D-shaped hollow columnar thoracolumbar vertebra side wall interbody fusion cage for rachitis surgery

Abstract

The invention provides a D-shaped hollow cylindrical thoracolumbar vertebra side wall interbody fusion cage for a rachitis operation, which belongs to the technical field of medical instruments for spine surgery, is an integrally formed rigid structure without movable parts, is a D-shaped hollow cylindrical body on the whole, and comprises a fusion cage cylindrical body with a fixed height, the cross section of a main body is D-shaped, and the cross section of the main body is L-shaped; the upper end face and the lower end face of an arc-shaped side wall and a plane side wall are enclosed by the upper end face and the lower end face; the cylindrical hollow cavity penetrates through the fusion cage cylindrical body in the axial direction, and the micron-sized rough textures are arranged on the outer surfaces of the arc-shaped side wall and the plane side wall. Anatomical matching with the lateral bone surface of the vertebral body is achieved through the D-shaped section, and load transmission and stress distribution are fundamentally improved in combination with large-area contact between the planar side wall and the end plate. Unprecedented initial stability is provided for the fusion cage in infectious loose bone, and the risks of displacement, sedimentation and disengagement are remarkably reduced.

Description

Technical Field

[0001] This application belongs to the field of spinal surgery medical device technology, specifically relating to a D-shaped hollow cylindrical thoracolumbar intervertebral fusion device for spinal inflammation surgery. Background Technology

[0002] Suppurative spondylitis is an inflammatory disease of the spine caused by bacterial infection. Its pathological process includes the destruction of vertebral bodies and intervertebral discs, often leading to severe narrowing of the intervertebral space, loss of spinal stability, nerve compression, and even life-threatening complications such as sepsis. Therefore, for patients with suppurative spondylitis, the goals of surgical intervention mainly include: thoroughly removing infected and necrotic tissue, restoring the physiological sequence and stability of the spine, and ultimately achieving firm bony fusion between the affected vertebrae.

[0003] Interbody fusion cages are the core implants in spinal fusion surgery, primarily functioning to maintain intervertebral disc height, provide initial stability, and offer space and support for bone fusion. However, existing interbody fusion cages conventionally used in the thoracolumbar spine (such as round, square, and kidney-shaped cross-section cages) have revealed a series of technical shortcomings when applied to the specific scenario of purulent spondylitis: Insufficient morphological fit and stability: Traditional round or square cross-section fusion cages have poor conformity to the bony contours (usually curved surfaces with a certain curvature) of the thoracic and lumbar vertebral bodies. This mismatch results in a small contact area between the fusion cage and the host bone after implantation, leading to stress concentration and a high risk of displacement and subsidence postoperatively. This risk is particularly pronounced in patients with purulent spondylitis whose vertebral bone is porous or destroyed due to infection, potentially causing surgical failure and requiring revision surgery.

[0004] Structural design is not conducive to infection control: Some fusion devices are designed with complex, height-adjustable mechanical structures (such as expandable or threaded adjustable types) to accommodate different intervertebral disc heights. These structures have splicing gaps or cavities, and in an infected environment, necrotic tissue and bacteria can easily remain and proliferate in these hard-to-clean areas, becoming the root cause of postoperative infection recurrence or persistence.

[0005] Low bone fusion efficiency: Some fusion devices have unreasonable hollow structure designs, small internal space or poor bone conduction channels, which are not conducive to the implantation of sufficient autologous bone and the ingrowth and creeping replacement of new bone, resulting in poor integration of bone-fusion device interface, prolonged fusion cycle, and even the formation of pseudo-arthrosis.

[0006] Therefore, there is an urgent need for a new type of interbody fusion device that can fundamentally solve the above problems and provide patients with purulent spondylitis with an optimized surgical solution that can achieve thorough debridement, immediate stability, efficient fusion, and low risk of infection. Summary of the Invention

[0007] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0008] Therefore, this application designs a D-shaped hollow cylindrical thoracolumbar intervertebral fusion device for spinal surgery. This solution addresses issues such as insufficient postoperative stability, high risk of residual infection, low bone fusion efficiency, and lack of adaptability to infection environments.

