A 3D printed bionic artificial intervertebral joint prosthesis

Abstract

An embodiment of the present invention discloses a 3D printed bionic artificial intervertebral joint prosthesis, which includes an artificial intervertebral disc, an artificial vertebral body implant prosthesis, a surface porous structure, and a first mounting plate. The artificial intervertebral disc includes an artificial annulus fibrosus in contact with the end plate of the first vertebral body and a first mounting plate combined with the artificial vertebral body. The artificial vertebral body implant prosthesis includes a mounting seat fixed to the artificial intervertebral disc and an implant vertebral body fixed to the lower vertebral body. The implant vertebral body realizes the replacement of the osteotomized part and the fixation with the second vertebral body. The cooperation between the first mounting plate and the mounting seat completes the fixation of the artificial intervertebral disc. The contact between the artificial intervertebral disc and the first mounting plate realizes the movement of the bionic artificial intervertebral joint prosthesis. The present invention can deal with the situation where osteotomy is required for partial vertebral body injury or lesion, making a breakthrough in the current treatment methods limited to cervical intervertebral discs, and effectively solving the problems of narrow indication range of the prosthesis and prosthesis subsidence and insufficient mobility after surgery in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of orthopedic surgical implants, and particularly to a 3D printed bionic artificial intervertebral joint prosthesis. Background Art

[0002] Total disc replacement (TDR) is a new method for treating disc degenerative diseases in recent years and has been clinically applied since the 1980s. It not only removes the diseased intervertebral disc, but also restores the stability and movement function of the vertebral body at this segment. In theory, it can avoid the accelerated degeneration of adjacent segments caused by spinal fusion surgery.

[0003] Since the 1960s, people have started to design artificial cervical disc prostheses, and the material selection and design have been continuously optimized.

[0004] Total disc replacement is mainly used to treat disc degenerative diseases such as discogenic low back pain.

[0005] In recent years, the research and application of artificial intervertebral discs have been carried out at home and abroad. The purpose is to achieve the effects of decompression and fixation fusion of the human intervertebral disc resection, prevent the degeneration of adjacent segments, and at the same time maintain the physiological range of motion of the spine.

[0006] Although total disc replacement, as one of the treatment options for spinal degenerative diseases, has many unique advantages, some objectively existing defects also limit its wide application. As a powerful supplement to personalized orthopedic treatment, 3D printed implants are the result of the integration of multiple disciplines and the trend of medical development. As a metal material 3D printing technology that has gradually matured in recent years, the whole world is on the same starting line, which is undoubtedly a valuable opportunity for Chinese medicine to catch up and surpass. On February 7, 2018, the 3D printed personalized "artificial vertebral body / intervertebral disc integration" implantation surgery jointly carried out by Huatai 3D and the Department of Spinal Surgery of Nanfang Hospital in cooperation with the Additive Manufacturing Research Center of Monash University led by Academician Wu Xinhua of the Australian Academy of Technological Sciences and Engineering was successfully implemented. In May 2019, the Xi'an Red Cross Hospital successfully performed a 3D printed artificial cervical disc replacement surgery. However, there are defects in its prosthesis design. The prosthesis is a two-piece disc structure fixed to the end plate, the height of the prosthesis is insufficient, and the significance of the spinal motion unit is not fully considered, which is prone to a series of complications, especially heterotopic ossification and prosthesis dislocation.

[0007] In China, total disc replacement has been carried out since the end of 2003, and imported products have been used for many years. At present, all products on the Chinese artificial cervical disc market rely on imports. And currently, there are only treatment means for disc damage and lesions, and there is no effective treatment means for some vertebral body lesions or damages that can preserve some healthy vertebral bodies. Summary of the Invention

[0008] The technical problem to be solved by the embodiments of the present invention is to provide a 3D printed bionic artificial intervertebral joint prosthesis, which can solve the problems in the prior art that the intervertebral disc prosthesis cannot cope with vertebral body lesions, the wear resistance of the prosthesis joint surface cannot be taken into account, the mobility of the intervertebral fusion surgery is insufficient, heterotopic ossification and prosthesis dislocation occur after the intervertebral disc prosthesis surgery, etc. The main difference from other treatment means is that part of the diseased and damaged vertebral body can be resected, part of the healthy vertebral body can be retained, part of the vertebral body and intervertebral disc can be replaced, and the patient's own bone can be preserved to the greatest extent.

