Interbody fusion cage

Abstract

The invention relates to an interbody fusion cage which is used for being placed between two vertebral bodies arranged at intervals in the first direction and comprises a fusion cage body abutting face, a fusion cage main body abutting face and a fusion cage main body abutting face, the bone grafting hole penetrates through the fusion cage body in the first direction, the hole wall of the bone grafting hole comprises a plurality of convex areas and a plurality of concave areas, the bone grafting hole is provided with a datum plane, the convex areas protrude out of the datum plane, and the concave areas are concave in the datum plane; the sum of the volume of a first space defined by all the convex areas and the datum plane is larger than the sum of the volume of a second space defined by all the concave areas and the datum plane. According to the interbody fusion cage, the larger contact area between the interbody fusion cage and the vertebral body and the larger bone grafting hole volume can be considered.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to an intervertebral fusion device. Background Art

[0002] As people's living and working habits change in modern society, disc herniation has become an increasingly common disease. Currently, surgery is the main treatment for more severe disc herniation. During surgery, the diseased disc between the two vertebrae is removed and an intervertebral fusion device is implanted in its original position to replace the original diseased disc.

[0003] Usually, the intervertebral fusion device is provided with bone grafting holes that pass through the device. During the operation, bone grafting materials (autologous transplanted bones or artificial bones) will be filled in the bone grafting holes. After the operation, the vertebral bodies on both sides of the intervertebral fusion device will grow into the holes through the openings of the bone grafting holes and fuse with the bone grafting materials, so that the fusion device and the vertebral bodies on both sides are tightly combined. Therefore, the larger the volume of the bone grafting holes, the more bone grafting materials can be filled, and the higher the bonding strength between the fusion device and the vertebral bodies on both sides after the operation. In the related art, the volume of the bone grafting holes is usually increased by increasing the cross-sectional area of ​​the bone grafting holes. However, this will cause the opening of the bone grafting holes to increase, and the contact area between the fusion device and the vertebral body will become smaller, and the fusion device is prone to displacement after the operation. Summary of the invention

[0004] Based on this, it is necessary to provide an intervertebral fusion device that takes into account a larger contact area between the intervertebral fusion device and the vertebral body and a larger bone graft hole volume, so that the intervertebral fusion device has better positional stability after surgery and has better bonding strength with the vertebral body.

[0005] An intervertebral fusion cage is used to be placed between two vertebrae spaced apart along a first direction, the intervertebral fusion cage comprising:

[0006] Fusion device body;

[0007] A bone graft hole, passing through the fusion device body along the first direction, wherein the hole wall of the bone graft hole includes a plurality of convex areas and a plurality of concave areas;

[0008] The bone graft hole has a reference plane, the convex area protrudes from the reference plane, the concave area is recessed from the reference plane, the sum of the volumes of the first space enclosed by all the convex areas and the reference plane is a, the sum of the volumes of the second space enclosed by all the concave areas and the reference plane is b, and a>b.

[0009] In one embodiment, on the longitudinal section of the intervertebral fusion cage, the cross-section of the hole wall of the bone graft hole is at least one of a sine wave, a sawtooth wave, a rectangular wave, a triangle wave, a trapezoidal wave, a bell wave or a truncated sine wave.

[0010] In one embodiment, the cross-sectional area of ​​the bone graft hole at any point along the first direction is c, the opening area of ​​the bone graft hole is d, and c≥d.

[0011] In one embodiment, the cross-section of the reference plane is at least one of a straight line, an arc line, a plurality of straight lines connected, and a plurality of arc lines connected.

[0012] In one embodiment, the fusion device body includes a solid frame and a porous filling piece, the porous filling piece is filled in the solid frame, and a portion of the porous filling piece is exposed through the solid frame, and the bone grafting hole is opened on the porous filling piece.

[0013] In one embodiment, the solid frame includes a first crossbeam and a second crossbeam that are arranged in a ring shape and spaced apart along the first direction, and a connecting portion, wherein the connecting portion is connected between one end of the first crossbeam and the second crossbeam along a second direction, and the second direction is the width direction or the length direction of the fusion device body, and the porous filling member is filled between the first crossbeam, the second crossbeam and the connecting portion.

