Intervertebral disc prosthesis and method for manufacturing an intervertebral disc prosthesis

Abstract

The present application relates to the technical field of orthopedic artificial joint design and manufacturing, in particular to an intervertebral disc prosthesis and a preparation method thereof. The first plate body of the intervertebral disc prosthesis is provided with a semispherical groove on the side away from the first fixing seat; the second plate body is provided with a connecting slot on the side away from the second fixing seat; the nucleus pulposus prosthesis comprises a semispherical convex surface and a base, the semispherical convex surface is movably connected with the semispherical groove, and the base is connected with the connecting slot; the surfaces of the first plate body and the second plate body are both provided with gradient trabeculae, and the surfaces of the semispherical groove and the semispherical convex surface in contact with each other are both metal ceramic interfaces formed by zirconium-niobium surface oxidation. The upper end plate of the intervertebral disc prosthesis can keep relative movement with the nucleus pulposus prosthesis, and the contact friction interface of the relative movement is a metal ceramic interface formed by zirconium-niobium surface oxidation, so that the friction surface can reduce abrasion to the greatest extent, the wear resistance of the prosthesis is improved, the service life of the prosthesis is prolonged, the loosening of the prosthesis is improved, the metal allergic reaction and metal artifacts are reduced.

Description

Technical Field

[0001] This invention relates to the field of orthopedic artificial joint design and manufacturing technology, and more specifically, to an intervertebral disc prosthesis and a method for preparing the intervertebral disc prosthesis. Background Technology Artificial intervertebral discs, as orthopedic implantable medical devices, have achieved good results in treating cervical spondylosis with disc herniation and anterior compression. In recent years, with the aging population, increased computer use due to prolonged desk work, and the increasing frequency of car accidents causing disc injuries, the incidence of lumbar disc disease has risen rapidly. Treatment for disc disease includes both surgical and non-surgical methods. Non-surgical treatment can only relieve symptoms, not cure the condition, and a significant proportion of patients require surgery. Anterior discectomy and interbody fusion are considered the classic method for acute disc herniation, especially with the use of anterior plates, which effectively maintains vertebral alignment and intervertebral height, significantly reducing the incidence of postoperative bone graft subsidence and displacement. However, anterior fusion surgery still has some drawbacks. Although it effectively relieves symptoms in the affected segment, fusion leads to loss of physiological mobility in the affected segment and increased motion and load on adjacent segments, which may accelerate degeneration of adjacent segments to some extent. With patients' increasing demands for postoperative recovery and quality of life, as well as the continuous development of surgical techniques, this surgical method can no longer meet clinical needs. To solve the above problems, existing technologies have developed into the surgical method of artificial disc replacement.

[0002] Artificial disc replacement surgery is used for intervertebral disc herniation to reconstruct the vertebral joint function at the diseased stage. The intervertebral disc prosthesis includes the superior endplate, the inferior endplate, and the nucleus pulposus prosthesis group between the superior and inferior endplates. It can maintain the stability of the lumbar spine sequence, preserve the motor function, reduce the pressure on the adjacent intervertebral discs, and thus reduce the occurrence of adjacent intervertebral disc degeneration. However, in current artificial intervertebral disc technology, the nucleus pulposus prosthesis is made of metals such as titanium alloy. The distance between the superior and inferior endplates cannot be changed. When the spine is compressed, the artificial intervertebral disc cannot achieve the cushioning function of a real intervertebral disc, easily causing damage to the adjacent vertebral bodies. In addition, the relative motion interface of the artificial intervertebral disc is prone to abrasion, causing the prosthesis to loosen. At the same time, allergies to existing metal prostheses have been increasingly discovered. Symptoms of metal allergies after joint replacement surgery are mostly allergic dermatitis, such as eczema, urticaria, herpes, and vasculitis outbreaks, either locally or throughout the body. More complex allergic reactions can develop around the prosthesis, causing pain, aseptic inflammation, and prosthesis loosening. In MRI equipment, the metal prosthesis is magnetized by the gradient magnetic field generated by MRI, generating its own magnetic field. This self-generated magnetic field can disrupt the signal generated by the original gradient magnetic field, leading to MRI artifacts. Reducing artifacts is also an important aspect of improving metal prostheses.

[0003] Based on the above problems, there is an urgent need for an artificial intervertebral disc prosthesis that has good cushioning function, making it closer to the function of the original human intervertebral disc, while minimizing wear debris, metal allergy reaction and metal artifacts on the friction surface. Summary of the Invention

[0004] The objectives of this invention include, for example, providing an intervertebral disc prosthesis and a method for preparing the intervertebral disc prosthesis, wherein the superior endplate of the intervertebral disc prosthesis can maintain relative movement with the nucleus pulposus prosthesis, and the contact friction interface of their relative movement is a metal-ceramic interface with zirconium-niobium surface oxidation, thereby having a good buffering function, realizing the functional reconstruction of the human intervertebral disc, and the zirconium-niobium alloy has the effect of preventing metal allergic reactions and reducing metal artifacts, minimizing wear debris on the friction surface, improving prosthesis loosening, enhancing prosthesis wear resistance, and extending prosthesis service life.

