CN115886961A - A 3D printing-based anterior cervical fixation system - Google Patents

Abstract

The application discloses a 3D printing-based anterior cervical spine fixation system, which includes a main body of a fixing plate and a fixing screw. The main body of the fixing plate is fixedly connected with the vertebral body through the fixing screw. The contact surface, the vertebral body contact surface and the tissue contact surface are not parallel to each other. Preferably, the vertebral body contact surface and the tissue contact surface are both curved surfaces, and the curvature radius of the vertebral body contact surface is less than or equal to the curvature radius of the tissue contact surface. The main body of the fixing plate includes a solid part and a loose part, the solid part and the loose part are fixedly connected, the solid part is arranged on the side close to the tissue contact surface, and the loose part is arranged on the side close to the vertebral body contact surface. On the one hand, this application fits better with the vertebral body and generates greater frictional force relative to the vertebral body; on the other hand, the contact surface with the muscle tissue is smoother, reducing frictional force, thus improving the performance of the anterior cervical spine fixation system. Stability and security.

Description

A 3D printing-based anterior cervical fixation system

technical field

This application relates to the field of spinal surgical implants, in particular to a 3D printing-based anterior cervical fixation system.

Background technique

In the treatment of cervical spine tumors, cervical spine fractures and dislocations, and cervical spine deformities, the anterior cervical fixation system is a commonly used surgical implant for fixed connection of adjacent vertebral bodies and reconstruction of cervical spine biomechanical functions.

The anterior cervical fixation system usually consists of a main body of a fixation plate and fixation screws. The main body of the fixing plate extends along the direction of the cervical spine, and the adjacent 2-3 vertebral bodies are fixed to each other by several fixing screws. Since the main body of the fixing plate is additionally attached to the outer surface of the vertebral body, it is equivalent to "thickening" the vertebral body to a certain extent, so it has a certain impact on the esophagus, blood vessels, nerves, and muscle tissues that are originally close to the vertebral body. Especially in the process of peristalsis, the esophagus will produce a large displacement to form friction with the surface of the vertebral body, which will amplify this effect and affect the prognosis of the operation. In order to reduce this effect, it is common practice to make the main body of the fixing plate sufficiently thin. However, the strength of the main body of the fixing plate is limited by the material, and its thickness has a certain limit. If the thickness continues to be reduced under this limit, the stability of the entire fixing system will be affected, resulting in the risk of fracture. Another means of reducing the impact is to improve the fit of the main body of the plate to the surface of the vertebral body. The specific method is usually to pre-bend it at a certain angle when manufacturing the main body of the fixing plate, so that its cross section forms a curve close to the cross-sectional profile of the vertebral body, reducing the gap between the main body of the fixing plate and the vertebral body thereby improving its fit.

However, in the prior art, the main body of the fixing plate is usually a thin metal sheet, and commonly used materials include stainless steel, titanium alloy and the like. Its upper and lower surfaces are roughly parallel, one of which is in contact with the vertebral body, which is the vertebral body contact surface; the other surface is in contact with the muscle tissue, which is the tissue contact surface. After the pre-bending operation is performed on the main body of the fixing plate, the contact surface of the tissue and the contact surface of the vertebral body are simultaneously bent accordingly. Although the vertebral body contact surface is conducive to the fitting of the main body of the fixing plate and the vertebral body after bending, the tissue contact surface becomes "protruding" after bending, which is not conducive to the fitting of the muscle or vascular tissue. Therefore, there is a technical problem in the prior art that the contact surface of the vertebral body and the contact surface of the tissue cannot be combined.

In addition, after the implantation of the anterior cervical fixation system, as time goes by, the fixation screws are displaced by vibration or other reasons, resulting in various forms of failure of the implant. Common failure modes include weak locking, screws protruding from the board, part of the screws falling off, board deflection, etc.

