Intervertebral disc implant manufacturing method and intervertebral disc implant

Abstract

The invention discloses an intervertebral disc implant manufacturing method and an intervertebral disc implant. The manufacturing method of the intervertebral disc implant comprises the following steps that the upper bone plate and the lower bone plate are manufactured in an additive mode; an upper fiber ring and a lower fiber ring are manufactured through additive manufacturing, the upper fiber ring is connected to the lower side of the upper bone plate, and the lower fiber ring is connected to the upper side of the lower bone plate; the polymer nucleus pulposus is manufactured in the lower fiber ring or the upper fiber ring in an additive mode; and the lower end face of the upper fiber ring and the upper end face of the lower fiber ring are bonded. The intervertebral disc implant obtained through the manufacturing method of the intervertebral disc implant is more suitable for a human body to use, and the problem that vertebrae need to be cut off in a large scale in a traditional implantation operation can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of intervertebral disc implants, in particular to a manufacturing method of an intervertebral disc implant and an intervertebral disc implant. Background Art

[0002] The intervertebral disc is a cartilaginous connection between the vertebral bodies of two adjacent vertebrae, consisting of an outer annulus fibrosus and a central nucleus pulposus. Artificial intervertebral disc replacement is the preferred option for surgical intervention in the treatment of severe degenerative disc disease. The design goal of an artificial intervertebral disc implant is to reproduce the mechanical properties of a healthy intervertebral disc and restore the physiological movement of the spinal segment after implantation.

[0003] However, the existing intervertebral disc implants have a large difference in geometric structure from the human intervertebral disc, and have a large stiffness, which easily causes stress concentration on the adjacent upper and lower vertebral bodies and intervertebral discs, accelerating the degeneration of the adjacent vertebral bodies and intervertebral discs. In addition, during the implantation surgery of the existing intervertebral disc implants, it is necessary to first plane the vertebral surfaces above and below the necrotic intervertebral disc, and then install them on the vertebral bodies by means of internal fixation or continuing to cut and excavate installation grooves on the vertebral bodies. A large amount of vertebral bone needs to be cut during the operation, which undoubtedly increases the difficulty of the operation and is not conducive to the postoperative recovery of patients. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a manufacturing method of an intervertebral disc implant and an intervertebral disc implant.

[0005] The solution for the present invention to solve its technical problems is as follows: In a first aspect, a manufacturing method of an intervertebral disc implant is provided, including the following steps: Additively manufacture an upper bone plate and a lower bone plate; Additively manufacture an upper annulus fibrosus and a lower annulus fibrosus, wherein the upper annulus fibrosus is connected to the lower side of the upper bone plate, and the lower annulus fibrosus is connected to the upper side of the lower bone plate; Additively manufacture a polymer nucleus pulposus inside the lower annulus fibrosus or inside the upper annulus fibrosus; Bond the lower end surface of the upper annulus fibrosus and the upper end surface of the lower annulus fibrosus.

[0006] The present invention has at least the following beneficial effects: By using the additive manufacturing method to produce the solid upper bone plate and lower bone plate, the upper bone plate and lower bone plate can be designed by computer according to the patient's vertebrae. The manufactured upper bone plate and lower bone plate are more in line with the size and geometric structure of the human bone. In subsequent implantation surgeries, the upper bone plate can match the upper bone, and the lower bone plate can match the lower bone, without the need to extensively shave the patient's vertebrae, which is more conducive to the patient's postoperative recovery. The intervertebral disc implant manufactured by the method of the present invention for manufacturing intervertebral disc implants has a geometric structure that highly mimics the human intervertebral disc, can replace the original, degenerated and necrotic intervertebral disc in the human body, and be connected between the two vertebrae above and below the intervertebral disc, realizing the movements and deformations of the healthy intervertebral disc in all directions such as bending, twisting, shearing, and compression, achieving a high degree of biomimicry of the geometric structure, kinematic characteristics, and mechanical characteristics of the intervertebral disc implant, and reducing the concentration of stress on the adjacent upper and lower vertebrae.

[0007] As a further improvement of the above technical solution, the steps of additive manufacturing the upper bone plate and lower bone plate include the following steps: Design the sizes and geometric shapes of the upper bone plate and the lower bone plate according to the geometric characteristics of the patient's vertebrae; According to the designed sizes and geometric shapes, use metal materials to obtain the upper bone plate and the lower bone plate through laser additive manufacturing; Or according to the designed sizes and geometric shapes, use polyetheretherketone to obtain the upper bone plate and the lower bone plate through melt extrusion.

[0008] As a further improvement of the above technical solution, the upper bone plate and the lower bone plate respectively include a plate body and a first microstructure. The first microstructure is provided on the opposite sides of the two plate bodies. The first microstructure includes a plurality of protruding strips. The two ends of the protruding strips are respectively connected to the plate body, and the middle part of the protruding strip and the plate body together form micropores. The plate body and the first microstructure are formed by integral additive manufacturing.

