Abstract:
An in-series, dual locking mechanism device for securing at least one implant having a clamp, a locking mechanism and a bone fastener. The clamp is configured to include a channel for receiving the implant and a locking mechanism. The locking mechanism is structured to secure the implant within the clamp by applying a force in at least two locations that are configured to be adjacent and in-series relative to each other. The locking mechanism functions to reduce the resultant internal stresses realized by the implant that may lead to implant fracture or fatigue. The implant is generally continuous and is preferably rod shaped. The shape of the implant thereby allowing it to be utilized in various surgical procedural applications. The clamp is further configured for the attachment of a bone fastener. The bone fastener functioning to rigidly fix the clamp to the bone.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to implantable, surgical devices and, in particular, to an improved locking mechanism device resulting in the reduction of internal stresses to an implant.  
       BACKGROUND OF INVENTION  
       [0002]     Post-operatively, implanted medical devices may fail by sudden fracture or cyclic fatigue of one of the components that comprise the medical device. Failures of medical devices in vivo may be caused by numerous possible events or combination of events. These events may include, improper sizing of device, incorrect alignment of the device, a manufacturing defect within the device, improper materials being used to manufacture the device, use of the device in a contraindicative clinical setting, improper device design, resultant in vivo forces being applied that exceed the design limitations of the device, the device being subject to abnormal motion patterns and loss of device integrity.  
         [0003]     Decreasing resultant stresses realized within the components of a medical device post-operatively is critical to reducing the possibility of latent failures when certain construct materials are used. Currently, many locking mechanisms induce failure within an implant because of high stress concentrations resulting from single point loading configurations. The invention described herein addresses the failure modality that is seen at single point component securement interfaces by distributing a locking force over a larger implant contact area and thereby reducing the stress concentrations seen within an implant.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention provides an in-series, dual locking mechanism device for use in securing implants within an orthopaedic device. The purpose of the invention is to provide a mechanism for locking an implant in a fixed position in a manner such that the internal stresses realized by the implant are reduced. It is understood that the drawings and specific language used herein is for the purposes of promoting and understanding of the principles of the invention and that no limitation of the scope of the invention is thereby intended. Any alteration or modification to the drawings illustrated, and further application of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0005]     In meeting this design objective, the in-series, dual locking mechanism device may be comprised of a clamp that may include a channel in which an elongate and continuous implant is placed. The clamp may be further configured to include a locking mechanism that secures the placed implant in a fixed location. The locking mechanism being operable between an open position wherein the implant is free to move and a closed position wherein the implant is rigidly fixed in the clamp. In the closed position, the locking mechanism is structured to apply a pressing force to the implant in at least two adjacent and in-series locations. The clamp is configured to be attached to a bone by a bone fastener that is fixed to and projects from the clamp.  
         [0006]     The channel within the clamp is typically U-shaped, defined by a floor and at least two parallel side walls that project in an upward direction from the floor. The clamp may be configured in an alternative form including, but not limited to a cylinder or a bracket. Located on the side walls&#39; inner surfaces may be threads or an internal cam surface. The locking mechanism is preferably comprised of at least two locking caps that maybe constructed with external threads or a corresponding external cam surface. When in the closed position, the locking caps are inserted into the threads or the internal cam mechanism located on the side walls of the channel and are rotated until making contact with the inserted implant that lies on the floor of the channel, thereby holding the implant in position.  
         [0007]     The clamp can be configured to be joined with a bone fastener. Preferably, the bone fastener is inserted into a through hole in the floor of the channel, though alternatively, the bone fastener may be integrally attached to the clamp. The bone fastener may then project from the clamp engaging a bone. Depending upon the bone location, alternative bone fasteners may be used. These alternative bone fasteners include, but are not limited to pedicle bone screws, bone fixation posts, staples, hooks, anchors, fixed head screws, moveable head screws and collared dual threaded combination post/screws.  
         [0008]     The in-series, dual locking mechanism device rigidly secures an implant in a fixed position within a channel. Preferably, the implant is shaped as an elongate and continuous rod. Alternative implants may be utilized in the device including, but not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. The material comprising the implant is preferably selected from the group consisting of stainless steel, carbon fiber composite, titanium, cobalt-chromium, shape memory metal, resorbable polymers, bio-inert metal, bio-inert polymeric materials, and any combinations of these materials.  
