Abstract:
Systems, methods, and kits incorporate a fusion member for vertebral processes. The fusion member may be unitary or modular. The fusion member comprises extensions configured to be crimped to vertebral processes. The extensions may comprise tabs configured to be deformed to further penetrate the vertebral processes. The tabs may also lock together modular components of the fusion member. The fusion member may comprise fasteners extending between the extensions. The fusion member may comprise a cage with a movable cover or a graft retention feature.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Application No. 61/219,687, filed Jun. 23, 2009, entitled BONE TISSUE CLAMP, which is pending. 
     The above-referenced document is hereby incorporated by reference in its entirety. 
     This application incorporates by reference each of the following applications in its entirety:
     U.S. Provisional Patent Application 61/017,336, filed Dec. 28, 2007, entitled BONE TISSUE CLAMP, which is expired;   U.S. Provisional Patent Application 61/023,327, filed Jan. 24, 2008, entitled BONE TISSUE CLAMP, which is expired;   U.S. Provisional Patent Application 61/104,199, filed Oct. 9, 2008, entitled BONE TISSUE CLAMP, which is expired;   U.S. Provisional Patent Application 61/108,368, filed Oct. 24, 2008, entitled BONE TISSUE CLAMP, which is expired;   International Patent Application No. PCT/US2008/088196, filed Dec. 23, 2008, entitled BONE TISSUE FIXATION DEVICE AND METHOD, which is pending; and   U.S. patent application Ser. No. 12/342,816, filed Dec. 23, 2008, entitled BONE TISSUE FIXATION DEVICE AND METHOD, which is pending.   

    
    
     BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     Exemplary embodiments of the present disclosure comprise a device that can be secured to bone tissue and methods of securing the devices. In specific exemplary embodiments, a device may be secured to spinous processes of vertebral bodies. In other exemplary embodiments, a device may be secured to a calvarial flap or other bone tissue. 
     2. Description of Related Art 
     The pedicle screw is a common medical device currently used to attach components to a patient&#39;s vertebrae. While providing a stable platform to attach components to vertebrae, the pedicle screw has inherent drawbacks in its use. Such drawbacks include the difficulty in accessing the portion of the vertebrae needed to insert the pedicle screw. In addition, there are risks of serious injuries to the patient when using a pedicle screw to penetrate a vertebra in a region close to the nerves of the spinal cord. 
     Systems and methods for treatment for various spinal conditions have been disclosed in U.S. Pat. Nos. 5,645,599 and 6,440,169, incorporated herein by reference. Additional systems and methods of treatment have been disclosed in “Interspinous Process Decompression for Neurogenic Intermittent Claudication Secondary to Degenerative Lumbar Spinal Stenosis”, Global Surgery—Future Directions 2005 by Patrick Simons, also incorporated herein by reference. 
     SUMMARY OF THE INVENTION 
     Exemplary embodiments of the present disclosure provide novel systems, kits, and methods for securing medical devices to bones for use in treatment of spinal conditions and other medical conditions where securement to bone tissue is needed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While exemplary embodiments of the present invention have been shown and described in detail below, it will be clear to the person skilled in the art that changes and modifications may be made without departing from the scope of the invention. As such, that which is set forth in the following description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled. 
       In addition, one of ordinary skill in the art will appreciate upon reading and understanding this disclosure that other variations for the invention described herein can be included within the scope of the present invention. For example, different materials of construction may be used for the insert employed in the kit or system. Furthermore, the shape of insert may also be altered. 
       In the following Detailed Description, various features are grouped together in several embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that exemplary embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. 
       Identical reference numerals do not necessarily indicate an identical structure. Rather, the same reference numeral may be used to indicate a similar feature or a feature with similar functionality. Not every feature of each embodiment is labeled in every figure in which that embodiment appears, in order to keep the figures clear. Similar reference numbers (e.g., those that are identical except for the first numeral) are used to indicate similar features in different embodiments. 
         FIG. 1  is a first upper perspective view of a fusion member according to a first exemplary embodiment of the present disclosure; 
         FIG. 2  is an upper perspective view of the embodiment of  FIG. 6 ; 
         FIG. 3  is a lower perspective view of the embodiment of  FIG. 1 ; 
         FIG. 4  is an upper view of the embodiment of  FIG. 1  in an installed position; 
         FIG. 5  is an upper perspective view of the embodiment of  FIG. 1  in an installed position; 
         FIG. 6  is an upper perspective view of a fusion member according to a second exemplary embodiment of the present disclosure; 
         FIG. 7  is an upper perspective view of a fusion member according to a third exemplary embodiment of the present disclosure; 
         FIG. 8  is a lower perspective view of the embodiment of  FIG. 7 ; 
         FIG. 9  is an upper perspective view of the embodiment of  FIG. 7  in an installed position; 
         FIG. 10  is an side view of the embodiment of  FIG. 7  in an installed position; 
         FIG. 11  is an upper perspective view of a fusion member according to a fourth exemplary embodiment of the present disclosure; 
         FIG. 12  is an upper view of the embodiment of  FIG. 11  in an installed position; 
         FIG. 13  is an upper perspective view of a fusion member according to a fifth exemplary embodiment of the present disclosure; 
         FIG. 14  is an upper perspective view of a fusion member according to a sixth exemplary embodiment of the present disclosure; 
         FIG. 15  is a lower perspective view of the embodiment of  FIG. 14 ; 
         FIG. 16  is an upper perspective view of a fusion member according to a seventh exemplary embodiment of the present disclosure; and 
         FIG. 17  is a lower perspective view of the embodiment of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     Standard medical planes of reference and descriptive terminology are employed in this specification. A sagittal plane divides a body into right and left portions. A mid-sagittal plane divides the body into equal right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions. Anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. 
