Interarticular fusion cage

Abstract

The present application discloses an interarticular fusion device, wherein the interarticular fusion device comprises a support portion (10) and a head portion (20) and a tail portion (30) respectively arranged at both ends of the support portion (10), wherein the head portion (20) gradually shrinks from the support portion (10) along the support height direction of the support portion (10) and forms a tip structure (21) at the end. The tip structure of the head portion can guide the interarticular fusion device into a joint space with a smaller gap, thereby improving the convenience of the implantation operation and reducing the difficulty of the operation.

Description

Technical Field

[0001] The present application relates to the field of surgical medical instruments, and more particularly, to an interarticular fusion device. Background Art

[0002] Spinal fusion often involves dorsolateral bone grafting, which requires removal of cortical bone from the lateral articular surface of the spine to create a graft bed and a large amount of bone grafting. However, due to the lack of compressive stress stimulation, the grafted cancellous bone will be absorbed, resulting in a low fusion rate.

[0003] In theory, a fusion device can be placed in the spinal joint space to improve the success rate of bone graft fusion and moderately expand the joint space, thereby improving spinal stenosis. In the prior art, intervertebral fusion devices are commonly used implants in the field of spinal surgery. When used, the intervertebral fusion device is placed in the intervertebral space of the spine to support and stabilize the anterior column, expand the intervertebral space, and restore the height of the intervertebral foramen. However, the intervertebral space of the spine is larger than the intervertebral joint space, and the intervertebral fusion device is difficult to place in the intervertebral joint space.

[0004] Similarly, it is also difficult to implant an interbody fusion device suitable for the lumbar vertebrae in the lumbar joint space.

[0005] Therefore, how to provide a fusion device suitable for implantation into a joint gap becomes a technical problem that needs to be solved in this field. Summary of the Invention

[0006] In view of this, the present application proposes an interarticular fusion cage suitable for implantation into the joint space.

[0007] According to the present application, an interarticular fusion device is proposed, wherein the interarticular fusion device includes a support portion and a head and a tail portion respectively arranged at both ends of the support portion, the head portion gradually shrinks from the support portion along the support height direction of the support portion and forms a tip structure at the end.

[0008] Optionally, the head has a symmetrically inclined upper surface and a lower surface, and the upper surface and the lower surface are planes.

[0009] Optionally, the upper surface and the lower surface form an angle α of 25°-35°; and / or the tip of the tip structure has a smooth surface.

[0010] Optionally, the widths of the upper surface and the lower surface are the same as the width of the connection between the support portion and the head portion; and / or, the widths of the upper surface and the lower surface are 6 mm-10 mm.

[0011] Optionally, the support portion includes a support top surface and a support bottom surface that are opposite to each other along the support height direction, and the support top surface and the support bottom surface are provided with a rough structure for increasing friction.

[0012] Optionally, the support top surface and the support bottom surface are symmetrically inclined close to each other along a direction from the head portion to the tail portion, and an angle between the support top surface and the support bottom surface is 10°-20°.

[0013] Optionally, the interarticular fusion device is an integral piece and includes a top surface, a bottom surface, and a side surface connecting the top surface and the bottom surface opposite to each other along the support height direction. The interarticular fusion device has a hollow structure, wherein: the top surface and the bottom surface are provided with a first through hole P1 connected to the hollow structure, and the side surface is provided with a second through hole P2 connected to the hollow structure; and / or the top surface and / or the bottom surface are provided with a socket P3.

[0014] Optionally, the tail includes a tail top surface and a tail bottom surface opposite to each other along the support height direction, the tail top surface and the tail bottom surface extend close to each other along the direction from the head to the tail, and the minimum angle β between the tail top surface and the tail bottom surface does not exceed 20°.

[0015] Optionally, the tail portion includes a rear end face, and the rear end face is provided with a connection structure for connecting to a conveying tool.

