Expandable intervertebral fusion cage

Abstract

The present invention discloses an expandable intervertebral fusion device, belonging to the technical field of orthopedic implants, the expandable intervertebral fusion device comprises a fusion device main frame, an expander body is arranged above and / or below the fusion device main frame, the expander body is provided with a porous structure or convex teeth, two sets of expander structures are arranged side by side in the left and right sides of the fusion device main frame, one of the two expander structures is connected to the left side of the expander body by driving, and the other is connected to the right side of the expander body by driving, so as to adjust the expansion height of the left or right side of the expander body respectively through the two expander structures, at least one set of the expander structure comprises a driving shaft and a push block sleeved on the driving shaft, a connecting rod is arranged between the push block and the expander body, and the two ends of the connecting rod are respectively hinged to the push block and the expander body. The expandable intervertebral fusion device of the present invention can treat scoliosis of the intervertebral disc, relieve compression, restore the height and tension of the vertebral segment, restore the physiological curvature of the spine, and ensure the stability of the spine.

Description

Technical Field

[0001] The invention relates to the technical field of orthopedic implants, in particular to an expandable intervertebral fusion device. Background Art

[0002] Lumbar interbody fusion can effectively treat lumbar degeneration and instability. It can fuse the upper and lower vertebrae, maintain the height of the intervertebral space, reduce the pressure on the nerve roots, and maintain the stability of the spine. It has satisfactory clinical effects, small surgical trauma, and easy operation.

[0003] In recent years, with the promotion of clinical applications and progress in theoretical research, it has gradually been discovered that conventional fusion devices still have certain shortcomings, such as poor self-stabilization performance of intervertebral implants and unsatisfactory recovery of lumbar physiological lordosis after vertebral fusion surgery.

[0004] To solve these problems, an expandable intervertebral fusion device is currently used. Although the expandable intervertebral fusion devices currently available on the market can effectively ensure the height of the intervertebral space and alleviate the symptoms caused by the compression of the vertebral body, they are basically expanded to the front and back sides, which is insufficient in treating symptoms such as scoliosis. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an expandable intervertebral fusion device capable of treating scoliosis of the intervertebral disc.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] An expandable intervertebral fusion device comprises a fusion device main frame, an expander body is arranged above and / or below the fusion device main frame, and a porous structure or convex teeth are arranged on the expander body, wherein:

[0008] Two sets of expansion structures are arranged side by side on the left and right sides of the fusion device main frame, one of the two expansion structures is connected to the left side of the expansion body by driving, and the other is connected to the right side of the expansion body by driving, so that the expansion height of the left or right side of the expansion body can be adjusted respectively through the two expansion structures. At least one of the expansion structures includes a driving shaft and a push block sleeved on the driving shaft and driven by the driving shaft to move along the length direction of the fusion device main frame. A connecting rod is arranged between the push block and the expansion body, and the two ends of the connecting rod are respectively hinged to the push block and the expansion body.

[0009] Furthermore, at least one of the expansion body and the connecting rod and the push block and the connecting rod is a multi-degree-of-freedom hinge structure, and the multi-degree-of-freedom hinge structure allows the connecting rod to swing back and forth in the vertical direction relative to the fusion device main frame, and the expansion body to swing left and right in the vertical direction relative to the push block.

[0010] Furthermore, a multi-degree-of-freedom hinge structure is formed between the expansion body and the connecting rod, and the multi-degree-of-freedom hinge structure enables the connecting rod to swing forward and backward in the vertical direction relative to the expansion body, and enables the expansion body to swing left and right in the vertical direction relative to the connecting rod;

[0011] Alternatively, a multi-degree-of-freedom hinge structure is formed between the push block and the connecting rod, and the multi-degree-of-freedom hinge structure enables the connecting rod to swing forward and backward in the vertical direction relative to the push block, and to swing left and right in the vertical direction relative to the push block.

