Abstract:
A spinal fusion surgery instrument for implanting and an intervertebral cage thereof are provided. The spinal fusion surgery instrument includes a body, a gripper subassembly, a first control subassembly, and a second control subassembly. The first control subassembly is provided to generate a displacement between a first connecting member and a second connecting member of the gripper subassembly to change the angle of gripper of the intervertebral cage. The second control subassembly is provided to enable a first gripper member and a second gripper member of the gripper subassembly separating smoothly from the dowel pins of the intervertebral cage. By means of the operation model, the spinal fusion surgery instrument may be controlled easily, and the orientation of the intervertebral cage may be promoted in the process of the surgery.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Taiwan Patent Application No. 104113539, filed on Apr. 28, 2015, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to an implant instrument and an intervertebral cage thereof, in particular to the implant instrument and the intervertebral cage thereof which are feasible to be applied to the transforaminal lumbar interbody fusion (TLIF). 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, the vertebrae disease is caused by long-term inappropriate pose, sport injury or comes with ages. When the intervertebral disk is damaged severely, two adjacent spine bones may approach with each other abnormally to suppress the surrounding nerves and the pain caused by the nerve compression may disable the patient from exercising. 
         [0006]    Currently, the most common treatment is to implant an intervertebral cage into a location between two adjacent spine bones by means of an implant instrument, so as to increase or recover the distance between the two adjacent spine bones and avoid the nerves from being suppressed. In the case of the treatment, the clinical surgeon operates the discectomy and then implants the intervertebral cage into a location between two adjacent spine bones to recover the stability of the vertebrae. The TLIF generally has three manners of anterior, posterior and transforaminal lumbar, and the used intervertebral cage may vary with the manners. In practice, the transforaminal lumbar has advantages of less negative effect upon the surrounding tissues of the patient and shorter postoperative healing time, compared with the other surgery. However, as far as the surgeon is concerned, the transforaminal lumbar has a smaller operative field and a higher demand in terms of operating the surgical instruments. When the implant instrument and the intervertebral cage are implanted into the human body, the surgeon can only operate the surgical instruments according the instinct, touch and experience as it is difficult to do through visual contact. In addition, when the surgeon plans to separate the implant instrument from the intervertebral cage, even the intervertebral cage is placed in the accurate position, the intervertebral cage is easy to deviate from its accurate position due to the motion of the implant instrument, such that the repositioning is necessary and the surgery time has to be extended. 
         [0007]    As a result, the inventor of the present invention provides a spinal fusion surgery instrument for implanting and an intervertebral cage thereof which aim to improve the shortcomings of the current technique, so as to promote the clinical or medical practicability. 
       SUMMARY OF THE INVENTION 
       [0008]    In view of the aforementioned problem, a primary objective of the present invention provides a spinal fusion surgery instrument for implanting and an intervertebral cage thereof which change an angle with respect to the location of the intervertebral cage by adjusting the relative position between each member of the gripper subassembly, so that the complicated operation of the implant instrument is simplified to reduce the arrangement time of the intervertebral cage. 
         [0009]    In view of the aforementioned problem, a primary objective of the present invention provides a spinal fusion surgery instrument for implanting to reduce the expected factors such as elastic fatigue, delayed movement and so on of the elastic member or the flexible member by adjusting the relative movement between the stiffener members, such that the uncertainty in the operational process can be avoided. In addition, the first fastening slot and the second fastening slot of the jaw portion can separate from the gripping end of the intervertebral cage by enabling the stop pin resists against the guiding shapes of the first gripping member and the second gripping member, such that the technical problems such as vibration, displacement and so on can be resolved when the implant instrument releases the intervertebral cage. 
         [0010]    In view of the aforementioned problem, a primary objective of the present invention provides an intervertebral cage of a spinal fusion surgery, wherein the guiding end of the body thereof is a streamline shape with a sharp angle, which is able to peel off or penetrate the surrounding tissues of the intervertebral disks effortlessly and effectively reduce the residual force formed between the intervertebral disks. The dowel pins disposed in parallel are able to be gripped by the gripper subassembly of the implant instrument, and also applied in the positioning by the C-arm during the process of the surgery, such that the implanted direction and angle of the intervertebral cage of the present invention can be adjusted immediately by the relative position of the dowel pins and the auxiliary dowel pin, so as to shorten the positioning time. 