         [0009]     The preferred embodiment of the in-series, dual locking mechanism device is used to secure an implant to a bone. Typically, the device is comprised of a clamp that includes at least one channel in which an implant is placed, a locking mechanism that is preferably integrally associated with the clamp and secures the implant, and a bone fastener that is attached to the clamp. The method of using the in-series, dual locking mechanism device can include the steps of: 1) selecting the preferred bone fastener from the kit and attaching it to the clamp; 2) drilling a pilot hole into at least one bone; 3) inserting the bone fastener into the pilot hole and fixing the clamp to the outer surface of the bone; 4) placing the implant within the channel; and 5) locking the implant into the clamp by engaging the locking mechanism into the closed position.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The features and advantages of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, which drawings illustrate several embodiments of the invention.  
         [0011]      FIG. 1  is a perspective view of the device;  
         [0012]      FIG. 2  is a perspective view of the clamp;  
         [0013]      FIG. 3  is a top plan view of the device;  
         [0014]      FIG. 4  is a perspective view of an alternative embodiment of the device;  
         [0015]      FIG. 5  is an exploded view of the device of  FIG. 4 ;  
         [0016]      FIG. 6  is a top plan view of the device of  FIG. 4 ;  
         [0017]      FIG. 7  is a perspective view of another alternative embodiment of the device;  
         [0018]      FIG. 8  is an exploded view of the device of  FIG. 7 ;  
         [0019]      FIG. 9  is a side elevation of the device of  FIG. 7  before closing the locking mechanism;  
         [0020]      FIG. 10  is a side elevation of the device of  FIG. 7  after closing the locking mechanism;  
         [0021]      FIG. 11  is a top plan view of the device of  FIG. 7 ;  
         [0022]      FIG. 12  is a sectional view along line  12 - 12  of the device of  FIG. 7 ;  
         [0023]      FIG. 13  is an exploded view of the collared bone fastener and locking nut;  
         [0024]      FIG. 14  is a perspective view of the clamp;  
         [0025]      FIG. 15  is a perspective view of another alternative embodiment of the device;  
         [0026]      FIG. 16  is a top plan view of the device of  FIG. 15 ; and  
         [0027]      FIG. 17  is a top plan view of the device of  FIG. 15 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     Locking mechanism devices are utilized to secure implants in a fixed position following final alignment placement. The in-series, dual locking mechanism device includes a clamp wherein the implant is placed, a locking mechanism for securing the implant and a bone fastener for securing the clamp to a bone. Each of the devices described include a locking mechanism that is constructed to engage and fixate the implant in two locations that are adjacent or in relative close proximity to each other and are arranged in a straight line or in-series with no offset deviation relative to each other. The in-series, dual locking mechanism device reduces the internal stresses realized in the implant when secured by distributing the applied locking force over a broader length or area of the implant, thereby decreasing the possibility of implant failure post-operatively.  
         [0029]      FIG. 1  shows the general arrangement of a preferred embodiment of the in-series, dual locking mechanism device  10 . Generally, the in-series, dual locking mechanism device  10  includes a clamp  20 , a bone fastener  30 , a channel  21 , an implant  50 , and a locking mechanism  60 .  
         [0030]     With reference to  FIGS. 1-3 , the in-series, dual locking mechanism device  10  is comprised of a clamp  20  wherein a channel  21  is preferably defined by a floor member  22  and a pair of wall members  23 . The wall members  23  being preferably parallel relative to each other and project in an upward manner from the floor member  22 . The wall members  23  together with the floor member  22  form a U-shaped channel  21  approximately sized to receive an implant  50 . The internal sides of the wall members  23  may include internal threads  24  or alternatively an internal cam surface (Not Shown) to preferably engage a locking cap  40 . The wall members  23  preferably include at least two sets of internal threads  24  or internal cam surfaces (Not Shown) arranged in-line, substantially along the longitudinal axis of the channel  21 . As seen in  FIG. 1 , the two sets of internal threads  24  or alternatively internal cam surfaces (Not Shown) may be positioned in close proximity to each other, substantially along the longitudinal axis of the channel  21 . The orientation of the locking mechanism  60  described herein allows for the locking force to be applied over greater or broader area of the implant, thereby resulting in less actual stress to the implant. If the spacing of the locking force is too distant, the benefits of the in-series, dual locking mechanism will not be achieved. Typically as shown in  FIG. 2 , at least one through hole  25  is located in the floor member  22 . The hole  25  typically receives a bone fastener  30  prior to the insertion of an implant  50 . The longitudinal axis of the bone fastener  30  may be at a fixed angle relative to the floor member  22  following insertion into the hole  25  or be allowed to pivot within the hole  25 . The hole  25  may be counter bored, counter sunk, slotted, have a spherical seat, keyed or any combination or derivation of these manufacturing techniques, to allow the top portion of the bone fastener  30  to sit below the surface of the floor member  22 . The bone fastener  30  is typically configured as a bone screw (Not Shown) though, alternative bone fasteners may be utilized including, but not limited to bone fixation posts (Not Shown), bone staples (Not Shown), hooks (Not Shown), anchors (Not Shown), fixed head screws (Not Shown) and moveable head screws (Not Shown). It is understood to those skilled in the art that the bone fastener attachment structure described is for example only and that other configurations may be used, including a clamp  20  configured to be integrally coupled to a bone fastener  30 .  
