Expandable interbody fusion cage

Abstract

The invention discloses an expandable interbody fusion cage. The expandable interbody fusion cage comprises a first main body, a second main body, a first connecting piece and a first adjusting piece, the first main body and the second main body are arranged in the vertical direction and are movably connected through the first connecting piece, and the first main body and the second main body at least have the capability of being separated from each other in the vertical direction under the connecting action of the first connecting piece; the first adjusting part is arranged on the first main body or the second main body, and the first main body and the second main body can be at least separated from each other by controlling the first adjusting part. Compared with the prior art, the fusion cage can be expanded in the vertical direction after being placed in the intervertebral space, on one hand, the fusion cage can abut against a vertebral end plate, improve stability, prevent sliding displacement and improve the fusion rate, and on the other hand, the fusion cage can help the intervertebral space of a lesion section recover to the normal height range, and the treatment effect is enhanced; in addition, the device can be suitable for intervertebral spaces of different heights, special customization is not needed for different lesion segments, and the medical cost is reduced.

Description

Technical Field

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

[0002] Ossification of the Posterior Longitudinal Ligament (OPLL) refers to a disease in which the posterior longitudinal ligament of the cervical spine ossifies, compressing the spinal cord and nerve roots, causing sensory and motor disorders in the limbs and visceral autonomic dysfunction. The treatment of this disease can be divided into conservative treatment and surgical treatment. Anterior Controllable Antedis Placement and Fusion (ACAF) is a new surgical method for treating cervical OPLL in recent years. This procedure achieves the purpose of expanding the spinal canal and decompressing the spinal cord by moving the ossification complex forward as a whole.

[0003] ACAF surgery combines the direct decompression of traditional anterior cervical surgery and the safe operation of posterior cervical surgery, effectively expanding the sagittal diameter and cross-sectional area of ​​the cervical spinal canal, reducing the rate of spinal canal stenosis, and completely decompressing the spinal cord, with good therapeutic effects. However, ACAF surgery still has shortcomings, which are mainly caused by the fusion device, as follows:

[0004] 1. The existing fusion cage cannot adjust its size, and the required size of the fusion cage is usually determined based on the intervertebral height of the diseased segment, which greatly affects the effective intervertebral fusion and weakens the expected therapeutic effect of ACAF surgery;

[0005] 2. Most OPLL patients have lost their cervical curvature. However, the existing fusion devices are not able to restore the curvature of the cervical spine after surgery in order to be suitable for various intervertebral fusion surgeries. Therefore, ACAF surgery can only promote the recovery of the cervical curvature with the help of the holding effect of the pedicle screws, but the effect is not good.

[0006] Therefore, there is an urgent need to design a new fusion device to overcome the difficulties encountered in ACAF surgery. Summary of the invention

[0007] The purpose of the present invention is to provide an expandable intervertebral fusion device which is applied to ACAF surgery, has good stability, high fusion rate, can help the cervical spine restore its curvature, and is flexible and convenient to operate.

[0008] In order to achieve the above-mentioned object, the present invention provides an expandable intervertebral fusion device, which includes a first body, a second body, a first connecting member and a first adjusting member. The first body and the second body are arranged in an up-down direction and are movably connected through the first connecting member, and the first body and the second body have the ability to separate from each other in the up-down direction at least under the connection of the first connecting member. The first adjusting member is provided on the first body or the second body, and by manipulating the first adjusting member, the first body and the second body can at least separate from each other.

[0009] After being placed in the intervertebral space, the fusion device can expand in the vertical direction. On the one hand, it can achieve contact with the vertebral end plate, increase stability, prevent sliding and displacement, and improve the fusion rate. On the other hand, it can help the intervertebral space of the diseased segment to return to the normal height range and enhance the treatment effect. In addition, the ability to expand in the vertical direction allows the fusion device to be suitable for intervertebral spaces of different heights. It does not need to be specially customized for different diseased segments and different patients, which reduces medical costs.

[0010] Furthermore, the first body includes a first inward surface facing the second body and a first outward surface facing away from the second body, and the second body includes a second inward surface facing the first body and a second outward surface facing away from the first body. The first inward surface and the second inward surface are parallel to each other and fit each other when the fusion device is in a contracted state. The first outward surface and the second outward surface are both used to fit the end plate of the vertebral body, but the two are not parallel to each other. In the direction from front to back, the distance between the first outward surface and the second outward surface has a decreasing trend, that is, the first outward surface and the second outward surface gradually approach each other according to a certain change rule. The purpose of such a design is to make the fusion device more adaptable to the cervical intervertebral space that is wide in front and narrow in the back, and can help the cervical spine restore the curvature after implantation. Combined with the holding effect of the pedicle screw, it can provide patients with a more comprehensive and lasting treatment effect, thereby improving the effectiveness of ACAF surgery. In the left and right directions, the distance between the first outward surface and the second outward surface is constant to avoid the adverse consequences such as cervical scoliosis caused by the fusion device after implantation.

[0011] Furthermore, the first outward surface and the second outward surface are both anti-slip surfaces, which are formed by orderly or disorderly arranged anti-slip structures. The anti-slip structures can be in various shapes, such as sharp teeth, cone thorns, particles, etc.

[0012] Preferably, the first main body includes a plurality of first anti-slip structures, which are in the shape of sharp teeth, extend in the left-right direction, and are continuously arranged in the front-to-back direction, and the plane formed by the edges and corners of the first anti-slip structures is the first outward-facing surface. Correspondingly, the second main body includes a plurality of second anti-slip structures, which are also in the shape of sharp teeth, extend in the left-right direction, and are continuously arranged in the front-to-back direction, and the plane formed by the edges and corners of the second anti-slip structures is the second outward-facing surface. When the fusion device is implanted in place, the edges and corners of the first anti-slip structures are pressed against the endplate of the vertebra on one side, that is, the first outward-facing surface is tightly fitted with the endplate of the vertebra on one side; the edges and corners of the second anti-slip structures are pressed against the endplate of the vertebra on the other side, that is, the second outward-facing surface is tightly fitted with the endplate of the vertebra on the other side.

[0013] Furthermore, the first body is provided with a first cavity extending from the first outward surface to the first inward surface, and the second body is provided with a second cavity extending from the second outward surface to the second inward surface. The first cavity is connected to the second cavity, and the two are used to fill the bone graft material after the fusion device is implanted in place. Since the fusion device can expand, it can fill more bone graft material than a fusion device of fixed size, which is conducive to improving the fusion rate. Moreover, since the first cavity extends to the first outward surface and the second cavity extends to the second outward surface, the bone graft material can directly contact the end plate of the vertebral body, further improving the fusion rate.

[0014] Furthermore, the first body is provided with a first hole extending from the first inner surface to the first outer surface in the up-down direction, and the second body is provided with a second hole extending from the second inner surface to the second outer surface in the up-down direction. The first connecting member includes a first rod body, one end of which is inserted into the first hole and the other end is inserted into the second hole. In order to realize that the first body and the second body can be separated from each other under the connecting action of the first connecting member, at least one of the two groups of plug-in fits between the first rod body and the first hole and the second hole is a loose fit, that is, under the action of the first adjusting member, the first rod body can slide axially in the first hole and / or the second hole.

[0015] Preferably, among the two groups of plug-in fits between the first rod body and the first hole and the second hole, one group of plug-in fits is a loose fit, and the other group of plug-in fits is a tight fit, such as an interference fit, a thread fit, etc. In this way, when the first adjusting member is manipulated to separate the first body and the second body from each other, only one of the bodies slides axially relative to the first rod body, and the other body remains stationary relative to the first rod body, so that even in the limited space of the cervical intervertebral space, the sliding body can have a sufficient stroke, so that the first adjusting member has a larger adjustment range of motion, thereby reducing its manipulation difficulty.

[0016] Furthermore, the fusion device provided by the present invention also includes a first elastic member, which cooperates with the first connecting member so that the first body and the second body maintain a tendency to approach each other. When the force of the first adjusting member driving the first body and the second body to separate from each other is withdrawn, the first body and the second body approach each other under the action of the restoring force of the first elastic member until the first inward surface and the second inward surface fit each other. Therefore, by manipulating the first adjusting member, the first body and the second body can not only be separated from each other, but also approach each other, further improving the adjustability and applicability of the fusion device.