[0009] In a first aspect, this application provides a D-shaped hollow cylindrical intervertebral fusion cage for spinal surgery, which is a rigid structure integrally formed without any moving parts, and is in the shape of a "D"-shaped hollow cylinder, comprising: A fusion device column with a fixed height, the main body having a "D" shaped cross-section, and being enclosed by two upper and lower end faces of an arc-shaped sidewall and a planar sidewall; A cylindrical hollow cavity is provided that extends through the axial direction of the columnar body of the fusion device; Micron-level rough textures are provided on the outer surfaces of the arc-shaped sidewalls and planar sidewalls, and annular anti-slip teeth are provided on the upper and lower end faces of the fusion vessel column. At least two through-holes are formed on the arc-shaped sidewall and communicate with the hollow cavity; Osteoconductive structures, located on the inner wall of the hollow cavity, are used to guide bone growth.

[0010] Furthermore, the radius of curvature of the arc-shaped sidewall is 15-22 mm.

[0011] Furthermore, the height of the fusion device column is a fixed specification of 8mm, 10mm, 12mm or 14mm.

[0012] Furthermore, the diameter of the hollow cavity accounts for 40%-60% of the maximum diameter of the fusion vessel column.

[0013] Furthermore, the axis of the through-hole forms an angle of 30°-45° with the axis of the columnar body of the fusion device.

[0014] Furthermore, the bone conduction structure consists of 3-4 evenly distributed, axially extending bone conduction grooves.

[0015] Furthermore, the depth of the bone conduction groove is 2-3 mm and the width is 3-4 mm.

[0016] Furthermore, the fusion device column is made of medical-grade titanium alloy or antibacterial modified polyetheretherketone material.

[0017] Furthermore, when the fusion device column is made of medical-grade titanium alloy, its surface is provided with a titanium oxide antibacterial coating.

[0018] Secondly, this application provides the use of interbody fusion devices in the preparation of surgical instruments for thoracolumbar interbody fusion for the treatment of suppurative spondylitis.

[0019] Compared with the prior art, the technical solution provided in this application has at least the following beneficial effects: This invention achieves anatomical matching with the lateral bone surface of the vertebral body through a "D"-shaped cross-section, combined with large-area contact between the planar sidewall and the endplate, fundamentally improving load transfer and stress distribution. The micron-level rough texture of the outer surface provides a high-friction interface, while the annular anti-slip teeth on the end face achieve active intraosseous anchoring. This triple anti-slip mechanism of "surface fit + textured interlocking + toothed anchoring" provides unprecedented initial stability for the fusion device in infected osteoporotic bone, significantly reducing the risk of displacement, subsidence, and dislocation, creating a stable mechanical environment for early bone healing. The integrated fixed height design eliminates the complex cavities and gaps caused by adjustable components, preventing "dead zones" where bacteria can hide. The unique through-hole drainage design not only allows for high-pressure pulse irrigation during surgery to thoroughly remove residual infectious material outside the field of vision, but also serves as a drainage channel postoperatively to continuously drain any exudate or residual pus. This achieves infection control from the perspective of implant structural design. Furthermore, the osteoconductive structure of the inner wall provides a clear "track" and a large surface area for new bone ingrowth, effectively guiding new bone growth from both ends towards the center and enhancing the mechanical interlocking between the bone and the implant. This significantly improves the speed and success rate of bone fusion. The fixed-height, integrated structure ensures the overall mechanical strength of the implant, providing reliable support for damaged vertebrae. For materials, medical-grade titanium alloys / PEEK with inherent antibacterial properties or those capable of being coated with antibacterial agents can be selected, resulting in better biocompatibility and long-term safety in infected environments.

[0020] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the arc-shaped sidewall structure of the present invention; Figure 3 This is a schematic diagram of the planar sidewall structure of the present invention; Figure 4 This is a schematic diagram of the tail end structure of the present invention; Figure 5 This is a schematic diagram of the front end structure of the present invention.