[0009] To solve the above technical problems, the embodiments of the present invention provide a 3D printed bionic artificial intervertebral joint prosthesis, which is arranged between an adjacent first vertebral body and an osteotomized second vertebral body, and includes:

[0010] An artificial intervertebral disc (10), including a convex surface of the artificial annulus fibrosus (11), an artificial annulus fibrosus (12), a plurality of holes (13), and a fixing plate (14) with an integral structure. The artificial annulus fibrosus (12) is arranged between the convex surface of the artificial annulus fibrosus (11) and the fixing plate (14), and the holes (13) radially penetrate the artificial annulus fibrosus (12);

[0011] An artificial vertebral body implant prosthesis (20), including a mounting seat (22), screw holes, and a prosthesis main body (25). The mounting seat is arranged on the top surface of the prosthesis main body. The fixing plate (14) is fittingly mounted in the mounting seat. The screw holes are arranged in the prosthesis main body (25), and the prosthesis main body (25) is used to be installed inside the osteotomized second vertebral body to replace the resected part;

[0012] A surface porous structure (30), which is arranged on the surface of the prosthesis main body (25);

[0013] A first mounting plate (40), including spines (41) for fixing with the end plate of the first vertebral body, an upper contact surface (42) in contact with the end plate of the first vertebral body, a lower concave surface (43) cooperating with the convex surface of the artificial annulus fibrosus (11), and a lower surface (44) of the first mounting plate for providing the movement angle of the prosthesis.

[0014] Wherein, the fixing plate (14) and the mounting seat (22) are connected by a super semi-circular fit.

[0015] Wherein, the artificial annulus fibrosus (12) is in contact with the end plate of the first vertebral body and performs the function of the human annulus fibrosus.

[0016] Wherein, the number of the spines (41) is at least one, and is used for fixedly connecting with the upper end plate.

[0017] Among them, the lower surface (44) of the first mounting disc is an 8° arc surface.

[0018] Among them, the number of the screw holes is two, and intraoperative fixation is carried out by driving pedicle screws into cancellous bone.

[0019] Among them, the central axes of the two screw holes are skew in space.

[0020] Among them, the material used for the artificial intervertebral disc (10) is ultra-high molecular weight polyethylene, and the material used for the artificial vertebral body implant prosthesis (20) is Ti6Al4V-ELI.

[0021] Among them, the porous structure (30) is 3D printed on the surface of the prosthesis main body (25) by SLM technology.

[0022] Implementing the embodiments of the present invention has the following beneficial effects: For the artificial intervertebral disc of the present invention, different working states of the upper and lower surfaces have different performance requirements. The upper surface in contact with the endplate has higher requirements for elasticity and wear resistance, and the lower surface participates in fixation and has greater stiffness than the upper surface. Using SLM technology can give full play to the advantages of additive manufacturing's complex forming gradient printing, making the internal and external structures of the prosthesis change in a gradient manner, which can adapt to different needs of different parts. The above structures and features maximize the advantages of additive manufacturing, and according to the conditions of different patients, osteotomy is performed, and 3D printing bionic artificial cervical intervertebral joint prostheses are customized according to the osteotomy range, which can expand the indications to various osteotomy diseases of the entire vertebral body, and can solve problems such as prosthesis degradation and displacement after implantation, and can provide better mobility for patients. Description of the Drawings

[0023] Figure 1 Shows a schematic structural view of an embodiment of a 3D printed bionic artificial intervertebral joint prosthesis according to the present invention;

[0024] Figure 2 Shows Figure 1 A schematic semi-sectional view after installation;

[0025] Figure 3 Shows Figure 1 A top view of the first mounting disc of;

[0026] Figure 4 Shows Figure 1 A front view of the first mounting disc of;

[0027] Figure 5 Shows Figure 1 A front view of the artificial annulus fibrosus of;

[0028] Figure 6 Shows Figure 1Top view schematic diagram of the artificial annulus fibrosus;

[0029] Figure 7 Shows Figure 1 Schematic diagram of the artificial vertebral body implant prosthesis;

[0030] Figure 8 Shows Figure 1 Semi-sectional schematic diagram of the artificial vertebral body implant prosthesis;

[0031] Among them, the above-mentioned drawings include the following reference numerals:

