Anti-receding expansion type interbody fusion cage
By setting a limiting groove and a retaining ring groove on the inner wall of the intervertebral fusion device, the problems of increased ineffective size and rebound risk are solved, and the stability and reliability of the fusion device are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-03-31
AI Technical Summary
Existing interbody fusion devices have increased ineffective dimensions when in the open state and pose a risk of rebound, affecting treatment outcomes.
A limiting groove is set on the inner side wall of the tube, and the retaining ring is inserted into the groove. The end face of the pull rod is flush with the end face of the tube to prevent the pull rod from protruding. The retaining ring returns to its original shape in the groove to limit the rebound.
This reduces the ineffective dimensions after expansion, improves the stability of the fusion device, lowers the risk of rebound, and ensures treatment effectiveness.
Smart Images
Figure CN224056143U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of medical equipment technology, specifically to an anti-retrograde expansion interbody fusion device. Background Technology
[0002] The intervertebral space is the gap between two adjacent vertebrae; in lumbar intervertebral spaces, the tissue between them is the intervertebral disc. When the intervertebral disc deteriorates due to age or prolonged sitting and strain, it becomes deflated, and the distance between the two vertebrae decreases. When the intervertebral space narrows, the weakest part of the disc is more likely to protrude, compressing surrounding nerves and causing disc herniation. The usual treatment for disc herniation is to implant a fusion cage within the intervertebral space, combined with the implantation of autologous or allogeneic bone, to restore and maintain the height of the intervertebral space.
[0003] like Figure 10 , Figure 11 and Figure 12 As shown, the existing fusion device includes a tube body with a supporting expansion joint and a stabilizing expansion joint arranged axially along the tube body. A tie rod is installed inside the tube body, with a limiting block at one end of the tie rod, which abuts against one end of the tube body. The other end of the tie rod has a groove with an open retaining ring inside. The original form of the fusion device is a columnar structure. When a surgical tool is used to press against the other end of the tube body and the tie rod is pulled, the supporting and stabilizing expansion joints on the tube body expand, thereby supporting the vertebral bodies on both sides and restoring the intervertebral space to its original height. At the same time, the length of the tube body shortens until the retaining ring on the tie rod moves to the outside of the tube body. At this point, the retaining ring returns to its original shape under the action of its own elastic restoring force, and its outer diameter increases, thereby pressing against the end face of the other end of the tube body to prevent the tube body of the fusion device from springing back.
[0004] While this structure can prevent springback, it still has the following problems:
[0005] First, when the fusion device is in the expanded state, part of the tie rod protrudes outside the tube. Within the limited support space, this part cannot play a supporting role, increasing the ineffective size after expansion.
[0006] Secondly, before the fusion device is opened, the retaining ring on the tie rod remains in a contracted state. If the retaining ring remains contracted for an extended period, it may not return to its original shape when the device is opened, thus losing its limiting and stopping function. Furthermore, even if the retaining ring partially returns to its original shape, although the fusion device does not rebound during the surgery, the limiting size of the retaining ring is smaller than the designed limiting size. This means the fusion device may still rebound after implantation, potentially leading to vertebral collapse, surgical failure, and in severe cases, not only failing to provide treatment but also worsening the condition. Utility Model Content
[0007] To address the aforementioned issues, this application provides an anti-retraction expansion interbody fusion device that not only reduces the ineffective size of the device after expansion but also operates reliably and reduces the risk of rebound.
[0008] The technical solution adopted by this utility model to solve its technical problem is:
[0009] An anti-retraction expansion interbody fusion device includes a tube and a tie rod;
[0010] The pull rod includes a rod body and a limiting block, and the rod body is inserted into the tube body from one side;
[0011] A limiting groove is provided on the inner wall of the tube, and a retaining ring is provided in the limiting groove. A slot is provided on the rod. When the intervertebral fusion device is opened, the retaining ring is sleeved on the rod and locked into the slot.
[0012] Furthermore, when the interbody fusion device is opened, the end face of the rod is located inside the tube or flush with the end face of the tube.