[0005] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides an intervertebral disc prosthesis, which includes a superior endplate, a nucleus pulposus prosthesis, and a inferior endplate; The upper end plate includes a first plate body and a first fixing seat connected to the first plate body; a hemispherical groove is provided on the side of the first plate body opposite to the first fixing seat; The lower end plate includes a second plate body and a second fixing seat connected to the second plate body; a connecting slot is provided on the side of the second plate body opposite to the second fixing seat; The nucleus pulposus prosthesis includes a hemispherical convex surface and a base. The hemispherical convex surface and the hemispherical groove are movably fitted together, and the base is connected to the connecting slot. The first plate is provided with gradient bone trabeculae on the surface where it connects to the first fixation base and on the surface of the first fixation base. The second plate is provided with gradient bone trabeculae on the surface where it connects to the second fixation base and on the surface of the second fixation base. The surfaces where the hemispherical groove and the hemispherical convex surface contact each other are metal-ceramic interfaces formed by the oxidation of zirconium and niobium surfaces.

[0006] In an optional embodiment, the surface porosity of the surface where the first plate is connected to the first fixed base is gradually reduced from 80% to 40%; the surface porosity of the surface where the second plate is connected to the second fixed base is gradually reduced from 80% to 40%.

[0007] In an optional embodiment, the nucleus pulposus prosthesis is machined from a zirconium-niobium alloy forging; both the upper and lower endplates are 3D printed from zirconium-niobium alloy powder.

[0008] In an optional embodiment, the lower endplate and the nucleus pulposus prosthesis are integrally formed into a spherical convex lower endplate, and both the upper endplate and the spherical convex lower endplate are 3D printed using zirconium-niobium alloy powder.

[0009] In an optional embodiment, the surfaces where the hemispherical groove and the hemispherical convex surface contact each other have a microtextured structure.

[0010] In a second aspect, the present invention provides a method for preparing an intervertebral disc prosthesis, comprising: Using zirconium-niobium alloy powder as 3D printing raw material, the first intermediate product of the upper end plate and the first intermediate product of the lower end plate are produced by 3D printing to manufacture zirconium-niobium alloy forgings for the nucleus pulposus prosthesis. The first intermediate product of the upper endplate, the first intermediate product of the lower endplate, and the zirconium-niobium alloy forging of the nucleus pulposus prosthesis are processed to obtain the upper endplate, the lower endplate, and the nucleus pulposus prosthesis. Alternatively, the nucleus pulposus prosthesis and the lower endplate are integrally molded into a spherical convex lower endplate. Zirconium-niobium alloy powder is used as the raw material for 3D printing, and the first intermediate product of the upper endplate and the first intermediate product of the spherical convex lower endplate are produced by 3D printing. The first intermediate product of the upper endplate and the first intermediate product of the spherical convex lower endplate are processed to obtain the upper endplate and the spherical convex lower endplate.

[0011] In an optional embodiment, the steps of processing the upper endplate first intermediate product, the lower endplate first intermediate product, and the zirconium-niobium alloy forging of the nucleus pulposus prosthesis to obtain the upper endplate, the lower endplate, and the nucleus pulposus prosthesis include: The first intermediate product of the upper end plate and the first intermediate product of the lower end plate are placed in a hot isostatic pressing furnace, heated to 750℃-1100℃ under helium or argon protection, and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate and the second intermediate product of the lower end plate. The second intermediate product of the upper end plate and the second intermediate product of the lower end plate are machined, polished, cleaned and dried. The pit surface of the second intermediate product of the upper end plate is made with microtexture to obtain the third intermediate product of the upper end plate and the third intermediate product of the lower end plate. The zirconium-niobium alloy forging of the nucleus pulposus prosthesis is machined, polished, cleaned and dried to obtain the intermediate product of the nucleus pulposus prosthesis. A microtexture is prepared on the outer surface of the intermediate product of the nucleus pulposus prosthesis so that the surface roughness of the nucleus pulposus prosthesis except for the microtexture part is Ra≤0.050μm. The upper endplate third intermediate product, the lower endplate third intermediate product, and the nucleus pulposus prosthesis intermediate product were placed in a tube furnace and an inert gas with an oxygen mass percentage of 5%-15% was introduced at atmospheric pressure. The furnace was heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then allowed to cool naturally to below 50℃ before being removed to obtain the upper endplate, lower endplate, and nucleus pulposus prosthesis.

[0012] In an optional embodiment, the step of processing the upper endplate first intermediate product and the spherical convex lower endplate first intermediate product to obtain the upper endplate and the spherical convex lower endplate includes: The first intermediate product of the upper end plate and the first intermediate product of the spherical convex lower end plate are placed in a hot isostatic pressing furnace, heated to 750℃-1100℃ under helium or argon protection, and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate and the second intermediate product of the spherical convex lower end plate. The second intermediate product of the upper endplate and the second intermediate product of the spherical convex lower endplate were machined, polished, cleaned and dried. A microtextured structure was made on the pit surface of the second intermediate product of the upper endplate to obtain the third intermediate product of the upper endplate and the third intermediate product of the spherical convex lower endplate. A microtextured structure was prepared on the outer surface of the nucleus pulposus prosthesis intermediate product so that the surface roughness of the nucleus pulposus prosthesis except for the microtextured structure part is Ra≤0.050μm. The upper endplate third intermediate product and the spherical convex lower endplate third intermediate product are placed in a tube furnace and an atmospheric pressure inert gas with an oxygen mass percentage of 5%-15% is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain the upper endplate and the spherical convex lower endplate.

