3D printing bone grafting-free window type porous tantalum metal interbody fusion cage

Abstract

The invention discloses a 3D printing bone grafting window-free porous tantalum metal interbody fusion cage which comprises a fusion cage body, the fusion cage body is integrally formed by machining medical-grade tantalum metal, and a clamping hole is formed in the front side of the fusion cage body and used for being connected with an operation instrument; the two groups of porous net racks are respectively fixed on the upper surface and the lower surface of the fusion cage body, the outer side surface of each porous net rack is a contact interface, and each contact interface is of an arc-shaped structure; bayonets are symmetrically formed in the inner wall of the front side of the fusion cage body, the clamping hole is formed between the bayonets, and the bayonets are used for limiting operation instruments. The porous tantalum material with high biological activity and high porosity is adopted, reliable spinal fusion can be achieved on the premise that bone grafting is not needed, the problems of bone taking trauma and donor region complications related to bone grafting and immunoreaction caused by allogeneic bone grafting are effectively solved, and therefore the occurrence risk of postoperative complications is reduced, and the bone grafting success rate is increased. The postoperative recovery process of the patient is improved.

Description

Technical Field

[0001] This invention relates to the field of spinal orthopedic implant technology, and in particular to a 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device. Background Technology

[0002] Interbody fusion cages are indispensable implants in spinal fusion surgery, playing a crucial role in interbody fusion. Commonly used interbody fusion cages are made of PEEK material; however, PEEK has poor bioactivity and does not easily integrate with human bone. Therefore, a bone grafting window is designed in the middle of the fusion cage for autologous / allogeneic bone transplantation. Interbody fusion can only be achieved through bone grafting. However, bone grafting carries many risks, and the fusion process is lengthy. During the incomplete fusion period, there are risks such as cage displacement and subsidence.

[0003] To address the aforementioned technical issues, this invention provides a 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device. Summary of the Invention

[0004] The purpose of this invention is to provide a 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a 3D-printed bone-graft-free, window-type porous tantalum metal interbody fusion device, comprising: The fusion device body is integrally formed from medical-grade tantalum metal, and a clamping hole is provided on the front side of the fusion device body for connecting with the operating instrument. A porous mesh frame is provided in two sets, and the two sets of porous mesh frames are respectively fixed on the upper and lower surfaces of the fusion body. The outer surface of the porous mesh frame is a contact interface, and the contact interface has an arc-shaped structure. The fusion unit body is integrally formed using selective laser melting technology; The porous mesh frame and the fusion unit body are integrally formed structures with no transition seams in between. The fusion device body has symmetrically arranged bayonets on the inner wall of the front side, and the clamping holes are arranged between the bayonets. The bayonets are used to limit the movement of the operating instruments.

[0006] The 3D-printed porous tantalum metal interbody fusion device without bone grafting window provided by the present invention has a closed structure on the sidewall of the fusion device body without bone grafting window.

[0007] The 3D-printed bone-graft-free window-type porous tantalum metal interbody fusion device provided by the present invention has a porous mesh frame that is a trabecular porous structure with interconnected pores, a pore size range of 400–600 μm, and a porosity of 60%–80%.

[0008] The 3D-printed bone-graft-free window-type porous tantalum metal interbody fusion device provided by the present invention has a roughened contact interface and an arc shape matching the vertebral endplate.

[0009] The 3D-printed bone-graft-free window-type porous tantalum metal interbody fusion device provided by the present invention has a microstructure on the contact interface that enhances mechanical interlocking, the microstructure including at least one of microprotrusions, meshes or microgrooves.

[0010] The 3D-printed bone-graft-free window-type porous tantalum metal intervertebral fusion device provided by the present invention is integrally formed by selective laser melting technology.

[0011] The 3D-printed bone-graft-free window-type porous tantalum metal intervertebral fusion device provided by the present invention has a porous mesh frame and the fusion device body as an integrally formed structure.

[0012] The 3D-printed bone-graft-free window-type porous tantalum metal interbody fusion device provided by the present invention has anti-slip textures on the inner wall of the bayonet to enhance the limiting stability with the operating instruments.

