Endplate perforator

Abstract

To provide an end plate perforator that can promote the intervertebral synostosis safely and easily, by forming bone holes being substantially vertical to an end plate.SOLUTION: An end plate perforator 10 includes a needle member 60 movably arranged in an operation case 41 of the end plate perforator, and movably arranged between a buried position buried in the operation case 41 and a protruding position with a tip protruding from an upper sidewall 41a. The end plate perforator 10 also includes a mechanism part 42 arranged in the operation case 41 and connecting between the needle member 60 and an operating rod, and reciprocating the needle member 60 between the buried position and the protruding position by the linear reciprocal movement of the operating rod.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an endplate perforator. [Background technology]

[0002] A common surgical approach to address spinal injuries and pathologies is interbody fusion, which is performed to provide nerve decompression and stabilization in cases of instability in the spine, for example the lumbar spine.

[0003] Interbody fusion procedures typically include anterior interbody fusion, in which the spine is accessed from the front (anterior) of the patient, and posterior interbody fusion, in which the vertebrae are reached through an incision in the patient's back (posterior).

[0004] Anterior interbody fusion is the gold standard in the field and allows for the implantation of the largest cages, but requires a relatively large incision in the abdominal cavity. Posterior interbody fusion is a fusion technique that does not require a large dorsal incision and allows access to the spine while the patient is in a prone position on the operating table. Posterior interbody fusion thus avoids the need to reposition the patient on the operating table after the anterior interbody fusion procedure.

[0005] In the interbody fusion surgery conventionally performed by the applicant, the intervertebral tissue (disc) between the vertebral bodies is removed with a punch, and then a cage is inserted and / or a bone graft is performed. The cage and / or vertebrae removed during surgery or bone harvested from the pelvis are grafted into the space between the vertebral bodies formed by removing the intervertebral tissue, and finally bone fusion is performed to fix the intervertebral space.

[0006] Here, it is difficult to completely remove the intervertebral tissue during intervertebral dissection. The reason is that if the end plate of the vertebra is removed too far, the cage will fall and become less stable. However, because the intervertebral tissue remains, the bone fusion between the vertebral body and the intervertebral bone graft is extremely slow, and often takes six months to a year or more. The bone fusion rate after interbody fusion was 42% after six months, 79% after one year, and 87% after two years (Kang T. et.al. Arch Osteoporosis (2019) 14: 74).

[0007] On the other hand, it is also believed that destruction of the vertebral endplates and leakage of bone marrow fluid during cage insertion and / or bone grafting allows bone marrow stem cells to be introduced into the intervertebral space, promoting bone fusion. Incidentally, the applicant conducted a patent search regarding interbody fusion surgery and found patent documents 1 to 3, all of which relate to posterior interbody fusion surgery.

[0008] In Patent Document 1, the perforator rotates a cutting drill from the rear of adjacent vertebrae to cut the end plates of both vertebrae that sandwich the intervertebral disc. Patent document 2 discloses that forceps with a socket member attached to its tip are inserted into a gap formed by removal of intervertebral tissue (disc), and the forceps is manipulated to perforate the end plate of the vertebra with the sharp portion of the socket member.

[0009] Patent document 3 discloses that a hole is obliquely drilled into the end plate of the upper vertebra with a bone screw that is oriented diagonally upward, and a hole is obliquely drilled into the end plate of the lower vertebra with a bone screw that is oriented diagonally downward. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 7-8514 [Patent Document 2] U.S. Pat. No. 3,875,595 [Patent Document 3] Special Publication No. 2018-532492 Summary of the Invention [Problem to be solved by the invention]

[0011] In Patent Document 1, a cutting drill is rotated along the surface of the vertebral end plate to destroy the entire end plate. Therefore, when a cage is inserted, it sinks into the vertebra, making the cage unstable and narrowing the space between the vertebrae, causing the screws to loosen and making it impossible to maintain the distance between the vertebrae, or causing a loss of fixing force and delaying bone fusion.

[0012] In Patent Document 2, the purpose is to place a bag between vertebrae to fix the vertebrae, and bone fusion is not possible. In other words, the socket member is driven into the end plate of the vertebrae, and part of the bag is inserted into the socket member to position the bag, and bone fusion is not anticipated.

[0013] In the method of Patent Document 3, bone screws must be placed obliquely to the end plates of the upper and lower vertebrae to drill holes in the end plates. This means that the bone screws may pass close to the nerves, which may cause damage to the nerves, making the surgical procedure difficult.

[0014] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve the above-mentioned problems, that is, to provide an endplate drilling instrument that can safely and easily promote intervertebral bone fusion by forming a bone hole that is approximately perpendicular to the endplate. [Means for solving the problem]

[0015] In order to solve the above problems, the end plate perforator of the present invention is an end plate perforator comprising a pipe, an operating portion provided at one end of the pipe, and a case provided at the other end of the pipe, wherein the case has a needle member for perforating the end plate of a vertebra, and the needle member is configured to be freely extended and retracted in a direction approximately perpendicular to an insertion surface of the case which is parallel to the end plate of the vertebra by operating the operating portion.