[0014] In one embodiment, the porous filling member includes a plurality of single rods connected in a criss-cross pattern, and the single rods at the joints between the porous filling member and the solid frame are embedded in the solid frame.

[0015] In one embodiment, the porous filling member is provided with an annular solid reinforcement member along the opening of the bone graft hole;

[0016] Alternatively, the solid frame is provided with an annular solid reinforcement piece along the opening of the bone graft hole.

[0017] In one embodiment, a serrated protrusion is provided on the abutting surface of the fusion device body for abutting the vertebral body, and the serrated protrusion includes a porous base portion at the root and a top solid portion connected to the porous base portion on the side away from the abutting surface.

[0018] In one embodiment, at least a portion of the abutment surface is filled with a porous filler.

[0019] The above-mentioned intervertebral fusion device includes a fusion device body, and the fusion device body is provided with a bone grafting hole that penetrates along a first direction. The hole wall of the bone grafting hole includes a plurality of convex areas and a plurality of concave areas, the convex areas protrude from the reference plane, the concave areas are recessed in the reference plane, and the sum of the volumes of the first space enclosed by all the convex areas and the reference plane is greater than the sum of the volumes of the second space enclosed by all the concave areas and the reference plane. The intervertebral fusion device with the reference plane as the hole wall of the bone grafting hole is taken as a reference fusion device. It can be understood that, compared with the reference fusion device, in the present application, the convex area will increase the cross-section of the part, thereby increasing the volume of the part; the concave area will reduce the cross-section of the part, thereby reducing the volume of the part. The volume of the first space enclosed by the convex area and the reference plane is the part that increases the volume, and the volume of the second space enclosed by the concave area and the reference plane is the part that decreases the volume. Since the sum of the volumes of the first spaces enclosed by all convex areas and the reference plane is greater than the sum of the volumes of the second spaces enclosed by all concave areas and the reference plane, the overall volume of the bone graft hole is larger than that of the reference fusion device. Therefore, the amount of bone graft material contained therein can be increased, thereby improving the postoperative bonding strength between the intervertebral fusion device and the vertebral body. At the same time, compared with the reference fusion device, the orifice area of ​​the bone graft hole has not increased, so the area of ​​the fusion device body used to contact the vertebral body will not decrease, so that the intervertebral fusion device can be better limited, making it less likely to shift after surgery, thereby improving the position stability of the intervertebral fusion device. In summary, compared with the reference fusion device, the intervertebral fusion device of the present application can increase the volume inside the bone graft hole without increasing the area of ​​the bone graft hole opening, thereby taking into account the larger contact area between the intervertebral fusion device and the vertebral body, as well as the larger bone graft hole volume, so that the intervertebral fusion device has better positional stability after surgery and better bonding strength with the vertebral body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of an intervertebral fusion device in one embodiment of the present application (posterior approach thoracolumbar intervertebral fusion device).

[0021] Figure 2 for Figure 1 A cross-sectional view of the intervertebral fusion cage is shown.

[0022] Figure 3 It is a schematic diagram of the structure of an intervertebral fusion cage in another embodiment of the present application (thoracolumbar intervertebral fusion cage via transforaminal approach).

[0023] Figure 4 for Figure 3 A cross-sectional view of the intervertebral fusion cage is shown.

[0024] Figure 5 It is a schematic diagram of the structure of an intervertebral fusion device in another embodiment of the present application (cervical intervertebral fusion device).

[0025] Figure 6 for Figure 5 A cross-sectional view of the intervertebral fusion cage is shown.

[0026] Figure 7 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in one embodiment of the present application.

[0027] Figure 8 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0028] Fig. 9 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0029] Fig.10 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0030] Fig.11 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0031] Fig.12 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0032] Fig.13 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0033] Fig.14 FIG. 1 is a schematic diagram of the shape of the bone grafting hole of the intervertebral fusion device in another embodiment of the present application.

[0034] Fig.15 Schematic diagram of the structure of the sawtooth protrusion in one embodiment of the present application.

[0035] Fig.16 This is a schematic structural diagram of a sawtooth protrusion in another embodiment of the present application.

[0036] Fig.17 This is a schematic structural diagram of a sawtooth protrusion in another embodiment of the present application.

