Patent Publication Number: US-2023157729-A1

Title: Hinge-Link Spinal Correction Device and Method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part patent application of U.S. Ser. No. 16/820,097 filed on Mar. 16, 2020, which is a non-provisional patent application of and claims priority to U.S. provisional patent application Ser. No. 62/822,345 filed on Mar. 22, 2019 and entitled “Hinge-Link Spinal Correction Device and Method,” the contents of which are hereby incorporated by reference in their entirety. 
     STATEMENT OF FEDERALLY FUNDED RESEARCH 
     Not applicable. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates in general to the treatment of spinal deformations. In particular, the present invention relates to the correction of spinal deformation in which a vertebral column resection is performed. 
     BACKGROUND OF THE INVENTION 
     Without limiting the scope of the invention, its background is described in connection with the use of a device to stabilize and manipulate a deformed spine on which a vertebral column resection (VCR) or spinal correction is being or has been performed into a desired position and then fixing the spine in that configuration. In some cases of severe spinal deformity, it is advisable to remove one or more vertebrae to allow manipulation of the spine into a more normal curve, sometimes in stages over a period of time. The spine must be stabilized for performance of the VCR; manipulated into the more normal configuration; held in place over a period of time until the spine adapts to that configuration, and sometimes stabilized and manipulated repeatedly during subsequent spinal corrections and then held in place until the spine adapts to each new configuration. Prior art method and systems are difficult and risky because they do not provide for fine control of the initial stabilization during the VCR, stabilization, manipulation, or the long-term fixing in place of the spine without risk of compression, distraction, or translation of the spinal cord. 
     U.S. Pat. No. 9,433,433, to Montello, et al., is said to disclose a posterior vertebral plating system comprising a plate and a plurality of attachment members. The plate is said to have a plurality of holes extending through the plate from an upper surface to a lower surface, and the plate is configured to extend along the posterior side of at least two vertebrae adjacent at least one boney structure of each of the vertebrae. The holes are said to be spaced in such a way that a first plurality of holes is positionable over a boney structure of a first vertebra to define a plurality of fixation points to the first vertebra and a second plurality of holes is positionable over boney structure of a second vertebra to define a plurality of fixation points to the second vertebra. The attachment members are said to be insertable through the holes of the plate and into the boney structure of a corresponding vertebra to fix the plate to the vertebra. 
     U.S. Pat. No. 10,004,538, to McNab et al., is said to disclose a surgical instrument that includes a first arm engageable with a first spinal construct disposed with a first vertebral surface. A second arm is said to be connected with the first arm via a pivot and to be engageable with a second spinal construct disposed with a second vertebral surface. The first arm is said to be movable to rotate the first spinal construct relative to the pivot and/or the second arm is said to be movable to rotate the second spinal construct relative to the pivot such that the first vertebral surface is moved relative to the second vertebral surface. 
     U.S. Pat. No. 9,579,126, to Zhang, et al., and U.S. Pat. No. 10,105,166, to Zhang, et al., are said to disclose a rod link reducer of a spinal fixation system that includes a first and a second spinal rod manipulator; a first spinal rod manipulator joint connected to the first spinal rod manipulator and a second spinal rod manipulator joint connected to the second spinal rod manipulator; a first and a second translatable transverse shaft connected to the first and second joints, respectively; and a universal reducer connected to both the first and second translatable transverse shafts, wherein the universal reducer, the shafts and the linkers provide movement and temporary fixation of a spine that has been manipulated into a final position during spinal surgery. 
     Methods and systems for stabilization, manipulation, and fixation of a deformed spine subject to a VCR are ineffective and risky. Effective methods and systems that reduce risk for stabilization, manipulation, and fixation of a deformed spine subject to a VCR to prevent compression, distraction, or translation of the spinal cord are desirable. 
