Split fusion device and method of manufacturing same

Abstract

This invention provides a split-type fusion device and its manufacturing method. The split-type fusion device includes two independent fusion bodies configured to abut each other when implanted in the body. Each fusion body includes a conductive layer disposed on the side facing the other fusion body, and the fusion body is filled with a piezoelectric elastic material. The conductive layer is electrically connected to the elastic material. This split-type fusion device, by setting two independent, abuttable fusion bodies filled with piezoelectric elastic material and a conductive layer on the abutment surface of the fusion bodies, allows the microcurrent generated by the piezoelectric elastic material to be transmitted through the conductive layer, accelerating bone cell proliferation and differentiation and improving bone fusion efficiency. Simultaneously, the conductive layer guides bone cells to grow directionally at the abutment surface, promoting the gradual separation of the two fusion bodies and achieving adaptive intervertebral height adjustment in vivo. This allows height adjustment and bone fusion to be completed synchronously, solving the problem of the difficulty in simultaneously achieving both.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a split-type fusion device and its manufacturing method. Background Technology

[0002] Interbody fusion is a core surgical procedure for the clinical treatment of spinal diseases such as degenerative spinal disease, vertebral instability, and herniated discs. As the key implant in this procedure, the interbody fusion device's biomechanical fit, bone fusion efficiency, biocompatibility, and long-term implantation stability directly determine the clinical outcome and patient prognosis.

[0003] Existing expandable intervertebral fusion devices mostly rely on built-in mechanical structures to achieve intervertebral height adjustment. They require external instruments to forcibly open the intervertebral space during surgery. This not only fails to accurately adapt to the different vertebral anatomy and individual differences of different patients, but also easily causes complications such as nerve root traction injury, stress fracture of vertebral endplate, and severe postoperative pain due to one-time opening. At the same time, it is difficult to achieve a synergistic improvement in intervertebral height adjustment and bone fusion efficiency, and it is impossible to achieve targeted guidance of bone growth. The stability and fusion effect of long-term implantation are difficult to guarantee.

[0004] In view of this, it is necessary to improve the existing fusion device to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a split-type fusion device to solve the problem that existing fusion devices are unable to simultaneously improve the efficiency of intervertebral height adjustment and bone fusion.

[0006] To achieve the above objectives, the present invention provides a split-type fusion device, which includes two independent fusion bodies configured to abut each other when implanted in the body. Each fusion body includes a conductive layer disposed on the side facing the other fusion body, and the fusion body is filled with a piezoelectric elastic material. The conductive layer is electrically connected to the piezoelectric elastic material.

[0007] As a further improvement of the present invention, the conductive layer is one or more composite structures selected from conductive thin film, conductive metal sheet, and conductive fabric.

[0008] As a further improvement of the present invention, the piezoelectric elastic material is one of polyvinylidene fluoride and its copolymers, medical polyurethane-based piezoelectric elastomers, biodegradable polyester-based piezoelectric elastomers, polyimide piezoelectric elastomers, and piezoelectric hydrogels.

[0009] As a further improvement of the present invention, the fusion body includes a first implant and a second implant, the conductive layer is disposed on the side of the second implant away from the first implant, both the first implant and the second implant are porous structures, and the piezoelectric elastic material is disposed in the second implant.

[0010] As a further improvement of the present invention, the average pore size of the first implant is smaller than that of the second implant.

[0011] As a further improvement of the present invention, the first implant and the second implant are made by printing metal materials.

[0012] As a further improvement of the present invention, the two fusion bodies are a first fusion body and a second fusion body, the first fusion body is provided with at least two guide rods protruding toward the second fusion body, and the second fusion body is provided with at least two guide grooves for inserting and cooperating with the guide rods.

[0013] As a further improvement of the present invention, the guide rod is made of a conductive material, and the guide rod is electrically connected to the piezoelectric elastic material and the conductive layer in the fused body.

[0014] As a further improvement of the present invention, a groove is formed on the surface of the guide rod that contacts the piezoelectric elastic material.

[0015] As a further improvement of the present invention, the surface of the guide rod is formed with a hydrophobic structure.

