Lumbar vertebra posterior fusion cage

Abstract

The invention relates to a lumbar posterior fusion cage which comprises a middle block body, a first edge block body and a second edge block body, a first through groove and a second through groove which are vertically through are formed in the symmetrical side faces of the middle block body respectively, a first clamping hole is formed in the middle of the first through groove, and a second clamping hole is formed in the middle of the second through groove; a first connecting rod is arranged on the side, facing the middle block body, of the first edge block body, the first connecting rod can slide along the first through groove and is detachably connected to the first clamping hole, and a second connecting rod is arranged on the side, facing the middle block body, of the second edge block body. The second connecting rod can slide along the second through groove and is detachably connected to the second clamping hole. According to the posterior lumbar fusion cage, through modular design, split linear imbedding and transverse combined expansion in an intervertebral space, the contact area between the posterior lumbar fusion cage and a vertebral end plate is increased, and adjacent blocks are tightly connected through a sliding groove structure with high feasibility.

Description

Technical Field

[0001] This invention relates to the technical field of devices for treating lumbar spine diseases, and more particularly to a posterior lumbar fusion device. Background Technology

[0002] In treating spinal disorders such as lumbar spondylolisthesis, instability, and disc herniation, the commonly used surgical approach in clinical practice is interbody fusion combined with pedicle screw / facet screw fixation. However, there is a certain margin of error during pedicle screw placement, which can sometimes inadvertently injure the spinal cord, nerve roots, blood vessels, and other surrounding soft tissues and organs. Even with intraoperative navigation or surgical robot-assisted screw placement, 100% accuracy cannot be achieved, and orthopedic robots are relatively expensive and not yet widely used in clinical practice. Furthermore, even with precise placement of pedicle screws / facet screws, there is still a certain probability of complications such as loosening and failure of internal fixation, screw breakage, rod breakage, stress shielding, metal allergy, and postoperative soft tissue pain.

[0003] Currently, lumbar interbody fusion is a mainstream surgical procedure for treating lumbar spondylolisthesis, instability, and disc herniation. There are various surgical approaches, including anterior ALIF, lateral OLIF, DLIF / XLIF, posterior TLIF, and PLIF, etc.

[0004] Anterior ALIF, lateral OLIF, and DLIF / XLIF, because the interbody fusion cage has a larger operating space to enter the intervertebral space, can complete the interbody fusion surgery with a single large fusion cage, thus avoiding many complications such as pedicle screw / facet screw loosening and failure, screw breakage, rod breakage, stress shielding, metal allergy, and postoperative soft tissue pain.

[0005] In the widely used posterior TLIF and PLIF procedures, the intervertebral fusion cage needs to pass through the safety triangle between the nerve root and the dural sac to enter the intervertebral space. The limited operating space prevents the use of larger intervertebral fusion cages. Currently used posterior fusion cages have a small contact area with the endplate and lack intervertebral fixation devices. If used alone without pedicle screws / facet screws for auxiliary fixation, complications such as vertebral endplate collapse and cage displacement / dislocation significantly increase. Chinese utility model patent No. 202022833817.0 discloses a multifunctional lumbar hinged fusion cage for TLIF, specifically a hinged design that increases the contact area between the fusion cage and the endplate, thus reducing vertebral endplate collapse to some extent. However, this hinged fusion cage is difficult to pass through the safety triangle in clinical practice. Even if it manages to pass through the safety triangle, it is difficult to complete hinge adjustment within the intervertebral space, failing to achieve the desired effect. Summary of the Invention

[0006] Therefore, a posterior lumbar fusion device is needed to solve the problem of difficult installation of existing fusion devices.

[0007] To achieve the above objectives, the inventors provide a posterior lumbar fusion device, comprising:

[0008] The central block has a first through slot and a second through slot on its symmetrical sides. A first snap-fit ​​hole is formed in the middle of the first through slot, and a second snap-fit ​​hole is formed in the middle of the second through slot.