[0013] In an optional embodiment, the microtexture structure is configured to be prepared by using micro-milling, turning and laser processing mechanical methods to produce micron-scale and / or nano-scale microtextures, and the microtexture structure is a concave or convex microstructure of different shapes on the surface of zirconium-niobium alloy, or a multi-level scale composite structure.

[0014] In an optional embodiment, the particle diameter of the zirconium-niobium alloy powder is 5-150 micrometers.

[0015] The beneficial effects of the embodiments of the present invention include: The intervertebral disc prosthesis includes a superior endplate, a nucleus pulposus prosthesis, and a inferior endplate. A hemispherical groove is provided on the side of the first plate facing away from the first fixation seat. A connecting slot is provided on the side of the second plate facing away from the second fixation seat. The nucleus pulposus prosthesis includes a hemispherical convex surface and a base. The hemispherical convex surface movably engages with the hemispherical groove, and the base connects to the connecting slot. Gradient trabeculae are provided on the surfaces of the first plate connecting to the first fixation seat, the surface of the first fixation seat, the surface of the second plate connecting to the second fixation seat, and the surface of the second fixation seat. The contact surfaces of the hemispherical groove and the hemispherical convex surface are all metal-ceramic interfaces formed by the oxidation of zirconium and niobium surfaces. The superior endplate of this intervertebral disc prosthesis can maintain relative movement with the nucleus pulposus prosthesis, and the contact friction interface of their relative movement is a metal-ceramic interface formed by the oxidation of zirconium and niobium surfaces, thus providing excellent cushioning function and achieving functional reconstruction of the intervertebral disc. Furthermore, the zirconium-niobium alloy has the effect of preventing metal allergic reactions and reducing metal artifacts. The friction surface minimizes wear debris, improves prosthesis loosening, enhances prosthesis wear resistance, and extends the service life of the prosthesis. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the intervertebral disc prosthesis in an embodiment of the present invention; Figure 2 This is a cross-sectional view of the intervertebral disc prosthesis in an embodiment of the present invention; Figure 3 This is a diagram showing the location of the microtexture structure of the nucleus pulposus prosthesis in an embodiment of the present invention; Figure 4 This is a schematic diagram of the microtexture structure of an intervertebral disc prosthesis in an embodiment of the present invention; Figure 5 This is a schematic diagram of another microtexture structure of the intervertebral disc prosthesis in an embodiment of the present invention; Figure 6 This is a cross-sectional view of the spherical convex lower endplate in an embodiment of the present invention.

[0018] Icons: 100 - Intervertebral disc prosthesis; 110 - Upper endplate; 120 - Nucleus pulposus prosthesis; 130 - Lower endplate; 111 - First plate body; 112 - First fixation seat; 113 - Hemispherical groove; 121 - Hemispherical convex surface; 122 - Base; 131 - Second plate body; 132 - Second fixation seat; 133 - Connecting slot; 141 - Fixing bolt; 142 - Microtexture structure; 150 - Spherical convex lower endplate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and 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 of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] Please refer to Figures 1-3 This embodiment provides an intervertebral disc prosthesis 100, which includes a superior endplate 110, a nucleus pulposus prosthesis 120, and a inferior endplate 130. The upper end plate 110 includes a first plate body 111 and a first fixing seat 112 connected to the first plate body 111; a hemispherical groove 113 is provided on the side of the first plate body 111 away from the first fixing seat 112; The lower end plate 130 includes a second plate body 131 and a second fixing seat 132 connected to the second plate body 131; a connecting slot 133 is provided on the side of the second plate body 131 opposite to the second fixing seat 132; The nucleus pulposus prosthesis 120 includes a hemispherical convex surface 121 and a base 122. The hemispherical convex surface 121 is movably engaged with the hemispherical groove 113, and the base 122 is connected to the connecting slot 133 and fixed by a fixing bolt 141. The first plate 111 is connected to the first fixation base 112 and the surface of the first fixation base 112 are both provided with gradient bone trabeculae. The second plate 131 is connected to the second fixation base 132 and the surface of the second fixation base 132 are both provided with gradient bone trabeculae. The surfaces of the hemispherical groove 113 and the hemispherical convex surface 121 that come into contact with each other are metal-ceramic interfaces formed by the oxidation of zirconium and niobium surfaces.