[0017] Further, in order to easily describe how the first elastic member cooperates with the first connecting member, this paragraph temporarily records the hole in the first hole and the second hole that cooperates with the first rod body loosely as the movable hole, the ends of the first rod body that cooperate with the movable hole loosely as the movable ends, the main body of the first main body and the second main body with the movable hole as the movable main body, the first inward surface and the second inward surface are uniformly recorded as the inward surface, and the first outward surface and the second outward surface are uniformly recorded as the outward surface. The first elastic member is arranged in the movable hole and sleeved outside the first rod body. Specifically, the movable hole passes from the inward surface of the movable body to its outward surface in the up-down direction, and the inner wall of the movable hole includes a step facing away from its inward surface; the first connecting member also includes a first stop cap, which is arranged at the movable end of the first rod body; the first elastic member is arranged between the step and the first stop cap and is compressed by both.

[0018] Furthermore, the first adjusting member is a rotating member, and the first body and the second body are controlled to separate from each other by rotating the first adjusting member. The technical effects produced by the first adjusting member being arranged on the first body and the second body are the same, so for ease of description, in the following description paragraphs surrounding the first adjusting member, any one of the first body and the second body is temporarily recorded as the force-applying body and the other as the force-receiving body, and the first inward surface and the second inward surface are uniformly recorded as inward surfaces.

[0019] The first adjusting member is provided on the force-applying body. Specifically, the first adjusting member is pivotally connected to the force-applying body and the rotation plane is a vertical plane. The first adjusting member includes a first cam. When the first adjusting member is rotated, the flange of the first cam may protrude from the force-applying body toward the side where the force-receiving body is located and abut against the force-receiving body in certain periods of time. Based on this structure, it is only necessary to rotate the first adjusting member. When the flange of the first cam protrudes from the force-applying body toward the side where the force-receiving body is located, the flange abuts against the force-receiving body and pushes it to separate from the force-applying body, thereby achieving the expansion of the fusion device in the up-and-down directions.

[0020] Furthermore, the force-applying body is provided with a first accommodating cavity, the inner surface of the force-applying body is provided with a first opening communicating with the first accommodating cavity, and the first cam is arranged in the first accommodating cavity. When the first adjusting member is rotated, the flange of the first cam extends out of the first accommodating cavity from the first opening and abuts against the inner surface of the force-receiving body at certain time periods.

[0021] Furthermore, the first adjusting member also includes a first knob portion disposed outside the force-applying body, which is connected to the first cam through a first rotating shaft, and the three are coaxial. The force-applying body is provided with a first axial hole for the first rotating shaft to pass through and to adapt thereto, so as to realize the pivot connection between the first adjusting member and the force-applying body. Based on this structure, the first cam rotates accordingly by simply twisting the first knob portion, and the operation is simple and convenient. In order to ensure that the exterior of the fusion device is flat and free of protrusions, a first sinking groove is provided on the surface of the force-applying body corresponding to the position of the first accommodating cavity, and the first sinking groove is connected to the first accommodating cavity through the first axial hole, and the first knob portion is provided in the first sinking groove, and the thickness of the first knob portion does not exceed the depth of the first sinking groove.

[0022] Furthermore, the first adjusting member is arranged on the front side of the force-applying body, so that when the fusion device is placed in the intervertebral space in an accurate posture, the first knob portion is just facing the medical staff to facilitate their operation.

[0023] Furthermore, a slot for inserting surgical instruments such as a screwdriver is provided on a surface of the first knob portion that is opposite to the force-applying body.

[0024] Furthermore, a groove is provided on the inner surface of the force-bearing body for the flange of the first cam to slide into, and the bottom of the groove is arc-shaped, so that the flange of the first cam can slide in and out smoothly. The presence of the groove makes the contact position between the flange of the first cam and the inner surface of the force-bearing body farther from the force-applying body, thereby allowing the first cam to have a larger size without increasing the maximum distance between the force-applying body and the force-bearing body.

[0025] Furthermore, there is a certain amount of friction between the first adjusting member and the force-applying body, which allows the first adjusting member to rotate smoothly under the action of external force and pushes the force-receiving body to separate from the force-applying body, while ensuring that the first adjusting member remains stationary after the external force is removed, so that the distance between the force-applying body and the force-receiving body remains constant, that is, ensuring that the fusion device can remain stable after expanding to a certain extent in the vertical direction. The friction exists between any one or more of the first cam, the first rotating shaft, and the first knob and the force-applying body.

[0026] Furthermore, the first main body includes a first sub-body and a second sub-body, which are arranged in a left-right orientation and are movably connected by a second connecting member; under the connecting action of the second connecting member, the first sub-body and the second sub-body can keep synchronization when moving in the up-down direction, and the first sub-body and the second sub-body at least have the ability to separate from each other in the left-right direction. Similarly, the second main body includes a third sub-body and a fourth sub-body, which are arranged in a left-right orientation and are movably connected by a third connecting member; under the connecting action of the third connecting member, the third sub-body and the fourth sub-body can keep synchronization when moving in the up-down direction, and the third sub-body and the fourth sub-body at least have the ability to separate from each other in the left-right direction. Before the fusion device is placed in the intervertebral space, the first sub-body and the second sub-body, and the third sub-body and the fourth sub-body should keep in contact with each other or as close to each other as possible.

[0027] Further, according to the left and right directions, the first sub-body and the third sub-body are on the same side, and the second sub-body and the fourth sub-body are on the same side. In order to enable the first sub-body and the third sub-body, the second sub-body and the fourth sub-body to maintain synchronization when moving in the left and right directions, a plurality of first connecting members are provided and divided into two groups, one of which movably connects the first sub-body and the third sub-body, and the other group movably connects the second sub-body and the fourth sub-body.

[0028] Preferably, there are four first connecting members and their horizontal plane projections are evenly distributed at the four corners of the horizontal plane projections of the first body and the second body, that is, the first sub-body and the third sub-body are movably connected through two first connecting members arranged front and back, and the second sub-body and the fourth sub-body are movably connected through two other first connecting members arranged front and back, so as to improve the stability of the fusion device when it expands in the up and down direction. It should be emphasized that within the above disclosed scope, the connection methods of the four first connecting members with the first body and the second body can be all the same, partially the same, or different.

[0029] Furthermore, the expandable intervertebral fusion device provided by the present invention also includes a second adjustment member, which is arranged on the first split, the second split, the third split or the fourth split. By manipulating the second adjustment member, the combination of the first split and the third split and the combination of the second split and the fourth split can at least be separated from each other. In this way, the fusion device can be expanded and enlarged in the left and right directions. On the one hand, this function can increase the contact range between the fusion device and the vertebral end plate, and improve the stability of the fusion device after implantation. On the other hand, it can make the size of the fusion device larger than the aperture of the steel plate and the gap of the posterior longitudinal ligament, so as to prevent the fusion device from escaping from the intervertebral space through the hole and the gap during the operation, thereby reducing the difficulty of the operation.

[0030] Furthermore, the first body and the second body together form a first cavity, and the third body and the fourth body together form a second cavity, so that when the fusion device expands in the left-right direction, the first cavity and the second cavity can be filled with more bone grafting material, which is beneficial to improve the fusion rate.

[0031] Furthermore, the two end faces of the first split body and the two end faces of the second split body are respectively spliced ​​to form a first inward surface and a first outward surface, and the two end faces of the third split body and the two end faces of the fourth split body are respectively spliced ​​to form a second inward surface and a second outward surface.

[0032] Furthermore, the first body includes a third inward surface facing the second body and a third outward surface facing away from the second body, and the second body includes a fourth inward surface facing the first body and a fourth outward surface facing away from the first body. The third body includes a fifth inward surface facing the fourth body and a fifth outward surface facing away from the fourth body, and the fourth body includes a sixth inward surface facing the third body and a sixth outward surface facing away from the third body. The third inward surface and the fourth inward surface are parallel to each other, the fifth inward surface and the sixth inward surface are parallel to each other, and they are in correspondence with each other when the fusion device is in a contracted state; the third outward surface and the fifth outward surface are in the same plane, the fourth outward surface and the sixth outward surface are in the same plane, and the distance between the above two planes has a decreasing trend along the direction from front to back, that is, they gradually approach each other according to a certain change rule.

