A 3D printed bionic vertebral semi-joint

Abstract

The present invention discloses a 3D printed bionic vertebral semi-joint, comprising a prosthesis body, a conical knob, and a spreader rod, wherein the top surface of the prosthesis body is provided with an integrally formed upper convex surface, the prosthesis body is used to implant the cut-off part of the lower vertebra of the human body, and the upper convex surface is closely fitted with the upper vertebra of the human body, the prosthesis body is provided with a knob hole, the conical knob is screwed into the knob hole, the side wall of the prosthesis body is provided with a guide hole connected with the knob hole, the spreader rod is slidably inserted into the guide hole, and the end of the spreader rod is abutted against the peripheral wall of the conical knob, and the spreader rod is pushed to slide along the guide hole by rotating the conical knob, so that the other end of the spreader rod is against the lower vertebra of the human body. The present invention has a simple structure, does not require multiple assembly, has low cost, improves the movement strength and firmness of the bionic cervical intervertebral joint, and improves the success rate of the operation.

Description

Technical Field

[0001] The present invention relates to the technical field of medical prostheses, and particularly to a 3D printed bionic vertebral hemijoint. Background Art

[0002] The incidence rate of cervical spine diseases has been increasing year by year and tends to be younger. Artificial disc replacement is one of the commonly used treatment options. However, traditional artificial disc prostheses have problems such as a cumbersome product structure, a single size selection, and inability to be adjusted according to each patient; poor anti-fatigue and anti-wear performance of the product, and extremely poor biocompatibility with the original vertebral tissue, resulting in problems such as the shedding of artificial prostheses. 3D printing technology is a kind of rapid prototyping technology. It is a technology that constructs objects by layer-by-layer stacking using powdered metals or plastics and other bondable materials based on a digital model. Therefore, it can print many complex structures. The bionic cervical intervertebral joint based on 3D printing can be well combined with the patient's vertebrae and can almost meet the personalized needs of all patients. However, the related 3D printed bionic vertebral body design structure is still relatively complex and has pain points that are not conducive to large-scale production and surgical operations.

[0003] For example, most existing bionic vertebral bodies use multi-component prostheses. The multi-component prosthesis includes an upper endplate, a nucleus pulposus, and a lower endplate. The lower surface of the upper endplate and the upper surface of the nucleus pulposus form a ball-and-socket joint. The lower surface of the nucleus pulposus is attached to the upper surface of the lower endplate. The ball-and-socket joint is composed of a spherical groove formed on the lower surface of the upper endplate and a spherical dome protruding from the upper surface of the nucleus pulposus, enabling the upper endplate to achieve six-degree-of-freedom movement in the directions of flexion / extension, left / right lateral bending, and left / right rotation relative to the nucleus pulposus, and enabling the nucleus pulposus to move in the front, rear, left, and right directions and rotate around the central axis on the upper surface of the lower endplate, and it is not easy to prolapse. However, this structure usually has problems such as prosthesis collapse, nucleus pulposus leakage, and reduced mobility, resulting in difficulty in the long-term stable use of artificial disc prostheses and the need for regular replacement. And the second operation will bring double losses to the patient in terms of health and economy. In addition, the fixation of the upper endplate and the lower endplate of some multi-component prostheses to the human vertebrae mostly uses screws for cross-connection fixation, which not only makes the prosthesis implantation more cumbersome but also easily causes secondary damage to the patient. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a 3D printed bionic vertebral hemijoint, which has a simple structure, does not require multiple assemblies, has a low cost, improves the movement intensity and firmness of the bionic cervical intervertebral joint, and at the same time improves the success rate of the operation.

[0005] To achieve the above-mentioned purpose, the present invention discloses a 3D printed bionic vertebral half-joint, comprising a prosthesis body, a conical knob, and a spreader rod, wherein the top surface of the prosthesis body is provided with an integrally formed upper convex surface, the prosthesis body is used to implant the cut-off part of the lower vertebra of the human body, and the upper convex surface is tightly fitted with the upper vertebra of the human body, a knob hole is provided on the prosthesis body, the conical knob is screwed into the knob hole, a guide hole connected to the knob hole is provided on the side wall of the prosthesis body, the spreader rod is slidably inserted into the guide hole, and the end of the spreader rod is abutted against the peripheral wall of the conical knob, and the spreader rod is pushed to slide along the guide hole by rotating the conical knob so that the other end of the spreader rod is against the lower vertebra of the human body.