[0012] Furthermore, a rotating shaft extending along the length direction of the support body is fixedly provided on the side surface of the support body, a hinge block is rotatably mounted on the rotating shaft, and the upper end of the connecting rod is hinged to the hinge block, so that the multi-degree-of-freedom hinge structure is formed between the support body and the connecting rod;

[0013] Alternatively, the side surface of the expansion body is rotatably equipped with a rotating shaft extending along its length direction, the rotating shaft is fixedly provided with a hinge block, and the upper end of the connecting rod is hinged to the hinge block, so that the multi-degree-of-freedom hinge structure is formed between the expansion body and the connecting rod;

[0014] Alternatively, the upper end of the connecting rod is spherically hinged to the side surface of the expansion body.

[0015] Furthermore, a groove is provided on the side surface of the expansion body, and the hinge block is located in the groove.

[0016] Furthermore, the expansion body includes an upper expansion body located above the main frame of the fusion device, wherein one expansion structure includes a first drive shaft and a first push block sleeved on the first drive shaft and driven by the first drive shaft to move along the length direction of the first drive shaft, and another expansion structure includes a second drive shaft and a second push block sleeved on the second drive shaft and driven by the second drive shaft to move along the length direction of the second drive shaft, and the connecting rod includes a first upper connecting rod hingedly arranged between the first push block and one side of the upper expansion body, and a second upper connecting rod hingedly arranged between the second push block and the other side of the upper expansion body;

[0017] And / or, the expansion body includes a lower expansion body located below the fusion device main body frame, wherein one expansion structure includes a third driving shaft and a third push block sleeved on the third driving shaft and driven by the third driving shaft to move along the length direction of the third driving shaft, and the other expansion structure includes a fourth driving shaft and a fourth push block sleeved on the fourth driving shaft and driven by the fourth driving shaft to move along the length direction of the fourth driving shaft, and the connecting rod includes a first lower connecting rod hingedly arranged between the third push block and one side of the lower expansion body, and a second lower connecting rod hingedly arranged between the fourth push block and the other side of the lower expansion body.

[0018] Furthermore, the first drive shaft and the third drive shaft are the same drive shaft, the first push block and the third push block are the same push block, the second drive shaft and the fourth drive shaft are the same drive shaft, and the second push block and the fourth push block are the same push block.

[0019] Furthermore, a pair of rear drive shaft mounting holes for respectively threadedly connecting the rear ends of the first drive shaft and the second drive shaft are provided in parallel at the rear portion of the fusion device main frame, and a pair of front drive shaft mounting holes for respectively slidingly connecting the front ends of the first drive shaft and the second drive shaft are provided in parallel at the front portion of the fusion device main frame. A push block step is fixedly provided on each drive shaft, and the push blocks on each drive shaft are located in front of or behind the push block step.

[0020] Furthermore, the number of the push blocks and the number of the push block steps on the first drive shaft are both two and are located at the front and rear of the first drive shaft respectively;

[0021] The number of the push blocks and the number of the push block steps on the second drive shaft are both two and are located at the front and rear of the second drive shaft respectively.

[0022] Furthermore, when the expandable intervertebral fusion device is not expanded, the front end point of the expansion body is located at 1 / 2-1 / 3 of the total length of the expandable intervertebral fusion device;

[0023] And / or, the outer surface of the expansion body is provided with a slope that gradually decreases from the front end to the rear end of the fusion device main frame, and the inclination angle of the slope is 1-7 degrees;

[0024] Furthermore, the expansion body includes a solid outer frame area and a porous structure area located in the solid outer frame area.

