Interbody Fusion Cage

Abstract

The present invention provides an intervertebral fusion device, comprising: a support body; a first fusion plate and a second fusion plate, which are respectively arranged on the upper surface and the lower surface of the support body; and a fastener, which is inserted into the first fusion plate, the support body and the second fusion plate. The technical solution of the present invention can effectively solve the problem of poor stability of the intervertebral fusion device in the related art.

Description

Technical Field

[0001] The present invention relates to the field of intervertebral fusion auxiliary equipment, and in particular to an intervertebral fusion device. Background Art

[0002] Spinal pathological conditions such as degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, tumors, scoliosis and other abnormal curvatures, kyphosis and fractures may be caused by a variety of factors, such as trauma, disease and aging. Spinal conditions often lead to symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility. The surgical treatments for these spinal conditions include fusion, fixation, correction, partial or complete discectomy, etc. Among them, spinal fusion has a good effect on the treatment of more serious spinal conditions. Spinal fusion requires the implantation of an intervertebral fusion cage into the patient's body so that the upper and lower vertebrae that were originally movable are connected together through the fusion cage, thereby achieving the effect of making the intervertebral space more stable.

[0003] The current intervertebral fusion device generally includes a top layer, a bottom layer and a middle layer, and a connection structure is provided between the top layer, the bottom layer and the middle layer. However, the connection strength of the connection structure in the prior art is relatively low. In the early stage of the fusion of the patient's vertebrae and the intervertebral fusion device, the patient's vertebrae and the intervertebral fusion device are not completely fused. At this time, when the patient performs spinal bending movements, the intervertebral fusion device will be subjected to shear force in the anterior-posterior direction and pulling force in the vertical direction. The shear force in the anterior-posterior direction may cause the connection structure of the intervertebral fusion device to break, and the pulling force in the vertical direction may cause the top layer and the bottom layer to flip off the middle layer. Both of these situations will cause the top layer or the bottom layer of the intervertebral fusion device to be at risk of detaching from the middle layer, increasing the chance of postoperative revision of the patient. Summary of the invention

[0004] The main purpose of the present invention is to provide an intervertebral fusion cage to solve the problem of poor stability of the intervertebral fusion cage in the prior art.

[0005] To achieve the above objectives, the present invention provides an intervertebral fusion cage, comprising: a support body; a first fusion plate and a second fusion plate, which are respectively arranged on the upper surface and the lower surface of the support body; and a fastener, which is inserted into the first fusion plate, the support body and the second fusion plate.

[0006] Furthermore, a first mounting hole for passing a fastener is provided on the first fusion plate, the first mounting hole includes a first hole segment and a second hole segment, the diameter of the first hole segment is smaller than the diameter of the second hole segment, and a first step surface is formed between the first hole segment and the second hole segment; a second mounting hole for passing a fastener is provided on the second fusion plate, the second mounting hole includes a third hole segment and a fourth hole segment, the diameter of the third hole segment is smaller than the diameter of the fourth hole segment, and a second step surface is formed between the third hole segment and the fourth hole segment; the fastener includes a fastening rod, a pressure cap arranged at the first end of the fastening rod, and a locking piece arranged at the second end of the fastening rod, the pressure cap abuts against the first step surface, the pressure cap does not protrude from the first mounting hole, the locking piece abuts against the second step surface, and the locking piece does not protrude from the second mounting hole.

[0007] Furthermore, there are three first mounting holes, two of which are located at the front end of the first fusion plate, one of which is located at the rear end of the first fusion plate, and the second mounting holes are arranged corresponding to the first mounting holes.

[0008] Furthermore, the fastener is a rivet, a fixing hole for accommodating the rivet is arranged in the support body, an expansion hole is arranged on the side wall of the rivet located in the fixing hole, and an air path connected to the expansion hole is arranged in the rivet.

[0009] Furthermore, a first through groove concave downward is provided on the upper surface of the support body, and the first fusion plate is arranged in the first through groove; a second through groove concave upward is provided on the lower surface of the support body, and the second fusion plate is arranged in the second through groove.