     Referring initially to FIGS.  1  and  3 - 5 , an exemplary embodiment of a fusion member  100  comprises a cage  115  defining an inner volume  110  and paired extensions  120  and  130  extending from cage  115 .  FIGS. 4 and 5  illustrate fusion member  100  installed between a pair of spinous processes  210  and  220 . As shown in  FIG. 4 , fusion member  100  generally forms an “H” shape in a posterior view, with extensions  120  forming ascending legs of the “H” shape and extensions  130  forming descending legs of the “H” shape. As used herein, the term “fusion member” is used to describe a member configured to promote fusion of vertebral processes. 
     In the embodiment shown, extensions  120  and  130  are configured so that they can be crimped (e.g, plastically deformed) onto spinous processes  210  and  220 . Extensions  120  and  130  comprise gripping members  121  and  131 , respectively, which assist in clamping fusion member  100  to spinous processes  210  and  220 . The cage  115  may comprise gripping members  135  located between extensions  120  and  130 . 
     Gripping members  121  and  131  allow fusion member  100  to be installed from a posterior direction so that extensions  120  and  130  can slide anteriorly along the sides of spinous processes  210  and  220 . After fusion member  100  has been properly located between spinous processes  210  and  220 , extensions  120  and  130  can be deformed so that gripping members  121  and  131  engage spinous processes  210  and  220 . Specifically, extensions  120  can be crimped or deformed so that they are pinched toward each other so that gripping members  121  sink into spinous process  220 . Similarly, extensions  130  can be crimped or deformed so that they are pinched toward each other to engage spinous process  210 . 
     In this exemplary embodiment, gripping members  121 ,  131 , and  135  are configured as sharp angled projections (e.g., teeth). In certain embodiments, gripping members  121 ,  131 , and  135  may be configured as prongs, tines, tabs, barbs or spikes. In the embodiment shown, gripping members  121  and  131  are angled so that the projections point towards cage  115 . Gripping members  121  and  131  are configured to allow translation between the fusion member  100  and a spinous process if the fusion member  100  is moved toward the engaged spinous process. This configuration restricts translation of the fusion member  100  in a direction away from the engaged spinous process. In the embodiment shown, gripping members  135  are pointed superiorly and inferiorly, and are configured to prevent translation in the posterior direction between the fusion member  100  and spinous processes  210  and  220 . 
     Extensions  120  and  130  also comprise tabs  122  and  132 , respectively, which assist in maintaining a fixed engagement between fusion member  100  and spinous processes  210  and  220 . In certain embodiments, tabs  122  and  132  may be formed by removing material from extensions  120  and  130  in a pattern that forms tabs  122  and  132 . 
     As shown in FIGS.  1  and  3 - 5 , tabs  122  and  132  are in an undeformed condition wherein tabs  122  and  132  are parallel to extensions  120  and  130 . After fusion member  100  is inserted between spinous processes  210  and  220 , tabs  122  and  132  may be deformed (e.g., plastically deformed inward toward the space between extensions  120  and  130 ) so that tabs  122  and  132  further engage spinous processes  210  and  220 . Tabs  122  and  132  may be deformed with a tool (e.g., forceps or a plier-type device, not shown) that comprise projections configured to engage tabs  122  and  132  and leverage members to provide easier deformation of the tabs. Tabs  122 ,  132  and gripping members  121 ,  131  serve to provide a positive engagement of fusion member  100  to spinous processes  210  and  220 . In certain embodiments, fusion member  100  can provide fixation of spinous processes  210  and  220 . 
     Cage  115  is shown in this embodiment to comprise a first end  116 , a second end  118 , a first side  117  and a second side  119 . Cage  115  also comprise a lower surface  129 , or lower cover, extending between first and second ends  116 ,  118  and first and second sides  117 ,  119 . As explained in more detail below, lower surface  129  can assist in retaining bone fragments inserted into inner volume  110 . 
     A plurality of bone fragments  145  (only a portion of which are shown in  FIGS. 4 and 5 ) may be disposed within inner volume  110  to assist in fusing spinous processes  210  and  220  together. Cage  115  comprises a plurality of apertures  125  to promote fusion of the bone fragments  145  and spinous processes  210  and  220 . In the exemplary embodiment shown, bone fragments  145  may be used to assist in inter-spinous process fusion. In other embodiments, bone fragments  145  may be used to assist in fusing various locations of adjacent vertebrae, including for example, inter-laminar fusion, facet fusion, inter-transverse process fusion, and inter-discal fusion. Bone fragments  145  may be of various sizes and shapes and may comprise bone autograft, allograft, or synthetic bone. 