[0025] The present invention has the following beneficial effects:

[0026] The expandable intervertebral fusion device of the present invention has two sets of expansion structures arranged side by side on the left and right sides of the expansion body in the main frame of the fusion device for respectively adjusting the expansion height of the left side or the right side of the expansion body, which can not only expand the expansion body in parallel, but also expand the left and right sides of the expansion body respectively, and can treat scoliosis of the intervertebral disc, relieve compression, restore the height and tension of the vertebral segment, restore the physiological curvature of the spine, ensure the stability of the spine, and the fusion device has good fixation and fusion, which meets clinical requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the expandable intervertebral fusion cage of the present invention in a closed state, wherein (a) is a side view and (b) is a side sectional view;

[0028] Figure 2 It is a schematic structural diagram of the expandable intervertebral fusion device of the present invention in an expanded state;

[0029] Figure 3 Schematic diagram of the structure of the expandable intervertebral fusion device of the present invention in the state of the left side expanded and the right side not expanded, wherein (a) is a rear view and (b) is a rear sectional view;

[0030] Figure 4 Schematic diagram of the structure of the expandable intervertebral fusion device of the present invention in the state where the right side is expanded and the left side is not expanded, wherein (a) is a rear view and (b) is a rear sectional view;

[0031] Figure 5 It is a schematic diagram of the structure of the intervertebral fusion device of the present invention that can be expanded with the left and right sides expanded in parallel;

[0032] Figure 6 It is a schematic diagram of the internal structure of the intervertebral fusion cage that can be expanded according to the present invention;

[0033] Figure 7 It is a schematic diagram of the structure of the main frame of the intervertebral fusion cage that can be expanded in the present invention;

[0034] Figure 8 It is a schematic diagram of the structure of the expansion body in the expandable intervertebral fusion cage of the present invention;

[0035] Fig. 9 It is a schematic diagram of the structure of the drive shaft in the intervertebral fusion device that can be expanded according to the present invention;

[0036] Fig.10 It is a schematic diagram of the structure of the push block in the intervertebral fusion cage that can be expanded according to the present invention;

[0037] Fig.11 It is a schematic diagram of the structure of the connecting rod in the intervertebral fusion device that can be expanded according to the present invention;

[0038] Fig.12 It is a schematic diagram of the structure of the fixing block in the intervertebral fusion cage that can be expanded according to the present invention;

[0039] Fig.13 It is a schematic diagram of the structure of the rotating rod in the intervertebral fusion cage that can be expanded according to the present invention. DETAILED DESCRIPTION

[0040] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0041] The present invention provides an intervertebral fusion device that can be expanded. Figure 1-13 As shown, it includes a fusion device main frame 1, and a spreader 2, 2' is provided above and / or below the fusion device main frame 1. The spreader 2, 2' is provided with a porous structure or convex teeth (which can increase the bone fusion effect and prevent the fusion device from sliding or falling out). To facilitate bone grafting, a bone grafting window 25 can be provided in the middle of the spreader 2, 2', wherein:

[0042] Two sets of expansion structures are arranged side by side in the left and right sides of the fusion device main frame 1. One of the two expansion structures is connected to the left side of the expansion body 2, 2' by driving, and the other is connected to the right side of the expansion body 2, 2' by driving, so that the expansion height of the left or right side of the expansion body 2, 2' can be adjusted by the two expansion structures. At least one expansion structure includes a driving shaft 3, 3' and a push block 4, 4' sleeved on the driving shaft 3, 3' and driven by the driving shaft 3, 3' and can move along the length direction of the fusion device main frame 1. The push block Connecting rods 5, 5', 6, 6' are arranged between 4, 4' and the expansion bodies 2, 2', and the two ends of the connecting rods 5, 5', 6, 6' are hinged to the push blocks 4, 4' and the expansion bodies 2, 2' respectively (it can be understood that the directions of the hinge axes of the upper and lower ends of the connecting rods 5, 5', 6, 6' are along the width direction of the expansion bodies 2, 2', and at this time the size of the hinge hole where the hinge axis is located is preferably larger than the size of the hinge axis to form the multi-degree-of-freedom hinge structure described later, so as to realize the left and right unilateral expansion of the expansion bodies 2, 2').