[0010] Furthermore, the first fusion plate and the second fusion plate each include a plate body and a toothed portion disposed on the plate body, the toothed portion includes a plurality of toothed protrusions, and the plurality of toothed protrusions are arranged at intervals along the front-rear direction of the fusion device.

[0011] Furthermore, the intervertebral fusion device also includes a placement hole that passes through the upper surface of the first fusion plate and the lower surface of the second fusion plate. The plate body includes a solid layer and a porous layer. The solid layer is arranged between the porous layer and the support body. The solid layer includes a solid layer body and reinforcing ribs arranged on the solid layer body. The reinforcing ribs include a first annular rib and a second annular rib located inside the first annular rib. A partial placement hole is formed inside the second annular rib. The porous layer is arranged between the first annular rib and the second annular rib.

[0012] Furthermore, the tooth-shaped protrusion is a solid structure.

[0013] Furthermore, the surface of the first fusion plate facing the support body is a first curved surface, and the surface of the second fusion plate facing the support body is a second curved surface.

[0014] Furthermore, the support body is made of PEEK material, and the first fusion plate and the second fusion plate are made of titanium alloy material.

[0015] By applying the technical solution of the present invention, the intervertebral fusion device can be installed between the upper and lower vertebrae of the patient. The intervertebral fusion device includes a three-layer structure, wherein the first fusion plate contacts the upper vertebrae of the patient, the second fusion plate contacts the lower vertebrae of the patient, and a support body is provided between the first fusion plate and the second fusion plate as a support structure. The design of this multi-layer structure can make the elastic modulus of the intervertebral fusion device closer to the elastic modulus of the patient's vertebrae, thereby facilitating the fusion of the patient's autologous bone with the intervertebral fusion device. Since the fasteners are inserted into the first fusion plate, the support body and the second fusion plate, this fixing method enables the multi-layer structure of the intervertebral fusion device to form a stable whole. When the intervertebral fusion device is subjected to shear force, the multi-layer structures of the intervertebral fusion device have a tendency to move relative to each other. At this time, the fasteners can limit the structures of each layer, thereby ensuring the stability of the intervertebral fusion device. The above structure can improve the strength of the intervertebral fusion device, thereby facilitating the rapid fusion of the patient's autologous bone with the intervertebral fusion device, and facilitating the improvement of the stability of the patient's intervertebral segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the three-dimensional structure of an embodiment of an intervertebral fusion cage according to the present invention is shown;

[0018] Figure 2 Shows Figure 1 A schematic diagram of the three-dimensional structure of a first fusion plate of an intervertebral fusion cage;

[0019] Figure 3 Shows Figure 2 A schematic diagram of the longitudinal structure of the first fusion plate; and

[0020] Figure 4 Shows Figure 1 Schematic diagram of the three-dimensional structure of the second fusion plate of the intervertebral fusion cage.

[0021] The above drawings include the following reference numerals:

[0022] 10. Support body; 11. Fixing hole; 12. First through groove; 13. Second through groove; 20. First fusion plate; 21. First mounting hole; 211. First hole section; 212. Second hole section; 213. First step surface; 22. First arc surface; 30. Second fusion plate; 31. Second mounting hole; 311. Third hole section; 312. Fourth hole section; 313. Second step surface; 32. Second arc surface; 40. Fastener; 41. Fastening rod; 42. Pressing cap; 44. Expansion hole; 50. Plate body; 51. Solid layer; 52. Porous layer; 521. First annular rib; 522. Second annular rib; 60. Toothed portion; 61. Toothed protrusion; 70. Placement hole. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] like Figure 1 As shown, the intervertebral fusion cage of this embodiment includes: a support body 10, a first fusion plate 20, a second fusion plate 30 and a fastener 40. The first fusion plate 20 and the second fusion plate 30 are respectively arranged on the upper surface and the lower surface of the support body 10; the fastener 40 is penetrated in the first fusion plate 20, the support body 10 and the second fusion plate 30.