[0016] As a further improvement of the invention, at least one of the fused bodies is recessed on one side toward the other fused body to form a receiving groove for receiving bone fragments.

[0017] As a further improvement of the present invention, the mating surfaces of the two fused bodies are configured with bending matching.

[0018] The present invention also provides a method for manufacturing a split-type fusion unit, for manufacturing a split-type fusion unit as described above, the method for manufacturing the split-type fusion unit comprising the following steps:

[0019] S1: Fabricate the first implant and the second implant of the first fusion body and the second fusion body respectively, fabricate a guide rod, and insert the guide rod into the first fusion body;

[0020] S2: Immerse the second implant of the first fusion body and the second fusion body into the piezoelectric elastic material solution and wait for the piezoelectric elastic material to solidify.

[0021] S3: Remove the first fusion body and the second fusion body, and remove excess piezoelectric elastic material from the surfaces of the first fusion body and the second fusion body;

[0022] S4: Coat one side of the conductive layer with a piezoelectric elastic material and bond it to the side of the second implant away from the first implant.

[0023] As a further improvement of the present invention, there is a step S11 between step S1 and step S2: providing a first tooling and a second tooling, the first tooling having a clearance groove for inserting a guide rod, and the second tooling having a sealing rod, assembling the second implant of the first fusion body with the first tooling, inserting the guide rod into the clearance groove, assembling the second implant of the second fusion body with the second tooling, and inserting the sealing rod into the guide groove; in step S3, after removing the first fusion body and the second fusion body, removing the first tooling and the second tooling, and then processing the excess piezoelectric elastic material on the surface of the first fusion body and the second fusion body.

[0024] The beneficial effects of this invention are as follows: The split fusion device of this invention sets up two independent fusion bodies that can abut and are filled with piezoelectric elastic material, as well as a conductive layer on the mating surface of the fusion bodies. The microcurrent generated by the piezoelectric elastic material is transmitted through the conductive layer, which can accelerate the proliferation and differentiation of bone cells and improve the bone fusion efficiency. At the same time, the conductive layer guides the bone cells to grow in a directional manner at the mating surface, promoting the gradual separation of the two fusion bodies, realizing the adaptive intervertebral height adjustment in vivo, and allowing the height adjustment and the bone fusion process to be completed synchronously, solving the pain point that it is difficult to achieve both at the same time. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a three-dimensional structural diagram of the split-type fusion device of the present invention;

[0027] Figure 2 This is an exploded structural diagram of the split-type fusion device of the present invention;

[0028] Figure 3 This is an exploded structural diagram of the split-type fusion device of the present invention from another angle;

[0029] Figure 4 This is a schematic cross-sectional view of the split-type fusion device of the present invention after it has been implanted into the human body.

[0030] Figure 5 This is a cross-sectional structural diagram of the first fusion body and the first tooling assembly of the split fusion device of the present invention.

[0031] Figure 6 This is a cross-sectional structural diagram of the first fusion body of the split-type fusion device of the present invention;

[0032] Figure 7 This is a cross-sectional structural diagram of the first tooling;

[0033] Figure 8This is a cross-sectional structural diagram of the second fusion body of the split-type fusion device of the present invention;

[0034] Figure 9 This is a cross-sectional structural diagram of the second tooling;

[0035] Figure 10 This is a cross-sectional structural diagram of the split-type fusion device of the present invention;

[0036] Figure 11 This is a flowchart of the manufacturing method of the split-type fusion device of the present invention.

[0037] Reference numerals: 100, Split-type fusion device; 1, Fusion body; 11, First fusion body; 111, Guide rod; 112, Receiving groove; 12, Second fusion body; 121, Guide groove; 13, First implant; 14, Second implant; 15, Conductive layer; 151, Cell climbing area; 16, Piezoelectric elastic material; 200, First tooling; 201, Displacement groove; 300, Second tooling; 301, Sealing rod. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0041] like Figures 1 to 10 As shown, the split fusion device 100 of the present invention includes two independent fusion bodies 1, which are configured to abut each other when implanted in the body. Each fusion body 1 includes a conductive layer 15 disposed on the side facing the other fusion body 1, and the fusion body 1 is filled with a piezoelectric elastic material 16. The conductive layer 15 is electrically connected to the piezoelectric elastic material 16.