[0043] When in use, the expandable intervertebral fusion cage (hereinafter referred to as "fusion cage") of the present invention is first placed in Figure 1 The fusion device is then placed in the intervertebral disc space using a holder, and the position of the fusion device in the intervertebral disc is observed using imaging equipment. The drive shaft of the left expansion structure is driven by a matching wrench, so that the push block on the drive shaft can move along the length direction of the fusion device main frame (i.e., the length direction of the drive shaft). The push block drives the connecting rod to expand the left side of the expansion body to adjust the expansion height of the left side of the expansion body. Figure 3 ; The drive shaft of the right side expansion structure is driven by the matching wrench, so that the push block on the drive shaft can move along the length direction of the main frame of the fusion device, and the push block drives the connecting rod to expand the right side of the expansion body to adjust the expansion height of the right side of the expansion body, refer to Figure 4 ; By driving the drive shafts of the two expansion structures at the same time with the matching wrench, the expansion bodies can be expanded in parallel on both sides. Figure 5 . The doctor can freely adjust the expansion height and tilt angle of the expandable intervertebral fusion device by controlling the two expansion structures, and take out the holder and the matching wrench in sequence after confirming that the position meets the needs. The expandable intervertebral fusion device of the present invention can be expanded left and right and in parallel. After the fusion device is implanted in the intervertebral disc and adjusted to the optimal position, the doctor can adjust the height and angle of the fusion device according to the situation in the intervertebral disc. The expansion force of the intervertebral implant can perfectly restore the height and tension of the vertebrae and perform intervertebral correction.

[0044] In the above structure, the push block on the drive shaft moves along the length direction of the fusion device main frame (i.e., the length direction of the drive shaft). This implementation method can be that the drive shaft does not move axially, and the push block moves axially along the drive shaft through a related matching structure with the drive shaft, such as a spiral connection structure, thereby realizing the axial movement of the push block along the fusion device main frame; or the drive shaft and the push block are axially fixed and circumferentially rotated, and the drive shaft and the main frame are connected through a related matching structure, so that the drive shaft can move axially relative to the fusion device main frame, thereby driving the push block to move axially relative to the fusion device main frame.

[0045] The expandable intervertebral fusion device of the present invention has two sets of expansion structures arranged side by side in the main frame of the fusion device for adjusting the expansion height of the left or right side of the expansion body respectively, which can not only expand the expansion body in parallel, but also expand the left and right sides of the expansion body respectively, and can treat scoliosis of the intervertebral disc, relieve compression, restore the height and tension of the vertebral segment, restore the physiological curvature of the spine, ensure the stability of the spine, and the fusion device has good fixation and fusion, which meets clinical requirements. The present invention is suitable for posterior spinal, especially lumbar fusion and fixation surgery.

[0046] In the present application, at least one of the two, between the expansion body 2, 2' and the connecting rod 5, 5', 6, 6', between the push block 4, 4' and the connecting rod 5, 5', 6, 6', is a multi-degree-of-freedom hinge structure, which enables the connecting rod 5, 5', 6, 6' to swing back and forth in the vertical direction relative to the fusion device main frame 1, and the expansion body 2, 2' to swing left and right in the vertical direction relative to the push block 4, 4'. The specific situation is as follows:

[0047] like Figure 3 and Figure 5 As shown, the expansion bodies 2, 2' and the connecting rods 5, 5', 6, 6' can be designed as a multi-degree-of-freedom hinge structure, which allows the connecting rods 5, 5', 6, 6' to swing back and forth in the vertical direction relative to the expansion bodies 2, 2', and to swing left and right in the vertical direction relative to the connecting rods 5, 5', 6, 6' (i.e. Figure 3 (b) in the rotation direction M) avoids interference between the relative motions of the two and causes the mechanism to get stuck, and makes it more convenient to expand the intervertebral fusion cage for left and right unilateral expansion.

[0048] It is conceivable that the push block and the connecting rod can also be designed as a multi-degree-of-freedom hinge structure, which allows the connecting rod to swing back and forth in the vertical direction relative to the push block, and to swing left and right in the vertical direction relative to the push block, thereby avoiding interference between the relative movements of the two and causing the mechanism to get stuck, making it more convenient to expand the intervertebral fusion device for unilateral expansion to the left and right.