     SUMMARY OF THE INVENTION 
     In some embodiments of the disclosure, a device for spinal correction is disclosed as including a stabilizer assembly including: a hinge including: a first rod-bearing leaf; a second rod-bearing leaf rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the stabilizer assembly; a locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at a desired angle; a first stabilizing rod coupled to the first rod-bearing leaf; a second stabilizing rod coupled to the second rod-bearing leaf; and a plurality of monoaxial or polyaxial links, wherein each monoaxial or polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod and is movably couplable to a first spinal rod fixed to a spine or to a second spinal rod fixed to the spine; wherein the stabilizer assembly is couplable to the first spinal rod or to the second spinal rod to stabilize the spine to prevent compression, distraction, or translation of the spinal cord during a spinal correction. In one aspect, the locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at the desired angle includes one or more screws. In another aspect, the first stabilizing rod is coupled to the first rod-bearing leaf with a first threaded portion of the first stabilizing rod. In another aspect, the second stabilizing rod is coupled to the second rod-bearing leaf with a second threaded portion of the second stabilizing rod. In another aspect, each monoaxial or polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod with one or more adjustment nuts or one or more locking pins. In another aspect, each polyaxial link is lockable at a position on the first stabilizing rod or the second stabilizing rod and is lockable at an angle to the first stabilizing rod or the second stabilizing rod with two or more adjustment nuts. In another aspect, each monoaxial or polyaxial link is movably couplable to the first spinal rod or to the second spinal rod at one or more components, each comprising a recess shaped to receive the first spinal rod or to the second spinal rod, and lockable in position with one or more screws. In another aspect, the first stabilizing rod is rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the first stabilizing rod or the second stabilizing rod is rotatably coupled to the second rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the second stabilizing rod; and the first stabilizing rod has a locking mechanism to lock it at a desired position or the second stabilizing rod has a locking mechanism to lock it at a desired position. In another aspect, the first stabilizing rod or the second stabilizing rod is threaded and adjustment nuts are mounted on the first stabilizing rod or the second stabilizing rod to provide longitudinal freedom of movement or locking of one or more of the plurality of monoaxial or polyaxial links on the first stabilizing rod or the second stabilizing rod. 
     In some embodiments of the disclosure, a kit is disclosed as including a stabilizer assembly including: a hinge including: a first rod-bearing leaf; a second rod-bearing leaf rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the stabilizer assembly; a locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at a desired angle; a first stabilizing rod coupled to the first rod-bearing leaf; a second stabilizing rod coupled to the second rod-bearing leaf; and a plurality of monoaxial or polyaxial links, wherein each monoaxial or polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod and is movably couplable to a first spinal rod fixed to a spine or to a second spinal rod fixed to the spine; wherein the stabilizer assembly is couplable to the first spinal rod or to the second spinal rod to stabilize the spine to prevent compression, distraction, or translation of the spinal cord during a spinal correction. In one aspect, the first stabilizing rod is rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the first stabilizing rod or the second stabilizing rod is rotatably coupled to the second rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the second stabilizing rod; and the first stabilizing rod has a locking mechanism to lock it at a desired position or the second stabilizing rod has a locking mechanism to lock it at a desired position. In another aspect, the first stabilizing rod or the second stabilizing rod is threaded and adjustment nuts are mounted on the first stabilizing rod or the second stabilizing rod to provide longitudinal freedom of movement or locking of one or more of the plurality of monoaxial or polyaxial links on the first stabilizing rod or the second stabilizing rod. 
     In some embodiments of the disclosure, a method of stabilizing a spine is disclosed as including providing a patient in need of stabilization of a spine, wherein a plurality of spinal rods have been fixed to the spine; coupling a stabilizer assembly of a device for spinal correction to at least one of the plurality of spinal rods, wherein the stabilizer assembly includes: a hinge including: a first rod-bearing leaf; a second rod-bearing leaf rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the stabilizer assembly; and a locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at a desired angle; a first stabilizing rod coupled to the first rod-bearing leaf; a second stabilizing rod coupled to the second rod-bearing leaf; and a plurality of monoaxial or polyaxial links, wherein each monoaxial or polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod and is movably coupled to a first spinal rod fixed to a spine or to a second spinal rod fixed to the spine; and stabilizing the spine at a desired spinal configuration; wherein the stabilizer assembly is couplable to the first spinal rod or to the second spinal rod to stabilize the spine to prevent compression, distraction, or translation of the spinal cord during a spinal correction. In one aspect, the locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at the desired angle includes one or more screws. In another aspect, the first stabilizing rod is coupled to the first rod-bearing leaf with a first threaded portion of the first stabilizing rod. In another aspect, the second stabilizing rod is coupled to the second rod-bearing leaf with a second threaded portion of the second stabilizing rod. In another aspect, each monoaxial or polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod with one or more adjustment nuts or one or more locking pins. In another aspect, each polyaxial link is lockable at a position on the first stabilizing rod or the second stabilizing rod and is lockable at an angle to the first stabilizing rod or the second stabilizing rod with two or more adjustment nuts. In another aspect, each monoaxial or polyaxial link is movably couplable to the first spinal rod or to the second spinal rod at one or more components, each comprising a recess shaped to receive the first spinal rod or to the second spinal rod, and lockable in position with one or more screws. In another aspect, the first stabilizing rod is rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the first stabilizing rod or the second stabilizing rod is rotatably coupled to the second rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the second stabilizing rod; and the first stabilizing rod has a locking mechanism to lock it at a desired position or the second stabilizing rod has a locking mechanism to lock it at a desired position. In another aspect, the first stabilizing rod or the second stabilizing rod is threaded and adjustment nuts are mounted on the first stabilizing rod or the second stabilizing rod to provide longitudinal freedom of movement or locking of one or more of the plurality of monoaxial or polyaxial links on the first stabilizing rod or the second stabilizing rod. In another aspect, the first stabilizing rod or the second stabilizing rod is threaded and adjustment nuts are mounted on the first stabilizing rod or the second stabilizing rod to provide longitudinal freedom of movement or locking of one or more of the plurality of monoaxial or polyaxial links on the first stabilizing rod or the second stabilizing rod. In another aspect, the method further includes coupling the stabilizer assembly to at least one of the plurality of spinal rods oriented to allow the hinge to have coronal freedom of movement, sagittal freedom of movement, or a combination of coronal and sagittal freedom of movement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures, in which: 
         FIGS.  1 A,  1 B, and  1 C  show a stabilizer assembly. 