[0026] As can be seen from the above, please refer to... Figures 1-3 The intervertebral disc prosthesis 100 includes a superior endplate 110, a nucleus pulposus prosthesis 120, and a inferior endplate 130. A hemispherical groove 113 is provided on the side of the first plate 111 opposite to the first fixation seat 112. A connecting slot 133 is provided on the side of the second plate 131 opposite to the second fixation seat 132. The nucleus pulposus prosthesis 120 includes a hemispherical convex surface 121 and a base 122. The hemispherical convex surface 121 is movably engaged with the hemispherical groove 113, and the base 122 is connected to the connecting slot 133. Thus, the nucleus pulposus prosthesis 120 can be installed on the inferior endplate 130 through this arrangement. Due to the movable engagement of the hemispherical convex surface 121 and the hemispherical groove 113, the superior endplate 110 can move relative to the nucleus pulposus prosthesis 120 installed on the inferior endplate 130, thereby allowing the superior endplate 110 to maintain relative movement with the nucleus pulposus prosthesis 120. Furthermore, since the surfaces of the first plate 111 and the first fixation base 112, the surface of the first fixation base 112, the surfaces of the second plate 131 and the second fixation base 132, and the surface of the second fixation base 132 are all provided with gradient bone trabeculae, and the surfaces of the hemispherical groove 113 and the hemispherical convex surface 121 that come into contact with each other are all metal-ceramic interfaces formed by the oxidation of zirconium and niobium surfaces; through this arrangement, the wear debris at the moving interface can be reduced during the relative movement of the upper endplate 110 and the nucleus pulposus prosthesis 120, thereby avoiding prosthesis loosening due to wear, while also preventing metal prosthesis allergies, and also avoiding artifacts on MRI; In summary, the superior endplate 110 of the intervertebral disc prosthesis 100 can maintain relative movement with the nucleus pulposus prosthesis 120, and the contact friction interface of their relative movement is a metal-ceramic interface with zirconium-niobium surface oxidation, which has a good buffering function, realizes the functional reconstruction of the human intervertebral disc, and the zirconium-niobium alloy has the effect of preventing metal allergic reaction and reducing metal artifacts. The friction surface minimizes wear debris, improves prosthesis loosening, enhances prosthesis wear resistance, and extends prosthesis service life.

[0027] Further, please refer to Figures 1-6In this embodiment, when configuring the first plate 111 and the second plate 131, the surface porosity of the surface of the first plate 111 connected to the first fixing seat 112 is gradually reduced from 80% to 40%; the surface porosity of the surface of the second plate 131 connected to the second fixing seat 132 is gradually reduced from 80% to 40%.

[0028] In the fabrication of the upper endplate 110, the nucleus pulposus prosthesis 120, and the lower endplate 130, the nucleus pulposus prosthesis 120 is machined from a zirconium-niobium alloy forging; the upper endplate 110 and the lower endplate 130 are both 3D printed using zirconium-niobium alloy powder. After being fabricated separately, they are then assembled. In other embodiments of the invention, the lower endplate 130 and the nucleus pulposus prosthesis 120 can be integrally formed into a spherical convex lower endplate 150, with both the upper endplate 110 and the spherical convex lower endplate 150 being 3D printed using zirconium-niobium alloy powder.