[0013] Furthermore, a guide structure is provided at the end of the rod.
[0014] Furthermore, the guide structure is a conical or spherical structure.
[0015] Furthermore, the retaining ring described above has an opening.
[0016] Furthermore, when the retaining ring is in a free state, the outer diameter of the retaining ring is smaller than the diameter of the limiting groove, but larger than the inner diameter of the tube body.
[0017] Furthermore, the inner diameter of the retaining ring is less than or equal to the diameter of the groove portion of the rod.
[0018] Furthermore, the end of the tube is provided with a groove for accommodating the limiting block, and the cooperation between the groove and the limiting block can restrict the degree of freedom of the pull rod to rotate relative to the tube.
[0019] Furthermore, the groove extends through the tube body. When the limiting block is located within the groove, the end face of the limiting block is parallel to the end face of the tube body, and the limiting block and the tube body form a complete cylindrical surface.
[0020] Furthermore, the pipe body is provided with several supporting expansion joints and one stabilizing expansion joint along the axial direction, and the stabilizing expansion joint has supporting expansion joints on both sides.
[0021] The beneficial effects of this utility model are:
[0022] The anti-retraction expansion type interbody fusion device provided in this application embodiment has a limiting groove on the inner wall of the tube body, a retaining ring with an opening in the limiting groove, and a slot on the side wall of the tie rod. When the fusion device is expanded, the tie rod passes through the inner hole of the retaining ring, and the retaining ring is engaged in the slot. This effectively limits the expanded tube body between the limiting block of the tie rod and the retaining ring, thus keeping the fusion in a stable expanded state. Since the retaining ring is set inside the tube body, on the one hand, the tie rod does not need to protrude outside the tube body after expansion, so it does not increase the invalid size after expansion; on the other hand, the retaining ring is always in a free state before expansion, and the retaining ring will only deform when the tie rod passes through the retaining ring. Therefore, the retaining ring will not undergo plastic deformation. When the slot and the retaining ring are aligned, the retaining ring can quickly return to its original shape, thus reliably preventing rebound. Attached Figure Description
[0023] Figure 1 A three-dimensional structural diagram of an anti-retrograde expansion interbody fusion device provided in this application embodiment. Figure 1 ;
[0024] Figure 2 A three-dimensional structural diagram of an anti-retrograde expansion interbody fusion device provided in this application embodiment. Figure 2 ;
[0025] Figure 3 for Figure 2 A magnified structural diagram of part A in the middle;
[0026] Figure 4 A front view of an anti-retraction expansion interbody fusion device provided in an embodiment of this application;
[0027] Figure 5 for Figure 4 AA section view in the middle;
[0028] Figure 6 for Figure 5 A magnified structural diagram of section C;
[0029] Figure 7 for Figure 5 A magnified structural diagram of part B in the middle section;
[0030] Figure 8 for Figure 4 BB section view in the middle;
[0031] Figure 9 This is a schematic diagram of the structure of an anti-retraction expansion interbody fusion device in the expanded state, provided in an embodiment of this application.
[0032] Figure 10 This is a schematic diagram of the structure of a traditional interbody fusion device;
[0033] Figure 11 This is a schematic diagram of a traditional interbody fusion cage in its expanded state.
[0034] Figure 12 for Figure 11 A magnified structural diagram of part D in the middle.
[0035] In the diagram: 1. Pipe body; 11. Supporting expansion joint; 12. Stabilizing expansion joint; 13. Limiting groove;
[0036] 2. Pull rod; 21. Rod body; 211. Slot; 22. Limiting block; 23. Through hole;
[0037] 3. Retaining ring; 31. Opening. Detailed Implementation
[0038] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings. The described embodiments are merely a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort should fall within the protection scope of this application.
[0039] To facilitate understanding of the specific embodiments of this application, a coordinate system is now defined as follows: Figure 2 As shown, the left and right directions are horizontal, the direction is vertical, and the up and down directions are vertical.
