Abstract:
An apparatus for interspinous spinal fixation is disclosed, which includes a main body having an end thereof as a distal end, and another end thereof as a proximal end, a cross section of the main body being of an annular or quasi-annular structure. A first joining point and a second joining point are provided at the distal end that are symmetric to each other relative to an opening of the annular or quasi-annular structure, while a third joining point and a fourth joining point are provided at the proximal end that that are symmetric to each other relative to the opening of the annular or quasi-annular structure. A first lateral piece, a second lateral piece, a third lateral piece, and a fourth lateral piece are joined with the first, the second, the third, and the fourth joining points of the main body, such that the first and the second lateral pieces can rotate axially about the first and the second joining points, thereby rotating from a folded position on the main body to an extended position; and the third and the fourth lateral pieces can rotate axially about the third and the fourth joining points, thereby rotating from a folded position on the main body to an extended position.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to an apparatus for stabilizing the human spine, and more particularly to a spinal fixation apparatus to be inserted between neighboring vertebrae. 
       DESCRIPTION OF PRIOR ART 
       [0002]    Spinal diseases, disorders of the facet joint and related tissues surrounding the spine are often accompanied by severe pain, and such disorders are frequently caused by several factors, which include the degeneration and aging of spinal discs. Moreover, the disorders may further evolve into more serious symptoms like dislocation or herniation of vertebrae. Consequently, any minor movements between the neighboring vertebrae can cause severe pain to an afflicted person while moving around. 
         [0003]    Spinal fixation apparatuses to be inserted between vertebrae has been introduced before, including patents like TW-590756, TW-00520986, and TW-00542712; in which a tether was used to securely hold a spinal fixation apparatus between the spinous process and the interspinous space in place. However, an open surgery is required for inserting this type of spinal fixation apparatus, which is more invasive and structurally complicated. Subsequently, the surgery is more time-consuming and leaves a relatively larger wound on the patient. 
       SUMMARY OF THE INVENTION 
       [0004]    A primary objective of the present invention is to provide an interspinous spinal fixation apparatus. 
         [0005]    The interspinous spinal fixation apparatus of the invention stabilizes two neighboring vertebrae by extending lateral pieces thereof. 
         [0006]    Another objective of the present invention is to provide a flexible interspinous spinal fixation apparatus. 
         [0007]    Another objective of the present invention is to provide an interspinous spinal fixation apparatus that has easily extendable lateral pieces. 
         [0008]    Yet another objective of the present invention is to provide an interspinous spinal fixation apparatus having lateral pieces that may be extended by rotating. 
         [0009]    Yet another objective of the present invention is to provide an interspinous spinal fixation apparatus having dual-axis lateral pieces that may be extended by rotating. 
         [0010]    A further objective of the present invention is to provide an interspinous spinal fixation apparatus that requires less surgery time. 
         [0011]    An interspinous spinal fixation apparatus, comprising: 
         [0012]    a main body having an end thereof as a distal end, and another end thereof as a proximal end, wherein a cross section of the main body is of an annular or quasi-annular structure, and a first joining point and a second joining point are provided at the distal end that are symmetric to each other relative to an opening of the annular or quasi-annular structure, while a third joining point and a fourth joining point are provided at the proximal end that that are symmetric to each other relative to the opening of the annular or quasi-annular structure; and 
         [0013]    at least four lateral pieces, including a first lateral piece, a second lateral piece, a third lateral piece, and a fourth lateral piece, and an end of each of the lateral pieces is an extending end, whereas another end thereof is an joining end, wherein the joining ends of the first, the second, the third, and the fourth lateral pieces are used for joining with the first, the second, the third, and the fourth joining points of the main body, such that the first and the second lateral pieces can rotate axially about the first and the second joining points, thereby rotating from a folded position on the main body to an extended position. 
         [0014]    The aforesaid main body may be fitted between the spinous processes of two neighboring vertebrae by modifying sizes and assemblies thereof. The main body may be fabricated by using any suitable materials, and is preferably made of biocompatible materials, such as metals (for example, stainless steel, titanium, aluminum, or metal alloys made of two or more metals), plastics, polymers, rubber, ceramics, natural tissues (such as bones), or composite materials (which are made of two or more than two materials). For judging whether a material is suitable for making the main body or not, a variety of factors may be considered, which include but not limited to the ability of withstanding sterilization, the ability of withstanding forces exerted thereupon, weight, durability, and the ability of combining with the lateral pieces and implantable sleeves. 