         [0011]    The present invention provides an implant instrument for gripping and implanting an intervertebral cage into a location between two adjacent spine bones. The intervertebral cage may include a gripping end and a guiding end. The implant instrument may include a body, a gripper subassembly, a first control subassembly, and a second control subassembly. The body may include a grasp rod and a fixed rod. The fixed rod has a first end and a second end, wherein the first end is disposed at the grasp rod, the second end has a shape corresponding to the gripping end of the intervertebral cage. The fixed rod may be disposed with a first guiding slot and a second guiding slot which communicate with the second end. The fixed rod may have a thread outer diameter near a side of the first end and may further include a straight limit slot near a side of the second end. 
         [0012]    The gripper subassembly may include a first connecting member, a first gripping member, a second connecting member and a second gripping member. The first connecting member is connected to the first gripping member and disposed in the first guiding slot, the second connecting member is connected to the second gripping member and disposed in the second guiding slot. The first connecting member has a first thread structure, the second connecting member has a second thread structure, the first gripping member has a first fastening slot, and the second gripping member has a second fastening slot, wherein the first fastening slot and the second fastening slot may form a jaw portion to grip the gripping end of the intervertebral cage. The first control subassembly may include a first rotating shaft and a second rotating shaft, the first rotating shaft may be connected to the second rotating shaft and sleeved outside the fixed rod, an internal thread of the first rotating shaft is screwed to the first thread structure, and an internal thread of the second rotating shaft is screwed to the second thread structure. The second control subassembly may include a sleeve and a gripping rotating shaft, the sleeve is connected to the gripping rotating shaft and sheathed outside the fixed rod. The sleeve may further have a stop pin inserted into the limit slot, and an internal thread of the gripping rotating shaft is screwed to a thread outer diameter of the fixed rod. 
         [0013]    When rotating the first control subassembly, the first connecting member and the second connecting member may respectively be moved to opposite directions along the first guiding slot and the second guiding slot to change a relative position between the jaw portion and the intervertebral cage so as to change an angle with respect to the location of the intervertebral cage. When the second control subassembly is rotated to move the sleeve toward the first end of the fixed rod, the stop pin resists against the first gripping member and the second gripping member for enabling the jaw portion open to release the intervertebral cage; otherwise, when the second control subassembly is rotated to move the sleeve toward the second end of the fixed rod, the jaw portion may be closed. 
         [0014]    Preferably, the first guiding slot and/or the second guiding slot may further include a limit slot near the side of the first end of the fixed rod for limiting the operation of the gripper subassembly. 
         [0015]    Preferably, the implant instrument of the present invention may further include a measuring unit for measuring a depth where the implant instrument inserts into vertebra. The measuring unit is sheathed outside the sleeve. 
         [0016]    Preferably, the first thread structure, the second thread structure, the thread outer diameter or a combination thereof may be a single thread or a multiple thread. 
         [0017]    Preferably, the fixed rod, the first connecting member, the second connecting member or a combination thereof may be integral or assembly-type. 
         [0018]    According to the foregoing objective, the present invention further provides an intervertebral cage being gripped and implanted into a location between two adjacent spine bones by an implant instrument. The intervertebral cage includes a body, dowel pins and at least one auxiliary dowel pin. The body may be a structure including a plurality of penetration cavities which are mutual interlaced. The body may have a guiding end and a gripping end. The gripping end may have two dowel holes in parallel, and the gripping end may be disposed with at least one auxiliary dowel hole. 
         [0019]    Two dowel pins may be respectively inserted into the two dowel holes, and at least one auxiliary dowel pin may be inserted into the corresponding auxiliary dowel hole. The two dowel pins and the at least one auxiliary dowel pin may assist in displaying and guiding a dynamic relative location of the body in the process of the surgery, such that the positioning accuracy of the surgery can be promoted. 
         [0020]    Preferably, the intervertebral cage may be shaped with a guided circumferential angle to avoid damaging surrounding tissues accidentally in the process of the surgery. 
