Abstract:
A system and method are provided that use a formable bone plate and a clamping apparatus for small bone reconstruction. The formable bone plate includes a plate body having a plurality of nodes separated by internodes. Each node includes a hole formed therein for receiving a screw, wire, tack, or other fixation device screwed or placed into a bone. A clamp engages an engagement section of the node to facilitate bending of at least one of the internodes to contour the plate to the bone in-situ or ex-situ and when at least partly screwed to or not screwed to the bone.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to the Provisional Patent Application No. 61/051,749, filed on May 9, 2008 and entitled “Formable Bone Plate, Clamping Apparatus, Osteotomy System And Method For Reconstructing A Bone”, which application is being incorporated herein, by reference, in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a formable bone plate, a clamping apparatus, an osteotomy system and a method for small bone reconstruction. Such a plate, apparatus, system and method provide a surgeon with implants and instruments necessary to perform reconstructive bone surgery (osteotomies and fusions) of the small bones of the upper extremity or other parts of the human body, which could eventually include wrist, hand, maxillofacial, foot and ankle surgery. 
     Description of the Related Art 
     Typical formable bone plates are formed of nodes that provide for screw or pin type of mechanical attachment to the bone and internodes or webs that provide an area more easily deformed, as well as, connection and structural support between nodes. 
     Some devices exist to form or shape plates, but some are difficult to use and/or don&#39;t give the surgeon optimal forming or shaping control. Ideally, to form the plate, it is optimal to rotate or torque a node in one or more of the X, Y or Z axis while at least one other node is held firmly in place and isolated from the bending forces. This is particularly important if the node that the surgeon wants to isolate has already been affixed to the bone with a screw; otherwise, the bending forces will transmit to the screw and potentially cause pull-out of the same or damage to the bone. In some existing devices and methods, such as disclosed by Huebner in U.S. Pat. No. 7,189,237 the bending forces are not applied at the node, but instead are applied at the internodes or webs. This approach does not fully isolate a node where a screw has been placed from the bending forces, since the node itself is not held firmly. In other existing devices, the node that the surgeon may want to isolate would be held in place by threading a tool or a tool accepting socket into that node. However, this becomes a practical impossibility if a screw has already been affixed to the bone in that node, because the screw occupies the space and the thread where the tool or the tool accepting socket would normally be threaded. That precludes the possibility of isolating a node that has already been affixed to the bone from bending forces. 
     BRIEF SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a formable bone plate, a node clamping apparatus, an osteotomy system and a method for reconstructing a bone, which overcome the above-mentioned disadvantages of the heretofore-known devices of this general type and which allow a user to easily shape osteotomy plates before, during or after affixing the plate to the bones, thus enabling an improved surgical procedure and a result that is superior to that possible with current devices. The clamping apparatus is intended to be used on the nodes of a plate according to the invention to facilitate optimum clamping. 
     The in-situ formable bone plates, node clamping apparatus and osteotomy system according to the invention are constructed in such a way that an appropriately constructed clamp can engage at least one node of the plate while the plate is affixed, partially affixed or not affixed, to the bone. In a preferred embodiment, the plate has a circumferential undercut around each node, where the undercut may or not extend along the internode portions. Correspondingly, in this embodiment, the clamp is constructed in such a way that it will first open, then be placed around a plate&#39;s node, and then closed to clamp circumferentially around the node, with a portion of the clamp extending under the undercut portion. This geometry permits secure fixation in all three X-Y-Z axes, permitting forming of the plate in any of these directions. The clamp may, optionally, have a “through hole” drilled through the center to serve as a drill guide during surgical procedures. In this configuration, the clamp is opened, placed around a node, and then clamped into place. Once clamped, the surgeon inserts a drill into the through hole of the clamp and proceeds to drill through the bone. The hole created by such drilling then serves as a pilot hole for a screw to be placed later. Additionally, the clamp of the instant embodiment is constructed to clamp around a node which may already have a screw affixing it to the bone. If desired, the clamp may have a recessed area in the corresponding region where the head of such a screw would normally be positioned when affixed to provide space relief and avoid interference of the screw head. An additional benefit of the presently described embodiment is that the smaller surface area of the plate, created by the undercut, may minimize tissue damage of the periosteum. It is believed that minimizing contact of plate to bone reduces the localized ischemia that may develop subsequent to plate application. Alternate embodiments include plate and clamp features that ensure clamping and three-axis articulation by other measures including usage of engagement holes and pins, and alternate configurations for circumferential clamping around the nodes. 