[0016] According to the above-mentioned configuration, the force of the needle member moving in and out is transmitted to the end plate of the vertebra without any escape, so that the end plate of the vertebra can be reliably drilled to form a bone hole. Then, bone marrow fluid flows out of the drilled bone hole, promoting bone fusion.

[0017] Furthermore, although the needle member pierces the end plate of the vertebra to form a bone hole, the entire end plate of the vertebra is not destroyed, so that even if the cage is inserted after the bone hole is formed, there is no risk of the cage sinking into the vertebra.

[0018] In addition, the needle member is configured to be freely retracted in a direction approximately perpendicular to the insertion surface of the case, which is parallel to the end plates of the vertebrae, so that bone holes can be reliably drilled in the end plates of the vertebrae without damaging the nerves extending in the alignment direction of the vertebrae.

[0019] The length of the needle member when protruding is desirably long enough to penetrate the end plate of the vertebrae. Depending on the thickness of the end plate of the patient's vertebrae, the length is 1 mm to 15 mm, preferably 3 mm to 10 mm, and more preferably 4 mm to 7 mm.

[0020] The thickness of the needle member is desirably a thickness that does not destroy the endplates of the vertebrae while maintaining the strength of the needle member body. Depending on the strength of the endplates of the patient's vertebrae, the thickness is 0.5 mm to 10 mm, preferably 1 mm to 5 mm, and more preferably 1 mm to 2 mm.

[0021] Furthermore, the number and layout of needle members can be adjusted depending on the thickness, area, etc. of the patient's vertebral endplates. For example, for patients with thin endplates, the number of needle members can be reduced and the spacing between the needle members can be increased, and for patients with thick endplates, the number of needle members can be increased and the spacing between the needle members can be reduced. Effect of the Invention

[0022] The end plate perforator of the present invention is easy to operate and can form bone holes that are approximately perpendicular to the end plate, thereby safely and easily promoting subsequent intervertebral bone fusion by forming bone holes that are approximately perpendicular to the end plate. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2A is a plan view of the endplate perforator of the first embodiment, and FIG. 2B is a side view of the endplate perforator of the first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the operating member side of the endplate perforator of the first embodiment. [Diagram 3] FIG. 2 is a perspective view of the case side of the endplate perforator of the first embodiment. [Figure 4] FIG. 2 is a side view of the actuator case when the needle member of the endplate perforator of the first embodiment is located in the buried position. [Diagram 5] 1 is a side cross-sectional view of the actuator case when the needle member of the endplate perforator of the first embodiment is located in the buried position. FIG. [Figure 6] FIG. 2 is a side view of the actuator case when the needle member of the endplate perforator of the first embodiment is located in the protruding position. [Figure 7] 1 is a side cross-sectional view of the actuator case when the needle member of the endplate perforator of the first embodiment is located in the protruding position. FIG. [Figure 8] FIG. 13 is an explanatory diagram showing a plan view of an end plate perforator being inserted between vertebral bodies. [Figure 9] FIG. 13 is an explanatory diagram showing a side view of an endplate perforator being inserted between the vertebral bodies. [Figure 10] FIG. 13 is an explanatory diagram showing a side view of an endplate perforator inserted between vertebral bodies with a needle member protruding upward. [Figure 11] FIG. 13 is an explanatory diagram showing a side view of the endplate perforator inserted upside down between the vertebral bodies with the needle member protruding downward. [Figure 12] FIG. 13 is an explanatory diagram of the state in which the cage is inserted between the vertebral bodies. [Figure 13] FIG. 13 is a longitudinal cross-sectional view of the endplate perforator of the second embodiment when the needle member is in the buried position. [Figure 14]FIG. 11 is a side cross-sectional view of the actuator case when the needle member of the endplate perforator of the second embodiment is located in the protruding position. [Figure 15] FIG. 11 is a cross-sectional view of a main portion showing the relationship between the spline shaft receiving hole of the needle member and the spline shaft in the endplate perforator of the second embodiment. [Figure 16] FIG. 13 is a side view of the actuator case when the needle member of the endplate perforator of the third embodiment is in the buried position. [Figure 17] FIG. 11 is a side view of the actuator case when the needle member of the endplate perforator of the third embodiment is located in the extended position. [Figure 18] Intraoperative image of a case in which an endplate perforator was used to drill into the upper vertebral body. [Figure 19] An image taken three months later, showing bone fusion between the vertebral body and some of the bone within the intervertebral space. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] (First embodiment) An endplate perforator 10 according to a first embodiment of the present invention will now be described with reference to FIGS.