[0049] In order to form a multi-degree-of-freedom hinge structure between the expansion body and the connecting rod, the present invention can have the following structural forms:

[0050] Structural form 1: Figure 1-2 and Figure 5 As shown, the side of the expansion body 2, 2' can be fixed with a rotating shaft 8, 8' extending along the length direction thereof, and the rotating shaft 8, 8' is rotatably equipped with a hinge block 7, 7', and the upper end of the connecting rod 5, 5', 6, 6' is hinged to the hinge block 7, 7', so that a multi-degree-of-freedom hinge structure is formed between the expansion body 2, 2' and the connecting rod 5, 5', 6, 6', so that the expansion body 2, 2' is not directly connected through the connecting rod 5, 5', 6, 6', but the connecting rod 5, 5', 6, 6' is indirectly connected to the expansion body 2, 2' through the hinge block 7, 7', and the expansion body 2, 2' is expanded on one side (that is, along the expansion body 2, Figure 3 When the opening body 2 and 2' move in the direction of the arrow N in (b), the left and right sides of the opening body 2 and 2' can be tilted and rotated around the hinge blocks 7 and 7' (such as Figure 3 As shown by the arrow M in (b), the relative motion of the two is prevented from interfering with each other and causing the mechanism to get stuck, and the intervertebral fusion cage can be more conveniently expanded to perform unilateral expansion on the left and right sides.

[0051] Structural form II (not shown): The side of the expansion body is rotatably equipped with a rotating shaft extending along its length direction, and a hinge block is fixed on the rotating shaft. The upper end of the connecting rod is hinged to the hinge block, so that a multi-degree-of-freedom hinge structure is formed between the expansion body and the connecting rod;

[0052] Structural form three (not shown): The upper end of the connecting rod and the side surface of the expansion body are ball-jointed.

[0053] The multi-degree-of-freedom hinge between the push block and the connecting rod can refer to the multi-degree-of-freedom hinge between the expansion body and the connecting rod, which will not be repeated here.

[0054] In the embodiments shown in the structural form 1 and the structural form 2, as shown in FIG. Figure 5 and Figure 8 As shown, in order to conveniently accommodate the hinge blocks 7, 7', the side of the expansion body 2, 2' can be provided with grooves 21, 21', and the hinge blocks 7, 7' are located at the grooves 21, 21'. In the embodiment shown in the figure, the expansion body 2, 2' is provided with a shaft channel 24 extending along the length direction of the expansion body 2, 2' and connecting the grooves 21, 21', and the shaft 8, 8' is inserted in the shaft channel 24.

[0055] like Figure 1 and Figure 8 As shown, the grooves 21, 21' are preferably slots that penetrate along the width direction of the expansion body 2, 2'. The top surfaces of the grooves 21, 21' and the top surfaces of the hinge blocks 7, 7' are preferably both planes, with a preset distance L between them. When the expansion body 2, 2' is expanded to a certain extent on one side, the top surfaces of the grooves 21, 21' and the top surfaces of the hinge blocks 7, 7' will contact and limit the expansion body 2, 2' from expanding on one side. By setting different preset distances L, the maximum expansion angle of the expansion body 2, 2' on one side can be changed.

[0056] exist Figure 1-6 In the illustrated embodiment, the expansion body comprises an upper expansion body 2 located above the fusion device main frame 1 and a lower expansion body 2' located below the fusion device main frame 1, wherein:

[0057] Corresponding to the upper support body 2, one of the two sets of support structures arranged in parallel may include a first drive shaft 3 and a first push block 4 sleeved on the first drive shaft 3 and driven by the first drive shaft 3 to move along the length direction of the first drive shaft 3, and the other set of support structures includes a second drive shaft 3' and a second push block 4' sleeved on the second drive shaft 3' and driven by the second drive shaft 3' to move along the length direction of the second drive shaft 3', and the connecting rod includes a hinged connection between the first push block 4 and one side of the upper support body 2 (it can be understood that It is understood that when there is a hinge block 7 on the upper opening body 2, one side of the upper opening body 2 refers to the hinge block 7, and the first upper connecting rod 5 and the second upper connecting rod 6 are hinged on the hinge block; when there is no hinge block on the upper opening body 2, one side of the upper opening body 2 refers to the side of the upper opening body 2, and the first upper connecting rod 5 and the second upper connecting rod 6 are hinged on the side of the upper opening body 2; similar descriptions below are all of this meaning and will not be repeated) and the second upper connecting rod 6 hingedly arranged between the second push block 4' and the other side of the upper opening body 2;