     The plates of the invention have the advantage of being easily formed by the surgeon to match the patient&#39;s anatomical circumstances before application, during application or after being partially or fully affixed in-situ. 
     Clamps made in accordance with an embodiment of the instant invention are constructed to mate with the plate geometry and selectively and securely hold nodes of a plate. In one particular method of the present invention, a first clamp is attached to a first node and, while holding it securely in position, a second clamp is attached to a second node and rotated in any, or all, of the X-Y-Z axes to form the plate into a desired configuration. Even in a case where the first node has been attached to the bone with a screw, the first clamp isolates the bending forces exerted by the rotation of the second clamp, preventing those forces from being translated to the screw and possibly causing pullout of the same and/or damage the bone. Therefore, using the system and method of the instant invention, it is possible to readjust the plate after screw application and to bend and contour the plate on each internode section during application. 
     In one particular embodiment of the instant invention, the plates are provided with “head” portions usually applied at the metaphysis or joint-end of the bone and “shaft” portions usually applied to the shaft of those bones. If desired, a “neck” portion can join the head and the shaft, for strength, but also for ease of shaping. Osteotomies and fusions are usually performed at the junction of the metaphysis with the shaft. The bendable internode sections and neck of the instant embodiment will allow the adjustment of the angle of correction after the plate has been completely applied. 
     The plates according to the invention have the capacity to be easily shaped ex-situ, that is, before application to the bone; and in-situ, that is, contoured to the bone during placement, and also allow a final correction to be made to their shape after they have been finally affixed to the bone. The plates also present the ability to accept compression, fixed angle and/or variable angle screws. 
     The plates according to a preferred embodiment of the invention are constructed to fit common reconstructive clinical needs and present dedicated deformable sections for correction adjustment. If desired, they may additionally have fixed angle K-wire holes for facilitating implant application or allow the use of K-Tacks for the same purpose. 
     The plates according to the invention come in basic shapes that allow the surgeon to easily cut them to length leaving a biologically acceptable cut surface. 
     If further desired, the plates according to the invention can also be provided with a step-compression/distraction mechanism to facilitate lengthening and shortening of bones. 
     Note that the plates according to the invention can be made in different sizes and shapes such as, but without being limited to, the examples enumerated below:
         1. Plates for radial and ulnar osteotomy using, for example, 3.5/2.5 mm screws for stepped compression-distraction with dedicated head portions and for carpal bone fixation for arthrodesis/ligament repair using arched and circular shapes and 2.5 mm screws.   2. Plates for metacarpal osteotomy using 2.5 mm screws, which are straight with a head portion.   3. Plates for phalangeal osteotomy using 2.0 mm screws, which are straight with a head portion.   4. Plates for a scaphoid reconstruction device.   5. Plates for a total wrist fusion device.       

     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a formable bone plate, a clamping apparatus, an osteotomy system and a method for reconstructing a bone, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a diagrammatic, top-plan view of a first embodiment of an in-situ formable bone plate according to the invention having undercuts on the bottom surface of the plate; 
         FIG. 2  is a perspective view of the bone plate shown in  FIG. 1 ; 
         FIG. 3  is a side-elevational view of the bone plate shown in  FIGS. 1 and 2 ; 
         FIG. 4  is an enlarged, cross-sectional view of the bone plate, taken along the line IV-IV of  FIG. 3 , in the direction of the arrows; 
         FIG. 5  is an enlarged, top-plan view of the bone plate shown in  FIGS. 1-4 ; 
         FIGS. 6A, 7A, 8A, 9A, 10A, 11A and 12A  are top-plan views of different nodes of the bone plate shown in  FIG. 5  and  FIGS. 6B, 7B, 8B, 9B, 10B, 11B and 12B  are respective cross-sectional views taken along the lines VI-VI to XII-XII of  FIGS. 6A, 7A, 8A, 9A, 10A, 11A and 12A , showing different embodiments of undercuts of the bone plate; 
         FIG. 13A  is a top-plan view of a second embodiment of an in-situ formable bone plate according to one particular embodiment of the invention having similar undercuts on the top surface and the bottom surface of the plate. 
