Abstract:
Disclosed is a spine fixation apparatus, more particularly, a pedicle screw implanted into a spine and an operating device for the pedicle screw capable of easily inserting a rod to a head  5  section of the pedicle screw in order to securely fix the spine. The pedicle screw has a head section including a recess part defined by first and second sidewalls, a screw section, and a support unit formed at an upper portion of the recess part of the head section while connecting the first sidewall to the second sidewall.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a division of U.S. patent application Ser. No. 10/954,227, which was filed on Oct. 1, 2004, the entire subject matter of which is incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a spine fixation apparatus, and more particularly to a pedicle screw implanted into a spine and an operating device for the pedicle screw capable of easily inserting a rod to a head section of the pedicle screw in order to securely fix the spine. 
     2. Description of the Prior Art 
     As generally known in the art a spine fixation apparatus is provided for treating patients who have vertebral disease caused by traffic accidents or fall accidents. For instance, the spine fixation apparatus connects bones forming the spine to each other so as to assist patients with vertebral fracture to be restored to health. 
     A patient makes a living with a spine fixation apparatus implanted into the spine of the patient. Thus, a subsidiary implanted into a body of the patient must have a simple structure and must not be deformed or released even if the patient takes an active life for a long period of time. 
       FIG. 1  shows a conventional spine fixation apparatus. Referring to  FIG. 1 , the conventional spine fixation apparatus includes a pedicle screw  100  provided with a rod  104  and a coupling screw  102  which are coupled to an upper portion of the pedicle screw  100 . 
     The pedicle screw  100  is provided at an upper end thereof with a head section  110  and a lower end thereof with a screw section  120 . The rod  104  is inserted into a recess  114  of the head section  110 . The recess  114  is defined by first and second sidewalls  111  and  112  and receives the rod  104  therein. 
     When the rod  104  has been received in the head section  110  of the pedicle screw  100 , the coupling screw  102  is screw-coupled into the upper portion of the pedicle screw  100  so as to prevent the rod  104  from being separated from the pedicle screw  100 . The first and second sidewalls  111  and  112  of the head section  110  are formed at inner portions thereof with screw sections such that the coupling screw  102  is securely fixed to the head section  110  of the pedicle screw  100 . 
     The screw section  120  of the pedicle screw  100  is screw-coupled into a bone of a spine of a patient so that the pedicle screw  100  is implanted into a body of the patient. The pedicle screw  100  is connected to the other pedicle screw, which is screw-coupled with the other bone of the spine of the patient, through the rod  104 . 
     The rod  104  is inserted into the pedicle screw  100  from an upper portion of the pedicle screw  100  when the pedicle screw  100  is implanted into the patient. Accordingly, it is necessary to make elongated incisions in the patient&#39;s back. That is, the back of the patient must be incised corresponding to a length of the rod  104 . Reference numeral  116  represents an inner bottom surface of the head section  110 . 
     The current tendency of a surgical operation is to minimize an incision part in a human body. Thus, there has been suggested a method capable of minimizing an incision part in the back of a patient when a pedicle screw is implanted into the body of the patient. According to the above method, a rod is inserted into the pedicle screw from a lateral portion of the pedicle screw instead of inserting the rod from an upper portion of the pedicle screw. In this case, two pedicle screws can be implanted into the body of the patient without incising the back of the patient in a long size by forming only three incisions (two is for pedicle screws and one is for the rod) in the back of the patient. 
     When the rod is inserted into the pedicle screw from the lateral portion of the pedicle screw, one end of the rod must be easily inserted into a recess part of the pedicle screw. In addition, it is necessary to prevent the rod from being easily separated from the recess part. The rod is inserted into the recess part of a head section of the pedicle screw and fixedly coupled thereto by means of a coupling screw. Accordingly, the rod can be easily separated from the head section of the pedicle screw before the coupling screw is coupled thereto. 
     For this reason, if the conventional pedicle screw is used for the minimum incision surgery, the pedicle screw may be separated from the pedicle screw while the surgery operation is being carried out, resulting a delay or a failure of the surgery operation. 
     In addition, since the minimum incision surgery is carried out while making several incisions in the back of the patient while keeping the size of the incisions quite small, a position of the pedicle screw is not exposed to an exterior. Thus, it is difficult to determine a coupling position of a screw section of the pedicle screw having a diameter of about 5 mm with respect to the spine of the patient. 