     In the exemplary embodiment shown, extensions  120  comprise a recessed portion  123  in the area distal from cage  115 . Extensions  130  comprise projections  133  in the area distal from cage  115 . In certain embodiments, it may be desirable to utilize more than one fusion member  100 . In such embodiments, the fusion members  100  can be arranged so that projections  133  fit into recessed portions  123 . This can allow for closer spacing of fusion members  100 . 
     Referring now to  FIGS. 2 and 6 , another embodiment of a fusion member  101  is equivalent to fusion member  100  shown and described above in FIGS.  1  and  3 - 5 . Fusion member  101 , however, does not comprise a lower surface  129 . Still other exemplary embodiments may comprise a design similar to fusion member  100  with an additional upper surface, or upper cover, opposite of lower surface  129  to form a cage  115  that completely encloses the interior volume  110 . The upper surface may be movable or installable to provide at least temporary access to the interior volume  110 . 
     Referring now to  FIGS. 7-10 , an exemplary embodiment comprises a multi-piece fusion member  200 . In this embodiment fusion member  200  comprises four separate components that can be assembled to form a unit that functions similar to previously-described fusion member  100 . Fusion member  200  comprises a first clamping member  201 , a second clamping member  202 , a first plate  203 , and a second plate  204 . First plate  203  comprises a plurality of tabs  223  and second plate  204  comprises a plurality of tabs  233 . When deformed, tabs  223  and  233  are configured to extend through slots  224  in first and second clamping members  201  and  202 , respectively, and engage spinous processes  310  and  320  (shown in  FIGS. 9 and 10 ). This configuration allows for first and second plates  203 ,  204  to remain coupled to first and second clamping members  201  and  202 . First and second plates  203 ,  204  and first and second clamping members  201  and  202  may also comprise coupling or receiving members (not shown) including without limitation, threaded members, pins, eyelets, etc. 
     First clamping member  201  comprises a first end  216  and second clamping member comprises a second end  218 . First end  216 , second end  218 , and the central portions of first plate  203  and second plate  204  combine to form a cage  215  defining an inner volume  210 . Second plate  204  comprises a lower surface  229  (clearly visible in  FIG. 8 ) configured to extend towards first plate  203 . Lower surface  229  functions similar to previously described lower surface  129  of fusion member  100  and can serve to retain bone fragments  145  (not shown). 
     Referring now to  FIGS. 11-12 , another exemplary embodiment comprises a multi-piece fusion member  300  that is generally equivalent to the embodiment shown and described in  FIGS. 7-10 . This embodiment, however does not comprise a lower surface similar to lower surface  229  of the embodiment in  FIGS. 7-10 . As shown in  FIG. 12 , fusion member  300  is viewed from above in an installed position. Fusion member  300  is generally “H”-shaped when viewed from above. 
     Referring now to  FIG. 13 , another exemplary embodiment comprises a fusion member  400  similar to the one shown and described in FIGS.  1  and  3 - 5 . This embodiment also comprises fastening members  490  configured to extend through first end  416  and second end  418  of cage  415 . Fastening members  490  may comprise nails, screws, spikes, barbs, etc., and are configured to engage a spinous process inserted between extensions  420  and  430 . Fastening members  490  can provide fixation of the fusion member  400  to the spinous processes in addition to that provided by gripping members  421  and  431  and tabs  422  and  432 . Fastening member  490  may be preferentially positioned along a mid-sagittal plane bisecting the spinous process. 
     Referring now to  FIGS. 14 and 15  another exemplary embodiment comprises a fusion member  500  similar to the one shown and described in  FIG. 13 . This embodiment comprises a septum or rib  501  extending between first end  516  and second end  518  of cage  515 . Rib  501  can serve to provide structural rigidity to fusion member  500 . 
     Referring now to  FIGS. 16 and 17  another exemplary embodiment comprises a fusion member  600  similar to the one shown and described in  FIGS. 14 and 15 . This embodiment comprises a septum or rib  601  extending between first end  616  and second end  618  of cage  615 . Rib  601  can serve to provide structural rigidity to fusion member  600 . Rib  601  also comprises a receiving or securing feature  602 . In the embodiment shown, securing feature  602  comprises a notch, but other exemplary embodiments may comprise different configurations, including for example, a pin, a hook, a spike, a barb, etc. Securing feature  602  can be configured to secure, for example, a shaped bone block (not shown) configured for insertion into cage  615 . 
     Fusion members according to exemplary embodiments may be manufactured from suitable medical-grade materials, including, but not limited to, titanium and stainless steel. 
     It should be understood that the present system, kits, apparatuses, and methods are not intended to be limited to the particular forms disclosed. Rather, they are to cover all modifications, equivalents, and alternatives falling within the scope of the claims. 
     The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively. 
     The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. 
     The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed. 
     In the foregoing Detailed Description, various features are grouped together in several embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.