Abstract:
An intervertebral cage for spinal implants is provided. The intervertebral cage includes a front portion, a right lateral portion, a left lateral portion, a rear portion, a top portion and a bottom portion. A vertical dimension of the front portion is larger than a vertical dimension of the rear portion. A vertical dimension of the right portion is larger than a vertical dimension of the left portion. A vertical dimension of a connection between the left and rear portions is smaller than a vertical dimension of a connection between the right and front portions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of Korean Patent Application No. 10-2014-0169588, filed on Dec. 1, 2014, which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates generally to an intervertebral cage for spinal implants and, more particularly, to an intervertebral cage for spinal implants configured such that the cage can be mounted freely in front, lateral side or inclined direction relative to the vertebrae, wherein the front side has a trapezium face, the right lateral side and left lateral side are configured such that a left vertical line and a right vertical line are lengthened, and the length of the right vertical line of the left lateral is a shorter than that of the left vertical line of the right lateral, and the front side and the right lateral include a plurality of holes to which a tool is temporarily coupled. 
     2. Description of the Related Art 
     In general, an intervertebral cage for spinal implants is inserted into a disc-removed intervertebral gap and is an artificial prostheses apparatus for restoring and maintaining an interval between two vertebrae. Such an intervertebral cage for the spinal implants is currently formed in various shapes and is widely used to surge the vertebrae. 
     However, in order to replace a spinal disc due to abrasion of the disc, a frontal and lateral cage that is inserted at the position of the worn spinal disc has been currently developed and is used for the spinal disc operation. 
       FIGS. 1 to 3  are a perspective view, a plan view and a side view showing a conventional intervertebral cage, respectively. 
     As shown in  FIGS. 1 to 3 , a conventional intervertebral cage  10  has a width (horizontal length in the figures) and a height corresponding to the width and height of a disc ( 36  in  FIG. 4 ) positioned between vertebral bodies ( 32  and  34  in  FIG. 4 and 34  in  FIG. 5 ); a through hole  14  having a width vertically elongated is provided at the center of the intervertebral cage; small circular holes  17  and  18  are formed at the central portion of the front and back of the cage, respectively, so that these holes communicate with the through hole  14 ; a plurality of teeth  15 ,  16  and  19  are formed in an upper and bottom sides of the cage that are contacted with and adjacent to a lateral part of the through hole  14 ; and a groove  13  is formed at both laterals of a right lateral  11  of the cage. 
     The method of using the above-mentioned conventional lateral cage  10  will be described as follows: 
     Before the lateral cage  10  is inserted into a damaged disc of a patient whose a spinal disc is worn or damaged, granulated bone chips are mixed with the patient&#39;s bone marrow or blood and then inserted into the through hole  14  of the lateral cage  10  and hardened. Next, as shown in  FIG. 4 , the groove  13  formed at both sides of the right lateral  11  of the lateral cage  10  is picked up with pincers ( 20  in  FIG. 4 ) and the lateral cage is inserted into the position of the damaged disc  36  between the bodies  32  and  34  of the spine through an incised lateral side corresponding to the damaged disc of patients. At this time, the lateral cage may be inserted by knocking on the pincers using a kind of hammer. 
       FIG. 5  is a plan view showing the inserted lateral cage. The conventional lateral cage has a problem as follows: 
     First of all, a frontal cage may be used only in a frontal direction and a lateral cage may be used only in a lateral direction. The lateral cage cannot be replaced with the frontal cage during actual surgery, and if the frontal cage instead of the lateral cage is inserted by force in the case wherein there is a narrow space between the discs, it may cause damage to a vertebral disc. This results in complications such as non-union of the spine during use. 
     Also, since the height of the tip of a left lateral  12  of the lateral cage  10  that is first inserted into patient&#39;s spine during surgery, is formed to be substantially the same as that of the other part, a great amount of power must be applied between the vertebrae in the case wherein there is a narrow space between the discs and this may cause the vertebra board to be damaged. Further, if a great amount of power is applied, a bone chip  40  ( FIG. 5 ) may be lost before it is placed between the vertebrae and so complications such as non-union of the spine may be caused while the vertebral surgery time is elapsed. 