[0025] 1(a) and 1(b), the endplate perforator 10 includes a shaft portion 20 and an actuating portion 40 provided at the tip of the shaft portion 20. In this specification, the direction facing the actuating portion 40 is defined as the front, the direction facing the shaft portion 20 is defined as the rear, the right side when facing forward is defined as the right side, and the opposite side is defined as the left side. In addition, the vertical relationship of the members related to the endplate perforator 10 is defined as follows when the endplate perforator 10 is placed so that a needle member 60 (described later) faces upward.

[0026] (shaft part 20) As shown in Figures 1(a), 1(b) and 2, the shaft portion 20 has a large-diameter gripping tube 21 and a small-diameter extension tube 22 that is coaxially and integrally connected to the front end of the gripping tube 21. The gripping tube 21 has a large-diameter tube hole 21a arranged on the rear end side and a small-diameter tube hole 21b arranged on the front end side. The tube holes 21a and 21b are arranged coaxially. The tube hole 21a of the gripping tube 21 opens at the base end surface (front end surface) of the gripping tube 21, and the tube hole 21b is connected to the tube hole 22a of the extension tube 22.

[0027] The total length of the gripping tube 21 and the extension tube 22 is set to a length sufficient for performing posterior interbody fusion surgery. The gripping tube 21 and the extension tube 22 correspond to pipes. As shown in Fig. 2, a cylindrical operating member 23 is inserted into the tube hole 21a of the grip tube 21 so as to be rotatable around the axis of the grip tube 21. The rear end of the operating member 23 protrudes to the outside from the opening of the tube hole 21a. The rear end of the operating member 23 protruding to the outside from the opening of the tube hole 21a has a cross shape as shown in Fig. 1(a) because an operating handle 24 is fixed through it in the radial direction. The operating member 23 and the operating handle 24 correspond to an operating unit.

[0028] As shown in Fig. 2, a circumferential groove 23a is recessed on the outer peripheral surface of the operating member 23 at the portion inserted into the tube hole 21a. A pair of female screw holes 26 are radially formed on the outer peripheral surface of the gripping tube 21. A setscrew 27 is screwed into each female screw hole 26. The tip of the setscrew 27 is inserted into the circumferential groove 23a of the operating member 23, preventing the gripping tube 21 in the operating member 23 from moving in the axial direction. The number of female screw holes 26 is not limited to two, and may be one or more.

[0029] As shown in FIG. 2, a female screw hole 28 is threaded along the axial direction on the end face of the inner end (front end) of the operating member 23. An operating rod 30 is inserted into the pipe holes 21a, 21b, 22a of the gripping tube 21 and the extension tube 22 so as to be linearly movable along the axial direction of the gripping tube 21 and the extension tube 22. One end of the operating rod 30 is threaded with a male screw 31, and is threaded into a female screw hole 28 of the operating member 23 so as to be freely threaded and retracted. The male screw 31 may be either a right-handed screw or a left-handed screw. The female screw hole 28 is a right-handed screw or a left-handed screw depending on the thread shape of the male screw 31.

[0030] As shown in Figs. 1(a) and 2, a restriction hole 33 communicating with the tube hole 21b is provided in the outer circumferential surface of the front end of the grip tube 21 in the axial direction in the shape of an elongated hole. A pin 34 is fixed to protrude radially from a portion of the operating rod 30 disposed in the tube hole 21b. The pin 34 is fitted into the restricting hole 33, and the gripping tube 21 is allowed to reciprocate in the axial direction within the range of the length defined in the axial direction. This allows the operating rod 30 to reciprocate in the axial direction of the gripping tube 21 within the range of the length of the restricting hole 33.

[0031] In addition, the pin 34 is restricted by the restriction hole 33, so that the operating rod 30 cannot rotate about the axis of the grip tube 21. In other words, when the operating member 23 is rotated about the axis of the grip tube 21, the operating rod 30 cannot rotate with it.

[0032] Therefore, by the operation member 23 being rotated back and forth around the axis of the grip tube 21, the operation rod 30 is screwed back and forth with respect to the operation member 23 within the length range of the restriction hole 33 due to the screwing relationship between the male screw 31 and the female screw hole 28. Position P1 when the pin 34 is positioned in contact with the rear end face of the restriction hole 33 is the first position of the operation rod 30. Position P2 when the pin 34 is positioned in contact with the front end face of the restriction hole 33 is the second position of the operation rod 30. Note that positions P1 and P2 of the pin 34 are not limited to positions in contact with the restriction hole 33, and may be positions spaced from the end faces of the restriction hole 33.

[0033] (Operating part 40) As shown in FIGS. 3 to 7, the actuating section 40 includes an actuating section case 41 as a case, and a mechanism section 42 and a needle member 60 housed in the actuating section case 41. As shown in FIG.