[0016] Optionally, the total length of the interarticular fusion cage is 9mm-15mm, the width is 7mm-9mm, and the height is 2mm-10mm, and the head occupies 1 / 3 to 1 / 2 of the total length of the interarticular fusion cage.

[0017] According to the technical solution of the present application, the tip structure of the head can be used to guide the interarticular fusion device into a joint space with a smaller gap, thereby improving the convenience of the implantation operation and reducing the difficulty of the operation.

[0018] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute part of this application, are used to provide a further understanding of the application, and the exemplary embodiments of the application and their descriptions are used to explain the application. In the accompanying drawings:

[0020] Figure 1 It is a front view of an interarticular fusion cage according to a preferred embodiment of the present application;

[0021] Figure 2 for Figure 1 Top view of the interarticular fusion cage;

[0022] Figure 3 for Figure 1 Right view of the interarticular fusion cage;

[0023] Figure 4 This is a picture showing the distraction of the lumbar joint space;

[0024] Figure 5 This is a picture showing the implantation of an interarticular fusion cage;

[0025] Figure 6 This is a preoperative X-ray showing atlantoaxial dislocation;

[0026] Figure 7 This is an X-ray image showing the implantation of an interarticular fusion cage;

[0027] Figure 8 This is an X-ray image showing a period of time after the implantation of the arthrodesis cage. DETAILED DESCRIPTION

[0028] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with the implementation methods.

[0029] The present application provides an interarticular fusion device, wherein the interarticular fusion device 100 includes a support portion 10 and a head portion 20 and a tail portion 30 respectively arranged at both ends of the support portion 10, the head portion 20 gradually shrinks from the support portion 10 along the support height direction of the support portion 10 and forms a tip structure 21 at the end.

[0030] Herein, the “support height direction” refers to the height direction of the support portion 10 , and is also the direction of the supporting force exerted by the support portion 10 on the joint surfaces on both sides.

[0031] By using the interarticular fusion device 100 of the present application, the tip structure 21 of the head 20 can be used to guide the interarticular fusion device into a joint space with a smaller gap, thereby improving the convenience of the implantation operation and reducing the difficulty of the operation.

[0032] Specifically, during implantation, the tip structure 21 can first enter the narrow joint gap. As the interarticular fusion device is advanced as a whole, the tip structure 21 can gradually expand the joint gap, allowing the support portion 10 to enter and ultimately be supported at the joint gap.

[0033] In the present application, the head 20 can be tapered in an appropriate manner to form the tip structure 21. For example, the head 20 can be tapered in a cone shape. Preferably, in order to avoid applying excessive pressure to the expanded joint surface while forming the tip structure 21, as shown in FIG. Figure 1As shown, the head 20 has a symmetrically inclined upper surface 22 and a lower surface 23, each of which is a plane. Thus, the symmetrically inclined upper and lower surfaces 22, 23 form a tip structure 21 at their respective ends, which gradually tapers at the distal end. Furthermore, the planar upper and lower surfaces 22, 23 allow the tip structure 21 to contact the expanded joint surface, thereby facilitating entry of the interarticular fusion device into the joint space while preventing damage to the joint surface due to excessive pressure on the joint surface.

[0034] In order to gradually expand the joint gap through the tip structure 21 and thus gradually increase the pressure on the joint surface, the upper surface 22 and the lower surface 23 can be made to have a suitable inclination angle. Preferably, the upper surface 22 and the lower surface 23 form an angle α of 25°-35°.

[0035] In addition, to prevent the tip of the tip structure 21 from causing unnecessary damage to the joint surface, the tip of the tip structure 21 may have a smooth surface. Specifically, when manufacturing the interarticular fusion cage, the tip of the tip structure 21 may be rounded or processed accordingly.

[0036] To balance the implantation guidance effect of the tip structure 21 and the stabilization and support of the joint gap by the upper and lower surfaces 22 and 23, the proportion of the tip structure 21 to the head 20 can be reasonably set. For example, along the extension direction of the upper and lower surfaces 22 and 23, the tip structure 21 occupies 1 / 5 to 1 / 3 of the length of the head 20.