[0022] Figure label: Fusion device column 1, arc-shaped sidewall 11, planar sidewall 12, hollow cavity 2, bone conduction groove 21, anti-slip teeth 3, through-type drainage hole 4. Detailed Implementation

[0023] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0025] The following reference Figures 1 to 5 This application describes a D-shaped hollow cylindrical thoracolumbar interbody fusion device for spinal surgery, provided according to some embodiments.

[0026] A D-shaped hollow cylindrical intervertebral fusion cage for spinal surgery is a rigid, one-piece structure with no moving parts. The overall structure is a D-shaped hollow cylinder, comprising: a fusion cage cylinder 1 with a fixed height, the cross-section of which is D-shaped and enclosed by two upper and lower end faces of an arc-shaped sidewall 11 and a planar sidewall 12; a cylindrical hollow cavity 2 extending axially through the fusion cage cylinder 1; micron-level rough textures on the outer surfaces of the arc-shaped sidewall 11 and the planar sidewall 12; and annular anti-slip teeth 3 on the upper and lower end faces of the fusion cage cylinder 1; at least two through-holes 4 on the arc-shaped sidewall 11 communicating with the hollow cavity 2; and a bone conduction structure on the inner wall of the hollow cavity 2 for guiding bone growth. The radius of curvature of the arc-shaped sidewall 11 is 15-22 mm. The height of the fusion device column 1 is a fixed specification of 8mm, 10mm, 12mm, or 14mm. The diameter of the hollow cavity 2 accounts for 40%-60% of the maximum diameter of the fusion device column 1. The axis of the through-hole 2 forms an angle of 30°-45° with the axis of the fusion device column 1. The bone conduction structure consists of 3-4 evenly distributed axially extending bone conduction grooves 21. The depth of the bone conduction grooves 21 is 2-3mm, and the width is 3-4mm. The fusion device column 1 is made of medical-grade titanium alloy or antibacterial modified polyetheretherketone material. When the fusion device column 11 is made of medical-grade titanium alloy, its surface is coated with a titanium oxide antibacterial coating.

[0027] Example 1: A "D"-shaped hollow columnar fusion device based on 3D printed titanium alloy This embodiment provides a lateral interbody fusion device specifically designed for adult lower thoracic (T10-T12) or lumbar (L1-L5) spondylitis surgery, such as... Figures 1 to 5 As shown.

[0028] 1. Materials and Manufacturing Processes: The fusion vessel column 1 is made from medical-grade Ti6Al4V ELI (ultra-low gap element) titanium alloy powder conforming to international standards ISO 5832-3 and ASTM F136. It is manufactured as a single piece using selective laser melting (SLM) 3D printing technology. SLM technology can precisely melt metal powder layer by layer, directly creating integrated parts with complex shapes and fine internal structures, completely avoiding seams or welding weaknesses that may occur with traditional machining. After printing, the fusion vessel undergoes rigorous heat treatment (such as hot isostatic pressing) to eliminate internal stress and improve material density. Subsequently, the molded part undergoes comprehensive post-processing: including removal of the support structure, sandblasting (using alumina or zirconium oxide abrasive) to remove surface powder and form a uniform micron-level roughness, and finally anodizing. The anodizing process is carried out under specific electrolyte and voltage conditions, forming a dense, porous titanium oxide (TiO2) coating with a thickness of approximately 5 to 10 micrometers on the titanium alloy surface. This coating not only improves surface biocompatibility, but also endows the implant surface with the potential ability to inhibit or kill bacteria due to its certain photocatalytic activity (it can generate reactive oxygen species under specific wavelength light), which is of great significance for infectious environments.

[0029] 2. Macroscopic morphology and geometric parameters: The fusion device is a hollow "D"-shaped column with an axial length L of 25 mm. This length is suitable for most single-segment fusions of the thoracic and lumbar spine.

