Intervertebral fusion cage

Abstract

An intervertebral fusion cage comprises an upper lamina, a lower lamina, a first support column, a top of the first support column being fixedly connected with the upper lamina, a second support column, one side of the second support column being provided with a driving groove and a second transmission groove, a bottom of the second support column being fixedly connected with the lower lamina, a driving device, the driving device controlling rotation of a guide pulley, a first adjusting body, the first adjusting body being fixedly connected with the bottom of the first support column, a sliding rail, the sliding rail being fixedly arranged at one side of a transmission block, the sliding rail being a cylindrical body with a groove in the middle, the sliding rail being slidably connected with the guide pulley, a second adjusting body, the second adjusting body comprising a horizontal adjusting block, a first transmission groove and a transmission rod. The technical scheme of the present application effectively solves the technical problem that the intervertebral fusion cage is difficult to implant and has poor adaptability due to a large initial height.

Description

Technical Field

[0001] This invention relates to a prosthesis, and more particularly to an interbody fusion device. Background Technology

[0002] Interbody fusion is a common and effective treatment for spinal diseases such as lumbar degenerative diseases, lumbar instability, lumbar spondylolisthesis, and herniated discs. Its core principle lies in restoring and maintaining intervertebral disc height, improving lumbar alignment, maintaining local stability, and promoting bony fusion between adjacent vertebrae by implanting an interbody fusion cage. As a key instrument in this surgery, the size of the interbody fusion cage is closely related to patient prognosis, especially its height, which significantly impacts the surgical outcome. However, existing interbody fusion cages generally suffer from the following problems: First, traditional intervertebral fusion cages are typically of fixed height, while intervertebral disc height varies from person to person. It's difficult to adjust the cage height intraoperatively to suit different patients' needs, affecting the universality and applicability of the treatment. Inappropriate cage height selection can lead to a series of serious complications: an excessively high cage can cause excessive stretching of the intervertebral space, causing the preserved annulus fibrosus and anterior and posterior longitudinal ligaments to exert tensile forces against the stretching, resulting in endplate damage, cage subsidence, internal fixation failure, adjacent segment degeneration, and postoperative overstretching pain. Simultaneously, an excessively high cage or excessive stretching of the intervertebral space can also cause axial traction on nerve roots, leading to postoperative numbness, pain, and even foot drop in the lower limbs. Studies have shown that excessively high cage height is a significant risk factor for cage subsidence. Second, while some intervertebral fusion cages currently exist with height adjustment capabilities, these are generally large and complex, requiring larger surgical incisions during implantation and causing significant damage to surrounding tissues. With the continuous development of laparoscopic technology and minimally invasive surgery, the clinical requirements for minimally invasive fusion cage implantation are increasing. However, existing large-volume fusion cages cannot meet the needs of minimally invasive surgery for small incisions and minimal trauma, thus limiting their application in minimally invasive spinal surgery. Third, although existing expandable or height-adjustable fusion cages can expand in height after implantation, their initial height before implantation is still relatively large. This makes it difficult for the fusion cage to be successfully implanted into the intervertebral space through small surgical channels or incisions, increasing the difficulty of the operation and the risk of damage to surrounding tissues.

[0003] In summary, existing interbody fusion cages, due to their relatively large initial height, not only increase the difficulty of implantation and surgical trauma, but also easily lead to a series of postoperative complications due to improper height selection. Therefore, there is an urgent need for an interbody fusion cage that can have a smaller initial height, facilitate implantation into the intervertebral space through a minimally invasive channel or small incision, reduce implantation difficulty and surgical trauma, and allow for appropriate height adjustment after implantation to meet the intervertebral height requirements of different patients. Summary of the Invention

[0004] The purpose of this invention is to provide an interbody fusion device to solve the technical problems of difficult implantation and poor adaptability of interbody fusion devices due to their large initial height.

