. The distractor/nosecone portion is part of the final implant system. The small footprint of the nosecone portion provides for reliable and correct positioning of the whole implant. The first portion/nosecone of the implant may be stabilized by ancillary endplate fixation. The alignment guide may be used to secure and fixate first and second implant portions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    For the purposes of illustration, there are forms shown in the drawings that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
           [0012]      FIG. 1  is a perspective view illustration of a device in accordance with one or more embodiments of the present disclosure; 
           [0013]      FIG. 2  is a front view illustration of a body portion of the device of  FIG. 1 ; 
           [0014]      FIG. 3  is an anterior view illustration of a distractor portion and alignment guide positioned in an intervertebral space according to an embodiment of the present disclosure; 
           [0015]      FIG. 4  is a lateral view illustration of the distractor portion and alignment guide positioned in an intervertebral space according to  FIG. 3 ; 
           [0016]      FIG. 5  is an anterior view illustration of a distractor portion, alignment guide and body portion of an implant positioned in an intervertebral space according to an embodiment of the present disclosure; 
           [0017]      FIG. 6  is a lateral view illustration of the distractor portion, alignment guide and body portion of an implant positioned in an intervertebral space according to  FIG. 5 ; and 
           [0018]      FIG. 7  is an anterior view illustration of a distractor portion, alignment guide and body portion of an implant positioned in an intervertebral space according to an embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0019]    The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0020]    It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there are no intervening elements present. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0021]    In addition, spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
         [0022]    Well-known functions or constructions may not be described in detail for brevity and/or clarity. 
         [0023]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
         [0024]    Embodiments of the present invention are described with reference to the Figures. Now referring to  FIG. 1 , an interbody device  2  includes a distractor portion  10 , and a body portion  20  which may be coupled to each other. 
         [0025]    The distractor portion, or nosecone,  10  may be any distractor configured similar to distractors known to those skilled in the art. For example, distractor/nosecone portion  10  may have a wedge-shaped cross section as is known in the art. However, the distractor/nosecone  10  includes an opening or bore  14  formed in an end thereof for receiving an alignment guide  30 . Alternatively, the distractor/nosecone portion  10  may include an integral alignment guide  30  extending from a first end. Further, the distractor/nosecone portion  10  may include a mating element  12  configured to mate with a complementary mating element  22  of the body portion  20 . 
         [0026]    The distractor/nosecone portion  10  is operable to provide more precise placement of an implant due to its smaller size than a full implant. The alignment guide  30  extending from the distractor/nosecone  10  is easily manipulated by a surgeon to move the distractor/nosecone  10  to a desired location, such that the alignment guide  30  extending from the distractor/nosecone  10  is positioned to receive a subsequent, or body, portion  20  of an implant that can be slid along the alignment guide  30  to the desired position. 
         [0027]    Moreover, the distractor/nosecone portion  10  is operable to perform initial interbody distraction. No separate trial or distractor is required, leaving more operating space for a surgeon. The distractor/nosecone portion  10  may be left in place as part of an implant. The distractor/nosecone portion  10  provides posterior disc space (middle column) height and restoration/maintenance of foraminal volume (the volume or space of the foramina, or openings, which are present between every adjacent pair of vertebrae). 
         [0028]    In one embodiment, the distractor/nosecone  10  has a fixed size and shape. In other embodiments, the distractor/nosecone  10  is expandable. For example, the distractor/nosecone  10  may be expandable in vertical height to provide additional intervertebral volume and alignment. Further, it may be expandable or deploy a fixation mechanism to provide substantial anchoring or fixation to one or more vertebral endplate(s). Fixation may be achieved using screws, blades or the like. In one embodiment the expandable distractor/nosecone  10  is expandable and/or compressible independent of the other parts of the device to achieve desirable lordosis (inward curvature of the spine). 