[0025] By applying the technical solution of this embodiment, the intervertebral fusion device can be installed between the upper and lower vertebrae of the patient. The intervertebral fusion device includes a three-layer structure, wherein the first fusion plate 20 contacts the upper vertebrae of the patient, the second fusion plate 30 contacts the lower vertebrae of the patient, and a support body 10 is provided between the first fusion plate 20 and the second fusion plate 30 as a support structure. The design of this multi-layer structure can make the elastic modulus of the intervertebral fusion device closer to the elastic modulus of the patient's vertebrae, thereby facilitating the fusion of the patient's autologous bone with the intervertebral fusion device. Since the fastener 40 is inserted into the first fusion plate 20, the support body 10 and the second fusion plate 30, this fixing method makes the multi-layer structure of the intervertebral fusion device form a stable whole. When the intervertebral fusion device is subjected to shear force, the multi-layer structures of the intervertebral fusion device have a tendency to move relative to each other. At this time, the fastener 40 can limit each layer structure, thereby ensuring the stability of the intervertebral fusion device. The above structure can improve the strength of the intervertebral fusion device, thereby facilitating the rapid fusion of the patient's autologous bone with the intervertebral fusion device, and facilitating the improvement of the stability of the patient's intervertebral segments.

[0026] In the present embodiment, the support body 10 is made of PEEK material, and the first fusion plate 20 and the second fusion plate 30 are made of titanium alloy material. In the above structure, the titanium alloy material has good compatibility with the patient's autologous bone, which is conducive to the rapid growth of the patient's autologous bone, but the elastic modulus of the titanium alloy material is relatively large, and the use of an intervertebral fusion device made of pure titanium alloy material is likely to cause the intervertebral fusion device to sink into the patient's vertebral body. The elastic modulus of the PEEK material is relatively close to the elastic modulus of the bone, which is conducive to the growth of the patient's bones. However, the compatibility of the PEEK material with the patient's bone cells is poor, and the use of an intervertebral fusion device made of pure PEEK material is likely to cause the patient's autologous bone to be difficult to grow into the intervertebral fusion device. The intervertebral fusion device of the above structure is made of a composite material of titanium alloy and PEEK. The first fusion plate 20 and the second fusion plate 30 in contact with the patient's vertebral body are made of titanium alloy. PEEK material is used as the support body 10 between the first fusion plate 20 and the second fusion plate 30. On the one hand, this improves the compatibility of the intervertebral fusion device with the patient's autologous bone. On the other hand, it makes the elastic modulus of the intervertebral fusion device close to the elastic modulus of the patient's vertebral body, which is conducive to the rapid growth of the patient's autologous bone.

[0027] like Figures 1 to 4 As shown, in this embodiment, the first fusion plate 20 is provided with a first mounting hole 21 for passing the fastener 40, and the first mounting hole 21 includes a first hole section 211 and a second hole section 212. The diameter of the first hole section 211 is smaller than the diameter of the second hole section 212, and a first step surface 213 is formed between the first hole section 211 and the second hole section 212; the second fusion plate 30 is provided with a second mounting hole 31 for passing the fastener 40, and the second mounting hole 31 includes a third hole section 311 and a fourth hole section 312, the diameter of the third hole section 311 is smaller than the diameter of the fourth hole section 312, and a second step surface 313 is formed between the third hole section 311 and the fourth hole section 312; the fastener 40 includes a fastening rod 41, a pressure cap 42 arranged at the first end of the fastening rod 41, and a locking member arranged at the second end of the fastening rod 41, the pressure cap 42 abuts against the first step surface 213, the pressure cap 42 does not protrude from the first mounting hole 21, the locking member abuts against the second step surface 313, and the locking member does not protrude from the second mounting hole 31. In the above structure, the pressure cap 42 and the locking member of the fastener 40 can limit the first fusion plate 20, the second fusion plate 30 and the support body 10 in the vertical direction to prevent the first fusion plate 20 and the second fusion plate 30 from being separated from the support body 10. In addition, the pressing cap 42 does not protrude from the first mounting hole 21, and the locking piece does not protrude from the second mounting hole 31, so that the first fusion plate 20 and the second fusion plate 30 can better fit the patient's vertebral body, thereby facilitating the rapid growth of the patient's own bone into the intervertebral fusion device and improving the stability of the patient's intervertebral segment.

