Spine fusion cage

Abstract

The utility model discloses a spine fusion cage, relates to medical instrument technical field, including base body, base body is used for supporting in the intervertebral space, base body includes opposite first side and second side, first side and second side are equipped with a plurality of deformation parts that are distributed side by side in the horizontal direction, each deformation part is vertically supported on the upper side and lower side of base body, and each deformation part can deform along with the height change of the intervertebral space so as to support the intervertebral space. According to the spinal fusion cage, the stability of a postoperative lumbar vertebra structure and the bone healing effect are improved.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a spinal fusion device. Background Technology

[0002] Traditional spinal fusion surgery achieves intervertebral bony fusion by implanting rigid fusion devices (such as PEEK or titanium alloy fusion devices). Although it can stabilize spinal segments in the short term, its static mechanical properties have significant limitations: rigid support leads to excessive load concentration at the fusion device-bone interface, causing stress shielding effect, inhibiting surrounding bone remodeling, and increasing the risk of fusion failure and adjacent segment degeneration; in addition, completely restricting segmental micromotion may weaken the transmission of physiological loads in the spine, affect the biological environment for bone healing, and lead to pseudoarthrosis.

[0003] Existing improved dynamic fusion devices (such as those with gradually changing elastic modulus) attempt to disperse stress through local deformation, but they still face problems such as insufficient mechanical adaptability, mismatch between dynamic range and spinal physiological movement, which accelerates fatigue fracture, or insufficient precision in micro-motion control, making it difficult to balance the contradiction between "stability required for bone healing" and "protection of adjacent segments". Utility Model Content

[0004] The purpose of this invention is to provide a spinal fusion device to solve the problems existing in the prior art and improve the stability of the lumbar spine structure and the bone healing effect after surgery.

[0005] To achieve the above objectives, this utility model provides the following solution:

[0006] This utility model provides a spinal fusion device, including a base for supporting the intervertebral space. The base includes a first side and a second side opposite to each other. The first side and the second side are provided with a plurality of deformable components arranged side by side in a horizontal direction. Each deformable component is vertically supported on the upper and lower sides of the base. Each deformable component can deform with the change of the height of the intervertebral space to provide support.

[0007] Preferably, the substrate includes an upper cover plate, a lower cover plate, a middle support, and two side support members respectively placed on the first side and the second side. The middle support is placed between the upper cover plate and the lower cover plate, and the two side support members are respectively placed on opposite sides of the middle support. Each deformation component is placed inside the corresponding side support member, and both ends of each deformation component are respectively connected to the upper cover plate and the lower cover plate.

[0008] Preferably, the upper cover plate, the lower cover plate, and the side support are all made of titanium alloy, and the intermediate support is made of PEEK material.

[0009] Preferably, an intermediate layer is provided between the edge of the upper cover plate and the upper end of the two side supports, and each of the deformable components passes through the intermediate layer and is connected to the upper cover plate. The intermediate layer is made of PEEK material.

[0010] Preferably, the sides of the upper and lower cover plates that are in contact with the vertebral endplates are provided as porous surfaces.

[0011] Preferably, the interface between the intermediate support and the upper cover plate, lower cover plate and side support member has a reinforcing layer.

[0012] Preferably, the substrate is provided with a bone graft window, an observation window, and a surgical forceps operating port.

[0013] Preferably, the edges of the substrate and each of the deformable components are rounded; and the edges of the substrate are provided with marking points for development positioning.

[0014] Preferably, each of the deformable components is configured as a scissor-type telescopic component, the side support has a sandwich layer, and the scissor-type telescopic component is disposed within the sandwich layer corresponding to the side support; each hinge of the scissor-type telescopic component is provided with a wear-resistant bushing; the scissor-type telescopic component can deform with the change of intervertebral disc height to provide nonlinear support in the vertical direction.

[0015] Preferably, each of the deformable components is configured as an elastic element, and the side support includes a support wall and a plurality of sleeves, the plurality of sleeves being correspondingly arranged with the plurality of deformable components, each sleeve having a side opening and being connected to the support wall to form an accommodating cavity capable of accommodating the corresponding deformable component; the elastic element can deform with changes in intervertebral disc height to provide dynamic support.