[0042] In this embodiment, both fusion bodies 1 are provided with a conductive layer 15. The conductive layer 15 is located on the contact surface of the two fusion bodies 1, which can attract bone cells to preferentially grow in this area. At the same time, the piezoelectric elastic material 16 of the second implant 14 can generate electrical signals to the conductive layer 15, further activating bone cell proliferation and differentiation, and guiding bone cells to grow directionally into the contact area of ​​the fusion body 1. The directional growth of bone cells in the conductive layer 15 area will promote the gradual separation of the two fusion bodies 1, enabling the fusion device to self-open in vivo without the need for external instruments. It can adaptively adjust the intervertebral height, match the physiological remodeling rhythm of the vertebral body and surrounding soft tissues, and avoid the risk of damage such as nerve root traction and endplate fracture caused by traditional one-time opening.

[0043] After implantation into the human body, a cell climbing region 151 is formed between the two conductive layers 15, and bone cells grow in the cell climbing region 151.

[0044] The conductive layer 15 is one or more composite structures selected from conductive thin film, conductive metal sheet, and conductive fabric.

[0045] The piezoelectric elastomer 16 is one of the following: polyvinylidene fluoride and its copolymers, medical polyurethane-based piezoelectric elastomers, biodegradable polyester-based piezoelectric elastomers, polyimide piezoelectric elastomers, and piezoelectric hydrogels. In this embodiment, a piezoelectric hydrogel is selected. All of the above materials are piezoelectric materials and possess a certain degree of elasticity. They are liquid at room temperature and can solidify into a solid state after the addition of material AB.

[0046] The fusion body 1 includes a first implant 13 and a second implant 14. The conductive layer 15 is disposed on the side of the second implant 14 away from the first implant 13. Both the first implant 13 and the second implant 14 are porous structures. The piezoelectric elastic material 16 is disposed in the second implant.

[0047] The pores of the second implant 14 are filled with piezoelectric elastic material 16 to form a physical barrier, preventing osteocytes from colonizing in the area and ensuring that bone growth is targeted and concentrated in the area where the fusion body 1 contacts the lamina, thereby achieving rapid bony connection between the split fusion device 100 and the upper and lower lamina.

[0048] It should be noted that the first implant 13 and the second implant 14 can be integrally formed, or they can be formed separately and then fixedly connected.

[0049] The first implant 13 and the second implant 14 provide basic structural strength. The elastic properties of the piezoelectric elastic material 16 can buffer the instantaneous stress of vertebral movement, significantly improving the fatigue resistance of the split fusion device 100 and extending its service life in vivo. At the same time, the piezoelectric elastic material 16 replaces the traditional dense metal structure, and the amount of metal material used is reduced due to the porous design, achieving an overall weight reduction of the device and solving the pain point of traditional metal implants that are difficult to balance strength and lightweight. In addition, the elastic modulus of the piezoelectric elastic material 16 is very close to that of the intervertebral nucleus pulposus tissue, which can simulate the physiological elastic function of the nucleus pulposus, adapt to the vertebral body's biomechanical microenvironment, and avoid the problem of biomechanical mismatch between the implant and the vertebral body.

[0050] The piezoelectric elastic material 16 replaces the inorganic non-metallic hard and brittle piezoelectric ceramic of traditional piezoelectric fusion devices, significantly improving its affinity with human vertebral bones and soft tissues. This reduces the foreign body recognition reaction of the immune system after implantation, avoids the formation of a dense fibrous connective tissue capsule, prevents the split fusion device 100 from being isolated from the surrounding bone tissue, and ensures the adhesion, proliferation, and ingrowth of bone cells. At the same time, compared with traditional pure titanium alloy or ceramic fusion devices, the composite structure has a material combination that is closer to the physiological structure of the intervertebral space, greatly reducing the risk of foreign body reaction and chronic inflammation after implantation, and improving the biosafety of implantation.