[0009] As a further improvement of the above technical solution, the plurality of protruding strips in the same first microstructure are arranged in a single ring shape or a plurality of concentric ring shapes.

[0010] As a further improvement of the above technical solution, the steps of additive manufacturing the upper fibrous ring and the lower fibrous ring include the following steps: Design the sizes and geometric shapes of the upper fibrous ring and the lower fibrous ring according to the geometric characteristics of the patient's vertebrae; Use a polymer material to fill the first microstructure by means of photocuring or melt extrusion; According to the designed sizes and geometric shapes of the upper fibrous ring and the lower fibrous ring, use a polymer material to layer by layer stack to form the upper fibrous ring and the lower fibrous ring by means of photocuring or melt extrusion.

[0011] As a further improvement of the above technical solution, the upper bone plate and the lower bone plate respectively further include a second microstructure, the second microstructure is arranged on the opposite sides of the two plate bodies, the second microstructure includes a plurality of perforated units, and the plurality of perforated units are respectively connected to the plate bodies and arranged in an array, and the plate bodies and the second microstructure are formed by integrated additive manufacturing.

[0012] As a further improvement of the above technical solution, the polymer nucleus pulposus and the upper annulus fibrosus or the lower annulus fibrosus are formed by integrated additive manufacturing.

[0013] As a further improvement of the above technical solution, the step of additive manufacturing the polymer nucleus pulposus in the lower annulus fibrosus or the upper annulus fibrosus includes the following steps: Design the size and geometric shape of the polymer nucleus pulposus according to the geometric characteristics of the patient's vertebrae; According to the designed size and geometric shape of the nucleus pulposus, use a polymer material to form the polymer nucleus pulposus by means of photocuring or melt extrusion.

[0014] As a further improvement of the above technical solution, the upper annulus fibrosus and the lower annulus fibrosus are made by additive manufacturing with a photosensitive resin material; the polymer nucleus pulposus is made by additive manufacturing with a photosensitive resin material; the toughness of the photosensitive resin material used to manufacture the upper annulus fibrosus and the lower annulus fibrosus is higher than the toughness of the photosensitive resin material used to manufacture the polymer nucleus pulposus; the elasticity of the photosensitive resin material used to manufacture the polymer nucleus pulposus is higher than the elasticity of the photosensitive resin material used to manufacture the upper annulus fibrosus and the lower annulus fibrosus.

[0015] In a second aspect, a disc implant is proposed, which is made by using the disc implant manufacturing method described in any one of the above technical solutions. The disc implant includes an upper bone plate, a lower bone plate, an upper annulus fibrosus, a lower annulus fibrosus and a polymer nucleus pulposus. The lower surface of the upper annulus fibrosus is connected to the upper surface of the lower annulus fibrosus to form an annulus fibrosus main body, the polymer nucleus pulposus is arranged in the annulus fibrosus main body, the upper bone plate is connected to the upper end surface of the annulus fibrosus main body, and the lower bone plate is connected to the lower end surface of the annulus fibrosus main body.

[0016] The disc implant is customized according to the actual situation of the human body, can replace the original degenerated and necrotic disc in the human body, and is connected between the two vertebrae above and below the disc. Its mechanical and kinematic properties are closer to those of a healthy disc, reducing the stress on the adjacent discs and slowing down the degeneration of the adjacent discs. Moreover, the upper bone plate can match the bones above, and the lower bone plate can match the bones below, without a large amount of bone shaving of the patient's vertebrae, which is more conducive to the patient's postoperative recovery. Description of the Drawings

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly describe the drawings required for the description of the embodiments. Obviously, the described drawings are only a part of the embodiments of the present invention, rather than all the embodiments. Those skilled in the art can also obtain other design solutions and drawings based on these drawings without creative efforts.

[0018] Figure 1 is a flowchart of the method for manufacturing an intervertebral disc implant according to an embodiment of the present invention; Figure 2 is to execute Figure 1 The schematic diagram of the product structure obtained after step S100 in; Figure 3 is to execute Figure 1 The schematic diagram of the product structure obtained after step S200 in; Figure 4 is to execute Figure 1 The schematic diagram of the product structure obtained after step S300 in; Figure 5 is to execute Figure 1 The schematic diagram of the product structure obtained after step S500 in; Figure 6 is the overall structure schematic diagram of the intervertebral disc implant according to an embodiment of the present invention; Figure 7 is the structure schematic diagram of the upper bone plate and the lower bone plate of the intervertebral disc implant according to an embodiment of the present invention; Figure 8 is the structure schematic diagram of the annulus fibrosus main body and the polymer nucleus pulposus of the intervertebral disc implant according to an embodiment of the present invention; Figure 9 is Figure 1 The detailed flowchart of step S100 in; Figure 10 is Figure 1 The detailed flowchart of another embodiment of step S100 in; Figure 11 is the structure schematic diagram of the upper bone plate and the lower bone plate of the intervertebral disc implant according to another embodiment of the present invention; Figure 12 is the structure schematic diagram of the upper bone plate and the lower bone plate of the intervertebral disc implant according to another embodiment of the present invention; Figure 13 is the structure schematic diagram of the upper bone plate and the lower bone plate of the intervertebral disc implant according to another embodiment of the present invention; Figure 14 is Figure 1 The detailed flowchart of step S200 in; Figure 15 is Figure 1 The detailed flowchart of step S300 in.