One of the main causes of various displacement failures is that the relative coefficient of friction between the main body of the fixing plate and the vertebral body is insufficient, so that the so-called rough surface formed by the subtractive machining process in the prior art cannot provide sufficient friction. Therefore, a better rough surface is needed to provide sufficient stability.

Therefore, those skilled in the art are committed to developing a 3D printing-based anterior cervical fixation system to solve the technical problems in the prior art.

Contents of the invention

In order to achieve the above purpose, the present application provides a 3D printing-based anterior cervical fixation system, which includes a main body of a fixing plate and fixing screws, and the main body of the fixing plate is fixedly connected to the vertebral body through the fixing screws. It is characterized in that the The main body of the fixing plate includes a vertebral body contact surface and a tissue contact surface, and the vertebral body contact surface and the tissue contact surface are not parallel to each other.

Further, both the vertebral body contacting surface and the tissue contacting surface are curved surfaces, and the curvature radius of the vertebral body contacting surface is smaller than or equal to the curvature radius of the tissue contacting surface.

Further, the main body of the fixing plate includes a solid part and a loose part, the solid part is fixedly connected to the loose part, the solid part is arranged on the side close to the tissue contact surface, and the loose part is arranged on the side close to the tissue contact surface. One side of the contact surface of the vertebral body.

Further, the thickness of the solid part is 2mm-2.4mm, and the thickness of the loose part is 0.1mm-0.3mm.

Further, the loose part is a bone trabecular structure.

Further, the main body of the fixing plate includes a screw hole for accommodating the fixing screw, and the fixing screw passes through the screw hole to realize the fixed connection between the main body of the fixing plate and the vertebral body.

Further, 8 screw holes are included.

Further, the anterior cervical spine fixation system further includes a shielding part, which is detachably connected to the main body of the fixing plate, and the shielding part is used to prevent the fixing screw from passing through or withdrawing from the screw hole.

Further, the main body of the fixing plate further includes a shielding portion accommodating groove for accommodating the shielding portion, and the shielding portion accommodating groove is partially overlapped with the screw hole.

The anterior cervical fixation system based on 3D printing according to claim 9, characterized in that it comprises 4 said shielding part accommodation grooves, each of said shielding part accommodation grooves partially overlaps with 2 said screw holes respectively set up.

Compared with the prior art, the technical solution of the present application at least has the following technical effects:

1. The anterior cervical fixation system based on 3D printing provided by this application, because the curvature radius of the vertebral body contact surface of the main body of the fixation plate is smaller than the curvature radius of the tissue contact surface, it can fit well with the cervical vertebral body At the same time, the surface in contact with the muscle organ tissue is smoother, which can reduce the foreign body sensation caused by relative movement friction.

2. In the anterior cervical fixation system based on 3D printing provided by this application, the main body of the fixation plate is provided with a solid part and a loose part, wherein the solid part has a smoother surface and is in contact with muscle organ tissues, and the loose part has a rougher surface , The coefficient of friction is large, and it is in contact with the vertebral body. When the muscle organs are peristaltic, a small frictional force is brought to the main body of the fixed plate, and at the same time, a large frictional force is generated between the main body of the fixed plate and the vertebral body, thereby enhancing the stability of the anterior cervical fixation system.

The technical solution of the present application combines the good fit between the vertebral body contact surface and the vertebral body with the increase of the friction coefficient, and the smoothness and smoothness of the tissue contact surface relative to the muscle tissue, and finally achieves an increase in the anterior cervical path under the joint action. The technical effect of the stability and safety of the fixing system.

The idea, specific structure and technical effects of the present application will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present application.

Description of drawings

Fig. 1 is a structural representation of an embodiment of the present application;

Fig. 2 is a structural representation of an embodiment of the present application;

Figure 3 is a cross-sectional view of one embodiment of the present application;

Figure 4 is a cross-sectional view of one embodiment of the present application;

Figure 5 is a view of the vertebral body contact surface of one embodiment of the present application.