[0051] The piezoelectric elastic material 16 within the second implant 14 can generate microcurrent stimulation. This electrical signal can be transmitted to the conductive layer 15 and act on the surrounding vertebral tissue, effectively activating pathways related to osteocyte proliferation and differentiation, accelerating bone tissue ingrowth and fusion. Compared to traditional fusion devices without electrical stimulation, it significantly improves the efficiency and clinical success rate of intervertebral fusion. At the same time, it leaves room for subsequent technological iterations, allowing the piezoelectric elastic material 16 to be replaced with a biodegradable type, achieving uniform growth of bone tissue within the overall structure of the fusion device, and further improving the long-term bone integration effect.

[0052] The average pore size of the first implant 13 is smaller than that of the second implant 14. Specifically, the first implant 13 has densely arranged micropores, while the second implant 14 has sparsely arranged macropores. Here, "dense," "sparse," "micropores," and "macropores" are all relative terms. This differentiated pore design—dense micropores in the first implant 13 and sparse macropores in the second implant 14—allows the first implant 13 to form a dense structural support surface, ensuring structural strength at the contact point with the vertebral lamina and providing a fine channel for bone ingrowth. Simultaneously, the sparse macropores in the second implant 14 can fully accommodate the piezoelectric elastic material 16, achieving stable filling of the piezoelectric elastic material 16 and effective conduction of electrical signals. The macropore structure also provides space for the piezoelectric elastic material 16 to exert its elastic buffering effect. Furthermore, the gradient design of the micropores and macropores can guide bone cells to preferentially grow on the side of the first implant 13, thus achieving self-opening and staged bone fusion of the fusion device, balancing structural mechanical properties and targeted bone integration.

[0053] The first implant 13 and the second implant 14 are fabricated using metal materials. In this embodiment, the first implant 13 and the second implant 14 are fabricated using titanium alloy materials. Titanium alloy has excellent biocompatibility, mechanical strength and corrosion resistance, and is suitable for the physiological environment of human implantation, reducing the risk of adverse reactions and material loss after implantation. At the same time, the 3D printing process can accurately realize the differentiated pore arrangement, size and structural design requirements of the two, ensuring the forming accuracy of the gradient pore layout, and accurately implementing the structural features of dense micropores and sparse macropores. It takes into account the structural stability of the fusion device and the functional requirements of bone ingrowth and piezoelectric elastic material 16 filling. Moreover, the printing molding can realize integrated preparation, improving the overall structure of the product and the reliability of the connection between various components.

[0054] The two fusion bodies 1 are a first fusion body 11 and a second fusion body 12. The first fusion body 11 has at least two guide rods 111 protruding toward the second fusion body 12, and the second fusion body 12 has at least two guide grooves 121 for inserting and cooperating with the guide rods 111.

[0055] The first fusion body 11 is provided with a protruding guide rod 111, and the second fusion body 12 is provided with a matching guide groove 121 to form a plug-in fit. Both the guide rod 111 and the guide groove 121 are provided with at least two, which not only provides precise directional guidance for the self-opening movement of the two fusion bodies 1, ensuring that the fusion bodies 1 open smoothly and horizontally along the preset direction, effectively preventing problems such as tilting and deviation during the opening process, and ensuring the uniformity and stability of the intervertebral height adjustment, but also enhances the structural fit of the two fusion bodies 1 through the plug-in structure.

[0056] In this embodiment, the number of guide rods 111 is set to at least three and arranged in a planar pattern. Compared with the linear support of a smaller number of guide rods 111, a multi-directional planar positioning and support system can be formed, which can achieve more comprehensive and precise directional constraints on the opening movement of the fusion body 1. It can effectively limit the offset and tilt of the fusion body 1 from multiple dimensions, ensuring that it maintains a horizontal and stable movement state throughout the self-opening process. This allows for uniform and symmetrical gradual adjustment of the intervertebral height, avoiding problems such as uneven vertebral force and fusion device displacement caused by opening imbalance. In this embodiment, the number of guide rods 111 and guide grooves 121 is four each.