[0019] Reference numerals: 101, upper bone plate; 102, lower bone plate; 103, first microstructure; 104, second microstructure; 105, plate body; 201, upper annulus fibrosus; 202, lower annulus fibrosus; 203, main body of annulus fibrosus; 301, high molecular nucleus pulposus. Detailed implementation manners

[0020] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described by referring to the drawings below are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0021] In the description of the present invention, the orientation descriptions such as up, down, front, back, left, right, etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0022] In the description of the present invention, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If the first and the second are described only for the purpose of distinguishing technical features, they should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, etc. should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0024] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts all belong to the scope of protection of the present invention. Each technical feature in the present invention can be combined interactively on the premise of not conflicting with each other.

[0025] There are three categories of existing intervertebral disc implants. The first category is implants made of metal materials. It uses metal blocks without kinematic pairs to replace the necrotic intervertebral disc and directly connect the upper and lower vertebral bodies, or uses two upper and lower metal blocks to form a spherical hinge kinematic pair to connect the upper and lower vertebral bodies respectively. The second category is implants assembled from two materials, metal and polymer. The metal serves as the bone plate connecting the vertebral bodies and part of the spherical hinge kinematic pair, and the polymer material serves as the other part of the spherical hinge kinematic pair between the metal bone plates connecting the vertebral bodies. The third category is intervertebral disc implants with bionic geometric structures. These intervertebral disc implants assemble metal bone plates with polymer structures similar to human intervertebral discs. Their degree-of-freedom characteristics are closer to those of real human intervertebral discs and can withstand loads such as compression, shear, bending in all directions, and torsion.

[0026] For the first category of intervertebral disc implants, the metal blocks without kinematic pairs connect the upper and lower vertebral bodies into an immovable whole, which cannot meet the bending and torsion movements of the patient's cervical and lumbar spines. Moreover, the vertebral bodies in the form of metal spherical hinges have a large deviation from the actual movement performance of the human intervertebral disc, and the stiffness of this type of intervertebral disc is large, which will cause stress concentration in the adjacent upper and lower vertebral bodies and intervertebral discs, accelerating the degeneration of the adjacent vertebral bodies and intervertebral discs.

[0027] For the second category of intervertebral disc implants, the spherical hinge kinematic pair composed of metal and polymer can achieve multi-degree-of-freedom movement. However, there are still deviations between the movement characteristics and mechanical characteristics of the spherical hinge and the real human intervertebral disc. The polymer materials used to manufacture the spherical hinge are usually high-strength and wear-resistant materials (such as polyethylene, etc.). The overall stiffness of this type of intervertebral disc implant is also very large, which will cause greater stress on the adjacent intervertebral discs and accelerate the degeneration of the adjacent intervertebral discs.

[0028] For the third category of intervertebral disc implants, the degree-of-freedom characteristics are already similar to those of the human intervertebral disc, and the stiffness of the polymer part is significantly lower than that of the previous two categories. However, the current polymer intervertebral disc implants can only be designed and manufactured by assembling two metal bone plates with polymer structures similar to human intervertebral discs into one body. The existing third-category intervertebral disc implants are not exactly the same as the human intervertebral disc in terms of geometric structure, and still cannot achieve the stiffness distribution and flexibility of a healthy human intervertebral disc.

[0029] In addition, the bone plates of the above three categories of intervertebral disc implants are all flat metal plates. During the implantation surgery, the vertebral surfaces above and below the necrotic intervertebral disc need to be planed first, and then they are installed on the vertebrae by means of internal fixation or further cutting and digging installation grooves on the vertebrae. That is, a large amount of vertebrae need to be cut during the surgery, which undoubtedly increases the difficulty of the surgery and is not conducive to the postoperative recovery of the patient.

[0030] An embodiment of the present invention provides a method for manufacturing an intervertebral disc implant. The size and geometric structure of the intervertebral disc implant manufactured by the embodiment of the present invention can be flexible and variable, and each component of the intervertebral disc implant can be adjusted according to the actual size and geometric shape of the patient's vertebrae, solving the problem of large-scale shaving of vertebrae in traditional implantation surgeries. Moreover, the stiffness and flexibility are more suitable for human use, avoiding the accelerated degeneration of adjacent intervertebral discs.

[0031] The method for manufacturing an intervertebral disc implant proposed in this embodiment includes step S100, step S200, step S300, and step S400. Refer to Figure 1 .

