Expandable multi-head structure assembly fixed in spine

Abstract

The invention provides an extensible multi-head structure assembly fixed in a spine, and relates to the field of medical instruments, the extensible multi-head structure assembly comprises a base body, the base body is provided with an assembling through hole and an expanding groove, the assembling through hole is used for positioning a cap structure, and the hole wall of the assembling through hole is provided with a first concave-convex part used for being clamped and matched with the cap structure. The expanding grooves are used for positioning the fixing rods. Due to the design of the structural component, the operation steps of internal fixation of the spine can be simplified, the operation difficulty can be reduced, the use flexibility can be improved, the overall structure compactness can be improved, the overall size can be reduced, the incisura can be reduced, soft tissue irritation can be reduced, and the probability of postoperative complications can be reduced.

Description

Technical Field

[0001] The invention relates to the field of medical devices, and in particular to an expandable multi-head structural component for spinal internal fixation. Background Art

[0002] Pedicle screws, lamina hooks, and spinal bands are widely used in spinal internal fixation surgery. On the one hand, they form a mechanically stable and semi-stable connection with the anatomical structure of the spine through various means, and on the other hand, they establish a stable or semi-stable connection with the rigid internal fixation rod through the cap structure. They are the general way of spinal internal fixation. However, when the internal fixation rod is not long enough, or the distance between the internal fixation rods needs to be changed due to changes in the size of the vertebral body, or for the purpose of enhancing mechanical strength, or for a certain surgical procedure that requires multiple rod fixation, it is necessary to add new anchor points for the fixation rods to the original fixation structure.

[0003] The inventors found in their research that the existing method of adding new anchor points has at least the following disadvantages:

[0004] The surgeon has high requirements for preoperative planning ability and the operation is difficult. The operation is complicated and inflexible to use. The anatomical space is large and it is difficult to meet the needs of the operation. Summary of the invention

[0005] The objects of the present invention include, for example, providing an expandable multi-head structure component for spinal internal fixation, which can simplify the operation steps, reduce the operation difficulty, improve the flexibility of use, and can also improve the compactness of the overall structure, reduce the overall volume, reduce the notch, reduce soft tissue irritation, and reduce the chance of postoperative complications.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present invention provides an expandable multi-head structural assembly for spinal internal fixation, comprising:

[0008] A base body is provided with an assembly through hole and an expansion groove, the assembly through hole is used to position the cap structure, and a first concave-convex portion for snap-fitting with the cap structure is provided on the hole wall of the assembly through hole; the expansion groove is used to position the fixing rod.

[0009] In an optional embodiment, the number of the expansion grooves is set to be multiple.

[0010] Based on the above solution, each expansion groove can fix a fixing rod. By reasonably designing the number of expansion grooves, multiple fixing rods can be positioned, which is flexible to use and has a wide range of uses.

[0011] In an optional embodiment, the plurality of expansion grooves are distributed on the same side of the assembly through hole or on two opposite sides of the assembly through hole.

[0012] Based on the above solution, the distribution of the expansion groove is different, and the fixing rod can be distributed on both sides or the same side of the assembly through hole. It is flexible to use and has a wide range of uses to meet the needs of different scenarios.

[0013] In an optional embodiment, a positioning groove for engaging with the fixing rod is provided on the hole wall of the assembly through hole, and a spacing is provided between the positioning groove and the first concave-convex portion in the circumferential direction of the assembly through hole.

[0014] Based on the above solution, after the cap structure is installed in the assembly through hole, the clamping groove on the cap structure for clamping the fixing rod is connected with the positioning groove, the fixing rod can be clamped in the clamping groove and the positioning groove at the same time, and the position of the fixing rod is firm and reliable.

[0015] In an optional embodiment, the notch of the positioning groove and the notch of the expansion groove are located on the same side of the base.

[0016] Based on the above scheme, the cap structure is placed into the assembly through hole from one end of the assembly through hole. The notch of the clamping groove formed by the cap structure and the notch of the positioning groove are located on the same side. The fixing rod can be directly placed into the positioning groove from the notch of the clamping groove, which is convenient for the installation and positioning of the fixing rod.