[0028] like Figure 1 , Figure 2 and Figure 4As shown, in this embodiment, there are three first mounting holes 21, two of the three first mounting holes 21 are located at the front end of the first fusion plate 20, one of the three first mounting holes 21 is located at the rear end of the first fusion plate 20, and the second mounting hole 31 is arranged corresponding to the first mounting hole 21. In the above structure, the number of the first mounting holes 21 and the second mounting holes 31 is the same as the number of the fasteners 40. The fasteners 40 are inserted into the first mounting holes 21 and the second mounting holes 31. There are three fasteners 40, and the three fasteners 40 are distributed in a triangular shape. This distribution method can improve the fastening effect of the fasteners 40 on the intervertebral fusion device, thereby increasing the stability of the intervertebral fusion device and facilitating the rapid growth of the patient's own bone. It should be noted that a fastener 40 arranged at the rear end of the intervertebral fusion device is located on the center line of the line connecting the two fasteners 40 arranged at the front end of the intervertebral fusion device. This method can further improve the fastening effect of the fasteners 40.

[0029] Since the thickness of the first fusion plate 20 and the second fusion plate 30 is relatively small, when installing the fastener 40, it is necessary to avoid fastening the fastener 40 too tightly to the intervertebral fusion cage in the vertical direction to prevent the first fusion plate 20 and the second fusion plate 30 from deforming. However, this method may cause the fastener 40 to move up and down in the intervertebral fusion cage. Figure 1 As shown, in this embodiment, the fastener 40 is a rivet, and a fixing hole 11 for accommodating the rivet is provided in the support body 10, and an expansion hole 44 is provided on the side wall of the rivet located in the fixing hole 11, and an air path connected to the expansion hole 44 is provided in the rivet. In the above structure, when installing the fastener 40, the fastener is first inserted into the first fusion plate 20, the support body 10 and the second fusion plate 30, and then high-pressure gas is filled into the air path. The high-pressure gas will escape from the expansion hole 44, so that the fastening rod 41 at the expansion hole 44 will expand and deform, so that the fastening rod 41 and the fixing hole 11 are more closely matched, thereby reducing the probability of the fastener 40 moving up and down in the intervertebral fusion cage. Of course, in other embodiments not shown in the figure, the fastener 40 can also be riveted in a traditional riveting form, such as punch riveting or rotary riveting.

[0030] like Figure 1As shown, in this embodiment, the upper surface of the support body 10 is provided with a first through groove 12 which is concave downwards, and the first fusion plate 20 is arranged in the first through groove 12; the lower surface of the support body 10 is provided with a second through groove 13 which is concave upwards, and the second fusion plate 30 is arranged in the second through groove 13. In the above structure, the front groove wall and the rear groove wall of the first through groove 12 can limit the first fusion plate 20 in the front-back direction, and prevent the first fusion plate 20 from slipping off the support body 10 when the intervertebral fusion cage is subjected to shear force in the front-back direction, thereby improving the stability of the intervertebral fusion cage. Accordingly, the second through groove 13 is provided on the lower surface of the support body 10, which can also play the effect of limiting the second fusion plate 30.

[0031] like Figure 1 As shown, in this embodiment, the first fusion plate 20 and the second fusion plate 30 both include a plate body 50 and a toothed portion 60 disposed on the plate body 50, the toothed portion 60 includes a plurality of toothed protrusions 61, and the plurality of toothed protrusions 61 are arranged at intervals along the front-back direction of the fusion device. In the above structure, in the early stage of spinal fusion, when the patient performs spinal flexion exercise, the intervertebral fusion device may move between the patient's vertebrae, which is not conducive to the rapid growth of the patient's autologous bone into the intervertebral fusion device. The toothed portion 60 includes a plurality of toothed protrusions 61, and the toothed protrusions 61 can increase the friction between the intervertebral fusion device and the patient's vertebrae, thereby reducing the probability of the intervertebral fusion device moving between the patient's vertebrae and improving the rate of intervertebral fusion of the patient.