[0009] The central block has a first edge block and a second edge block located on both sides of it. The first edge block has a first connecting rod on the side facing the central block. The first connecting rod can slide along the first through groove and is detachably connected to the first snap-fit ​​hole. The second edge block has a second connecting rod on the side facing the central block. The second connecting rod can slide along the second through groove and is detachably connected to the second snap-fit ​​hole, so that the central block is spaced apart from the first edge block and the second edge block.

[0010] Furthermore, both the upper and lower ends of the first and second through slots are provided with a first guide structure.

[0011] Furthermore, the first edge block is integrally formed with the first connecting rod, and the second edge block is integrally formed with the second connecting rod.

[0012] Furthermore, the side of the first edge block is provided with a third through groove running vertically through it, and a third snap-fit ​​hole is provided in the middle of the third through groove, and the first connecting rod is detachably connected to the third snap-fit ​​hole.

[0013] The second edge block has a fourth through groove running vertically through its side, and a fourth snap-fit ​​hole is provided in the middle of the fourth through groove. The second connecting rod can be detachably connected to the fourth snap-fit ​​hole.

[0014] Furthermore, the upper and lower ends of the third and fourth through slots are provided with second guide structures.

[0015] Furthermore, the detachable ends of the first connecting rod and the second connecting rod are symmetrically arranged along their length direction and are provided with elastic engaging portions at intervals.

[0016] Furthermore, the side of the first edge block away from the middle block is configured as an arc surface adapted to the edge of the cone, and the side of the second edge block away from the middle block is configured as an arc surface adapted to the edge of the cone.

[0017] Furthermore, the upper surfaces of the central block, the first edge block, and the second edge block are flush.

[0018] Furthermore, there are two or more central blocks, and adjacent central blocks are detachably spaced apart by a third connecting rod.

[0019] Furthermore, the central block, the first edge block, and the second edge block are all provided with inclined insertion holes, which are used for fixing inserts or screws.

[0020] Unlike existing technologies, the above-mentioned technical solution has the following advantages: The posterior lumbar fusion device uses a modular design to sequentially insert the first edge block, the second edge block, and the middle block into the intervertebral space in a straight line. The separate blocks are inserted in a straight line and then laterally combined and expanded within the intervertebral space to increase the contact area with the vertebral endplate. The adjacent blocks are tightly connected through a highly feasible sliding groove and snap-fit ​​hole structure. The device is significantly superior to existing fusion devices in terms of ease of insertion, postoperative stability, and complication control. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a posterior lumbar fusion device according to this embodiment;

[0022] Figure 2 This is a front view of a posterior lumbar fusion device according to this embodiment;

[0023] Figure 3 This is a three-dimensional view of the central block of a posterior lumbar fusion device according to this embodiment;

[0024] Figure 4 This is a top view of the middle block of a posterior lumbar fusion device according to this embodiment;

[0025] Figure 5 for Figure 4 Sectional view at point AA;

[0026] Figure 6 This is a schematic diagram showing that the first edge block and the first connecting rod are integrally formed in a posterior lumbar fusion device according to this embodiment.

[0027] Figure 7 This is a schematic diagram of the first edge block / second edge block of a posterior lumbar fusion device according to this embodiment;

[0028] Figure 8 This is a schematic diagram of a posterior lumbar fusion device used in the intervertebral space according to this embodiment;

[0029] Figure 9 A side view of a posterior lumbar fusion device according to this embodiment, showing a insert plate in the middle block;

[0030] Figure 10 This is a schematic diagram of the locking part of a posterior lumbar fusion device according to this embodiment.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Central block;

[0033] 11. First through slot;

[0034] 111. First card slot;

[0035] 12. Second through slot;

[0036] 121. Second snap-fit ​​hole;

[0037] 13. First guiding structure;

[0038] 2. First edge block;

[0039] 22. Second guiding structure;

[0040] 23. Third through slot;

[0041] 3. Second edge block;

[0042] 34. Fourth through slot;