[0040] Example 1
[0041] like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, an anti-retrograde expansion interbody fusion device includes a tube body 1 and a tie rod 2 disposed within the tube body 1.
[0042] The pipe body 1 is provided with a plurality of supporting expansion joints 11 and a stabilizing expansion joint 12 along the axial direction, and the stabilizing expansion joint 12 has supporting expansion joints 11 on both sides. As a specific embodiment, in this embodiment, the pipe body 1 is arranged along the direction from left to right (according to...) Figure 2 The coordinate system shown has two support expansion joints 11, one stable expansion joint 12, and one support expansion joint 11 set in sequence.
[0043] The pull rod 2 includes a rod body 21 and a limiting block 22. The rod body 21 is inserted into the tube body 1 from one side (according to...). Figure 2 In the coordinate system shown, the rod 21 is inserted into the tube 1 from the left side, and the limiting block 22 is located on one side of the tube 1 (according to...). Figure 2 In the coordinate system shown, the limiting block 22 is located on the left side of the tube body 1, and the maximum dimension of the limiting block 22 in the plane perpendicular to the axis is greater than the inner diameter of the tube body 1. The limiting block 22 serves as a limiting structure to prevent the pull rod 2 from extending entirely into the tube body 1.
[0044] like Figure 6 , Figure 7 and Figure 8 As shown, a limiting groove 13 is provided on the inner wall of the tube body 1 at the end opposite to the pull rod 2. A retaining ring 3 is provided in the limiting groove 13, and the retaining ring 3 has an opening 31. The rod body 21 of the pull rod 2 is provided with a slot 211 for accommodating the retaining ring 3. Figure 9 As shown, when an anti-retraction expansion interbody fusion device is opened, the retaining ring 3 is sleeved on the rod body 21 and inserted into the slot 211. The tube body 1 is restricted between the limiting block 22 of the pull rod 2 and the retaining ring 3, thereby making the fusion in a stable opened state.
[0045] Furthermore, when an anti-retrograde expansion interbody fusion device is deployed, the end face of the rod 21 is located inside the tube 1 or flush with the end face of the tube 1, thereby avoiding increasing the ineffective dimensions of the fusion device after deployment. As a specific embodiment, in this embodiment, when an anti-retrograde expansion interbody fusion device is deployed, the end face of the rod 21 is flush with the end face of the tube 1.
[0046] Furthermore, such as Figure 6 As shown, the end of the rod 21 has a tapered structure, and the diameter of the tapered structure gradually decreases in the direction away from the limiting block 22. The slot 211 is located on the side of the tapered structure closer to the limiting block 22. In this way, during the process of opening the fusion device, the tapered structure can play a guiding role, so that the rod 21 of the pull rod 2 can pass smoothly through the inner hole of the retaining ring 3.
[0047] Furthermore, such as Figure 7 and Figure 8 As shown, when the retaining ring 3 is in a free state, the outer diameter of the retaining ring 3 is smaller than the diameter of the limiting groove 13 and larger than the inner diameter of the tube body 1, thus reserving space for the expansion of the retaining ring 3. The inner diameter of the retaining ring 3 is smaller than the inner diameter of the tube body 1. When the retaining ring 3 is externally tangent to the limiting groove 13, the end of the rod body 21 can still pass through the inner hole of the retaining ring 3.
[0048] Furthermore, the inner diameter of the retaining ring 3 is less than or equal to the diameter of the slot 211 portion of the rod 21. Thus, when the retaining ring 3 is engaged in the slot 211, it can tightly grip the rod 21, thereby forming a single unit with the pull rod 2.
[0049] Furthermore, such as Figure 1 As shown, one end of the limiting block 22 facing the pull rod 2 of the tube body 1 is provided with a groove for accommodating the limiting block 22. The shape of the groove matches the shape of the limiting block 22, and the cooperation between the groove and the limiting block 22 can restrict the degree of freedom of the pull rod 2 to rotate around its own axis relative to the tube body 1.