[0005] To solve the above-mentioned technical problems, the present invention provides an intervertebral fusion device, specifically comprising: an upper lamina and a lower lamina, the upper lamina being cuboid in shape and the lower lamina being arrowhead-shaped, with a triangular protrusion on one side of the lower lamina; a first support column, the top of which is fixedly connected to the upper lamina; a second support column, one side of which is provided with a driving groove and a second transmission groove, the bottom of which is fixedly connected to the lower lamina; and a driving device, comprising: a driving rod and a guide pulley, the driving rod being fixedly connected to the guide pulley for controlling the rotation of the guide pulley, the driving rod being rotatably disposed within the driving groove, and the guide pulley being a circle with a gradually changing diameter. The column is integrally formed with multiple sets of concave rotary curved grooves at intervals along the axial direction; the first adjusting body is fixedly connected to the bottom of the first supporting column, and includes: a transmission block, which is arrow-shaped, and the bottom of the transmission block is slidably fitted to the top of the lower cone plate; a slide rail, which is fixedly set on one side of the transmission block, and is a cylinder with a groove in the middle, and is slidably connected to a guide pulley; the second adjusting body includes a horizontal adjusting block, with a first transmission groove running through the center of the horizontal adjusting block, and a transmission rod fixedly set on one side of the horizontal adjusting block, and the transmission rod is horizontally movable in the second transmission groove.

[0006] Furthermore, the rotation axis of the drive rod is collinear with the rotation axis of the guide pulley. When the drive rod rotates, it causes the guide pulley to slide within the groove of the slide rail.

[0007] Furthermore, a damping layer is provided on the inner wall of the groove of the slide rail. The damping layer is used to increase the friction between the guide pulley and the slide rail to prevent the guide pulley from sliding relative to each other in the non-driving state.

[0008] Furthermore, a first limiting boss is provided on the inner wall of the drive groove, and a second limiting boss that matches the first limiting boss is provided on the outer peripheral wall of the drive rod. The first limiting boss and the second limiting boss cooperate to limit the rotation angle range of the drive rod in the drive groove.

[0009] Furthermore, a disc spring is provided between the upper vertebral plate and the second support column. Multiple disc springs are stacked in sequence to adjust the elastic support force between the upper vertebral plate and the second support column.

[0010] Furthermore, a ratchet is provided between the first adjusting body and the triangular protrusion of the lower vertebral plate, and the ratchet is used to control the relative displacement direction of the first adjusting body and the lower vertebral plate.

[0011] Furthermore, the surfaces of the upper and lower lamina that come into contact with autologous bone are provided with porous structures of bone-like trabeculae. The porosity of the porous structures of bone-like trabeculae is 50% to 85%, and the porous structures are integrally formed on the surfaces of the upper and lower lamina using additive manufacturing technology.

[0012] Applying the technical solution of this invention, there are an upper vertebral lamina and a lower vertebral lamina. The upper vertebral lamina is rectangular, and the lower vertebral lamina is arrowhead-shaped. A triangular protrusion is provided on one side of the lower vertebral lamina. A first support column is fixedly connected to the top of the upper vertebral lamina. A second support column is provided with a driving groove and a second transmission groove on one side, and the bottom of the second support column is fixedly connected to the lower vertebral lamina. A driving device includes a driving rod and a guide pulley. The driving rod is fixedly connected to the guide pulley and is used to control the rotation of the guide pulley. The driving rod is rotatably disposed in the driving groove. The guide pulley is a cylinder with a gradually changing diameter, integrally formed along the axial direction. The device features multiple sets of concave rotary curved grooves; a first adjusting body, which is fixedly connected to the bottom of a first support column, comprising: a transmission block, which is arrow-shaped and whose bottom is slidably fitted to the top of a lower conical plate; a slide rail, which is fixedly mounted on one side of the transmission block and is a cylinder with a groove in the middle, and is slidably connected to a guide pulley; and a second adjusting body, which includes a horizontal adjusting block, with a first transmission groove penetrating through the center of the horizontal adjusting block, and a transmission rod fixedly mounted on one side of the horizontal adjusting block, the transmission rod being horizontally movable within the second transmission groove. The above design effectively solves the technical problems of difficult implantation and poor adaptability of interbody fusion cages due to their large initial height. In the initial implantation stage, a rotating drive rod drives a guide pulley to rotate. Because the guide pulley is a cylinder with a gradually changing diameter, integrally formed with multiple sets of concave rotary curved grooves along the axial direction, the first adjustment body will experience displacement in two directions under the action of the slide rail: longitudinal and lateral displacement. This, in turn, causes the first support column to also experience the same displacement. Under the action of the transmission rod, the upper lamina will also experience displacement in two directions, thus changing the height and relative position between the upper and lower lamina. Through this design, the height of the interbody fusion cage can be reduced by adjustment before implantation, and after implantation, the cage can be restored to the preset height by adjustment. Attached Figure Description