[0033] Further, the first connecting member, the second connecting member, and the third connecting member are completely identical in structure, function, and working mode. The second connecting member and the third connecting member will be briefly described below, and the relevant principles and effects can be found in the above description of the first connecting member.

[0034] The first split body is provided with a third hole extending from the third inward-facing surface to the third outward-facing surface in the left-right direction, and the second split body is provided with a fourth hole extending from the fourth inward-facing surface to the fourth outward-facing surface in the left-right direction. The second connecting member includes a second rod body, one end of which is inserted into the third hole and the other end is inserted into the fourth hole, wherein at least one group of plug-in fits is a loose fit, that is, under the action of the second adjusting member, the second rod body can slide axially in the third hole and / or the fourth hole. Similarly, the third split body is provided with a fifth hole extending from the fifth inward-facing surface to the fifth outward-facing surface in the left-right direction, and the fourth split body is provided with a sixth hole extending from the sixth inward-facing surface to the sixth outward-facing surface in the left-right direction. The third connecting member includes a third rod body, one end of which is inserted into the fifth hole and the other end is inserted into the sixth hole, wherein at least one group of plug-in fits is a loose fit, that is, under the action of the second adjusting member, the third rod body can slide axially in the fifth hole and / or the sixth hole.

[0035] Furthermore, in order to reduce the difficulty of controlling the second adjusting member, among the two groups of plug-in fits between the second rod body and the third hole and the fourth hole, one group of plug-in fits is a loose fit, and the other group of plug-in fits is a tight fit. Similarly, among the two groups of plug-in fits between the third rod body and the fifth hole and the sixth hole, one group of plug-in fits is a loose fit, and the other group of plug-in fits is a tight fit.

[0036] Preferably, two second connecting members are provided and the two are arranged in a front-to-back direction, and two third connecting members are provided and the two are also arranged in a front-to-back direction, so as to improve the stability of the fusion device when it expands in the left-right direction. It should be emphasized that within the above disclosed scope, the connection method of the second connecting member with the first sub-body and the second sub-body can be completely the same, partially the same, or different. The same is true for the third connecting member.

[0037] Furthermore, the fusion device provided by the present invention also includes a second elastic member and a third elastic member, the second elastic member cooperates with the second connecting member, and the third elastic member cooperates with the third connecting member, so that the combination of the first and third sub-parts and the combination of the second and fourth sub-parts maintain a tendency to approach each other, and when the force of the second adjustment member driving the two combinations to separate from each other is withdrawn, the two combinations approach each other under the action of the restoring force of the second elastic member and the third elastic member until the third inward surface and the fourth inward surface, and the fifth inward surface and the sixth inward surface are all in contact with each other. Thus, by manipulating the second adjustment member, the combination of the first and third sub-parts and the combination of the second and fourth sub-parts can not only be separated from each other, but also approach each other, further improving the adjustability of the fusion device.

[0038] The first elastic member, the second elastic member, and the third elastic member are completely identical in structure, function, and working mode, so the second elastic member and the third elastic member will not be described in detail below. However, it should be noted that the second elastic member and the third elastic member do not necessarily need to exist at the same time, and the presence of any one of them can keep the combination of the first sub-body and the third sub-body and the combination of the second sub-body and the fourth sub-body in a tendency to approach each other.

[0039] Further, the second adjusting member is completely identical to the first adjusting member in structure, function and working mode. The second adjusting member will be briefly described below, and the relevant principles and effects can be found in the above description of the first adjusting member.

[0040] There is no difference in the technical effect produced by the second adjusting member being arranged in any one of the first split body, the second split body, the third split body and the fourth split body. Therefore, for the sake of ease of description, in the following description paragraph surrounding the second adjusting member, any one of the first split body, the second split body, the third split body and the fourth split body will be temporarily recorded as a force-applying split body, among which the one opposite to the force-applying split body on the left and right will be recorded as a force-receiving split body, and the third inward surface, the fourth inward surface, the fifth inward surface and the sixth inward surface will be collectively recorded as inward surfaces.

[0041] The second adjusting member is arranged on the force-applying split body, and includes a second cam, a second knob part and a second rotating shaft, which are coaxial and connected as one body. The force-applying split body is provided with a second accommodating cavity, and a second opening communicating with the second accommodating cavity is arranged on the inner surface of the force-applying split body, and a second sinking groove is arranged on the surface of the force-applying split body corresponding to the position of the second accommodating cavity, and the force-applying split body is provided with a second axial hole communicating with the second accommodating cavity and the second sinking groove. The second cam is arranged in the second accommodating cavity, and the second knob part is arranged in the second sinking groove, and the thickness of the second knob part does not exceed the depth of the second sinking groove, and the second rotating shaft passes through the second axial hole and is adapted thereto, so that the second adjusting member is pivotally connected with the force-applying split body. Based on this structure, the second cam rotates with the second knob part by twisting it, and the flange of the second cam extends out of the second opening from the second accommodating cavity and abuts on the inner surface of the force-bearing split body at certain time periods, pushing the assembly where the force-bearing split body is located to separate from the assembly where the force-applying split body is located, thereby realizing the expansion and expansion of the fusion device in the left and right directions.

[0042] Furthermore, there is a certain amount of friction between the second adjusting member and the force-applying split body, which allows the second adjusting member to rotate smoothly under the action of external force and pushes the assembly where the force-bearing split body is located to separate from the assembly where the force-applying split body is located, while ensuring that the second adjusting member remains stationary after the external force is removed, so that the distance between the assembly where the force-bearing split body is located and the assembly where the force-applying split body is located remains constant, that is, ensuring that the fusion device can remain stable after expanding to a certain extent in the left-right direction. The friction exists between any one or more of the second cam, the second rotating shaft, and the second knob portion and the force-applying split body.

[0043] Furthermore, the second adjusting member is arranged on the front side of the force-applying split body, so that when the fusion device is placed in the intervertebral space in an accurate posture, the second knob part is just facing the medical staff to facilitate their operation.

[0044] Furthermore, a slot for inserting surgical instruments such as a screwdriver is provided on the surface of the second knob portion facing away from the force-applying split body.

[0045] Furthermore, the first adjusting member is arranged on the first split body, and the second adjusting member is arranged on the second split body, that is, the second split body is a force-applying split body, and the first split body is a force-receiving split body.

[0046] Compared with the prior art, the expandable intervertebral fusion cage provided by the present invention has the following beneficial effects:

[0047] Firstly, after being placed in the intervertebral space, the fusion device can expand in the up and down directions, so that on the one hand it can achieve contact with the vertebral end plate, increase stability, prevent sliding and displacement, and improve the fusion rate; on the other hand it can help the intervertebral space of the diseased segment to return to the normal height range and enhance the treatment effect. In addition, it can be applied to intervertebral spaces of different heights, and does not need to be specially customized for different diseased segments and different patients, thereby reducing medical costs.

[0048] Secondly, after being placed in the intervertebral space, the fusion device can also expand in the left and right directions, which can increase the contact range between the fusion device and the vertebral end plate and improve the stability of the fusion device after implantation. On the other hand, it can make the size of the fusion device larger than the hole diameter of the steel plate and the gap of the posterior longitudinal ligament, preventing the fusion device from escaping from the intervertebral space through the hole and gap during the operation, thereby reducing the difficulty of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is one of the three-dimensional views of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0050] Figure 2 The second is a three-dimensional view of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0051] Figure 3 It is a front view of an expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0052] Figure 4 It is a right side view of an expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0053] Figure 5 It is one of the exploded views of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0054] Figure 6 This is the second exploded view of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0055] Figure 7 A three-dimensional diagram of a first main body in a specific embodiment of the present invention;

[0056] Figure 8 A three-dimensional diagram of a second body in a specific embodiment of the present invention;

[0057] Fig. 9 It is the AA view in a specific embodiment of the present invention;

[0058] Fig.10 The third is a three-dimensional view of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0059] Fig.11 This is the third exploded view of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0060] Fig.12 The fourth exploded view of the expandable intervertebral fusion cage in a specific embodiment of the present invention;

[0061] Fig.13 It is a three-dimensional diagram of a combination of the second sub-body and the fourth sub-body in a specific embodiment of the present invention.