[0057] The guide rod 111 is made of conductive material and is electrically connected to the piezoelectric elastic material 16 and the conductive layer 15 within the fusion body 1. The guide rod 111, made of conductive material and electrically connected to the piezoelectric elastic material 16 and the conductive layer 15, serves as a reliable pathway for electrical signal transmission between the piezoelectric elastic material 16 and the conductive layer 15, stably and efficiently conducting the microcurrent generated by the piezoelectric elastic material 16 to the conductive layer 15 at the contact surface of the fusion body 1. This provides stable electrical stimulation for the aggregation and activation of bone cells in the conductive layer 15, aiding in the directional growth of bone cells and the self-opening of the fusion device. Furthermore, it eliminates the need for an additional independent wire structure, simplifying the overall structural design of the split fusion device 100. Simultaneously, the conductive guide rod 111 still fulfills its original supporting and guiding functions of directional opening and anti-tilting, achieving a functional integration of structural support and electrical signal transmission, thus balancing the structural simplicity and functional practicality of the fusion device.

[0058] When the guide rod 111 is inserted into the conductive groove, the guide rod 111 is simultaneously connected to the conductive parts of the first fusion body 11 and the second fusion body 12, as well as the piezoelectric elastic material 16.

[0059] The surface of the guide rod 111 in contact with the piezoelectric elastic material 16 has grooves. The grooves on the surface of the guide rod 111 in contact with the piezoelectric elastic material 16 create a rough structure, which significantly increases the contact area and mechanical interlocking force between the guide rod 111 and the piezoelectric elastic material 16. This allows the piezoelectric elastic material 16 to penetrate more fully into the grooves and bind tightly to the guide rod 111, effectively preventing displacement or detachment of the piezoelectric elastic material 16 during movement or expansion within the body. This ensures the continuity and stability of electrical signal transmission between the piezoelectric elastic material 16, the conductive guide rod 111, and the conductive layer 15, while also improving the overall integrity of the composite structure, providing a reliable functional basis for the directed growth of bone cells and the self-expansion of the fusion device.

[0060] The surface in contact with the piezoelectric elastic material 16 here refers to the surface that is fused with the piezoelectric elastic material 16 of the first fusion body 11 and the piezoelectric elastic material 16 of the second fusion body 12.

[0061] The guide rod 111 has a hydrophobic structure on its surface. The surface of the guide rod 111 is laser-treated to form a hydrophobic microtexture, which can effectively prevent osteocytes from adhering, colonizing and growing on the surface of the guide rod 111 after implantation. This prevents the bone tissue from prematurely fusing the guide rod 111 and the fusion body 1 together, ensuring that the two fusion bodies 1 can still smoothly complete the self-opening action along the guide structure during the bone healing process, maintaining the effectiveness and continuity of intervertebral height adjustment. At the same time, the hydrophobic structure does not affect the electrical signal conduction function of the guide rod 111, which not only ensures the stability of the electrical stimulation pathway between the piezoelectric elastic material 16 and the conductive layer 15, but also prevents the failure of the opening function due to premature bone fusion, providing a reliable structural guarantee for staged bone healing and intervertebral fusion.

[0062] At least one of the fusion bodies 1 has a recessed side facing the other fusion body 1 to form a receiving groove 112 for accommodating bone fragments. The receiving groove 112 formed by the recess of at least one fusion body 1 facing the other fusion body 1 can effectively collect and retain autologous bone fragments during implantation, providing a natural osteoinductive microenvironment for osteoblast proliferation and differentiation, and accelerating the bone fusion process in the contact area of ​​the fusion body 1. At the same time, the receiving groove 112 can physically limit the bone fragments, preventing bone fragments from shifting or being lost in the body, ensuring the full utilization of bone repair materials. Combined with the guiding effect of the conductive layer 15 and electrical stimulation, it further improves the efficiency and long-term stability of intervertebral fusion, providing a reliable histological basis for bone integration after the split fusion device 100 is opened.

[0063] In this embodiment, the receiving slot 112 is disposed on the first fusion body 11.

[0064] The mating surfaces of the two fusion bodies 1 are configured with a curved matching feature. This curved matching feature utilizes the geometric self-locking properties of the curved surface structure to effectively limit horizontal displacement or lateral misalignment of the fusion bodies 1 during the unfolding process. This ensures precise alignment and smooth unfolding of the two fusion bodies 1 along a preset vertical direction, eliminating the risk of tilting or shifting. Simultaneously, the curved self-locking structure eliminates the need for additional locking components, maintaining a stable relative position after unfolding. This significantly improves the overall structural rigidity and long-term stability of the fusion device, ensuring effective maintenance of intervertebral height and preventing clinical problems such as nerve root compression or fusion failure caused by horizontal misalignment.