[0032] 10. Artificial intervertebral disc; 11. Upper convex surface of the artificial annulus fibrosus; 12. Artificial annulus fibrosus; 13. Twelve groups of holes; 14. Fixed plate; 20. Artificial vertebral body implant prosthesis; 22. Mounting seat; 23. First screw hole; 24. Second screw hole; 25. Prosthesis main body; 30. Surface porous structure; 40. First mounting plate; 41. Spines; 42. Upper contact surface; 43. Lower concave surface; 44. Lower surface of the first mounting plate. Detailed implementation manners

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The examples given are only for explaining the present invention and are not used to limit the scope of the present invention. The present invention will be described more specifically by way of example in the following paragraphs with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise scales, and are only used to facilitate and clearly assist in explaining the objectives of the embodiments of the present invention.

[0035] It should be noted that when a component is referred to as "fixed to" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0037] A 3D printing bionic artificial intervertebral joint prosthesis of the present invention is disposed between an adjacent first vertebral body and a second vertebral body. After removing a part of the diseased and damaged vertebral body of the first vertebral body, this prosthesis is implanted.

[0038] Figure 1 The structural schematic diagram of an embodiment of an intervertebral disc prosthesis according to the present invention is shown, as Figure 1 to Figure 2 As shown, a 3D printing bionic artificial intervertebral joint prosthesis of an embodiment of the present invention includes an artificial intervertebral disc (10), an artificial vertebral body implant prosthesis (20), a surface porous structure (30), and a first mounting plate (40).

[0039] The artificial intervertebral disc (10) includes an artificial annulus fibrosus upper convex surface (11) in contact with the first mounting plate (40), a fixing plate (14) for preventing annulus fibrosus dislocation, an artificial annulus fibrosus (12), and twelve groups of holes (13) thereon.

[0040] The artificial vertebral body implant prosthesis (20) includes a mounting seat (22) for combining with the fixing plate (14) to fix the artificial annulus fibrosus, a first screw hole (23), a second screw hole (24), and a prosthesis main body (25) in contact with the osteotomized second vertebral body. The artificial intervertebral disc (10) cooperates with the first mounting plate (40) to complete the movement of the intervertebral joint prosthesis. The first mounting plate (40) is fixed to the first vertebral body endplate, and the shedding is prevented by the spines (41), and the treated upper contact surface (42) is combined and fixed with the first vertebral body bone.

[0041] The first mounting plate (40) includes spines (41) for fixing to the first vertebral body endplate, an upper contact surface (42) in contact with the first vertebral body endplate, a lower concave surface (43) for cooperating with the artificial annulus fibrosus upper convex surface (11), and a lower surface (44) of the first mounting plate for providing the movement angle of the prosthesis.

[0042] It should be noted that the "movement of the intervertebral joint prosthesis" mentioned here refers to the rotational and translational movements made by the intervertebral joint prosthesis imitating the biological intervertebral joint. As Figure 1For the spatial coordinate system shown, assuming that the artificial intervertebral disc (10), the artificial vertebral body implant prosthesis (20), the first mounting disc (40), the first vertebral body and the second vertebral body are arranged along the Z-axis direction, the intervertebral joint prosthesis of this embodiment can perform rotational, bending and torsional activities relative to the Z-axis, as well as translational movements along the X-axis and / or Y-axis. Additionally, under the condition that the artificial intervertebral disc (10) and the artificial vertebral body implant prosthesis (20) are not separated, the end plate of the first vertebral body and the intervertebral joint prosthesis of this embodiment can also perform relative translation and rotation along the Z-axis direction within a certain range.

[0043] In addition, in order to facilitate the description of the movement dimensions of the intervertebral joint, the above spatial coordinate system is established. The movement range of the intervertebral joint prosthesis of this embodiment is not limited to simple translational and rotational movements along the axis, and can also complete complex movements with multi-dimensional superposition in the three-dimensional space.

[0044] Applying the technical solution of this embodiment, the artificial intervertebral disc (10) is divided into the convex surface of the artificial annulus fibrosus (11) that cooperates with the first mounting disc (40) and the fixing disc (14) that cooperates with the artificial vertebral body implant prosthesis (20) according to the different working states of its upper and lower surfaces, and different surface treatment methods are respectively adopted to maximize the satisfaction of their respective application environments. Similarly, the mounting seat (22) of the artificial vertebral body implant prosthesis (20) and the surface porous structure (30) adopt different structures and post-treatment methods to maximize the satisfaction of their respective application environments. The above structure maximally solves the problems of single material, single structure of the current intervertebral disc prosthesis, and poor implantation effect and serious postoperative failure caused by the prosthesis combination defect.