Detailed ways

The following introduces multiple preferred implementations of the present application with reference to the accompanying drawings, so as to make the technical content clearer and easier to understand. The present application can be embodied in many different forms of implementations, and the protection scope of the application is not limited to the implementations mentioned herein.

Example 1

This embodiment is a 3D printing-based anterior cervical fixation system, which is used to fix and connect adjacent or similar cervical vertebral bodies in anterior cervical surgery. The anterior cervical fixation system includes a multi-segment fixation plate main body 1 and several fixation screws, and the fixation plate main body 1 is attached to the cervical vertebral body through the fixation screws. The number of segments of the fixing plate main body 1 corresponds to the number of fixed vertebral bodies, and usually two fixing screws are driven into each vertebral body. The main body 1 of the fixing plate is made of metal, and is generally in the shape of a rigid sheet, so that the vertebral bodies fixedly connected with it are also fixedly connected with each other.

FIG. 1 and FIG. 2 are structural schematic diagrams of the fixing plate main body 1 used in this embodiment. The main body 1 of the fixing plate is in the shape of a thin metal sheet and is generally long and narrow. It includes a screw hole 11 through which the fixing screw is drilled into the vertebral body, so as to realize the fixed connection between the main body 1 of the fixing plate and the vertebral body. The main body 1 of the fixing plate used in this embodiment has four segments, that is, four adjacent vertebral bodies are connected and fixed, so eight screw holes 11 are provided. It is arranged along the length direction of the fixing plate main body 1, and two screw holes 11 are arranged every about 2 cm.

The fixing plate main body 1 also includes several lightening openings 12 . The weight reducing opening 12 has the effect of reducing weight by hollowing out a part of the fixing plate main body 1 . The number and size of the weight-reducing openings need to be adjusted according to the length, width, thickness of the main body 1 of the fixing plate and the required strength of the patient, so as to reduce the weight of the main body 1 of the fixing plate as much as possible under the premise of ensuring strength and safety. In this embodiment, preferably, two weight-reducing openings 12 are provided. As shown in Figure 1, two weight-reducing openings 12 are arranged symmetrically, respectively located at the upper part and the lower part of the main body 1 of the fixed plate (the position is only described in the orientation of the state placed in the figure, and the technical solution is not limited), so as to balance the Stress distribution caused by hollowing out. The weight-reducing opening 12 is substantially rectangular, and the four corners of the rectangle are arc-shaped. In this embodiment, the size of the weight reducing opening 12 is 10mm-13mm in length and 4mm-6mm in width.

In order to prevent the fixing screw from coming out of the screw hole 11, the anterior cervical fixation system includes a shielding part (not shown in the figure), and the shielding part usually includes two or more shielding arms. The screw holes 11 are shielded to prevent the fixing screws from entering or coming out of the screw holes 11 . Correspondingly, a shielding portion receiving groove 13 is provided on the fixing plate main body 1 . In this embodiment, the shielding portion receiving groove 13 is configured as a substantially circular groove for accommodating the shielding portion and reserving a space for its rotation. As shown in FIG. 1 , the shielding portion accommodating groove 13 is disposed between the two screw holes 11 and partially overlaps with the two screw holes 11 respectively. The blocking arm can block the two fixing screws at the same time by rotating, so as to prevent withdrawal. The screw hole 11 is a circular opening and penetrates through the fixing plate main body 1 from the thickness direction, so the shielding part receiving groove 13 is partially “hollowed out” to form an incomplete circle. In the main body of the four-segment fixing plate of this embodiment, eight screw holes 11 are provided, so four corresponding shielding part accommodation slots 13 are provided, corresponding to four pairs respectively (two screw holes 11 that are close to each other are a pair) ) screw holes 11 for shielding. In other embodiments, the shielding part accommodation groove 13 can also be set to partially overlap with the four screw holes 11, so as to achieve the effect of one shielding part covering the four screw holes 11 at the same time, which can reduce the number of shielding parts. Reduce assembly difficulty and improve stability.