     In the meantime, the minimum incision surgery requires great skill when determining the coupling position of the pedicle screw with regard to the spine of the patient and inserting the rod into the pedicle screw from the lateral portion of the pedicle screw. This is because the incisions made in the back of the patient tend to be clogged by skin and the operator cannot see the pedicle screw, which has already been implanted in the body of the patient. Thus, the operator must perform the surgical operation while gripping the pedicle screw with one hand in order to couple the pedicle screw to a precise position of the spine of the patient. 
     That is, since the minimum incision surgery is carried out while making several incisions in the back of the patient and keeping the size of the incisions quite small the location of the pedicle screw is “subcutaneous”, so that the operator cannot easily carry out minimum incision surgery. 
     Therefore, it is necessary to provide an apparatus to facilitate minimum incision surgery capable of allowing the operator to easily couple a pedicle screw to the spine of the patient and insert a rod into the pedicle screw from a lateral portion of the pedicle screw. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art and an object of the present invention is to provide a pedicle screw including a support unit which connects a first sidewall of a head section to a second sidewall of the head section in order to prevent a rod, which is inserted into the head section of the pedicle screw from a lateral portion of the pedicle screw, from being separated upward from the head section. 
     Another object of the present invention is to provide a pedicle screw including an indicator protruding from an end of a screw section of the pedicle screw for precisely indicating an insertion point of the pedicle screw during minimum incision surgery. 
     Still another object of the present invention is to provide an operating device for a pedicle screw allowing an operator to easily perform minimum incision surgery while making several incisions for the pedicle screw and a rod in the back of a patient. 
     To accomplish the above objects, according to one aspect of the present invention, there is provided a pedicle screw comprising: a head section including a recess part defined by first and second sidewalls; a screw section; and a support unit formed at an upper portion of the recess part of the head section while connecting the first sidewall to the second sidewall. 
     According to the preferred embodiment of the present invention, the pedicle screw has a guide hole extending from an inner bottom surface of the head section to a lower end portion of the screw section. 
     To accomplish the above objects, according to another aspect of the present invention, there is provided an operating device for a pedicle screw, the operating device comprising: a screw coupling rod having an elongated pipe shape; a body having a first side coupled to the screw coupling rod; a rotating member having a first end coupled to a second side of the body in such a manner that a second end of the rotating member rotates about the first end thereof, and a rod receiver coupled to the second end of the rotating member. 
     According to the preferred embodiment of the present invention, the body includes a coupling hole into which the first end of the rotating member is inserted and an elongated rod having a coupling slot for coupling the screw coupling rod. 
     The screw coupling rod is coupled to the body by means of a coupling member, the elongated rod extends by passing through the coupling member, and the coupling member is provided with a first screw, which is screw-coupled with the coupling slot, and a second screw for supporting the screw coupling rod. 
     The rod receiver has a curved shape in the form of an arc and the rod is detachably coupled to one end of the rod receiver. The rod receiver is provided at an inner portion thereof with a flexible shaft which is screw-coupled with one end of the rod, and the rod is coupled with or separated from the rod receiver according to a rotational direction of the flexible shaft. 
     The screw coupling rod has an upper end portion coupled to the body and a lower end portion into which a pedicle screw is inserted. The screw coupling rod is formed at a lower end portion thereof with a rod hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view showing a conventional spine fixation apparatus; 
         FIG. 2  is a front view of a pedicle screw according to one embodiment of the present invention; 
         FIG. 3  is a plan view of a pedicle screw according to one embodiment of the present invention; 
         FIG. 4  is a perspective view of a pedicle screw according to one embodiment of the present invention; 
         FIG. 5  is a perspective view showing usage of a pedicle screw according to one embodiment of the present invention; 
         FIG. 6  is a perspective view showing usage of a pedicle screw according to one embodiment of the present invention; 
         FIG. 7  is a perspective view showing an operating device for a pedicle screw according to one embodiment of the present invention; 
         FIG. 8  is a front view showing an operating device for a pedicle screw according to one embodiment of the present invention; 
         FIG. 9  is a plan view showing an operating device for a pedicle screw according to one embodiment of the present invention; 
         FIG. 10  is a perspective view showing an operational state of an operating device for a pedicle screw according to one embodiment of the present invention; 
         FIG. 11  is an enlarged sectional view showing a rod inserted into a rod receiver according to one embodiment of the present invention; and 
         FIG. 12  is an enlarged sectional view showing a rod being separated from a rod receiver according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. 
       FIGS. 2 to 4  are front, plan and perspective views of a pedicle screw according to one embodiment of the present invention Referring to  FIGS. 2 to 4 , the pedicle screw includes a head section  10  formed with first and second sidewalls  11  and  12 . A recess  14  is formed between the first and second sidewalls  11  and  12  and a support unit  18  is formed at an upper portion of the recess  14  in order to connect the first sidewall  11  to the second sidewall  12 . 