         FIG.  2 A  shows another stabilizer assembly. 
         FIGS.  2 B,  2 C, and  2 D  illustrate top views of the stabilizer assembly of  FIG.  2 A . 
         FIGS.  2 E,  2 F, and  2 G  illustrate perspective views of the stabilizer assembly of  FIG.  2 A . 
         FIG.  2 H  depicts a view of the stabilizer assembly of  FIG.  2 A  with a wrench to adjust adjustment nuts. 
         FIG.  2 I  shows a lateral view of the stabilizer assembly of  FIG.  2 A . 
         FIG.  3 A  shows a monoaxial link. 
         FIG.  3 B  shows another monoaxial link. 
         FIG.  3 C  shows still another monoaxial link. 
         FIG.  3 D  shows a cross-section of a polyaxial link. 
         FIGS.  3 E,  3 F,  3 G, and  3 H  show perspective views of the polyaxial link of  FIG.  3 D . 
         FIG.  3 I  shows a perspective view of another polyaxial link. 
         FIG.  3 J  shows a perspective view of still another polyaxial link. 
         FIGS.  4 A,  4 B, and  4 C  illustrate the stabilizer assembly of  FIGS.  1 A,  1 B, and  1 C  coupled to spinal rods, with the spinal rods attached to a simulated spine. 
         FIGS.  5 A and  5 B  depicts the stabilizer assembly of  FIGS.  1 A,  1 B, and  1 C  being used with a manipulator assembly. 
         FIGS.  6 A,  6 B, and  6 C  show a coronal plane control correction, a sagittal plane control correction, and a longitudinal correction using the stabilizer assembly of  FIG.  2 A , respectively. 
         FIGS.  6 D and  6 E  show two different sagittal plane control corrections using the stabilizer assembly of  FIG.  2 A , and  FIG.  6 F  illustrates a top view of the sagittal plane control correction of  FIG.  6 E . 
         FIGS.  6 G,  6 H,  6 I, and  6 J  show various views of stabilizer assembly of  FIG.  2 I . 
         FIG.  7 A  shows a coronal plane control correction using the stabilizer assembly of  FIG.  2 I . 
         FIG.  7 B  shows a sagittal plane control correction using the stabilizer assembly of  FIG.  2 I . 
         FIG.  7 C  shows a longitudinal correction using the stabilizer assembly of  FIG.  2 I . 
         FIG.  7 D  shows the stabilizer assembly of  FIG.  2 I  with the hinge positioned at the apex of a spinal deformity, at which a VCR has been performed. 
         FIGS.  7 E and  7 F  show how the hinge of the stabilizer assembly of  FIG.  2 I  and the manipulator assembly of  FIGS.  5 A and  5 B  are used together to perform a spinal correction. 
         FIG.  7 G  shows how the hinge of the stabilizer assembly of  FIG.  2 I  is used to stabilize the spinal correction of  FIGS.  7 E and  7 F . 
         FIG.  8    depicts a flowchart of a method embodiment of the present invention. 
         FIG.  9 A  shows a manipulator rod and a manipulator clamp with the stabilizer assembly. 
         FIG.  9 B  shows q manipulator rod in position to be coupled to the hinge of the stabilizer assembly. 
         FIG.  9 C  shows a side view of the manipulator clamp coupled to a stabilizing rod and a spinal rod. 
         FIG.  9 D  shows the distal end of a manipulator clamp coupled to a stabilizing rod and a spinal rod. 
         FIG.  9 E  shows the rod-bearing leaves of the stabilizer assembly. 
         FIG.  9 F  shows the rod-bearing leaves of the stabilizer assembly coupled at the hinge. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Illustrative embodiments of the system of the present application are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer&#39;s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction. 