[0034] As shown in Figures 1(a), 1(b) and 3, the actuating section case 41 is integrally connected to the tip of the extension tube 22. The actuating section case 41 has an upper side wall 41a, a lower side wall 41b, a left side wall 41c, a right side wall 41d and a front wall 41e, and is formed in a substantially rectangular parallelepiped shape. The rear part of the actuating section case 41 is tapered so as to taper toward the extension tube 22, and is fixed so as to communicate with the tube hole 22a of the extension tube 22. The vertical length (height) of the actuating section case 41 is set to a size that allows it to be inserted between the vertebrae.

[0035] The mechanism 42 comprises a parallel link mechanism as a retractable means, which is composed of an upper link 43 and a lower link 44 arranged in parallel, and a pair of front links 45 and a pair of rear links 46 pivotally attached to the front and rear parts of the left and right sides of the upper link 43 and the lower link 44. While Fig. 5 and Fig. 7 only show the combination of the front link 45 and the rear link 46 located on the left side of the upper link 43 and the lower link 44, Fig. 3 shows the combination of the front link 45 and the rear link 46 located on the right side of the upper link 43 and the lower link 44.

[0036] The distance between the pivot points of the front link 45 to the upper link 43 and the lower link 44 is the same as the distance between the pivot points of the rear link 46 to the upper link 43 and the lower link 44. In addition, the distance between the pivot points of the upper link 43 to the front link 45 and the rear link 46 is the same as the distance between the pivot points of the lower link 44 to the front link 45 and the rear link 46.

[0037] A pair of needle members 60 are integrally erected at the front and rear of the upper surface of the upper link 43. Both needle members 60 have the same size and height. As shown in Figs. 3 and 5, a pair of windows 62, 63 are provided at the upper side wall 41a of the operating unit case 41 at the opposing portions of the needle members 60. The outer surface of the upper side wall 41a becomes the side surface facing the end plate during surgery, and becomes a parallel insertion surface by being arranged parallel to the end plate. The windows 62, 63 are formed to a size that allows each needle member 60 to protrude to the outside when each needle member 60 moves upward, as shown in Figs. 6 and 7. The needle members 60 are freely retractable in a direction approximately perpendicular to the outer surface of the upper side wall 41a.

[0038] As shown in FIG. 3, the upper side wall 41a has an interference avoidance hole 65 formed in a long hole shape in the upper portion above the front link 45 and the rear link 46, so that the upper portions of the front link 45 and the rear link 46 do not interfere with the upper side wall 41a when they move upward.

[0039] 3, 5 and 7, a connecting link 48 is journaled between the rear end of the lower link 44 and the front end of the operating rod 30. That is, a pair of bifurcated journal portions 44a, 30a are formed at the rear end of the lower link 44 and the front end of the operating rod 30, and the front and rear ends of the connecting link 48 are sandwiched between the journal portions 44a and in the journal portion 30a and are connected to each other by shafts 48a, 48b so as to be able to swing freely. When the operating rod 30 is operated to move from the first position to the second position, the lower link 44 is pushed and moved via the connecting link 48, and conversely, when the operating rod 30 is operated to move from the second position to the first position, the lower link 44 is pulled and moved.

[0040] As shown in Fig. 3, in the upper link 43 and the lower link 44, the shafts 50, 51 that rotatably connect the front link 45 are slidably inserted into guide grooves 54 formed in the left side wall 41c and the right side wall 41d of the actuator case 41, respectively. The relationship between the shafts 50, 51 and the guide grooves 54 will be described in detail later. Note that only the guide groove 54 formed on the left side wall 41c is shown in Figs. 4 to 7.

[0041] 4, the guide groove 54 has a first guide 55, a second guide 56, and a third guide 57. The first guide 55 extends in the vertical direction, and the shaft 50 is inserted between the upper and lower ends thereof so as to be movable up and down.

[0042] The second guide 56 is connected to the lower end of the first guide 55 and extends obliquely downward and rearward. That is, the front end of the second guide 56 is located higher than the rear end. The third guide 57 is connected to the rear end of the second guide 56 and extends linearly rearward. The shaft 51 is movably engaged between the front end of the second guide 56 and the rear end of the third guide 57.

[0043] (Operation of the parallel link mechanism) Here, the operation of the parallel link mechanism of this embodiment will be described. The following explanation will mainly focus on the operation and position of the shafts 50, 51 of the front link 45. Note that explanations of the shafts of the rear link 46 corresponding to the shafts 50, 51 will be omitted because the upper link 43, lower link 44, front link 45 and rear link 46 form a parallel link mechanism. The upper and lower shafts of the rear link 46 should be considered to be synchronous with the shafts 50, 51 and positioned at the same height.

[0044] When the pin 34 is located at position P1 shown in FIG. 2, that is, when the operating rod 30 is located at the first position, the shaft 51 is located at the rear end of the third guide 57, and the shaft 50 is located at the lower end of the first guide 55, as shown in FIGS. 3 to 5.

