Structure for detecting orientation of intervertebral spacer

Abstract

To provide a structure allowing an operator to quickly and easily detect orientation of an intervertebral spacer in both manners of visual observation and X-ray photography.SOLUTION: A structure for detecting orientation of an intervertebral spacer has a single columnar shape, and includes one end face 2 formed into a substantially rectangular shape and the other end face 3 formed into a substantially triangular shape. Two edge lines 6a and 6b that extend between both end points 4a and 4b of one side 4 of the quadrangle on the one end face 2, and both end points 5a and 5b of a side 5 of the triangle on the other end face 3, respectively facing both end points 4a and 4b of the one side 4, do not intersect with each other, while two edge lines 8a and 8b that extend between both end points 7a and 7b of a side 7 facing the side 4 of the quadrangle on the one end face 2, and a vertex 5c other than both end points 5a on 5b of the triangle on the other end face 3, form a V shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a structure that is used in spinal fixation surgery and is pre-assembled into an intervertebral spacer that is placed between the vertebral bodies of a patient, and functions as a marker for detecting the orientation of the intervertebral spacer. [Background technology]

[0002] Spinal injuries can be classified as injuries caused by diseases such as trauma, degeneration, and tumors, or injuries caused by surgical procedures to treat them (damage caused when ligaments, joints, etc. are unavoidably removed during surgery). One of the treatments for such spinal injuries is spinal fixation surgery.

[0003] Spinal fusion is a surgical procedure that involves connecting and fusing two or more unstable vertebral bodies together using intervertebral spacers.

[0004] Known examples of conventional intervertebral spacers include a frame-shaped spacer consisting of a front wall, a rear wall, and a pair of side walls extending between the front and rear walls, with an opening extending up and down on the inside, with a plurality of teeth provided on the upper and lower end surfaces of the pair of side walls, and with one or more openings in each side wall that communicate with the opening on the inside (see, for example, Patent Documents 1 and 2); and a spacer consisting of a solid front wall, a solid rear wall, a solid inner wall, and a solid outer wall, with a frame portion having a cavity in the center, and with a porous material filled in the cavity in the center of the frame portion (see, for example, Patent Document 3).

[0005] In spinal fusion surgery, one or more intervertebral spacers are placed between the target vertebral bodies of the patient. In this case, before the intervertebral spacer is placed inside the patient's body, the doctor visually confirms the placement direction of the intervertebral spacer (checking the front-to-back and up-down orientation of the intervertebral spacer) and ensures that the intervertebral spacer is placed accurately in the specified position and in the correct orientation.

[0006] Furthermore, if necessary, an X-ray machine is used during placement of the intervertebral spacer, and the direction of the intervertebral spacer is reconfirmed and the position is adjusted while viewing the images obtained.

[0007] The intervertebral spacer engages with the two adjacent vertebral bodies on the upper and lower surfaces, keeps the relative positional relationship between the two vertebral bodies constant, and promotes bone growth in the patient. After a certain period of time has passed after surgery, the two vertebral bodies fuse with each other via the intervertebral spacer, thereby completing the fixation of the two vertebral bodies.

[0008] In the case of prefabricated intervertebral spacers, the front-to-back and up-down orientations can generally be easily determined by visual inspection from their external shape. However, in the case of custom-made products that are designed and manufactured for each patient based on three-dimensional X-ray images of the patient's spine, it is sometimes not easy to determine the front-to-back and up-down orientations by visual inspection from their external shape.

[0009] Therefore, in the prior art, in order to distinguish the front / back and up / down orientations of the intervertebral spacer, for example, the front and / or top surface of the intervertebral spacer is provided with markings or engraved with markings.

[0010] However, depending on the intervertebral spacer, it may not be possible to provide a rugged mark or to mark it with an engraving, and the rugged mark or engraving may be difficult to see in an X-ray image. In such cases, there is a problem that the orientation of the intervertebral spacer cannot be quickly and easily determined by visual inspection or X-ray photography. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Patent No. 4378343 [Patent Document 2] JP 2016-135243 A [Patent Document 3] JP 2019-55191 A (paragraphs 0027, 0033, 0035 to 0036, Figs. 8 to 10, 26A to 27, and 32 to 35) Summary of the Invention [Problem to be solved by the invention]

[0012] Therefore, an object of the present invention is to make it possible to quickly and easily detect the orientation of an intervertebral spacer both visually and by X-ray photography. [Means for solving the problem]