[0037] Reference numerals:

[0038] The physical frame 100, the first cross beam 110, the second cross beam 120, the connecting portion 130, and the guide head 140;

[0039] The porous filling member 200, the abutting surface 210, the bone graft hole 220, the convex area 221, and the concave area 222;

[0040] Solid reinforcement 300;

[0041] Sawtooth protrusion 400, porous base portion 410, top solid portion 420;

[0042] Reference surface 510 , first space 520 , second space 530 . DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0044] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0045] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0046] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0047] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0048] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0049] See also Figure 1 , Figure 3 , Figure 5 and Figure 7 The intervertebral fusion provided in one embodiment of the present application can be arranged between two vertebrae arranged at intervals along a first direction. The intervertebral fusion device includes a fusion device body, and a bone graft hole 220 passes through the fusion device body along a first direction. The hole wall of the bone graft hole 220 includes a plurality of convex areas 221 and a plurality of concave areas 222. The bone graft hole 220 has a reference plane 510. The convex areas 221 protrude from the reference plane 510, and the concave areas 222 are recessed in the reference plane 510. The sum of the volumes of the first space 520 enclosed by all the convex areas 221 and the reference plane 510 is a, and the sum of the volumes of the second space 530 enclosed by all the concave areas 222 and the reference plane 510 is b, and a>b.

[0050] Specifically, the convex area 221 protrudes from the reference plane 510, which means it protrudes toward the center side of the bone graft hole 220; the concave area 222 is recessed from the reference plane 510, which means it is recessed toward the wall of the bone graft hole 220. The fusion device body has two abutment surfaces 210 arranged opposite to each other along the first direction, and the two abutment surfaces 210 are used to abut against two vertebrae in a one-to-one correspondence. The orifice area of ​​the bone graft hole 220 is the cross-sectional area of ​​the opening of the bone graft hole 220 on the two abutment surfaces 210. In each group of adjacent convex areas 221 and concave areas 222, there is a turning line between the crest of the convex area 221 and the trough of the concave area 222, and the orifice contour line of the bone graft hole 220 and the turning line of each group of adjacent convex areas 221 and concave areas 222 are smoothly connected to form the reference plane 510. The intervertebral fusion cage using the reference plane 510 as the wall of the bone graft hole is used as a reference fusion cage. In the reference fusion cage, the reference plane 510 and the hole contour line of the bone graft hole 220 form a reference bone graft space.

[0051] In the above intervertebral fusion device, compared with the reference bone grafting space of the reference fusion device, in the present application, the convex area 221 will increase the cross section of the part, thereby increasing the volume of the part; the concave area 222 will reduce the cross section of the part, thereby reducing the volume of the part. The volume of the first space 520 surrounded by the convex area 221 and the reference plane 510 is the part that increases the volume, and the volume of the second space 530 surrounded by the concave area 222 and the reference plane 510 is the part that reduces the volume. Since the sum of the volumes of the first space 520 surrounded by all convex areas 221 and the reference plane 510 is greater than the sum of the volumes of the second space 530 surrounded by all concave areas 222 and the reference plane 510, the overall volume of the bone grafting hole 220 is larger than the reference bone grafting space, so the filling amount of the bone grafting material contained therein can be increased, thereby improving the bonding strength between the intervertebral fusion device and the vertebral body after surgery. At the same time, since the reference plane 510 passes through the orifice contour line of the bone graft hole 220 when forming the reference plane 510, that is, the orifice size of the bone graft hole 220 in the present application is equal to that of the reference fusion device, the area on the two abutment surfaces 210 for contacting the vertebral body will not be reduced, so that the intervertebral fusion device can be better limited, so that it is not easy to shift after surgery, and the position stability of the intervertebral fusion device is improved. In summary, compared with the reference fusion device, the intervertebral fusion device of the present application can increase the volume in the bone graft hole 220 without increasing the orifice area of ​​the bone graft hole 220, thereby taking into account the larger contact area between the intervertebral fusion device and the vertebral body, and the larger volume of the bone graft hole 220, so that the intervertebral fusion device has better position stability after surgery, and has better bonding strength with the vertebral body. In addition, the hole wall of the bone graft hole 220 is set to such an uneven shape, which can also increase the bonding strength between the hole wall of the bone graft hole 220 and the implant material, so that the overall strength of the entire intervertebral fusion device is higher, so that the vertebral body can be better supported.