[0045] When the shaft 50 is located at the lower end of the first guide 55, the upper link 43 is located in a lower position as shown in Figures 3 to 5, i.e., the needle member 60 is located in a recessed position where it does not protrude outward from the windows 62, 63.

[0046] 2, that is, when the operating rod 30 is in the second position, the shaft 51 is located at the front end of the second guide 56 and the shaft 50 is located at the upper end of the first guide 55, as shown in Figures 6 and 7. As a result, the upper link 43 is located at the upper position as shown in Figures 6 and 7, that is, the needle member 60 is located at a protruding position protruding outward from the windows 62, 63. This protruding position is set so that the amount of protrusion of the needle member 60 from the upper side wall 41a is equal to or greater than the thickness of an end plate S, which will be described later.

[0047] 2, that is, when the operating rod 30 is operated from the first position to the second position, the lower link 44 is pressed against the operating rod 30 via the connecting link 48. This causes the shaft 51 to move from the rear end to the front end of the third guide 57, and further from the rear end to the front end of the second guide 56. When the shaft 51 moves through the second guide 56, it gradually rises and moves to the front end of the second guide 56. The advancement and rise of the shaft 51 causes the lower link 44 to move forward and upward.

[0048] Meanwhile, as shaft 50 is moved from the lower end to the upper end of first guide 55, upper link 43 moves to the upper position (see FIG. 7). This upward movement of upper link 43 moves needle member 60 to the protruding position where it protrudes from windows 62, 63. The direction of reciprocating movement of needle member 60 between the buried position and the protruding position is set by mechanism 42 to be perpendicular to the axial direction of gripping tube 21 of operating rod 30.

[0049] When the operating rod 30 is operated so that the pin 34 moves from position P2 to position P1 shown in Figure 2, i.e., when the operating rod 30 is operated from the second position to the first position, the lower link 44 is pulled by the operating rod 30 via the connecting link 48.

[0050] As a result, shaft 51 moves from the front end to the rear end of second guide 56, and then from the front end to the rear end of third guide 57. As shaft 51 moves through second guide 56, it gradually descends and moves behind second guide 56. The rearward and downward movement of shaft 51 causes lower link 44 to move rearward and downward. Meanwhile, shaft 50 is moved from the upper end to the lower end of first guide 55, causing upper link 43 to move to a lower position (see FIG. 5). This movement of upper link 43 to a lower position causes needle member 60 to move to a recessed position where it does not protrude from windows 62, 63.

[0051] (Operation of the first embodiment) Next, a method of using the endplate perforator 10 configured as described above will be described with reference to FIGS.

[0052] As shown in Figures 8 and 9, the surgeon inserts the endplate perforator 10 from the dorsal side into a space formed by dissection of intervertebral tissue t with a punch (not shown) with the needle member 60 in the buried position facing upward. Then, as shown in Figure 9, the surgeon makes the needle member 60 in the buried position of the endplate perforator 10 face the endplate S of the upper vertebral body v. In this state, the surgeon rotates the operating handle 24 and the operating member 23 shown in Figure 1 to move the operating rod 30 from the first position to the second position.

[0053] As a result, the lower link 44 of the parallel link mechanism is pressed by the operating rod 30 via the connecting link 48, causing the upper link 43 to move upward to position the needle member 60 at the protruding position. As a result, as shown in Fig. 10, the needle member 60 penetrates the end plate S of the upper vertebral body v and forms a bone hole Sa approximately perpendicular to the end plate S.

[0054] 1 in the direction opposite to that when the needle member 60 was projected, thereby moving the operating rod 30 from the second position to the first position. As a result, the lower link 44 of the parallel link mechanism is pulled by the operating rod 30 via the connecting link 48, and the upper link 43 is moved downward to position the needle member 60 at the buried position.

[0055] Next, the surgeon rotates the endplate perforator 10 180 degrees to face downward so that the needle member 60 in the implanted position faces the endplate S of the lower vertebral body v. In this state, the surgeon rotates the operating handle 24 and the operating member 23 shown in Fig. 1 to move the operating rod 30 from the first position to the second position. As a result, the operating rod 30 presses the lower link 44 of the parallel link mechanism via the connecting link 48, and the upper link 43 moves from the embedded position to the protruding position, and the needle member 60 penetrates the end plate S of the lower vertebral body v and forms a bone hole Sa approximately perpendicular to the end plate S, as shown in Fig. 11.