A shielding portion connecting hole 131 is also provided at the center of the shielding portion receiving groove 13 . The shielding portion is rotatably connected to the fixing plate main body 1 through the shielding portion connecting hole 131 . The shielding part receiving groove 13 also includes a limiting part receiving groove 132 . The limiting part receiving groove 132 is used for accommodating the limiting part to limit the rotatable shielding part to a certain extent.

A viewing opening 14 is also provided in the middle of the fixing plate main body 1 . The visible opening 14 is a long and narrow opening extending along the length direction of the fixing plate main body 1 . Filling bone defects with fillers is a common operation in anterior cervical spine-related surgeries. The operator can observe the position and state of the filler through the viewing opening 14 . In this embodiment, the visible opening 14 is substantially rectangular, and the four corners of the rectangle are arc-shaped. In this embodiment, the size of the visible opening 12 is 15mm-20mm in length and 6mm-10mm in width.

Both ends of the fixing plate main body 1 are provided with pre-positioning openings 15 . The pre-positioning opening 15 is incompletely circular to accommodate a pre-positioning tool, such as a pre-positioning screw. Before the fixing plate main body 1 is fixedly connected with the vertebral body by the fixing screws, the pre-positioning screws are used to pass through the pre-positioning opening 15 for temporary positioning.

In the prior art, the main body 1 of the fixing plate is made by bending a metal sheet to a certain degree. However, no matter how it is bent, its upper and lower surfaces are all parallel. As shown in FIG. 3 , which is a cross-sectional view at AA in FIG. 2 , the vertebral body contact surface 2 connected to the vertebral body and the tissue contact surface 3 connected to the tissue are arranged in parallel. That is, in the prior art, the curvature radius R ₁ corresponding to the vertebral body contact surface 2 is equal to the curvature radius R ₂ corresponding to the tissue contact surface 3 . However, in practical applications, due to the small diameter of the cervical vertebral body, if R ₂ is set too small in order to increase the fit, the tissue contact surface 3 will be too "protruding" because R ₁ and R ₂ are equal. The tissue contact surface 3 will be in direct or indirect contact with the muscles of the neck, the esophagus, the trachea and other tissues and organs. Especially for the peristaltic esophagus, the too "protruding" tissue contact surface 3 will rub against the esophagus, causing a foreign body sensation. However, due to the limitations of the processing technology, it is impossible to set the vertebral body contact surface 2 and the tissue contact surface 3 to be non-parallel, so we have to face a dilemma.

This embodiment is made by 3D printing technology, which solves this technical problem. In this embodiment, due to the 3D printing process, the vertebral body contact surface 2 and the tissue contact surface 3 can be set in a non-parallel state. Preferably, the radius of curvature R ₁ is smaller than or equal to the radius of curvature R ₂ . That is, the curvature radius of the vertebral body contact surface 2 is relatively small, so as to fit better with the cervical vertebral body. At the same time, the radius of curvature of the tissue contacting surface 3 is relatively large, which makes the tissue contacting surface 3 more "flat" and reduces the influence of the tissue contacting surface 3 on external tissues.