     Also,  FIGS. 6 and 7  show an intervertebral cage of the prior art (Japanese un-examined Laid-open publication No. 9-503416; Japanese patent application No. 199-511847). An intervertebral cage  50  comprises a pair of left and right semicircular lateral spacers  51 A and  51 B, a front and a rear central spacers  53 A and  53 B integrally fixed to each other by left and right fixing screws  55 . The intervertebral cage  50  is inserted between an upper intervertebral body  59 U and a lower intervertebral body  59 L after removal of a disc. A cavity  57  is formed by the central spacers  53 A and  53 B and the lateral spacers  51 A and  51 B. 
     The intervertebral cage  50  of the prior art has problems in that 1) the cage consists of a large number of components and has a complex structure and 2) the cage cannot secure enough between the vertebrae after the insertion between the vertebral bodies, because they do not have a projection for preventing a loss of the intervertebral cage. Further, the intervertebral cage  50  of the prior art is inserted between the upper body and the lower body from a frontal direction, but it is not inserted from the vertical direction to an inclined front side. Accordingly, an improved intervertebral cage is required. That is, the intervertebral cage of the prior art has separate configurations for cases in which there is a front cage, a lateral cage, or an inclined cage, etc. and other configurations of the auxiliary apparatuses are also used as the other components. 
     SUMMARY 
     Aspects of the present invention are intended to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an object of the present invention is to provide an intervertebral cage that may be inserted into vertebral spines in the front, lateral and inclined direction relative to the vertebrae in order to be able to freely select the insertion direction of the intervertebral cage in accordance with the needs of a user. Ultimately, the present invention is intended to reduce the costs of consumable medical supplies. 
     In accordance with an aspect of the present invention, an intervertebral cage for spinal implants is provided. The intervertebral cage comprises: a front side  10 ; a right lateral  20 ; a left lateral  30 ; a rear side  40 ; a plane  50 ; and a bottom  60  configured to have a shape of “           ” (Chinese character) in which vertical holes are formed on both sides,
     wherein the front side  10  has a trapezium face on the left side and a rectangle face on the right side, 
     the right lateral  20  is disposed on the right of the front side and comprises a lengthened left vertical line, a sloping upper line and lower line and a shortened right vertical line, 
     the intervertebral cage left lateral  30  is disposed on the left of the front side of the intervertebral cage and comprises a lengthened right vertical line, a sloping upper line and lower line and a shortened left vertical line in the form of trapezium, the right lateral vertical line disposed on the left side being shorter than the left vertical line disposed on the right side, 
     the rear side  40  is disposed on the back of the front side and has a trapezium face on the left side and a rectangle face on the right side, and 
     the plane  50  and the bottom  60  are disposed on the upper and lower parts of the front side and further comprise a slippage preventing means for improving the contact of vertebrae. 
     A plurality of striking-auxiliary holes  1  for temporarily coupling and striking a tool are formed along the front side  10  and the right lateral  20  in order to allow the intervertebral cage to be inserted between the vertebrae. 
     The slippage preventing means  70  may comprise an embossing structure  70   a  having a concave portion and a convex portion, the concave and the convex portions being sequentially formed, or a vacuum compressed structure  70   b  having a truncated cone in which the concave portion is formed on the inside so as to enable vacuum compression. 
     The slippage preventing means  70  may further comprise a hooked structure  70   c  to be not easily moved backward when the intervertebral cage is coupled between the vertebrae. 
     The hooked structure  70   c  may comprise a fixing portion  70   d  and a movable chain hook  70   e , the chain hook  70   e  being installed to be self-rotated. 