[0043] 41. First connecting rod;

[0044] 411. Elastic opening and closing groove;

[0045] 412. Connecting part;

[0046] 42. Second connecting rod;

[0047] 5. Inserts or screws. Detailed Implementation

[0048] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0049] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0050] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0051] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0052] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0053] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0054] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0055] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0056] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0057] like Figure 1-5 This embodiment provides a posterior lumbar fusion device, comprising:

[0058] The central block 1 has a first through groove 11 and a second through groove 12 extending vertically through its symmetrical sides. The first through groove 11 has a first snap-fit ​​hole 111 in the middle, and the second through groove 12 has a second snap-fit ​​hole 121 in the middle.

[0059] The central block 1 is located on both sides of a first edge block 2 and a second edge block 3. The first edge block 2 is provided with a first connecting rod 41 on the side facing the central block 1. The first connecting rod 41 can slide along the first through groove 11 and is detachably connected to the first snap-fit ​​hole 111. The second edge block 3 is provided with a second connecting rod 42 on the side facing the central block 1. The second connecting rod 42 can slide along the second through groove 12 and is detachably connected to the second snap-fit ​​hole 121, so that the central block 1 is spaced apart from the first edge block 2 and the second edge block 3.

[0060] The shape of the central block 1 is similar to that of the TFC01 (12×10×22) and TFC01 (12×10×26) intervertebral fusion devices of Boyining Medical Company. In some embodiments, the shapes of the first edge block 2 and the second edge block 3 can also be designed to be similar to those of the TFC01 (12×10×22) and TFC01 (12×10×26) intervertebral fusion devices of Boyining Medical Company.

[0061] Unlike these fusion devices, the central block 1 of this application has a first through groove 11 and a second through groove 12 respectively on its two symmetrical sides, and a first snap-fit ​​hole 111 and a second snap-fit ​​hole 121 are respectively formed in the first through groove 11 and the second through groove 12. The first through groove 11 has openings on the upper and lower end faces of the central block 1, so that the first connecting rod 41 can slide into the first through groove 11 from the opening formed on the upper end face of the first through groove 11, or slide into the first through groove 11 from the opening formed on the lower end face of the first through groove 11. The second through groove 12 is symmetrically arranged with the first through groove 11. Since the first through groove 11 and the second through groove 12 on the middle block 1 are symmetrically arranged, both the first through groove 11 and the second through groove 12 can meet the connection requirements of the first connecting rod 41 and the second connecting rod 42 during the process of the middle block 1 being inserted from outside the intervertebral space and connected, or during the process of the middle block being connected to the second connecting rod 42 inside the intervertebral space, so that the doctor does not need to distinguish the orientation of the first through groove 11 and the second through groove 12 of the middle block 1. The first snap-fit ​​hole 111 is opened in the middle position of the first through groove 11, and the second snap-fit ​​hole 121 is opened in the middle position of the second through groove 12. It should be noted that the middle position of the first through groove 11 refers to a range close to the geometric center of the length dimension of the first through groove 11, and does not specifically refer to the length center of the first through groove 11. Similarly, the middle position of the second through groove 12 also refers to a range close to the geometric center of the length dimension of the second through groove 12, and does not specifically refer to the length center of the second through groove 12. The width and depth of the first through groove 11 and the second through groove 12 are the same, and the dimensions of the first snap-fit ​​hole 111 and the second snap-fit ​​hole 121 are also designed to be the same. In this way, when using the middle block 1, there is no need to distinguish its left and right sides, which is convenient for doctors to operate.

[0062] Specifically, the detachable connection means that the end of the first connecting rod 41 can be inserted into / out of the first snap-fit ​​hole 111. To ensure its connection strength, the end of the first connecting rod 41 used to connect to the first snap-fit ​​hole 111 has an expanded elastic part. After being inserted into the first snap-fit ​​hole 111, it can maintain its connection and is not easy to fall out. When it is necessary to disassemble the first connecting rod 41 from the first snap-fit ​​hole 111, it is only necessary to use a moderate force to deform the elastic part to make it fall out of the first snap-fit ​​hole 111. The connection relationship between the second connecting rod 42 and the second snap-fit ​​hole 121 is the same.