[0006] Furthermore, the knob hole includes a tapered portion and a threaded portion, the tapered portion is arranged at the front end of the prosthesis body and is connected to the guide hole, and the threaded portion is arranged at the rear end of the tapered portion.

[0007] Furthermore, the conical knob includes a conical head and a screw, the screw is threadedly connected to the threaded portion, the conical head is screwed into the conical portion, and the end of the expansion rod has a recess matching the conical head, so that the expansion rod slides toward both sides under the rotational force of the conical head.

[0008] Furthermore, a guide groove is provided on the inner wall of the guide hole, and a guide block slidably matched with the guide groove is provided on the peripheral wall of the expansion rod, thereby ensuring that the expansion rod slides more stably in the guide groove, avoiding deflection, and ensuring the stability of the fixation of the prosthesis body.

[0009] Furthermore, the surface of the prosthesis body has a porous structure through 3D printing, and the thickness of the porous structure is 0.3mm-1mm. Therefore, the porous structure is 3D printed on the surface of the prosthesis body using SLM technology, so that the prosthesis body as a whole is a solid structure, which is beneficial to bone fusion and ensures the strength of the bionic cervical intervertebral joint.

[0010] Furthermore, the diameter of the upper end of the prosthesis body is 13mm-16mm, and the diameter of the lower end of the prosthesis body is 6mm-8mm.

[0011] Furthermore, first planes are arranged on both sides of the upper part of the prosthesis body, and a second plane is arranged on the rear side of the prosthesis body, so that the prosthesis body can better match and fuse with the lower vertebrae of the human body, and the prosthesis body is not easily displaced after implantation.

[0012] Furthermore, the diameter of the upper convex surface is greater than the diameter of the prosthesis body, and can cooperate with the patient's vertebrae to play a stabilizing role.

[0013] Furthermore, the surface of the porous structure is coated with a coating, thereby increasing the wear resistance of the porous structure and improving its bone fusion ability by adding the coating.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The prosthesis of the present invention adopts an integrated design and does not require assembly. After the prosthesis is implanted in the lower vertebra of the human body, the upper convex surface on the prosthesis fits tightly with the upper vertebra of the human body, thereby realizing multi-degree-of-freedom twisting and tilting movements. This not only greatly simplifies the structure of the prosthesis and reduces production costs, but also facilitates large-scale production. (2) The present invention uses a conical knob as a force point to push the expansion rod to expand horizontally to the left and right, so that the expansion rod supports the lower vertebra of the human body, thereby fixing the prosthesis on the lower vertebra of the human body. Compared with the traditional screw fixing method, the horizontal expansion fixing method of the present invention is simpler, avoids secondary damage to the patient, and greatly improves the success rate of the operation. (3) The end surface is a porous structure with customizable thickness, and the interior is a solid structure, which is beneficial to bone fusion and ensures the strength of the prosthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the overall structural front view of the present invention;

[0017] Figure 2 It is a structural schematic diagram of the knob hole;

[0018] Figure 3 It is a schematic diagram of the structure of the knob hole and the guide hole;

[0019] Figure 4 It is a side view of the overall structure of the present invention;

[0020] Figure 5 It is a half-section diagram of the overall structure of the present invention;

[0021] Figure 6 It is a schematic diagram of the overall structure of the tapered knob;

[0022] Figure 7 The main view of the overall structure of the prosthesis body implanted into the human vertebra;