[0037] As described above, to avoid excessive pressure on the expanded joint surface, the head portion 20 contacts the joint surface via its upper surface 22 and lower surface 23. To this end, the upper surface 22 and lower surface 23 can be made sufficiently wide. For example, the widths of the upper surface 22 and lower surface 23 can be 6 mm to 10 mm. Furthermore, for ease of manufacture, the widths of the upper surface 22 and lower surface 23 can be made the same as the width of the support portion 10 at its connection to the head portion 20. Preferably, the support portion 10, the head portion 20, and the tail portion 30 can have a continuous and consistent width.

[0038] In addition, preferably, Figure 1 and Figure 2 As shown, the support portion 10 includes a top support surface 11 and a bottom support surface 12, which are opposed to each other along the support height direction. These top and bottom support surfaces 11, 12 may be provided with a roughened structure 13 for increasing friction. The roughened structure 13 increases friction between the top and bottom support surfaces 11, 12 and the bony articular surface between the joints, preventing displacement of the joint fusion cage after implantation. The roughened structure 13 may take any suitable form, such as tooth-like protrusions.

[0039] Preferably, if Figure 2 As shown, the support top surface 11 and the support bottom surface 12 are symmetrically inclined close to each other along the direction from the head 20 to the tail 30 to prevent the interarticular fusion device from exiting the joint space in the opposite direction of the implantation direction. The inclination of the support top surface 11 and the support bottom surface 12 should not be too much, so as not to affect the contact effect with the joint surface. For example, the angle between the support top surface 11 and the support bottom surface 12 can be 10°-20°. The protrusion heights of the tooth-shaped protrusions on the support top surface 11 and the support bottom surface 12 can be the same, and the extension direction of the support top surface 11 and the support bottom surface 12 can be determined by the connecting line of the vertices of the tooth-shaped protrusions provided thereon.

[0040] In the present application, the interarticular fusion device can be a one-piece or an assembled part. For ease of manufacture, the interarticular fusion device is preferably a one-piece part. The interarticular fusion device may include a top surface, a bottom surface and a side surface connecting the top surface and the bottom surface relative to each other along the support height direction. The interarticular fusion device has a hollow structure (in Figure 1 and Figure 2 In the illustrated embodiment, the hollow structure can be provided across the support portion 10 and the head portion 20. First through-holes P1 are provided on the top and bottom surfaces, connecting to the interior of the hollow structure, while second through-holes P2 are provided on the side surfaces, connecting to the interior of the hollow structure. The provision of first through-holes P1 and second through-holes P2 facilitates bone ingrowth and allows for fusion of the interarticular fusion cage with the bone.

[0041] The top surface and / or bottom surface of the interarticular fusion device of the present application may be provided with a plug hole P3 for inserting a developing metal wire, so as to facilitate tracking and observing the position and status of the interarticular fusion device after implantation.

[0042] In addition, if Figure 1 and Figure 3 As shown, the tail 30 includes a tail top surface 31 and a tail bottom surface 32 that are opposite to each other along the support height direction, and the tail top surface 31 and the tail bottom surface 32 extend close to each other in the direction from the head 20 to the tail 30, thereby forming a lordosis angle, which helps the affected part to restore physiological lordosis. Wherein, the tail top surface 31 and the tail bottom surface 32 can be formed as a curved surface or a plane to extend close to each other in the direction from the head 20 to the tail 30. When the tail top surface 31 and the tail bottom surface 32 are planes, the lordosis angle is the angle between the tail top surface 31 and the tail bottom surface 32. When the tail top surface 31 and the tail bottom surface 32 are curved surfaces, as shown in FIG. Figure 3As shown, the lordosis angle is the minimum value of the angle formed by the cross-section of the tail top surface 31 and the cross-section of the tail bottom surface 32. Regardless of whether the tail top surface 31 and the tail bottom surface 32 are flat or curved, to help the affected area restore physiological lordosis, the minimum angle β between the tail top surface 31 and the tail bottom surface 32 (when the tail top surface 31 and the tail bottom surface 32 are flat, the minimum angle β is the angle between the tail top surface 31 and the tail bottom surface 32; when the tail top surface 31 and the tail bottom surface 32 are curved, the minimum angle β is the minimum value of the angle formed by the cross-section of the tail top surface 31 and the tail bottom surface 32) does not exceed 20°.