[0062] In the figure: 1, first body; 101, first inward surface; 102, first outward surface; 103, first anti-slip structure; 104, first cavity; 105, first hole; 106, first accommodating cavity; 107, first opening; 108, first axial hole; 109, first sink; 1010, step; 11, first split body; 1101, third inward surface; 1102, third outward surface; 1103, third hole; 12, second split body; 1201, fourth inward surface; 1202, fourth outward surface; 1203, fourth hole; 1204, second accommodating cavity; 1205, second opening; 1206, second axial hole; 1207, second sink; 2, second body; 201, second inward surface; 202, second outward surface; 203, second Anti-slip structure; 204, second cavity; 205, second hole; 206, groove; 21, third sub-body; 2101, fifth inward surface; 2102, fifth outward surface; 2103, fifth hole; 22, fourth sub-body; 2201, sixth inward surface; 2202, sixth outward surface; 2203, sixth hole; 3, first connecting member; 31, first rod body; 32, first stop cap; 4, first adjusting member; 41, first cam; 42, first knob portion; 43, first rotating shaft; 5, first elastic member; 6, second connecting member; 61, second rod body; 7, third connecting member; 71, third rod body; 8, second adjusting member; 81, second cam; 82, second knob portion; 83, second rotating shaft; 9, second elastic member; 10, third elastic member. DETAILED DESCRIPTION

[0063] The present invention will be described in more detail below in conjunction with specific embodiments. It should be understood by those skilled in the art that these descriptions merely list some specific embodiments of the present invention and do not limit the present invention and its protection scope in any way.

[0064] In order to easily describe the positional relationship between one component and another component shown in the drawings of the specification, spatially relative terms such as "above", "below", "upper", "lower", "top", "bottom" and similar terms will be used herein. It will be understood that spatially relative terms are intended to cover different orientations of the device in use and operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned upside down, the components described as being "above" the other components are reoriented "below" the other components. Specifically for the present invention, the fusion device is applied to the human body, so it is easy to describe it with reference to the human body parts, the orientation of the head is "above", the orientation of the feet is "below", the direction of the face is "front", and the direction of the back is "back".

[0065] In addition, terms such as "first" and "second" in this document are not intended to emphasize the number, order or importance of the referred parts. Unless otherwise specified, terms such as "installed", "connected" and "connected" in this document should be understood in a broad sense. For example, it can be a fixed connection or an integral connection, or a detachable 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. For those skilled in the art, the specific meaning of the above terms in this document should be understood according to the specific circumstances. In addition, "greater than", "less than", "exceed" and the like in this document are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. "Several" means one or more, and "multiple" means more than two.

[0066] Before describing the specific embodiments of the present invention, this article briefly summarizes the key steps of the ACAF operation: making a surgical incision from the front of the neck; treating the intervertebral space of the diseased segment; making grooves on the left and right sides of the vertebra to be moved forward, and removing the bone in front of the vertebra; cutting the vertebra to be moved forward along the groove on one side; placing a fusion device in the intervertebral space; placing a steel plate in front of the diseased segment and making it cross the vertebra to be moved forward, and fixing the steel plate and the fixed vertebra with screws; cutting the vertebra to be moved forward along the groove on the other side, so that the vertebra to be moved forward is completely separated from the other parts of the vertebra; passing the screw through the hole in the steel plate and screwing it into the vertebra to be moved forward; continuing to turn the screw so that the vertebra to be moved forward is pulled up and gradually approaches the steel plate, so as to achieve the overall advancement of the ossification complex.

[0067] See also Figure 1 and Figure 2 The present embodiment provides an expandable intervertebral fusion device, which includes a first body 1, a second body 2, a first connecting member 3 and a first adjusting member 4. The first body 1 and the second body 2 are arranged in an up-down direction and are movably connected through the first connecting member 3, and the first body 1 and the second body 2 have the ability to separate from each other at least in the up-down direction under the connection of the first connecting member 3. The first adjusting member 4 is provided on the first body 1 or the second body 2, and by manipulating the first adjusting member 4, the first body 1 and the second body 2 can at least separate from each other.

[0068] When the fusion device is used in ACAF surgery, before placing it in the intervertebral space, the first body 1 and the second body 2 are kept in contact with each other or as close to each other as possible; after placing it in the intervertebral space, the first adjustment member 4 is manipulated to gradually separate the first body 1 and the second body 2 from each other until the first body 1 abuts against the end plate of the vertebra on one side and the second body 2 abuts against the end plate of the vertebra on the other side, that is, there is no relative sliding between the fusion device and the vertebral body, and the fusion device is implanted in place.

[0069] Compared with the existing fixed-size fusion device, the fusion device provided in this embodiment can expand and expand in the vertical direction after being placed in the intervertebral space. On the one hand, it can achieve abutment with the vertebral end plate, increase stability, prevent sliding displacement, and improve the fusion rate. On the other hand, it can help the intervertebral space of the diseased segment to return to the normal height range and enhance the treatment effect. In addition, the property of being able to expand and expand in the vertical direction allows the fusion device to be suitable for intervertebral spaces of different heights, and does not need to be specially customized for different diseased segments and different patients, reducing medical costs.

[0070] The specific structures of the first body 1 and the second body 2 will be described below.

[0071] See also Figures 3 to 6 The first body 1 includes a first inward surface 101 facing the second body 2 and a first outward surface 102 facing away from the second body 2, and the second body 2 includes a second inward surface 201 facing the first body 1 and a second outward surface 202 facing away from the first body 1. The first inward surface 101 and the second inward surface 201 are parallel to each other and fit each other when the fusion device is in a contracted state. The first outward surface 102 and the second outward surface 202 are both used to fit the end plate of the vertebral body, but the two are not parallel to each other. Along the direction from front to back, the distance between the first outward surface 102 and the second outward surface 202 has a decreasing trend, that is, the first outward surface 102 and the second outward surface 202 gradually approach each other according to a certain change rule. The purpose of such a design is to make the fusion device more adaptable to the cervical intervertebral space that is wide in front and narrow in the back, and can help the cervical spine restore its curvature after being implanted in place. Combined with the holding effect of the pedicle screw, it can provide patients with a more comprehensive and lasting treatment effect, thereby improving the effectiveness of ACAF surgery. In the left-right direction, the distance between the first outward surface 102 and the second outward surface 202 is constant, so as to avoid adverse consequences such as cervical scoliosis caused by the fusion device after implantation.

[0072] In order to improve the holding force of the fusion cage when it contacts the upper and lower vertebrae and effectively reduce the probability of sliding and displacement, the first outward surface 102 and the second outward surface 202 are both anti-slip surfaces. The anti-slip surface is formed by orderly or disorderly arrangement of anti-slip structures, which can be in various shapes, such as sharp teeth, cone thorns, particles, etc.

[0073] Specifically in this embodiment, Figures 1 to 6As shown, the first body 1 includes a plurality of first anti-slip structures 103, which are in the shape of sharp teeth, extending in the left-right direction, and arranged continuously in the front-back direction. The plane formed by the edges and corners of the first anti-slip structures 103 is the first outward surface 102. Correspondingly, the second body 2 includes a plurality of second anti-slip structures 203, which are also in the shape of sharp teeth, extending in the left-right direction, and arranged continuously in the front-back direction. The plane formed by the edges and corners of the second anti-slip structures 203 is the second outward surface 202. When the fusion device is implanted in place, the edges and corners of the first anti-slip structures 103 are pressed against the end plate of the vertebral body on one side, that is, the first outward surface 102 is closely fitted with the end plate of the vertebral body on one side; the edges and corners of the second anti-slip structures 203 are pressed against the end plate of the vertebral body on the other side, that is, the second outward surface 202 is closely fitted with the end plate of the vertebral body on the other side.