         [0015]    The aforesaid annular or quasi-annular structure may be an open ring, a closed ring, or a partially open ring, wherein the open ring may be open from an opening of the distal end to an opening of the proximal end of the main body, as indicated in  FIG. 7   a;  whereas the closed ring may be closed from an opening of the distal end to an opening of the proximal end of the main body, which appears as a closed-off O-shaped ring; the partially open ring may be partially closed and partially open from an opening of the distal end to an opening of the proximal end of the main body; the open ring is preferably used among the aforesaid rings. 
         [0016]    The aforesaid main body may be any type of cylindrical bodies having a cross section that is an annular or quasi-annular structure. Moreover, a center of the annular or quasi-annular structure is a pivot hole, and the pivot hole may be of any shapes; such as circular, elliptical, or polygonal, and is preferably circular. 
         [0017]    The above-mentioned open ring or partially open ring may be any type of cylindrical bodies having a cross section that is a C-shaped ring or quasi C-shaped ring structure. Furthermore, a center of the C-shaped ring or quasi C-shaped ring structure is a pivot hole, and the pivot hole may be of any shapes; such as circular, elliptical, or polygonal, and is preferably circular. 
         [0018]    The above-mentioned open ring or partially open ring of the main body also has a gap as an opening, which is used to allow a spot where the spinal fixation apparatus is inserted to be flexibly compressed after surgery. 
         [0019]    With regard to the aforesaid main body, the annular or quasi-annular structure at both sides of the distal end thereof may also include a group of correspondingly disposed safeguard mechanisms, which are the first safeguard mechanism and the second safeguard mechanism, wherein the first and the second safeguard mechanisms may be integrally formed with the main body, or integrally combined with the main body by using any of the previously known methods of combination (such as by clasping or screwing), and it is more preferable to have the first and the second safeguard mechanisms integrally formed with the main body, so as to secure the first and the second lateral pieces when they are extended to designated positions. 
         [0020]    In regard to the aforesaid main body, the annular or quasi-annular structure at both sides of the proximal end thereof may also include a group of correspondingly disposed safeguard mechanisms, which are the third safeguard mechanism and the fourth safeguard mechanism, wherein the third and the fourth safeguard mechanisms may be integrally formed with the main body, or integrally combined with the main body by using any of the previously known methods of combination (such as by clasping or screwing), and it is more preferable to have the third and the fourth safeguard mechanisms integrally formed with the main body, so as to secure the third and the fourth lateral pieces when they are extended to designated positions. 
         [0021]    The aforesaid first, second, third, and fourth safeguard mechanisms may be any of the previously known safeguard methods, such as the use of pins, protruding blocks, and stoppers. 
         [0022]    The aforesaid main body may further include a fixing mechanism for securing the main body while rotating the lateral pieces, so that the main body would not become loosened off the interspinous space while the lateral pieces are rotated. In addition, the fixing mechanism may be any of the previously known fixing mechanisms, such as fixing holes for holding clamps that can secure the main body (please see  FIG. 1 ). 
         [0023]    The aforesaid main body may further be fitted with an implantable sleeve at the distal end thereof, so as to allow the main body to be inserted into a patient during surgery and firmly secure the lateral pieces. The implantable sleeve may be fabricated by using any suitable materials, and is preferably made of biocompatible materials, such as metals (for example, stainless steel, titanium, aluminum, or metal alloys made of two or more metals), plastics, polymers, rubber, ceramics, or composite materials (which are made of two or more than two materials). For judging whether a material is suitable for making the implantable sleeve or not, a variety of factors may be considered, which include but not limited to the ability of withstanding sterilization, the ability of withstanding forces exerted thereupon, weight, durability, and the ability of combining with the lateral pieces and the main body. Moreover, the implantable sleeve may be integrally formed with the main body, or integrally combined with the main body by using any of the previously known methods of combination (such as by clasping or screwing), and it is more preferable to have the implantable sleeve integrally formed with the main body. The implantable sleeve may be of any shapes, and is preferably of a conical shape. 
