A posterior approach intervertebral fusion cage

Abstract

The utility model discloses an intervertebral fusion cage of posterior approach for solving the problem that breakage can appear when rotating and shifting in minimally invasive surgery, and the outer frame and the porous structure are combined into the body of the fusion cage, the outer frame is a strip frame located at the edge of the body of the intervertebral fusion cage and connected with each other, and the whole presents a streamline type, and the porous structure comprises an outer grid and an inner grid, wherein the outer grid is connected with the outer frame. The combination of the different porous structure design and the outer frame realizes a more round cross-sectional shape, reduces the hard friction with the endplate during rotation, and the reinforced porous structure can effectively disperse stress and reduce breakage. The problem that the porous structure is easily damaged when rotating the fusion cage in minimally invasive surgery is solved, the torsional force received during rotation is resisted through the combination of the outer frame and the porous structure, and the flexibility of use is improved.

Description

Technical Field

[0001] This utility model belongs to the field of intervertebral fusion technology, specifically relating to a posterior approach intervertebral fusion device. Background Technology

[0002] The incidence of lumbar degenerative diseases is increasing year by year, and their clinical symptoms are mostly caused by nerve root foramen stenosis. The intervertebral height significantly affects the size of the nerve root foramen. Therefore, current techniques typically use implantation to restore the original space, and different surgical procedures have been developed. Among them, the single intervertebral foramen approach can reduce tissue damage, preserve more facet joints, reduce damage to posterior structures, and enhance postoperative lumbar spine biomechanical stability, making it a commonly used procedure. Although this procedure has these advantages, it is quite challenging in practice. Due to the small minimally invasive channel, continuous adjustments are often required after implantation to find the optimal placement. Because it is a minimally invasive surgery, the distance between the implant and the superior and inferior endplates is small after placement. Adjustments made by rotation are inevitably limited by the endplates. More importantly, for implants with porous structures, the structural design does not consider the additional load generated by rotation. Therefore, existing porous implants are prone to wire breakage during rotation, causing defects or even failure of the porous structure, greatly affecting the safety of use. Utility Model Content

[0003] This utility model discloses a posterior approach interbody fusion device to solve the problem that rotating the fusion device during minimally invasive surgery can easily damage the porous structure. The combination of the outer frame and the porous structure resists the torsional force during rotation and improves the flexibility of use.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] A posterior approach interbody fusion device includes: an outer frame and a porous structure. The outer frame is a frame of strips located on the edges of the interbody fusion device body and connected to each other. The outer frame forms the outline of the body. The porous structure includes an outer mesh and an inner mesh frame. The outer mesh is connected to the outer surface of the outer frame, while the inner mesh frame is located inside the structure enclosed by the outer frame.

[0006] Furthermore, an arc-shaped metal plate that smoothly transitions with the strips is provided between the strips located at the implantation end in the outer frame, thereby forming a smooth and streamlined implantation end.

[0007] Furthermore, the outer surface of the outer mesh is also a curved arc surface, and the connection between the outer mesh and the outer frame is smooth, forming a curved surface together with the outer frame.

[0008] Furthermore, the outer mesh is a convex arc surface.

[0009] Furthermore, the outer grid is provided with a bone graft window, and the inner grid is also reserved with a channel for bone grafting. This channel is connected to the bone graft window of the outer grid, and the two together form a bone graft space that can accommodate the filler.

[0010] Furthermore, there is more than one bone graft space, and they are interconnected.

[0011] Furthermore, the internal network structure is a porous structure with micro-nano topology.

[0012] Its beneficial effects are as follows: the rounded cross-sectional shape of the outer surface formed by the combination of the porous structure and the outer frame reduces the resistance encountered during rotation and adjustment. Moreover, the combination with the porous structure also optimizes the external force, concentrating the resistance during rotation on the outer mesh, which bears the force, while the inner mesh is less prone to fracture failure due to the lower force. On the other hand, the irregular internal grid structure formed by the micro-nano topology, compared with the regular structures commonly used in existing technologies, is similar to a trabecular bone structure and has good strength in all directions, improving the strength of the porous structure and preventing damage to the porous structure during rotation. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 The schematic diagram shows the structure of this utility model;

[0015] Figure 2 The schematic diagram shows the structure of this utility model from a side view angle;

[0016] Figure 3 The schematic diagram shows a cross-sectional view of the present invention.

[0017] In the diagram: 1-outer frame, 2-perforated structure, 21-outer mesh, 22-inner mesh frame, 3-clamping position. Detailed Implementation

[0018] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing this technical solution and do not indicate that the device or component referred to must have a specific orientation; therefore, they should not be construed as limitations on this utility model.

[0019] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary elements. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] In the following description, specific details such as particular system structures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the present invention; however, it will be apparent to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail. Example

[0021] like Figures 2-3 The image shows a posterior approach interbody fusion device used in minimally invasive interbody fusion surgery. It addresses the problem of potential damage to the porous structure during rotation and displacement in minimally invasive surgery. In this embodiment, a more rounded cross-sectional shape is achieved through the combination of different porous structure designs 2 and outer frame 1. This reduces hard friction with the endplate during rotation, while the reinforced porous structure 2 effectively disperses stress and reduces the occurrence of damage.