[0029] In addition, please refer to Figures 1-6For smooth friction interfaces in prostheses, traditional tribological views hold that the smoother the surface, the less friction. Surface microtextures have a significant impact on reducing interfacial friction and wear. With the further development of bionics, it has been discovered that organisms, during long-term evolution, develop special microstructures on their body surfaces to adapt to harsh environments and protect themselves from harm. Examples include the barbs on a pigeon's feathers, the skin texture of a shark, and the scales on a desert lizard. The presence of these microstructures can effectively reduce friction and wear on contact surfaces. Microtextures have been proven to be an effective means of creating friction-resistant and anti-friction surfaces. Experimental tests show that non-smooth surfaces with certain regular shapes in the biological world can improve surface lubrication and reduce adhesion and friction. The type, distribution, and size of surface microtextures have a significant impact on the tribological properties of friction pairs. Under lubricated conditions, designing and fabricating reasonable surface microtextures can effectively improve the frictional performance of friction pairs, achieving drag and wear reduction. Laser processing of microstructures (micro-concave or micro-convex shaped surfaces arranged in a certain pattern) can maintain a series of qualities of implant materials, keeping the material itself unchanged, while significantly improving the overall performance of the material. The lubrication state between friction pairs in artificial hip joints is determined by the interaction between biomolecules in synovial fluid and artificial joints, and this interaction is related to the wetting properties of materials. Wettability is a characterization of the ability of a liquid to spread on a solid surface. The hydrophilicity and hydrophobicity of a surface can be defined by the size of the contact angle θ. When θ < 90°, the material surface is hydrophilic, and when θ ≥ 90°, the opposite is true. Wettability affects the wetting of the lubricating fluid on the surface of the hip joint and the slip characteristics of the interface. For implantable biomaterials, the friction and wear of the implanted prosthesis contact interface will take place in physiological tissue fluid. The presence of microtexture can reduce friction and wear: (1) Micro-pits can store the wear debris generated during the friction process, avoiding the rough peaks of the contact pair surface and the wear particles forming a three-body wear that is extremely unfavorable to the friction process; (2) Store synovial fluid, so that the friction pair changes from the boundary lubrication state to the mixed lubrication state, or even the fluid lubrication state; generate hydrodynamic pressure to enhance the bearing capacity of the lubricating film and improve the friction and lubrication state; (3) The presence of microtexture increases the bonding strength of the zirconium-niobium alloy oxide layer. Based on this, the surfaces where the hemispherical groove 113 and the hemispherical convex surface 121 contact each other have a microtexture structure 142. It should be noted that the microtexture structure 142 is configured to be fabricated on a dense solid structure before the zirconium-niobium alloy is oxidized, and then the zirconium-niobium alloy is oxidized to a metal-ceramic interface. Furthermore, the microtexture structure 142 is configured to be fabricated using micro-milling, turning, and laser processing methods to create micron-scale and / or nano-scale microtextures; and the microtexture structure 142 is a concave or convex microstructure of different shapes on the surface of the zirconium-niobium alloy, or a multi-level scale composite structure. Therefore, please refer to Figures 1-6With the above structural arrangement, when the first fixing seat 112 and the second fixing seat 132 are configured, the first fixing seat 112 is connected to the upper surface of the upper end plate 110, and the lower surface of the upper end plate 110 is a hemispherical groove 113, while the second fixing seat 132 is connected to the lower surface of the lower end plate 130, and the upper surface of the lower end plate 130 is a connecting slot 133. Therefore, the first fixation seat 112 can be configured as two U-shaped fixation posts on the upper part of the upper endplate 110. Based on this, the upper surface of the upper endplate 110 and the surface of the U-shaped fixation posts are gradient bone trabeculae. The porosity of the upper surface ranges from 80% to 40% and then to a solid structure. The lower surface is provided with a hemispherical groove 113 to connect with the nucleus pulposus prosthesis 120. The nucleus pulposus prosthesis 120 includes a hemispherical convex surface 121 and a base 122. The hemispherical convex surface 121 is located above the base 122 and is an integral structure. The hemispherical convex surface 121 and the hemispherical groove 113 on the lower surface of the upper endplate 110 fit each other and can rotate relative to each other. The second fixation seat 132 consists of two U-shaped fixation posts connected to the lower surface of the lower endplate 130. The lower surface of the lower endplate 130 and the surface of the U-shaped fixation posts are gradient trabeculae. The porosity of the lower surface ranges from 80% to 40% and then to a solid structure. The upper part of the lower endplate 130 is provided with a connection slot 133. The base 122 of the nucleus pulposus prosthesis 120 is assembled and connected to the connection slot 133 for relative fixation. Among them, the nucleus pulposus prosthesis 120 is made of zirconium-niobium alloy forging; the upper endplate 110 and the lower endplate 130 are both made of zirconium-niobium alloy powder raw materials and are manufactured by 3D printing; the contact friction interface between the upper endplate 110 and the nucleus pulposus prosthesis 120 is a metal-ceramic interface formed by oxidation of zirconium-niobium surface.

[0030] It should be noted that, according to research, zirconium-niobium alloy is composed only of zirconium and niobium, and does not contain easily allergenic elements such as Ni and Co, with a Cr content of 0.005%. Experimental verification shows a sensitization level of 0. By oxidizing the surface of the zirconium-niobium alloy to a ceramic material, the zirconium-niobium prosthesis can avoid the precipitation of metal ions, further reducing the risk of postoperative metal allergies. In addition, zirconium-niobium alloy has excellent corrosion resistance, mechanical properties, and good biocompatibility, and is increasingly being used in the medical device field. One side is a smooth, low-wear surface of zirconium-niobium cermet, forming a sliding friction interface with other components; the other side is a 3D-printed zirconium-niobium alloy trabecular bone structure interface with excellent biocompatibility, and the trabecular bone structure interface facilitates integration with the bone interface. Therefore, this intervertebral disc prosthesis 100 is made of zirconium-niobium alloy, and its friction interface is a micro-textured cermet layer, making it more wear-resistant. The superior endplate 110 and the nucleus pulposus prosthesis 120, or the superior endplate 110 and the inferior endplate 130 with a spherical protrusion, can move relative to each other, forming a micro-movement process between the vertebral bodies; the 3D-printed trabecular interface is conducive to osseointegration, and the stepped trabecular structure has a good buffering function, making it closer to the function of the original human intervertebral disc; the zirconium-niobium metal prosthesis reduces MRI artifacts, avoids the risk of prosthesis metal allergy and loosening, and has long-term stability.

[0031] Based on the above, please refer to Figures 1-6 This invention provides a method for preparing an intervertebral disc prosthesis 100, which includes: Using zirconium-niobium alloy powder as 3D printing raw material, the upper end plate 110 first intermediate product and the lower end plate 130 first intermediate product are manufactured by 3D printing, and the nucleus pulposus prosthesis 120 zirconium-niobium alloy forging is manufactured. The upper endplate 110, the lower endplate 130, and the nucleus pulposus prosthesis 120 zirconium-niobium alloy forgings are processed to obtain the upper endplate 110, the lower endplate 130, and the nucleus pulposus prosthesis 120. Alternatively, the nucleus pulposus prosthesis 120 and the lower endplate 130 are integrally formed into a spherical convex lower endplate 150. Zirconium-niobium alloy powder is used as the raw material for 3D printing, and the upper endplate 110 and the spherical convex lower endplate 150 are produced by 3D printing. The first intermediate product of the upper end plate 110 and the first intermediate product of the spherical convex lower end plate 150 are processed to obtain the upper end plate 110 and the spherical convex lower end plate 150.