[0052] It should be noted that the intervertebral fusion cage in the embodiment of the present application can be of various types, such as Figure 1 and Figure 2 Posterior thoracolumbar interbody fusion as shown, or Figure 3 and Figure 4 Transforaminal thoracolumbar interbody fusion as shown, or Figure 5 and Figure 6 Cervical interbody fusion cage shown.

[0053] exist Figures 7 to 11 In the illustrated embodiment, the convex regions 221 and the concave regions 222 are alternately distributed along the first direction. Fig.12 In other embodiments, the convex area 221 and the concave area 222 may also be alternately distributed along the circumference of the bone graft hole 220, and connected end to end to form a complete ring. Fig.13 In other embodiments, the convex regions 221 and the concave regions 222 are alternately distributed along the first direction, and at the same time, the convex regions 221 and the concave regions 222 are alternately distributed along the circumference of the bone graft hole 220. Fig.14 In other embodiments, the extension paths of the convex region 221 and the concave region 222 have a component along the first direction and a component along the circumference of the bone graft hole 220. In other embodiments, the distribution of the convex region 221 and the concave region 222 can also be set arbitrarily.

[0054] In some embodiments, on the longitudinal section of the intervertebral fusion cage, the cross-section of the hole wall of the bone graft hole 220 is sinusoidal (eg Figure 7 ), sawtooth wave (e.g. Fig.11 ), rectangular wave, triangular wave, trapezoidal wave (e.g. Fig.10 ), a bell-shaped wave or a truncated sine wave. Alternatively, it may be an irregular arbitrary waveform.

[0055] In the several embodiments of the accompanying drawings, there is only one waveform. In other embodiments, the above waveforms can be combined in any way.

[0056] In several embodiments shown in the drawings, the waveform extends along the first direction. In other embodiments, the waveform may extend along the circumference of the bone graft hole 220 or along the first direction and the circumference of the bone graft hole 220 as mentioned in the above embodiments.

[0057] Among various waveforms, preferably, the shape of the hole wall of the bone graft hole 220 is a smooth transition shape. Usually, when the bone graft material is filled into the bone graft hole 220, the bone graft material is crushed into particles and then inserted into the bone graft hole 220. Compared with the hole wall with sharp corners, the hole wall is set to a smooth shape. When the bone graft material is inserted, the hole wall is not easy to block the particles of the bone graft material, making it easier to fill the bone graft hole 220, so that the amount of bone graft material filled in the bone graft hole 220 is larger and the compactness is higher, thereby further improving the bonding strength between the intervertebral fusion device and the vertebral body after surgery.

[0058] When the hole wall shape of the bone graft hole 220 is a truncated sine wave extending along the first direction, the adjacent convex area 221 and concave area 222 are not directly connected, but there is an intermediate area, and the intermediate area is part of the reference plane 510. This is equivalent to taking a certain section of the reference plane 510 extending along the first direction as the intermediate area, the convex area 221 is connected to one end of the intermediate area, and the concave area 222 is connected to the other end of the intermediate area.

[0059] See also Figure 8 In some embodiments, the cross-sectional area of ​​any point inside the bone graft hole 220 along the first direction is c, the orifice area of ​​the bone graft hole 220 is d, and c≥d.

[0060] Specifically, in Figure 8 In the figure, the reference surface 510 is in an outwardly convex drum shape, and the cross-sectional area of ​​any point inside the bone graft hole 220 is formed to be larger than the orifice area of ​​the bone graft hole 220. In this way, the volume of the bone graft hole 220 can be increased to a greater extent while ensuring that the orifice area of ​​the bone graft hole 220 remains unchanged, thereby further increasing the filling amount of the bone graft material therein, and further improving the bonding strength between the intervertebral fusion device and the vertebral body after surgery.