[0032] Step S100, additively manufacture the upper bone plate 101 and the lower bone plate 102. Refer to Figure 2 , the upper bone plate 101 and the lower bone plate 102 are respectively manufactured by additive manufacturing. It can be understood that additive manufacturing is 3D printing, which integrates computer-aided design, material processing and forming technology. Based on digital model files, through software and numerical control systems, special metal materials, non-metal materials, and medical biological materials are stacked layer by layer in ways such as extrusion, sintering, melting, photocuring, and spraying to manufacture solid objects. In this embodiment, the solid upper bone plate 101 and lower bone plate 102 are manufactured by additive manufacturing, and the upper bone plate 101 and lower bone plate 102 can be designed by computer according to the patient's vertebrae. The manufactured upper bone plate 101 and lower bone plate 102 are more in line with the size and geometric structure of the human skeleton. In subsequent implantation surgeries, the upper bone plate 101 can match the upper bone, and the lower bone plate 102 can match the lower bone, without the need to shave a large amount of the patient's vertebrae, which is more conducive to the patient's postoperative recovery.

[0033] Step S200, additively manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202. Refer to Figure 3 , in this embodiment, the upper annulus fibrosus 201 is manufactured by additive manufacturing and connected to the lower side of the upper bone plate 101, and the lower annulus fibrosus 202 is manufactured by additive manufacturing and connected to the upper side of the lower bone plate 102. It can be understood that by manufacturing the solid upper annulus fibrosus 201 and lower annulus fibrosus 202 by additive manufacturing, the upper annulus fibrosus 201 and lower annulus fibrosus 202 can be designed by computer according to the patient's vertebrae. The manufactured upper annulus fibrosus 201 and lower annulus fibrosus 202 are more in line with the size and geometric structure of the human skeleton.

[0034] Step S300, additively manufacture the polymer nucleus pulposus 301 inside the lower annulus fibrosus 202 or inside the upper annulus fibrosus 201. Refer to Figure 4, taking the case where the polymer nucleus pulposus 301 is arranged in the lower annulus fibrosus 202 as an example, when designing the lower annulus fibrosus 202, a space for arranging the polymer nucleus pulposus 301 needs to be reserved. It can be understood that the polymer nucleus pulposus 301 can be in a colloidal, aqueous or cavity without material form.

[0035] Step S400, bond the lower end face of the upper annulus fibrosus 201 and the upper end face of the lower annulus fibrosus 202. Refer to Figure 5 , after bonding the upper annulus fibrosus 201 and the lower annulus fibrosus 202, an annulus fibrosus main body 203 is formed, the polymer nucleus pulposus 301 is located inside the annulus fibrosus main body 203, and the annulus fibrosus main body 203 can play a role in protecting and supporting in the intervertebral disc.

[0036] It can be understood that the upper annulus fibrosus 201 and the lower annulus fibrosus 202 are made of the same polymer material by additive manufacturing methods such as stereolithography, fused extrusion, etc. If the upper annulus fibrosus 201 and the lower annulus fibrosus 202 are additively manufactured by stereolithography, when bonding, a stereolithography adhesive can be used to achieve bonding.

[0037] The intervertebral disc implant prepared by the method for manufacturing an intervertebral disc implant proposed in this embodiment, refer to Figure 6 , Figure 7 and Figure 8 , its geometric structure can highly mimic the human intervertebral disc, can replace the original, degenerated and necrotic intervertebral disc of the human body, and be connected between the two vertebrae above and below the intervertebral disc, realizing various movements and deformations of the healthy intervertebral disc such as bending, torsion, shear, compression, etc., and achieving a high degree of biomimicry of the geometric structure, kinematic characteristics and mechanical characteristics of the intervertebral disc implant.

[0038] In some embodiments, step S100 includes step S110 and step S120, refer to Figure 9 . In other embodiments, step S100 includes step S110 and step S130, refer to Figure 10 .

[0039] Step S110, design the sizes and geometric shapes of the upper bone plate 101 and the lower bone plate 102 according to the geometric characteristics of the patient's vertebrae. Through the geometric design of the upper bone plate 101 and the lower bone plate 102 according to the geometric characteristics of the patient's vertebrae, customized production of intervertebral disc implants for different patients is realized. During the subsequent implantation surgery, only the surface layer of the patient's vertebrae connecting the intervertebral disc needs to be shaved off to realize the implantation of the intervertebral disc implant. Since the intervertebral discs of different patients or different vertebral segments of the same patient are different, manufacturing customized intervertebral disc implants can greatly reduce the vertebrae shaved off during the operation and accelerate the patient's recovery.

[0040] Step S120: According to the designed size and geometric shape, use a metal material to obtain the upper bone plate 101 and the lower bone plate 102 through laser additive manufacturing. The metal material can be a titanium alloy material, a cobalt-chromium-molybdenum alloy material, etc. The upper bone plate 101 and the lower bone plate 102 obtained through laser additive manufacturing of the metal material have good biocompatibility, high strength, and corrosion resistance, and are suitable for long-term implantation. Among them, the elastic modulus of the titanium alloy material is close to that of the human bone and does not affect postoperative imaging examinations.

