Abstract:
An apparatus for fixing a cervical spine having a self tension part used in orthopedic surgery or neurosurgery when executing an anterior fixation operation on cervical spines is disclosed, including: an extension groove formed through a plate between the insertion holes and the center of the plate; a channel groove formed with stepped surfaces at both sides at the boundary of the insertion holes and the extension groove; a guide that is connected to the channel groove, rotates left/rightward in the channel groove and locks the screw to be inserted into the insertion holes; and a tension part that gives a pushing force the guide to be pushed toward the center of the plate and allows the guide to be rotated in the channel groove.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Patent Application No. 10-2012-85115, filed on Aug. 3, 2012 and Korean Patent Application No. 10-2013-87576, filed on Jul. 24, 2013, the disclosure of which is entirely incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to an apparatus for fixing a cervical spine having a self tension part, which is used for fixing a front of cervical spine in orthopedic surgery or neurosurgery, and more specifically, to an apparatus for fixing a cervical spine having a self tension part, which includes; an extension groove formed through a guide plate between an insertion hole and a center of the plate wherein a screw is inserted into one or more insertion holes that are formed through the plate; a tension part formed inside of the extension groove and giving force for pushing the guide toward the center of the guide plate; a channel groove provided at the boundary of the insertion holes and the extension groove and formed with stepped surfaces at both sides; and a guide that is connected to the channel groove and rotates left/rightward in the channel groove, and locks the screw to be inserted into the insertion holes while rotating front/rearward with the pushing force of the tension part. 
       BACKGROUND ART 
       [0003]    Generally, when treating cervical disc diseases, cervical disc, cervical syndrome, cervical fractures, etc. in orthopedic surgery or neurosurgery, each vertebral body forming cervical vertebrae has to be fixed not to move about, thus for the fixation, a apparatus for fixing a cervical spine which includes a plate of a flat shape and a screw for fixing the plate to the cervical vertebrae are used. fixing a cervical spine briefly, the affected part is incised at the anterior of a neck portion of a patient and cervical vertebrae is exposed, and then cervical disc of the affected part is removed and surgical object of a cage, etc. is inserted between the vertebral bodies from which disc is removed, and then the plate is positioned in a top vertebral body and a bottom vertebral body of the portion into which the cage is inserted and the plate is fixed with a screw. 
         [0004]    The apparatus for fixing a cervical spine, as operated above, will firmly fix the cage that is inserted between vertebral bodies with the fixing force of the screw and the sustaining force of the plate. 
         [0005]    However, the screw fixed to vertebral bodies may be unscrewed due to the activity of the patient and retreat from the plate backward, causing a vibration of the cage and deterioration of the patient&#39;s recovery. 
         [0006]    Therefore, in order to prevent phenomena in which the screw of the apparatus for fixing a cervical spine is unscrewed and retreats, “Neck Portion Plate System”(Disclosed Technology 1) has been disclosed in Korean Patent Laid-Open No. 10-2009-86387 and “Apparatus for Fixing Cervical Spine”(Disclosed Technology 2) has been disclosed in Korean Patent Laid-Open No. 10-2005-11167, as conventional arts. 
         [0007]    Disclosed Technology 1 is configured to include a rotation element that is installed to be inserted into a hole of a screw on a plate of a cervical plate system, and Disclosed Technology 2 is configured to include a head fixing member to be hooked over the head of a fixing screw, between insertion holes of fixation screws formed on the plate. 
         [0008]    However, in technologies for fixing a cervical spine according to the conventional arts, the rotation element (Disclosed Technology 1) for preventing retreatment of the screw and the head fixing member (Disclosed Technology 2) have to be used essentially, thereby increasing the number of components, making the structure and the operation thereof to be complicated, and thus manufacturing cost of the apparatus for fixing a cervical spine will increase and there may be a possibility of erroneous operation of the apparatus. 