[0074] See also Figure 5 and Figure 6 The first body 1 is provided with a first cavity 104 extending from the first outward surface 102 to the first inward surface 101, and the second body 2 is provided with a second cavity 204 extending from the second outward surface 202 to the second inward surface 201. The first cavity 104 is connected to the second cavity 204, and the two are used to fill the bone graft material after the fusion device is implanted in place. Since the fusion device can expand, it can be filled with more bone graft material compared to a fusion device of fixed size, which is conducive to improving the fusion rate. Moreover, since the first cavity 104 extends to the first outward surface 102 and the second cavity 204 extends to the second outward surface 202, the bone graft material can directly contact the end plate of the vertebral body, further improving the fusion rate.

[0075] Specifically in this embodiment, Figure 5 and Figure 6 As shown, the outer contours of the first body 1 and the second body 2 are both approximately rectangular parallelepiped, and their horizontal plane projections are nearly overlapped, presenting an isosceles trapezoid that is wide in the front and narrow in the back, so that the overall shape of the fusion device is closer to the intervertebral disc and is convenient to be placed in the intervertebral space.

[0076] The following will describe how the first body 1 and the second body 2 are movably connected via the first connecting member 3 .

[0077] See also Figure 5 and Figure 6The first body 1 is provided with a first hole 105 extending from the first inward surface 101 to the first outward surface 102 in the up-down direction, and the second body 2 is provided with a second hole 205 extending from the second inward surface 201 to the second outward surface 202 in the up-down direction. The first connecting member 3 includes a first rod 31, one end of which is inserted into the first hole 105 and the other end is inserted into the second hole 205. In order to realize that the first body 1 and the second body 2 can be separated from each other under the connecting action of the first connecting member 3, at least one of the two groups of plug-in fits between the first rod 31 and the first hole 105 and the second hole 205 is a loose fit, that is, under the action of the first adjusting member 4, the first rod 31 can slide axially in the first hole 105 and / or the second hole 205.

[0078] The positive effect brought by the relative sliding of the first main body 1 and the second main body 2 with the first rod body 31 is that the speed of separation of the first main body 1 and the second main body 2 can be increased, so that the fusion device can expand and expand faster in the up-down direction, but the negative effect brought at the same time is that the stroke of separation of the first main body 1 and the second main body 2 can be shortened, resulting in a smaller adjustment range of the first adjusting member 4. Since the cervical intervertebral space is generally narrow, the space allowing the fusion device to expand and expand in the up-down direction is very limited. Therefore, if the first main body 1 and the second main body 2 can both slide relative to the first rod body 31, the adjustment range of the first adjusting member 4 will be extremely small, and the limit position will be reached with a slight movement, which is difficult to control. In view of this, in the two groups of plug-in fits between the first rod body 31 and the first hole 105 and the second hole 205, one group of plug-in fits is a loose fit, and the other group of plug-in fits is a tight fit, such as an interference fit, a thread fit, etc. In this way, when the first adjusting member 4 is operated to separate the first main body 1 and the second main body 2 from each other, only one of the main bodies slides axially relative to the first rod body 31, and the other main body remains stationary relative to the first rod body 31. Therefore, even in the limited space of the cervical intervertebral space, the sliding main body can have sufficient travel, so that the first adjusting member 4 has a larger adjustment range, thereby reducing its operation difficulty.

[0079] Based on the loose fit of the first rod body 31 and the first hole 105 and / or the second hole 205, the fusion device provided in this embodiment also includes a first elastic member 5, which cooperates with the first connecting member 3 so that the first body 1 and the second body 2 maintain a trend of approaching each other. When the force of the first adjusting member 4 driving the first body 1 and the second body 2 to separate from each other is withdrawn, the first body 1 and the second body 2 approach each other under the action of the restoring force of the first elastic member 5 until the first inward surface 101 and the second inward surface 201 fit each other. Thus, by manipulating the first adjusting member 4, the first body 1 and the second body 2 can not only be separated from each other, but also approach each other, further improving the adjustability and applicability of the fusion device.

[0080] In order to facilitate the description of how the first elastic member 5 cooperates with the first connecting member 3, this paragraph temporarily refers to the holes in the first hole 105 and the second hole 205 that are loosely matched with the first rod body 31 as movable holes, the ends of the first rod body 31 that are loosely matched with the movable holes as movable ends, the main bodies with movable holes in the first body 1 and the second body 2 as movable bodies, the first inward surface 101 and the second inward surface 201 are uniformly referred to as inward surfaces, and the first outward surface 102 and the second outward surface 202 are uniformly referred to as outward surfaces. Figure 5 , Figure 6 and Fig. 9 , the first elastic member 5 is arranged in the movable hole and sleeved outside the first rod body 31. Specifically, the movable hole penetrates from the inner surface of the movable body to its outer surface along the up-down direction, and the inner wall of the movable hole includes a step 1010 facing away from its inner surface; the first connecting member 3 also includes a first stop cap 32, which is arranged at the movable end of the first rod body 31; the first elastic member 5 is arranged between the step 1010 and the first stop cap 32 and is compressed by both.

[0081] Specifically in this embodiment, Figure 5 , Figure 6 and Fig. 9 As shown, the first body 1 is a movable body, the first hole 105 is a movable hole, the first hole 105 passes from the first inward surface 101 to the first outward surface 102 along the up-down direction, and the inner wall of the first hole 105 includes a step 1010 facing away from the first inward surface 101; the first rod body 31 is loosely matched with the first hole 105, and the first stop cap 32 is arranged at one end of the first rod body 31 inserted into the first hole 105; the first elastic member 5 is arranged in the first hole 105 and sleeved outside the first rod body 31, one end of the first elastic member 5 abuts against the step 1010, and the other end abuts against the first stop cap 32, thereby being compressed. The first rod body 31 is tightly matched with the second hole 205. Further, the first elastic member 5 is a spring, and the first connecting member 3 is a bolt.

[0082] The specific structure of the first adjusting member 4 and how it drives the first body 1 and the second body 2 to separate from each other will be described below.

[0083] The first adjusting member 4 is a rotating member, which is rotated to control the separation of the first body 1 and the second body 2. The technical effects produced by the first adjusting member 4 being arranged on the first body 1 and the second body 2 are the same, so for ease of description, in the following description paragraphs around the first adjusting member 4, any one of the first body 1 and the second body 2 is temporarily recorded as a force-applying body and the other as a force-receiving body, and the first inward surface 101 and the second inward surface 201 are uniformly recorded as inward surfaces.

[0084] See also Figures 4 to 8, the first adjusting member 4 is arranged on the force-applying body. Specifically, the first adjusting member 4 is pivotally connected to the force-applying body and the rotation plane is a vertical plane. It includes a first cam 41. When the first adjusting member 4 is rotated, the flange of the first cam 41 may protrude from the force-applying body toward the side where the force-receiving body is located and abut against the force-receiving body in certain periods of time. Based on this structure, it is only necessary to rotate the first adjusting member 4. When the flange of the first cam 41 protrudes from the force-applying body toward the side where the force-receiving body is located, the flange abuts against the force-receiving body and pushes it to separate from the force-applying body, thereby realizing the expansion and enlargement of the fusion device in the up-down direction.

[0085] In order to ensure that the flange of the first cam 41 can completely abut against the force-bearing body, the force-applying body is provided with a first accommodating cavity 106, and the inner surface of the force-applying body is provided with a first opening 107 communicating with the first accommodating cavity 106, and the first cam 41 is arranged in the first accommodating cavity 106. When the first adjusting member 4 is rotated, the flange of the first cam 41 extends out of the first accommodating cavity 106 from the first opening 107 and abuts against the inner surface of the force-bearing body at certain periods of time.

[0086] In order to control the first cam 41 hidden inside the force-applying body, the first adjusting member 4 also includes a first knob portion 42 disposed outside the force-applying body, which is connected to the first cam 41 through a first shaft 43, and the three are coaxial. The force-applying body is provided with a first axial hole 108 for the first shaft 43 to pass through and adapt thereto, so as to realize the pivot connection between the first adjusting member 4 and the force-applying body. Based on this structure, the first cam 41 rotates accordingly by simply twisting the first knob portion 42, and the operation is simple and convenient. In order to ensure that the outside of the fusion device is flat and has no protrusions, a first sinking groove 109 is provided on the surface of the force-applying body corresponding to the position of the first accommodating cavity 106, and the first sinking groove 109 is connected to the first accommodating cavity 106 through the first shaft hole 108, and the first knob portion 42 is provided in the first sinking groove 109, and the thickness of the first knob portion 42 does not exceed the depth of the first sinking groove 109.