[0063] To maintain the relative positions of the central block 1, the first edge block 2, and the second edge block 3, the cross-sections of the first connecting rod 41 and the second connecting rod 42 can be designed as square structures. When the three are fixed together by the first connecting rod 41 and the second connecting rod 42, they will not rotate relative to each other, which is beneficial to the stability of the posterior lumbar fusion device. More preferably, when the cross-sections of the first connecting rod 41 and the second connecting rod 42 are rectangular, their length extension direction is the same as the length extension direction of the central block 1.

[0064] When using this posterior lumbar fusion device, the first edge block 2 is first inserted into the intervertebral space through the safety triangle area, and then moved a certain distance towards the edge of the vertebral body to make room for the middle block 1 to be inserted. Then, the middle block 1 is inserted into the intervertebral space through the safety triangle area, and the first connecting rod 41 slides along the first through groove 11 and is engaged in the first engagement hole 111 to form an "H" shaped combination. This combination is then moved a certain distance towards the edge of the vertebral body to make room for the second edge block 3 to be inserted. Finally, the second edge block 3 is inserted into the intervertebral space through the safety triangle area, and the second connecting rod 42 carried on the second edge block 3 slides along the second through groove 12 and is engaged in the second engagement hole 121. This completes the insertion of the posterior lumbar fusion device. The central block 1, the first edge block 2, and the second edge block 3 form a whole that has a large contact surface with the vertebral endplates above and below the intervertebral space. The adjacent blocks are tightly connected through a highly feasible sliding groove and snap-fit ​​hole structure, so that the posterior lumbar fusion device is stably fixed in the intervertebral space, avoiding vertebral endplate collapse, fusion device displacement / extrusion, and treatment of spinal diseases.

[0065] During the lumbar posterior fusion cage implantation surgery, both the vertebral body and the lumbar posterior fusion cage are operated under imaging guidance, which ensures the accuracy of the operation.

[0066] This posterior lumbar fusion device features a modular design that sequentially inserts the first edge block 2, the second edge block 3, and the central block 1 into the intervertebral space in a straight line. The separate blocks are inserted in a straight line and then laterally combined and expanded within the intervertebral space to increase the contact area. The highly feasible sliding groove structure allows adjacent blocks to be tightly connected. It is significantly superior to existing fusion devices in terms of ease of insertion, postoperative stability, and complication control, and is especially suitable for posterior intervertebral fusion surgeries such as TLIF.

[0067] like Figure 3 As shown, in some embodiments, both the upper and lower ends of the first through groove 11 and the second through groove 12 are provided with a first guide structure 13. Taking the first guide structure 13 on the first through groove 11 as an example, the first guide structure 13 can specifically be a symmetrically arranged inclined surface, arc-shaped chamfer, or tapered guide groove on both sides of the first through groove 11, so that the fusion device can be smoothly inserted into the intervertebral space, shortening the operation time. Of course, the effect of the first guide structure 13 on the second through groove 12 is the same. With the first guide structure 13 provided at both the upper and lower ends of the first through groove 11 and the second through groove 12, the first guide structure 13 can guide and guide the middle block 1 during the process of being inserted from outside the intervertebral space and connected to the first connecting rod 41, and during the process of the middle block 1 being connected to the second connecting rod 42 inside the intervertebral space, making it convenient for the doctor to operate the expansion connection of each module in the narrow intervertebral space.

[0068] like Figure 6 As shown, in some embodiments, the first edge block 2 is integrally formed with the first connecting rod 41, and the second edge block 3 is integrally formed with the second connecting rod 42. This has the advantage of reducing the number of parts in the posterior lumbar fusion device, reducing the connection steps between the first connecting rod 41 and the first edge block 2, and reducing the connection steps between the second edge block 3 and the second connecting rod 42. Especially in narrow intervertebral spaces, fewer connection steps can reduce surgical time and facilitate the surgeon's operation. Furthermore, the integrated design also enhances the structural strength.