       FIGS.  1 A and  1 B  show an embodiment of the present invention which prevents compression, distraction, or translation of the spinal cord during a vertebral resection surgery, the stabilizer assembly  100 .  FIG.  1 A  shows a side view and  FIG.  1 B  shows a top view. The stabilizer assembly  100  includes the hinge  105 , which includes rod-bearing leaves  110  and  115  and hinge locking mechanism  120 . The rod-bearing leaf  115  is rotatably coupled to the rod-bearing leaf  110  to allow coronal or sagittal freedom of movement, or both, depending on the orientation of the stabilizer assembly relative to the spine. Hinge locking mechanism  120  is used to lock the rod-bearing leaves  110  and  115  at a desired angle. Stabilizing rods  125  and  130  are coupled to the rod-bearing leaves  110  and  115 , via, e.g., threaded portions of the stabilizing rods  125  and  130  nearest the hinge  105 . The stabilizing rod  125 , the stabilizing rod  130 , or both are threaded and adjustment nuts are mounted on the stabilizing rod  125 , the stabilizing rod  130 , or both to provide longitudinal freedom of movement. 
       FIG.  1 C  shows the stabilizer assembly  100  of the present invention coupled to the spinal rods  135  and  140 , which may be straight or curved.  FIG.  1 C  shows the hinge  105  with the rod-bearing leaves  110  and  115 , the locking mechanism  120 , the stabilizing rods  125  and  130 , and four links  145   a ,  145   b ,  145   c , and  145   d . The links  145   a ,  145   b ,  145   c , and  145   d  are coupled to the spinal rods  135  and  140 . The links  145   a ,  145   b ,  145   c , and  145   d  represent a number of embodiments of links of the present invention, including monoaxial and polyaxial links described herein. 
       FIG.  2 A  depicts another embodiment of the present invention which prevents compression, distraction, or translation of the spinal cord during a vertebral resection surgery, the stabilizer assembly  200 . The stabilizer assembly includes the hinge  205 , which is configured to allow coronal or sagittal freedom of movement, or both, of the stabilizer assembly, depending on the orientation of the stabilizer assembly relative to the spine. Rod-bearing leaves  210  and  215  are rotatably coupled to allow coronal or sagittal freedom of movement, or both, depending on the orientation of the stabilizer assembly relative to the spine. Hinge locking mechanism  220  is used to lock the rod-bearing leaves  210  and  215  at a desired angle. Stabilizing rods  225  and  230 , which are threaded on at least a portion of their respective lengths, are coupled to the rod-bearing leaves  210  and  215 , via, e.g., threaded portions at the ends of the stabilizing rods  225  and  230  nearest the hinge  205 . The stabilizing rods  225  and  230  are rotatably coupled to the rod-bearing leaves  210  and  215  such that they have freedom of movement with axes of rotation that are at right angles to a plane formed when the rod-bearing leaves  210  and  215  form a 180-degree angle. Locking mechanisms  232  and  234  are used to lock the stabilizing rods  225  and  230 , respectively, at desired positions. The stabilizing rods  225  and  230  are threaded and carry exemplary adjustment nuts  235   a ,  235   b ,  235   c , and  235   d  to move links (not shown) longitudinally on the stabilizing rods  225  and  230 , allowing longitudinal freedom of movement along the stabilizing rods  225  and  230 . The adjustment nuts  235   a ,  235   b ,  235   c , and  235   d  can be used to lock links in place on the stabilizing rods  225  and  230 . 
       FIG.  2 B  shows a top view of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set at a 180-degree angle.  FIGS.  2 C and  2 D  depict top views of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set at different angles to provide examples of the coronal freedom of motion allowed by the hinge  205 . 
       FIG.  2 E  shows a lateral view of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set at a 180-degree angle and the stabilizing rods  225  and  230  aligned with each other.  FIGS.  2 F and  2 G  depict lateral views of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set a 180-degree angle and the stabilizing rods  225  and  230  set at different angles to provide examples of the sagittal freedom of motion of the stabilizing rods  225  and  230 . 
       FIG.  2 H  shows a lateral view of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set at a 180-degree angle and the stabilizing rods  225  and  230  aligned with each other, with a wrench  240  positioned to adjust an adjustment nut  235  to move it longitudinally on the stabilizing rod  230  to position a link (not shown) on the stabilizing rod  230 . 
       FIG.  2 I  shows a lateral view of the stabilizer assembly  200  with the rod-bearing leaves  210  and  215  of the hinge  205  set at a 180-degree angle and the stabilizing rods  225  and  230  aligned with each other, with eight exemplary adjustment nuts  235   a ,  235   b ,  235   c ,  235   d ,  235   e ,  235   f ,  235   g , and  235   h , four on each of the stabilizing rods  225  and  230 . The adjustment nuts can be made from any material such as metal, polymers, composites, etc. 