[0065] like Figures 5 to 11 As shown, the manufacturing method of the split-type fusion unit 100 includes the following steps:

[0066] S1: First implants 13 and 14 of the first fusion body 11 and the second fusion body 12 are fabricated respectively, and guide rods 111 are fabricated and installed in the first fusion body 11. In this embodiment, 3D printing technology is used to prepare the first fusion body 11 and the second fusion body 12 respectively using titanium alloy as raw material. The first implant 13 is set on the side away from the docking surface and adopts a dense microporous structure to provide stable mechanical support and bone ingrowth channel. The second implant 14 is set on the side close to the docking surface and adopts a sparse macroporous structure to provide sufficient filling space for the piezoelectric elastic material 16. At the same time, a channel for guide rod 111 is reserved on the first fusion body 11. The guide rod 111 made of conductive material is installed in the channel. The surface of the guide rod 111 in contact with the piezoelectric elastic material 16 is machined to form grooves to enhance the interlocking. The remaining surface is laser-treated to form a hydrophobic microtexture to prevent subsequent bone cell adhesion and growth.

[0067] S11: Provide a first tooling 200 and a second tooling 300. The first tooling 200 is provided with a relief groove 201 for the guide rod 111 to be inserted. The second tooling 300 is provided with a sealing rod 301. Assemble the second implant 14 of the first fusion body 11 with the first tooling 200 and insert the guide rod 111 into the relief groove 201. Assemble the second implant 14 of the second fusion body 12 with the second tooling 300 and insert the sealing rod 301 into the guide groove 121.

[0068] A first tooling 200 and a second tooling 300 are prepared to precisely fit the outer contours and functional areas of the first fusion body 11 and the second fusion body 12. The tooling is made of medical-grade corrosion-resistant and high-dimensional stability rigid material and can be formed with high precision by 3D printing or machining. The first tooling 200 has relief grooves 201 that correspond one-to-one with the number, arrangement, and outer diameter of the guide rods 111 of the first fusion body 11. The depth of the relief grooves 201 is adapted to the protruding length of the guide rods 111, and the inner wall of the grooves is smooth to achieve full coverage and shielding of the guide rods 111. The second tooling 300 has sealing rods 301 that correspond one-to-one with the number, arrangement, and inner diameter of the guide grooves 121 of the second fusion body 12. The length of the sealing rods 301 is adapted to the depth of the guide grooves 121 and can be completely inserted into the guide grooves 121 to achieve full sealing of the inner cavity.

[0069] During assembly, the second implant 14 of the first fusion body 11 is first aligned with the first tooling 200, so that the protruding guide rod 111 on the first fusion body 11 is precisely inserted into the corresponding relief groove 201 of the first tooling 200, until the mating surfaces of the first fusion body 11 and the first tooling 200 form a sealed limit, thus completing the assembly of the first fusion body 11 and the tooling; then the second implant 14 of the second fusion body 12 is aligned with the second tooling 300, so that the sealing rod 301 on the second tooling 300 is fully inserted into the corresponding guide groove 121 of the second fusion body 12, until the mating surfaces of the second fusion body 12 and the second tooling 300 form a sealed limit, thus completing the assembly of the second fusion body 12 and the tooling; after the two sets of tooling are assembled, only the large hole filling area of ​​the second implant 14 of the first fusion body 11 and the second fusion body 12 is exposed, and the remaining non-filled areas are completely covered and isolated by the tooling.

[0070] The first fixture 200 and the second fixture 300 are set up to achieve comprehensive sealing protection of the non-filled area. By fully wrapping the guide rod 111 with the clearance groove 201 and fully filling the guide groove 121 with the sealing rod 301, the piezoelectric elastic material 16 is prevented from seeping into the guide mating structure and adhering to the sliding mating surface of the guide rod 111 in the subsequent impregnation process. This avoids problems such as the guide rod 111 getting stuck with the guide groove 121, failure of mating accuracy, and limited opening stroke after the piezoelectric elastic material 16 solidifies, thus ensuring the smoothness and accuracy of the self-opening movement of the fusion device.