[0041] Step S130: According to the designed size and geometric shape, use polyetheretherketone to obtain the upper bone plate 101 and the lower bone plate 102 through melt extrusion. The elastic modulus of polyetheretherketone is close to that of the human bone, which can reduce stress shielding. Moreover, it has good radiopacity, which is convenient for observing bone fusion after surgery.

[0042] It can be understood that the additive manufacturing materials used for the annulus fibrosus and the bone plate are different. First, form the upper annulus fibrosus 201 and the upper bone plate 101 into a whole and form the lower annulus fibrosus 202 and the lower bone plate 102 into a whole, and then bond the upper annulus fibrosus 201 and the lower annulus fibrosus 202 to achieve the complete combination of the entire intervertebral disc implant, which can enhance the connection strength between the upper annulus fibrosus 201 and the upper bone plate 101 and the connection strength between the lower annulus fibrosus 202 and the lower bone plate 102.

[0043] In some embodiments, the upper bone plate 101 and the lower bone plate 102 respectively include a plate body 105 and a first microstructure 103. The first microstructure 103 is arranged on the facing sides of the two plate bodies 105, that is, the lower side of the plate body 105 of the upper bone plate 101 and the upper side of the plate body 105 of the lower bone plate 102. The first microstructure 103 and the plate body 105 are formed by integrated additive manufacturing. The first microstructure 103 includes a plurality of convex strips. The two ends of the convex strips are respectively connected to the plate body 105, and the middle part of the convex strips and the plate body 105 together form micropores.

[0044] It can be understood that the setting of the first microstructure 103 can make the lower surface of the upper bone plate 101 and the upper surface of the lower bone plate 102 uneven. When performing step S200, the materials used to manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202 can fill into the micropores of the first microstructure 103 and the gaps between adjacent convex strips. The two materials are intertwined and hooked, which can enable the annulus fibrosus and the bone plate to achieve a tight connection.

[0045] In some embodiments, the plurality of convex strips located in the same first microstructure 103 are arranged in a single circular arrangement, referring to Figure 13 . In other embodiments, the plurality of convex strips located in the same first microstructure 103 are arranged in a plurality of concentric circular arrangements, referring to Figure 7 、 Figure 11 and Figure 12 , Figure 7 、Figure 11 and Figure 12 The schematic first microstructure 103 is composed of three convex strips arranged in a concentric circular pattern. In this embodiment, the extension lines of the straight lines formed by connecting both ends of each convex strip pass through the center of the plate body 105, which conforms to the simulation of the anisotropy of the mechanical stiffness of the natural intervertebral disc. Moreover, the materials used to manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202 are filled into the micropores in different directions, which can further improve the connection tightness between the annulus fibrosus material and the bone plate material.

[0046] The shape and number of the convex strips can be adjusted according to actual needs on the premise of ensuring the tight combination of the annulus fibrosus and the bone plate. Referring to Figure 11 , the end face of the micropore formed by the convex strip and the plate body 105 is triangular, and the middle part of the convex strip forms a tip, which is arranged towards the other plate body 105. Referring to Figure 12 , the end face of the micropore formed by the convex strip and the plate body 105 is semi-circular, and the middle part of the convex strip forms an arc, which protrudes towards the other plate body 105. Referring to Figure 7 and Figure 13 , the end face of the micropore formed by the convex strip and the plate body 105 is rectangular, and the middle part of the convex strip is arranged parallel to the plate body 105.

[0047] The size of the convex strip can be adjusted according to actual needs on the premise of ensuring the tight combination of the annulus fibrosus and the bone plate. The convex strip should not be too large, and the height of the convex strip protruding towards the other plate body 105 does not exceed the thickness of the plate body 105.

[0048] In some embodiments, step S200 includes step S210, step S220, and step S230. Referring to Figure 14 .

[0049] Step S210, design the sizes and geometric shapes of the upper annulus fibrosus 201 and the lower annulus fibrosus 202 according to the geometric characteristics of the patient's vertebrae. According to the geometric characteristics of the patient's vertebrae, the distance between the upper and lower vertebrae can be determined to determine the relative positions between the upper bone plate 101 and the lower bone plate 102 and the thicknesses of the upper annulus fibrosus 201 and the lower annulus fibrosus 202, so as to keep the intervertebral disc height unchanged after replacing the intervertebral disc implant to ensure the maximum recovery of the range of motion.

[0050] Step S220, use a polymer material to fill the first microstructure 103 in a photocuring or melt extrusion manner. The first microstructure 103 on the lower surface of the upper bone plate 101 and the upper surface of the lower bone plate 102 realizes the combination of the bone plate and the annulus fibrosus, which can make the entire intervertebral disc implant an integral body and ensure the service performance.