       FIG.  3 A  shows a monoaxial link  300  of the present invention.  FIG.  3 A  illustrates a monoaxial link  300  of the present invention. A plurality of links  300  may be movably coupled to one or both of the stabilizing rods  125  and  130  (not shown), at the upper end  302  of each link  300 . Each link  300  can be positioned as desired on a stabilizing rod  125  or  130  using, e.g, a set-screw  304 , to lock it into position. Each link  300  is movably couplable to a spinal rod (not shown) that is fixed to a spine using, e.g., bone screws, at the lower end  306  of each link  300 . Each link  300  can be positioned as desired on spinal rod using, e.g, a set-screw  308 , to lock it into position. 
       FIG.  3 B  illustrates another monoaxial link  310  of the present invention. A plurality of links  310  may be movably coupled to one or both of the stabilizing rods  125  and  130  (not shown), at the upper end  312  of each link  310 . Each link  310  can be positioned as desired on a stabilizing rod  125  or  130  using, e.g, a set-screw  314 , to lock it into position. Each link  310  is movably couplable to a spinal rod (not shown) that is fixed to a spine using, e.g., bone screws, at the lower end  316  of each link  310 . Each link  310  can be positioned as desired on spinal rod using, e.g, a set-screw  318 , to lock it into position. 
       FIG.  3 C  illustrates still another monoaxial link  320  of the present invention. A plurality of links  320  may be movably coupled to one or both of the stabilizing rods  125  and  130  (not shown), at the upper end  322  of each link  320 . Each link  320  can be positioned as desired on a stabilizing rod  125  or  130  using, e.g, a locking pin (not shown) set in place through holes  324 , to retain the link  320  on the stabilizing rod  125  or  130  (not shown). Each link  320  is movably couplable to a spinal rod (not shown) that is fixed to a spine using, e.g., bone screws, at the lower end  326  of each link  320 . Each link  320  can be positioned as desired on spinal rod using, e.g, a set-screw  328 , to lock it into position. 
       FIG.  3 D  shows a cross-section, and  FIGS.  3 E,  3 F,  3 G, and  3 H  show perspective views of a polyaxial link  340  of the present invention, with each figure showing one or more features of the polyaxial link  340  in various configurations. Each of a plurality of polyaxial links  340  is movably coupled to one of the stabilizing rods  125  and  130  (of which stabilizing rod  125  is shown and stabilizing rod  130  is not shown), at the upper portion  342  of each polyaxial link  340 . Each polyaxial link  340  can be positioned as desired on a stabilizing rod  125  or  130  ( 130  not shown) using e.g., a pair of adjustment nuts  344   a  and  344   b , shaped to match the shape of the upper portion  342 , to lock it into position. These adjustment nuts  344   a  and  344   b , and similar ones elsewhere on the threaded stabilizing rod  125  or  130  ( 130  not shown), can be locked and unlocked multiple times without damaging the adjustment nut threads or the stabilizing rod threads. The upper portion  342  of polyaxial link  340  is spherically shaped with a recess  346  shaped to receive a stabilizing rod  125  or  130  ( 130  not shown). The recess  346  is wider than the stabilizing rod  125  or  130  ( 130  not shown), and the bottom of the recess  346  includes two ramped portions  348   a  and  348   b  meeting at an apex  350 . When the polyaxial link  340  is positioned on a stabilizing rod  125  or  130  ( 130  not shown), the stabilizing rod  125  or  130  ( 130  not shown) contacts at least the apex  350 , which keeps the stabilizing rod  125  or  130  ( 130  not shown) centered in the recess  346 , while the width of the recess  346  and the ramps  348   a  and  348   b  permit the polyaxial link  340  to be set at an angle to an axis of the stabilizing rod  125  or  130  ( 130  not shown) up a limit of, e.g., 10, 15, 20, 25, 30, 35, 40, 45, or more degrees, in any direction. When the stabilizing rod  125  or  130  ( 130  not shown) is at the desired angle in the recess  346  and the polyaxial link  340  is at the desired position on the stabilizing rod  125  or  130  ( 130  not shown), the adjustment nuts  344   a  and  344   b  can be used to lock the polyaxial link  340  in place. A locking pin  352  may also be used to further secure the stabilizing rod  125  or  130  ( 130  not shown) in place. The lower portion  354  of the polyaxial link  340  has a recess  356  shaped to receive a spinal rod  146 , which is attached to the patient&#39;s spine (not shown). Each polyaxial link  340  can be positioned at a desired location on the spinal rod  146  and locked into place using, e.g, a set screw  358 . 