         [0024]    The aforesaid main body may further be fitted with an implantable sleeve at the proximal end thereof, so as to allow the lateral pieces to be firmly secured after they are rotated to designated positions. The implantable sleeve may be fabricated by using any suitable materials, and is preferably made of biocompatible materials, such as metals (for instance, stainless steel, titanium, aluminum, or metal alloys made of two or more metals), plastics, polymers, rubber, ceramics, or composite materials (which are made of two or more than two materials). For judging whether a material is suitable for making the implantable sleeve or not, a variety of factors may be considered, which include but not limited to the ability of withstanding sterilization, the ability of withstanding forces exerted thereupon, weight, durability, and the ability of combining with the lateral pieces and the main body. Moreover, the implantable sleeve may be integrally combined with the main body by using any of the previously known methods of combination (such as by clasping or screwing). 
         [0025]    The aforesaid main body may include four or more than four lateral pieces, wherein the lateral pieces may have the third and the fourth lateral pieces being fixed at the extended position, and have the first and the second lateral pieces being able to be rotated to the extended position; or the first, the second, the third, and the fourth lateral pieces may all be able to be rotated from the folded position to the extended position, such that the lateral pieces may be allowed to surround and hold securely around at least one spinous process from two neighboring vertebrae, and is more preferable to have the first, the second, the third, and the fourth lateral pieces be able to be rotated from the folded position to the extended position. 
         [0026]    The aforesaid first and second joining points are correspondingly disposed at the opening of the annular or quasi-annular structure on the distal end of the main body. In addition, the first and the second joining points may be integrally combined with the joining ends of the first and the second lateral pieces by using any of the previously known methods of combination (such as by clasping, screwing, or locking), such that the first and the second lateral pieces may centrally rotate about the first and the second joining points. 
         [0027]    The aforesaid third and fourth joining points are correspondingly disposed at the opening of the annular or quasi-annular structure on the proximal end of the main body. Moreover, the third and the fourth joining points may be integrally combined with the joining ends of the third and the fourth lateral pieces by using any of the previously known methods of combination (such as by clasping, screwing, or locking), such that the third and the fourth lateral pieces may be fixed at the extended position or centrally rotated about the third and the fourth joining points, and is more preferable to have the third and the fourth lateral pieces being able to centrally rotate about the third and the fourth joining points. 
         [0028]    The first and the third joining points may include a cylindrical hole that passes through the first and the third joining points and penetrates the main body, and a joining rod fitted through the cylindrical hole, wherein the joining ends of the first and the third lateral pieces are connected to two ends of the joining rod by clasping, screwing, and locking, thereby allowing the extending ends of the first and the third lateral pieces to be rotated axially about the joining rod. 
         [0029]    The aforesaid second and fourth joining points may include a cylindrical hole that passes through the second and the fourth joining points and penetrates the main body, and a joining rod fitted through the cylindrical hole, wherein the joining ends of the second and the fourth lateral pieces are connected to two ends of the joining rod by clasping, screwing, and locking, thereby allowing the extending ends of the second and the fourth lateral pieces to be rotated axially about the joining rod. 
         [0030]    The aforesaid lateral pieces are not limited in shapes thereof, and are preferably in a form of apertures in the annular or quasi-annular structure that does not interfere with the main body. The lateral pieces may be fabricated by using any suitable materials, and is preferably made of biocompatible materials, such as metals (for example, stainless steel, titanium, aluminum, or metal alloys made of two or more metals), plastics, polymers, rubber, ceramics, natural tissues (such as bones), or composite materials (which are made of two or more than two materials). For judging whether a material is suitable for making the lateral pieces or not, a variety of factors may be considered, which include the ability of being bent flexibly and plastically, and/or the ability of allowing the lateral pieces to be deformed, and the ability of retaining any shapes after being bent. 
         [0031]    The aforesaid lateral pieces may be further fitted with auxiliary lateral pieces at extending ends thereof, respectively, such that when the lateral pieces are extended, the auxiliary lateral pieces may be further extended, so as to lengthen the lateral pieces, thereby further securing the lateral pieces between neighboring vertebrae. 
         [0032]    The aforesaid first, second, third, and fourth lateral pieces may be rotated and extended outwardly from the main body by using an actuator, and then held correspondingly to at least one spinous process of the vertebrae. In addition, the lateral pieces may also include contact surfaces for engaging with opposite facets of two spinous processes of neighboring vertebrae. 