[0061] Of course, in other embodiments, the bone graft hole 220 is set to Figure 7 or Fig. 9 The shape shown is also possible. Figure 7 In the illustrated embodiment, the reference surface 510 is in a straight cylindrical shape, and the cross-sectional area of ​​a part of the internal region of the bone graft hole 220 formed is larger than the orifice area of ​​the bone graft hole 220, and the cross-sectional area of ​​a part of the internal region is smaller than the orifice area of ​​the bone graft hole 220. Fig. 9 In the embodiment shown, the reference surface 510 is concave, and the cross-sectional area of ​​the part of the internal region of the bone graft hole 220 is larger than the orifice area of ​​the bone graft hole 220, and the cross-sectional area of ​​the part of the internal region is smaller than the orifice area of ​​the bone graft hole 220. Figure 7 The embodiment shown or Fig. 9The embodiments shown must all meet the aforementioned requirement that “the sum of the volumes of the first space 520 enclosed by all convex regions 221 and the reference plane 510 is greater than the sum of the volumes of the second space 530 enclosed by all concave regions 222 and the reference plane 510 ”.

[0062] In some embodiments, the cross-section of the reference plane 510 is in the shape of at least one of a straight line, an arc line, a plurality of straight lines connected, and a plurality of arc lines connected.

[0063] Specifically, in Figure 7 , Fig.10 and Fig.11 In the illustrated embodiment, the cross-section of the reference plane 510 is a straight line, which may extend along the first direction, or may be inclined at an angle to the first direction. Figure 8 and Fig. 9 In the illustrated embodiment, the section line of the reference plane 510 is in an arc shape, and the arc shape can be a regular circular arc shape or a non-circular arc shape. In other embodiments, the section line of the reference plane 510 can also include multiple straight lines, and these straight lines are directly connected in sequence or connected by circular arcs. In other embodiments, the section line of the reference plane 510 can also include segment arc lines, and these arcs are connected in sequence.

[0064] See also Figure 1 , Figure 3 and Figure 5 In some embodiments, the fusion device body includes a solid frame 100 and a porous filling piece 200 , the porous filling piece 200 is filled in the solid frame 100 , and a partial area of ​​the porous filling piece 200 is exposed through the solid frame 100 , and the bone grafting hole 220 is opened on the porous filling piece 200 .

[0065] Specifically, the interior of the solid frame 100 is solid, and the porous filling piece 200 is porous. The solid frame 100 supports the porous filling piece 200, and the porous filling piece 200 is exposed through the solid frame 100, so that the vertebral bodies on both sides of the intervertebral fusion cage can grow to contact with the exposed part of the porous filling piece 200, and grow toward the inside thereof to fill the pores of the porous filling piece 200, thereby fusing the vertebral bodies with the intervertebral fusion cage, making it difficult for the intervertebral fusion cage to shift after surgery, and improving its position stability.

[0066] Preferably, the solid frame 100 and the porous filling piece 200 are integrally formed by 3D printing or the like, so that the two can have a higher bonding strength and better support for the vertebral body. The solid frame 100 and the porous filling piece 200 can be made of materials such as titanium alloy.

[0067] Continue reading Figure 1 , Figure 3 and Figure 5In some embodiments, the solid frame 100 includes a first beam 110 and a second beam 120 that are arranged in a ring shape and spaced apart along a first direction, and a connecting portion 130, wherein the connecting portion 130 is connected between one end of the first beam 110 and the second beam 120 along a second direction, wherein the second direction is the width direction or the length direction of the fusion device body, and the porous filling member 200 is filled between the first beam 110, the second beam 120 and the connecting portion 130.

[0068] Specifically, in Figure 1 and Figure 3 In the embodiment shown, the second direction is the length direction of the fusion device body. Figure 5 In the illustrated embodiment, the second direction is the width direction of the fusion device body. The connecting portion 130 is used to connect with an instrument so as to place the intervertebral fusion device between vertebral bodies through the instrument. The connection method of the connecting portion 130 and the instrument can be selected from any one of the prior art, which will not be described here.

[0069] Preferably, the connecting portion 130 is also a solid component to enhance the connection strength with the instrument, so that shaking is less likely to occur during the movement process of being transported between vertebral bodies by the instrument, and the placement accuracy will be higher.