[0017] In an optional embodiment, the notch of the positioning groove and the notch of the expansion groove are located on two opposite sides of the base.

[0018] Based on the above scheme, the cap structure is placed into the assembly through hole from one end of the assembly through hole, the notch of the clamping groove formed by the cap structure and the notch of the positioning groove are located on opposite sides of the base, and the fixing rod is assembled by inserting it into the socket formed by the clamping groove and the positioning groove. The height of the cap structure extending out of the base corresponding to the notch of the expansion groove is reduced.

[0019] In an optional embodiment, the assembly through hole has a first wall and a second wall that are connected and arranged at an angle, the first concave-convex portion is arranged on the first wall, and the positioning groove is arranged on the second wall.

[0020] Based on the above scheme, the clamping groove of the cap structure is connected to the positioning groove, and the clamping arm of the cap structure can move adaptively in the groove width direction of the clamping groove. When the cap structure is installed, the clamping arm is provided with a second concave-convex portion corresponding to the first concave-convex portion. When the second concave-convex portion contacts the first concave-convex portion, the clamping arm can move inward to avoid interference between the second concave-convex portion and the first concave-convex portion, which is convenient for installation. When the second concave-convex portion moves to fully engage with the first concave-convex portion, the clamping arm expands outward to achieve a tight engagement between the second concave-convex portion and the first concave-convex portion, which is convenient for assembly. At the same time, after the cap structure is installed, a fixing screw is provided in the clamping groove to lock the fixing rod. Under the action of the fixing screw, the clamping arm can appropriately expand outward to improve the firmness of the combination of the second concave-convex portion and the first concave-convex portion.

[0021] In an optional embodiment, the first concave-convex portion is configured as a protrusion, and a surface of the protrusion away from the hole wall of the assembly through hole is provided with a guiding inclined surface.

[0022] Based on the above solution, the structure of the first concave-convex portion is simple and easy to process, and the setting of the guiding inclined surface facilitates the assembly of the cap structure and the base.

[0023] In an optional embodiment, the number of the first concave-convex portions is plural and they are arranged at intervals in the circumferential direction of the assembly through hole.

[0024] Based on the above solution, the plurality of first concave-convex parts cooperate with the cap structure to improve firmness.

[0025] In an optional embodiment, thread grooves are provided on two opposite groove side walls of the expansion groove.

[0026] Based on the above solution, the fixing rod can be pressed tightly into the expanded groove by screwing the fixing screw into the threaded groove.

[0027] The beneficial effects of the embodiments of the present invention include, for example:

[0028] In summary, the spinal internal fixation expandable multi-head structure assembly provided by the present embodiment can place a cap structure in the assembly through hole, a fixing rod can be placed in the cap structure, and a fixing screw can be set in the clamping groove of the cap structure, and the fixing rod can be fixed in the clamping groove by the fixing screw. At the same time, a fixing rod can be placed in the expansion groove, and the fixing rod can be fixed by a fixing screw connected to the expansion groove. Moreover, the number of expansion grooves can be set as needed, so that two or more fixing rods can be fixed, and the number of fixing rods can be expanded, which is suitable for different surgical scenes, and is flexible to use and has a wide range of uses. Because when the cap structure cooperates with the assembly through hole, the second concave-convex part on the cap structure can be engaged with the first concave-convex part on the hole wall of the assembly through hole to achieve the axial limit of the cap structure and the base, that is, the first concave-convex part and the second concave-convex part cooperate to form a mortise and tenon clamping structure, so as to achieve the fixed connection between the cap structure and the base, so that the freedom of the cap structure in the axial direction of the assembly through hole is limited, and the cap structure will not fall out of the assembly through hole, thereby ensuring that the position of the fixing rod on the cap structure is firm and reliable. The mortise and tenon clamping structure is located in the assembly through hole, does not occupy external space, and will not increase the volume of the overall structure. At the same time, there is no need to set a stud in the clamping groove of the cap structure for fixing the cap structure and extending out of the notch of the clamping groove, and the nut screwed on the outside of the stud is also omitted, which simplifies the structure and reduces the axial height of the overall structure in the assembly through hole, effectively reduces the notch, reduces soft tissue irritation, and reduces the incidence of postoperative pain and discomfort caused by internal fixation surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of an expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0031] Figure 2 For the corresponding Figure 1 A cross-sectional schematic diagram of