[0056] After that, the surgeon rotates the operating handle 24 and the operating member 23 shown in FIG. 1 in the opposite direction to the operation when the needle member 60 is projected, and moves the operating rod 30 from the second position to the first position. As a result, the lower link 44 of the parallel link mechanism is pulled by the operating rod 30 via the connecting link 48, and the needle member 60 is placed at the buried position. After that, the surgeon removes the end plate perforator 10 from between the vertebral bodies, and then inserts the cage K into the intervertebral space by the cage holder (not shown) as shown in FIG. 12, and transplants the graft bone into the cage K and between the vertebral bodies. When the bone hole Sa is formed substantially perpendicular to the end plate S as described above, the bone marrow blood in the cancellous bone of the vertebral body v is introduced into the graft bone between the vertebrae through the bone hole Sa, promoting bone fusion between the vertebrae and fixing the intervertebral space.

[0057] This embodiment has the following features. (1) The endplate perforator 10 of this embodiment includes an actuation case 41 having an upper sidewall 41a with sides facing the endplates of both vertebrae when inserted between adjacent vertebrae, a gripping tube 21 and an extension tube 22 (pipe) integrated with the actuation case 41, and an operating rod 30 inserted into the gripping tube 21 and the extension tube 22 so as to be freely reciprocating. The endplate perforator 10 also includes a needle member 60 that is movably disposed within the actuation case 41 and is movably disposed between an embedded position embedded within the actuation case 41 and a protruding position where the tip protrudes from the upper sidewall 41a. The endplate perforator 10 includes a mechanism 42 that is disposed within the actuation case 41, links the needle member 60 and the operating rod 30, and causes the needle member 60 to reciprocate between the embedded position and the protruding position by the reciprocating movement of the operating rod 30.

[0058] According to the above configuration, when the operating rod 30 is operated in one direction after the operating part case 41 is inserted between the vertebrae and the upper side wall 41a of the operating part case 41 is brought into a state facing the end plate of the vertebra, the mechanism 42 moves the needle member 60 from the buried position to the protruding position. By moving the needle member 60 to the protruding position, the needle member 60 drills a hole in a state substantially perpendicular to the end plate of the vertebra facing the side surface of the upper side wall 41a of the operating part case 41. After the end plate is drilled, when the operating rod 30 is operated in the opposite direction to the above position direction, the mechanism 42 moves the needle member 60 from the protruding position to the buried position. As a result, when used in posterior interbody fusion, a bone hole substantially perpendicular to the end plate can be formed safely and easily with easy operation. This bone hole can promote bone fusion between the vertebrae.

[0059] (2) In the endplate perforator 10 of this embodiment, the operating rod 30 is arranged so as to be freely movable linearly along the axial direction of the gripping tube 21 and the extension tube (pipe) 22. The needle member 60 is arranged so as to be movable between the protruding position and the recessed position by reciprocating in a direction perpendicular to the axial direction. The mechanism 42 converts the linear movement of the operating rod 30 into the movement of the needle member 60 in the perpendicular direction.

[0060] According to the above configuration, the mechanism 42 converts the movement of the needle member 60 into a movement in a direction perpendicular to the axial direction based on the linear movement of the gripping tube 21 and the extension tube 22 (pipe) of the operating rod 30 along the axial direction. This allows the needle member 60 to protrude between the vertebrae with the side surface of the working part case 41 of the endplate perforator positioned approximately parallel to the endplate of the vertebra.

[0061] (3) The endplate perforator 10 of this embodiment has a parallel link mechanism as its mechanical part. This mechanism can easily achieve the effect of (2) above. (4) In the endplate perforator 10 of this embodiment, the inner end of the operating member 23 is inserted into the gripping tube 21 so as to be rotatable about the axis of the gripping tube 21. One end of the operating rod 30 is screwed into the inner end of the operating member 23 so as to be retractable, and the operating member 23 is rotated back and forth about the axis of the gripping tube 21, so that the operating rod 30 can move back and forth between a first position and a second position.

[0062] According to the above configuration, the operating member 23 is rotated reciprocally around the axis of the gripping tube 21, whereby the operating rod 30 moves reciprocally between the first position and the second position. This enables the needle member 60 to move reciprocally between the buried position and the protruding position via the mechanism 42.

[0063] Second embodiment Next, an endplate perforator 10 of a second embodiment will be described with reference to Figures 13 to 15. Note that the same or corresponding components as those of the first embodiment are given the same reference numerals and detailed description thereof will be omitted.

[0064] As shown in FIG. 13, in this embodiment, in the configuration of the endplate perforator 10 of the first embodiment, the rear end of the operating rod 30 protrudes from the gripping tube 21, and an operating member 23, which is shorter than that of the first embodiment, is fixed integrally to the rear end. A circumferential groove is formed on the outer periphery of the operating rod 30 located inside the gripping tube 21. A pair of female screw holes 26 are provided radially through the outer periphery of the gripping tube 21. A set screw 27 is screwed into each female screw hole 26. The tip of the set screw 27 is inserted into the circumferential groove of the operating rod 30. As a result, the operating rod 30 is prevented from moving in the axial direction of the gripping tube 21, and is freely rotatable around the axial center of the gripping tube 21.