[0016] The present invention achieves the following technical advantages over the prior art:

[0017] The spinal fusion device provided by this utility model places the base within the intervertebral space for support and fusion. Multiple deformable components are arranged side-by-side on both the first and second sides of the base. Each deformable component can deform according to changes in the height of the intervertebral space, providing adaptive support. Furthermore, the multiple deformable components distributed in multiple locations provide appropriate height changes as the intervertebral space height changes, achieving height self-adaptation at different parts of the fusion device, reducing the risk of adjacent joint degeneration, and improving postoperative lumbar spine stability and bone healing. Moreover, based on the postoperative biomechanical environment of the lumbar spine, the support performance of corresponding parts can be individually adjusted by regulating the parameters of the corresponding deformable components, further reducing the risk of adjacent joint degeneration and improving postoperative lumbar spine stability and bone healing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the spinal fusion device provided in Embodiment 1;

[0020] Figure 2 An exploded view of the spinal fusion device provided in Embodiment 1;

[0021] Figure 3 This is a schematic diagram of the scissor-type telescopic component provided in Embodiment 1;

[0022] Figure 4 This is a schematic diagram of the application state model of the spinal fusion device provided in Example 1;

[0023] Figure 5 An exploded view of the spinal fusion device provided in Example 2.

[0024] In the diagram: 1-Base; 11-First side; 12-Second side; 13-Upper cover plate; 14-Lower cover plate; 15-Intermediate support; 16-Side support; 161-Interlayer; 162-Support wall; 163-Sleeve; 17-Intermediate layer; 18-Bone graft window; 19-Observation window; 20-Surgical forceps operating port; 2-Deformable component; 21-Scissor-type telescopic component; 22-Elastic component; 3-L4 cortical bone; 4-Surgical endoscope channel; 5-Annulus fibrosus; 6-Titanium rod; 7-Pedicle screw. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] The purpose of this invention is to provide a spinal fusion device to solve the problems existing in the prior art and improve the stability of the lumbar spine structure and the bone healing effect after surgery.

[0027] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] This embodiment provides a spinal fusion device; please refer to [link / reference]. Figure 1 , Figure 2 and Figure 3 The system includes a base 1 for supporting the intervertebral space. The base 1 includes a first side 11 and a second side 12 opposite to each other. Both the first side 11 and the second side 12 are provided with a plurality of deformable components 2 arranged side by side in the horizontal direction. Each deformable component 2 is vertically supported on the upper and lower sides of the base 1. Each deformable component 2 can deform with the change of the height of the intervertebral space to provide support.

[0030] The working principle of the spinal fusion device provided in this embodiment is as follows:

[0031] The base 1 is placed within the intervertebral space for fusion support. Multiple deformable components 2 are arranged side-by-side on the first side 11 and the second side 12 of the base 1. Each deformable component 2 can deform vertically according to changes in the intervertebral space height, enabling adaptive adjustment of vertical stiffness. Furthermore, the multiple deformable components 2 distributed at multiple locations provide suitable height changes when the intervertebral space height changes, achieving height self-adaptation at different parts of the fusion device, reducing the risk of adjacent joint degeneration, and improving postoperative lumbar spine stability and bone healing. Moreover, based on the postoperative biomechanical environment of the lumbar spine, the support performance of corresponding parts can be individually adjusted by regulating the parameters of the corresponding deformable components 2, further reducing the risk of adjacent joint degeneration and improving postoperative lumbar spine stability and bone healing.

[0032] In a preferred embodiment, the base 1 includes an upper cover plate 13, a lower cover plate 14, an intermediate support 15, and two side supports 16 respectively placed on the first side 11 and the second side 12. The intermediate support 15 is placed between the upper cover plate 13 and the lower cover plate 14, and the two side supports 16 are placed on opposite sides of the intermediate support 15. Each deformable component 2 is placed inside the corresponding side support 16, and both ends of each deformable component 2 are connected to the upper cover plate 13 and the lower cover plate 14 respectively. The upper cover plate 13 and the lower cover plate 14 are in contact with the endplate of the intervertebral disc, the intermediate support 15 can provide support, and the side supports 16 can protect the deformable components 2. The height change of the intervertebral disc is acted upon by the upper cover plate 13 and the lower cover plate 14, so that each deformable component 2 can perform adaptive deformation support.

[0033] In this embodiment, a preferred embodiment is that the upper cover plate 13, the lower cover plate 14, and the side support 16 are all made of titanium alloy, while the middle support 15 is made of PEEK. The titanium alloy material used for the upper cover plate 13 and the lower cover plate 14 provides better biocompatibility, which is beneficial for bone reconstruction after implantation. The PEEK matrix ensures sufficient initial stiffness and height of the fusion device while avoiding stress shielding. PEEK material is polyetheretherketone, with an elastic modulus of 3-4 GPa. Using a titanium alloy and PEEK composite material ensures sufficient initial stiffness and height of the fusion device, allowing its initial stiffness to approach that of human cortical bone, promoting bone healing. Simultaneously, while maximizing the good biocompatibility of titanium alloy, it avoids the stress shielding phenomenon that easily occurs with pure titanium fusion devices.