         [0029]    In one or more embodiments, an expandable/compressible distractor/nosecone  10  may include opposing faces having an expanding element disposed therebetween, in the manner of lifts or jacks (such as but not limited to trolley jacks or scissor jacks) as known in the art. For example, a screw type expander provides the user with the ability to expand or collapse the distractor/nosecone  10 . In other embodiments a cam mechanism, or deployable spikes, may be employed to provide expansion/contraction. The distractor/nosecone portion  10  may be fixated to vertebral bodies, allowing for the body portion  20  to be mated to the distractor/nosecone portion  10  in a controlled fashion without impaction. 
         [0030]    The body portion  20  may be any implant device, such as but not limited to an intervertebral cage, arthroplasty device, biologic or nonbiologic delivery device, etc. Regardless of the configuration of the body portion  20 , it includes a bore  24  for receiving the alignment guide  30 . The bore  24  is positioned and configured to permit the body portion  20  to be slidably engaged on the alignment guide  30  and brought into contact with the distractor/nosecone portion  10 . The body portion  20  includes a complementary mating element  22  engageable with the mating element  12  of the distractor/nosecone portion  10 . The elements  10  and  12  facilitate engagement of the body portion  20  with the distractor/nosecone portion  10 . The mating elements  10  and  12  may take any suitable, known form, such as but not limited to Morse taper, mechanical interlock, magnetic connection, etc. 
         [0031]    The alignment guide  30  is a wire, rod or the like which may be integral with or removably attachable to the distractor/nosecone portion  10 . For example, the alignment guide may be threaded into the bore  14  of the distractor/nosecone portion  10 . The alignment guide  30  may have a circular cross section to permit rotation in the bore  24 . Alternatively, as shown in  FIG. 2 , the alignment guide  30  may have a non-circular cross section keyed to the cross section of the bore  24  to prevent unwanted rotation. The alignment guide  30  may be rigid or flexible, straight or curved, depending on the application, to permit better manipulation by the surgeon in the operating space. 
         [0032]    The placement and orientation of the alignment guide  30 , extending as it does from the distractor/nosecone portion  10 , is dependent on placement of the distractor/nosecone portion  10 . The alignment guide  30  provides for proper navigation alignment and stable positioning of the distractor/nosecone  10  and body portion  20  of the implant device  2 . 
         [0033]    The alignment guide  30  may also be used for ancillary implant construction such as but not limited to biologic or non-biologic delivery devices or implants, mechanical implants, rigid or non-rigid support devices, spacers, etc. 
         [0034]    In  FIGS. 3-7 , a series of placement steps are shown, viewed from both the front and side of the patient, illustrating the deployment of the device  2  within the patient. These placement steps can be generally outlined as follows. After disc space preparation, the distractor/nosecone portion  10 , and the alignment guide  30  are inserted and properly positioned in the interspace. The distractor/nosecone portion  10  may be manipulated by the surgeon using the alignment guide  30  to adjust the interspace. A handle  40  may be provided which is attachable to the alignment guide  30 , where the handle  40  offers better grip of and control over the alignment guide  30  and therefore better positioning of the distractor/nosecone portion  10 . The handle  40  may be made of any suitable material, including plastic, stainless steel, etc. The handle  40  may slide over the alignment guide  30 , or be threaded onto the alignment guide  30 , or attached in any other suitable fashion, as long as it is removable later to allow installation of the body portion  20 . In one embodiment, the handle  40  has a bore, the alignment guide  30  slides into the bore, and a set screw or other fastening device fixes the handle  40  firmly to the alignment guide  30  for as long as the handle  40  is needed for placement of the distractor/nosecone portion  10 . 
         [0035]    When the distractor/nosecone portion  10  is in position, the handle  40  is removed from the alignment guide  30 . With the distractor/nosecone portion  10  in place, appropriate disc height restoration can be confirmed. In addition, the length of the implant body portion  20  to be implanted may be measured by reference to markings on the alignment guide  30 , and the body portion  20  can be cut to the appropriate length before implantation. The implant body portion  20  is then translated along the alignment guide  30  and brought into close contact with the distractor/nosecone portion  10 . Fixation between the body portion  20  and the distractor/nosecone portion  10  may be through the use of Morse taper, mechanical interlock, etc. Moreover, the alignment guide  30  may be used for ancillary device implant portion fixation. 