[0013] In order to solve the above problems, the present invention provides a structure that is pre-installed in an intervertebral spacer to be placed between the vertebrae of a patient and functions as a marker to detect the orientation of the intervertebral spacer, the structure being a single columnar structure, with one end face formed in a substantially rectangular shape or a shape that would become substantially a rectangular shape if adjacent vertices were connected to each other by straight lines, and the other end face formed in a substantially triangular shape or a shape that would become substantially a triangle if adjacent vertices were connected to each other by straight lines, and two ridge lines extending between both end points of one side of the rectangle at the one end face and both end points of the sides of the triangle at the other end face that are opposite to the both end points of the one side do not intersect each other, and two ridge lines extending between each of the end points of the side opposite to the one side of the rectangle at the one end face and a vertex that is not the end point of the triangle at the other end face form a V-shape.

[0014] According to a preferred embodiment of the present invention, the one end surface is formed in an X-shape, and the other end surface is formed in a V-shape.

[0015] According to another preferred embodiment of the present invention, the one end surface is formed in an X-shape and the other end surface is formed in a Y-shape.

[0016] According to yet another preferred embodiment of the present invention, a through hole is formed, both ends of which are open to the one end surface and the other end surface, respectively.

[0017] According to yet another preferred embodiment of the present invention, another through hole is formed extending in a direction intersecting the through hole. Effect of the Invention

[0018] The structure according to the present invention is incorporated into an intervertebral spacer, for example, so that one end face of the structure is located on the front side of the intervertebral spacer (exposed) while the other end face of the structure is located on the rear side of the intervertebral spacer (exposed), and so that the two ridges of the structure that extend without intersecting each other are located on the upper side of the intervertebral spacer (which may or may not be exposed on the upper side), while the two V-shaped ridges of the structure are located on the lower side of the intervertebral spacer (which may or may not be exposed on the lower side).

[0019] As a result, when the intervertebral spacer is visually inspected or X-rayed, if the structure is substantially rectangular, or if a shape that would form a substantially rectangular shape if the vertices were connected to each other with straight lines, it can be determined that it is the front side of the intervertebral spacer; if the structure is substantially triangular, or if a shape that would form a substantially triangular shape if adjacent vertices were connected to each other with straight lines, it can be determined that it is the rear side of the intervertebral spacer; furthermore, if two ridgelines of the structure that extend without intersecting each other are visible, it can be determined that it is the top side of the intervertebral spacer; and if two ridgelines of the structure that form a V-shape are visible, it can be determined that it is the bottom side of the intervertebral spacer.

[0020] Thus, according to the present invention, the orientation of the intervertebral spacer can be quickly and easily detected when the intervertebral spacer is visually or X-rayed. Furthermore, since the structure is incorporated into the intervertebral spacer as a part of its internal structure, there is no limitation due to the size of the intervertebral spacer. [Brief description of the drawings]

[0021] [Figure 1]1A and 1B are diagrams showing a structure for detecting the orientation of an intervertebral spacer according to one embodiment of the present invention, in which (A) is a front oblique view seen from diagonally above, (B) is a rear oblique view seen from diagonally above, (C) is a front view, (D) is a rear view, (E) is a top view, and (F) is a bottom view. [Diagram 2] 2 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to another embodiment of the present invention; [Diagram 3] 10 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the present invention. [Figure 4] 10 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the present invention. [Diagram 5] 10 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the present invention. [Figure 6] 4A and 4B show an example of an intervertebral spacer incorporating the structure shown in FIG. 3, where (A) is an oblique view seen from diagonally above the front, (B) is an oblique view seen from diagonally above the rear, (C) is an oblique view seen from diagonally below the front, and (D) is an oblique view seen from diagonally below the rear. [Figure 7] 7 is a view similar to FIG. 6 showing a variation of the intervertebral spacer shown in FIG. 6. [Figure 8] 7A and 7B show X-ray images of the intervertebral spacer shown in FIG. 6, where (A) is an image taken from the front side, (B) is an image taken from the rear side, (C) is an image taken from the top side, and (D) is an image taken from the bottom side. [Figure 9] 8 showing an X-ray image of the intervertebral spacer shown in FIG. 7. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration of the present invention will be described based on preferred embodiments with reference to the accompanying drawings. FIG. 1 shows a structure for detecting the orientation of an intervertebral spacer according to one embodiment of the present invention, where FIG. 1(A) is a front oblique view from above, FIG. 1(B) is a rear oblique view from above, FIG. 1(C) is a front view, FIG. 1(D) is a rear view, FIG. 1(E) is a top view, and FIG. 1(F) is a bottom view.