[0069] like Figure 7 As shown, in some embodiments, the side of the first edge block 2 is provided with a third through groove 23 that runs vertically through the body, and a third snap-fit ​​hole (not shown in the figure, refer to the figure of the first snap-fit ​​hole) is provided in the middle of the third through groove 23. The first connecting rod 41 is detachably connected to the third snap-fit ​​hole.

[0070] The second edge block 3 has a fourth through groove 34 extending vertically through its side, and a fourth snap-fit ​​hole is provided in the middle of the fourth through groove 34. The second connecting rod 42 is detachably connected to the fourth snap-fit ​​hole (not shown in the figure, refer to the figure of the first snap-fit ​​hole).

[0071] The third through groove 23 and the fourth through groove 34 are similar in structure to the first through groove 11 and the second through groove 12 mentioned above. The third through groove 23 forms openings on the upper and lower end faces of the first edge block 2, so that the first connecting rod 41 can slide into the third through groove 23 through the opening formed on the upper end face of the third through groove 23, or slide into the third through groove 23 through the opening formed on the lower end face of the third through groove 23. The fourth through groove 34 forms openings on the upper and lower end faces of the first edge block 2, so that the second connecting rod 42 can slide into the fourth through groove 34 through the opening formed on the upper end face of the fourth through groove 34, or slide into the fourth through groove 34 through the opening formed on the lower end face of the fourth through groove 34.

[0072] In this embodiment, the first connecting rod 41 and the first edge block 2 are designed separately, and the second connecting rod 42 and the second edge block 3 are designed separately, which can improve the compatibility of each part. For example, the first edge block and the second edge block of different specifications can be selected, or the first connecting rod 41 and the connecting rod of different lengths can be used together to make the posterior lumbar fusion device have a higher compatibility.

[0073] like Figure 7As shown, in some embodiments, the upper and lower ends of the third through groove 23 and the fourth through groove 34 are provided with second guide structures 22. Taking the second guide structure 22 on the third through groove 23 as an example, the second guide structure 22 can specifically be a symmetrically arranged inclined surface, arc-shaped chamfer, or tapered guide groove on both sides of the third through groove 23, so that the fusion device can be smoothly inserted into the intervertebral space, shortening the operation time. Of course, the first guide structure 13 on the fourth through groove 34 has the same effect. With the second guide structure 22 provided at both the upper and lower ends of the third through groove 23 and the fourth through groove 34, the second guide structure 22 can guide and guide the first connecting rod 41 from outside the intervertebral space into the first edge block 2 and the second edge block 3 from outside the intervertebral space into the second connecting rod 42 in both processes, making it convenient for doctors to operate the expansion connection of each module in the narrow intervertebral space.

[0074] In this embodiment, the first edge block 2 is first inserted into the intervertebral space through the safety triangle area, and then moved a certain distance towards the edge of the vertebral body to create space for the first connecting rod 41 to be embedded. The first connecting rod 41 is then slid into the third locking hole along the third through groove 23, forming a "T"-shaped combination, and moved towards the edge of the vertebral body to create space for the middle block 1 to be embedded. The middle block 1 is then inserted into the intervertebral space through the safety triangle area, allowing the first connecting rod 41 to slide along the first through groove 11 and engage in the first locking hole 111, forming... The assembly is arranged in an "H" shape, and then moved further towards the edge of the vertebral body to create space for the second connecting rod 42 to be inserted. The second connecting rod 42 is slid into the second locking hole 121 along the second through groove 12, and the entire assembly is moved towards the edge of the vertebral body to a space where the second edge block 3 can be inserted. Finally, the second edge block 3 is placed into the intervertebral space through the safety triangle, and the second connecting rod 42 slides along the fourth through groove 34 and locks into the fourth locking hole. This completes the insertion of the posterior lumbar fusion device. The central block 1, the first edge block 2, and the second edge block 3 form a whole with a large contact surface with the vertebral endplates above and below the intervertebral space. The adjacent blocks are tightly connected through a highly feasible sliding groove and locking hole structure, so that the posterior lumbar fusion device is stably fixed in the intervertebral space, avoiding vertebral endplate collapse, fusion device displacement / extrusion, and treatment of spinal diseases.