     The support unit  18  horizontally connects upper portions of the first and second sidewalls  11  and  12  to each other. Thus, the support unit  18  forms a hole having a predetermined size together with the recess  14 . The shape and position of the support unit  18  may vary so far as the support unit  18  connects the first sidewall  11  to the second sidewall  12  and prevents a rod (not shown) from being separated upwardly of the recess  14 . As shown in  FIG. 3 , the recess  14  is formed with a screw hole  17  such that a coupling screw ( 102 , see  FIG. 6 ) can be screw-coupled with the recess  14  from an upper portion of the support unit  18 . Since the coupling screw  102  is screw-coupled with the screw hole  17  of the recess  14 , the support unit  18  must be aligned such that it does not block a movement path of the coupling screw  102 . 
     A guide hole  19  is formed at a center of an inner bottom surface  17  of the head section  10  formed between the first and second sidewalls  11  and  12  of the head section  10 . The guide hole  19  downwardly extends from the inner bottom surface  17  of the head section  10  to a lower end of a screw section  20  through an inner portion of the screw section  20 . 
       FIG. 5  is a perspective view showing usage of a pedicle screw according to one embodiment of the present invention. Referring to  FIG. 5 , the pedicle screw is located at a precise position of the spine by means of a position indication driver  30 . 
     The position indication driver  30  has a handle  34  and an elongated needle  32  extending downward from the handle  34 . The elongated needle  32  is inserted into the guide hole  19  by passing through the screw hole  17  of the recess  14 . 
     The elongated needle  32  downwardly protrudes beyond a lower end of the screw section  20  of the pedicle screw and makes contact with the spine. When the elongated needle  32  is moved into a precise position of the spine by moving the position indication driver  30 , the pedicle screw is also located in the precise position of the spine. In this state, the pedicle screw is inserted into the spine by rotating the pedicle screw. After that, the position indication driver  30  is separated from the pedicle screw by upwardly pulling the position indication driver  30 . 
     Thus, it is not necessary for the operator to move the pedicle screw while enlarging an incision part in order to find a coupling position of the pedicle screw with regard the spine because the elongated needle  32  can point the coupling position of the pedicle screw. The pedicle screw is rotatably inserted into the spine by means of a separate driver (not shown). 
       FIG. 6  is a perspective view showing usage of a pedicle screw  1  according to one embodiment of the present invention. Referring to  FIG. 6 , the rod  104  is inserted into the pedicle screw  1  from a lateral portion of the pedicle screw  1 . In this case, the rod  104  is prevented from being separated upwardly from the pedicle screw  1  due to the support unit even if the operator does not conduct any additional procedures. 
     When the rod  104  has been inserted into the recess  14  from the lateral portion of the recess  14 , the coupling screw  102  is screw-coupled into the screw hole  17  while pressing the rod  104  downward. Since the rod  104  is prevented from upwardly moving from the recess  14 , it is necessary to push the rod  104  in the lateral di on when removing the rod  104  from the recess  14 . 
     In short due to the support unit  18 , the rod  104  inserted into the recess  14  is prevented from being separated from the recess  104  even if the coupling screw  102  has not been screw-coupled with the recess  14 , so the operator can easily perform the surgical operation. 
     Although it is described that the head section of the pedicle screw is integrally formed with the screw section, the present invention can be applicable for a multi-axial pedicle screw in which a head section is separated from a screw section so that the screw section can move with regard to the head section. 
       FIG. 7  is a perspective view showing an operating device for a pedicle screw according to one embodiment of the present invention,  FIG. 8  is a front view showing the operating device for the pedicle screw, and  FIG. 9  is a plan view showing the operating device for the pedicle screw. Referring to  FIG. 7 to 9 , the operating device for the pedicle screw includes a body  230 , a rotating member  210  rotatably coupled to a rear portion of the body  230 , at least two screw coupling rods  250  vertically coupled to a front portion of the body  230 , and a rod receiver  220  provided at a second end  212  of the rotating member  210  in the form of a curved rod and extends toward a lower end of the screw coupling rods  250 . 
     The rotating member  210  preferably has a reverse “L” shape and a first end of the rotating member  210  is coupled to the rear portion of the body  230  through a rotary screw shaft  214  such that the rotating member  210  can rotate about the rotary screw shaft  214 . The second end  212  of the rotating member  210  is formed with a hole so as to receive the rod receiver  220  therein. As the rotating member  210  rotates, the rod receiver  220  is also moved in up and down directions. 