[0087] The first adjusting member 4 is arranged on the front of the force-applying body, so that when the fusion device is placed in the intervertebral space in an accurate posture, the first knob portion 42 is just facing the medical staff for easy operation. Furthermore, the surface of the first knob portion 42 facing away from the force-applying body is provided with a slot for inserting surgical instruments such as a screwdriver.

[0088] It can be seen from the above structure that under the action of the first adjusting member 4, the maximum distance between the force-applying body and the force-receiving body is determined by the maximum radial direction of the first cam 41. Since the intervertebral space of the cervical vertebrae is generally narrow, the space for the fusion device to expand in the up and down directions is very limited, so the maximum radial direction of the first cam 41 cannot be too large. However, the maximum radial direction of the first cam 41 cannot be too small. The small-sized cam is not strong enough to push the force-receiving body and the force-applying body to separate, and it is also easy to deform or even damage. In view of this, a groove 206 for the flange of the first cam 41 to slide into is provided on the inner surface of the force-receiving body, and the bottom of the groove 206 is arc-shaped, so that the flange of the first cam 41 can slide in and out smoothly. The presence of the groove 206 makes the contact position between the flange of the first cam 41 and the inner surface of the force-receiving body farther away from the force-applying body, thereby allowing the first cam 41 to have a larger size without increasing the maximum distance between the force-applying body and the force-receiving body.

[0089] It should be emphasized that there is a certain amount of friction between the first adjusting member 4 and the force-applying body, which allows the first adjusting member 4 to rotate smoothly under the action of external force and push the force-receiving body and the force-applying body to separate, and at the same time ensures that the first adjusting member 4 remains stationary after the external force is removed, so that the distance between the force-applying body and the force-receiving body remains constant, that is, ensures that the fusion device can remain stable after expanding to a certain extent in the vertical direction. The friction exists between any one or more of the first cam 41, the first rotating shaft 43, and the first knob portion 42 and the force-applying body.

[0090] Specifically in this embodiment, Figures 4 to 8 As shown, the first body 1 is a force-applying body, that is, the first adjusting member 4 is disposed on the first body 1, and the first body 1 is provided with a first accommodating cavity 106, a first opening 107, a first axial hole 108 and a first sink 109. The second body 2 is a force-receiving body, and is provided with a groove 206 accordingly.

[0091] The expandable intervertebral fusion cage provided in this embodiment can expand and enlarge not only in the up-down direction but also in the left-right direction. How to achieve this will be described below.

[0092] See also Figures 10 to 13The first main body 1 includes a first sub-body 11 and a second sub-body 12, which are arranged in a left-right orientation and are movably connected by a second connecting member 6; under the connecting action of the second connecting member 6, the first sub-body 11 and the second sub-body 12 can keep synchronization when moving in the up-down direction, and the first sub-body 11 and the second sub-body 12 at least have the ability to separate from each other in the left-right direction. Similarly, the second main body 2 includes a third sub-body 21 and a fourth sub-body 22, which are arranged in a left-right orientation and are movably connected by a third connecting member 7; under the connecting action of the third connecting member 7, the third sub-body 21 and the fourth sub-body 22 can keep synchronization when moving in the up-down direction, and the third sub-body 21 and the fourth sub-body 22 at least have the ability to separate from each other in the left-right direction. Before the fusion device is placed in the intervertebral space, the first sub-body 11 and the second sub-body 12, and the third sub-body 21 and the fourth sub-body 22 should keep in contact with each other or as close to each other as possible.

[0093] See also Figures 10 to 13 , divided by the left and right directions, the first sub-body 11 and the third sub-body 21 are on the same side, and the second sub-body 12 and the fourth sub-body 22 are on the same side. In order to keep the first sub-body 11 and the third sub-body 21, the second sub-body 12 and the fourth sub-body 22 synchronized when moving in the left and right directions, the first connecting member 3 is provided in plurality and is divided into two groups, one of which flexibly connects the first sub-body 11 and the third sub-body 21, and the other flexibly connects the second sub-body 12 and the fourth sub-body 22.

[0094] Specifically in this embodiment, Figures 10 to 13 As shown, there are four first connecting members 3 and their horizontal plane projections are evenly distributed at the four corners of the horizontal plane projections of the first body 1 and the second body 2, that is, the first sub-body 11 and the third sub-body 21 are movably connected through two first connecting members 3 arranged front and back, and the second sub-body 12 and the fourth sub-body 22 are movably connected through two other first connecting members 3 arranged front and back, so as to improve the stability of the fusion device when it expands in the up and down direction. It should be emphasized that within the above disclosed scope, the connection methods of the four first connecting members 3 and the first body 1 and the second body 2 can be all the same, partially the same, or different.

[0095] See also Figures 10 to 13The expandable intervertebral fusion device provided in this embodiment also includes a second adjustment member 8, which is arranged on the first sub-body 11, the second sub-body 12, the third sub-body 21 or the fourth sub-body 22. By manipulating the second adjustment member 8, the combination of the first sub-body 11 and the third sub-body 21 and the combination of the second sub-body 12 and the fourth sub-body 22 can at least be separated from each other. In this way, the fusion device can be expanded and enlarged in the left and right directions. On the one hand, this function can increase the contact range between the fusion device and the vertebral end plate and improve the stability of the fusion device after implantation. On the other hand, it can make the size of the fusion device larger than the aperture of the steel plate and the gap of the posterior longitudinal ligament, thereby preventing the fusion device from escaping from the intervertebral space through the hole and the gap during the operation, thereby reducing the difficulty of the operation.

[0096] See also Figures 10 to 13 The first sub-body 11 and the second sub-body 12 are combined to form a first cavity 104, and the third sub-body 21 and the fourth sub-body 22 are combined to form a second cavity 204, so that when the fusion device expands in the left-right direction, the first cavity 104 and the second cavity 204 can be filled with more bone grafting materials, which is conducive to improving the fusion rate. Further, the two end surfaces of the first sub-body 11 facing each other up and down and the two end surfaces of the second sub-body 12 facing each other up and down are respectively spliced ​​to form a first inward surface 101 and a first outward surface 102, and the two end surfaces of the third sub-body 21 facing each other up and down and the two end surfaces of the fourth sub-body 22 facing each other up and down are respectively spliced ​​to form a second inward surface 201 and a second outward surface 202.

[0097] See also Figures 10 to 13 The first body 11 includes a third inward surface 1101 facing the second body 12 and a third outward surface 1102 facing away from the second body 12. The second body 12 includes a fourth inward surface 1201 facing the first body 11 and a fourth outward surface 1202 facing away from the first body 11. The third body 21 includes a fifth inward surface 2101 facing the fourth body 22 and a fifth outward surface 2102 facing away from the fourth body 22. The fourth body 22 includes a sixth inward surface 2201 facing the third body 21 and a sixth outward surface 2202 facing away from the third body 21. Among them, the third inward surface 1101 and the fourth inward surface 1201 are parallel to each other, the fifth inward surface 2101 and the sixth inward surface 2201 are parallel to each other, and they are in correspondence with each other when the fusion device is in a contracted state; the third outward surface 1102 and the fifth outward surface 2102 are in the same plane, and the fourth outward surface 1202 and the sixth outward surface 2202 are in the same plane. Along the direction from front to back, the distance between the above two planes has a decreasing trend, that is, they gradually approach each other according to a certain change rule.

[0098] Specifically in this embodiment, Figures 10 to 13As shown, the first sub-body 11 and the second sub-body 12 have the same shape and volume, and are symmetrically arranged about the vertical front and rear plane. Similarly, the third sub-body 21 and the fourth sub-body 22 have the same shape and volume, and are symmetrically arranged about the vertical front and rear plane.

[0099] The first connecting member 3, the second connecting member 6 and the third connecting member 7 are completely identical in structure, function and working mode. The second connecting member 6 and the third connecting member 7 will be briefly described below. For related principles and effects, please refer to the previous description of the first connecting member 3.