         [0031]     As shown in  FIGS. 1 and 3 , the locking mechanism  60  is illustrated as including at least two externally threaded locking caps  40  threadably engaged with the internal threads  24  of the wall members  23 , although it is understood to those skilled in the art that other configurations are contemplated, including a locking cap configured to include an external cam surface (Not Shown) that engages with an internal cam surface (Not Shown) located within each wall member  23 . In the open position, the threaded locking caps  40  of the locking mechanism  60  initiate engagement with the internal threads  24  of the wall members  23  and allow the implant  50  to move freely within the channel  21 . When in the closed position, preferably the threaded locking caps  40  of the locking mechanism  60 , are substantially engaged with the internal threads  24  usually resulting in a pressing engagement or a compressive force being applied to the top surface  51  of the implant  50 . As shown in  FIG. 3 , the implant  50  is locked by at least two locking caps  40  preferably positioned adjacent and in-series to each other, substantially along the longitudinal axis of the channel  21 .  
         [0032]     Preferably, the implant  50  secured by the in-series, dual locking mechanism device  10  is shaped as an elongate and continuous rod. Alternative implants  50  may be secured by the in-series, dual locking mechanism device  10 , these include, but are not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. The implant  50  may be comprised of a material selected from the group consisting of stainless steel, carbon fiber composite, titanium, cobalt-chromium, shape memory metal, resorbable polymers, bio-inert metal, bio-inert polymeric materials, and combinations of these materials.  
         [0033]     Referring to  FIGS. 4-6 , an in-series, dual locking mechanism device  10  in accordance with another embodiment is shown and preferably includes a clamp  160  comprised of a cylinder  100  through which a channel  110  passes, a locking mechanism  140  which typically includes at least two locking caps  112 , an offset flange  130 , which may include at least one through hole  131  for receiving a bone fastener  250 .  
         [0034]     As seen in  FIG. 5 , the cylinder  100  includes an inner diameter  101  and an outer diameter  102 . The cylinder generally has a top, external surface  103  located on the outer diameter  102 . The inner diameter  101  is preferably configured and dimensioned to receive an implant  170 . Preferably, the implant  170  secured within the cylinder  100  is shaped as an elongate and continuous rod. Alternative implants  170  may be secured within the cylinder  100 , these include, but are not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. Further, the implant  170  may be comprised of a material selected from the group consisting of stainless steel, carbon fiber composite, titanium, cobalt-chromium, shape memory metal, resorbable polymers, bio-inert metal, bio-inert polymeric materials, and combinations of these materials.  
         [0035]     Referring to  FIGS. 4 and 5  the cylinder  100  may include at least two holes  120  which preferably pass from the top, external surface  103  through the outer diameter  102  and project into the inner diameter  101 . The centerline of the holes  120  may be about normal to the top, external surface  103 , though it is contemplated that the centerline of the holes  120  may be angled relative to the top external surface  103 . For all hole orientations, the location of the holes&#39;  120  exit points may be arranged in-series, substantially along the longitudinal axis of the cylinder  100 . The exit points of the holes  120  are also preferably positioned adjacent to each other, substantially along the longitudinal axis of the cylinder  100 .  