[0075] like Figure 6As shown, in some embodiments, the detachable ends of the first connecting rod 41 and the second connecting rod 42 are each provided with an elastic opening groove 411 extending along its length. On both sides of the elastic opening groove 411, there are symmetrically arranged and spaced-apart engaging portions 412 along its length. The elastic opening groove 411 is centrally located at the end of the first connecting rod 41. When the first connecting rod 41 is inserted into the first engaging hole 111, the two sides of the elastic opening groove 411 are squeezed by the hole wall of the first engaging hole 111, causing the elastic opening groove 411 to close inwards. After the elastic opening groove 411 closes, the engaging portions 412 engage with the first engaging hole 111 to achieve fixation. In some embodiments, the middle part of the central block 1 is open, and the first locking hole 111 communicates with the middle part. When the first connecting rod 41 is inserted into the first locking hole 111, the gap of the locking part is adapted to the wall thickness of the first locking hole 111. Since multiple locking parts 412 are provided at intervals on the first connecting rod 41, the doctor can adjust the insertion depth of the first connecting rod 41 to achieve step-by-step adjustment. When the locking part 412 slides into the locking hole, there will be a noticeable step-like feeling and a crisp click, indicating that it has been locked in place. The locking part 412 can prevent the first connecting rod 41 from dislodging when there is no external force, further enhancing the stability of the structure. Taking the cross-section of the first connecting rod as a rectangle as an example, the elastic tension groove 411 is opened in the middle of the long side of its cross-section. The structure of the elastic tension groove 411 of the second connecting rod 42 is similar to the structure of the elastic tension groove 411 of the first connecting rod 41, and will not be described again here.

[0076] like Figure 10 As shown, in some embodiments, the detachable ends of the first connecting rod 41 and the second connecting rod 42 are symmetrically arranged along their length direction and are provided with elastic engaging portions 412 at intervals. Taking an embodiment where the cross-section of the first connecting rod is rectangular as an example, the elastic engaging portion 412 is provided on the long side of its cross-section, and the engaging portion deforms when pushed inward during the connection process.

[0077] like Figure 2 , Figure 8 As shown, in some embodiments, the side of the first edge block 2 away from the central block 1 is configured as an arc surface adapted to the edge of the vertebral body, and the side of the second edge block 3 away from the central block 1 is configured as an arc surface adapted to the edge of the vertebral body. The arc surfaces of the first edge block 2 and the second edge block 3 can perfectly cover the edge of the vertebral body, and the streamlined arc surfaces also help to eliminate stress peaks.

[0078] like Figure 2As shown, in some embodiments, the upper surfaces of the central block 1, the first edge block 2, and the second edge block 3 are flush. When the central block 1, the first edge block 2, and the second edge block 3 are assembled, their upper surfaces form a plane. Even if the posterior lumbar fusion device shifts within the intervertebral space, the overall posterior lumbar fusion device will not detach from the intervertebral space, and the upper end of the plane will not cause stress concentration on the posterior aspect of the vertebral body, resulting in higher safety.

[0079] In some embodiments, there are two or more central blocks 1, with adjacent central blocks 1 detachably spaced apart by a third connecting rod. For patients with wider vertebral bodies, the number of central blocks 1 can be increased to enhance the fusion strength of the posterior lumbar fusion device for the upper and lower vertebral bodies. Multiple central blocks 1 are still modularly designed and detachably spaced apart by the third connecting rod. The size of each central block 1 can be controlled within a reasonable range that allows passage through a safety triangle, facilitating the surgeon's selection of the number of central blocks 1 during surgery based on the actual situation. The structure of the third connecting rod is similar to that of the first connecting rod 41 or the second connecting rod 42 described above, and will not be repeated here.