[0013] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 The diagram shows a three-dimensional view of the interbody fusion device. Figure 2 A cross-sectional view of the interbody fusion device is shown; Figure 3 An exploded view of a portion of the interbody fusion device is shown; Figure 4 A triaxial view of the drive unit is shown; Figure 5 The diagram shows the relative positions of the superior and inferior lamina. The above-mentioned figures include the following reference numerals: 10, upper vertebral plate; 20, lower vertebral plate; 30, driving device; 301, driving rod; 302, guide pulley; 40, first adjusting body; 401, transmission block; 402, slide rail; 50, first support column; 60, second adjusting body; 601, horizontal adjusting block; 602, transmission rod; 603, first transmission groove; 70, second support column; 701, driving groove; 702, second transmission groove; 80, disc spring; 90, ratchet. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0015] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0016] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Any specific values ​​in all examples shown and discussed herein should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0017] like Figure 1-2The diagram shows an intervertebral fusion device comprising a superior lamina 10 and a inferior lamina 20. The superior and inferior lamina are respectively bonded to autologous bone lamina. The surfaces of the superior and inferior lamina in contact with the autologous bone are provided with a trabecular mesh structure. The porosity of the porous structure of the trabecular mesh structure is 50% to 85%, and the porous structure is integrally formed on the surfaces of the superior and inferior lamina using additive manufacturing technology to promote bone ingrowth. The superior lamina 10 is cuboid in shape, with an arc-shaped upper surface for bonding to the autologous bone lamina. The inferior lamina 20 is arrowhead-shaped, with a triangular protrusion on one side forming a slope.

[0018] The drive device 30 is placed above the lower vertebral plate 10. The drive device 30 includes a drive rod 301. A guide pulley 302 is fixedly sleeved on the outer side of the drive rod 301. The guide pulley 302 is a cylinder with a gradually changing diameter. Multiple sets of concave rotary curved grooves are integrally formed along the axial direction. The protruding part of the guide pulley can be set with different spacing and height. The guide pulley will not move longitudinally, but only rotates in the vertical plane.

[0019] The first adjusting body 40 is fixedly connected to the bottom of the first support column 50. The first adjusting body includes: a transmission block 401, which is arrow-shaped and has a triangular protrusion on one side. The protrusion forms an inclined surface that is slidably connected to the inclined surface formed by the lower cone plate 20; and a slide rail 402, which is fixedly installed on one side of the transmission block 401. The slide rail 402 is a cylinder with a groove in the middle and is slidably connected to the guide pulley 302. Since the guide pulley 302 is a cylinder with a gradually changing diameter, the slide rail 402 can move not only on the horizontal plane but also on the vertical plane.

[0020] like Figure 1 , 3 As shown, the intervertebral fusion device also includes a second adjustment body 60, which includes a horizontal adjustment block 601. A first transmission groove 603 is provided through the center of the horizontal adjustment block. A transmission rod 602 is fixedly provided on one side of the horizontal adjustment block. The second support column 70 is provided with a drive groove 701 and a second transmission groove 702. The transmission rod 602 is horizontally movable in the second transmission groove 702. The drive rod 301 of the drive device 30 is inserted into the drive groove 701.

[0021] like Figure 1-5As shown, with the above configuration, before the interbody fusion cage is implanted, the drive rod 301 is rotated, which drives the guide pulley 302 to rotate. Under the action of the slide rail 402, the first adjusting body 40 moves in the horizontal and vertical directions, thereby driving the first support column 50 to move in the horizontal and vertical directions. During this process, in order to increase the stability of the interbody fusion cage, a second adjusting body 60 is provided, and the horizontal adjusting block 601 is pulled out from the second transmission groove 702 of the second support column 70. The height H between the upper lamina 10 and the lower lamina 20 decreases, and the relative position L lengthens. Figure 5 This is a diagram showing the relative positions of the superior lamina 10 and the inferior lamina 20 in the sagittal plane. At this point, the volume of the interbody fusion cage is reduced to facilitate implantation. After implantation, through the above adjustments, the height H can be increased to conform to the body's own bone, while L is shortened to make the superior and inferior lamina flush.