     The slippage preventing means  70  may comprise an embossing structure  70   f  having a concave portion and a convex portion, the concave and the convex portions being sequentially formed, and the embossing structure  70   f  being formed on an inner lateral  10   a  of the intervertebral cage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1 to 7  show a structure of a conventional intervertebral cage; 
         FIG. 8  is a perspective view illustrating an intervertebral cage in accordance with the present invention; 
         FIG. 9  shows six sides of an intervertebral cage in accordance with the present invention; 
         FIG. 10  is a view illustrating a slippage preventing means in accordance with a first embodiment of the present invention; 
         FIG. 11  is a view illustrating a slippage preventing means in accordance with a second embodiment of the present invention; 
         FIG. 12  is an enlarged view showing in detail a primary part of  FIG. 11 ; 
         FIG. 13  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted in a direction from the front side to the rear side; 
         FIG. 14  is a picture showing the inserted state of the intervertebral cage in which the intervertebral cage has been inserted in a direction from the front side to the rear side; 
         FIG. 15  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted in the diagonal direction; 
         FIG. 16  is a picture showing the inserted state of the intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted in the diagonal direction; 
         FIG. 17  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted from the side; 
         FIG. 18  is a picture showing the inserted state of the intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted from the side; and 
         FIG. 19  is a perspective view showing a slippage preventing means which has been formed in an inner lateral of an intervertebral cage in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the method of operation of a preferred embodiment of the present invention will be described with reference to the accompanying drawings and the description. However, the drawings and the description only illustrate a preferred method of implementation from among several such methods for the purpose of effectively describing the features of the present invention, and the present invention is not limited only to these drawings and description. 
     Furthermore, in describing the present invention, if known functions and constructions are deemed to make the gist of the invention unnecessarily complex, the detailed description thereof will be omitted. 
     Further, the terms to be described later are those that are defined in consideration of the functions in the present invention, and the definitions can differ depending on the intention or practice of users or operators. Therefore, the definitions must be considered based on the entire content of the present invention. 
     Further, in the preferred embodiment of the present invention to be described below, if the functional configuration of each system is already included, or have been commonly used in the technical field to which the invention pertains, in order to explain the technical components of the present invention efficiently the description thereof will be omitted. Further, the preferred embodiment is described, based on the functional configuration which must additionally be included for carrying out the present invention. Among the functional components omitted and not shown below, the functional components already used in the prior art will be easily understood by those of ordinary skill in the art. Further, the relationship between the components omitted as above and the components added for carrying out the present invention will be clearly understood by those of ordinary skill in the art. 
     Also, the following examples are to illustrate the important technical features of the present invention efficiently, and the terms used herein may be properly modified to so that those of ordinary skill in the art can easily understand them. However, the invention is not limited thereto. 
     In conclusion, the technical idea of the present invention is determined by the claims, and the following embodiments are only a means for efficiently explaining the technical idea of the present invention to those of ordinary skill in the art. 
       FIG. 8  is a perspective view illustrating an intervertebral cage in accordance with the present invention.  FIG. 9  shows six sides of an intervertebral cage in accordance with the present invention. 
     As shown in  FIGS. 8 and 9 , the intervertebral cage  100  in accordance with the present invention has a cuboid with trapezoidal cross-section wherein the front side is thick and the rear side is thin, and the right side is thick and the left side is thin. As a result, when the intervertebral cage  100  is inserted into a spine  200  ( FIG. 13 ), the cage can be coupled to the spines by insertion from the front side to the rear side or by the insertion in a 45-degree oblique direction from the left to the right. Also, a reversed intervertebral cage may be coupled to the spine by insertion in a 45-degree oblique direction from the right to the left. Further, the intervertebral cage of the present invention may be inserted into a lateral of the spine from the left to the right and vice-versa. 
     In the following, components of the present invention will be described in detail with reference to  FIGS. 10 to 12 . 
       FIG. 10  is a view illustrating a slippage preventing means in accordance with a first embodiment of the present invention.  FIG. 11  is a view illustrating a slippage preventing means in accordance with a second embodiment of the present invention.  FIG. 12  is an enlarged view showing in detail a primary part of  FIG. 11 . 
     The intervertebral cage  100  of the present invention is a substantially cuboid configured to have a shape of “           ” in which vertical holes (a) are formed on both sides.
     A front side  10  of the intervertebral in accordance with the present invention has a trapezium face on the left and a rectangle face on the right. 
     A right lateral  20  is disposed on the right of the front side and comprises a lengthened left vertical line, a sloping upper line and lower line and a shortened right vertical line configured to form a trapezium. 
     A rear side  40  is disposed on the back of the front side and has a trapezium face on the left and a rectangle face on the right. 