         FIG. 13B  is a perspective view of the plate shown in  FIG. 13A . 
         FIG. 13C  is a cross-sectional view taken along the lines XIII of  FIG. 13A . 
         FIGS. 14A and 14B  are top-perspective and bottom-perspective views of the bone plate shown in  FIGS. 1-5 ; 
         FIG. 15  is a perspective view of a clamp fitted to a T-shaped bone plate with screws; 
         FIG. 16  is an enlarged, fragmentary, perspective view of a portion XVI of  FIG. 15 ; 
         FIGS. 17 and 18  are respective front-perspective and side-perspective views of the clamp fitted to the T-shaped bone plate having compression screws; 
         FIG. 19  is a longitudinal-sectional view taken along the line XIX-XIX of  FIG. 17 , in the direction of the arrows; 
         FIG. 20  is an enlarged, fragmentary, longitudinal-sectional view of a portion XX of  FIG. 19 ; 
         FIG. 21  is a side-elevational view of the bone plate and the clamp with a clamping tube removed; 
         FIG. 22  is an enlarged, fragmentary, end-elevational view of a portion XXII of  FIG. 21 ; 
         FIG. 23  is a longitudinal-sectional view taken along the line XXIII-XXIII of  FIG. 22 , in the direction of the arrows; 
         FIGS. 24 and 25  are respective side-elevational and front-elevational views of the clamp showing a drill guide thereof; 
         FIG. 26  is an enlarged, fragmentary, side-elevational view of a portion XXVI of  FIG. 24 ; 
         FIG. 27  is a longitudinal-sectional view taken along the line XXVII-XXVII of  FIG. 26 , in the direction of the arrows; 
         FIG. 28  is a perspective view of a T-shaped bone plate, compression screw and K-wire on a bone segment; 
         FIG. 29  is an enlarged, fragmentary, perspective view of a portion XXIX of  FIG. 28 ; 
         FIG. 30  is a side-elevational view of the K-wire; 
         FIG. 31  is a perspective view of the K-wire; 
         FIG. 32  is an enlarged, fragmentary, perspective view of a portion XXXII of  FIG. 31 ; 
         FIGS. 33, 34 and 35  are respective top-plan, side-elevational and perspective views of another embodiment of an in-situ formable bone plate according to the invention, having engagement holes; 
         FIG. 36  is an enlarged, fragmentary, perspective view of a portion XXXVI of  FIG. 35 ; 
         FIG. 37  is an enlarged, fragmentary, side-elevational view of a portion XXXVII of  FIG. 34 ; 
         FIG. 37  is an enlarged, fragmentary, side-elevational view of a portion XXXVII of  FIG. 34 ; 
         FIG. 38  is a cross-sectional view taken along the line XXXVIII-XXXVIII of  FIG. 37 , in the direction of the arrows; 
         FIGS. 39 and 40  are respective side-elevational and front-elevational views of a further embodiment of a clamp in accordance with the present invention having engagement pins; 
         FIG. 41  is an enlarged, fragmentary, perspective view of the clamp of  FIGS. 39 and 40 ; 
         FIG. 42  is an enlarged, fragmentary, perspective view of the clamp of  FIGS. 39-41  engaging the bone plate of  FIGS. 33-38 ; 
         FIG. 43  is a perspective view of the clamp and bone plate of  FIG. 42 ; 
         FIG. 44  is a fragmentary, perspective view of a portion XXXXIV of  FIG. 43 , showing the engagement pins and holes; and 
         FIG. 45  is a perspective view of a further embodiment of the instant invention including clamps where the jaws are built into the distal end of a pliers. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures of the drawings in detail and first, particularly, to  FIGS. 1-4  thereof, there is seen a first embodiment of a bone plate  1  according to one particular embodiment of the invention, having a plate body with seven nodes  2  and webs or internodes  3 , therebetween. However, this is not meant to be limiting, as the bone plate  1  may have more or fewer than seven nodes, as desired, and may be linear, T-shaped, L-shaped, Y-shaped, arched, curved or any combination of shapes, as will be discussed further below. The nodes  2  each have an inner surface  4 , which can be spherical, aspherical, frustoconical, cylindrical or any other geometric shape as required for seating or engaging the complementarily shaped head of a screw, surrounding a hole  5  for permitting passage of the shaft of a screw  23 , as is best seen in  FIGS. 15 and 16 . Each node  2  also has a clamp engagement section  6 , as will be discussed further below. 