[0023] Figure 8 A side view of the overall structure of the prosthesis body implanted into the human vertebra. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Reference Figures 1-3As shown, a 3D-printed bionic vertebral semi-joint includes a prosthesis main body 1, a conical knob 2, and a spreading rod 3. The top surface of the prosthesis main body 1 is provided with an integrally formed upper convex surface 4, and the upper convex surface 4 is in the shape of a hemisphere as a whole. In this embodiment, osteotomy is performed according to the conditions of different patients (taking the lower vertebrae of the human body as an example here), and the prosthesis main body 1 is 3D-printed customized according to the scope of osteotomy, and then the prosthesis main body 1 is implanted into the part of the lower vertebra C1 of the human body that has been removed, and the upper convex surface 4 is in close contact with the upper vertebra C2 of the human body (such as Figure 7 , Figure 8 shown). The diameter of the upper convex surface 4 is larger than the diameter of the prosthesis main body 1, so that it can cooperate with the upper vertebra of the human body, and can realize multi-free-angle twisting and tilting movements. In order to ensure the stability of the prosthesis main body 1, a knob hole 11 is opened on the prosthesis main body 1, and the conical knob 2 is screwed into the knob hole 11. A guide hole 12 communicating with the knob hole 11 is opened on the side wall of the prosthesis main body 1. The spreading rods 3 are a pair and are respectively slidably inserted into the guide holes 12, and the ends of the spreading rods 3 are in abutting cooperation with the peripheral wall of the conical knob 2. By rotating the conical knob 2, the spreading rods 3 are pushed to slide along the guide holes 12, so that the other ends of the spreading rods 3 abut against the lower vertebra of the human body, thus playing a stabilizing role.

[0026] Furthermore, it is noted that in this embodiment, the material of the prosthesis main body 1 is preferably Ti6Al4V-ELI. The upper end diameter of the prosthesis main body 1 is 13 mm - 16 mm, and the lower end diameter of the prosthesis main body 1 is 6 mm - 8 mm, so that the prosthesis main body 1 is larger at the top and smaller at the bottom as a whole, making the prosthesis main body 1 match the lower vertebra of the human body, and the overall size can be modified according to the actual situation of the patient.

[0027] Referring to Figure 3 , Figure 6 shown, specifically, the knob hole 11 includes a conical part 111 and a threaded part 112. The conical part 111 is arranged at the front end of the prosthesis main body 1 and communicates with the guide hole 12. The threaded part 112 is arranged at the rear end of the conical part 111, and in this embodiment, the threaded part 112 does not penetrate through the rear end of the prosthesis main body 1. The conical knob 2 includes an integrally formed conical head 21 and a screw rod 22. The screw rod 22 is threadedly connected to the threaded part 112, and the conical head 21 is screwed into the conical part 111. Therefore, when the screw rod 22 of the conical knob 2 is screwed into the threaded part 112, the conical head 21 advances along the conical part 111.

[0028] Referring to Figure 2 , Figure 4 , Figure 5As shown, further, the end of the spreader rod 3 has a recess 31 that matches the conical head 21, so that after the conical knob 2 is screwed into the knob hole 11, the spreader rod 3 is pushed to the left and right sides by the rotational force of the conical portion 111 of the conical knob 2, until the other end of the spreader rod 3 is against the lower vertebra of the human body and is locked with the conical knob 2 to form a fixation, thereby fixing the prosthesis body 1 to the upper vertebra of the human body by means of horizontal spreading. This fixing method is simpler than traditional screw fixation and can be fixed without making a hole in the lower vertebra of the human body.

[0029] Reference Figure 1 , Figure 4 As shown, more preferably, in order to prevent the prosthesis body 1 from being displaced after being expanded and fixed on the lower vertebra C1 of the human body, a first plane 13 is provided on both sides of the upper part of the prosthesis body 1 in this embodiment, and a second plane 14 is provided on the rear side of the prosthesis body 1, so that the first plane 13 and the second plane 14 can better fit with the surface of the lower vertebra C1 of the human body, and the mutual constraint between the surfaces is utilized to limit the displacement of the prosthesis body 1 after implantation, thereby greatly improving the stability of the prosthesis body 1 after implantation.

[0030] Reference Figure 2 , Figure 4 As shown, further, a guide groove 121 is provided on the inner wall of the guide hole 12, and a guide block slidably matched with the guide groove 121 is provided on the peripheral wall of the expansion rod 3 to prevent the expansion rod 3 from rotating in the guide groove 121 during horizontal movement, thereby ensuring the stability of the expansion rod 3.

[0031] Specifically, in this embodiment, the conical knob 2 and the spreader rod 3 are manufactured by 3D printing technology according to the size and shape of the knob hole 11 and the guide hole 12 of the prosthesis body 1, and the material of the conical knob 2 and the spreader rod 3 is preferably Ti6Al4V-ELI, thereby ensuring the strength of the conical knob 2 and the spreader rod 3, making the connection between the prosthesis body 1 and the lower vertebra of the human body more secure.