         [0009]    The invention disclosed in this background of the invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention has been made in an effort to solve the above-described problems associated with prior art and it is an object of the present invention to provide an apparatus for fixing a cervical spine in which a retreatment phenomenon of a screw can be prevented by firmly fixing the screw that is inserted at various angles to a plate at an operation by using, and further the operation with the apparatus for fixing a cervical can be performed easily 
         [0011]    In order to achieve the object of the present invention, the present invention provides an apparatus for fixing a cervical spine having a self tension part, including: an extension groove formed through a plate between the insertion holes and the center of the plate; a channel groove formed with stepped surfaces at both sides at the boundary of the insertion holes and the extension groove; a guide that is connected to the channel groove, rotates left/rightward in the channel groove and locks the screw to be inserted into the insertion holes; and a tension part that gives a pushing force the guide to be pushed toward the center of the plate and allows the guide to be rotated in the channel groove. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]    The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0013]      FIG. 1  is a perspective view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention; 
           [0014]      FIG. 2  is a plan view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention; 
           [0015]      FIG. 3  is an exploded perspective view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention; 
           [0016]      FIGS. 4 to 5  are views showing operating conditions of the guides of an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention; 
           [0017]      FIG. 6  is a view showing an operating condition of an apparatus for fixing a cervical spine inserted with a screw according to a first exemplary embodiment of the present invention; 
           [0018]      FIG. 7  is a perspective view showing an apparatus for fixing a cervical spine inserted with a screw according to a first exemplary embodiment of the present invention; 
           [0019]      FIG. 8  is a perspective view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention; 
           [0020]      FIG. 9  is a plan view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention; 
           [0021]      FIG. 10  is a bottom view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention; 
           [0022]      FIG. 11  is an exploded perspective view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention; 
           [0023]      FIG. 12  is a sectional view taken along line A-A of  FIG. 9 ; 
           [0024]      FIG. 13  is a view showing an operating condition of a guide of an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention; and 
           [0025]      FIG. 14  is a view showing an operating condition of an apparatus for fixing a cervical spine inserted with a screw according to a second exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Hereinafter, an apparatus for fixing a cervical spine having a self tension part according to an exemplary embodiment of the present invention will be described, referring to the accompanying drawings. 
         [0027]    However, the disclosed drawings are provided exemplarily for transferring the spirit of the present invention to a skilled ordinary person. Accordingly, the present invention is not limited to the drawings referred below and may be implemented with other aspect. 
         [0028]    Additionally, the terms used in the present invention, unless defined as other meanings, have ordinary meanings such that a person who has an ordinary skill in the art to which the present invention pertains can understand them, and the detailed description of a publicly known function and constitution that may obscure a gist of the present invention will be omitted in the following. 
         [0029]      FIG. 1  is a perspective view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention, and  FIG. 2  is a plan view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention, and  FIG. 3  is an exploded perspective view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention. 
         [0030]    Referring to the drawings, the apparatus for fixing a cervical spine  1  according to a first exemplary embodiment of the present invention is provided with a plate  10  of a flat shape. 
         [0031]    The plate  10  may be made preferably of a rigid metal such as Titanium, etc. 
         [0032]    The plate  10  is shaped as a quadrangle wherein each edge thereof is curved. Further, inside of each edge of the plate  10 , one or more insertion holes  20  into which screws  100  for fixing the plate  10  to the cervical spine are inserted are perforated through the plate  10 . 
         [0033]    In the first exemplary embodiment shown in the drawings, four insertion holes  20  are provided, however the number of the insertion hole is not limited thereto, and thus two, six, eight or more insertion holes may be provided depending on the fixation level of a cervical spine fixing operation. 
         [0034]    Further, an inner wall  21  of the insertion hole  20  is curved to be meshed with the shape of a head  101  of a screw  100 , which will be described later. 
         [0035]    Additionally, an extension groove  50  is provided through the plate  10  between the insertion holes  20  and the center of the plate  10 , and at the boundary of the insertion holes  20  and the extension groove  50 , a channel groove  22  is formed with stepped surfaces  23  each having a predetermined height from the surface of the plate  10  at both sides. 
         [0036]    A guide  30  to be described later is inserted into the channel groove  22 , and the inserted guide  30  may be rotated right/leftward in the channel groove  22  while following the entering direction of the screw  100 . 
         [0037]    The guide  30  is shaped as an alligator clip wherein it is formed integrally by connecting an upper jaw  31  and a lower jaw  32  in flat shapes, which are extended horizontally, with a connective surface  33  that is extended vertically. 
         [0038]    The guide  30  as described above is connected to the plate such that the channel groove  22  formed in the plate  10  is inserted between the bottom surface  31  a of the upper jaw  31  and the upper surface  32   a  of the lower jaw  32  of the guide. 