[0023] As shown in FIG. 1, in this embodiment, a structure 1 according to the present invention has the shape of a single column, one end face 2 of which is formed in a square shape, while the other end face 3 of which is formed in an isosceles triangle shape. The structure 1 is preferably made of a suitable metal material, such as titanium or a titanium alloy, that has affinity with bone and is difficult for X-rays to transmit.

[0024] Furthermore, two ridges 6a, 6b extending between both end points 4a, 4b of one side 4 of the square on one end face 2 of the structure 1 and both end points 5a, 5b of a side (in this embodiment, the base) 5 of an isosceles triangle on the other end face 3 that faces both end points 4a, 4b of the side 4 are parallel, and two ridges 8a, 8b extending between both end points 7a, 7b of a side 7 that faces the side 4 of the square on one end face 2 and a vertex 5c other than the end points 5a, 5b of the isosceles triangle on the other end face 3 form a V-shape.

[0025] Then, the structure 1 is incorporated into the intervertebral spacer so that, for example, one end face 2 is located on the front side of the intervertebral spacer (exposed), while the other end face 3 is located on the rear side of the intervertebral spacer (exposed), and the two parallel ridges 6a, 6b are located on the upper side of the intervertebral spacer (which may or may not be exposed on the upper side), while the two V-shaped ridges 8a, 8b are located on the lower side of the intervertebral spacer (which may or may not be exposed on the lower side).

[0026] Thus, when the intervertebral spacer is visually inspected or X-rayed, if the square shape of structure 1 is visible, it can be determined that it is the front side of the intervertebral spacer, if the isosceles triangular shape of structure 1 is visible, it can be determined that it is the rear side of the intervertebral spacer, and further, if the two parallel ridges 6a, 6b of structure 1 are visible, it can be determined that it is the top side of the intervertebral spacer, and if the two V-shaped ridges 8a, 8b of structure 1 are visible, it can be determined that it is the bottom side of the intervertebral spacer.

[0027] According to the present invention, the orientation of the intervertebral spacer can be quickly and easily detected when the intervertebral spacer is visually or X-rayed. Furthermore, since the structure is incorporated into the intervertebral spacer as a part of its internal structure, there is no limitation due to the size of the intervertebral spacer.

[0028] In this embodiment, one end face 2 of the structure 1 is formed in a square shape, and the other end face 3 is formed in an isosceles triangle shape, but the shapes of both end faces 2, 3 of the structure 1 are not limited to this embodiment, and it is sufficient that one end face 2 of the structure 1 is formed in a substantially rectangular shape, or a shape that would become substantially a rectangular shape if adjacent vertices were connected to each other by straight lines, while the other end face 3 is formed in a substantially triangular shape, or a shape that would become substantially a triangle if adjacent vertices were connected to each other by straight lines.

[0029] FIG. 2 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to another embodiment of the present invention.

[0030] As shown in FIG. 2, in this embodiment, the structure 1' has a columnar shape, one end surface 9 is formed in an X shape, and the other end surface 10 is formed in a V shape. In this case, as can be clearly seen from Figure 2(C), one end face 9 forms a square when adjacent vertices 9a to 9d are connected to each other by straight lines, and as can be clearly seen from Figure 2(D), the other end face 10 forms an isosceles triangle when adjacent vertices 10a to 10c are connected to each other by straight lines.

[0031] The two ridges 13a, 13b extending between both end points 9a, 9b of one side 11 of the square on one end face 9 and both end points 10c, 10b of a side (in this embodiment, the base) 12 of an isosceles triangle on the other end face 10 that faces both end points 9a, 9b of the side 11 are parallel, and the two ridges 15a, 15b extending between both end points 9c, 9d of a side 14 that faces the side 11 of the square on one end face 9 and the vertex 10a other than the end points 10b, 10c of the isosceles triangle on the other end face 10 form a V-shape.

[0032] It goes without saying that this embodiment also provides the same effects as the embodiment of FIG.

[0033] FIG. 3 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the invention.

[0034] As shown in FIG. 3, in this embodiment, a structure 1'' has a columnar shape, one end surface 16 of which is formed in an X shape, while the other end surface 17 of which is formed in a Y shape.

[0035] In this case, as can be clearly seen from Figure 3(C), one end face 16 forms a square when adjacent vertices 16a to 16d are connected to each other by straight lines, and the other end face 17 forms an isosceles triangle when adjacent vertices 17a to 17c are connected to each other by straight lines, as can be clearly seen from Figure 3(D).