         [0021]    Preferably, the plurality of penetration cavities may remove a volume of the body by 30-70%. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The detailed structure, operating principle and effects of the present invention will now be described in more details hereinafter with reference to the accompanying drawings that show various embodiments of the disclosure as follows. 
           [0023]      FIG. 1  is a schematic diagram of the spinal fusion surgery instrument for implanting and the intervertebral cage thereof of the present invention. 
           [0024]      FIG. 2  is an explosion diagram for showing the spinal fusion surgery instrument for implanting of the present invention. 
           [0025]      FIG. 3  is a schematic diagram of the intervertebral cage of the present invention. 
           [0026]      FIG. 4  is a schematic diagram for showing the placement operations of the intervertebral cage of the present invention. 
           [0027]      FIG. 5  is a schematic diagram for showing the relief operations of the intervertebral cage of the present invention. 
           [0028]      FIG. 6  is a schematic diagram for showing the Transforaminal Lumbar Interbody Fusion by means of the spinal fusion surgery instrument for implanting and the intervertebral cage thereof of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can realize the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. 
         [0030]    The exemplary embodiments of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure, which, however, should not be taken to limit the disclosure to the specific embodiments, but are for explanation and understanding only. 
         [0031]    Please refer to  FIG. 1 ,  FIG. 2 , and  FIG. 3 . As shown in the FIGS., an implant instrument  100 , which may be a spinal fusion surgery instrument for implanting, of the present invention is applied to grip and implant an intervertebral cage  200  to a location between two adjacent spine bones. The intervertebral cage  200  has a guiding end  211  and a gripping end  212 . The implant instrument  100  includes a body  100 , a gripper subassembly  120 , a first control subassembly  130 , a second control subassembly  140  and a measuring unit  150 . The measuring unit  150  is sheathed outside the sleeve  141  of the second control subassembly  140 . The body  110  includes a gasp rod  111  and a fixed rod  112 . The gripper subassembly  120  includes a first connecting member  121 , a first gripping member  122 , a second connecting member  123  and a second gripping member  124 . The first control subassembly  130  includes a first rotating shaft  131  and a second rotating shaft  132 . The second control subassembly  140  includes the sleeve  141  and a gripping rotating shaft  142 . The fixed rod  112  has a first end  1121  and a second end  1122 . The first end  1121  may be assembled on the grasp rod  111  by means of screwing, sleeving, and so on. The second end  1122  has a shape corresponding to the gripping end  212 . The fixed  112  has a thread outer diameter  1125  near a side of the first end  1121 . 
         [0032]    More precisely, a length of the fixed rod  112  is designed according to the necessary operative field and the operating space based on the injured area. When the required length of the fixed rod  112  is short, the fixed rod  112  may be formed integrally. The fixed rod  112  with the shorter length has a better precise operation, but the operative field may be shielded by the surgical instruments. For the sake of achieving a better operative field the fixed rod  112  is designed with a longer length as such with an assembly-type fixed rod  112  may be operated. The diagrams of the present invention apply an assembly-type fixed rod  112  as an exemplary embodiment. In addition to the better operative field, the assembly-type fixed rod  112  is easy to be treated and assembled. The dual structure of the fixed rod  112  may be assembled from the two sides of the sleeve  141  respectively, and then a pin is used to fix the dual structure of the fixed rod  112  as integrity. In practice, the first connecting member  121  and the second connecting member  123  may be integral or assembly-type according to the actual requirements. 
         [0033]    The fixed rod  112  is disposed with a first guiding slot  1123  and a second guiding slot  1244  which communicate with the second end  1122 . In practice, the first guiding slot  1123  and the second guiding slot  1124  are respectively disposed at an upper side and a lower side of the fixed rod  112  in parallel, so that the fixed rod  112  is shaped as a H-shaped longer shaft as a whole. Moreover, the first guiding slot  1123  and the second guiding slot  1124  respectively include limit slots  1127 ,  1128  near the first end  1121 . The first connecting member  121  is connected to the first gripping member  122  and disposed in the first guiding slot  1123  to move linearly along the first guiding slot  1123 . Similarly, the second connecting member  123  is connected to the second gripping member  124  and disposed in the second guiding slot  1124  to move linearly along the second guiding slot  1124 . In practice, the lengths of the limit slots  1127 ,  1128  may be applied to respectively limit the range of motion of the first connecting member  121  and the second connecting member  123 . 