[0022] like Figure 4 As shown, the rotation axis of the drive rod 301 is collinear with the rotation axis of the guide pulley 302. When the drive rod rotates, it drives the guide pulley to slide in the groove of the slide rail 402. The height of the intervertebral fusion device and the rate of change of the relative position of the upper and lower lamina can be adjusted by adjusting the protrusion height and the interval position of the guide pulley 302. Furthermore, by controlling the guide pulley, the relative position L of the upper and lower lamina can be zero after the final adjustment of the intervertebral fusion device.

[0023] To further improve the stability of the interbody fusion device, a damping layer is provided on the inner wall of the groove of the slide rail 402. The damping layer is used to increase the friction between the guide pulley and the slide rail. A first limiting boss is provided on the inner wall of the drive groove 701, and a second limiting boss matching the first limiting boss is provided on the outer peripheral wall of the drive rod 301. The first limiting boss and the second limiting boss cooperate to limit the rotation angle range of the drive rod in the drive groove. A disc spring 80 is also provided between the upper vertebral plate 10 and the second support column 70. Multiple disc springs are stacked sequentially to adjust the elastic support force between the upper vertebral plate and the second support column. A ratchet 90 is also provided between the triangular protrusions of the first adjusting body 40 and the lower vertebral plate 20. The ratchet is used to control the relative displacement direction of the first adjusting body and the lower vertebral plate and can ensure the overall mechanical performance of the interbody fusion device.

[0024] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0025] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0026] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An interbody fusion device, characterized in that, include: The upper vertebral lamina and the lower vertebral lamina are provided. The upper vertebral lamina is rectangular and the lower vertebral lamina is arrowhead shaped. A triangular protrusion is provided on one side of the lower vertebral lamina. The first support column, the top of which is fixedly connected to the upper vertebral plate; The second support column has a drive groove and a second transmission groove on one side, and the bottom of the second support column is fixedly connected to the lower vertebral plate. A driving device, comprising: a driving rod and a guide pulley, wherein the driving rod is fixedly connected to the guide pulley and is used to control the rotation of the guide pulley; the driving rod is rotatably disposed in a driving groove; and the guide pulley is a cylinder with a gradually changing diameter integrally formed with multiple sets of concave rotary curved grooves spaced along the axial direction. The first adjusting body is fixedly connected to the bottom of the first support column. The first adjusting body includes: a transmission block, which is arrow-shaped and whose bottom is slidably fitted to the top of the lower vertebral plate; and a slide rail, which is fixedly disposed on one side of the transmission block and is a cylinder with a groove in the middle. The slide rail is slidably connected to the guide pulley. The second adjusting body includes a horizontal adjusting block, a first transmission groove is provided through the center of the horizontal adjusting block, and a transmission rod is fixedly provided on one side of the horizontal adjusting block. The transmission rod is horizontally movable and is provided in the second transmission groove.

2. The interbody fusion device according to claim 1, characterized in that, The rotation axis of the drive rod is collinear with the rotation axis of the guide pulley. When the drive rod rotates, it drives the guide pulley to slide within the groove of the slide rail.

3. The interbody fusion device according to claim 1, characterized in that, A damping layer is also provided on the inner wall of the groove of the slide rail, which is used to increase the friction between the guide pulley and the slide rail.

4. The interbody fusion device according to claim 1, characterized in that, A first limiting boss is provided on the inner wall of the drive groove, and a second limiting boss that matches the first limiting boss is provided on the outer peripheral wall of the drive rod. The first limiting boss and the second limiting boss cooperate to limit the rotation angle range of the drive rod in the drive groove.

5. The interbody fusion device according to claim 1, characterized in that, A disc spring is also provided between the upper vertebral plate and the second support column. Multiple disc springs are stacked in sequence to adjust the elastic support force between the upper vertebral plate and the second support column.

6. The interbody fusion device according to claim 1, characterized in that, A ratchet is also provided between the first adjusting body and the triangular protrusion of the lower vertebral plate, and the ratchet is used to control the relative displacement direction of the first adjusting body and the lower vertebral plate.

7. The interbody fusion device according to claim 1, characterized in that, The surfaces of the upper and lower vertebral lamina that are in contact with autologous bone are provided with porous structures resembling bone trabeculae. The porosity of the porous structures resembling bone trabeculae is 50% to 85%, and the porous structures are integrally formed on the surfaces of the upper and lower vertebral lamina using additive manufacturing technology.

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