[0070] The two end faces of the porous filling piece 200 along the first direction are exposed to form the two aforementioned abutment surfaces 210. The first crossbeam 110 and the second crossbeam 120 arranged at intervals, as well as the connecting portion 130, build the skeleton of the intervertebral fusion device. The porous filling piece 200 is filled into the skeleton built by the three, and together with the skeleton, forms a support for the vertebral body. After the vertebral body contacts the two abutment surfaces 210, it will grow toward the inside of the porous filling piece 200 through the abutment surfaces 210, filling the pores of the porous filling piece 200, thereby better combining with the intervertebral fusion device.

[0071] As mentioned above, the connecting portion 130 is connected between the first crossbeam 110 and one end of the second crossbeam 120 along the second direction, and defines that the third direction, the second direction and the first direction are perpendicular to each other. In the embodiment shown in the drawings, both end surfaces of the porous filling member 200 along the third direction are also exposed, so that the mass of the entire intervertebral fusion device can be reduced. Of course, in other embodiments, the two end surfaces of the porous filling member 200 along the third direction can also be wrapped by the solid frame 100 and not exposed.

[0072] See also Figures 1 to 4In these two types of intervertebral fusion devices, the solid frame 100 also includes a guide head 140, which is connected to the first crossbeam 110 and the second crossbeam 120 at one end away from the connecting portion 130. In the direction away from the connecting portion 130, the size of the guide head 140 in the first direction and / or the third direction gradually decreases. When these two types of intervertebral fusion devices are implanted, a spreader is usually not used to spread the vertebral body. Setting the guide head 140 to the above shape can play a role in guiding and spreading the vertebral body during the implantation of the intervertebral fusion device, thereby reducing the difficulty of implantation. Of course, Figure 5 and Figure 6 In the illustrated embodiment, the guide head structure may also be arranged in the same manner as described above.

[0073] In some embodiments, the porous filling member 200 includes a plurality of single rods connected in a criss-cross pattern, and the single rods at the joints between the porous filling member 200 and the solid frame 100 are embedded in the solid frame 100 .

[0074] Specifically, multiple single rods are arranged in a grid shape by 3D printing or other methods, thereby forming pores, so that the porous filling member 200 is porous. At the intersection of the porous filling member 200 and the solid frame 100, the single rod is embedded in the solid frame 100, similar to a "reinforced concrete structure". By embedding, the bonding strength between the porous filling member 200 and the solid frame 100 is higher, and the support for the vertebral body is also better.

[0075] See also Figure 2 , Figure 4 and Figure 6 In some embodiments, the porous filling member 200 is provided with an annular solid reinforcement member 300 along the opening of the bone graft hole 220 ; or, the solid frame 100 is provided with an annular solid reinforcement member 300 along the opening of the bone graft hole 220 .

[0076] Specifically, the solid reinforcement 300 is similar to the solid frame 100 and is solid inside. By setting a solid structure at both end areas of the hole wall of the bone graft hole 220, the hole wall of the bone graft hole 220 can be better supported, so that the shape of the bone graft hole 220 can be better maintained, the overall strength of the intervertebral fusion device will be higher, and it will not be easy to collapse and deform due to the compression of the vertebral body. In some embodiments, the solid reinforcement 300 is not directly connected to the solid frame 100, but is directly formed on the hole wall of the bone graft hole 220 opened on the porous filling member 200. In other embodiments, the solid reinforcement 300 may also be a part of the solid frame 100. For example, a connecting beam is set so that one end of the connecting beam is connected to the solid reinforcement 300, and the other end is connected to the first crossbeam 110 or the second crossbeam 120.

[0077] See also Figure 1 , Figure 3 and Figure 5 ,as well as Fig.15 In some embodiments, a serrated protrusion 400 is connected to the abutting surface 210 of the fusion device body for abutting the vertebral body. The serrated protrusion 400 includes a porous base portion 410 located at the root, and a top solid portion 420 connected to the porous base portion 410 on the side away from the abutting surface 210.