Example 2

FIG. 4 and FIG. 5 are structural schematic diagrams of the fixing plate main body 1 used in another embodiment of the present application. 5 is a structural diagram of this embodiment observed from the perspective of the contact surface of the vertebral body. In this embodiment, the structure of the main body 1 of the fixing plate includes screw holes 11, weight-reducing openings 12, visible openings 14, connecting holes 131 for shielding parts, pre-positioning openings 15, vertebral body contact surfaces 2, and tissue contact surfaces 3 The non-parallel setting is the same as in Example 1. The difference is that the fixing plate main body 1 includes a solid part 5 and a loose part 4 . The solid part 5 and the loose part 4 form two layers that are attached to each other, and together constitute the entire fixing plate main body 1 . Specifically, the loose part 4 is a layer close to the vertebral body contact surface 2 , and the solid part 5 is a layer close to the tissue contact surface 3 . Preferably, the thickness of the loose part 4 is 0.1-0.3mm, and the thickness of the solid part is 2.0-2.4mm. The loose part 4 has a relatively rough surface, so when the vertebral body contact surface 2 is attached to the vertebral body, a relatively large lateral friction force can be generated. The surface of the solid part 5 is polished so that the tissue contact surface 3 becomes a relatively smooth surface. Therefore, the whole fixing plate main body 1 has a smooth surface and a rough surface. When the external muscles and tissues, especially the esophagus are in the process of peristalsis, they bring less friction to the tissue contact surface 3, and at the same time, the roughness of the vertebral body contact surface 2 makes it more difficult for the fixed plate main body 1 and the vertebral body to produce lateral relative movement. In this way, the stability and safety of the entire anterior cervical fixation system can be improved.

In this embodiment, both the loose part 4 and the solid part 5 are made of titanium alloy metal powder through a 3D printing process. The loose part 4 may be a porous structure, preferably a trabecular bone structure. In a similar embodiment, the loose part 4 can also be configured as a series of periodic protrusions and depressions, so as to increase the friction coefficient of its surface.

The preferred specific embodiments of the present application have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes based on the concept of the present application without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present application on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (10)

1. A cervical spine anterior fixation system based on 3D printing, comprising a fixed plate main body and a fixed screw, the fixed plate main body is fixedly connected with the vertebral body through the fixed screw, it is characterized in that the fixed plate main body includes a vertebral body The contact surface is not parallel to the tissue contact surface, and the vertebral body contact surface is not parallel to the tissue contact surface. 2. The anterior cervical spine fixation system based on 3D printing according to claim 1, wherein the contact surface of the vertebral body and the contact surface of the tissue are both curved surfaces, and the radius of curvature of the contact surface of the vertebral body is less than or equal to The radius of curvature of the tissue-contacting surface. 3. The anterior cervical fixation system based on 3D printing according to claim 2, wherein the main body of the fixation plate comprises a solid part and a loose part, the solid part is fixedly connected to the loose part, and the solid part The part is arranged on a side close to the tissue contact surface, and the loose part is arranged on a side close to the vertebral body contact surface. 4. The anterior cervical spine fixation system based on 3D printing according to claim 3, wherein the thickness of the solid part is 2mm-2.4mm, and the thickness of the loose part is 0.1mm-0.3mm. 5. The anterior cervical spine fixation system based on 3D printing according to claim 4, wherein the loose part is a trabecular bone structure. 6. The anterior cervical spine fixation system based on 3D printing according to claim 5, wherein the main body of the fixing plate includes screw holes, the screw holes are used to accommodate the fixing screws, and the fixing screws pass through the The above-mentioned screw holes are used to realize the fixed connection between the main body of the fixing plate and the vertebral body. 7. The anterior cervical spine fixation system based on 3D printing according to claim 6, characterized in that 8 screw holes are included. 8. The 3D printing-based anterior cervical fixation system according to claim 7, characterized in that, the anterior cervical fixation system further comprises a blocking part, the blocking part is detachably connected to the main body of the fixing plate, The blocking part is used to prevent the fixing screw from passing through or exiting from the screw hole. 9. The 3D printing-based anterior cervical fixation system according to claim 8, wherein the main body of the fixation plate further comprises a shielding part accommodation groove, and the shielding part accommodation groove is used to accommodate the shielding part, so The accommodating groove of the blocking part overlaps with the screw hole. 10. The anterior cervical fixation system based on 3D printing according to claim 9, characterized in that it comprises 4 said shielding part accommodation grooves, each of said shielding part accommodation grooves is connected with 2 said screw holes respectively. Partially overlapping settings.

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