[0051] Step S230: According to the designed sizes and geometric shapes of the upper annulus fibrosus 201 and the lower annulus fibrosus 202, use a polymer material to stack layer by layer in a way of photocuring or melt extrusion to form the upper annulus fibrosus 201 and the lower annulus fibrosus 202. Obtaining the upper annulus fibrosus 201 and the lower annulus fibrosus 202 by additive manufacturing according to the pre-designed sizes and geometric shapes can ensure that the space between the entire intervertebral disc implant and the patient's vertebrae is adapted, so as to maximize the restoration of the range of motion.

[0052] In some embodiments, the upper bone plate 101 and the lower bone plate 102 respectively include a second microstructure 104, and the second microstructure 104 is arranged on the opposite sides of the two plate bodies 105, that is, the upper side of the upper bone plate 101 and the lower side of the lower bone plate 102. The second microstructure 104 includes a plurality of perforated units, and the plurality of perforated units are respectively connected to the plate body 105 and arranged in an array, and the plate body 105 and the second microstructure 104 are formed by integral additive manufacturing.

[0053] It can be understood that the shapes, sizes, and numbers of the perforated units in the second microstructure 104 are not specifically limited herein. In some embodiments, referring to Figure 7 , the perforated units of the second microstructure 104 are composed of a plurality of rod-shaped members supporting each other, and the second microstructure 104 formed by connecting the plurality of perforated units is in a grid shape.

[0054] In other embodiments, the perforated unit is a raised block, and a notch is provided on the raised block. The shape of the notch is not specifically limited herein. Referring to Figure 11 、 Figure 12 and Figure 13 . Taking the second microstructure 104 in Figure 13 as an example, each raised block has an inner cavity, adjacent raised blocks are connected to each other, and the inner cavities are interconnected. In the second microstructure 104 located on the upper bone plate 101, a circular notch is provided at the upper end of the raised block, and the notch is interconnected with the inner cavity.

[0055] When implanting an intervertebral disc implant obtained by using the manufacturing method of this embodiment between the patient's vertebrae, the setting of the second microstructure 104 is beneficial to the growth of the vertebrae and promotes the combination of the vertebrae and the bone plate.

[0056] The second microstructure 104 can effectively promote the growth of the vertebrae in the intervertebral disc implant and enhance the combination of the bone plate and the vertebrae. By adjusting the size parameters of the second microstructure 104, the porosity in the second microstructure 104 can be flexibly controlled, so as to adjust the mechanical properties of the intervertebral disc implant to make it closer to the characteristics of natural bone tissue. It is found in practice that the porosity of the second microstructure 104 is preferably in the range of greater than or equal to 60% and less than or equal to 90%. To Figure 13Taking the second microstructure 104 as an example, the notch diameter thereof is preferably in the range of greater than or equal to 300 microns and less than or equal to 600 microns.

[0057] It can be understood that since the upper bone plate 101 and the lower bone plate 102 are formed by additive manufacturing, the first microstructure 103 and the second microstructure 104 are simple to process.

[0058] In some embodiments, in step S300, the polymer nucleus pulposus 301 and the upper annulus fibrosus 201 or the lower annulus fibrosus 202 are formed by integrated additive manufacturing. Using multi-material printing technology to manufacture the annulus fibrosus and the polymer nucleus pulposus 301 can simulate the mechanical stiffness anisotropy characteristics of the natural intervertebral disc and further improve the function and compatibility of the implant.

[0059] In some embodiments, step S300 includes step S310 and step S320, refer to Figure 15 。

[0060] Step S310, design the size and geometric shape of the polymer nucleus pulposus 301 according to the geometric characteristics of the patient's vertebra. The size of the nucleus pulposus may vary due to individual differences, age, and the specific location of the intervertebral disc (such as the cervical vertebra, thoracic vertebra, lumbar vertebra). In the design of the intervertebral disc implant, the size and geometric shape of the polymer nucleus pulposus 301 need to be adjusted according to the actual situation of the patient's vertebra to ensure that it can effectively perform its function.

[0061] Step S320, according to the designed size and geometric shape of the nucleus pulposus, use a polymer material to form the polymer nucleus pulposus 301 by means of photocuring or melt extrusion.

[0062] It can be understood that the mechanical stiffness of the upper annulus fibrosus 201 and the lower annulus fibrosus 202 can be adjusted within a wide range by replacing the polymer material used in additive manufacturing. Since the mechanical properties of different polymer materials are significantly different, and the upper annulus fibrosus 201 and the lower annulus fibrosus 202 are the main parts that play a role in protecting and supporting in the intervertebral disc, using different polymer materials as the preparation materials for the annulus fibrosus main body 203 will have a significant impact on the mechanical stiffness of the intervertebral disc implant.