[0034] In the optional scheme of this embodiment, more preferably, an intermediate layer 17 is provided between the edge of the upper cover plate 13 and the upper end of the two side support members 16. Each deformable component 2 passes through the intermediate layer 17 and is connected to the upper cover plate 13. The intermediate layer 17 is made of PEEK material. That is, the edge of the upper cover plate 13 and the two side support members 16 are not directly connected, but are connected through the PEEK intermediate layer 17. By avoiding the direct connection between the titanium alloy upper cover plate 13 and the two side support members 16, the stress shielding phenomenon that is easy to occur in pure titanium fusion is avoided. The intermediate layer 17 can be directly integrated into the intermediate support 15. That is, the intermediate layer 17 is provided with protruding parts on both sides of the upper end of the intermediate support 15, or the intermediate layer 17 can be arranged in a ring and pressed between the upper cover plate 13 and the intermediate support 15.

[0035] In addition, each deformable component 2 passes through the intermediate layer 17 and is connected to the upper cover plate 13. That is, the part of the upper end of the deformable component 2 that extends out of the side support 16 is wrapped with PEEK material to improve the mechanical stability of the overall structure of the fusion device.

[0036] In the optional embodiments of this example, more preferably, the sides of the upper cover plate 13 and the lower cover plate 14 that are in contact with the vertebral endplate are configured as porous surfaces; specifically, the upper cover plate 13 and the lower cover plate 14 cover 96%-98% of the contact area between the fusion device and the endplate, and the surface is treated with micro-arc oxidation to form a porous titanium layer with a pore size of 50-200μm and a porosity of ≥65%, so as to utilize the excellent biocompatibility of titanium alloy to enhance bone ingrowth ability.

[0037] In the optional embodiments of this example, a more preferred embodiment is that the interface between the intermediate support 15 and the upper cover plate 13, the lower cover plate 14 and the side support 16 has a reinforcing layer. Specifically, by forming a titanium-PEEK transition layer, i.e., a reinforcing layer, at the interface, the interfacial shear strength is improved, thereby enhancing the overall stability. Specifically, by using a composite 3D printing technology of selective laser melting (SLM) and fused deposition modeling (FDM), a gradient structure fusion of titanium alloy and PEEK is achieved at the interface. A porous titanium transition layer with gradually changing porosity is generated on the surface of the titanium alloy matrix, and then the PEEK matrix is ​​printed layer by layer to form a reinforced interface with mechanical interlocking and chemical bonding synergy, enhancing the interfacial shear strength. This gradient structure makes the vertical stiffness of the fusion device exhibit a nonlinear gradual change, while the stress concentration coefficient of the titanium-PEEK interface is significantly reduced, suppressing the risk of fretting wear and delamination failure.

[0038] More preferably, the titanium alloy upper cover plate 13, lower cover plate 14, and side support 16 can be integrally formed by 3D printing. The intermediate support 15 and intermediate layer 17 of the PEEK matrix are printed layer by layer with a layer thickness of 0.1 mm and a filling rate of 80%-85%, so that the overall stiffness of the fusion device is reduced to 10-20 GPa close to that of cortical bone to reduce postoperative stress shielding. The thickness of the upper cover plate 13 and lower cover plate 14 is 0.3±0.05 mm to reduce the risk of coating peeling during implantation.

[0039] In the optional embodiments of this example, more preferably, the base 1 is provided with a bone graft window 18, an observation window 19, and a surgical forceps operating port 20. Specifically, the bone graft window 18 vertically penetrates the base 1, that is, the base 1 includes an upper cover plate 13, a lower cover plate 14, an intermediate support 15, and an intermediate layer 17, which are hollowed out to form the bone graft window 18, providing space for bone growth. The observation window 19 is located on the sides of the two side supports 16 and the intermediate support 15, making it convenient for medical staff to observe the internal situation. The surgical forceps operating port 20 is located on the rear side of the side supports 16 and the intermediate support 15 to adapt to the existing minimally invasive endoscopic surgical implant forceps on the market.

[0040] In the optional scheme of this embodiment, it is more preferred that the edges of the base 1 and each deformable component 2 are rounded to avoid possible stress concentration. Specifically, the surfaces of the upper cover plate 13, the lower cover plate 14 and the intermediate support 15 are rounded with a radius of 0.5 mm to eliminate stress concentration at the interface between the fusion device and the final plate. The titanium alloy-PEEK interface inside the fusion device and the structural edges of the deformable component 2 are rounded with a radius of 0.05 mm to reduce the risk of local stress concentration and crack initiation under cyclic loading.