[0080] In some embodiments, the central block 1, the first edge block 2, and the second edge block 3 are all provided with inclined insertion holes for fixing inserts or screws 5. After the posterior lumbar fusion cage is assembled and in place, to further prevent the posterior lumbar fusion cage from shifting within the intervertebral space, inserts or screws can be embedded in the insertion holes to further secure the central block 1, the first edge block 2, and the second edge block 3 to the endplates of the upper and / or lower vertebral bodies, further enhancing the fusion strength of the posterior lumbar fusion cage. Figure 9 The diagram shown is a schematic of the structure with inserts on the central block 1.

[0081] The above description is mainly based on the application of the posterior lumbar fusion device of this application in TLIF posterior intervertebral fusion surgery. Of course, the posterior lumbar fusion device of this application can also be used in anterior or lateral intervertebral fusion surgery. Since the insertion channel is larger in anterior and lateral intervertebral fusion surgery, the central block 1, the first edge block 2, and the second edge block 3 can be combined into a whole before being inserted into the intervertebral space. Alternatively, by designing insertion holes in front of or to the side of each block, the whole can be fixed to the intervertebral space with inserts or screws.

[0082] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A posterior lumbar fusion device, characterized in that, include: The central block has a first through slot and a second through slot on its symmetrical sides. The first through slot has a first snap-fit ​​hole in the middle, and the second through slot has a second snap-fit ​​hole in the middle. The central block has a first edge block and a second edge block located on both sides of it. The first edge block has a first connecting rod on the side facing the central block. The first connecting rod can slide along the first through groove and is detachably connected to the first snap-fit ​​hole. The second edge block has a second connecting rod on the side facing the central block. The second connecting rod can slide along the second through groove and is detachably connected to the second snap-fit ​​hole, so that the central block is spaced apart from the first edge block and the second edge block.

2. The posterior lumbar fusion device according to claim 1, characterized in that: Both the upper and lower ends of the first and second through slots are provided with a first guide structure.

3. The posterior lumbar fusion device according to claim 1, characterized in that: The first edge block is integrally formed with the first connecting rod, and the second edge block is integrally formed with the second connecting rod.

4. The posterior lumbar fusion device according to claim 1, characterized in that: The first edge block has a third through groove running vertically through its side, and a third snap-fit ​​hole is provided in the middle of the third through groove. The first connecting rod can be detachably connected to the third snap-fit ​​hole. The second edge block has a fourth through groove running vertically through its side, and a fourth snap-fit ​​hole is provided in the middle of the fourth through groove. The second connecting rod can be detachably connected to the fourth snap-fit ​​hole.

5. The posterior lumbar fusion device according to claim 4, characterized in that: The upper and lower ends of the third and fourth through slots are each provided with a second guide structure.

6. The posterior lumbar fusion device according to claim 1 or 4, characterized in that: The detachable ends of the first connecting rod and the second connecting rod are symmetrically arranged along their length and are provided with elastic engaging portions at intervals.

7. The posterior lumbar fusion device according to claim 1, characterized in that: The side of the first edge block away from the middle block is configured as an arc surface adapted to the edge of the cone, and the side of the second edge block away from the middle block is configured as an arc surface adapted to the edge of the cone.

8. The posterior lumbar fusion device according to claim 1, characterized in that: The upper surfaces of the central block, the first edge block, and the second edge block are flush.

9. The posterior lumbar fusion device according to claim 1, characterized in that: There are two or more central blocks, and adjacent central blocks are detachably separated by a third connecting rod.

10. The posterior lumbar fusion device according to claim 1, characterized in that: The central block, the first edge block, and the second edge block are all provided with inclined insertion holes, which are used for fixing inserts or screws.

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