[0065] The actuating section 40 provided at the tip of the extension tube 22 includes an actuating section case 141 as a case, and a mechanism section 150 and a needle member 160 housed within the actuating section case 141 . The actuator case 141 is made of a rectangular parallelepiped block and has an upper side surface 141a, a lower side surface 141b, a left side surface, a right side surface, a front side surface 141e, and a rear side surface 141f. A bevel gear storage hole 142 extending in the front-rear direction is formed in the actuator case 141. A pair of front and rear drive bevel gears 143 integrally connected to the front end of the operating rod 30 are stored in the bevel gear storage hole 142.

[0066] Further, a pair of needle member storage holes 144 are formed in the front and rear of the actuation unit case 141, which communicate with the bevel gear storage hole 142. An upper side surface 141a is opened in the needle member storage hole 144. The upper side surface 141a is the side surface facing the end plate during surgery, and is disposed parallel to the end plate during surgery to form a parallel insertion surface.

[0067] In each needle member storage hole 144, a needle member 160 is stored so as to move up and down while rotating, and can freely appear and disappear in a direction approximately perpendicular to the upper side surface 141a. That is, a spiral groove 147 is formed on the side surface of the needle member 160 from the center in the up and down direction to the base end, and is engaged with a spiral groove 144a formed on the inner surface of the needle member storage hole 144. The base end surface of the needle member 160 is provided with a spline shaft storage hole 149 extending to the tip along the axial direction. As shown in FIG. 15, the spline shaft storage hole 149 is fitted to a spline shaft 148a integrally provided with the driven bevel gear 148, so that the needle member 160 is freely movable along the axial direction. The driven bevel gear 148 is engaged with the drive bevel gear 143. The drive bevel gear 143 and the driven bevel gear 148 constitute a bevel gear mechanism.

[0068] When the driving bevel gear 143 is rotated via the operating rod 30 by the reciprocating rotational operation of the operating handle 24 and the operating member 23, the rotational motion is transmitted to the driven bevel gear 148. Then, when the rotational motion is transmitted from the spline shaft 148a provided on the driven bevel gear 148 to the needle member 160, the needle member 160 rotates. Furthermore, when the needle member 160 rotates, a driving force in the vertical direction is generated by the spiral groove, and the needle member 160 moves up and down while rotating between a buried position where it is buried in the actuation part case 141 as shown in Fig. 13 and a protruding position as shown in Fig. 14.

[0069] In the end plate perforator 10 configured as described above, similarly to the first embodiment, when the needle member 160 is operated from the buried position to the protruding position with the needle member 160 facing upward, the end plate S of the upper vertebral body v can be penetrated and a bone hole can be formed approximately perpendicular to the end plate S. When the needle member 160 is operated from the buried position to the protruding position with the needle member 160 facing downward, the end plate S of the lower vertebral body v can be penetrated and a bone hole can be formed approximately perpendicular to the end plate S.

[0070] In the end plate perforator 10 of this embodiment, the needle member 160 can be moved up and down while being rotated, and by making the needle member 160 into a drill shape, a bone hole can be reliably formed in the end plate of the vertebra.

[0071] Third embodiment The third embodiment will be described with reference to Figures 16 and 17. This embodiment differs from the first embodiment in that a cam mechanism is formed as the mechanical part 42 in the configuration of the endplate perforator 10. Examples of the cam mechanism as the projection and recession means include a linear cam, a front cam, and a plate cam.

[0072] Figure 16 shows a linear cam configuration as an example of a cam mechanism. A cam plate 70 is integrally formed at the front end of the operating rod 30. The front surface of the cam plate 70 serves as a cam surface 70a. The cam surface 70a is flat and is formed in an inclined shape so that its height decreases toward the front.

[0073] The pair of needle members 60 are arranged side by side on the upper surface of a block-shaped cam follower 72. The rear end lower portion of the cam follower 72 is placed on the cam surface 70a of the cam plate 70, and is arranged so as to be moved upward by the cam surface 70a when the operating rod 30 moves forward. The front surface of the cam follower 72 is in vertically slidable contact with the inner surface of the front wall 41e formed in a flat surface. The cam follower 72 is constantly in contact with the cam surface 70a and the inner surface of the front wall 41e, so that the pair of needle members 60 are at the same height. A pair of guide protrusions 76 protrude from both the left and right side surfaces of the cam follower 72. The guide protrusions 76 are slidably inserted into guide holes 77 formed in the vertical direction on both the left and right side walls of the actuation unit case 41.

[0074] As shown in Fig. 16, when the operating rod 30 is located at the first position (see Fig. 2) as in the first embodiment, the needle member 60 is located at the recessed position. Also, as shown in Fig. 17, when the operating rod 30 is located at the second position as in the first embodiment, the needle member 60 is located at the protruding position protruding from the upper side wall 41a.