[0032] Reference Figure 1 , Figure 5 As shown, in this embodiment, after the prosthesis main body 1 is formed by 3D printing, the surface of the prosthesis main body 1 is then 3D printed with a porous structure 5 by SLM technology, so that the prosthesis main body 1 can better match and fuse with the lower vertebrae of the human body, and the prosthesis main body 1 is a solid structure as a whole, which is beneficial to bone fusion and ensures the strength of the bionic cervical intervertebral prosthesis.

[0033] The present embodiment is not limited to printing the porous structure on the surface of the prosthesis body 1 after printing it. The prosthesis body 1 and the porous structure 5 may also be integrally formed. This embodiment will not be repeated here.

[0034] The thickness of the porous structure 5 is 0.3 mm - 1 mm. The thickness of the porous structure can be customized according to the actual situation of the patient. In this embodiment, the thickness is preferably 0.5 mm. The material of the porous structure 5 is preferably titanium alloy. The porosity and pore size are designed based on the most suitable bone fusion ability, so as to have good osteocyte adhesion and biological activity and promote the bone fusion ability.

[0035] Preferably, in this embodiment, a coating can be applied on the surface of the porous structure 5 to improve the wear resistance of the porous structure.

[0036] Of course, the above embodiments are only used to illustrate the technical concept and characteristics of the present invention. The purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly. It cannot be used to limit the protection scope of the present invention. All modifications made according to the spirit of the main technical solution of the present invention should be covered within the protection scope of the present invention.

Claims

1. A 3D printed bionic vertebral half-joint, characterized in that: The invention comprises a prosthesis body (1), a conical knob (2), and two spreader rods (3). The top surface of the prosthesis body (1) is provided with an integrally formed upper convex surface (4). The prosthesis body (1) is used to be implanted in a portion of a lower vertebra of a human body that has been osteotomized, and the upper convex surface (4) is tightly fitted with the upper vertebra of the human body. First planes are provided on the left and right sides of the upper part of the prosthesis body (1), and a second plane is provided on the rear side of the prosthesis body (1), so that the first plane (13) and the second plane (14) are fitted with the surface of the lower vertebra of the human body after osteotomy. The prosthesis body (1) is provided with a knob hole (11). The conical knob (2) is screwed into the knob hole (11); a guide hole (12) connected to the knob hole (11) is formed on the side wall of the prosthesis body (1); the spreader rod (3) is slidably inserted into the guide hole (12), and one end of the two spreader rods (3) is respectively in contact with the peripheral wall of the conical knob (2); the two spreader rods (3) are pushed to slide toward the left and right sides along the guide hole (12) by rotating the conical knob (2), so that the other ends of the two spreader rods (3) are pressed against the lower vertebrae of the human body and locked with the conical knob (2) to form a fixed position; A guide groove (121) is provided on the inner wall of the guide hole (12), and a guide block slidably matched with the guide groove (121) is provided on the peripheral wall of the expansion rod (3).

2. A 3D printed bionic vertebral half-joint according to claim 1, characterized in that: The knob hole (11) comprises a tapered portion (111) and a threaded portion (112); the tapered portion (111) is arranged at the front end of the prosthesis body (1) and is connected to the guide hole (12); the threaded portion (112) is arranged at the rear end of the tapered portion (111).

3. A 3D printed bionic vertebral half-joint according to claim 2, characterized in that: The conical knob (2) comprises a conical head (21) and a screw rod (22), wherein the screw rod (22) is threadedly connected to the threaded portion (112), the conical head (21) is screwed into the conical portion (111), and one end of the two spreading rods (3) has a concave position (31) matching the conical head (21).

4. A 3D printed bionic vertebral half-joint according to claim 1, characterized in that: The surface of the prosthesis body (1) is provided with a porous structure (5) by 3D printing, and the thickness of the porous structure (5) is 0.3 mm-1 mm.

5. The 3D printed bionic vertebral half-joint according to claim 1, characterized in that: The diameter of the upper end of the prosthesis main body (1) is 13 mm to 16 mm, and the diameter of the lower end of the prosthesis main body (1) is 6 mm to 8 mm.

6. The 3D printed bionic vertebral half-joint according to claim 1, characterized in that: The diameter of the upper convex surface (4) is greater than the diameter of the prosthesis body (1).

7. A 3D printed bionic vertebral half-joint according to claim 4, characterized in that: The surface of the porous structure (5) is coated with a plating layer.

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