[0063] In some embodiments, the upper annulus fibrosus 201, the lower annulus fibrosus 202, and the polymer nucleus pulposus 301 are all manufactured by additive manufacturing using a photosensitive resin material. The photosensitive resin used to manufacture the polymer nucleus pulposus 301 is different from the photosensitive resin used to manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202. Among them, the toughness of the photosensitive resin material used to manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202 is higher than that of the photosensitive resin material used to manufacture the polymer nucleus pulposus 301, while the elasticity of the photosensitive resin material used to manufacture the polymer nucleus pulposus 301 is higher than that of the photosensitive resin material used to manufacture the upper annulus fibrosus 201 and the lower annulus fibrosus 202.

[0064] In this embodiment, the upper annulus fibrosus 201 and the lower annulus fibrosus 202 are printed with a high-toughness photosensitive resin. The high-toughness photosensitive resin can be synthesized as needed or a commercial rubber-like resin such as Tango Plus can be used. Commercial TangoPlus has excellent elongation at break, outstanding durability, and high tear resistance. The polymer nucleus pulposus 301 functions to balance stress. It can evenly transfer the external force it bears to the surrounding upper annulus fibrosus 201 and lower annulus fibrosus 202, and then disperse the stress through the annulus fibrosus. This is printed with a high-elasticity photosensitive resin such as a photocurable hydrogel, commercial Tango, or synthesized as needed, and can transmit stress to the annulus fibrosus by changing its shape, performing the function of a healthy nucleus pulposus.

[0065] The intervertebral disc implant manufactured by the method for manufacturing an intervertebral disc implant according to the embodiment of the present invention is a new type of class III intervertebral disc implant. Metal or polyether ether ketone materials are used as the upper bone plate 101 and the lower bone plate 102, a polymer material is used as the annulus fibrosus, and a polymer material is used as the nucleus pulposus. All kinds of materials are formed by additive manufacturing. The entire intervertebral disc implant is completed by step-by-step additive manufacturing without a cumbersome assembly process. Additive manufacturing can realize the manufacture of an intervertebral disc implant with a high-fidelity design. The new type of class III intervertebral disc implant manufactured by the method for manufacturing an intervertebral disc implant proposed in the embodiment of the present invention can have the same geometric characteristics as a healthy human intervertebral disc. By adjusting the properties of the polymer material, the mechanical and kinematic characteristics of the intervertebral disc implant can be made closer to those of a healthy human intervertebral disc. This solves the defects in the mechanical and kinematic characteristics of the first and second types of intervertebral disc implants, improves the performance of the third type of intervertebral disc implant, and simplifies the process of manufacturing the third type of intervertebral disc implant. In addition, by designing a metal or polyether ether ketone bone plate with the same geometric characteristics as the surface of the vertebra, the drawback that a large amount of vertebra needs to be shaved off during the intervertebral disc implant surgery can be solved, and the implant surgery can be completed only by shaving off the surface layer at the connection between the vertebra and the intervertebral disc.

[0066] In a second aspect, the embodiment of the present invention proposes an intervertebral disc implant, referring to Figure 6 、 Figure 7 and Figure 8, which is manufactured by using the method for manufacturing an intervertebral disc implant proposed in any one of the embodiments of the first aspect. The intervertebral disc implant includes an upper bone plate 101, a lower bone plate 102, an upper annulus fibrosus 201, a lower annulus fibrosus 202, and a polymer nucleus pulposus 301. The lower surface of the upper annulus fibrosus 201 and the upper surface of the lower annulus fibrosus 202 are adhesively connected to form an annulus fibrosus main body 203. The polymer nucleus pulposus 301 is located within the annulus fibrosus main body 203. The upper bone plate 101 is disposed above the annulus fibrosus main body 203 and connected to the upper end surface of the upper annulus fibrosus 201, and the lower bone plate 102 is disposed below the annulus fibrosus main body 203 and connected to the lower end surface of the lower annulus fibrosus 202.

[0067] In some embodiments, both the upper bone plate 101 and the lower bone plate 102 have a second microstructure 104. For the second microstructure 104 distributed on the upper surface of the upper bone plate 101 and the lower surface of the lower bone plate 102, its function is to provide space for osteoblast attachment and blood vessel growth after implantation into the human body. After implantation, it is beneficial to the growth of vertebrae and promotes the combination of vertebrae with the upper bone plate 101 or the lower bone plate 102. The morphology of the second microstructure 104 has been described in detail in the first aspect and will not be elaborated here.

[0068] The geometric features of the intervertebral disc implant of this embodiment can be adjusted according to the actual situation of the human vertebrae and can be the same as the geometric features of a healthy human intervertebral disc. Its mechanical and kinematic properties are closer to those of a healthy intervertebral disc, reducing the stress on adjacent intervertebral discs and slowing down the degeneration of adjacent intervertebral discs. Moreover, due to being manufactured by using a multi-material printing technology, the intervertebral disc implant of this embodiment can achieve an anisotropic simulation of the mechanical stiffness of the natural intervertebral disc and provide better functions and compatibility.