[0032] Furthermore, in this embodiment, when the lower endplate 130 and the nucleus pulposus prosthesis 120 are manufactured separately, the steps of processing the first intermediate product of the upper endplate 110, the first intermediate product of the lower endplate 130, and the zirconium-niobium alloy forging of the nucleus pulposus prosthesis 120 to obtain the upper endplate 110, the lower endplate 130, and the nucleus pulposus prosthesis 120 include: The first intermediate product of the upper end plate 110 and the first intermediate product of the lower end plate 130 are placed in a hot isostatic pressing furnace. Under the protection of helium or argon, the temperature is raised to 750℃-1100℃ and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal and cooled to below 250℃ in the furnace to obtain the second intermediate product of the upper end plate 110 and the second intermediate product of the lower end plate 130. The second intermediate product of the upper end plate 110 and the second intermediate product of the lower end plate 130 are machined, polished, cleaned and dried. A microtexture structure 142 is made on the surface of the pits of the second intermediate product of the upper end plate 110 to obtain the third intermediate product of the upper end plate 110 and the third intermediate product of the lower end plate 130. The zirconium-niobium alloy forging of the nucleus pulposus prosthesis 120 is machined, polished, cleaned and dried to obtain the intermediate product of the nucleus pulposus prosthesis 120. A microtexture structure 142 is prepared on the outer surface of the intermediate product of the nucleus pulposus prosthesis 120 so that the surface roughness of the nucleus pulposus prosthesis 120 excluding the part of the microtexture structure 142 is Ra≤0.050μm. The third intermediate product of upper endplate 110, the third intermediate product of lower endplate 130, and the intermediate product of nucleus pulposus prosthesis 120 are placed in a tube furnace, and an inert gas with an oxygen mass percentage of 5%-15% at atmospheric pressure is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain upper endplate 110, lower endplate 130, and nucleus pulposus prosthesis 120.

[0033] Further, please refer to Figures 1-6 In an embodiment of the present invention, when the lower endplate 130 and the nucleus pulposus prosthesis 120 are integrally manufactured, the step of processing the first intermediate product of the upper endplate 110 and the first intermediate product of the spherical convex lower endplate 150 to obtain the upper endplate 110 and the spherical convex lower endplate 150 includes: The first intermediate product of the upper end plate 110 and the first intermediate product of the spherical convex lower end plate 150 are placed in a hot isostatic pressing furnace. Under the protection of helium or argon, the temperature is raised to 750℃-1100℃, and then kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate 110 and the second intermediate product of the spherical convex lower end plate 150. The second intermediate product of the upper endplate 110 and the second intermediate product of the spherical convex lower endplate 150 are machined, polished, cleaned and dried. A microtexture structure 142 is made on the pit surface of the second intermediate product of the upper endplate 110 to obtain the third intermediate product of the upper endplate 110 and the third intermediate product of the spherical convex lower endplate 150. A microtexture structure 142 is prepared on the outer surface of the intermediate product of the nucleus pulposus prosthesis 120 so that the surface roughness of the nucleus pulposus prosthesis 120 excluding the part of the microtexture structure 142 is Ra≤0.050μm. The third intermediate product of the upper end plate 110 and the third intermediate product of the spherical convex lower end plate 150 are placed in a tube furnace, and an atmospheric pressure inert gas with an oxygen mass percentage of 5%-15% is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain the upper end plate 110 and the spherical convex lower end plate 150.

[0034] As can be seen from the above, the method for preparing the intervertebral disc prosthesis 100 includes both separate fabrication methods for the inferior endplate 130 and the nucleus pulposus prosthesis 120, and integrated fabrication methods for the inferior endplate 130 and the nucleus pulposus prosthesis 120. Specifically, when using the separate fabrication method for the inferior endplate 130 and the nucleus pulposus prosthesis 120, the detailed steps of the method for preparing the intervertebral disc prosthesis 100 are as follows: Using zirconium-niobium alloy powder as 3D printing raw material, the upper end plate 110 first intermediate product and the lower end plate 130 first intermediate product are manufactured by 3D printing, and the nucleus pulposus prosthesis 120 zirconium-niobium alloy forging is manufactured. The first intermediate product of the upper end plate 110 and the first intermediate product of the lower end plate 130 are placed in a hot isostatic pressing furnace. Under the protection of helium or argon, the temperature is raised to 750℃-1100℃ and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal and cooled to below 250℃ in the furnace to obtain the second intermediate product of the upper end plate 110 and the second intermediate product of the lower end plate 130. The second intermediate product of the upper end plate 110 and the second intermediate product of the lower end plate 130 are machined, polished, cleaned and dried. A microtexture structure 142 is made on the surface of the pits of the second intermediate product of the upper end plate 110 to obtain the third intermediate product of the upper end plate 110 and the third intermediate product of the lower end plate 130. The zirconium-niobium alloy forging of the nucleus pulposus prosthesis 120 is machined, polished, cleaned and dried to obtain the intermediate product of the nucleus pulposus prosthesis 120. A microtexture structure 142 is prepared on the outer surface of the intermediate product of the nucleus pulposus prosthesis 120 so that the surface roughness of the nucleus pulposus prosthesis 120 excluding the part of the microtexture structure 142 is Ra≤0.050μm. The third intermediate product of upper endplate 110, the third intermediate product of lower endplate 130, and the intermediate product of nucleus pulposus prosthesis 120 are placed in a tube furnace, and an inert gas with an oxygen mass percentage of 5%-15% at atmospheric pressure is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain upper endplate 110, lower endplate 130, and nucleus pulposus prosthesis 120.