         [0036]     The locking mechanism  140  is illustrated in  FIG. 6  to include at least two externally threaded locking caps  112  whereby the locking caps  112  preferably engage the internal threads of the holes  120 , although other configurations are contemplated including a locking cap configured to include an external cam surface (Not Shown) that engages with an internal cam surface located within the holes  120 . In the open position, the locking caps  112  of the locking mechanism  140  are inserted and threadably engage the holes  120 , but do not project into the channel  110  thereby allowing the implant  170  to move freely within the channel  110  over the length of the cylinder  100 . The closed position of the locking mechanism  140  is typically achieved when the locking caps  112  protrude into the channel  110  and pressingly engage the implant  170 . The implant  170  is fixed by at least two locking caps  112  with preferably contact points that are adjacent and in-series to each other, substantially along the longitudinal axis of the cylinder  100 .  
         [0037]     As shown in  FIGS. 4-6 , the in-series, dual locking mechanism device  10  is preferably secured to a bone by a bone fastener  250  that passes through the offset flange  130 , though it is contemplated and understood by those skilled in the art that the bone fastener  250  may be integrally attached to the bottom surface  132 . The offset flange  130  is typically fixed at an almost perpendicular angle to the side of the cylinder  100 . At least one through hole  131  for receiving a bone fastener  250  is located within the offset flange  130 . Following insertion into the offset flange  130 , the longitudinal axis of the bone fastener  250  is oriented approximately normal thereto, or alternatively the bone fastener  250  may be allowed to pivot within the hole  131  allowing for angulation of the bone fastener  250 . The bone fastener  250  may be configured as a bone screw (Not Shown), but alternative configurations of bone fasteners may include, but are not limited to bone fixation posts (Not Shown), bone staples (Not Shown), hooks (Not Shown), anchors (Not Shown), fixed head screws (Not Shown) and moveable head screws (Not Shown). The embodiment of the bone fastener  250  as seen at  FIG. 13 , is a collared bone fastener  250  that includes two separate sets of threads. One portion of the collared bone fastener  250  is comprised of external threads  251  that are configured to self-thread into a bone. Attached at the end of the external threads  251  portion is a fixed collar  252 . A threaded post  253  portion is fixed to the opposite side of the fixed collar  252  relative to the external thread  251  portion. As seen in  FIG. 5 , the collared bone fastener  250  may be inserted into the offset flange  130  from the direction of the bottom surface  132 . Preferably, the collar  252  would make contact with bottom surface  132  with the threaded post  253  projecting above the top surface  133 . The in-series, dual locking mechanism device  10  being preferably secured to the collared bone fastener  250  with a locking nut  254 .  
         [0038]     It is understood to those skilled in the art that the bone fastener  30 ,  250  may be attached to embodiments described above in an alternative configuration. For example, the clamp  20  may be structured to include an offset flange  130  to which the bone fastener  30  attaches. Further, the cylinder  100  may be configured to allow for the bone fastener  30  to be attached to the bottom, external surface (Not Shown) of the cylinder  100  either in a rigid or modular fashion.  
         [0039]     Another embodiment of the in-series, dual locking mechanism device  10  shown in  FIGS. 7-11  requires the clamp to be preferably manufactured from a material that has a springy or resiliant/elastic-like material property, in that when loaded or deformed, the material will inherently try to regain its original shape. This further embodiment preferably includes a clamp  200  which is generally in the form of a bracket  201 . The clamp is preferably comprised of least one pair of loops  210  that create a channel  220  through which the implant  260  may pass. Each loop  210  typically has an attached pair of legs  211  whereby each pair of legs  211  preferably are joined together by a tab  230 . The tab  230  may include at least one through hole  233  for preferably receiving a collared bone fastener  250 .  
         [0040]     As seen in  FIG. 8 , the channel  220  for receiving the implant  260  is formed by at least one pair of loops  210 . Referring to  FIGS. 7 and 11 , the pair of loops  210  may be oriented along the longitudinal axis of the implant  260  in an in-series and preferably adjacent position. Preferably, the implant  260  secured within the channel  220  is shaped as an elongate and continuous rod. Alternative implants  260  may be secured within the channel  220 , these include, but are not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. Further, the implant  260  may be comprised of a material selected from the group consisting of stainless steel, carbon fiber composite, titanium, cobalt-chromium, shape memory metal, resorbable polymers, bio-inert metal, bio-inert polymeric materials, and combinations of these materials.  