[0043] like Figure 3 As shown, the tail 30 includes a rear end face, and the rear end face is provided with a connecting structure 33 for connecting a conveying tool. During use, the interarticular fusion device can be connected to the conveying tool via the connecting structure 33 so that the interarticular fusion device can be delivered into the joint space via the conveying tool. The conveying tool can have an adapter structure that cooperates with the connecting structure 33 for connection and disassembly, thereby ensuring a firm connection between the conveying tool and the interarticular fusion device during implantation, and being able to conveniently release the connection between the conveying tool and the interarticular fusion device after implantation so that the conveying tool can be withdrawn. For example, the connecting structure 33 and the adapter structure can be threadedly connected so that the connection can be conveniently released by rotating the conveying tool after implantation. The conveying tool can be in the shape of a slender rod that is convenient for implantation, and the adapter structure can be arranged at one end of the length direction of the conveying tool.

[0044] In order to facilitate implantation in a narrow joint gap, the size of the interarticular fusion device of the present application should be set to be suitable for matching the joint gap. Specifically, the total length of the interarticular fusion device (the length in the direction from the head 20 to the tail 30) is 9mm-15mm, the width is 7mm-9mm, and the height is 2mm-10mm. In addition, in order to take into account the functions of the guided implantation of the head 20 and other parts of the interarticular fusion device, the head 20 accounts for 1 / 3 to 1 / 2 of the total length of the interarticular fusion device. Preferably, the length of the support portion 10, the head 20 and the tail 30 each accounts for about 1 / 3 of the total length, so as to take into account the support portion 10's support and the connection and lordosis recovery of the tail 30.

[0045] The interarticular fusion device of the present application can be used for implantation in spinal joint spaces (including spinal joint spaces, thoracic joint spaces, and lumbar joint spaces). It is understandable that for use in joint spaces at different locations, an interarticular fusion device of appropriate specifications can be selected according to the specific implanted joint space.

[0046] The following describes the implantation operation of the interarticular fusion device of the present application by taking a trial operation of implanting the interarticular fusion device of the present application in the lumbar vertebral joint space as an example.

[0047] First, if Figure 4As shown, the joint spreader S is inserted into the lumbar vertebral articular surface to spread the joint gap. During the spreading process, the integrity of the bony articular surfaces of the upper and lower articular surfaces must be ensured. After the joint gap is spread to a predetermined height, the cartilage on the articular surface is scraped off with a joint surface scraper to expose the bony articular surface. Subsequently, the interarticular fusion device 100 can be delivered into the gap between the bony articular surfaces of the upper and lower articular surfaces by a delivery tool, so that the support portion 10 enters the gap under the guidance of the head 20 and is supported between the bony articular surfaces of the upper and lower articular surfaces, completing the implantation of the interarticular fusion device 100, as shown in FIG. Figure 5 As shown. Figure 7 It can be seen that the interarticular fusion cage 100 matches the joint space well.

[0048] The following describes the implantation operation of the interarticular fusion device of the present invention by taking a trial operation of implanting the interarticular fusion device of the present invention in the atlantoaxial lateral mass joint space as an example.