       FIG. 5  shows a bone plate  1 ′ with nodes  2  and internodes or webs  3 , while  FIGS. 6A to 12B  each show a possible form of a node  2  of the bone plate  1 ′ in respective top-plan and cross-sectional views. More specifically,  FIGS. 6A and 6B  show a node  2  without an engagement section, for purposes of comparison.  FIGS. 7A and 7B  show a node  2  with an engagement section in the form of an annular or circumferential step  10 .  FIGS. 8A and 8B  show a node  2  with an engagement section in the form of two radial blind holes  11 .  FIGS. 9A and 9B  show a node  2  with an engagement section in the form of four oblique blind engagement holes  12 .  FIGS. 10A and 10B  show a node  2  with an engagement section in the form of a concave annular or circumferential V-shaped radial recess  13 .  FIGS. 11A and 11B  show a node  2  with an engagement section in the form of two L-shaped undercuts  14 .  FIGS. 12A and 12B  show a node  2  with an engagement section in the form of frustum surface  15  of a cone. It is noted in this regard that the engagement section with the engagement holes  12  shown in  FIGS. 9A and 9B  are intended to cooperate with a clamp  40  designed in accordance with one particular embodiment of the invention discussed below. It must also be understood that more than one, or even all, of the nodes may have engagement sections. The node configurations  2  of the plate  1 ′ shown in  FIGS. 6A-12A  are examples of possible node configurations consistent with the present invention. However, it can be seen from the foregoing that additional node configurations and geometries are possible for the nodes  2 , while still remaining within the scope of the instant invention. 
       FIGS. 13A and 13B  show a second embodiment of bone plate  1  with nodes  2  and internodes or webs  3 , inner surface  4 , which can be spherical, aspherical, frusto-conical, cylindrical or any other geometric shape as required for seating or engaging the complementarily shaped head of a screw, surrounding a circular hole  5  or elongated slot  5 ′ for permitting passage of the shaft of a screw.  FIG. 13C  shows a cross section of a node  2  with an engagement section conformed by a convex annular or circumferential V-shaped radial projection  16 . The engagement section is symmetrical which allows the plate to be used with its upper or lower surface, indistinctly, adjacent to the bone. 
       FIGS. 14A and 14B  are respective top and bottom perspective views of a bone plate  1  according to one particular embodiment of the invention, having the nodes  2 , the internodes  3 , the inner surfaces  4  and the screw holes  5 . The plate  1  can have a variety of shapes and/or geometries in accordance with the instant invention. For example, a T-shaped bone plate  21  having a leg  21 ′, a crosspiece  21 ″ and nodes  2 , is shown in  FIG. 15 . Referring now to  FIG. 15 , it may be seen that a clamp  20  in accordance with one embodiment of the instant invention is placed over, and engages with, a node  2 , thus receiving a head  22  of a screw  23  passing through a hole  5  in one of the nodes  2 . From  FIG. 16  it can be seen that the head of each screw  23  has a socket  24 . The sockets  24  have polygonal, for example hexagonal, hexalobular or multilobular, surfaces for receiving a driver, wrench or screwdriver for tightening and loosening the screws.  FIGS. 15 and 16  also show that the present particular embodiment of the clamp  20  has clamping jaws  26 ,  27  engaging the bone plate  21  and a clamping tube  28  sliding over and holding the clamping jaws  26 ,  27  in place. The clamping jaws  26 ,  27  each have a respective relief  26 ′,  27 ′ and the clamping tube  28  has a drill guide hole  29  and a handle  30 . The drill guide hole  29  continues through the clamping jaws  26 ,  27  to permit drill access to the bone as seen in  FIGS. 19 and 20 . 