[0032] Figure 3 A schematic diagram of a deformation of an expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0033] Figure 4 For the corresponding Figure 3 A cross-sectional schematic diagram of

[0034] Figure 5This is a first application schematic diagram of the expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0035] Figure 6 For the corresponding Figure 5 A cross-sectional schematic diagram of

[0036] Figure 7 A second application schematic diagram of the expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0037] Figure 8 A third application schematic diagram of the expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0038] Fig. 9 For the corresponding Figure 8 A cross-sectional schematic diagram of

[0039] Fig.10 A fourth application schematic diagram of the expandable multi-head structural assembly for spinal internal fixation according to an embodiment of the present application;

[0040] Fig.11 For the corresponding Fig.10 Schematic cross-sectional view of .

[0041] icon:

[0042] 100-base; 110-assembly through hole; 111-first side wall; 112-second side wall; 113-third side wall; 114-fourth side wall; 115-first port; 116-second port; 120-expansion groove; 121-second threaded groove; 130-first concave-convex portion; 131-guide slope; 140-positioning groove; 200-cap structure; 210-bottom plate; 211-fixing through hole; 220-clamping arm; 230-clamping groove; 231-first threaded groove; 240-second concave-convex portion; 300-fixing piece; 400-pressing block; 500-fixing rod; 600-first fixing screw; 700-second fixing screw. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0047] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0048] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0049] Example

[0050] Please refer to Figure 1-Figure 4 In this embodiment, the expandable multi-head structure assembly for spinal internal fixation includes a base 100, which is provided with an assembly through hole 110 and an expansion groove 120. The assembly through hole 110 is used to position the cap structure 200, and the hole wall of the assembly through hole 110 is provided with a first concave-convex portion 130 for engaging with the cap structure 200. The expansion groove 120 is used to position the fixing rod 500.

[0051] Please combine Figure 5-Figure 11 It should be noted that the expandable multi-head structure assembly for spinal internal fixation provided in this embodiment can be used in conjunction with the cap structure 200, the fixing member 300, the pressing block 400, the fixing rod 500, the first fixing screw 600 and the second fixing screw 700.

[0052] Please combine Figure 5 and Figure 6, wherein the cap structure 200 includes an integrally designed bottom plate 210 and two clamping arms 220, the two clamping arms 220 are located on opposite sides of the bottom plate 210, the bottom plate 210 and the two clamping arms 220 cooperate to define a clamping groove 230, the inner side surface of the clamping arm 220 is the groove side wall of the clamping groove 230, and the inner wall surface of each clamping arm 220 is provided with a first threaded groove 231, and the first threaded groove 231 on the two clamping arms 220 can be screwed with the first fixing screw 600. A fixing through hole 211 is provided on the bottom plate 210, and the fixing through hole 211 can also be understood as a groove bottom wall setting that passes through the clamping groove 230. The fixing member 300 can be a lamina hook or a pedicle screw. In this embodiment, the fixing member 300 is described as a pedicle screw as an example. The pressing block 400 is installed in the clamping groove 230, and the pressing block 400 cooperates with the spherical head of the pedicle screw, so that the pedicle screw can be adjusted 360 degrees before being locked. The fixing rod 500 is placed in the clamping groove 230 and is located above the pressing block 400. The first fixing screw 600 cooperates with the first threaded grooves 231 on the two clamp arms 220 and is screwed into the clamping groove 230. The fixing rod 500, the pressing block 400 and the pedicle screw are locked by the first fixing screw 600.

[0053] At the same time, a second concave-convex portion 240 is provided on the outer side surface of at least one of the two clamping arms 220 of the cap structure 200, which can be engaged with the first concave-convex portion 130 on the hole wall of the assembly through hole 110 to form a mortise and tenon joint structure.