[0013] The present invention discloses the following technical effects: The fusion device of this invention eliminates the bone graft window found in traditional fusion devices. By optimizing the overall structure, it achieves uniform load distribution and a larger contact area with the endplate, thereby improving segmental stability. The main body of the fusion device adopts a trabecular porous structure with interconnected pores. This structure is precisely manufactured using 3D printing technology, possesses excellent mechanical properties, and can provide an in-situ scaffold for early bone tissue, effectively inducing bone ingrowth and bone bridge formation.

[0014] This invention utilizes porous tantalum material with high bioactivity and high porosity, enabling reliable spinal fusion without the need for bone grafting. This effectively avoids bone grafting-related issues such as bone harvesting trauma, donor site complications, and immune reactions caused by allogeneic bone grafting, thereby reducing the risk of postoperative complications and improving the patient's postoperative recovery process. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a front view of the 3D-printed porous tantalum metal interbody fusion device without bone grafting according to the present invention. Figure 2This is a top view of the 3D-printed porous tantalum metal interbody fusion device without bone grafting according to the present invention. Figure 3 This is a schematic diagram of the internal structure of the 3D-printed bone-graft-free window-type porous tantalum metal interbody fusion device of the present invention. Figure 4 This is an isometric view of the 3D-printed porous tantalum metal interbody fusion device without bone grafting according to the present invention.

[0017] The components include: 1. Fusion unit body; 2. Space frame; 3. Bayonet; 4. Clamping hole. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1-4 This invention provides a 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device, comprising: Fusion device body 1 is integrally formed from medical-grade tantalum metal. The front side of fusion device body 1 is provided with clamping hole 4 for connecting with operating instruments. The porous mesh frame 2 has two sets, and the two sets of porous mesh frames 2 are fixed on the upper and lower surfaces of the fusion body 1 respectively. The outer surface of the porous mesh frame 2 is the contact interface, and the contact interface has an arc-shaped structure. Among them, the inner wall of the front side of the fusion device body 1 is symmetrically provided with bayonets 3, and clamping holes 4 are provided between the bayonets 3. The bayonets 3 are used to limit the operation of the instrument.

[0021] In this embodiment, the surgical procedure for a 3D-printed, bone-graft-free, porous tantalum metal interbody fusion cage (taking the lumbar TLIF approach as an example) includes the following steps: Step 1: Preoperative preparation; Imaging assessment: Measure the height, width and depth of the target intervertebral space using CT or MRI, and select a fusion device with a matching size based on the measurement results (ensuring that the porous mesh frame 2 can completely cover the stress area of ​​the endplate).

[0022] Instrument adaptation: Connect the special operating instrument (clamp with buckle) to the clamping hole 4 on the front side of the fusion unit, and limit it through the bayonet 3 (to prevent the instrument from rotating and shifting), and confirm that the connection is secure.

[0023] Patient positioning: The patient should lie prone with a pillow under the lower back to maintain the physiological lordosis of the lumbar spine, which will facilitate subsequent intervertebral disc opening procedures.

[0024] Step 2: Exposure of the surgical field; The skin, subcutaneous tissue and deep fascia are incised layer by layer through the posterior or intervertebral foramen approach to expose the lamina and articular processes of the target vertebral body. If the TLIF approach is used, part of the superior articular process needs to be removed to expand the field of vision of the intervertebral foramen. During the operation, care should be taken to protect the nerve roots and dural sac to avoid damage.

[0025] Step 3: Intervertebral disc treatment; Intervertebral discectomy: Using nucleus pulposus forceps and curettes, the diseased intervertebral disc tissue (including annulus fibrosus and nucleus pulposus) in the target intervertebral space is thoroughly removed to expose the endplates of the superior and inferior vertebral bodies.

[0026] Endplate trimming: Gently scrape the surface cartilage of the endplate with an endplate curette (preserving the subchondral bone) to create a rough surface, which will facilitate the fusion of the porous tantalum framework 2 with the bone tissue.

[0027] Intervertebral space opening: The intervertebral space is opened appropriately using an intervertebral space opener to restore normal height and reserve space for fusion cage implantation.