         [0041]     The locking mechanism  240  is generally constructed to include at least one pair of loops  210 , the corresponding attached pair of legs  211 , a pair of tabs  230  that are comprised of an upper tab  231  and a lower tab  232  and at least one through hole  233  in each tab  230  and collared bone fastener  250  typically including a locking nut  254 . As shown in  FIG. 8 , from each loop  210  may extend a pair of legs  211 . The pair of legs  211  typically merge to form a tab  230 . The in-series, dual locking mechanism device  10  as seen in  FIG. 8  shows the two pairs of legs  211  forming an upper tab  231  and a lower tab  232 , although it is understood by one skilled in the art that other configurations may be used.  FIG. 9  shows the locking mechanism  240  in the open position, wherein the upper tab  231  and the lower tab  232  are almost parallel relative to each other with a gap between the tabs  230  opposing surfaces. In addition, the collared bone fastener  250  has been inserted through aligned holes  233  in the tabs  230  without the locking nut  254  being operated to its closed position. The open position allows the implant  260  to move freely within the channel  220 . The closed position for the locking mechanism  240  as shown in  FIG. 10  is typically achieved when the locking nut  254  threadably engages the threaded post  253  causing the upper tab  231  and the lower tab  232  to move in closer proximity resulting in the urging of the pair of loops  210  to pressingly engage the implant  260  in preferably adjacent and in-series locations, substantially along the longitudinal axis of the implant  260 .  
         [0042]     As shown in  FIGS. 8 and 11 , the in-series, dual locking mechanism device  10  is preferably secured to a bone by a collared bone fastener  250 . At least one through hole  233  for receiving a collared bone fastener  250  is located within the tabs  230 . Following the insertion into the tabs  230 , the longitudinal axis of the collared bone fastener  250  is oriented approximately normal thereto. As shown in  FIG. 13 , the collared bone fastener  250  is preferably configured to include three connected members, an externally threaded member  251  for insertion into a bone, a fixed collar member  252 , for seating onto the bottom surface of the lower tab  232  and a threaded post member  253  for preferably threadably engaging the locking nut  254 . As seen in  FIG. 7 , the collared bone fastener  250  may be inserted into the tabs  230  passing through the lower tab  232  with the threaded post  252  projecting above the upper tab  231 . The in-series, dual locking mechanism device  10  being preferably secured to the collared bone fastener  250  with a locking nut  254 .  
         [0043]     Though not shown, it is understood to those skilled in the art that the locking mechanism  240  of the alternative embodiment may be structured to include a locking cap  40  that is configured with an external cam surface, the locking cap  40  being inserted into the hole  233  to threadably engage an internal cam surface within the portion of the hole  233  located in the lower tab  232 . It is further understood that the bone fastener  30  for this alternative embodiment may be integrally coupled to the under surface of the lower tab  232 .  
         [0044]     Yet a further embodiment of the in-series, dual locking mechanism device  10  is seen in  FIGS. 14-17  that includes two channels  310 ,  311  that are substantially parallel to each other.  FIG. 15  shows the general arrangement of the alternative embodiment of the in-series, dual locking mechanism device  10  that includes a clamp  300 , a bone fastener  320 , at least two channels  310 ,  311 , at least two implants  330 ,  331  and a locking mechanism  340 . With reference to  FIGS. 14 and 15 , the in-series, dual locking mechanism device  10  is comprised of a clamp  300  wherein the channels  310 ,  311  are preferably defined by a floor member  312  and three wall members  313 ,  314 . The wall members  313 ,  314  being preferably parallel relative to each other with the side wall members  313  and middle wall member  314  being separated by a distance about equal to the width of the floor member  312  respectively. The three wall members  313 ,  314  project in an upward manner from the floor member  312  to form two U-shaped channels  310 ,  311  with both being approximately sized to receive an implant  330 ,  331 . The internal sides of the side wall members  313  and both sides of the middle wall member  314  may include internal threads  315  or alternatively internal cam surfaces (Not Shown) preferably to engage a locking cap  350 . The wall members  313 ,  314  preferably include at least two sets of internal threads  315  or alternatively internal cam surfaces. (Not Shown) arranged in-series along the longitudinal axis of the channels  310 ,  311 . As seen in  FIG. 14 , the two sets of internal threads  315  may be positioned in close proximity or adjacent to each other along the longitudinal axis of their respective channels  310 ,  311 . Typically, as shown in  FIG. 14 , at least one through hole  360  is located through the middle wall member  314 . The hole  360  may receive a bone fastener  320  prior to the insertion of the implants  330 ,  331 . The longitudinal axis of the bone fastener  320  may be at a fixed angle relative to the floor member  312  following insertion into the hole  360  or alternatively, may be allowed to pivot within the hole  360 . The hole  360  may be counter bored, counter sunk, slotted, keyed, have a spherical seat or any combination or derivation of these manufacturing techniques, to allow the top portion of the bone fastener  320  to sit within the middle wall member  314 . The bone fastener  320  is typically configured as a bone screw (Not Shown), but alternative bone fasteners may be utilized including, but not limited to bone fixation posts (Not Shown), bone staples (Not Shown), hooks (Not Shown), anchors (Not Shown), fixed head screws (Not Shown) and moveable head screws (Not Shown. It is understood to those skilled in the art that the method of attaching the bone fastener  320  to the clamp  300  described herein is for example and that other configurations may be used, including having the bone fastener  320  integrally coupled to the bottom surface of the clamp  300 .  