[0030] Cross-sectional design: The cross-section features a unique "D" shape. The radius of curvature R of the arc-shaped sidewall 11 is designed to be 18 mm. This value is based on the median value derived from a statistical analysis of over 200 adult thoracic and lumbar spine CT data, ensuring excellent anatomical fit with the lateral arc-shaped bone surface of the vertebral body in most patients, forming a broad contact area. The width W of the planar sidewall 12 is 18 mm, and after implantation, it is parallel to and closely adheres to the endplates of the superior and inferior vertebral bodies, providing a stable support base.

[0031] Height Design: The fusion unit's height H is 10 mm, a fixed, non-adjustable value. This product line offers four standard height specifications: 8 mm, 10 mm, 12 mm, and 14 mm. Clinicians need to accurately measure the estimated height of the target intervertebral space after distraction and reduction based on preoperative CT or MRI images and select the closest specification. This "pre-selection-implantation" model completely eliminates the complex internal mechanisms such as screw drives and hinge opening and closing relied upon by traditional adjustable fusion units, thereby eradicating the risks of micromovement, wear, and breakage that may arise from these mechanisms, and most importantly—eliminating internal gaps and cavities where bacteria and necrotic tissue can hide.

[0032] 3. Detailed Explanation of Core Functional Structure: Bone graft and bone conduction space (hollow cavity 2): A cylindrical hollow cavity 2 with a diameter of D_c = 14 mm runs axially through the center of the fusion cage. Calculations show that its internal volume accounts for approximately 50% of the total volume of the fusion cage, providing ample space for the bone graft material. Three axial bone conduction grooves 21, each 2.5 mm deep and 3.5 mm wide, are evenly distributed on the inner wall of the cavity. These grooves 21 extend from one opening to the other, running the entire length of the cavity. Their working principle and beneficial effect are as follows: when prepared autologous cancellous bone particles (usually taken from the iliac bone) are tightly filled into the hollow cavity 2 during surgery, these grooves 21 form a continuous, regularly arranged "channel network" within the bone graft and at the bone-metal interface. During postoperative bone healing, new blood vessels and osteogenic progenitor cells from the cancellous bone of the upper and lower vertebral bodies preferentially migrate and proliferate towards the central region of the fusion cage along the grooves rich in osteoinducible factors and blood supply, following the path of low mechanical resistance and high surface area / volume ratio. This "guided bone ingrowth" pattern significantly accelerates the speed at which new bone penetrates the entire fusion cage compared to random growth within smooth-walled cavities. More importantly, once the newly formed bone tissue has mineralized and fully filled the grooves, a robust three-dimensional mechanical interlocking structure is formed between the titanium alloy inner wall and the bone tissue, similar to multiple "tenons" inserted into "mortises," greatly enhancing the interface's shear and torsional resistance. This effectively prevents bone resorption and fusion failure caused by long-term micromovement, laying a solid foundation for long-term biomechanical stability.

[0033] Surface anti-slip and anchoring system: The outer surfaces of the fusion device (arc sidewall 11 and planar sidewall 12) are sandblasted to form a uniform rough texture with an arithmetic mean roughness Ra ≈ 4.0 micrometers. This micro-roughness not only significantly increases the actual contact area and improves static friction, but also provides an ideal microenvironment for early osteoblast attachment and extracellular matrix deposition, which is beneficial for early biological fixation.

[0034] On the arc-shaped sidewall 11 and the planar sidewall 12, four concentric rings of anti-slip teeth 3 are precisely machined. Each anti-slip tooth 3 is a sharp, four-sided pyramidal shape with a tooth height of approximately 1.2 mm and a distance (tooth pitch) between adjacent teeth of approximately 2 mm. Its implantation mechanism and core function are as follows: During the procedure, a specialized implantation instrument is used to hold the fusion device and place it into the thoroughly cleaned and leveled intervertebral space, embedding it into place through precise tapping. During this process, the sharp tips of the anti-slip teeth 3 pierce and wed into the relatively soft cancellous bone beneath the vertebral endplate under pressure. This "piercing anchoring" generates immediate and strong anti-slip resistance. Especially for vertebrae with osteoporosis and decreased bone load-bearing capacity due to inflammation and infection, the pressure and friction of the endplate alone are insufficient. The active, embedded anchoring force provided by the anti-slip teeth 3 is one of the most effective mechanisms to prevent the fusion cage from shifting in the anterior-posterior (sagittal) or lateral (coronal) direction within the intervertebral space (i.e., the clinically common "displacement").