[0022] Specifically: The outer frame 1 of the fusion device and the porous structure 2 are combined to form the body of the fusion device. One end of the body of the intervertebral fusion device is the clamping end, which has an instrument connection groove to facilitate clamping by the clamping device. The other end is the implantation end, which is tapered towards the axis to form a streamlined shape, which facilitates implantation through a minimally invasive channel. Bone graft windows are provided on both sides of the front and back of the body of the intervertebral fusion device, which is beneficial for later integration with autologous bone tissue.

[0023] The outer frame 1 is located on the edge of the interbody fusion device and is connected to each other to form a whole. The outer frame 1 forms the outline of the body. The two ends of the outer frame are the implantation end and the clamping end, respectively. A clamping position 3 is provided on one side of the clamping end to facilitate clamping and fixation.

[0024] Preferably, a smoothly transitioning curved metal plate is also provided between the strips at the implantation end, such as... Figure 2 As shown, it not only conceals the porous structure 2 inside the implant end, but also forms a smooth and streamlined implant end, which facilitates the implantation of the fusion device into the affected area through a minimally invasive channel.

[0025] The porous structure 2 is set in the outer frame 1 and is a mesh structure made of interwoven metal wires. The porous structure 2 includes an outer mesh 21 and an inner mesh frame 22. The outer mesh 21 is smoothly connected to the outer frame. The wire diameter of the outer mesh 21 is larger than that of the inner mesh frame 22. The outer mesh 21 is a planar mesh structure. After being connected to the outer frame 1, the planar outer mesh 21 can effectively distribute the force and ensure the compressive strength.

[0026] Specifically, the outer mesh 21 is also a curved surface; preferably, the outer mesh 21 is a convex curved surface, and the transition between the outer mesh 21 and the outer frame 1 is smooth, such as... Figures 2-3 As shown, the product cross-section formed by the outer grid 21 and the outer frame 1 has an arc shape on each end face, and the transition between adjacent end faces is smooth. In contrast, the cross-section of the fusion device in the prior art is mostly a right-angle transition. In comparison, the arc transition structure of this application can rotate more smoothly in scenarios where rotation adjustment is required.

[0027] The internal grid 22 is a three-dimensional network structure that fills the main frame and supports the outer frame 1 from the inside. Its structure is similar to the natural trabecular bone structure. After molding, its elastic modulus is closer to that of bone tissue, and it greatly reduces product quality compared to a solid structure.

[0028] Furthermore, the outer mesh 21 is provided with bone graft windows, and the inner mesh frame 22 is also reserved with channels for bone grafting. These channels are connected to the bone graft windows of the outer mesh 21, and the two together form a bone graft space for accommodating autologous bone tissue and other fillers. Preferably, there is more than one bone graft space, with bone graft windows on all four end faces, and two corresponding bone graft spaces, which are interconnected.

[0029] On the other hand, the integral molding of the porous structure 2 and the outer frame 1 improves the overall integrity, and the torque received during rotation can be better distributed, thereby increasing the resistance during rotation.

[0030] In a preferred embodiment, the internal mesh frame 22 is an irregular micro-nano topology structure, which gives the internal mesh frame 22 good compressive strength in all directions, and it is less likely to break when subjected to forces from different directions, especially during rotational adjustment.

[0031] In this embodiment, the topology is constructed using the following method: loads are set according to multiple activity conditions of the vertebra, and topology optimization design is performed in the form of weight in flexion, extension, left and right lateral bending and left and right rotation conditions.

[0032] Using the sum of strain energies under various working conditions as the objective function, the multi-objective topology optimization formula is established as follows:

[0033]

[0034] in: To optimize regional compliance, These are the weighting factors for each load.

[0035] With volume fraction as the constraint, the volume constraint formula is:

[0036]

[0037] in: To optimize the final volume of the region, For the set volume fraction, This represents the original volume of the initial region.

[0038] The product is imported into the topology optimization module of the modeling software for calculation to obtain the optimization results. The topology optimization results are then verified and confirmed to obtain the porous structure and product after topology optimization.

[0039] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A posterior approach interbody fusion device, characterized in that: include: The outer frame and porous structure are connected strips located on the edges of the intervertebral fusion device body and forming the outline of the body. The porous structure includes an outer mesh and an inner mesh frame, wherein the outer mesh is connected to the outer surface of the outer frame, and the inner mesh frame is located inside the structure enclosed by the outer frame.

2. The posterior approach interbody fusion device according to claim 1, characterized in that: The outer frame is spindle-shaped, with the implantation end and the clamping end at its two ends along its length, respectively.

3. The posterior approach interbody fusion device according to claim 2, characterized in that: Between the frames of the implanted end, there is also an arc-shaped metal plate that smoothly transitions with the frames, forming a smooth and streamlined end.

4. The posterior approach interbody fusion device according to claim 1, characterized in that: The outer surface of the outer mesh is also a curved surface with curvature. The connection between the outer mesh and the outer frame is smooth, and they combine to form a curved surface.

5. The posterior approach interbody fusion device according to claim 4, characterized in that: The outer grid is a convex arc surface.

6. The posterior approach interbody fusion device according to claim 1, characterized in that: The outer grid is provided with a bone graft window, and the inner grid is also reserved with a channel for bone grafting. This channel is connected to the bone graft window of the outer grid, and the two together form a bone graft space that can accommodate the filler.

7. The posterior approach interbody fusion device according to claim 1, characterized in that: The internal network structure is a porous structure with micro-nano topology.

Images