       FIGS. 17 and 18  respectively show the clamp  20  from the side of the T-shaped bone plate  21  and from the end of the T-shaped bone plate  21 , screwed into a bone  32  by the screws  23 . Screws  23  may be compression screws, fixed angle and/or variable angle screws, as desired.  FIG. 19  is a cross section that shows the clamping tube  28  and the handle  30  and  FIGS. 19 and 20  show the drill guide hole  29  and illustrate how the jaws  26 ,  27  engage the node  2  receiving the head  22  of screw  23 . 
       FIGS. 21 and 22  show a side view elevation of one of the clamping jaws  26  with relief  26 ′ disposed over a node  2  of the bone plate  21 .  FIG. 23 , in a manner similar to  FIG. 20 , shows how the clamping jaws  26 ,  27  engage a node  2  nested therein by gripping the annular or circumferential step  10  of the engagement section shown in  FIGS. 7A and 7B . In  FIGS. 24 and 25  the clamp locking features  35 ,  36  on both sides of the drill guide hole  29  are intended to assist in aligning the two parts as they come together and prevent the clamping jaws from sliding apart once clamped. The locking features may also be accomplished with holes and pins. A socket  31 , shaped to engage a node  2  is nested in the step  10 , is additionally seen in  FIGS. 26 and 27 . The socket may include a screw head relief  31 ′ to avoid interference of a screw head and permit proper engagement of socket  31  into node  2  if a screw has been placed in that node. 
     Referring to  FIGS. 19, 20, 23, 24, 25, 26 and 27 , a clamp  20  is used by placing jaws  26 ,  27  having lower ends with sockets  31  that are complementary to one of the engagement sections  10 ,  11 ,  13 ,  14 ,  15 ,  16  shown in  FIGS. 7B-12B  and  FIG. 13C  around a node  2 , so as to engage the engagement section. The clamping tube  28  of  FIG. 18  is then slid over the jaws to lock them in place by aligning locking features  35 ,  36 . Alternatively, as seen in  FIG. 45  the clamping jaws  26 ,  27  may be implemented as the distal jaws of pliers  50  which are locked in place by the action of compressing the proximal handles of the pliers  50 . 
       FIG. 28  shows a K-wire or Kirschner wire  38  inserted through a node  2  of the bone plate  21  into a bone  32  as a temporary anchor, as well as a screw  23 , for example, a compression screw, attaching the bone plate to the bone. The K-wire  38  is shown in side and oblique-elevational views in  FIGS. 30 and 31  and the enlarged illustration of  FIG. 32  shows that a button  39  is attached to the K-wire  38  and a self-drilling tip  37  is formed at the end of the K-wire. As is seen in  FIG. 29 , the button  39  fits the contour of surface  4  while allowing a portion of the K-wire  38  to pass through the hole  5 . The button  39  is intended to prevent the K-wire  38  from penetrating the bone more than necessary for achieving temporary anchoring. 
     A further embodiment of the bone plate and clamp of the present invention is illustrated in  FIGS. 33-44 . In contrast to the previously described embodiments of the invention, which use a clamp  20  having sockets  31  matching engagement sections  10 ,  11 ,  13 ,  14 ,  15  and  16  at the lower surface or lateral surface of a plate  1 ,  21 , the presently described embodiment uses a clamp  40  having engagement pins  42 ,  43  that engage the four oblique blind engagement holes  12  of the plate. See also, for example, engagement holes  12  of the engagement section shown in  FIGS. 9A and 9B . 