[0032] like Figures 1 to 4As shown, in this embodiment, the intervertebral fusion device also includes a placement hole 70 that passes through the upper surface of the first fusion plate 20 and the lower surface of the second fusion plate 30, the plate body 50 includes a solid layer 51 and a porous layer 52, the solid layer 51 is arranged between the porous layer 52 and the support body 10, the solid layer 51 includes a solid layer body and reinforcing ribs arranged on the solid layer body, the reinforcing ribs include a first annular rib 521 and a second annular rib located inside the first annular rib 521, a partial placement hole 70 is formed inside the second annular rib 522, and the porous layer 52 is arranged between the first annular rib 521 and the second annular rib 522. In the above structure, the placement hole 70 and the porous layer 52 can be filled with the patient's autologous bone as an implant, and the porous layer 52 has a fine pore structure that is interconnected. This structure makes the surface of the porous layer 52 relatively rough, thereby increasing the contact area between the patient's upper and lower vertebrae and the porous layer 52, thereby increasing the probability of the upper and lower vertebrae contacting the implant, and improving the fusion speed of the patient's upper and lower vertebrae and the intervertebral fusion device. However, due to the low strength of the porous layer 52, the overall porous structure design of the first fusion plate 20 or the second fusion plate 30 will make the strength of the first fusion plate 20 and the second fusion plate 30 low and prone to deformation. The above structure uses a solid layer 51 as a basis, and the reinforcement ribs are arranged on the solid layer 51 to increase the strength of the first fusion plate 20 and the second fusion plate 30, and reduce the probability of the first fusion plate 20 and the second fusion plate 30 being deformed.

[0033] It should be noted that the pore size of the fine pore structure in the porous layer 52 is between 500-1200 μm, preferably, the pore size of the fine pore structure is 800 μm. The thickness of the porous layer 52 is between 0.5 mm and 0.6 mm.

[0034] It should be noted that a third annular rib is provided on the circumferential outer side of the first mounting hole 21 of the first fusion plate 20, and the third annular rib can further enhance the strength of the first fusion plate 20, and prevent the first fusion plate 20 from being deformed by the fastening action of the fastener 40, thereby affecting the fit between the first fusion plate 20 and the upper vertebral segment. Correspondingly, a fourth annular rib is provided on the circumferential outer side of the second mounting hole 31 of the second fusion plate 30, and the fourth annular rib can further enhance the strength of the second fusion plate 30, and prevent the second fusion plate 30 from being deformed by the fastening action of the fastener 40, thereby affecting the fit between the second fusion plate 30 and the lower vertebral segment.

[0035] like Figure 1 As shown, in this embodiment, the tooth-shaped protrusion 61 is a solid structure. The above structure can improve the strength of the tooth-shaped portion 60, thereby increasing the overall strength of the first fusion plate 20 and the second fusion plate 30.

[0036] like Figure 1As shown, in this embodiment, the surface of the first fusion plate 20 facing the support body 10 is the first curved surface 22, and the surface of the second fusion plate 30 facing the support body 10 is the second curved surface 32. In the above structure, the contact surface between the first fusion plate 20 and the support body 10 is the first curved surface 22. The curved surface makes the contact area between the first fusion plate 20 and the support body 10 larger, which is conducive to dispersing the load between the first fusion plate 20 and the support body 10, and reduces the probability of deformation of the first fusion plate 20. Correspondingly, the contact surface between the second fusion plate 30 and the support body 10 is the second curved surface 32, and the second curved surface 32 can also play the same effect as the first curved surface 22.