     A plane  50  and a bottom  60  are disposed on the upper and lower parts of the front side and further comprises a slippage preventing means for improving a contact of vertebrae. 
     Also, a plurality of striking-auxiliary holes  1  for temporarily coupling and striking a tool are formed along the front side  10  and the right lateral  20  in order to allow the intervertebral cage to be inserted between the vertebrae. 
     On the other hand, in one embodiment of the present invention, the slippage preventing means  70  may be configured in various patterns and may comprise an embossing structure  70   a  having a concave portion and a convex portion which are sequentially formed (see  FIG. 9 ); a vacuum compressed structure  70   b  having a truncated cone in which the concave portion is formed on the inside so as to enable vacuum compression (see  FIG. 10 ); and a hooked structure  70   c  so that it is not easily moved backward when the intervertebral cage is coupled between the vertebrae (see  FIG. 11 ). 
     Especially, as shown in  FIG. 12 , the hooked structure  70   c  may comprise a fixing portion  70   d  and a movable chain hook  70   e , the chain hook  70   e  being installed to be self-rotated. When the intervertebral cage  100  is coupled in the front side, the tip of the movable chain hook  70   e  may be rotated toward the direction opposite to the inserting direction and configured to not be prevented by the insertion. In contrast, when the intervertebral cage is released, the tip of the movable chain hook  70   e  is hooked to a flat contacting surface of the spine  200  and configured to be not easily moved. Likewise, when the intervertebral cage  100  is coupled in an oblique direction, the tip of the movable hook  70   e  may be obliquely arranged toward the direction opposite to the inserting direction and configured to allow the intervertebral cage to be softly inserted into the spine  200 . 
     In contrast, when the intervertebral cage is released, the tip of the movable hook  70   e  is hooked to the flat contacting surface of the spine  200  and configured to be not easily moved. Also, in the case of a lateral insertion of the intervertebral cage from a rear end of the spine to a lateral direction, the tip of the movable hook  70   e  may be rotated toward the direction opposite to the insertion direction and configured to be softly inserted into the spine. Likewise, when the intervertebral cage is released, the tip of the movable hook  70   e  is hooked to the flat contacting surface of the spine  200  and configured to be not easily moved. 
     In the following, an assembling method of the intervertebral cage in accordance with the present invention will be described in detail with reference to  FIGS. 13 to 19  as follows: 
       FIG. 13  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the cage has been inserted in a direction from the front side to the rear side.  FIG. 14  is a picture showing the inserted state of the intervertebral cage in which the cage has been inserted in a direction of from a front side to a rear side.  FIG. 15  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted in the diagonal direction.  FIG. 16  is a picture showing the inserted state of the intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted in the diagonal direction.  FIG. 17  is a picture showing the insertion operation of an intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted from the side.  FIG. 18  is a picture showing the inserted state of the intervertebral cage in accordance with the present invention in which the intervertebral cage has been inserted from the side. 
     The intervertebral cage  100  of the present invention may be inserted and coupled to the spine  200  through a front side and an inclined plane of the spine or from a rear side of the spine to a left direction and a right direction. The intervertebral cage  100  may have a form in which a front side and a left lateral are high and a rear side and a right lateral are low and have a shape of “           ” in which two vertical holes (a) are formed.
     Accordingly, a connecting portion between a left lateral and a rear may be formed at the thinnest section, while a connection portion between the front and the right lateral may be formed at the thickest section. As a result, when the intervertebral cage  100  is coupled to the spine  200  in an oblique direction, the intervertebral cage may be easily inserted and coupled to a left oblique surface by means of the insertion from the thinner portion to the thicker portion. In case of a reversed intervertebral cage about a horizontal axis, since the left and right laterals are reversed, the reversed intervertebral cage may be easily inserted and coupled. 