[0036] The two edges 20a, 20b extending between both end points 16a, 16b of one side 18 of the square on one end face 16 and both end points 17c, 17b of a side (in this embodiment, the base) 19 of an isosceles triangle on the other end face 17 that faces both end points 16a, 156 of the side 18 are parallel, and the two edges 22a, 22b extending between both end points 16c, 16d of a side 21 that faces the side 18 of the square on one end face 16 and the vertex 17a other than the end points 17b, 17c of the isosceles triangle on the other end face 17 form a V-shape.

[0037] It goes without saying that this embodiment also provides the same effects as the embodiment of FIG.

[0038] FIG. 4 is a view similar to FIG. 1 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the invention. The embodiment in Fig. 4 is obtained by adding another configuration to the embodiment in Fig. 1. Therefore, in Fig. 4, the same components as those shown in Fig. 1 are given the same numbers, and detailed descriptions thereof will be omitted below.

[0039] Referring to Figure 4, in this embodiment, a first through hole 31 having both ends opening to one end face 2 and the other end face 3, respectively, and a second through hole 32 perpendicular to the first through hole 31 are formed in a structure 30.

[0040] In this case, the second through hole 32 has one end opening into a plane defined by side 4 of one end face 2, side 5 of the other end face 3, and two ridges 6a, 6b, and the other end opening into a plane defined by side 7 of one end face 2 and two ridges 8a, 8b.

[0041] Thus, when an intervertebral spacer incorporating the structure 30 is X-rayed in the direction of the first through hole 31, the opening of the first through hole 31 appears as a white dot in the X-ray image, and when the structure 30 is X-rayed in the direction of the second through hole 32, the opening of the second through hole 32 appears as a white dot in the X-ray image.

[0042] Thereby, during surgery, the doctor can easily align the intervertebral spacer within the patient's body by using this white dot as a guide.

[0043] It is noted that only one of the first and second through holes 31, 32 may be provided, or a plurality of first through holes 31 and / or a plurality of second through holes 32 may be provided.

[0044] FIG. 5 is a view similar to FIG. 3 illustrating a structure for detecting the orientation of an intervertebral spacer according to yet another embodiment of the invention. The embodiment in Fig. 5 is obtained by adding another configuration to the embodiment in Fig. 3. Therefore, in Fig. 5, the same components as those shown in Fig. 3 are given the same numbers, and detailed descriptions thereof will be omitted below.

[0045] Referring to Figure 5, in this embodiment, a first through hole 34 having both ends opening to one end face 16 and the other end face 17, respectively, and a second through hole 35 perpendicular to the first through hole 34 are formed in a structure 33.

[0046] It goes without saying that this embodiment also provides the same effects as the embodiment of FIG.

[0047] Figure 6 shows an example of an intervertebral spacer incorporating the structure shown in Figure 3, where Figure 6(A) is an oblique view seen from diagonally above the front, Figure 6(B) is an oblique view seen from diagonally above the rear, Figure 6(C) is an oblique view seen from diagonally below the front, and Figure 6(D) is an oblique view seen from diagonally below the rear. In FIG. 6, the same components as those shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted below.

[0048] Referring to FIG. 6, the intervertebral spacer 40 is comprised of a first end 41a, a second end 41b, a framework structure 42 connecting the first and second ends 41a, 41b, and a porous portion 43 disposed within the space defined by the framework structure 42 and the first and second ends 41a, 41b.

[0049] The structure 1" is integrally incorporated with the framework structure 42 and the porous portion 43 in the center of the intervertebral spacer 40, with one end face 16 positioned exposed on the front surface 40a of the intervertebral spacer 40, while the other end face 17 positioned exposed on the rear surface 40b of the intervertebral spacer, and with two parallel ridges 20a, 20b positioned exposed on the upper surface 40c of the intervertebral spacer 40, while two V-shaped ridges 22a, 22b positioned exposed on the lower surface 40d of the intervertebral spacer.

[0050] In this embodiment, the entire intervertebral spacer 40 is formed using a 3D printer based on three-dimensional additive manufacturing technology from a suitable metal material that has affinity with bone, such as titanium or a titanium alloy. Thus, the structure 1″ is formed integrally with other structural portions of the intervertebral spacer 40 as a part of the internal structure of the intervertebral spacer 40.