       FIG.  3 E  illustrates the polyaxial link  340  with the adjustment nuts  344   a ,  344   b  disengaged.  FIG.  3 F  shows the polyaxial link  340  from the top, with adjustment nuts  344   a  and  344   b  engaged, and locked into a position at an angle to the stabilizing rod  125 .  FIG.  3 G  illustrates the polyaxial link  340  with the adjustment nut  344   a  engaged and adjustment nut  344   b  disengaged and a locking pin  352  in place.  FIG.  3 H  illustrates the polyaxial link  340  with the adjustment nuts  344   a ,  344   b  engaged. 
       FIG.  3 I  shows a perspective view of the polyaxial link  340 , showing the upper section  342 , the recess  346 , the lower portion  354 , and the recess  356 . 
       FIG.  3 J  shows a perspective view of the polyaxial link  360 . The polyaxial link  360  is similar to the polyaxial link  340  except that the bottom end  374  of the polyaxial link  360  has two components or prongs,  374   a  and  374   b . The prongs  374   a  and  374   b  have recesses  376   a  and  376   b , respectively, shaped to receive spinal rod  146  (not shown), permitting engagement with a spinal rod  146  at two places. The polyaxial link  360  can be locked into place on spinal rod  146  using screws  378   a  and  378   b . Engagement of the polyaxial link  360  with spinal rod  146  at two places provides increased stability of the polyaxial link  360  when engaged, compared to single-component or -prong polyaxial links such as the polyaxial link  340 . Among other features of the polyaxial link  360 ,  FIG.  3 J  shows the upper portion  362  of the polyaxial link  360 , with a recess  366  shaped to receive stabilizing rod  125  or  130  (neither are shown). The components or prong similar to prongs  374   a  and  374   b  may also be used on the monoaxial links disclosed herein. 
       FIGS.  4 A,  4 B, and  4 C  illustrate the stabilizer assembly  100  of the present invention coupled to the spinal rods  135  and  140 , with the spinal rods  135  and  140  attached to a simulated spine  400 .  FIGS.  4 A and  4 B  illustrate the hinge  105  positioned at the apex of the spinal deformity, at which a VCR has been performed.  FIG.  4 C  illustrate the hinge  105  positioned at the apex of the spinal deformity, at which the deformity has been corrected. 
       FIGS.  5 A and  5 B  depict the stabilizer assembly  100  being used in conjunction with a manipulator assembly  500 .  FIGS.  5 A and  5 B  illustrate how the stabilizer assembly  100  and the manipulator assembly  500  are used together to perform a spinal correction. Manipulator assembly  500  includes the handles  505  and  510  and the connecting rod  515 . The connecting rod  515  is movably coupled by, e.g., one or more clamps or one or more screws, to the handles  505  and  510  to stabilize or fix the handles  505  and  510  relative to one another as desired. The handles  505  and  510  are couplable to spinal rods  135  and  140  to permit manipulation of the spine into a fixed configuration for the stabilizer assembly to maintain.  FIGS.  5 A and  5 B  show the manipulator assembly  500  coupled to two spinal rods  135  and  140 , with the handles  505  and  510  in different relative positions and with the simulated spine  400  manipulated to two different desired configurations. The stabilizer assembly  100  is also shown. 
       FIG.  6 A  depicts a coronal plane control correction using the stabilizer assembly  200 . The rod-bearing leaves  210  and  215  are set at a desired angle to position the simulated spine  400  as desired.  FIG.  6 B  depicts a sagittal plane control correction using the stabilizer assembly  200 . The stabilizing rods  225  and  230  are set at desired positions to position the simulated spine  400  as desired.  FIG.  6 C  depicts a longitudinal correction using the stabilizer assembly  200 . The links  145   a ,  145   b ,  145   c , and  145   d  are set at desired positions by the adjustment nuts  635   a ,  635   b ,  635   c ,  635   d ,  635   e , and  635   f.    
       FIG.  6 D  depicts a sagittal plane control correction using the stabilizer assembly  200 . The stabilizing rods  225  and  230  are set at desired positions to position the simulated spine  400  as desired.  FIG.  6 E  depicts a sagittal plane control correction using the stabilizer assembly  200 . The stabilizer assembly  200  is rotated 90 degrees from the position shown in  FIG.  6 D  to allow the hinge  205  to have sagittal freedom of motion. The rod-bearing leaves  210  and  215  of the hinge  205  are set at a desired angle to position the simulated spine  400  as desired.  FIG.  6 F  depicts a top view of the sagittal plane control correction of  FIG.  6 E . 