         [0033]    The aforesaid actuator may be formed as a key or key-like structure, which is inserted from the proximal end and rotated left and right, so as to allow the extending ends of the lateral pieces to be rotated to the extended position, thereby allowing the lateral pieces to surround and hold securely around at least one spinous process from two neighboring vertebrae. 
         [0034]    The invention has proposed an interspinous spinal fixation apparatus having lateral pieces that may be easily rotated, which only requires minimally invasive surgeries for insertion. In addition to being less invasive, it requires shorter surgery duration, and may be flexibly compressed. Therefore, the apparatus may allow for control over vertebrae without critically altering the anatomical structure of the spine, thus preventing patients afflicted with minor symptoms from suffering permanent damages. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0035]    The aforesaid objectives and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings, in which: 
           [0036]      FIG. 1  is a perspective view that shows a disassembled interspinous spinal fixation apparatus according to a preferred embodiment of the invention. 
           [0037]      FIG. 2   a  is a perspective view that shows the lateral pieces of  FIG. 1  in a folded state. 
           [0038]      FIG. 2   b  is a perspective view that shows the lateral pieces of  FIG. 1  in an extended state. 
           [0039]      FIG. 3   a  is a perspective view that shows an interspinous spinal fixation apparatus in a folded state according to another preferred embodiment of the invention. 
           [0040]      FIG. 3   b  is a perspective view that shows an interspinous spinal fixation apparatus in an extended state according to another preferred embodiment of the invention. 
           [0041]      FIGS. 4   a,    4   b,  and  4   c  are close schematic views that show three different shapes of pivot holes of the interspinous spinal fixation apparatus according to another preferred embodiment of the invention. 
           [0042]      FIGS. 5   a,    5   b,  and  5   c  are schematic views that show three different ways for combining the main body and the implantable sleeve according to a further preferred embodiment of the invention. 
           [0043]      FIGS. 6   a,    6   b,  and  6   c  are schematic views that show three different ways for combining the lateral pieces and the joining rod according to a further preferred embodiment of the invention. 
           [0044]      FIGS. 7   a  and  7   b  are schematic views that show two different ways for combining the lateral pieces and the main body according to a further preferred embodiment of the invention. 
           [0045]      FIGS. 8   a,    8   b,  and  8   c  are schematic views that illustrate three different actuators according to a further preferred embodiment of the invention. 
           [0046]      FIG. 9  is a schematic view that illustrates a way for implementing the interspinous spinal fixation apparatus and the actuator according to a further preferred embodiment of the invention. 
           [0047]      FIGS. 10   a,    10   b,    10   c,  and  10   d  are schematic views that illustrate the interspinous spinal fixation apparatus being implemented between neighboring vertebrae according to a further preferred embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0048]    The preferred embodiments of the invention will be further elucidated in the following text accompanied with the aforesaid drawings. 
         [0049]      FIG. 1  is a perspective view that shows a disassembled interspinous spinal fixation apparatus according to a preferred embodiment of the invention, which comprises a main body  100 . The main body  100  has a proximal end  120 ; a distal end opposite to the proximal end  120 , which cannot be seen in  FIG. 1  due to view angle; a third joining point  12  land a fourth joining point  122  of the proximal end  120 ; a first joining point and a second joining point of the distal end opposite to the third joining point  121  and a fourth joining point  122 , which cannot be seen in  FIG. 1  due to view angle; a third safeguard mechanism  123  and a fourth safeguard mechanism  124 of the proximal end  120 ; a first safeguard mechanism and a second safeguard mechanism of the distal end opposite to the third safeguard mechanism  123  and the fourth safeguard mechanism  124 , which cannot be seen in  FIG. 1  due to view angle; an opening  130 ; a pivot hole  140 ; a fixing mechanism  150 , which is a fixing hole for securely holding clamps; a first lateral piece  210 ; a second lateral piece  220 ; a third lateral piece  230 ; and a fourth lateral piece  240 . The first lateral piece  210  has a joining end  211 , an extending end  212 , a securing hole  213 , a joining hole  214 , and a groove  215 . The third later piece has a joining hole  234 . The joining hole  214  has parallel upper and lower surfaces, and left and right surfaces that are arc-shaped for