[0071] Because the mating surfaces of the two fused bodies 1 are curved, by setting the first tooling 200 and the second tooling 300 to contact the mating surfaces of the two fused bodies 1 respectively, the subsequent processing of the piezoelectric elastic material 16 at the mating surfaces can be reduced. At the same time, the stability of the fused body 1 in the piezoelectric elastic material 16 solution is ensured.

[0072] S2: Immerse the second implant 14 of the first fusion body 11 and the second fusion body 12 into a solution of piezoelectric elastic material 16, and wait for the piezoelectric elastic material 16 to solidify. In this step, the liquid level needs to be controlled to not exceed the preset red line, ensuring that only the macroporous structural area of ​​the second implant 14 is fully wetted and filled. After the piezoelectric elastic material 16 has fully penetrated into the pores of the second implant 14, allow it to stand and completely solidify, forming an elastic composite structure. Precisely controlling the liquid level ensures that the piezoelectric elastic material 16 fills only the macroporous area of ​​the second implant 14, providing a functional basis for piezoelectric power generation, avoiding material waste, and providing a physical barrier for subsequent directed bone cell growth.

[0073] S3: Remove the first fusion body 11 and the second fusion body 12, and process the excess piezoelectric elastic material 16 on the surfaces of the first fusion body 11 and the second fusion body 12; In step S3, after removing the first fusion body 11 and the second fusion body 12, remove the first tooling 200 and the second tooling 300, and then process the excess piezoelectric elastic material 16 on the surfaces of the first fusion body 11 and the second fusion body 12.

[0074] The piezoelectric elastic material 16 can be removed by wire cutting or sanding. Besides removing the piezoelectric elastic material 16 from the surface of the second implant 14, it can also be removed from the surface of the guide rod 111, inside the guide groove 121, and inside the receiving groove 112. Removing excess piezoelectric elastic material 16 avoids structural interference, ensures the insertion accuracy of the guide rod 111 and the guide groove 121, and prevents jamming during the unfolding process. Simultaneously, it ensures the flatness of the mating surface of the fusion body 1, providing a foundation for the stable bonding of the subsequent conductive layer 15 and the uniform transmission of electrical signals.

[0075] S4: A piezoelectric elastic material 16 is coated on one side of the conductive layer 15 and bonded to the side of the second implant 14 away from the first implant 13. A highly conductive coating or film is selected as the conductive layer 15, and a solution of the piezoelectric elastic material 16 is uniformly coated on the side facing the fusion body 1. Then, the conductive layer 15 is precisely bonded to the side of the second implant 14 away from the first implant 13, so that the conductive layer 15 forms an electrical connection with the piezoelectric elastic material 16 and the guide rod 111 in the second implant 14, while ensuring complete adhesion between the conductive layer 15 and the mating surface. The coating of the conductive layer 15 with the piezoelectric elastic material 16 can enhance the bonding force with the second implant 14 and prevent detachment; the electrical connection between the conductive layer 15, the piezoelectric elastic material 16, and the guide rod 111 constructs a complete electrical signal conduction path, which can stably transmit the microcurrent generated by the piezoelectric elastic material 16 to the mating surface, providing continuous electrical stimulation for the directional growth of bone cells. At the same time, the thin conductive layer 15 does not increase the additional volume, ensuring the fit of the fusion device implantation.

[0076] The installation method of the split-type fusion unit 100 of the present invention is as follows:

[0077] The bone fragments removed from the patient's intervertebral space are placed in the receiving slot 112, and the two fusion bodies 1 are docked and implanted into the patient's body. After implantation, the patient's vertebrae will recover to a certain extent, and then gradually return to their original height during the process of bone growth.