[0054] As described above, the use of the expandable multi-head structural assembly for spinal internal fixation provided in this embodiment includes, for example:

[0055] Please combine Figure 8-Figure 11 , insert the cap structure 200 into the assembly through hole 110 with the base plate 210 as the front end, insert the pedicle screw into the fixing through hole 211, install the pressing block 400 in the clamping groove 230, place a fixing rod 500 in the clamping groove 230 and abut against the pressing block 400, after adjusting the angle of the conical pedicle screw, screw the first fixing screw 600 into the clamping groove 230, and use the first fixing screw 600 to lock the fixing rod 500, the pressing block 400 and the pedicle screw. At this time, the fixing of a fixing rod 500 is completed. At the same time, a fixing rod 500 can be placed in the expansion groove 120, and the fixing rod 500 can be fixed by a second fixing screw 700 connected to the expansion groove 120. It should be understood that the number of expansion grooves 120 on the base 100 can be set as needed, so that two or more fixing rods 500 can be fixed, so as to achieve the expansion of the number of fixing rods 500, adapt to different surgical scenes, and be flexible in use and have a wide range of uses.

[0056] When the cap structure 200 cooperates with the assembly through hole 110, the second concave-convex portion 240 on the clamp arm 220 can be engaged with the first concave-convex portion 130 on the hole wall of the assembly through hole 110, thereby realizing the axial limitation of the cap structure 200 and the base 100 in the assembly through hole 110, that is, the first concave-convex portion 130 and the second concave-convex portion 240 cooperate to form a mortise and tenon engaging structure, thereby realizing the fixed connection between the cap structure 200 and the base 100, so that the axial freedom of the cap structure 200 in the assembly through hole 110 is limited, and the cap structure 200 will not fall out of the assembly through hole 110, thereby ensuring that the position of the fixing rod 500 on the cap structure 200 is firm and reliable. The mortise and tenon clamping structure is located in the assembly through hole 110, does not occupy external space, and will not increase the volume of the overall structure. At the same time, there is no need to set a stud in the clamping groove 230 of the cap structure 200 for fixing the cap structure 200 and extending out of the notch of the clamping groove 230, and the nut screwed on the outside of the stud is also omitted, thereby simplifying the structure and reducing the axial height of the overall structure in the assembly through hole 110, effectively reducing the notch, less soft tissue irritation, and reducing the incidence of postoperative pain and discomfort caused by internal fixation surgery.

[0057] The following embodiments illustrate the details of the expandable multi-head structural assembly for spinal internal fixation provided by the present application by way of examples.

[0058] Please combine Figure 5 , Figure 8 and Fig.10 It should be understood that the number of expansion grooves 120 on the base 100 can be one or more, and the number of expansion grooves 120 is consistent with the number of expanded fixing rods 500, that is, a fixing rod 500 can be positioned in each expansion groove 120, and multiple expansion grooves 120 can fix multiple fixing rods 500. It can be selected according to needs and is flexible to use.

[0059] Moreover, when there are multiple expansion grooves 120, that is, when the number of expansion grooves 120 is two or more, the multiple expansion grooves 120 can be located on the same side of the assembly through hole 110, or, the multiple expansion grooves 120 are distributed on two opposite sides of the assembly through hole 110.

[0060] In order to fix the fixing rod 500 in the expansion groove 120, a second threaded groove 121 can be set on the side wall of the expansion groove 120, and the second fixing screw 700 is screwed into the second threaded groove 121 to press the fixing rod 500 into the expansion groove 120. The installation method is simple and reliable, and the operation is convenient.