[0041] In the optional scheme of this embodiment, more preferably, the edge of the substrate 1 is provided with marking points for imaging and positioning; specifically, the upper cover plate 13 and the lower cover plate 14 are provided with fluorescent marking points, which are made of europium-doped hydroxyapatite and can be visualized and positioned under intraoperative X-ray fluoroscopy.

[0042] In the optional solutions of this embodiment, the more preferred option is, as follows: Figure 3 As shown, each deformable component 2 is configured as a scissor-type telescopic component 21, and the side support 16 has a sandwich 161. The scissor-type telescopic component 21 is disposed in the sandwich 161 of the corresponding side support 16. The scissor-type telescopic component 21 can deform with the change of intervertebral disc height to provide nonlinear support in the vertical direction. The height of the sandwich 161 is 7.7±0.1mm, and the thickness of the sandwich 161 is 0.1mm, which improves the overall compressive strength and provides a safe and stable working environment for the scissor-type telescopic component 21 in the complex internal environment, while ensuring that the minimum height of the fusion device can meet the intervertebral disc requirements.

[0043] More preferably, the scissor-type telescopic component 21 is composed of multiple X-shaped cross-hinged units connected sequentially, with a single hinge point rotation angle range of ±15°. It can generate a nonlinear stiffness response with changes in intervertebral disc height, providing a progressive support force of 10-80 N / mm in the vertical direction. Utilizing the reaction force generated when the scissor-type telescopic component 21 deforms, it adapts to the patient's physiological condition after fusion, achieving an appropriate height change and preventing potential degeneration of adjacent joints due to rigid fixation. Each hinge point of the scissor-type telescopic component 21 is equipped with a wear-resistant bushing, wherein the wear-resistant bushing is made of silicon nitride ceramic with a friction coefficient ≤0.02 and a wear resistance cycle count ≥1×10⁻⁶. 7 Secondly, to ensure service life; the X-shaped cross hinge unit is composed of two hinged cantilever crosses, and the hinge is achieved by hinge screws.

[0044] Furthermore, the scissor-type telescopic component 21 can adjust parameters such as the span of the single hinge unit, the thickness of the cantilever, and the diameter of the hinge hole according to the patient's physiological state, so as to personalize the vertical stiffness of each part of the fusion device, thereby improving the stability of the lumbar spine structure and the bone healing effect after surgery.

[0045] The spinal fusion device usage state model provided in this embodiment is as follows: Figure 4 As shown, the spinal fusion device is placed in the intervertebral space of the L4 cortical bone model. The vertebral bodies are connected and fixed by titanium rods 6 and pedicle screws 7, and fibrous rings 5 ​​are fitted on the vertebral bodies. The vertebral bodies are provided with surgical endoscope channels 4 to facilitate endoscopic operation during the operation.

[0046] Example 2

[0047] This embodiment provides a spinal fusion device, which differs from the spinal fusion device provided in Embodiment 1 in that: Please refer to... Figure 5 Each deformable component 2 is configured as an elastic element 22. The side support 16 includes a support wall 162 and multiple sleeves 163. The multiple sleeves 163 are correspondingly arranged with the multiple deformable components 2. Each sleeve 163 has a side opening and is connected to the support wall 162 to form a receiving cavity that can accommodate the corresponding deformable component 2. The elastic element 22 can deform with the change of intervertebral disc height to provide dynamic support.

[0048] The working principle of the spinal fusion device provided in this embodiment is as follows:

[0049] The base 1 is placed within the intervertebral space for fusion support. Multiple deformable components 2 are arranged side-by-side on the first side 11 and the second side 12 of the base 1. Each deformable component 2 can deform vertically with changes in the intervertebral space height. These components are distributed in multiple locations. By setting the deformable components 2 as elastic elements 22 with dynamic stiffness response, the elastic elements 22 can generate a dynamic stiffness response with changes in the intervertebral space height. This simulates the dynamic response of the intervertebral disc under different physiological states (flexion, rotation, lateral bending), providing appropriate height changes when the intervertebral space height changes. This allows for height self-adaptation at different parts of the fusion device, reducing the risk of adjacent joint degeneration and improving postoperative lumbar spine stability and bone healing. Furthermore, based on the postoperative biomechanical environment of the lumbar spine, the support performance of corresponding parts can be individually adjusted by regulating the parameters of the corresponding deformable components 2, further reducing the risk of adjacent joint degeneration and improving postoperative lumbar spine stability and bone healing.