[0075] A coil spring 78 is disposed between the top surface of the cam follower 72 and the inner surface of the upper side wall 41a as a biasing member. The cam follower 72 is constantly biased toward the lower side wall 41b by the coil spring 78. Even with this configuration, the same effect as that of (1) of the first embodiment can be obtained.

[0076] (Results of actual use) Fig. 18 is an image taken during surgery in which the endplate perforator of the first embodiment is used to perforate the upper vertebral body, and a perforation (perforation portion) is formed in the endplate. As shown in the figure, a perforation (perforation portion) is formed that is approximately perpendicular to the endplate. In this surgery, bone fusion between the vertebral body and a part of the bone in the intervertebral space was confirmed three months after the bone graft was performed between the vertebrae, as shown by the arrow in Fig. 19.

[0077] From this, it can be said that bone marrow blood from the cancellous tissue of the vertebral body is introduced into the intervertebral bone graft through the perforation (perforation portion) formed in the end plate by the end plate perforator, promoting bone union earlier than in the conventional example described in the background art.

[0078] This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other to the extent that no technical contradiction occurs.

[0079] For example, the configuration of the first embodiment may be added with a second parallel link mechanism operated by an operating rod 30 that moves back and forth in a straight line, and a second needle member implanted in the parallel link mechanism, and a configuration in which the second needle member is protruded from the buried position from the lower side wall 41b to a downward protruding position. [Explanation of symbols]

[0080] 10…Endplate perforator 20…Shaft section 21...Holding pipe 21a…Pipe hole 21b…Pipe hole 22…Extension pipe 23...Operation member (operation part) 24...Operation handle (operation part) 26...Female screw hole 27…Setscrew 28…Female screw hole 30…Operation rod 31…Male thread 33...Restriction hole 34…Pin 40...Operating part 41...Operating part case (case) 42... Mechanism section 43…Top link 44…Bottom link 44a…Axis branch 45…Front link 46…Rear link 48…Connecting link 48a…axis 50…Axis 51...Axis 54...Guide groove 55…First Guide 56…Second Guide 57…Third Guide 60...Needle member 62…Window 63…Window 65…Interference avoidance hole 70…Cam surface 70a…Cam surface 72…Cam follower 76…Guide protrusion 77...Guide hole 78...Coil spring 141...Operating unit case 141a…Top side 141b…lower side 141c…Left side 141d…Right side 141e…Front side 142...Bevel gear storage hole 143...Drive bevel gear 148...Driven bevel gear 150... Mechanism section 160...needle member

Claims

1. Pipes and An operating unit provided at one end of the pipe; and an actuating portion provided at the other end of the pipe, The actuation unit includes a case, a needle member for perforating an end plate of a vertebra, and a mechanism unit that is housed in the case and moves the needle member by operating the operation unit. the needle member has a length capable of penetrating an end plate of a vertebra when protruding, and is configured to be freely protruding and retracting in a direction substantially perpendicular to an insertion surface of the case that is parallel to the end plate of the vertebra; The needle members are spaced apart from each other.

2. A pipe, An operating unit provided at one end of the pipe; and an actuating portion provided at the other end of the pipe, The actuation unit includes a case, a needle member for perforating an end plate of a vertebra, and a mechanism unit that is housed in the case and moves the needle member by operating the operation unit. The needle member is configured to be freely inserted and removed in a direction substantially perpendicular to an insertion surface of the case that is parallel to an end plate of the vertebrae, The mechanism unit includes: an upper link on which the needle member is erected; A lower link disposed parallel to the upper link and connected to the operation unit; a pair of front links and a pair of rear links rotatably attached to left and right side surfaces of the upper link and the lower link, respectively; An endplate perforator comprising a parallel link mechanism comprising:

3. A pipe, An operating unit provided at one end of the pipe; and an actuating portion provided at the other end of the pipe, The actuation unit includes a case, a needle member for perforating an end plate of a vertebra, and a mechanism unit that is housed in the case and moves the needle member by operating the operation unit. The needle member is configured to be freely inserted and removed in a direction substantially perpendicular to an insertion surface of the case that is parallel to an end plate of the vertebrae, The mechanism unit includes: a cam follower on which the needle member is erected; A cam plate connected to the operation portion, The cam plate has a cam surface which is an inclined plane whose height decreases toward the front, A rear end lower portion of the cam follower is placed on the cam surface. An endplate perforator including a cam mechanism.

4. A pipe, An operating unit provided at one end of the pipe; and an actuating portion provided at the other end of the pipe, The actuation unit includes a case, a needle member for perforating an end plate of a vertebra, and a mechanism unit that is housed in the case and moves the needle member by operating the operation unit. The needle member is configured to be freely inserted and removed in a direction substantially perpendicular to an insertion surface of the case that is parallel to an end plate of the vertebrae, The mechanical portion includes a bevel gear mechanism that rotates the needle member, and the needle member protrudes and retracts from the insertion surface while rotating.

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