     More specifically,  FIGS. 33, 34, 35 and 36  show a bone plate  41  having a plate body with nodes  2  including the oblique blind engagement holes  12  and internodes or webs  3  between the nodes  2 . The nodes  2  each have an inner surface  4  surrounding a hole  5  for accepting a screw. The actual oblique direction of the engagement holes  12  is best seen in the cross-sectional views of  FIGS. 37 and 38 . 
     Referring now to  FIGS. 43 and 44 , the clamp  40  once again has two clamping jaws  46 ,  47  surrounding a drill guide hole  49  and the engagement pins  42 ,  43  protruding from the clamping jaws, as is better seen in  FIGS. 39, 40, 41 and 42 .  FIGS. 43 and 44  illustrate how the engagement pins  42 ,  43  of each clamping jaw  46 ,  47  of the clamp  40  engage the oblique engagement holes  12  in a node  2  of the bone plate  41 . The clamping tube  28  of  FIGS. 17, 18 and 19 , which for simplicity is not illustrated in  FIGS. 33-44 , is slid over the clamping jaws  46 ,  47  to lock them in place, after placing the engagement pins  42 ,  43  in the engagement holes  12  of a node  2 . As additionally described in connection with the other embodiments, the clamping jaws  46 ,  47  of the present embodiment may be implemented by the distal jaws of pliers  50  which are locked into place by compressive action on the proximal pliers handles, as shown more particularly in  FIG. 45 . 
     Referring now to  FIGS. 1-45 , a system of the invention operates as follows: A clamp  20 ,  40 ,  50  can engage the plate  1 ,  1 ′,  21 ,  41  while the plate is affixed, partially affixed or not affixed at all to the bone. A first clamp  20 ,  40 ,  50  is opened, then placed circumferentially around a node, with a portion of the clamp extending under the undercut portion or surface or into the lateral recesses or holes or with the engagement pins into the engagement holes. This secures the first node  2  assuring that any bending forces created by rotating or torqueing will be transmitted to the first clamp  20 ,  40 ,  50 , shielding any screw  23  which may be present at the first node  2  from these forces, thereby prohibiting screw ‘pull-out’. Then, a second clamp  20 ,  40 ,  50  is opened and secured in a similar way to a second node  2 . Rotating or torqueing the second clamp generates bending forces which cause bending or formation of the plate in the direction of any of the X, Y, and/or Z axes. 
     In particular embodiments of the invention, a drill guide hole  29 ,  49  in the center of the clamp  20 ,  40  serves as a drill guide during surgical procedures. After a clamp  20 ,  40  has been clamped into place, the surgeon inserts a drill into the guide hole  29 ,  49  of the clamp  20 ,  40  and proceeds to drill through the bone. The hole created by such drilling then serves as a pilot hole for a screw  23  to be placed later. Additionally, the clamp  20 ,  40 ,  50  is constructed to clamp around a node  2  which may already have a screw  23  affixing it to the bone. The plates  1 ,  1 ′,  21 ,  41  of the invention have the advantage of being able to be formed by the surgeon to match the patient&#39;s anatomical circumstances before application, during application or after being partially or fully affixed in-situ. The clamps  20 ,  40 ,  50  of the invention are constructed to mate with the plate geometry and selectively and securely hold the nodes  2  of a plate. Bending the plate  1 ,  1 ′,  21 ,  41  with a clamp  20 ,  40 ,  50  while another clamp  20 ,  40 ,  50  is attached and held in position firmly at a node  2  isolates the bending forces preventing them from being translated to the screws  23 . It is possible to readjust sections of the plate  1 ,  1 ′,  21 ,  41  after screw application and to bend and contour the plate at each internode section  3  during application. The bending internode sections of the plates of the instant invention allow the adjustment of the angle of correction even after the plate has been completely applied. The plates, made in accordance with the instant invention can be easily shaped in-situ, that is, contoured to the bone during placement, and a final correction can be made after they have been finally attached to the bone with screws. Thus, the plates of the invention present the ability to accept compression, fixed angle and/or variable angle screws. The plates fit common reconstructive clinical needs and present dedicated deformable sections for correction adjustment. Additionally, as described herein, holes may be included for K-wires, to facilitate implant application and allow the use of K-Tacks with limiting buttons, for the same purpose.