[0045] Specifically, for the working state where the surface porous structure (30) of the artificial vertebral body implant prosthesis (20) needs to be firmly linked with the second vertebral body and remain relatively stationary, and the working state where the artificial intervertebral disc (10) needs to move relative to the first vertebral body and generate friction, the bone ingrowth ability of the material used for the surface porous structure (30) in this embodiment, and the wear resistance of the material used for the artificial vertebral body implant prosthesis (20) are better than those of the first mounting disc (40).

[0046] As Figure 2 shown, the surface of the artificial vertebral body implant prosthesis (20) with a thickness of 0.5 mm is lightened to form a recess for accommodating the surface porous structure (30), and the recess satisfies that when 3D printed by the SLM technology in this recess, the surface porous structure (30) is just flush with the surface of the artificial vertebral body implant prosthesis (20).

[0047] Specifically, for the surface porous structure (30) of the artificial cone implant prosthesis (20), it needs to be firmly linked to the second cone and maintain a relatively stationary working state. The surface porous structure (30) adopts a porous structure, and the porosity and arrangement are designed according to the most suitable for bone ingrowth, with good osteocyte adhesion and biological activity.

[0048] Briefly, the bone ingrowth ability (or bone integration ability, etc.) here refers to the binding ability between bone tissue and the implant. After the 3D-printed bionic artificial intervertebral joint prosthesis is implanted into the human body, the cells on the surface where the vertebral body contacts the intervertebral disc prosthesis can differentiate into new bone after being stimulated. Depending on the materials and structures, different intervertebral joint prostheses have different abilities to stimulate and accept new bone formation. The surface porous structure (30) of the artificial cone implant prosthesis (20) in this embodiment all adopts materials with higher bone ingrowth ability to improve the compatibility and connection strength between the intervertebral joint prosthesis and the second vertebral body.

[0049] In other embodiments not shown in the figure, the wear resistance can also be improved by adding a coating on the surface of the surface porous structure (30) of the artificial cone implant prosthesis (20), and the bone ingrowth ability can be improved by performing surface treatment of hydroxyapatite on the surface porous structure (30).

[0050] Preferably, the artificial cone implant prosthesis (20), the first mounting plate (40), and the surface porous structure (30) are preferably made of titanium alloy, and the artificial intervertebral disc (10) is preferably made of high molecular weight polyethylene. Titanium has good "biocompatibility", has good corrosion resistance to body fluids, secretions, etc. in the living body, and can adapt to common sterilization methods, and is suitable for places in contact with the bone or muscle fibers of the organism. Polyethylene has good chemical stability, is non-toxic, odorless, and has a low water absorption rate, less than 0.01%.

[0051] The material used for the artificial intervertebral disc (10) is ultra-high molecular weight polyethylene, and the material used for the artificial vertebral body implant prosthesis (20) is Ti6Al4V-ELI.

[0052] As Figure 1 to Figure 8 shown, the artificial cervical disc of this embodiment includes an upper convex surface (11) in contact with the first mounting plate and a fixing plate (14) for preventing the annulus fibrosus from dislocating. The lower surface is a flat surface, and the upper surface is a curved surface in contact with the end plate of the first vertebral body. The convex part of the curved surface cooperates with the concave surface of the first mounting plate.

[0053] The fixing plate for fixing on the artificial intervertebral disc is a disc-shaped structure with a maximum diameter of 9 mm and a minimum diameter of 8 mm.

[0054] As Figure 1 to Figure 8As shown in the figure, the size of the artificial cone in this embodiment is selected such that the bottom diameter of the vertebral prosthesis at the thinnest position is 7 mm, and the top diameter of the vertebral body at the thickest position is 12 mm, and the size matches that of the human cervical vertebra.

[0055] Furthermore, Figure 1 to Figure 8 in, the sizes of the artificial intervertebral disc (10), the artificial vertebral body implant prosthesis (20), and the surface porous structure (30) can all be modified according to the actual situation of the patient.