combining with a joining rod. The second lateral piece  220 , the third lateral piece  230 , and the fourth lateral piece  240  are structurally identical to the first lateral piece  210 . The interspinous spinal fixation apparatus shown in  FIG. 1  further comprises an implantable sleeve  300 ; a first joining rod  500 ; and a second joining rod  600 . The sleeve  300  has a first connecting hole  310 , a second connecting hole (which cannot be seen in  FIG. 1  due to the blocking of the main body  100 ), and a connecting end  320 , wherein the implantable sleeve  300  is connected to the main body  100  via the connecting end  320 . The first joining rod  500  has an upper joining end  510 ; a lower joining end  520 ; and a rod body  530  therebetween, wherein the rod body  530  has two opposite sides formed as planar surfaces, so as to allow the rod body  530  to be fittingly combined with the first lateral piece  210  and the third lateral piece  230 , and prevent the first lateral piece  210  and the third lateral piece  230  from loosening during rotation. The second joining rod  600  is structurally identical to the first joining rod  500 , which has an upper joining end  610 ; a lower joining end  620 ; and a rod body  630  therebetween. Moreover, the first joining rod  500  may pass through the joining hole  234  of the third lateral piece  230 , continuously through the third joining point  121  and the first joining point of the main body  100 , and through the joining hole  214  of the first lateral piece  210 , thereby allowing a fastener at the upper joining end  510  of the first joining rod  500  to be combined with the first connecting hole  310  of the implantable sleeve  300 . The combination between the second lateral piece  220 , the fourth lateral piece  240 , the main body  100 , the second joining rod  600  and the implantable sleeve  300  are identical to that between the first lateral piece  210 , the third lateral piece  230 , the main body  100 , the first joining rod  500  and the implantable sleeve  300 . When the third lateral piece  230  is rotated and extended to an extended position, the third safeguard mechanism  123  is used to secure the third lateral piece  230  at the extended position. Furthermore, safeguard mechanisms of the first lateral piece  210  and the second lateral piece  220  (now shown in the drawings), and the safeguard mechanism  124  of the fourth lateral piece  240  are structurally identical to the third safeguard mechanism  123 . Similarly, each of the first lateral piece  210 , the fourth later piece  240 , and the second lateral piece  220  can be rotated and extended to an extended position, and can be secured at the extended position by the associated safeguard mechanism. 
         [0050]      FIG. 2   a  is a perspective view that shows the lateral pieces of  FIG. 1  in a folded state, in which the number  100  indicates the main body;  130  indicates the opening;  140  indicates the pivot hole;  150  indicates the fixing mechanism;  123  indicates the third safeguard mechanism;  124  indicates the fourth safeguard mechanism;  210 ,  220 ,  230 , and  240  separately indicate the first, the second, the third, and the fourth lateral pieces;  300  indicates the implantable sleeve,  320  indicates the connecting end;  500  indicates the first joining rod, and  600  indicates the second joining rod. 
         [0051]      FIG. 2   b  is a perspective view that shows the lateral pieces of  FIG. 1  in an extended state, wherein the numbers  100 ,  130 ,  140 ,  150 ,  123 ,  124 ,  210 ,  220 ,  230 ,  240 ,  300 ,  210 ,  500 , and  600  refer to the structures denoted by the same numbers in  FIG. 2   a.  Refer to  FIGS. 9 and 10  for the extending mechanisms of the apparatus. 
         [0052]      FIG. 3   a  is a perspective view that shows an interspinous spinal fixation apparatus in a folded state according to another preferred embodiment of the invention, which is similar to the apparatus shown in  FIG. 1  to  FIG. 2   b  except that the lateral pieces are further fitted with auxiliary lateral pieces, wherein like elements or parts are designated by like numerals. The number  100  is the main body;  130  is the opening;  140  is the pivot hole;  150  is the fixing mechanism;  123  is the third safeguard mechanism, and  124  is the fourth safeguard mechanism;  210 ,  220 ,  230 , and  240  are the first, the second, the third, and the fourth lateral pieces;  250 ,  260 ,  270 , and  280  are the first, the second, the third, and the fourth auxiliary lateral pieces;  300  is the implantable sleeve,  320  is the connecting end;  500  is the first joining rod, and  600  is the second joining rod. 
         [0053]      FIG. 3   b  is a perspective view that shows the interspinous spinal fixation apparatus of  FIG. 3   a  in an extended state, wherein the numbers  100 ,  130 ,  140 ,  150 ,  123 ,  124 ,  210 ,  220 ,  230 ,  240 ,  250 ,  260 ,  270 ,  280 ,  300 ,  320 ,  500 , and  600  refer to the structures denoted by the same numbers in  FIG. 3   a.    