[0035] Key design features for infection control – through-hole 4: One of the most targeted and innovative features of this embodiment is the two through-holes 4 opened on the arc-shaped sidewall 11. The two holes are evenly distributed along the long axis of the fusion device, about 8 mm from the beginning and end of the device, respectively, with a diameter of 2.5 mm, and are completely connected to the hollow cavity 2 to form an open channel.

[0036] Its dual clinical functions and remarkable effects are as follows: Thorough intraoperative debridement: Before or after implantation of the fusion cage, when the main lesion area has been cleared but there is concern about residual necrotic material in the posterior or lateral corners of the fusion cage, the surgeon can insert a thin irrigation cannula (such as a syringe needle or a dedicated irrigation head) into one of the through-holes 4. High-pressure pulse irrigation is applied, and saline or antibiotic-containing irrigation solution can be injected at high speed into the hollow cavity 2 and the dead-angle area on the dorsal side of the fusion cage through this hole. The powerful fluid dynamics can flush away hidden micro-bone debris, necrotic interstitial tissue, and bacterial biofilm, carrying them out through another through-hole 4 or from the openings at both ends of the hollow cavity 2. This "through-hole irrigation" achieves targeted deep cleaning of the "blind spot" around the implant beyond visualization, which is completely impossible with traditional solid fusion cages or designs with only lateral blind holes, greatly improving the thoroughness of debridement.

[0037] Postoperative continuous drainage: Before closing the surgical incision, the surgeon can gently insert the end of a thin, flexible silicone drainage tube or strip through a through-hole 4 into the hollow cavity 2 or attach it to the opening. Postoperatively, any small amount of bleeding, inflammatory exudate, or, in extremely rare cases, residual infectious secretions that may occur locally can be continuously and smoothly drained out of the body along this built-in drainage channel provided by the fusion device's own structure. This avoids the accumulation of fluid around the fusion device, forming a "pool," which is an ideal culture medium for bacterial growth and a common cause of infection recurrence or wound complications. Therefore, this design transforms the interbody fusion device from a passive "foreign body" into a "functional implant" that can actively participate in postoperative infection and exudate management.

[0038] 4. Brief description of clinical application process: During the surgery, the affected segment is first exposed via a lateral approach (such as OLIF, XLIF, or anterior lateral approach). The infected intervertebral disc, necrotic and softened endplate, and diseased bone are thoroughly removed until fresh, bleeding, healthy cancellous bone beds are exposed above and below the vertebral bodies. Based on preoperative planning and intraoperative measurements, a 10 mm high fusion device of this invention is selected from a range of products. Prepared bone graft material (such as autologous iliac bone cancellous particles rich in osteoblasts and growth factors; in high-risk cases, it can be mixed with antibiotic powder such as vancomycin) is tightly packed into the hollow cavity 2 and bone conduction groove 21 of the fusion device. The fusion device is held in place using the matching implanter and inserted into the intervertebral space along the surgical channel. Care must be taken regarding orientation during implantation: the curved sidewall 11 faces the lateral cortical bone surface of the vertebral body for optimal fit; the planar sidewall 12 faces the spinal canal (i.e., medially) to avoid compression of the neural structures within the spinal canal. Under fluoroscopic monitoring, gently tap the implanter until the fusion device reaches the desired depth, at which point the anti-slip teeth 3 should be embedded in the endplate. Final flushing can then be performed again through the through-hole 4. After placing the drainage tube / strip as needed, a lateral plate or rod system can be installed to complete segmental fixation. The drainage tube / strip is removed 24-48 hours post-operation, depending on the drainage volume.

[0039] Example 2: Antibacterial modified PEEK fusion vessel with inclined drainage holes This embodiment provides another implementation method with optimized material selection and details.