         [0034]    Please refer to  FIG. 1  and  FIG. 4  together. As shown in the FIGS., the first rotating shaft  131  of the first control subassembly  130  is connected to the second rotating shaft  132  to rotate simultaneously. The first control subassembly  130  is sleeved outside the fixed rod  112  for being used by a surgeon. An internal thread of the first rotating shaft  131  is screwed to the first thread structure  1215  disposed at one end of the first connecting member  121 , and an internal thread of the second rotating shaft  132  is also screwed to a second thread structure  1235  of the second connecting member  123 . When the surgeon rotates the first control subassembly  130 , the first connecting member  121  and the second connecting member  123  respectively are moved to opposite directions along the first guiding slot  1123  and the second guiding slot  1124  of the fixed rod  112 . In practice, the first thread structure  1215 , the second thread structure  1235 , the thread outer diameter  1125  of the fixed rod  112  or a combination thereof may be a single thread characterized of accurate motion or a multiple thread which is applied to increase the operating space and shorten the rotation time. 
         [0035]    To be precise, the first gripping member  122  of the gripper subassembly  120  has a first fastening slot  1225 , and the second gripping member  124  of the gripper subassembly  120  has a second fastening slot  1245 . The first fastening slot  1225  and the second fastening slot  1245  are applied to form a jaw portion  128  to grip the gripping end  212  of the intervertebral cage  200 . In practice, the first fastening slot  1225  and the second fastening slot  1245  are disposed in parallel to grip a dowel pin  220  of the intervertebral cage  200 . For example, when rotating the first control subassembly  130 , the first connecting member  121  may move to the second end  1122  along the first guiding slot  1123  and the second connecting member  123  may move to the first end  1121  along the second guiding slot  1124 . The dislocation generated between the first connecting member  121  and the second connecting member  123  changes an angle with respect to the location of the intervertebral cage  200 . 
         [0036]    Please refer to  FIG. 1  and  FIG. 5  together. The sleeve  141  of the second control subassembly  140  is connected to the gripping rotating shaft  142  and sheathed outside the fixed rod  112 . An internal thread of the gripping rotating shaft  142  is screwed to a thread outer diameter  1125  of the fixed rod  112 . When the surgeon rotates the second control subassembly  140 , the sleeve  141  moves linearly toward the first end  1121  or the second end  1122  along the fixed rod  112  according to the rotation direction, so as to close or open the jaw portion  128 . Furthermore, the fixed rod  112  further includes a straight limit slot  1126  near a side of the second end  1122 , and the sleeve  141  further includes a stop pin  1415 , and the stop pin is inserted into the straight limit slot  1126 . When rotating the second control subassembly  140  to enable the sleeve  141  to move toward the first end  1121  of the fixed rod  112 , the stop pin  1415  resists against, the guiding shapes of the first gripping member  122  and the second gripping member  124 , such that the first fastening slot  1225  and the second fastening slot  1245  of the jaw portion  128  are able to separate from the dowel pin  220  of the gripping end  212  smoothly. As a result, technical problems, such as vibration, displacement and so on, during the releasing the intervertebral cage by using the current instrument is able to be resolved. In practice, the ends of the first gripping member  122  and the second gripping member  124  may be designed as the corresponding guiding shapes according to the actual requirements. 
         [0037]    Please refer to  FIG. 1  and  FIG. 3  together. The present invention further provides an intervertebral cage  200  which includes a body  210 , two dowel pins  220 , and an auxiliary dowel pin  230 . The body  210  has a structure comprising a plurality of penetration cavities  215  which are mutual interlaced, and upper and lower surfaces of the body  210  may be disposed with uneven surface to increase the contact area between the two spine bones and the intervertebral cage  200 , such that the displacement or separation of the intervertebral cage  200  caused by external force may be avoided after the intervertebral cage  200  is implanted. In practice, the penetration holes formed by the penetration cavities  215  enable the bone cells, nerves, blood vessels and so on of the patient penetrating or adhering between the bone cells, nerves, blood vessels and so on of the patient so as to promote the efficiency of the healing. However, when a removal ratio of the volume of the body  210  by the penetration cavities  215  is too high, the entire strength of the intervertebral cage  200  may be affected and the structure thereof may even be damaged. When the removal ratio is too small, the degree of the self-healing of the patient&#39;s cells may be affected. As a result, the plurality of penetration cavities  215  remove a volume of the body  210  by 30-70%, and preferably, by 35-65%. 