[0078] The split-type fusion device 100 of the present invention comprises two independent fusion bodies 1 that can abut against each other and are filled with piezoelectric elastic material 16, and a conductive layer 15 on the mating surface of the fusion bodies 1. The microcurrent generated by the piezoelectric elastic material 16 is transmitted through the conductive layer 15, which can accelerate the proliferation and differentiation of bone cells and improve the bone fusion efficiency. At the same time, the conductive layer 15 guides the bone cells to grow in a directional manner at the mating surface, promoting the gradual separation of the two fusion bodies 1, realizing the adaptive intervertebral height adjustment in vivo, and allowing the height adjustment and the bone fusion process to be completed simultaneously, solving the pain point that it is difficult to achieve both at the same time.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A split stent, characterized by: The split-type fusion device includes two independent fusion bodies configured to abut each other upon implantation. Each fusion body includes a conductive layer disposed on the side facing the other fusion body. The fusion body is filled with a piezoelectric elastic material, and the conductive layer is electrically connected to the piezoelectric elastic material. The two fusion bodies are a first fusion body and a second fusion body. At least two guide rods protrude from the first fusion body toward the second fusion body. At least two guide grooves are formed on the second fusion body for interlocking with the guide rods. The guide rods are made of conductive material and are electrically connected to the piezoelectric elastic material and the conductive layer within the fusion body. The conductive layer guides bone cells to grow directionally at the abutment surface, promoting the gradual separation of the two fusion bodies and achieving adaptive intervertebral height adjustment within the body.

2. The split-type fusion device according to claim 1, characterized in that: The conductive layer is one or more composite structures selected from conductive thin films, conductive metal sheets, and conductive fabrics.

3. The split-type fusion device according to claim 1, characterized in that: The piezoelectric elastic material is one of the following: polyvinylidene fluoride and its copolymers piezoelectric elastomers, medical polyurethane-based piezoelectric elastomers, biodegradable polyester-based piezoelectric elastomers, polyimide piezoelectric elastomers, and piezoelectric hydrogels.

4. The split-type fusion device according to claim 1, characterized in that: The fusion body includes a first implant and a second implant. The conductive layer is disposed on the side of the second implant away from the first implant. Both the first implant and the second implant have porous structures. The piezoelectric elastic material is disposed in the second implant.

5. The split-type fusion device according to claim 4, characterized in that: The average pore size of the first implant is smaller than that of the second implant.

6. The split-type fusion device according to claim 4, characterized in that: The first and second implants were fabricated using metal materials.

7. The split-type fusion device according to claim 1, characterized in that: The surface of the guide rod that contacts the piezoelectric elastic material has grooves.

8. The split-type fusion device according to claim 1, characterized in that: The surface of the guide rod has a hydrophobic structure.

9. The split-type fusion device according to claim 1, characterized in that: At least one of the fused bodies is recessed on one side facing the other fused body to form a receiving groove for receiving bone fragments.

10. The split-type fusion device according to claim 1, characterized in that: The mating surfaces of the two fused bodies are configured with bending matching.

11. A method for manufacturing a split-type fusion unit, used to manufacture the split-type fusion unit as described in any one of claims 1-10, characterized in that: The manufacturing method of the split-type fusion unit includes the following steps: S1: Fabricate the first implant and the second implant of the first fusion body and the second fusion body respectively, fabricate a guide rod, and insert the guide rod into the first fusion body; S2: Immerse the second implant of the first fusion body and the second fusion body into the piezoelectric elastic material solution and wait for the piezoelectric elastic material to solidify. S3: Remove the first fusion body and the second fusion body, and remove excess piezoelectric elastic material from the surfaces of the first fusion body and the second fusion body; S4: Coat one side of the conductive layer with a piezoelectric elastic material and bond it to the side of the second implant away from the first implant.

12. The manufacturing method of the split-type fusion device according to claim 11, characterized in that: Between steps S1 and S2, there is step S11: a first tooling and a second tooling are provided. The first tooling is provided with a clearance groove for inserting a guide rod, and the second tooling is provided with a sealing rod. The second implant of the first fusion body is assembled with the first tooling, and the guide rod is inserted into the clearance groove. The second implant of the second fusion body is assembled with the second tooling, and the sealing rod is inserted into the guide groove. In step S3, after the first fusion body and the second fusion body are taken out, the first tooling and the second tooling are removed, and then the excess piezoelectric elastic material on the surface of the first fusion body and the second fusion body is processed.

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