[0040] This embodiment is basically the same as Embodiment 1 in terms of the core "D"-shaped main structure, hollow cavity 2, bone conduction groove 21, and anti-slip teeth 3 design. The main difference is: Materials: The fusion cage column 1 is manufactured using carbon fiber reinforced antibacterial modified polyetheretherketone (CFR-PEEK) via precision injection molding. Trace amounts of nano-silver ions or organic quaternary ammonium salt antibacterial agents are pre-dispersed uniformly within the PEEK substrate. This material offers two major advantages: First, its elastic modulus (typically approximately 15-20 GPa) is closer to that of human cortical bone (approximately 10-20 GPa), reducing the "stress shielding" effect caused by excessive implant stiffness, which is beneficial for long-term bone remodeling and maintaining bone density. Second, PEEK is radiolucent, and during postoperative X-ray or CT scans, it does not produce severe artifacts like those found in metal, allowing physicians to more clearly observe the bone graft fusion within the fusion cage and changes at its interface with the adjacent vertebral bodies, facilitating early assessment of fusion progress.

[0041] Drainage hole optimization design: In this embodiment, the through drainage hole 41 is designed as an inclined type. The angle θ between its central axis and the long axis of the fusion vessel column 1 is approximately 45°.

[0042] This tilted design offers several benefits: Fluid dynamics optimization: The inclined channels alter the direction of the irrigation fluid as it flows in and out, making it easier to create eddies or turbulence within the hollow cavity 2. This fluid movement pattern has stronger shear and scouring forces than straight-in-straight laminar flow, enabling it to more effectively peel off and remove contaminants adhering to the cavity walls or bone graft surfaces, resulting in higher debridement efficiency.

[0043] Reduced stress at the bone interface: The angled edge of the orifice contacts the curved surface of the vertebral body at an oblique angle, creating an elliptical contact area rather than the sharp, rounded edge formed by a straight orifice. This disperses contact stress, avoiding the localized stress concentration, microfractures, or cutting effects that a sharp edge of a straight orifice might cause to the already weakened vertebral cortex due to infection, thus better aligning with the concept of protective support.

[0044] Facilitates drainage procedures: The inclined channel provides a more natural and smooth angle for placing drainage tubes / strips during surgery and adjusting them after surgery. The drainage fluid also collects and flows out more easily along the inclined surface due to gravity, ensuring the patency of the drainage system.

[0045] Alternative solutions and examples (diversified design of bone conduction structures) The bone conduction structure of this invention is not limited to the form of the axial bone conduction groove 21. Those skilled in the art can make equivalent transformations according to different clinical needs (such as special requirements for rotational stability or extreme requirements for structural strength). The following are two feasible alternatives, whose core principles of promoting bone fusion and enhancing interface locking remain unchanged: Option A: Spiral bone conduction groove In this alternative, continuous threaded bone conduction grooves are machined into the inner wall of the hollow cavity 2. The threads can be single-start or multi-start, preferably with a pitch of about 4.5 mm and a groove depth of about 2.5 mm.

[0046] Advantages: Excellent rotational stability: The threaded structure provides a 360-degree continuous anti-rotation surface. As new bone grows into the grooves of the thread, it forms a "screw-nut" mechanical lock, which can very effectively resist the rotational micromovements that may occur in the fusion cage within the intervertebral space. This is especially important for some cases with lateral slippage or instability.

[0047] Extra-long bone growth guiding surface: After the threads are unfolded, they form a very long spiral line, which greatly increases the effective contact area of ​​the bone-implant interface and provides more space for bone integration.

[0048] Good bone graft retention: The threaded grooves help to better retain the bone graft material in the cavity during implantation, preventing it from falling out prematurely.

[0049] Option B: Built-in axial support ribs In this design, inside the hollow cavity 2, several (e.g., 2-4) axially extending support ribs are integrally formed with the fusion cylinder 1. The cross-sections of these support ribs can be circular, cross-shaped, or wing-shaped, and they divide the hollow cavity into several interconnected small chambers in cross-section.