[0061] Please combine Figure 1 and Figure 2In this embodiment, optionally, the assembly through hole 110 has a first port 115 and a second port 116 that are opposite to each other in the axial direction thereof, the first port 115 and the notch of the expansion groove 120 are located on the same side, the cap structure 200 is placed into the assembly through hole 110 from the first port 115, and the first concave-convex portion 130 and the second concave-convex portion 240 are engaged to prevent the cap structure 200 from escaping from the second port 116. At the same time, the assembly through hole 110 has a first side wall 111 and a second side wall 112 arranged in the first direction, and a third side wall 113 and a fourth side wall 114 arranged in the second direction, and the first direction and the second direction are perpendicular. The first side wall 111, the third side wall 113, the second side wall 112 and the fourth side wall 114 are connected end to end in sequence. The assembly through hole 110 and the expansion groove 120 are arranged in the first direction. A first concave-convex portion 130 is provided on the first side wall 111. The first concave-convex portion 130 can be a protrusion. A guide slope 131 can be provided on the surface of the first concave-convex portion 130 away from the first side wall 111. The guide slope 131 is used to contact the clamp arm 220 when the cap structure 200 is pulled out of the assembly through hole 110 from the first port 115 to the second port 116, so that the two clamp arms 220 have a tendency to approach each other, thereby allowing the first concave-convex portion 130 and the second concave-convex portion 240 to be smoothly separated, which is convenient for disassembly.

[0062] It should be understood that in other embodiments, the first concave-convex portion 130 may also be provided on the second side wall 112, or the number of the first concave-convex portions 130 on the first side wall 111 and the second side wall 112 may be two or more. In this way, by providing a plurality of first concave-convex portions 130, and the plurality of first concave-convex portions 130 are arranged at intervals in the circumferential direction of the assembly through hole 110, a plurality of second concave-convex portions 240 are correspondingly provided on the clamping arm 220 of the cap structure 200. By snap-fitting the plurality of first concave-convex portions 130 and the plurality of second concave-convex portions 240, a plurality of riveted snap-fit ​​structures can be formed, thereby improving the firmness of the combination.

[0063] Please combine Figure 1 or Figure 3At the same time, positioning grooves 140 are provided on the third side wall 113 and the fourth side wall 114. The two positioning grooves 140 are symmetrically arranged, and the fixing rod 500 passes through the two positioning grooves 140 at the same time. That is to say, after the cap structure 200 is inserted into the assembly through hole 110, the two positioning grooves 140 are respectively connected to the two sides of the clamping groove 230, and the fixing rod 500 can pass through the clamping groove 230 and the two positioning grooves 140 at the same time to achieve installation and positioning. When the cap structure 200 is matched with the assembly through hole 110, the width direction of the clamping groove 230 is the first direction, and the two clamp arms 220 are arranged in the first direction. The two clamp arms 220 are in contact with the first side wall 111 and the second side wall 112 respectively, and the clamp arms 220 are restricted from expanding outward by the first side wall 111 and the second side wall 112. When the first fixing screw 600 is screwed into the clamping groove 230, the first fixing screw 600 is tightly matched with the clamping groove 230 and will not loosen, and the fixing effect is good. At the same time, since the first convex-concave portion 130 is arranged on the first side wall 111 or the second side wall 112, after the second convex-concave portion 240 on the clamping arm 220 is engaged with the first convex-concave portion 130, under the action of the first fixing screw 600, the two clamping arms 220 can be tightly attached to the first side wall 111 and the second side wall 112, so that the first convex-concave portion 130 and the second convex-concave portion 240 are more firmly engaged, and the cap structure 200 will not fall out of the assembly through hole 110. The first fixing screw 600 not only realizes the positioning of the fixing rod 500, but also can improve the firmness of the engagement between the cap structure 200 and the base 100.

[0064] Please combine Figure 1 and Figure 2 In one embodiment, optionally, the notch of the positioning groove 140 and the notch of the expansion groove 120 are located on opposite sides of the base 100. The cap structure 200 is placed into the assembly through hole 110 from the first port 115 of the assembly through hole 110, and the notch of the clamping groove 230 formed by the cap structure 200 and the notch of the positioning groove 140 are located on opposite sides of the base 100. The fixing rod 500 is assembled by inserting into the insertion hole formed by the clamping groove 230 and the positioning groove 140. The height of the cap structure 200 extending out of the base 100 corresponding to the notch of the expansion groove 120 is reduced, thereby reducing the height of the overall structure.