         [0036]    The section of the alignment guide  30  which remains exposed after coupling the distractor/nosecone portion  10  and the body portion  20  may be removed by cutting the alignment guide  30  or by bending/breaking the alignment guide  30  at pre-established notches. In embodiments in which the alignment guide  30  is not integral with the distractor/nosecone portion  10 , the distractor/nosecone portion  10  may be withdrawn—either by simply pulling the alignment guide  30  out of the bore  14  if the bore  14  is smooth, or by unscrewing the alignment guide  30  from the bore  14  if the bore  14  is threaded. 
         [0037]    With further reference to  FIGS. 3-6 , an embodiment of the disclosed device  2  is shown in connection with an ALIF procedure. The ALIF (anterior) procedure is performed from the front of the patient, and may be used to correct the patient&#39;s lateral-view spinal curvature. With reference to  FIG. 3 , an anterior view shows positioning of the distractor/nosecone portion  10 , in a posterior interbody space between adjacent vertebrae  100  and  102 . The alignment guide  30  is visible in  FIG. 3 , but the handle  40  is omitted for clarity.  FIG. 4  is a lateral view of the same procedural step as in  FIG. 3  which shows reestablishment and/or maintenance of the posterior interbody height and foraminal volume with the distractor/nosecone portion  10  in place. The alignment guide  30  extends from the distractor/nosecone portion  10 , and the handle  40  is still in place on the alignment guide  30 . 
         [0038]    With reference to  FIGS. 5 and 6 , anterior and lateral views, respectively, of placement of the body portion  20  is shown. The body portion  20  of the device may be used to “dial in” lordosis (side-view spinal curvature) by adjusting the enforced angle between the vertebrae  100 / 102  while the posterior height is maintained. The body portion  20  of the device  2  may be wedge-shaped in order to facilitate establishment of the desired angle between the vertebrae  100 / 102  and achieve the desired lordosis. In another embodiment, the body portion  20  may be vertically expandable in order to facilitate establishment of the desired angle between the vertebrae  100 / 102  and achieve the desired lordosis. 
         [0039]    Now referring to  FIG. 7 , an embodiment of the disclosed device  2  is shown in connection with a LLIF procedure. The LLIF (lateral) procedure is performed from the side of the patient, and may be used to increase intervertebral space, to correct asymmetrical spinal curvature, or for spinal fusion. In an anterior (front) view, the distractor/nosecone portion  10  maintains the distal interbody height allowing for placement of the body portion  20  of the implant using the alignment guide  30  with markedly lessened risk of endplate damage as compared to conventional implants and procedures. The body portion  20  shown in  FIG. 7  has constant thickness, as opposed to the wedge-shaped body portion  20  of  FIG. 6 . 
         [0040]    As mentioned earlier, the alignment guide  30  may be fixed to the distractor/nosecone portion  10 , or may be removable from the distractor/nosecone portion  10 . Thus, in some embodiments, the alignment guide  30  is removed from the patient after the distractor/nosecone portion  10  and the body portion  20  have been placed, and in some embodiments, the alignment guide  30  remains inside the patient after the distractor/nosecone portion  10  and the body portion  20  have been placed. For embodiments where the alignment guide  30  remains inside the patient after the distractor/nosecone portion  10  and the body portion  20  have been placed between the vertebrae, it is advantageous to fix the body portion  20  to the alignment guide  30  in order to create a rigid assembly. Several different techniques are envisioned for fixing the body portion  20  to the alignment guide  30 . These techniques include bending the alignment guide  30  over around the external end of the body portion  20 , adding a locking collar over the alignment guide  30  up against the body portion  20 , and any other mechanical means of attachment. 
         [0041]    Although the devices and systems of the present disclosure have been described with reference to exemplary embodiments thereof, the present disclosure is not limited thereby. Indeed, the exemplary embodiments are implementations of the disclosed systems and methods are provided for illustrative and non-limitative purposes. Changes, modifications, enhancements and/or refinements to the disclosed systems and methods may be made without departing from the spirit or scope of the present disclosure. Accordingly, such changes, modifications, enhancements and/or refinements are encompassed within the scope of the present invention.