[0100] See also Figures 10 to 13 The first body 11 is provided with a third hole 1103 extending from the third inward surface 1101 to the third outward surface 1102 in the left-right direction, and the second body 12 is provided with a fourth hole 1203 extending from the fourth inward surface 1201 to the fourth outward surface 1202 in the left-right direction. The second connecting member 6 includes a second rod 61, one end of which is inserted into the third hole 1103 and the other end is inserted into the fourth hole 1203, wherein at least one set of plug-in fit is a loose fit, that is, under the action of the second adjusting member 8, the second rod 61 can slide axially in the third hole 1103 and / or the fourth hole 1203. Similarly, the third body 21 is provided with a fifth hole 2103 extending from the fifth inward surface 2101 to the fifth outward surface 2102 in the left-right direction, and the fourth body 22 is provided with a sixth hole 2203 extending from the sixth inward surface 2201 to the sixth outward surface 2202 in the left-right direction. The third connecting member 7 includes a third rod body 71, one end of which is inserted into the fifth hole 2103 and the other end is inserted into the sixth hole 2203, wherein at least one set of plug-in fits is a loose fit, that is, under the action of the second adjusting member 8, the third rod body 71 can slide axially in the fifth hole 2103 and / or the sixth hole 2203.

[0101] Further, in order to reduce the difficulty of controlling the second adjusting member 8, one of the two groups of plug-in matches between the second rod body 61 and the third hole 1103 and the fourth hole 1203 is a loose fit, and the other group of plug-in matches is a tight fit. Similarly, one of the two groups of plug-in matches between the third rod body 71 and the fifth hole 2103 and the sixth hole 2203 is a loose fit, and the other group of plug-in matches is a tight fit.

[0102] Specifically in this embodiment, Figures 10 to 13 As shown, two second connecting members 6 are provided and the two are arranged in a front-to-back direction, and two third connecting members 7 are provided and the two are also arranged in a front-to-back direction, so as to improve the stability of the fusion device when it expands in the left-right direction. It should be emphasized that within the above disclosed scope, the connection method of the second connecting member 6 with the first sub-body 11 and the second sub-body 12 can be completely the same, partially the same, or different. The same is true for the third connecting member 7.

[0103] See also Fig.11 and Fig.12 The fusion device provided in this embodiment also includes a second elastic member 9 and a third elastic member 10. The second elastic member 9 cooperates with the second connecting member 6, and the third elastic member 10 cooperates with the third connecting member 7, so that the combination of the first sub-body 11 and the third sub-body 21 and the combination of the second sub-body 12 and the fourth sub-body 22 maintain a tendency to approach each other. When the force of the second adjusting member 8 driving the two combinations to separate from each other is withdrawn, the two combinations approach each other under the action of the restoring force of the second elastic member 9 and the third elastic member 10 until the third inward surface 1101 and the fourth inward surface 1201, and the fifth inward surface 2101 and the sixth inward surface 2201 are all in contact with each other. Therefore, by manipulating the second adjusting member 8, the combination of the first sub-body 11 and the third sub-body 21 and the combination of the second sub-body 12 and the fourth sub-body 22 can not only be separated from each other, but also approach each other, further improving the adjustability of the fusion device.

[0104] The first elastic member 5, the second elastic member 9, and the third elastic member 10 are completely identical in structure, function, and working mode, so the second elastic member 9 and the third elastic member 10 will not be described in detail below. However, it should be pointed out that the second elastic member 9 and the third elastic member 10 do not have to exist at the same time, and the existence of any one of them can keep the combination of the first sub-body 11 and the third sub-body 21 and the combination of the second sub-body 12 and the fourth sub-body 22 close to each other.

[0105] Specifically in this embodiment, the second connecting member 6 and the third connecting member 7 are both bolts, and the second elastic member 9 and the third elastic member 10 are both springs.

[0106] The second adjusting member 8 is completely identical to the first adjusting member 4 in structure, function and working mode. The second adjusting member 8 will be briefly described below. For relevant principles and effects, please refer to the above description of the first adjusting member 4.

[0107] There is no difference in the technical effect produced by the second adjusting member 8 being arranged on any one of the first split body 11, the second split body 12, the third split body 21 and the fourth split body 22. Therefore, for the sake of ease of description, in the following description paragraph surrounding the second adjusting member 8, any one of the first split body 11, the second split body 12, the third split body 21 and the fourth split body 22 will be temporarily recorded as a force-applying split body, among which the one opposite to the force-applying split body on the left and right will be recorded as a force-receiving split body, and the third inward surface 1101, the fourth inward surface 1201, the fifth inward surface 2101 and the sixth inward surface 2201 will be collectively recorded as inward surfaces.

[0108] See also Figures 10 to 13The second adjusting member 8 is provided in the force-applying split body, and includes a second cam 81, a second knob portion 82 and a second rotating shaft 83, which are coaxial and connected as one body. The force-applying split body is provided with a second accommodating cavity 1204, and a second opening 1205 communicating with the second accommodating cavity 1204 is provided on the inner surface of the force-applying split body, and a second sinking groove 1207 is provided on the surface of the force-applying split body at a position corresponding to the second accommodating cavity 1204, and the force-applying split body is provided with a second shaft hole 1206 communicating with the second accommodating cavity 1204 and the second sinking groove 1207. The second cam 81 is provided in the second accommodating cavity 1204, and the second knob portion 82 is provided in the second sinking groove 1207, and the thickness of the second knob portion 82 does not exceed the depth of the second sinking groove 1207, and the second rotating shaft 83 passes through the second shaft hole 1206 and is adapted thereto, so that the second adjusting member 8 is pivotally connected to the force-applying split body. Based on this structure, the second cam 81 rotates accordingly by simply turning the second knob portion 82. The flange of the second cam 81 extends out of the second opening 1205 from the second accommodating cavity 1204 at certain times and abuts against the inner surface of the force-bearing separate body, pushing the assembly where the force-applying separate body is located to separate from the assembly where the force-applying separate body is located, thereby achieving expansion of the fusion device in the left-right direction.

[0109] It should be emphasized that there is a certain amount of friction between the second adjusting member 8 and the force-applying split body, which allows the second adjusting member 8 to rotate smoothly under the action of external force and pushes the assembly where the force-bearing split body is located to separate from the assembly where the force-applying split body is located, while ensuring that the second adjusting member 8 remains stationary after the external force is removed, so that the distance between the assembly where the force-bearing split body is located and the assembly where the force-applying split body is located remains constant, that is, ensuring that the fusion device can remain stable after expanding to a certain extent in the left-right direction. The friction exists between any one or more of the second cam 81, the second rotating shaft 83, and the second knob portion 82 and the force-applying split body.

[0110] The second adjusting member 8 is arranged on the front of the force-applying body, so that when the fusion device is placed in the intervertebral space in an accurate posture, the second knob portion 82 is just facing the medical staff for easy operation. Furthermore, the surface of the second knob portion 82 facing away from the force-applying body is provided with a slot for inserting surgical instruments such as a screwdriver.

[0111] Whether the first adjusting member 4 and the second adjusting member 8 are arranged in the same body does not affect the realization of the functions of the two members. However, since the fusion device is small in size, if the first adjusting member 4 and the second adjusting member 8 are arranged in the same body, it is difficult to arrange and manufacture, and it is too crowded and not conducive to operation. Therefore, the first adjusting member 4 and the second adjusting member 8 are arranged in different bodies.

[0112] Specifically in this embodiment, Figures 10 to 13As shown, the first adjusting member 4 is provided on the first split body 11, and the second adjusting member 8 is provided on the second split body 12, that is, the second split body 12 is a force-applying split body, and the first split body 11 is a force-receiving split body. Accordingly, the first split body 11 is provided with a first accommodating cavity 106, a first opening 107, a first shaft hole 108, and a first sinking groove 109, and the second split body 12 is provided with a second accommodating cavity 1204, a second opening 1205, a second shaft hole 1206, and a second sinking groove 1207.

[0113] The above description is only used to exemplify the present invention and is not used to limit the present invention. It should be pointed out that for ordinary technicians in this field, several improvements, modifications and variations can be made to the present invention, but these improvements, modifications and variations should be regarded as falling within the scope of protection of the present invention without departing from the spirit of the present invention.