[0028] Step 4: Fusion device implantation; Instrument positioning: Align the fusion device with the connected operating instruments with the intervertebral space entrance, ensuring that the outer side (arc contact interface) of the porous mesh frame 2 faces the endplate. The rotation of the instrument is restricted by the locking mechanism of the locking slot 3, ensuring operational stability.

[0029] Precise insertion: Under the guidance of C-arm fluoroscopy (anteroposterior and lateral views), the fusion device is slowly pushed into the intervertebral space to ensure that the arc-shaped contact interface is fully in line with the curvature of the endplate (anteroposterior fluoroscopy ensures centering, lateral fluoroscopy avoids warping) and avoids local stress concentration.

[0030] Instrument disengagement: After confirming that the fusion device is in a stable position (no loosening or nerve compression), loosen the connection between the operating instrument and clamping hole 4 and remove the instrument.

[0031] Step 5: Assist in fixation; If it is a single-segment fusion or the patient has good bone density, fixation can be achieved by relying on the stability of the fusion device itself; if it is a multi-segment fusion or the patient has osteoporosis, it is necessary to combine it with the pedicle screw system for fixation to enhance immediate stability.

[0032] Step Six: Close the surgical field Irrigate the surgical field, remove any remaining tissue debris, and place a drainage tube to prevent hematoma formation.

[0033] The muscles, fascia, and skin are sutured layer by layer to close the surgical incision.

[0034] Further optimization of the design resulted in a closed structure on the sidewall of the fusion device body 1, without any bone grafting windows.

[0035] Further optimization of the scheme: the porous grid 2 is a small beam-like porous structure with interconnected pores, a pore size range of 400–600 μm, and a porosity of 60%–80%.

[0036] The design was further optimized by roughening the contact interface and making its outline an arc shape that matches the vertebral endplate.

[0037] The design is further optimized by incorporating a microstructure at the contact interface to enhance mechanical interlocking. The microstructure includes at least one of microprotrusions, meshes, or microgrooves.

[0038] The scheme was further optimized, and the fusion body 1 was integrally formed by selective laser melting technology.

[0039] The scheme was further optimized so that the porous mesh frame 2 and the fusion body 1 are integrally formed.

[0040] The design has been further optimized by adding anti-slip textures to the inner wall of the bayonet 3 to enhance the stability of the device in terms of positioning.

[0041] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0042] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device, characterized in that, include: The fusion device body (1) is integrally formed from medical-grade tantalum metal. The front side of the fusion device body (1) is provided with a clamping hole (4) for connecting with the operating instrument. The porous mesh frame (2) is provided in two sets. The two sets of porous mesh frames (2) are respectively fixed on the upper and lower surfaces of the fusion body (1). The outer surface of the porous mesh frame (2) is the contact interface, and the contact interface is an arc-shaped structure. The fusion unit body (1) is integrally formed by selective laser melting technology; The porous mesh frame (2) and the fusion body (1) are integrally formed structures with no transition seam in the middle; The fusion device body (1) has symmetrically arranged bayonets (3) on the inner wall of the front side, and the clamping holes (4) are arranged between the bayonets (3). The bayonets (3) are used to limit the operation of the device.

2. The 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device according to claim 1, characterized in that, The sidewall of the fusion device body (1) is a closed structure and no bone graft window is provided.

3. The 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device according to claim 1, characterized in that, The porous mesh frame (2) is a small beam-like porous structure with interconnected pores. The pore size ranges from 400 to 600 μm, and the porosity is 60% to 80%.

4. The 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device according to claim 1, characterized in that, The contact interface is roughened and its outline is an arc shape that matches the vertebral endplate.

5. A 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device according to claim 3, characterized in that, The contact interface is provided with microstructures to enhance mechanical interlocking, the microstructures including at least one of microprotrusions, meshes or microgrooves.

6. The 3D-printed, bone-graft-free, window-type porous tantalum metal interbody fusion device according to claim 1, characterized in that, The inner wall of the bayonet (3) is provided with anti-slip texture to enhance the limiting stability with the operating instrument.

Images