[0051] In addition, when the structure 1" and the intervertebral spacer 40 are formed separately (for example, when the intervertebral spacer 40 is made of PEEK and the structure 1" is made of metal), the structure 1" is fitted into a space previously formed in the intervertebral spacer 40 by hammering.

[0052] Thus, when intervertebral spacer 40 is visually observed, if the X-shape (one end face 16) of structure 1" is visible, it can be determined that it is the front surface 40a of intervertebral spacer 40, if the Y-shape (other end face 17) of structure 1" is visible, it can be determined that it is the rear surface 40b of intervertebral spacer 40, and further, if two parallel ridges 20a, 20b of structure 1" are visible, it can be determined that it is the upper surface 40c of intervertebral spacer 40, and if two ridges 22a, 22b forming a V-shape of structure 1" are visible, it can be determined that it is the lower surface 40d of intervertebral spacer 40.

[0053] In this embodiment, each pair of ridges 20a, 20b; 22a, 22b are exposed on the upper surface 40c and the lower surface 40d of the intervertebral spacer 40, respectively. However, in some cases, each pair of ridges 20a, 20b; 22a, 22b may be embedded inside the intervertebral spacer 40', as shown in FIG. 7.

[0054] Fig. 8 shows X-ray images of the intervertebral spacer shown in Fig. 6, with Fig. 8(A) showing an image taken from the front side, Fig. 8(B) showing an image taken from the back side, Fig. 8(C) showing an image taken from the top side, and Fig. 8(D) showing an image taken from the bottom side. Fig. 9 is a view similar to Fig. 8 showing X-ray images of the intervertebral spacer shown in Fig. 7.

[0055] As is clear from Figures 8 and 9, when intervertebral spacers 40, 40' are X-rayed, just as in the case of visual inspection, if the X-shape (one end face 16) of structure 1" is visible, it can be determined that it is the front surface 40a of intervertebral spacer 40, and if the Y-shape (the other end face 17) of structure 1" is visible, it can be determined that it is the rear surface 40b of intervertebral spacer 40. Furthermore, if two parallel ridges 20a, 20b of structure 1" are visible, it can be determined that it is the upper surface 40c of intervertebral spacer 40, and if two ridges 22a, 22b forming a V-shape of structure 1" are visible, it can be determined that it is the lower surface 40d of intervertebral spacer 40. [Explanation of symbols]

[0056] 1, 1', 1” structure 2 One end face 3 Other end surface 4 sides 4a, 4b end points 5 sides 5a, 5b end points 5c Vertex 6a, 6b Ridgeline 7 sides 7a, 7b end points 8a, 8b Ridge 9 One end face 9a~9d Vertex 10 Other end face 10a~10c Vertex Sides 11 and 12 13a, 13b Ridgeline 14 sides 15a, 15b Ridgeline 16 One end face 16a~16d Vertex 17 Other end face 17a~17c Vertex Sides 18 and 19 20a, 20b Ridgeline 21 sides 22a, 22b ridgeline 30 Structure 31 First through hole 32 Second through hole 33 Structure 34 First through hole 35 Second through hole 40, 40' Intervertebral Spacer 40a front 40b rear 40c top 40d bottom surface 41a First end 41b Second end 42 Frame structure 43 Porous part

Claims

1. A structure that is incorporated in advance into an intervertebral spacer that is placed between the vertebral bodies of a patient and functions as a marker for detecting the orientation of the intervertebral spacer, It is shaped like a single pillar. One end face is formed in a substantially quadrangular shape or a shape that would be substantially a quadrangular shape if adjacent vertices were connected to each other with straight lines, while the other end face is formed in a substantially triangular shape or a shape that would be substantially a triangular shape if adjacent vertices were connected to each other with straight lines, two ridge lines extending between both end points of one side of the quadrangle on said one end surface and both end points of the sides of the triangle on said other end surface that face each other do not intersect with each other, A structure characterized in that two ridge lines extending between each of the end points of the side opposite to the one side of the rectangle on the one end face and a vertex other than the end points of the triangle on the other end face form a V shape.

2. 2. The structure according to claim 1, wherein the one end surface is formed in an X-shape and the other end surface is formed in a V-shape.

3. 2. The structure according to claim 1, wherein the one end surface is formed in an X-shape and the other end surface is formed in a Y-shape.

4. 4. The structure according to claim 1, wherein a through hole is formed at both ends, the through hole being open to the one end face and the other end face, respectively.

5. 5. The structure according to claim 4, further comprising another through hole formed in the substrate so as to extend in a direction intersecting the through hole.

Images