[0050] Furthermore, the groove extends through the tube body 1. When the limiting block 22 of the pull rod 2 is located within the groove, the end face of the limiting block 22 is parallel to the end face of the tube body 1, and the limiting block 22 and the tube body 1 form a complete cylindrical surface.
[0051] In one specific embodiment, the groove described in this embodiment penetrates the tube body 1 radially, and the limiting block 22 has a cylindrical structure with two parallel flat openings. When the limiting block 22 of the pull rod 2 is located in the groove, the arc-shaped side of the limiting block 22 and the outer cylindrical surface of the tube body 1 form a complete cylindrical surface.
[0052] Furthermore, the pull rod 2 is provided with a through hole 23 extending axially through the pull rod 2, and the end of the through hole 23 facing the retaining ring 3 is provided with an internal thread, which is used to cooperate with surgical tools.
[0053] Example 2
[0054] The end of the rod 21 has a spherical structure, and the rest of the structure is the same as in Embodiment 1.
[0055] Other embodiments obtained by those skilled in the art based on the embodiments provided in this application by combining, splitting, or reorganizing the embodiments of this application do not exceed the protection scope of this application.
[0056] The above detailed embodiments have provided a detailed explanation of the purpose, technical solutions, and beneficial effects of the embodiments of this application. The above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. That is, any modifications, equivalent substitutions, improvements, etc., made on the basis of the embodiments of this application should be included within the protection scope of the embodiments of this application.
Claims
1. An anti -migration expandable intervertebral fusion cage, comprising: The utility model relates to an intervertebral fusion cage, which comprises a tube body (1) and a pull rod (2). The pull rod (2) comprises a rod body (21) and a limiting block (22), and the rod body (21) is inserted into the tube body (1) from one side. A limiting groove (13) is arranged on the inner side wall of the tube body (1), a stop ring (3) is arranged in the limiting groove (13), a clamping groove (211) is arranged on the rod body (21), and when the intervertebral fusion cage is expanded, the stop ring (3) is sleeved on the rod body (21) and clamped into the clamping groove (211).
2. The anti -retreating expandable interbody fusion cage according to claim 1, wherein: When the intervertebral fusion cage is expanded, the end face of the rod body (21) is located inside the tube body (1) or flush with the end face of the tube body (1).
3. The anti -retreating expandable interbody fusion cage according to claim 1, wherein: The end of the rod body (21) is provided with a guide structure.
4. The anti -retreating expandable interbody fusion cage according to claim 3, wherein: The guide structure is a conical structure or a spherical structure.
5. The anti -migration expandable interbody fusion cage of claim 1, wherein: An opening (31) is arranged on the stop ring (3).
6. The anti -retreating expandable interbody fusion cage according to claim 5, wherein: When the stop ring (3) is in a free state, the outer diameter of the stop ring (3) is smaller than the diameter of the limiting groove (13) and larger than the inner diameter of the tube body (1).
7. The anti -migration expandable interbody fusion cage of claim 5, wherein: The inner diameter of the stop ring (3) is smaller than or equal to the diameter of the clamping groove (211) of the rod body (21).
8. The anti -retreating expandable interbody fusion cage according to claim 1, wherein: The end of the tube body (1) is provided with a groove for accommodating the limiting block (22), and the groove and the limiting block (22) can limit the degree of freedom of rotation of the pull rod (2) relative to the tube body (1).
9. The anti -migration expandable interbody fusion cage according to claim 8, wherein: The groove penetrates the tube body (1), when the limiting block (22) is located in the groove, the end face of the limiting block (22) is parallel to the end face of the tube body (1), and the limiting block (22) and the tube body (1) form a complete cylindrical surface.
10. The anti -migration expandable interbody fusion cage of claim 1, wherein: A plurality of supporting expansion joints (11) and a stabilizing expansion joint (12) are arranged on the tube body (1) in the axial direction, and the stabilizing expansion joint (12) has supporting expansion joints (11) on both sides.