     When the intervertebral cage  100  is coupled to the spine  200  in an oblique direction, the intervertebral cage  100  may be easily coupled with the spine by knocking the cage with a tool through a plurality of strike aids holes  1  positioned in the corner direction. Also, when the intervertebral cage  100  is inserted from the frontal direction to a rear direction, since the front is thick and the rear is thin, the intervertebral cage may be easily inserted and coupled. Likewise, when the intervertebral cage  100  is inserted from the frontal direction, the intervertebral cage may be easily coupled with the spine  200  by knocking the cage with the tool through the plurality of striking-auxiliary holes  1  positioned in the front Also, when the intervertebral cage  100  is coupled with the spine  200  from the rear side  40  to the left lateral, since the left lateral  30  is thin and the right lateral  20  is thick, the intervertebral cage  100  may be easily coupled with the spine  200  from the rear side  40  to the left lateral. It is of course possible that, when the intervertebral cage  100  is inserted and coupled in the right lateral, the intervertebral cage  100  may be reversed about a horizontal axis. Also, when the intervertebral cage  100  is coupled in a left lateral direction, the intervertebral cage  100  may be easily coupled with the spine  200  by knocking the cage with a tool through a plurality of strike aids holes  1  positioned in the right lateral  20 . 
     Hereinafter, an operating method of the intervertebral cage in accordance with the present invention will be described in detail as follows: 
     The intervertebral cage  100  of the present invention may have a shape of “           ” in which two vertical holes (a) are formed, a connecting portion between the left lateral  30  and the rear side  40  being formed at the thinnest section, while a connection portion between the front side  10  and the right lateral  20  being formed at the thickest section.
     When the intervertebral cage  100  of the present invention is inserted and coupled to the spine, because the thickness of the front side  10  of the intervertebral cage is high, while that of the rear side  40  thereof is low, the intervertebral cage  100  may be inserted from the frontal direction to the rear direction of the spine  200 . Further, because the thickness of the left lateral  30  is low, while that of the right lateral  20  is high, the intervertebral cage  100  may be inserted from the left lateral direction to the right lateral direction of the spine  200 . Also, because the connecting portion between the left lateral  30  and the rear side  40  of the intervertebral cage  100  is formed at the thin section, while the connection portion between the front side  10  and the right lateral  20  thereof is formed at the thick section, the intervertebral cage  100  may be inserted from the right oblique direction to the left oblique direction of the spine  200 . It is of course possible that, when the intervertebral cage  100  is reversed about a horizontal axis, the intervertebral cage may be inserted from the left lateral oblique direction to the right lateral oblique direction or from the right lateral oblique direction to the left lateral oblique direction. Also, the intervertebral cage may not slip when the intervertebral cage  100  of the present invention is coupled to the spine  200  by further including a slippage preventing means  70  formed in an upper portion and a lower portion of the intervertebral cage. 
     That is, the slippage preventing means  70  may be formed between the spines  200  in order to prevent the possibility that the intervertebral cage  100  coupled between the spines  200  could be separated by slippage. The slippage preventing means  70  may selectively comprise an embossing structure  70   a  having a concave portion and a convex portion, the concave and the convex portions being formed in order, a vacuum compressed structure  70   b  having a truncated cone in which a concave portion is formed on inside so as to be vacuum compressed, or a hooked structure  70   c  to not be easily moved backward when the cage is coupled between the vertebrae. As a result, the intervertebral cage  100  of the present invention may be easily coupled without slipping between the spines  200  during the coupling of the intervertebral cage. 
     Further, the embossing structure  70   f  having a concave portion and a convex portion, the concave and the convex portions being sequentially formed, may be formed at an inner lateral  10   a  of the intervertebral cage  100 . Both insides of the embossing structure  70   f  are hollow, into which space an autograft or an allograft is inserted so as to advantageously achieve a bony fusion. Accordingly, the intervertebral cage of the present invention inserted to the spines may not separate from the spines by the autograft or the allograft positioned insides of the embossing structure so as to effectively achieve the bony fusion. 
     According to the present invention, when the intervertebral cage  100  is coupled with the spine  200  in an oblique direction, the intervertebral cage may be easily inserted and coupled to the left oblique surface. 
     As described above, according to an intervertebral cage in accordance with various embodiments of the present invention, the intervertebral cage may be inserted in every face, i.e., a front side, a lateral side and an inclined plane of a spine and configured such that it is possible to freely select the inserting direction of intervertebral cage in accordance with the needs of a user. This results in a maximization of the advantages of such operation. 
     Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.