         [0039]    Then, the upper jaw  31  of the connected guide  30  passes the upper surface of the channel groove  22  and protrudes toward the center of the insertion holes  20 , and the bottom surface  31   a  of the protruded upper jaw  31  contacts an upper surface of the head  101  of the screw  100  that is entering into the insertion hole  20 , thereby locking the screw  100  and providing a hooking operation to the screw  100  not to retreat. 
         [0040]    As shown in  FIG. 4 , the engaged guide  30  can rotate right/leftward until the upper jaw  31  and the lower jaw  32  are hooked over the stepped surfaces  23  at both sides of the channel groove  22 . 
         [0041]    Additionally, a tension part  40  for pushing the guide  30  toward the center of the plate  10  is formed inside the extension groove  50 . 
         [0042]    As shown in  FIGS. 2 to 3 , the tension part  40  includes: a base  41  extending toward the center of the plate  10  at one side of an edge of the extension groove  50 ; a first curved part  42  that is bent towards the guide  30  at the end of the base  41 ; and a second curved part  43  that is bent in parallel with the connective surface  33  of the guide  30  at the end of the first curved part  42  wherein the contact surface between the second curved part  43  and the connective surface of the guide  30  forms an arm  45 . 
         [0043]    At this time, another tension part  40  may be formed additionally for an another insertion hole  20  from the end of the base  41  of the tension part  40  wherein a branching part  44  is formed at the point where the another tension part starts to be formed. 
         [0044]    The arm  45  of the tension part  40  will have a self-tension force for pushing the guide  30  to be in contact with the arm  45 , since the elasticity from the bending shapes of the first curved part  42  and the second curved part  43  is applied to the arm  45 . 
         [0045]    Accordingly, as shown in  FIG. 5 , the guide  30  can be pushed backwards in the direction of the center of the plate  10  or be returned to the direction of the center of the insertion holes  20 , with the tension force of the arm  45 . 
         [0046]    Hereinafter, the operation of an apparatus for fixing a cervical spine having a self tension part of the first exemplary embodiment of the present invention will be described in detail.  FIGS. 6 to 7  are views showing an operating condition of an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention. 
         [0047]    First, as shown in the left drawing of  FIG. 6 , a screw  100  provided with a head  101  at the upper part and a screw body  102  at the lower part for fixing the plate  10  of an apparatus for fixing a cervical spine according to the first exemplary embodiment of the present invention, enters into the insertion holes  20  of the plate  10 , and then, the guide  30  with an elastic force provided from the arm  45  of the tension part  40  is pushed backward toward the center of the plate  10  by the side surface  101   a  of the entering head  101  while the guide  30  contacts the head  101  of the screw  100  that enters downward. This state refers to an “Unlock” condition wherein the plate is not yet fixed with the screw  100 . 
         [0048]    However, when the screw  100  enters further into the insertion holes  20 , the head  101  drops along a slope of the upper jaw  31  and then intrudes into a space between the upper jaw  31  and the lower jaw  32 . At this time, the head is protruded frontward with the tension force of the arm  45  that has been pushed rearward to push the guide  30  toward the center of the insertion hole  20  while the contact between the head  101  of the screw  100  and the guide  30  is released. 
         [0049]    Then, as shown in the right drawing of  FIG. 6 , the bottom surface  31  a of the upper jaw  31  that passes through the upper surface of the channel  22  and is protruded toward the center of the insertion holes  20 , comes in contact with the upper surface of the head  101  of the screw  100 , and the upper surface of the head  101  of the screw  100  is hooked over the bottom surface  31   a  of the upper jaw  31 , thereby placing the screw  100  in “locking” state. 
         [0050]    Under such a locking state of the screw  100 , a phenomenon of screw retreatment of the apparatus for fixing a cervical spine can be prevented since the head  101  of the screw  100  is hooked over the upper jaw  31  of the guide  30 . 
         [0051]      FIG. 7  is a partial sectional view showing an apparatus for fixing a cervical spine according to a first exemplary embodiment of the present invention under such a locking condition, taken along a part of an inner wall  21  of an insertion hole  20 . 