     An upper end portion of the rod receiver  220  is coupled with the second end  212  of the rotating member  210 . In addition, the rod  104  is detachably coupled with a lower end portion of the rod receiver  220 . The rod receiver  220  has a curved structure in the form of an arc having a predetermined curvature. As the rotating member  210  rotates, the rod receiver  220  also rotates along a predetermined circular route. Preferably, the rod  104  inserted into the lower end portion of the rod receiver  222  has a curved structure with a predetermined curvature identical to the curvature of the rod receiver  220 . Reference numeral  224  represents a fastening screw  224 . 
     The rotating member  210  is connected to the screw coupling rod  250  through the body  230 . Preferably, the body  230  has a “           ”-shaped structure when looking at the body  230  from the upper region of the body  230 . The body  230  is provided at a middle portion thereof with a central protrusion  232  and one end of the rotary screw shaft  214  is inserted into the central protrusion  232  while interposing the first end of the rotating member  210  therebetween. The body  230  includes an elongated rod  234 . The central protrusion  232  is provided at a middle portion of the elongated rod  234 . A coupling slot  236  is longitudinally formed along an upper portion of the coupling screw  234 . At least two screw coupling rods  250  are vertically coupled to the elongated rod  234  in such a manner that the angel of the screw coupling rods  250  can be slightly adjusted.
     The screw coupling rod  250  has a hollow pipe shape and an upper end of the screw coupling rod  250  is coupled to the elongated rod  234 . A pedicle screw (not shown) is inserted into a lower end of the screw coupling rod  250 . The screw coupling rod  250  is formed with a perforated hole  254 . A driver (not shown) may be inserted into the perforated hole  254  of the screw coupling rod  250  in order to manipulate the pedicle screw. Preferably, a rod hole  256  is formed at a lower lateral portion of the screw coupling rod  250 . The rod hole  256  receives a head section of the pedicle screw. That is, as the rotating member  210  rotates, the rod  105  inserted into the second end  222  of the rod receiver  220  is introduced into the head section of the pedicle screw by passing through the rod hole  256 . Coupling members  240  are provided to couple the screw coupling rods  250  to the elongated rod  234  of the body  230 . Each of the coupling members  240  has a hexahedral structure and the elongated rod  234  of the body  234  passes through the coupling member  240 . In addition, a protrusion  258  of the screw coupling rod  250  is inserted into the coupling member  240 . A first screw  242  is screw coupled into the coupling member  240  in order to fix the elongated rod  234  and a second screw  252  is screw coupled into the coupling member  240  in order to fix the protrusion  258  of the coupling rod  250 . 
     The first screw  242  is inserted into the coupling slot  236  of the elongated rod  234 . The first screw  242  extends toward an inner portion of the coupling member  240  by passing through an upper surface of the coupling member  240  so that an end portion of the first screw  242  is inserted into the coupling slot  236  of the elongated rod  234 . When releasing the first screw  242 , the coupling member  240  can move along the elongated rod  234 . In addition, the coupling member  240  can be fixed to predetermined portion of the elongated rod  234  when fastening the first screw  234 . 
     The second screw  252  is screw-coupled into the coupling member  240  in order to adjust a rotational angle or a gradient of the screw coupling rod  250 . The protrusion  258  inserted into the coupling member  240  is provided at an upper end portion of the screw coupling rod  250  and the second screw  252  makes contact with the protrusion  258  of the screw coupling rod  250  by passing through the coupling member  240 . 
     The protrusion  258  has a cylindrical shape and is rotatably inserted into the coupling member  240 . As the protrusion  258  rotates, the screw coupling rod  250  is slightly moved by a predetermined angle. Thus, a position of the screw coupling rod  250  is adjusted in a state that the second screw  252  is slightly released. Then, the second screw  252  is fastened such that the second screw  252  fixedly presses the protrusion  258 , so the position of the screw coupling rod  250  is fixed with respect to the body  230 . 
       FIG. 10  is a perspective view showing an operational state of the operating device for the pedicle screw according to one embodiment of the present invention. Referring to  FIG. 10 , the pedicle screw  1  is inserted into a lower portion of the screw coupling rod  250 . In this state, the rod  104  is inserted into the pedicle screw  1  by rotating the rotating member  210  in the downward direction. 