[0069] The above has specifically described the preferred embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent variations or substitutions without departing from the spirit of the present invention. These equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for manufacturing an intervertebral disc implant, characterized in that, It includes the following steps: Additively manufacture the upper vertebral plate and the lower vertebral plate; Additively manufacture the upper annulus fibrosus and the lower annulus fibrosus, wherein the upper annulus fibrosus is connected to the lower side of the upper vertebral plate, and the lower annulus fibrosus is connected to the upper side of the lower vertebral plate; Additively manufacture a polymer nucleus pulposus within the lower annulus fibrosus or within the upper annulus fibrosus; Bond the lower end face of the upper annulus fibrosus and the upper end face of the lower annulus fibrosus.

2. The method for manufacturing an intervertebral disc implant according to claim 1, wherein The step of additively manufacturing the upper vertebral plate and the lower vertebral plate includes the following steps: Design the sizes and geometric shapes of the upper vertebral plate and the lower vertebral plate according to the geometric characteristics of the patient's vertebra; Obtain the upper vertebral plate and the lower vertebral plate by laser additive manufacturing using a metallic material according to the designed sizes and geometric shapes; Or obtain the upper vertebral plate and the lower vertebral plate by melt extrusion using polyetheretherketone according to the designed sizes and geometric shapes.

3. The method for manufacturing an intervertebral disc implant according to claim 1, characterized in that, The upper vertebral plate and the lower vertebral plate respectively include a plate body and a first microstructure. The first microstructure is arranged on the facing sides of the two plate bodies. The first microstructure includes a plurality of ridges. The two ends of each ridge are respectively connected to the plate body, and the middle part of the ridge and the plate body together form micropores. The plate body and the first microstructure are formed by integrated additive manufacturing.

4. The method for manufacturing an intervertebral disc implant according to claim 3, characterized in that, The plurality of ridges located in the same first microstructure are arranged in a single ring shape or a plurality of concentric ring shapes.

5. The method for manufacturing an intervertebral disc implant according to claim 3, wherein, The step of additively manufacturing the upper annulus fibrosus and the lower annulus fibrosus includes the following steps: Design the sizes and geometric shapes of the upper annulus fibrosus and the lower annulus fibrosus according to the geometric characteristics of the patient's vertebra; Fill the first microstructure with a polymer material by means of photocuring or melt extrusion; 6. The method for manufacturing an intervertebral disc implant according to claim 3, wherein, According to the designed sizes and geometric shapes of the upper annulus fibrosus and the lower annulus fibrosus, layer by layer stack a polymer material by means of photocuring or melt extrusion to form the upper annulus fibrosus and the lower annulus fibrosus.

7. The method for manufacturing an intervertebral disc implant according to claim 1, characterized in that, The upper vertebral plate and the lower vertebral plate respectively further include a second microstructure. The second microstructure is arranged on the opposite sides of the two plate bodies. The second microstructure includes a plurality of perforated units. The plurality of perforated units are respectively connected to the plate body and are arranged in an array. The plate body and the second microstructure are formed by integrated additive manufacturing.

8. The method for manufacturing an intervertebral disc implant according to claim 1, wherein, The polymer nucleus pulposus and the upper annulus fibrosus or the lower annulus fibrosus are formed by integrated additive manufacturing. The step of additively manufacturing a polymer nucleus pulposus within the lower annulus fibrosus or within the upper annulus fibrosus includes the following steps: Design the size and geometric shape of the polymer nucleus pulposus according to the geometric characteristics of the patient's vertebra; 9. The method for manufacturing an intervertebral disc implant according to claim 1, characterized in that, Form the polymer nucleus pulposus using a polymer material by means of photocuring or melt extrusion according to the designed size and geometric shape of the nucleus pulposus. The upper annulus fibrosus and the lower annulus fibrosus are additively manufactured using a photosensitive resin material; the polymer nucleus pulposus is additively manufactured using a photosensitive resin material; the toughness of the photosensitive resin material used for manufacturing the upper annulus fibrosus and the lower annulus fibrosus is higher than the toughness of the photosensitive resin material used for manufacturing the polymer nucleus pulposus; the elasticity of the photosensitive resin material used for manufacturing the polymer nucleus pulposus is higher than the elasticity of the photosensitive resin material used for manufacturing the upper annulus fibrosus and the lower annulus fibrosus.

10. An intervertebral disc implant, characterized in that, Manufactured by the method for manufacturing an intervertebral disc implant according to any one of claims 1 to 9, the intervertebral disc implant comprising an upper bone plate, a lower bone plate, an upper annulus fibrosus, a lower annulus fibrosus, and a polymer nucleus pulposus, wherein the lower surface of the upper annulus fibrosus is connected to the upper surface of the lower annulus fibrosus to form an annulus fibrosus main body, the polymer nucleus pulposus is disposed within the annulus fibrosus main body, the upper bone plate is connected to the upper end surface of the annulus fibrosus main body, and the lower bone plate is connected to the lower end surface of the annulus fibrosus main body.

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