         [0054]      FIGS. 4   a,    4   b,  and  4   c  are close schematic views that show three different shapes of pivot holes of the interspinous spinal fixation apparatus according to a preferred embodiment of the invention, in which the number  120  is the proximal end;  130  is the opening;  140  is the pivot hole;  123  is the third safeguard mechanism;  124  is the fourth safeguard mechanism;  121  is the third joining point;  122  is the fourth joining point. It can be observed in  FIG. 4   a  that the pivot hole  140  is circular, while the pivot hole  140  of  FIG. 4   b  is of identical width as the opening  130 , and pivot hole  140  of  FIG. 4   c  is elliptical. All of the pivot holes  140  shown in  FIGS. 4   a,    4   b,  and  4   c  allow an actuator to be inserted thereinto, and the lateral pieces may then be extended by rotating the actuator (please refer to  FIG. 8   a  to  FIG. 10   b ). 
         [0055]      FIGS. 5   a,    5   b,  and  5   c  are schematic views that show three different ways for combining the main body and the implantable sleeve according to a further preferred embodiment of the invention, wherein the number  100  is the main body;  124  is the fourth safeguard mechanism;  300  is the implantable sleeve, and  320  is the connecting end. Moreover,  FIG. 5   a  shows the implantable sleeve  300  is integrally formed with the main body  100 ; while  FIG. 5   b  shows the implantable sleeve  300  is combined with the main body  100  by clasping the connecting end  320  into the implantable sleeve  300 , and  FIG. 5   c  shows the implantable sleeve  300  is combined with the main body  100  by screwing the connecting end  320  into the implantable sleeve  300 . 
         [0056]      FIGS. 6   a,    6   b,  and  6   c  are schematic views that show three different ways for combining the lateral pieces and the joining rod according to a further preferred embodiment of the invention, wherein  210  is the first lateral piece;  211 ,  212 ,  213 ,  214 ,  215 , and  216  are respectively the joining end, the extending end, the securing hole, the joining hole, the groove, and a protruding block of the first lateral piece  210 . In addition,  230  is the third lateral piece;  231 ,  232 ,  234 , and  236  are respectively the joining end, the extending end, the joining hole, and the protruding block of the third lateral piece  230 ;  500  is the first joining rod;  510  and  520  are respectively the upper joining end and the lower joining end of the first joining rod  500 , while  530  is the rod body thereof.  FIG. 6   a  indicates that for the purpose of combination, the joining hole  214  of the first lateral piece  210  and the joining hole  234  of the third lateral piece  230  has parallel upper and lower surfaces, and left and right surfaces that are arc-shaped, and the rod body  530  of the joining rod  500  has two opposite sides formed as planar surfaces.  FIG. 6   b  indicates that for the purpose of combination, the protruding block  216  of the first lateral piece  210  and the protruding block  236  of the third lateral piece  230  are shaped as columns, so as to be fitted into the upper joining end  510  and the lower joining end  520  of the first joining rod  500 .  FIG. 6   c  indicates that for the purpose of combination, the protruding block  216  of the first lateral piece  210  and the protruding block  236  of the third lateral piece  230  are shaped as pins, so as to be fitted into the upper joining end  510  and the lower joining end  520  of the first joining rod  500 . 