[0035] It should be noted that, as can be seen from the above steps, the structure and performance characteristics of the upper endplate 110 and the lower endplate 130 are optimized through the first intermediate product of the upper endplate 110, the first intermediate product of the lower endplate 130, the second intermediate product of the upper endplate 110, the second intermediate product of the lower endplate 130, the third intermediate product of the upper endplate 110 and the third intermediate product of the lower endplate 130, and finally the prosthesis with the trabecular bone portion and the oxide layer portion.

[0036] Please refer to Figures 1-6 When the inferior endplate 130 and the nucleus pulposus prosthesis 120 are fabricated as a single unit, the detailed steps of the preparation method for the intervertebral disc prosthesis 100 are as follows: The nucleus pulposus prosthesis 120 and the lower endplate 130 are integrally formed into a spherical convex lower endplate 150. Zirconium niobium alloy powder is used as the 3D printing raw material to produce the first intermediate product of the upper endplate 110 and the first intermediate product of the spherical convex lower endplate 150 through 3D printing. The first intermediate product of the upper end plate 110 and the first intermediate product of the spherical convex lower end plate 150 are placed in a hot isostatic pressing furnace. Under the protection of helium or argon, the temperature is raised to 750℃-1100℃, and then kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate 110 and the second intermediate product of the spherical convex lower end plate 150. The second intermediate product of the upper endplate 110 and the second intermediate product of the spherical convex lower endplate 150 are machined, polished, cleaned and dried. A microtexture structure 142 is made on the pit surface of the second intermediate product of the upper endplate 110 to obtain the third intermediate product of the upper endplate 110 and the third intermediate product of the spherical convex lower endplate 150. A microtexture structure 142 is prepared on the outer surface of the intermediate product of the nucleus pulposus prosthesis 120 so that the surface roughness of the nucleus pulposus prosthesis 120 excluding the part of the microtexture structure 142 is Ra≤0.050μm. The third intermediate product of the upper end plate 110 and the third intermediate product of the spherical convex lower end plate 150 are placed in a tube furnace, and an atmospheric pressure inert gas with an oxygen mass percentage of 5%-15% is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain the upper end plate 110 and the spherical convex lower end plate 150.

[0037] In addition to the steps described above, during the fabrication process, when the second intermediate product of the upper end plate 110 is obtained and the third intermediate product of the upper end plate 110 is fabricated using appropriate processes, since the surfaces where the hemispherical groove 113 and the hemispherical convex surface 121 contact each other have a microtexture structure 142, it is also necessary to fabricate a microtexture structure 142 on the surface of the hemispherical groove 113 of the upper end plate 110 and the surface of the hemispherical convex surface 121 of the nucleus pulposus prosthesis 120. Specifically, the microtexture structure 142 is configured to be prepared by using micro-milling, turning, and laser processing mechanical methods to create micron-scale and / or nano-scale microtextures, and the microtexture structure 142 is a concave or convex microstructure of different shapes on the surface of the zirconium-niobium alloy, or a multi-level scale composite structure. In this embodiment, when fabricating using 3D printing, the particle diameter of the zirconium-niobium alloy powder can be 5-150 micrometers.

[0038] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A disc prosthesis, characterized in that: The intervertebral disc prosthesis includes the superior endplate, the nucleus pulposus prosthesis, and the inferior endplate; The upper end plate includes a first plate body and a first fixing seat connected to the first plate body; a hemispherical groove is provided on the side of the first plate body opposite to the first fixing seat. The lower end plate includes a second plate body and a second fixing seat connected to the second plate body; a connecting slot is provided on the side of the second plate body opposite to the second fixing seat; The nucleus pulposus prosthesis includes a hemispherical convex surface and a base, the hemispherical convex surface being movably fitted with the hemispherical groove, and the base being connected to the connecting slot; The first plate is provided with gradient bone trabeculae on the surface where it connects to the first fixation base and on the surface of the first fixation base. The second plate is provided with gradient bone trabeculae on the surface where it connects to the second fixation base and on the surface of the second fixation base. The surfaces where the hemispherical groove and the hemispherical convex surface contact each other are metal-ceramic interfaces formed by the oxidation of zirconium and niobium surfaces. The surfaces where the hemispherical groove and the hemispherical convex surface contact each other have a microtexture structure. The surface porosity of the surface where the first plate connects to the first fixing base decreases gradually from 80% to 40%; the surface porosity of the surface where the second plate connects to the second fixing base decreases gradually from 80% to 40%. The nucleus pulposus prosthesis is manufactured from a zirconium-niobium alloy forging; the upper endplate and the lower endplate are both manufactured by 3D printing using zirconium-niobium alloy powder; or, the lower endplate is integrally formed with the nucleus pulposus prosthesis as a spherical convex lower endplate, and both the upper endplate and the spherical convex lower endplate are manufactured by 3D printing using zirconium-niobium alloy powder.