[0037] It should be noted that the upper surface of the first fusion plate 20 is designed as an arc surface, which makes the first fusion plate 20 better fit the upper vertebra of the patient. Correspondingly, the lower surface of the second fusion plate 30 is designed as an arc surface, which improves the fit of the second fusion plate 30 and the lower vertebra of the patient.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intervertebral fusion cage, characterized in that: include: A support body (10), wherein the support body (10) is made of PEEK material; A first fusion plate (20) and a second fusion plate (30) are respectively arranged on the upper surface and the lower surface of the support body (10); A fastener (40) is inserted into the first fusion plate (20), the support body (10) and the second fusion plate (30); The first fusion plate (20) is provided with a first mounting hole (21) for inserting a fastener (40), the first mounting hole (21) comprising a first hole section (211) and a second hole section (212), the diameter of the first hole section (211) being smaller than the diameter of the second hole section (212), and a first step surface (213) being formed between the first hole section (211) and the second hole section (212); The second fusion plate (30) is provided with a second mounting hole (31) for inserting a fastener (40), the second mounting hole (31) comprising a third hole section (311) and a fourth hole section (312), the diameter of the third hole section (311) being smaller than the diameter of the fourth hole section (312), and a second step surface (313) being formed between the third hole section (311) and the fourth hole section (312); The fastener (40) comprises a fastening rod (41), a pressing cap (42) arranged at a first end of the fastening rod (41), and a locking piece arranged at a second end of the fastening rod (41), the pressing cap (42) abutting against the first step surface (213), the pressing cap (42) not protruding from the first mounting hole (21), the locking piece abutting against the second step surface (313), the locking piece not protruding from the second mounting hole (31); The fastener (40) is a rivet, the support body (10) is provided with a fixing hole (11) for accommodating the rivet, an expansion hole (44) is provided on a side wall of the rivet located in the fixing hole (11), and an air path communicating with the expansion hole (44) is provided in the rivet; When installing the fastener (40), the fastener is first inserted into the first fusion plate (20), the support body (10) and the second fusion plate (30), and then high-pressure gas is filled into the gas path. The high-pressure gas escapes from the expansion hole (44), thereby causing the fastening rod (41) at the expansion hole (44) to expand and deform.

2. The intervertebral fusion cage according to claim 1, characterized in that: There are three first mounting holes (21), two of the three first mounting holes (21) are located at the front end of the first fusion plate (20), one of the three first mounting holes (21) is located at the rear end of the first fusion plate (20), and the second mounting holes (31) are arranged corresponding to the first mounting holes (21).

3. The intervertebral fusion cage according to claim 1, characterized in that: The upper surface of the support body (10) is provided with a first through groove (12) which is concave downwards, and the first fusion plate (20) is arranged in the first through groove (12); The lower surface of the support body (10) is provided with a second through groove (13) which is concave upwards, and the second fusion plate (30) is arranged in the second through groove (13).

4. The intervertebral fusion cage according to claim 1, characterized in that: The first fusion plate (20) and the second fusion plate (30) both comprise a plate body (50) and a toothed portion (60) arranged on the plate body (50), the toothed portion (60) comprising a plurality of toothed protrusions (61), the plurality of toothed protrusions (61) being arranged at intervals along the front-back direction of the intervertebral fusion cage.

5. The intervertebral fusion cage according to claim 4, characterized in that: The intervertebral fusion device also includes a placement hole (70) that passes through the upper surface of the first fusion plate (20) and the lower surface of the second fusion plate (30); the plate body (50) includes a solid layer (51) and a porous layer (52); the solid layer (51) is arranged between the porous layer (52) and the support body (10); the solid layer (51) includes a solid layer body and reinforcing ribs arranged on the solid layer body; the reinforcing ribs include a first annular rib (521) and a second annular rib (522) located inside the first annular rib (521); a portion of the placement hole (70) is formed inside the second annular rib (522); and the porous layer (52) is arranged between the first annular rib (521) and the second annular rib (522).

6. The intervertebral fusion cage according to claim 4, characterized in that: The tooth-shaped protrusion (61) is a solid structure.

7. The intervertebral fusion cage according to claim 1, characterized in that: The surface of the first fusion plate (20) facing the support body (10) is a first arc-shaped surface (22), and the surface of the second fusion plate (30) facing the support body (10) is a second arc-shaped surface (32).

8. The intervertebral fusion cage according to claim 1, characterized in that: The first fusion plate (20) and the second fusion plate (30) are made of titanium alloy.

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