[0050] Advantages: Significantly enhanced structural strength: The supporting ribs act as "reinforcing ribs," greatly improving the hollow column's ability to resist axial compressive and bending loads, preventing collapse or deformation of the cavity wall under extremely high loads. This is extremely valuable for revision surgeries or severe cases involving severe bone defects where the implant needs to bear the majority of the load.

[0051] Multi-directional trabecular bridges: The supporting ligaments themselves become the "core" or "skeleton" for the growth of new bone tissue. New bone can not only grow along the cavity wall, but also cross from one vertebra to another using the supporting ligaments as "bridges" or "guide columns," accelerating the connection and network formation of trabeculae in three-dimensional space, which is especially beneficial for promoting the central fusion of large bone defect areas.

[0052] Increased interface locking points: As new bone grows around the supporting ligament, multiple additional mechanical anchoring points are formed that penetrate deep into the implant, further consolidating the integrity of the bone-implant complex.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0054] In this application, it should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" 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 this application and 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 this application.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0056] In this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" 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. The term "multiple" refers to two or more, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0058] In this application, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A D-shaped hollow cylindrical intervertebral fusion cage for spinal surgery, comprising a rigid, integrally molded structure with no moving parts, and an overall "D"-shaped hollow cylindrical body, characterized in that... include: A fusion device column with a fixed height, the main body having a "D" shaped cross-section, and being enclosed by two upper and lower end faces of an arc-shaped sidewall and a planar sidewall; A cylindrical hollow cavity is provided that extends through the axial direction of the columnar body of the fusion device; Micron-level rough textures are provided on the outer surfaces of the arc-shaped sidewalls and planar sidewalls, and annular anti-slip teeth are provided on the upper and lower end faces of the fusion vessel column. At least two through-holes are formed on the arc-shaped sidewall and communicate with the hollow cavity; Osteoconductive structures, located on the inner wall of the hollow cavity, are used to guide bone growth.

2. The D-shaped hollow cylindrical thoracolumbar intervertebral fusion cage for spinal inflammation surgery according to claim 1, characterized in that, The radius of curvature of the arc-shaped sidewall is 15-22 mm.

3. The D-shaped hollow cylindrical thoracolumbar intervertebral fusion cage for spinal inflammation surgery according to claim 1, characterized in that, The height of the fusion device column is a fixed specification of 8mm, 10mm, 12mm or 14mm.

4. The D-shaped hollow cylindrical thoracolumbar interbody fusion device for spinal inflammation surgery according to claim 1, characterized in that, The diameter of the hollow cavity is 40%-60% of the maximum diameter of the fusion device column.

5. The D-shaped hollow cylindrical thoracolumbar interbody fusion device for spinal inflammation surgery according to claim 1, characterized in that, The axis of the through-hole forms an angle of 30°-45° with the axis of the columnar body of the fusion device.

6. The D-shaped hollow cylindrical thoracolumbar interbody fusion cage for spinal inflammation surgery according to claim 1, characterized in that, The bone conduction structure consists of 3-4 evenly distributed, axially extending bone conduction grooves.

7. A D-shaped hollow cylindrical interbody fusion cage for thoracic and lumbar lateral wall fusion in spinal surgery according to claim 6, characterized in that, The depth of the bone conduction groove is 2-3 mm and the width is 3-4 mm.

8. A D-shaped hollow cylindrical thoracolumbar interbody fusion device for spinal inflammation surgery according to any one of claims 1 to 7, characterized in that, The fusion device column is made of medical-grade titanium alloy or antibacterial modified polyetheretherketone material.

9. A D-shaped hollow cylindrical thoracolumbar interbody fusion device for spinal inflammation surgery according to claim 8, characterized in that, When the fusion device column is made of medical-grade titanium alloy, its surface is coated with a titanium oxide antibacterial coating.

10. The use of an interbody fusion device as described in any one of claims 1-9 in the preparation of a surgical instrument for thoracolumbar interbody fusion for the treatment of suppurative spondylitis.

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