[0049] First, insert the joint expander into the atlantoaxial joint surface to expand the joint gap and release the tension band in front of the atlantoaxial joint. During the expansion process, the integrity of the bony joint surfaces of the upper and lower joint surfaces must be ensured. After the joint gap is expanded to a predetermined height, use a joint scraper to scrape off the cartilage on the joint surface to expose the bony joint surface. The interarticular fusion device can then be delivered into the gap between the bony joint surfaces of the upper and lower joint surfaces through a delivery tool, so that the support portion 10 enters the gap under the guidance of the head 20 and is supported between the bony joint surfaces of the upper and lower joint surfaces, completing the implantation of the interarticular fusion device. The patient's atlantoaxial dislocation condition (i.e., before implantation) is as follows: Figure 6 As shown, Figure 7 The figure shows the situation after the interarticular fusion cage 100 is implanted. Figure 7 It can be seen that the interarticular fusion cage 100 matches the joint space well. Figure 8 The figure shows the situation after a period of time of implantation of the interarticular fusion device 100. It can be seen that a strong bone fusion is formed in the joint space, thanks to the promotion of interarticular bone fusion by the interarticular fusion device 100.

[0050] The preferred embodiments of the present application are described in detail above. However, the present application is not limited to the specific details of the above embodiments. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the scope of protection of the present application.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner unless there is any contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

[0052] In addition, the various implementation methods of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

Claims

1. An interarticular fusion device, characterized in that: The interarticular fusion device (100) comprises a support portion (10) and a head portion (20) and a tail portion (30) respectively arranged at both ends of the support portion (10), wherein the head portion (20) gradually contracts from the support portion (10) along the support height direction of the support portion (10) and forms a tip structure (21) at the end. The tail portion (30) includes a tail top surface (31) and a tail bottom surface (32) that are opposite to each other along the support height direction, the tail top surface (31) and the tail bottom surface (32) extend close to each other along the direction from the head portion (20) to the tail portion (30), and the minimum angle β between the tail top surface (31) and the tail bottom surface (32) does not exceed 20°. The tail portion (30) comprises a rear end face, and the rear end face is provided with a connection structure (33) for connecting to a conveying tool.

2. The interarticular fusion cage according to claim 1, characterized in that: The head (20) has a symmetrically inclined upper surface (22) and a lower surface (23), and the upper surface (22) and the lower surface (23) are planes.

3. The interarticular fusion cage according to claim 2, characterized in that: The upper surface (22) and the lower surface (23) form an angle α of 25°-35°; and / or the tip of the tip structure (21) has a smooth surface.

4. The interarticular fusion cage according to claim 2, characterized in that: The widths of the upper surface (22) and the lower surface (23) are the same as the width of the connection between the support portion (10) and the head portion (20); and / or the widths of the upper surface (22) and the lower surface (23) are 6 mm to 10 mm.

5. The interarticular fusion cage according to claim 1, characterized in that: The support portion (10) comprises a support top surface (11) and a support bottom surface (12) that are opposite to each other along the support height direction; the support top surface (11) and the support bottom surface (12) are provided with a rough structure (13) for increasing friction.

6. The interarticular fusion cage according to claim 5, characterized in that: The support top surface (11) and the support bottom surface (12) are symmetrically inclined close to each other in a direction from the head portion (20) to the tail portion (30), and the included angle between the support top surface (11) and the support bottom surface (12) is 10°-20°.

7. The interarticular fusion cage according to claim 1, characterized in that: The interarticular fusion device is a one-piece component and includes a top surface, a bottom surface, and a side surface connecting the top surface and the bottom surface, which are opposite to each other along the support height direction. The interarticular fusion device has a hollow structure, wherein: the top surface and the bottom surface are provided with a first through hole P1 connected to the hollow structure, and the side surface is provided with a second through hole P2 connected to the hollow structure; and / or the top surface and / or the bottom surface are provided with a socket P3.

8. The interarticular fusion cage according to any one of claims 1 to 7, characterized in that: The total length of the interarticular fusion device is 9 mm to 15 mm, the width is 7 mm to 9 mm, and the height is 2 mm to 10 mm. The head (20) occupies 1 / 3 to 1 / 2 of the total length of the interarticular fusion device.

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