         [0045]     As shown in  FIGS. 15, 16 ,  17 , the locking mechanism  340  is illustrated as including at least four externally threaded locking caps  350  threadably engaged with the internal threads  315  of the wall members  313 ,  314 , although it is understood by those skilled in the art that other configurations are contemplated, including a locking cap configured to include an external cam surface (Not Shown) that engages with an internal cam surface (Not Shown) located within each wall member  313 ,  314 . In the open position, the threaded locking caps  350  of the locking mechanism  340  initiate engagement with the internal threads  315  of the wall members  313 ,  314  and allow the implants  330 ,  331  to move freely within the channels  310 ,  311 . When in the closed position, preferably the threaded locking caps  350  of the locking mechanism  340 , are substantially engaged with the internal threads  315  usually resulting in a pressing engagement or compressive force being applied to the top surface  332  of the implants  330 ,  331 . As shown in  FIGS. 15, 16  and  17 , each implant  330 ,  331  is locked by at least two locking caps  350  preferably positioned adjacent and in-series to each other, substantially along the longitudinal axis of their respective channels  310 ,  311 . The importance of the configuration of the locking mechanism  340  is discussed above herein.  
         [0046]     Preferably, the implants  330 ,  331  secured within the channels  310 ,  311  by the in-series, dual locking mechanism device  10  are shaped as elongate and continuous rods. Alternative implants  330 ,  331  may be secured by the in-series, dual locking mechanism device  10 , these include, but are not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. The implants  330 ,  331  may be comprised of a material selected from the group consisting of stainless steel, carbon fiber composite, titanium, cobalt-chromium, shape memory metal, resorbable polymers, bio-inert metal, bio-inert polymeric materials, and combinations of these materials.  
         [0047]     As shown in  FIGS. 16 and 17 , the implants  330 ,  331  may be locked in the channels  310 ,  311  in various construct arrangements, including, but not limited in parallel or in multi-level segmentations. Such arrangements will depend on the structural application that the implants  330 ,  331  are being utilized to address  
         [0048]     The steps of the method to use the in-series, dual locking mechanism device  10  include exposing the bone on which the clamp  20  is to be attached. Depending on the type of bone, a preferred bone fastener  30  is selected from a kit. The next step of the method is to preferably attached the bone fastener  30  to the clamp  20 . The next step is to typically drill a pilot hole into at least one bone. The following step is preferably to insert the bone fastener  30  into the pilot hole, fixing the clamp  20  in close approximation to the bone. Following securement of the clamp  20 , the last step would be to place the implant  50  within the channel  21 . Preferably, the implant  50  is configured as at least one elongate and continuous rod though, alternative implants are contemplated for use in the in-series, dual locking mechanism device  10 . These alternative implants include, but are not limited to plates, bars, tethers, cables, elastic structures and dynamic stabilization members. Following the implant placement step, typically the implant  50  is locked within the channel  21  by closing the locking mechanism  60  and thereby pressingly engaging the implant  50  in at least two adjacent and in-series locations along the top surface of the implant  50 . It is contemplated that depending upon the embodiment used to lock the implant  50  in place, the locking mechanism  140 ,  240  may be comprised of at least two locking caps  112  or at least two loops  210 , respectively.  
         [0049]     Although the preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions and substitutions can be made without departing from its essence and therefore these are to be considered to be within the scope of the following claims.