         [0038]    The body  210  may be a bent formation such as peas or a meniscus, or a bullet shape. The body  210  includes a guiding end  211  and a gripping end  212 . The guiding end  211  is a streamline shape with a sharp angle, which is able to peel off or penetrate the surrounding tissues of the intervertebral disks effortlessly and effectively reduce the residual force formed between the intervertebral disks. In practice, the body  210  is shaped with a guided circumferential angle to avoid damaging surrounding tissues such as nerves, blood vessels and so on accidentally in the process of the surgery. The gripping end  212  of the body  210  is disposed with two dowel holes  2125  in parallel and the guiding end  211  is disposed with at least one auxiliary dowel hole  2115 . The two dowel pins  220  and the auxiliary dowel pin  230  are penetrated in the corresponding holes arranged on the body  210 . The two dowel pins  220  disposed in parallel is not only able to be gripped by the gripper subassembly  120  of the implant instrument  100 , but also applied in the positioning by the C-arm in the process of the surgery. The intervertebral cage  200  of the present invention applies a relative position between the two dowel pins  220  and the auxiliary dowel pin  230  to promptly correct the direction and angle which the intervertebral cage  200  are implanted to, so as to shorten the positioning time. In practice, using various numbers and diameters of the dowel pins  220  and the auxiliary dowel pin  230  may facilitate the surgeon to see a dynamic position of the implant instrument  100  and the intervertebral cage  200  clearly in the process of the surgery, so as to enhance the positioning accuracy in the process of the surgery. 
         [0039]    Please refer to  FIG. 4 ,  FIG. 5 , and  FIG. 6  together. When the implant instrument  100  grips and implants the intervertebral cage  200  to the mounting position of the intervertebral foramen B, the surgeon implants the implant instrument  100  into the human body slowly. When the intervertebral cage  200  contacts the surface of the spine bone, the surgeon releases and moves the measuring unit  150  to the scale  0  and then re-blocks and re-fixes on the sleeve  141  to complete the step of positioning calibration. When the surgeon keeps pushing the intervertebral cage  200 , the scales of the measuring unit  150  displays a depth where the implant instrument  100  and the intervertebral cage  200  insert into vertebra. 
         [0040]    When the intervertebral cage  200  is confirmed to be located in the mounting position through the display device (not shown) and the measuring unit  150  or by the double checking of the display device and the measuring unit  150 , the surgeon holds the measuring unit  150  in one hand and the other hand rotates the first control subassembly  130  to hereby change the gripping positions between the implant instrument  100  and the intervertebral cage  200  to rotate the intervertebral cage  200  for fitting the intervertebral cage  200  into an optimal mounting position. Moreover, when the intervertebral cage  200  is located in the mounting position, the surgeon operates the second control subassembly  140  to separate the intervertebral cage  200  from the implant instrument  100  smoothly. 
         [0041]    The implant instrument of the present invention is able to adjust an angle with respect to the location of the intervertebral cage by adjusting the relative positions between each member of the gripper subassembly such that the surgeon can operate instinctively in the process of the surgery. Moreover, the implant instrument of the present invention releases the intervertebral cage  200  smoothly to reduce the positioning error. The intervertebral cage of the present invention further applies a relative position between the two dowel pins and the auxiliary dowel pin to promptly correct the direction and angle whereto the intervertebral cage is implanted, so as to shorten the positioning time. 
         [0042]    Furthermore, when the actuating member of the existing device is an elastic member or a flexible member, the implant instrument of the present invention is able to reduce the expected factors such as elastic fatigue, delayed movement and so on by adjusting the relative movement between the stiffener members, such that the uncertainty in the operational process can be avoided. 
         [0043]    While the means of specific embodiments in present invention has been described by reference drawings, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the disclosure set forth in the claims. The modifications and variations should in a range limited by the specification of the present invention.