[0065] Please combine Figure 3 and Figure 4In another embodiment, optionally, the notch of the positioning groove 140 and the notch of the expansion groove 120 are located on the same side of the base 100, and the cap structure 200 is placed into the assembly through hole 110 from the first port 115 of the assembly through hole 110. The notch of the clamping groove 230 formed by the cap structure 200 and the notch of the positioning groove 140 are located on the same side, and the fixing rod 500 can be directly placed into the positioning groove 140 from the notch of the clamping groove 230, which is convenient for the installation and positioning of the fixing rod 500.

[0066] In addition, the first concavoconvex part 130 can be set as a protrusion, and the second concavoconvex part 240 can be set as a groove matching the protrusion. Obviously, in other embodiments, the first concavoconvex part 130 can also be a groove, and correspondingly, the second concavoconvex part 240 is set as a protrusion matching the groove.

[0067] The present embodiment provides an expandable multi-head structural component for spinal internal fixation, in which the cap structure 200 and the base 100 are connected and fixed by an internal hidden mortise and tenon joint structure, without occupying the external space of the base 100 and without increasing the volume of the overall structure. At the same time, there is no need to provide a stud in the clamping groove 230 of the cap structure 200 for fixing the cap structure 200 and extending out of the notch of the clamping groove 230, and the nut screwed on the outside of the stud is also omitted, thereby simplifying the structure and reducing the axial height of the overall structure in the assembly through hole 110, effectively reducing the notch, resulting in less soft tissue irritation, and reducing the incidence of postoperative pain and discomfort caused by internal fixation surgery.

[0068] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An expandable multi-head structural assembly for spinal internal fixation, characterized in that: include: A base body (100) is provided with an assembly through hole (110) and an expansion groove (120), the assembly through hole (110) is used to position a cap structure (200), and a first concave-convex portion (130) is provided on the hole wall of the assembly through hole (110) for snap-fitting with the cap structure (200); the expansion groove (120) is used to position a fixing rod (500).

2. The expandable multi-head structural assembly for spinal internal fixation according to claim 1, characterized in that: The number of the expansion grooves (120) is set to be multiple.

3. The expandable multi-head structural assembly for spinal internal fixation according to claim 2, characterized in that: The plurality of expansion grooves (120) are distributed on the same side of the assembly through hole (110) or on two opposite sides of the assembly through hole (110).

4. The expandable multi-head structural assembly for spinal internal fixation according to claim 1, characterized in that: A positioning groove (140) for engaging with a fixing rod (500) is provided on the hole wall of the assembly through hole (110), and a spacing is provided between the positioning groove (140) and the first concave-convex portion (130) in the circumferential direction of the assembly through hole (110).

5. The expandable multi-head structural assembly for spinal internal fixation according to claim 4, characterized in that: The notch of the positioning groove (140) and the notch of the expansion groove (120) are located on the same side of the base (100).

6. The expandable multi-head structural assembly for spinal internal fixation according to claim 4, characterized in that: The notch of the positioning groove (140) and the notch of the expansion groove (120) are located on two opposite sides of the base (100).

7. The expandable multi-head structural assembly for spinal internal fixation according to claim 4, characterized in that: The assembly through hole (110) comprises a first wall and a second wall which are connected and arranged at an angle, the first concave-convex portion (130) is arranged on the first wall, and the positioning groove (140) is arranged on the second wall.

8. The expandable multi-head structural assembly for spinal internal fixation according to claim 1, characterized in that: The first concavo-convex portion (130) is arranged as a protrusion, and a surface of the protrusion away from the hole wall of the assembly through hole (110) is provided with a guiding inclined surface (131).

9. The expandable multi-head structural assembly for spinal internal fixation according to claim 1, characterized in that: The first concave-convex portions (130) are multiple in number and are arranged at intervals in the circumferential direction of the assembly through hole (110).

10. The expandable multi-head structural assembly for spinal internal fixation according to claim 1, characterized in that: The two opposite groove side walls of the expansion groove (120) are both provided with thread grooves.

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