         [0052]    As shown in the left drawing of  FIG. 7 , it is a matter of course that in the apparatus for fixing a cervical spine according to an embodiment of the present invention the screw  100  may enter into vertically the plate  10  to be locked, and further, as shown in the right drawing of  FIG. 7 , in the apparatus for fixing a cervical spine according to an embodiment of the present invention, when the screw  100  enters into the place  10  with a predetermined deviation angle (a) rather than a vertical direction, the guide  30  will rotate right/leftward in the engaged channel groove  22  along the deviation angle (a) of the head  101  of the screw  100  that enters therein, and the head  101  of the screw  100  will be hooked over the upper jaw  31  of the rotated guide  30 . 
         [0053]    Accordingly, according to the present invention, problems which may be caused by the conventional screw that is inserted at various angles during the operation of the screw for fixing a cervical spine can be solved at once, and moreover, the screw for the apparatus for fixing a cervical spine can be fixed simply and conveniently without paying attention to the entering angle of the screw to be fixed. 
         [0054]    Next, a configuration and operation of the apparatus for fixing a cervical spine of the second exemplary embodiment of the present invention will be described. 
         [0055]    The apparatus for fixing a cervical spine  2  of the second exemplary embodiment of the present invention is provided with the guide  30  and the tension part  40 , which are modified from those in the first exemplary embodiment of the present invention, and hereinafter, the configuration and operation of the apparatus for fixing a cervical spine will be described in detail referring to  FIGS. 8  toll. 
         [0056]      FIG. 8  is a perspective view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention,  FIG. 9  is a plan view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention,  FIG. 10  is a bottom view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention,  FIG. 11  is an exploded perspective view showing an apparatus for fixing a cervical spine according to a second exemplary embodiment of the present invention, and  FIG. 12  is a sectional view taken along line A-A of  FIG. 9 . 
         [0057]    Referring to  FIGS. 8 to 10 , the apparatus for fixing a cervical spine  2  according to the second exemplary embodiment of the present invention is provided with a plate  110  of a flat shape, and the plate  110  may be made preferably of a rigid metal such as titanium, etc., similarly to the first exemplary embodiment of the present invention. 
         [0058]    The plate  110  is shaped as a quadrangle, and each edge thereof is curved. 
         [0059]    Further, inside of each edge of the plate  110 , one or more insertion holes  120  into which screws  100  for fixing the plate  110  to the cervical spine are inserted are perforated through the plate  110  and similar to the first exemplary embodiment of the present invention, two, six, eight or more insertion holes may be provided depending on the fixation level of a cervical spine fixing operation. 
         [0060]    Further, an inner wall  121  of the insertion hole  120  is curved to be meshed with the shape of a head  101  of a screw  100 . 
         [0061]    Additionally, an extension groove  150  is provided through the plate  110  between the insertion hole  120  and a through-hole  111  formed at the center of the plate  110 , and a channel groove  122  is formed at the boundary of the insertion holes  120  and the extension groove  150 , with stepped surfaces  123  each having a predetermined height from the surface of the plate  110  at both sides. 
         [0062]    A guide  130  for locking the screw  100  that is inserted into the insertion holes  120  is inserted into the channel groove  122 . 
         [0063]    As shown in the exploded perspective view of  FIG. 11 , the guide  130  is formed integrally by connecting an upper jaw  131  and a lower jaw  132  in flat shapes, which are extended horizontally, with a connective surface  133  that is extended vertically. 
         [0064]    Further, the tension part  140  with tension force in a plate or a rod shape is attached to the inside of the connective surface  133  of the guide  130  at one side and the connective surface  133 ′ of the guide  130 ′ at the other side to form a pair of two guides  130  as configured above. 
         [0065]    At this time, as shown in  FIG. 12 , the tension part  140  is inserted into the insertion groove  112  formed at the lower part of the channel groove  122 , and under this condition, the guides  130  and  130 ′ are connected to the channel groove  122 , respectively such that the channel groove  122  is inserted between the bottom surface  131   a  of the upper jaw  131  and the upper surface  132   a  of the lower jaw  132  of the respective guides  130  and  130 ′. 
         [0066]    Then, the upper jaw  131  of the connected guide  130  passes through the upper surface of the channel groove  122  and is protruded toward the center of the insertion holes  120 , and the bottom surface  131   a  of the protruded upper jaw  131  contacts an upper surface of the head  101  of the screw  100  that is entering into the insertion hole  120 , thereby locking the screw  100  and providing a hooking operation to the screw  100  not to retreat. 