2. A method for preparing an intervertebral disc prosthesis, used to prepare the intervertebral disc prosthesis as described in claim 1, characterized in that, include: Using zirconium-niobium alloy powder as 3D printing raw material, the first intermediate product of the upper end plate and the first intermediate product of the lower end plate are produced by 3D printing to manufacture zirconium-niobium alloy forgings for the nucleus pulposus prosthesis. The first intermediate product of the upper endplate, the first intermediate product of the lower endplate, and the zirconium-niobium alloy forging of the nucleus pulposus prosthesis are processed to obtain the upper endplate, the lower endplate, and the nucleus pulposus prosthesis. Alternatively, the nucleus pulposus prosthesis and the lower endplate are integrally formed into a spherical convex lower endplate, and zirconium-niobium alloy powder is used as the 3D printing raw material to produce the first intermediate product of the upper endplate and the first intermediate product of the spherical convex lower endplate through 3D printing. The upper endplate first intermediate product and the spherical convex lower endplate first intermediate product are processed to obtain the upper endplate and the spherical convex lower endplate.

3. The method for preparing an intervertebral disc prosthesis according to claim 2, characterized in that: The step of processing the first intermediate product of the upper endplate, the first intermediate product of the lower endplate, and the zirconium-niobium alloy forging of the nucleus pulposus prosthesis to obtain the upper endplate, the lower endplate, and the nucleus pulposus prosthesis includes: The first intermediate product of the upper end plate and the first intermediate product of the lower end plate are placed in a hot isostatic pressing furnace, heated to 750℃-1100℃ under helium or argon protection, and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate and the second intermediate product of the lower end plate. The upper endplate second intermediate product and the lower endplate second intermediate product are machined, polished, cleaned and dried. A microtextured structure is made on the pit surface of the upper endplate second intermediate product to obtain the upper endplate third intermediate product and the lower endplate third intermediate product. The nucleus pulposus prosthesis zirconium-niobium alloy forging is machined, polished, cleaned and dried to obtain the nucleus pulposus prosthesis intermediate product. A microtextured structure is prepared on the outer surface of the nucleus pulposus prosthesis intermediate product so that the surface roughness of the nucleus pulposus prosthesis except for the microtextured structure part is Ra≤0.050μm. The upper endplate third intermediate product, the lower endplate third intermediate product, and the nucleus pulposus prosthesis intermediate product are placed in a tube furnace, and an inert gas with an oxygen mass percentage of 5%-15% at atmospheric pressure is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain the upper endplate, the lower endplate, and the nucleus pulposus prosthesis.

4. The method for preparing an intervertebral disc prosthesis according to claim 2, characterized in that: The step of processing the first intermediate product of the upper endplate and the first intermediate product of the spherical convex lower endplate to obtain the upper endplate and the spherical convex lower endplate includes: The first intermediate product of the upper end plate and the first intermediate product of the spherical convex lower end plate are placed in a hot isostatic pressing furnace, heated to 750℃-1100℃ under helium or argon protection, and kept at 120MPa-180MPa for 1h-3h. The pressure is then reduced to normal, and the furnace is cooled to below 250℃ to obtain the second intermediate product of the upper end plate and the second intermediate product of the spherical convex lower end plate. The upper endplate second intermediate product and the spherical convex lower endplate second intermediate product are machined, polished, cleaned and dried. A microtextured structure is fabricated on the pit surface of the upper endplate second intermediate product to obtain the upper endplate third intermediate product and the spherical convex lower endplate third intermediate product. A microtextured structure is prepared on the outer surface of the nucleus pulposus prosthesis intermediate product so that the surface roughness of the nucleus pulposus prosthesis, excluding the microtextured structure portion, is Ra≤0.050μm. The upper endplate third intermediate product and the spherical convex lower endplate third intermediate product are placed in a tube furnace, and an atmospheric pressure inert gas with an oxygen mass percentage of 5%-15% is introduced. The furnace is heated to 500℃-700℃ at 5℃ / min-20℃ / min, cooled to 400℃-495℃ at 0.4℃ / min-0.9℃ / min, and then naturally cooled to below 50℃ before being removed to obtain the upper endplate and the spherical convex lower endplate.

5. The method for preparing an intervertebral disc prosthesis according to claim 3 or 4, characterized in that: The microtexture structure is configured to be prepared by using micro-milling, turning and laser processing mechanical methods to produce micron-scale and / or nano-scale microtextures, and the microtexture structure is a concave or convex microstructure of different shapes on the surface of zirconium-niobium alloy, or a multi-level scale composite structure.

6. The method for preparing an intervertebral disc prosthesis according to claim 2, characterized in that: The particle diameter of zirconium-niobium alloy powder is 5-150 micrometers.

Images