[0056] Furthermore, for the fixation of the prosthesis during the operation, it is fixed with 3.5 mm pedicle screws through the first screw hole (23) and the second screw hole (24) of the artificial vertebral body. After the operation, as bone ingrowth occurs, the fixation function of the screw holes and the pedicle screws is gradually replaced.

[0057] The two threaded holes on the artificial vertebral body implant prosthesis form angles of +20° and -20° with the horizontal plane respectively, and the included angle of the projections of the two threaded holes on the horizontal plane is 60°, and they are in a skew state in space. The structure with an 8° inclination angle on the lower surface of the first mounting plate allows the bending and torsion movement range of this cervical intervertebral joint prosthesis to be ±8°.

[0058] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0059] The artificial intervertebral disc forms an artificial fiber ring that cooperates with the first vertebral endplate and a fixing plate that is fixed to the artificial vertebral body prosthesis for its two different working states on its upper and lower surfaces respectively. The outer surface of the artificial vertebral body implant prosthesis adopts a porous structure to achieve better bone ingrowth with the bone. The artificial vertebral body implant prosthesis uses titanium alloy, and the artificial intervertebral disc uses polyethylene, giving full play to the advantages of each material to avoid their disadvantages. The porous structure and the solid structure change in a gradient manner to adapt to the different properties of different positions of the human vertebral body bones. The titanium alloy material is integrally manufactured using the SLM technology. It greatly solves the problems of poor effect and short maintenance time after the current intervertebral disc prosthesis is implanted into the organism, expands the surgical indications, and improves the forming quality, complexity, and precision of the artificial prosthesis.

[0060] The above is only a preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention; any ordinary technical personnel in this industry can smoothly implement the present invention according to the instructions in the drawings and the above description; however, any minor changes, modifications, and equivalent variations made by those skilled in the art without departing from the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and variations made to the above embodiments based on the essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A 3D-printed bionic artificial intervertebral joint prosthesis is disposed between an adjacent first vertebra and an osteotomized second vertebra, and is characterized in that Comprising: An artificial intervertebral disc (10), including an upper convex surface (11) of an artificial annulus fibrosus with an integral structure, an artificial annulus fibrosus (12), a plurality of holes (13), and a fixing plate (14). The artificial annulus fibrosus (12) is disposed between the upper convex surface (11) of the artificial annulus fibrosus and the fixing plate (14), and the holes (13) radially penetrate through the artificial annulus fibrosus (12); An artificial vertebral body implant prosthesis (20), including a mounting seat (22), screw holes, and a prosthesis main body (25). The mounting seat is disposed on the top surface of the prosthesis main body. The fixing plate (14) is fittingly mounted in the mounting seat. The screw holes are disposed in the prosthesis main body (25), and the prosthesis main body (25) is used to be mounted inside the osteotomized second vertebral body to replace the truncated part; A surface porous structure (30), disposed on the surface of the prosthesis main body (25); A first mounting plate (40), including spines (41) for fixing to the first vertebral endplate, an upper contact surface (42) contacting the first vertebral endplate, a lower concave surface (43) cooperating with the upper convex surface (11) of the artificial annulus fibrosus, and a lower surface (44) of the first mounting plate providing the movement angle of the prosthesis; The artificial annulus fibrosus (12) contacts the endplate of the first vertebral body and performs the function of the human annulus fibrosus.

2. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 1, wherein The fixing plate (14) and the mounting seat (22) are connected by a super semi-circular fit.

3. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 1, characterized in that The number of the spines (41) is at least one and is used for fixedly connecting to the upper endplate.

4. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 3, characterized in that The lower surface (44) of the first mounting plate is an 8° arc surface.

5. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 1, characterized in that, The number of the screw holes is two, and intraoperative fixation is performed by driving pedicle screws into the cancellous bone.

6. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 5, characterized in that, The central axes of the two screw holes are skew in space.

7. The 3D printed bionic artificial intervertebral joint prosthesis according to any one of claims 1-6, characterized in that The material used for the artificial intervertebral disc (10) is ultra-high molecular weight polyethylene, and the material used for the artificial vertebral body implant prosthesis (20) is Ti6Al4V-ELI.

8. The 3D printed bionic artificial intervertebral joint prosthesis according to claim 7, characterized in that, The porous structure (30) is 3D printed on the surface of the prosthesis main body (25) by SLM technology.

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