[0050] Furthermore, the elastic element 22 is configured as a multi-axially deformable spring, wound with superelastic nickel-titanium alloy (NiTiNOL) wire to achieve a progressive nonlinear stiffness response and multi-axial deformation capability. When the elastic element 22 is subjected to a vertical cyclic load of 10N-800N (frequency 2Hz) in a simulated body fluid environment, the fatigue life is ≥1×10 7 Furthermore, the stiffness attenuation rate is ≤5%, ensuring sufficient service life;

[0051] More preferably, the number and position distribution of springs can be adjusted individually according to the physiological state of different patients. Parameters such as the wire diameter, spring diameter, and effective number of coils of different springs can be adjusted to individually simulate the nonlinear and anisotropic mechanical responses of the human intervertebral disc, and to adjust the vertical stiffness, lateral bending stiffness, and torsional stiffness of various parts of the spinal fusion device. This prevents potential degeneration of adjacent joints caused by rigid fixation, thereby improving the stability of the lumbar spine structure and the bone healing effect after surgery.

[0052] More preferably, the height of the titanium alloy sleeve 163 is the same as that of the titanium alloy support wall 162, which provides a safe and stable working environment for the elastic element 22 by forming a cavity in the complex internal environment.

[0053] Furthermore, the other structures of the spinal fusion device provided in this embodiment are the same as those of the spinal fusion device provided in Embodiment 1, and will not be described in detail here.

[0054] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A spinal fusion device, characterized in that: The system includes a base (1) for supporting the intervertebral space. The base (1) includes a first side (11) and a second side (12) opposite to each other. Both the first side (11) and the second side (12) are provided with a plurality of deformable components (2) arranged side by side in the horizontal direction. Each deformable component (2) is vertically supported on the upper and lower sides of the base (1). Each deformable component (2) can deform with the change of the height of the intervertebral space to provide support.

2. The spinal fusion device according to claim 1, characterized in that: The base (1) includes an upper cover plate (13), a lower cover plate (14), a middle support (15), and two side support members (16) respectively placed on the first side (11) and the second side (12). The middle support (15) is placed between the upper cover plate (13) and the lower cover plate (14), and the two side support members (16) are respectively placed on opposite sides of the middle support (15). Each deformation component (2) is placed inside the corresponding side support member (16), and the two ends of each deformation component (2) are respectively connected to the upper cover plate (13) and the lower cover plate (14).

3. The spinal fusion device according to claim 2, characterized in that: The upper cover plate (13), the lower cover plate (14) and the side support (16) are all made of titanium alloy, and the middle support (15) is made of PEEK.

4. The spinal fusion device according to claim 3, characterized in that: An intermediate layer (17) is provided between the edge of the upper cover plate (13) and the upper ends of the two side support members (16). Each of the deformation components (2) passes through the intermediate layer (17) and is connected to the upper cover plate (13). The intermediate layer (17) is made of PEEK material.

5. The spinal fusion device according to claim 2, characterized in that: The upper cover plate (13) and the lower cover plate (14) are configured with porous surfaces on the sides that are in contact with the vertebral endplate.

6. The spinal fusion device according to claim 2, characterized in that: The intermediate support (15) has a reinforcing layer at the interface where it fits with the upper cover plate (13), the lower cover plate (14) and the side support member (16).

7. The spinal fusion device according to claim 2, characterized in that: The substrate (1) is provided with a bone graft window (18), an observation window (19) and a surgical forceps operating port (20).

8. The spinal fusion device according to claim 2, characterized in that: The edges of the substrate (1) and each of the deformable components (2) are rounded; and the edges of the substrate (1) are marked with markers for development positioning.

9. The spinal fusion device according to any one of claims 2-8, characterized in that: Each of the deformable components (2) is configured as a scissor-type telescopic component (21), the side support (16) has a sandwich (161), and the scissor-type telescopic component (21) is disposed in the sandwich (161) corresponding to the side support (16); each hinge of the scissor-type telescopic component (21) is provided with a wear-resistant bushing; the scissor-type telescopic component (21) can deform with the change of intervertebral disc height to provide nonlinear support in the vertical direction.

10. The spinal fusion device according to any one of claims 2-8, characterized in that: Each of the deformable components (2) is configured as an elastic element (22). The side support (16) includes a support wall (162) and a plurality of sleeves (163). The plurality of sleeves (163) are correspondingly arranged with the plurality of deformable components (2). Each sleeve (163) has a side opening and is connected to the support wall (162) to form a receiving cavity that can accommodate the corresponding deformable component (2). The elastic element (22) can deform with the change of intervertebral disc height to provide dynamic support.

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