Claims

1. An expandable intervertebral fusion cage, characterized in that: The device comprises a first body, a second body, a first connecting member and a first adjusting member; the first body and the second body are arranged in an up-down direction and are movably connected through the first connecting member, and the first body and the second body are at least capable of being separated from each other in the up-down direction under the connection of the first connecting member; the first adjusting member is provided on the first body or the second body, and the first body and the second body can at least be separated from each other by operating the first adjusting member; The first body includes a first inward surface facing the second body and a first outward surface facing away from the second body, and the second body includes a second inward surface facing the first body and a second outward surface facing away from the first body; the first inward surface and the second inward surface fit each other when the fusion device is in a contracted state; the first outward surface and the second outward surface are both used to fit with the vertebral end plate, and the distance between the first outward surface and the second outward surface tends to decrease along the front-to-back direction.

2. The expandable intervertebral fusion cage according to claim 1, characterized in that: The first main body is provided with a first hole extending from the first inner surface to the first outer surface along the up-down direction, and the second main body is provided with a second hole extending from the second inner surface to the second outer surface along the up-down direction; the first connecting member includes a first rod body, one end of which is inserted into the first hole and the other end is inserted into the second hole, and at least one of the two groups of plug-in fits is a loose fit.

3. The expandable intervertebral fusion cage according to claim 2, characterized in that: Among the two groups of plug-in fits between the first rod body and the first hole and the second hole, one group of plug-in fits is a loose fit, and the other group of plug-in fits is a tight fit.

4. The expandable intervertebral fusion cage according to claim 2, characterized in that: It also includes a first elastic member, which cooperates with the first connecting member to keep the first body and the second body close to each other; The hole in the first hole and the second hole that is loosely matched with the first rod body is recorded as a movable hole, the end portions of the two ends of the first rod body that are loosely matched with the movable hole are recorded as movable ends, the main body provided with the movable hole in the first body and the second body is recorded as a movable body, the first inward surface and the second inward surface are uniformly recorded as inward surfaces, and the first outward surface and the second outward surface are uniformly recorded as outward surfaces; The first elastic member is arranged in the movable hole and is sleeved on the outside of the first rod body; the movable hole passes through from the inner surface of the movable body to its outer surface along the up and down directions, and the inner wall of the movable hole includes a step facing away from its inner surface; the first connecting member also includes a first stop cap, which is arranged at the movable end of the first rod body; the first elastic member is arranged between the step and the first stop cap and is compressed by both.

5. The expandable intervertebral fusion cage according to claim 1, characterized in that: Any one of the first body and the second body is recorded as a force-applying body, and the other is recorded as a force-receiving body, and the first inward surface and the second inward surface are collectively recorded as inward surfaces; The first adjusting member is a rotating member, which is pivotally connected to the force-applying body and the rotating plane is a vertical plane; the first adjusting member includes a first cam, a first rotating shaft and a first knob portion, which are coaxial and connected as a whole; The force-applying body is provided with a first accommodating cavity, an inner surface of the force-applying body is provided with a first opening communicating with the first accommodating cavity, and the first cam is arranged in the first accommodating cavity; The force-applying body is provided with a first shaft hole, and the first rotating shaft passes through the first shaft hole and is adapted thereto; A first recessed groove is provided on the surface of the force-applying body at a position corresponding to the first accommodating cavity, and the first recessed groove is connected to the first accommodating cavity through the first shaft hole; the first knob portion is provided in the first recessed groove, and the thickness of the first knob portion does not exceed the depth of the first recessed groove; When the first knob is turned to rotate the first cam, the flange of the first cam extends out of the first accommodating cavity from the first opening at certain times and abuts against the inner surface of the force-bearing body to push the force-bearing body to separate from the force-applying body.

6. The expandable intervertebral fusion cage according to claim 5, characterized in that: A groove for the flange of the first cam to slide into is provided on the inner surface of the force-bearing body, and the bottom of the groove is arc-shaped.

7. The expandable intervertebral fusion cage according to claim 1, characterized in that: The first main body includes a first sub-body and a second sub-body, which are arranged in a left-right direction and movably connected by a second connecting member; under the connecting action of the second connecting member, the first sub-body and the second sub-body can keep synchronization when moving in the up-down direction, and the first sub-body and the second sub-body have the ability to separate from each other at least in the left-right direction; The second main body includes a third sub-body and a fourth sub-body, which are arranged in a left-right direction and movably connected by a third connecting member; under the connecting action of the third connecting member, the third sub-body and the fourth sub-body can keep synchronization when moving in the up-down direction, and the third sub-body and the fourth sub-body have the ability to separate from each other at least in the left-right direction; According to the left and right directions, the first sub-body and the third sub-body are on the same side, and the second sub-body and the fourth sub-body are on the same side; The first connecting members are provided in plurality and are divided into two groups, one group movably connects the first split body with the third split body, and the other group movably connects the second split body with the fourth split body; The fusion device also includes a second adjustment member, which is arranged on the first sub-body, the second sub-body, the third sub-body or the fourth sub-body. By manipulating the second adjustment member, the combination of the first sub-body and the third sub-body and the combination of the second sub-body and the fourth sub-body can at least be separated from each other.

8. The expandable intervertebral fusion cage according to claim 7, characterized in that: The first split body includes a third inward surface facing the second split body and a third outward surface facing away from the second split body, and the second split body includes a fourth inward surface facing the first split body and a fourth outward surface facing away from the first split body; The first split body is provided with a third hole extending from the third inner surface to the third outer surface along the left-right direction, and the second split body is provided with a fourth hole extending from the fourth inner surface to the fourth outer surface along the left-right direction; the second connecting member includes a second rod body, one end of which is inserted into the third hole and the other end is inserted into the fourth hole, and at least one of the two sets of plug-in fits is a loose fit; The third body comprises a fifth inward-facing surface facing the fourth body and a fifth outward-facing surface facing away from the fourth body, and the fourth body comprises a sixth inward-facing surface facing the third body and a sixth outward-facing surface facing away from the third body; The third split body is provided with a fifth hole extending from the fifth inner surface to the fifth outer surface along the left-right direction, and the fourth split body is provided with a sixth hole extending from the sixth inner surface to the sixth outer surface along the left-right direction; the third connecting member includes a third rod body, one end of which is inserted into the fifth hole and the other end is inserted into the sixth hole, and at least one of the two groups of plug-in fits is a loose fit.

9. The expandable intervertebral fusion cage according to claim 7, characterized in that: It also includes a second elastic member, which cooperates with the second connecting member to ensure that the combination of the first sub-body and the third sub-body and the combination of the second sub-body and the fourth sub-body maintain a tendency to approach each other.

10. The expandable intervertebral fusion cage according to claim 7, characterized in that: Any one of the first sub-body, the second sub-body, the third sub-body, and the fourth sub-body is recorded as a force-applying sub-body, wherein the one opposite to the force-applying sub-body on the left and right is recorded as a force-receiving sub-body, and the third inward surface, the fourth inward surface, the fifth inward surface, and the sixth inward surface are collectively recorded as inward surfaces; The second adjusting member is a rotating member, which is pivotally connected to the force-applying split body and the rotating plane is a vertical plane; the second adjusting member includes a second cam, a second rotating shaft and a second knob portion, which are coaxial and connected as a whole; The force-applying split body is provided with a second accommodating cavity, an inner surface of the force-applying split body is provided with a second opening communicating with the second accommodating cavity, and the second cam is arranged in the second accommodating cavity; The force-applying split body is provided with a second shaft hole, and the second rotating shaft passes through the second shaft hole and is adapted thereto; A second recessed groove is provided on the surface of the force-applying split body at a position corresponding to the second accommodating cavity, and the second recessed groove is connected to the second accommodating cavity through the second axial hole; the second knob portion is provided in the second recessed groove, and the thickness of the second knob portion does not exceed the depth of the second recessed groove; When the second knob is turned to rotate the second cam, the flange of the second cam extends out of the second accommodating cavity from the second opening at certain times and abuts against the inner surface of the force-bearing split body to push the assembly where the force-bearing split body is located to separate from the assembly where the force-applying split body is located.

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