[0078] A serrated protrusion 400 is provided on the abutting surface 210. The serrated protrusion 400 abuts against the vertebral body, which can increase the friction between the two, so that the intervertebral fusion device placed between the vertebral bodies is not easily displaced, and the position stability is better. In this embodiment, the top entity part 420 is solid inside, and the porous base part 410 is porous. Obviously, the solid top entity part 420 has higher strength. By contacting the vertebral body with the solid top entity part 420, the porous base part 410 can be protected to prevent the porous base part 410 from being separated from the joint of the solid frame 100 due to the compression of the vertebral body when the porous base part 410 directly abuts against the vertebral body. Since the top entity part 420 is not easily deformed by the compression of the vertebral body, the vertebral body can be well supported and firmly "pierced" into the vertebral body, thereby improving the position stability of the intervertebral fusion device.

[0079] In the above-mentioned embodiment, it is mentioned that the solid reinforcement member 300 may also be a part of the solid frame 100. In addition to providing a connecting beam, the solid reinforcement member 300 may also be connected to the top solid portion 420 as a whole.

[0080] Preferably, the ratio of the volume of the top solid portion 420 to the volume of the entire sawtooth protrusion 400 is not greater than 0.5.

[0081] See also Figure 1 , Figure 3 and Figure 5 Preferably, in some embodiments, at least a portion of the abutting surface 210 is filled with the porous filler 200 .

[0082] Specifically, the two end surfaces along the first direction of the porous filling member 200 are exposed through the solid frame 100 to form two abutment surfaces 210. The porous base portion 410 in the sawtooth protrusion 400 is connected to the abutment surface 210 of the porous filling member 200. In this way, after the intervertebral fusion device is placed between the two vertebrae, the top solid portion 420 "pierces" the vertebrae to inhibit the displacement of the intervertebral fusion device between the vertebrae. At the same time, the porous abutment surface 210 also abuts against the vertebrae to increase the positional stability of the intervertebral fusion device. Therefore, the positional stability of the intervertebral fusion device can be achieved by the top solid portion 420 and the porous abutment surface 210. Compared with only "piercing" the vertebral body by a solid sawtooth structure to maintain stability, the structure of this embodiment can reduce damage to the vertebral body; compared with only maintaining stability by a porous abutment surface 210, the structure of this embodiment can protect the porous base part 410 by the top solid part 420 to prevent the porous base part 410 from being separated from the joint of the solid frame 100 due to vertebral compression. Compared with abutting the vertebral body by a solid abutment surface 210, the structure of this embodiment can enable the vertebral body to grow and integrate into the pores of the porous structure, thereby further improving the bonding strength between the intervertebral fusion cage and the vertebral body.

[0083] Of course, in other embodiments, the abutting surface 210 may also be formed by the solid frame 100 . Alternatively, the abutting surface 210 may be partially formed by the solid frame 100 and partially formed by the porous filler 200 .

[0084] See also Figure 3 and Figure 5 Preferably, in some embodiments, the plurality of sawtooth protrusions 400 are arranged in a ring shape. It can be understood that when set in this shape, the sawtooth protrusions 400 can inhibit the displacement of the intervertebral fusion cage from multiple directions, further improving its position stability.

[0085] Preferably, each sawtooth protrusion 400 extends in an arc shape, and each radius ranges from 10mm to 50mm. The spacing between two adjacent rows of sawtooth protrusions 400 ranges from 2mm to 10mm. When the protrusions meet the above size requirements, the effect of improving position stability is better.

[0086] See also Figures 15 to 17 In some embodiments, the longitudinal cross-section of the sawtooth protrusion 400 is triangular, arched, or fin-shaped. Of course, other irregular shapes are also possible.

[0087] See also Fig.15 and Fig.16 In some embodiments, the top of the sawtooth protrusion 400 is pointed; or, see Fig.17 In some embodiments, the top of the sawtooth protrusion 400 is rounded.

[0088] See also Fig.15 and Fig.17 In some embodiments, the sawtooth protrusion 400 may protrude vertically from the abutting surface 210 in a direction perpendicular to the abutting surface 210; or, see Fig.16 In some embodiments, the sawtooth protrusion 400 may be inclined and protruded from the abutting surface 210, that is, the protruding direction is not perpendicular to the abutting surface 210. For such an inclined and protruding structure, preferably, the sawtooth protrusion 400 is inclined from the abutting surface 210 toward the side close to the connecting portion 130. It can be understood that when the intervertebral fusion cage is implanted, the area where the connecting portion 130 is located is the last to enter between the vertebral bodies. By making the sawtooth protrusion 400 inclined toward the side close to the connecting portion 130, the scratching damage of the vertebral body by the sawtooth protrusion 400 during the implantation process can be reduced.