       FIGS.  6 G,  6 H,  6 I, and  6 J  show various views of stabilizer assembly  200  with adjustment nuts  344   a ,  344   b ,  344   c , and  344   d  (where adjustment nuts  344   c  and  344   d  are similar to adjustment nuts  344   a  and  344   b ); retaining pins  352   a ,  352   b ,  352   c , and  352   d ; polyaxial links  360   a  and  360   b ; and monoaxial links  320   a  and  320   b  mounted on stabilizing arms  225  and  230 , with simulated spine  600 .  FIG.  6 G  indicates all of these items and illustrates the hinge  200  positioned at the apex of the spinal deformity, at which a VCR has been performed.  FIG.  6 H  illustrates the hinge  200  positioned at the apex of the spinal deformity, at which the deformity has been corrected.  FIG.  6 I  indicates another view (concave side view) of  FIG.  6 G . FIG. J indicates another view (concave side view) of  FIG.  6 H . 
     In  FIGS.  6 G,  6 H,  6 I, and  6 J , adjustment nuts  344   a ,  344   b ,  344   c , and  344   d ; polyaxial links  360   a  and  360   b ; and monoaxial links  320   a  and  320   b  include metal coated with Teflon®. All monoaxial links, polyaxial links, and adjustment nuts discussed herein may include metal, Teflon®, some combination, e.g., Teflon®-coated metal, polymers, composites, etc. 
       FIGS.  7 A- 7 G  illustrate various uses of the stabilizer assembly  200  of  FIG.  2 I .  FIG.  7 A  shows a coronal plane control correction using the stabilizer assembly  200 .  FIG.  7 B  shows a sagittal plane control correction using the stabilizer assembly  200 .  FIG.  7 C  depicts a longitudinal correction using the stabilizer assembly  200 .  FIG.  7 D  shows the stabilizer assembly  200  with the hinge  205  positioned at the apex of a spinal deformity, at which a VCR has been performed.  FIGS.  7 E and  7 F  illustrate how the hinge of the stabilizer assembly  200  and the manipulator assembly  500  of  FIGS.  5 A and  5 B  are used together to perform a spinal correction.  FIG.  7 G  depicts how the hinge  205  of the stabilizer assembly  200  is used to stabilize the spinal correction of  FIGS.  7 E and  7 F . 
     Embodiments of the present invention can be used in conjunction with existing instruments, tools, and other devices generally used in treating spinal conditions. 
     Components of the present invention, including the stabilizer assembly and the polyaxial links, may be made of a non-organic material that is durable and that can be implanted in a human body, such as titanium, stainless steel, spring steel, aluminum, niobium, carbon fiber, ceramics, polymers, composites or any relatively hard material (e.g. Titanium-Aluminium-Niobium-alloy). Generally, the material selected will be biocompatible, that is, compatible with the surrounding bone and tissue. 
       FIG.  8    depicts a flowchart of a method embodiment of the present invention. Method  800  of stabilizing a spine includes block  805 , providing a patient in need of stabilization of a spine, wherein a plurality of spinal rods have been fixed to the spine. Block  810  includes coupling a stabilizer assembly of a device for spinal correction to at least one of the plurality of spinal rods, wherein the stabilizer assembly includes a hinge including a first rod-bearing leaf; a second rod-bearing leaf rotatably coupled to the first rod-bearing leaf to provide coronal or sagittal freedom of movement, or both, of the stabilizer assembly; and a locking mechanism to lock the first rod-bearing leaf and the second rod-bearing leaf at a desired angle; a first stabilizing rod coupled to the first rod-bearing leaf and a second stabilizing rod coupled to the second rod-bearing leaf, wherein the first stabilizing rod, the second stabilizing rod, or both, are threaded and adjustment nuts are mounted on the first stabilizing rod, the second stabilizing rod, or both, to provide longitudinal freedom of movement; and a plurality of polyaxial links, wherein each polyaxial link is movably coupled to the first stabilizing rod or to the second stabilizing rod and is movably coupled to a first spinal rod fixed to a spine or to a second spinal rod fixed to the spine. Included in block  815  is fixing the spine at a desired spinal configuration. In block  820 , the stabilizer assembly is couplable to the first spinal rod or to the second spinal rod to stabilize the spine to prevent compression, distraction, or translation of the spinal cord during a spinal correction. 