         [0067]    As shown in  FIG. 12 , the engaged guide  130  can rotate right/leftward until the upper jaw  131  and the lower jaw  132  are hooked over the stepped surfaces  123  at both sides of the channel groove  122 , respectively. 
         [0068]    The tension part  140  that is attached to the guide  130  has a self-tension force for pushing the guide  130  toward the center of the plate  110 . 
         [0069]    Accordingly, as shown in  FIG. 13 , the guide  130  rotates such that the guide is pushed toward the center of the plate  110  with the tension force of the tension part  140 , and returns again toward the center of the insertion holes  120  with the tension force of the tension part  140 . 
         [0070]    Meanwhile, the number  134 , which is not described, refers to a hole formed through the upper jaw  131  of the guide  130 . 
         [0071]    The apparatus for fixing a cervical spine  2  having a self tension part according to the second exemplary embodiment of the present invention performs same operation as the apparatus for fixing a cervical spine  1  according to the first exemplary embodiment of the present invention; the operation of the apparatus for fixing a cervical spine  2  according to the second exemplary embodiment of the present invention will be described referring to an operating condition of the screw being inserted in  FIG. 14 . 
         [0072]    First, as shown in the upper drawing of  FIG. 14 , the screw  100  for fixing the plate  110  according to the second exemplary embodiment of the present invention enters into the insertion holes  120  wherein the screw  100  includes a head  101  at the upper part and a screw body  102  at the lower part. 
         [0073]    Then, the guide  130  that is given with a resilience from the arm  45  of the tension part  40  is pushed backward toward the center of the plate  100  by the side surface  101   a  of the head  101  while the guide  130  contacts the head  101  of the screw  100  that enters downward. This condition refers to an “Unlock” state wherein the plate is not yet fixed with the screw  100 . 
         [0074]    However, when the screw  100  enters further into the insertion holes  120 , the head  101  drops along a slope of the upper jaw  131  of the guide  130  and then intrudes into a space between the upper jaw  131  and the lower jaw  132 . 
         [0075]    At this time, the contact between the head  101  of the screw  100  that intrudes into a space between the upper jaw  131  and the low jaw  132  and the guide  130  is released and the guide  130  returns again toward the center of the insertion holes  120  with the tension force of the tension part  140  that has been pushed backward. 
         [0076]    Then, as shown in the lower drawing of  FIG. 14 , the bottom surface  131   a  of the upper jaw  131  that passes through the upper surface of the channel  122  and is protruded toward the center of the insertion holes  120  comes in contact with the upper surface of the head  101  of the screw  100 , and the upper surface of the head  101  of the screw  100  is hooked over the bottom surface  131   a  of the upper jaw  131  under this condition, thereby placing the screw  100  in a “locking” state. 
         [0077]    Under such a locking condition of the screw  100 , a phenomenon of screw retreatment of the apparatus for fixing a cervical spine can be prevented since the head  101  of the screw  100  is hooked over the upper jaw  131  of the guide  130 . 
         [0078]    Meanwhile, according to the apparatus for fixing a cervical spine  2  of the second exemplary embodiment as operated above, even when the screw  100  enters into the plate, with a predetermined deviation angle (a) rather than a vertical direction, the guide  130  can rotate right/leftward in the engaged channel groove  122  along the deviation angle (a) of the head  101  of the screw  100  that enters, and thus the screw for the apparatus for fixing a cervical spine can be fixed simply and conveniently without paying attention to the entering angle of the screw to be fixed at an operation by using the apparatus for fixing a cervical spine  1  according to the first exemplary embodiment of the present invention. 
         [0079]    According to the apparatus for fixing a cervical spine of the present invention, the guide that rotates at a predetermined angle inside the insertion hole of the screw is fixed in close contact along the head of the screw that is entering at various angles, thereby fixing a screw firmly regardless of entering angle of the screw. 
         [0080]    Additionally, according to the apparatus for fixing a cervical spine of the present invention, the operator can execute the operation by using the apparatus for fixing a cervical spine much simply and easily without paying attention to the entering angle of the screw to be fixed, thereby reducing the time for the operation. 
         [0081]    While an apparatus for fixing a cervical spine of the present invention is described in detail referring to the accompanying drawings, however, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.