     That is, the pedicle screw  1  is coupled with the screw coupling rod  250  and the position of the body  230  is determined according to the position of the screw coupling rod  250 . As the rotating member  210  coupled with the body  230  rotates in the downward direction, the rod receiver  220  and the rod  104  connected to the second end  212  of the rotating member  210  may be directed toward the rod hole  256  formed at the lower end portion of the screw coupling rod  250 . 
     Thus, the operator can easily insert the rod  104  into the pedicle screw  1  without performing additional inspection work by simply rotating the rotating member  210  in the downward direction thereof. Therefore, if two incisions for two pedicle screws  1  and one incision for the rod  104  and the rod receiver  220  are made in the back of the patient, the rod  104  can be easily inserted into the pedicle screw  1 . 
     When the rod  104  coupled with a detachment section  222  of the rod receiver  220  has been placed in the head section of the pedicle screw  1  due to the rotation of the rotating member  210 , the coupling screw  102  (see,  FIG. 1 ) is inserted into the perforated hole of the screw coupling rod  250  and the driver is also inserted into the perforated hole of the screw coupling rod  250  in order to fasten the coupling screw  102 , thereby fixedly securing the rod  104  to the pedicle screw  1 . After that, the rod  104  is separated from the rod receiver  220  and the rotating member  210  is rotated in the upward direction, thereby removing the rod receiver  220  from the back of the patient. 
       FIG. 11  is an enlarged sectional view showing the rod inserted into the rod receiver according to one embodiment of the present invention, and  FIG. 12  is an enlarged sectional view showing the rod being separated from the rod receiver according to one embodiment of the present invention. Referring to  FIGS. 11 and 12 , the rod  104  is partially inserted into the detachment section  222  of the rod receiver  220 . The detachment section  222  is formed at a lower end portion of the rod receiver  220  in order to detachably receive the rod  104 . The rod  104  is formed at one end thereof with a female screw section  104   a  such that the rod  104  can be screw-coupled with the rod receiver  220 . The female screw section  104   a  is formed at an inner wall part of a hole formed in the rod  104 . A flexible shaft  226  is positioned in the rod receiver  220 . A male screw section  226   a  of the flexible shaft  226  is located in the vicinity of the detachment section  222  of the rod receiver  220 . The rod  104  has a curved shape in the form of an arc and the female screw section  104   a  formed at one end of the rod  104  is screw-coupled with the male screw section  226   a  of the flexible shaft  226 . 
     The flexible shaft  226  is made from a synthetic resin material, such as plastic, which can be easily bent without deforming a shape thereof. An upper portion of the flexible shaft  226  is connected to a fastening screw  224  provided at an upper end portion of the rod receiver  220 . As the fastening screw  224  rotates, the flexible shaft  226  also rotates. 
     The male screw section  226   a  of the flexible shaft  226  may be coupled with the female screw section  104   a  of the rod  104  or released from the female screw section  104   a  of the rod  104  according to a rotational direction of the fastening screw  224 . If the flexible screw  226  rotates in one direction as shown in  FIG. 8 , the rod  104  is separated from the flexible screw  226 . Accordingly, the rod  104  can be easily implanted into the spine of the patient through the steps of inserting the rod  104  into a target position in the pedicle screw  1 , separating the rod  104  from the flexible screw  226  by rotating the fastening screw  224 , and lifting the rotating member  210 . 
     As described above, the pedicle screw according to the present invention has a support unit capable of preventing a rod from being easily separated from the pedicle screw, thereby facilitating minimum incision surgery. 
     In addition, the pedicle screw according to the present invention is formed with a guide hole, which receives a position indication driver, so the operator can easily detect a precise insertion point of the pedicle screw during minimum incision surgery. 
     In addition, the present invention provides an operating device for the pedicle screw, capable of implanting a plurality pedicle screws into the body of the patient while making several incisions for the pedicle screws and the rod in the back of the patient and keeping the size of incisions quite a small. 
     Furthermore, the operating device for the pedicle according to the present invention may allow an operator to easily insert the rod into the pedicle screw inserted into the incision made in the patient&#39;s back without checking the location of the pedicle screw and the rod with the naked eye. 
     In addition, the operating device for the pedicle according to the present invention can easily separate the rod from the pedicle screw after the rod has been inserted into the pedicle screw. 
     The operating device for the pedicle according to the present invention includes a screw coupling rod, so the number of pedicle screws used for minimum incision surgery may increase without limitation. 
     Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 
     The present disclosure relates to subject matter contained in Korean Patent Application Nos. 10-2002-0056911, filed on Jul. 21, 2004, and 10-2004-0056912, filed on Jul. 21, 2004, the contents of both are herein expressly incorporated by reference in their entireties.