[0089] See also Figure 1 In other embodiments, the plurality of sawtooth protrusions 400 may also be arranged linearly at intervals.

[0090] In some embodiments, on the abutting surface 210, the sawtooth protrusions 400 in some areas are linearly spaced, and the multiple sawtooth protrusions 400 in some areas are annularly arranged. Alternatively, the abutting surface 210 is divided into multiple areas, and the multiple sawtooth protrusions 400 in each area are linearly spaced, and the arrangement directions of each area are different.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An intervertebral fusion cage, used to be placed between two vertebrae spaced apart along a first direction, characterized in that: The intervertebral fusion cage comprises: Fusion device body; A bone graft hole (220) passes through the fusion device body along the first direction, and the hole wall of the bone graft hole (220) includes a plurality of convex areas (221) and a plurality of concave areas (222); The bone graft hole (220) has a reference plane (510), the convex area (221) protrudes from the reference plane (510), the concave area (222) is recessed in the reference plane (510), the sum of the volumes of the first space (520) enclosed by all the convex areas (221) and the reference plane (510) is a, and the sum of the volumes of the second space (530) enclosed by all the concave areas (222) and the reference plane (510) is b, and a>b.

2. The intervertebral fusion cage according to claim 1, characterized in that: In the longitudinal section of the intervertebral fusion cage, the hole wall section of the bone graft hole (220) is at least one of a sine wave shape, a sawtooth wave shape, a rectangular wave shape, a triangle wave shape, a trapezoidal wave shape, a bell wave shape or a truncated sine wave shape.

3. The intervertebral fusion cage according to claim 1, characterized in that: The cross-sectional area of ​​any point inside the bone graft hole (220) along the first direction is c, and the opening area of ​​the bone graft hole (220) is d, where c≥d.

4. The intervertebral fusion cage according to claim 1, characterized in that: The cross-section of the reference surface (510) is in the form of at least one of a straight line, an arc line, a plurality of straight lines connected, and a plurality of arc lines connected.

5. The intervertebral fusion cage according to any one of claims 1 to 4, characterized in that: The fusion device body comprises a solid frame (100) and a porous filling piece (200), wherein the porous filling piece (200) is filled in the solid frame (100), and a partial area of ​​the porous filling piece (200) is exposed through the solid frame (100), and the bone grafting hole (220) is opened on the porous filling piece (200).

6. The intervertebral fusion cage according to claim 5, characterized in that: The solid frame (100) comprises a first crossbeam (110) and a second crossbeam (120) which are arranged in a ring shape and spaced apart along the first direction, and a connecting portion (130), wherein the connecting portion (130) is connected between one end of the first crossbeam (110) and the second crossbeam (120) along a second direction, wherein the second direction is a width direction or a length direction of the fusion device body, and the porous filling member (200) is filled between the first crossbeam (110), the second crossbeam (120) and the connecting portion (130).

7. The intervertebral fusion cage according to claim 5, characterized in that: The porous filling member (200) comprises a plurality of single rods connected in a crisscross pattern, and the single rods at the joints between the porous filling member (200) and the solid frame (100) are embedded in the solid frame (100).

8. The intervertebral fusion cage according to claim 5, characterized in that: On the hole wall of the bone graft hole (220), the porous filling member (200) is provided with an annular solid reinforcement member (300) along the hole opening of the bone graft hole (220); Alternatively, the solid frame (100) is provided with an annular solid reinforcement piece (300) along the opening of the bone graft hole (220).

9. The intervertebral fusion cage according to any one of claims 1 to 4, characterized in that: A sawtooth protrusion (400) is provided on the abutting surface of the fusion device body for abutting against the vertebral body. The sawtooth protrusion (400) includes a porous base portion (410) located at the root, and a top solid portion (420) connected to the porous base portion (410) on the side facing away from the abutting surface.

10. The intervertebral fusion cage according to claim 9, characterized in that: At least a portion of the abutment surface is filled with a porous filler (200).

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