         [0057]      FIGS. 7   a  and  7   b  are schematic views that show two different ways for combining the lateral pieces and the main body according to a further preferred embodiment of the invention, wherein  100  is the main body;  130  is the opening;  210 ,  220 ,  230 , and  240  are the first, the second, the third, and the fourth lateral pieces;  300  is the implantable sleeve;  320  is the connecting end, and  400  is a fixing sleeve. In addition,  FIG. 7   a  shows the first lateral piece  210  and the third lateral piece  230  are respectively connected to the upper joining end  510  and the lower joining end  520  of the first joining rod  500 ; the second lateral piece  220  and the fourth lateral piece  240  are respectively connected to the upper joining end  610  and the lower joining end  620  of the second joining rod  600 . The implantable sleeve  300  and the fixing sleeve  400  are both combined with the main body  100  by screwing, so as to further secure the first lateral piece  210 , the second lateral piece  220 , the third lateral piece  230 , and the fourth lateral piece  240  on the main body  100 . The first and third lateral pieces  210  and  230  are allowed to rotate about the first joining rod  500 ; and the second and the fourth lateral pieces  220  and  240  are allowed to rotated about the second joining rod  600 .  FIG. 7   b  shows the first lateral piece  210  and the third lateral piece  230  are respectively connected to the upper joining end  510  and the lower joining end  520  of the first joining rod  500  by clasping; the second lateral piece  220  and the fourth lateral piece  240  are respectively connected to the upper joining end  610  and the lower joining end  620  of the second joining rod  600  by clasping. The implantable sleeve  300  and the fixing sleeve  400  are both combined with the main body  100  by screwing, so as to further secure the first lateral piece  210 , the second lateral piece  220 , the third lateral piece  230 , and the fourth lateral piece  240  on the main body  100 . The first and third lateral pieces  210  and  230  are allowed to rotate about the first joining rod  500 ; and the second and the fourth lateral pieces  220  and  240  are allowed to rotated about the second joining rod  600 . 
         [0058]      FIGS. 8   a,    8   b,  and  8   c  are schematic views that illustrate three different actuators according to a further preferred embodiment of the invention, wherein  700  is an actuator;  710  is a fixing block;  720  is a rotating block;  730  is an aligning block, and  740  is a rod body. Moreover, the fixing block  710  is inserted into the implantable sleeve so as to support the actuator  700  in the main body, and the aligning block  730  is inserted into the opening of the main body so as to align the actuator in the main body; please refer to  FIGS. 9 and 10  for methods of operating the actuator  700 .  FIG. 8   a  shows the rod body is shaped as a column, and  FIG. 8   b  shows the rod body is arc-shaped, so as to increase friction between the rod body and the main body while inserting the rod body;  FIG. 8   c  shows the rod body is S-shaped, so as to increase friction between the rod body and the main body while inserting the rod body. 
         [0059]      FIG. 9  is a schematic view that illustrates a way for implementing the interspinous spinal fixation apparatus and the actuator according to a further preferred embodiment of the invention, wherein  100  is the main body;  120  is the proximal end of the main body  100 ;  123  and  124  are respectively the third and the fourth safeguard mechanisms of the proximal end  120 ;  130  is the opening of the main body  100 ;  140  is the pivot hole of the main body  100 ;  150  is the fixing mechanism of the main body  100 ;  210 ,  220 ,  230 , and  240  are the first, the second, the third, and the fourth lateral pieces;  300  is the implantable sleeve;  320  is the connecting end of the implantable sleeve  300 , in which the implantable sleeve  300  is integrally formed with the main body  100  via the connecting end  320 ;  500  and  600  are the first and the second joining rods, respectively;  700  is the actuator;  710  is the fixing block;  720  is the rotating block;  730  is the aligning block, and  740  is the rod body. 
         [0060]      FIGS. 10   a,    10   b,    10   c,  and  10   d  are schematic views that illustrate the interspinous spinal fixation apparatus being implemented between neighboring vertebrae according to a further preferred embodiment of the invention, wherein  120  is the proximal end of the main body;  123  and  124  are respectively the third and the fourth safeguard mechanisms of the proximal end  120 ;  130  is the opening of the main body;  230  and  240  are respectively the third and the fourth lateral pieces;  700  is the actuator;  710  is the fixing block;  720  is the rotating block;  800  is an upper vertebra;  810  is a spinous process;  900  is a lower vertebra, and  910  is also a spinous process.  FIG. 10   a  indicates that the interspinous spinal fixation apparatus of the invention is inserted between the spinous process  810  of the upper vertebra  800  and the spinous process  910  of the lower vertebra  900 .  FIG. 10   b  shows that the actuator  700  may be rotated, and the fourth lateral piece  240  is subsequently rotated by using the rotating block  720 .  FIG. 10   c  shows that the actuator  700  may be rotated, and the fourth lateral piece  240  is subsequently rotated to the extended position by using the rotating block  720 .  FIG. 10   d  shows that the actuator  700  may be rotated, and the third lateral piece  230  is subsequently rotated to the extended position by using the rotating block  720 . 
         [0061]    The present invention has been described with the preferred embodiments thereof and it is understood that many changes and modifications to the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.