       FIG.  9 A  shows a manipulator rod  905  and a manipulator clamp  915  with the stabilizer assembly  200 . While the manipulator rod  905  and the manipulator clamp  915  are shown and discussed in conjunction with the stabilizer assembly  200 , they can be used in conjunction with other embodiments of the stabilizer assembly, such as stabilizer assembly  100  (not shown). The manipulator rod  905  is shown coupled to the hinge  205  of the stabilizer assembly  200 , and the manipulator clap  915  is shown coupled to the stabilizing rod  230  of the stabilizer assembly  200  and to the spinal rod  140 . The manipulator clamp  915  may also be coupled to the stabilizing rod  225  of the stabilizer assembly  200  and to the spinal rod  135 . 
       FIG.  9 B  shows the manipulator rod  905  in position to be coupled to the hinge  205  of the stabilizer assembly  200 . The manipulator rod  905  includes a grip  907  affixed at a proximate end of the manipulator rod  905 , a body  909  and a coupling mechanism  911  affixed at a distal end of the manipulator rod  905 . In the exemplary embodiment shown, the coupling mechanism  911  includes a threaded recess (not shown) configured to be screwed onto a threaded hinge bolt  913 . Once coupled to the hinge  205 , the manipulator rod  905  can be used to manipulate the stabilizer assembly  200 . The body  909  may be straight or curved may have a circular, elliptical, triangular, square, pentagonal, hexagonal, or other polygonal cross section. 
       FIG.  9 C  shows a side view of the manipulator clamp  915  coupled to the stabilizing rod  230  and the spinal rod  140 . The manipulator clamp  915  includes two clamp arms  917   a, b , that are rotatably coupled together. At a proximal end of the manipulator clamp  915 , the two clamp arms  917   a, b  engage each other in a disengagable ratchet mechanism  919 . At a distal end of the manipulator clamp  915 , each of the clamp arms  917   a, b  includes a gripping surface, gripping surfaces  921   a, b , respectively, with recesses to engage the stabilizing rod  230  and the spinal rod  140 . 
       FIG.  9 D  shows the distal end of the manipulator clamp  915  coupled to the stabilizing rod  230  and the spinal rod  140 . At the distal end of the manipulator clamp  915 , each of the clamp arms  917   a, b  includes a gripping surface, gripping surfaces  921   a, b , respectively ( 921   b  not shown) with recesses to engage the stabilizing rod  230  and the spinal rod  140 . 
       FIG.  9 E  shows the rod-bearing leaves  210  and  215  of the stabilizer assembly  200  separately. The rod-bearing leaf  215  includes a bolt hole  925  that is configured to receive a bolt  927  bearing a nut  929  such that the bolt  927  is retained by the rod-bearing leaf  210 . The bolt  927  couples the stabilizing rod  230  to the rod-bearing leaf  215 . Similarly, rod-bearing leaf  210  includes a bolt hole  931  that is configured to receive a bolt (not shown) bearing a nut (not shown) such that the bolt is retained by the rod-bearing leaf  210  to couple a stabilizing rod  225  (not shown) to the rod-bearing leaf  210 . 
       FIG.  9 F  shows the rod-bearing leaves  210  and  215  of the stabilizer assembly  200  coupled at the hinge  205 . In  FIG.  9 F , the rod-bearing leaves  210  and  215  are shown coupled by the hinge bolt  913 , with bolts  927  and  933 , bearing nuts  929  and  935 , respectively, partially inserted into the bolt holes  925  and  931  (not shown), respectively. 
     One skilled in the art of medical treatment of human hip ailments will recognize that the device for treating spinal maladies including stabilizer assembly  100 , stabilizer assembly  200 , and method  700  provide effective methods and systems that reduce risk for compression, distraction, or translation of the spinal cord during stabilization, manipulation, and fixation of a deformed spine subject to a vertebral column resection surgery or a spinal correction. 
     It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims. 
     All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
     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,” “at least one,” and “one or more than one.” 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 alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects. 
     As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. In embodiments of any of the compositions and methods provided herein, “comprising” may be replaced with “consisting essentially of” or “consisting of” As used herein, the phrase “consisting essentially of” requires the specified integer(s) or steps as well as those that do not materially affect the character or function of the claimed invention. As used herein, the term “consisting” is used to indicate the presence of the recited integer (e.g., a feature, an element, a characteristic, a property, a method/process step, or a limitation) or group of integers (e.g., feature(s), element(s), characteristic(s), property(ies), method/process(s) steps, or limitation(s)) only. 
     The term “or combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof” is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. 
     Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context. 
     As used herein, words of approximation such as, without limitation, “about,” “substantial” or “substantially” refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skill in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as “about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%. 
     All of the devices and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices and/or methods of this invention have been described in terms of particular embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims. 
     Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosure. Accordingly, the protection sought herein is as set forth in the claims below. 
     Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. 
     To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims to invoke 35 U.S.C. § 112(f) as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.