[0058] Corresponding to the lower support body 2', one of the two sets of support structures arranged in parallel includes a third driving shaft and a third push block sleeved on the third driving shaft and driven by the third driving shaft to move along the length direction of the third driving shaft, and the other set of support structures includes a fourth driving shaft and a fourth push block sleeved on the fourth driving shaft and driven by the fourth driving shaft to move along the length direction of the fourth driving shaft, and the connecting rod includes a first lower connecting rod 5' hingedly arranged between the third push block and one side of the lower support body 2', and a second lower connecting rod 6' hingedly arranged between the fourth push block and the other side of the lower support body 2'.

[0059] When in use, the first driving shaft 3 is driven by the matching wrench, so that the first push block 4 can move along the length direction of the first driving shaft 3, and the first push block 4 drives the first upper connecting rod 5 to open the left side of the upper opening body 2; the second driving shaft 3' is driven by the matching wrench, so that the second push block 4' can move along the length direction of the second driving shaft 3', and the second push block 4' drives the second upper connecting rod 6 to open the right side of the upper opening body 2; the third driving shaft is driven by the matching wrench, so that the third push block can move along the length direction of the third driving shaft, and the third push block drives the first lower connecting rod 5' to open the left side of the lower opening body 2'; the fourth driving shaft is driven by the matching wrench, so that the fourth push block can move along the length direction of the fourth driving shaft, and the fourth push block drives the second lower connecting rod 6' to open the right side of the lower opening body 2'.

[0060] It can be imagined that if the fusion device only needs to be expanded on one side, upper or lower, then only the upper expansion body 2 or only the lower expansion body 2' can be set. If the upper expansion body 2' is expanded, then only the first drive shaft 3, the second drive shaft 3', the first push block 4 and the second push block 4' need to be set accordingly. If the lower expansion body 2' is expanded, then only the third drive shaft, the fourth drive shaft, the third push block and the fourth push block need to be set accordingly.

[0061] It is also conceivable that when Figure 1-6 In the embodiment shown in the figure, when the upper expansion body 2 and the lower expansion body 2' are provided at the same time, in order to reduce the volume of the entire fusion device, the expansion structures on the same side can share the same drive shaft and the same push block, that is, the first drive shaft 3 and the third drive shaft are the same drive shaft, the first push block 4 and the third push block are the same push block, the second drive shaft 3' and the fourth drive shaft are the same drive shaft, and the second push block 4' and the fourth push block are the same push block.

[0062] When in use, the first drive shaft 3 is driven by the matching wrench, so that the first push block 4 can move along the length direction of the first drive shaft 3, and the first push block 4 simultaneously drives the first upper connecting rod 5 and the first lower connecting rod 5' to respectively open the left sides of the upper opening body 2 and the lower opening body 2'. Figure 3 By driving the second drive shaft 3 'through the matching wrench, the second push block 4 'can move along the length direction of the second drive shaft 3 ', the second push block 4 'simultaneously drives the second upper connecting rod 6 and the second lower connecting rod 6 'respectively open the upper and lower support bodies 2 'on the right side, such as Figure 4 By simultaneously driving the first drive shaft 3 and the second drive shaft 3 'through the matching wrench, the upper and lower support bodies 2 and 2' can be opened in parallel, such as Figure 5 shown.

[0063] In the embodiment shown in the figure, in order to facilitate the driving shaft to drive the push block to move forward and backward, various structural forms that can be easily thought of by those skilled in the art can be adopted. However, in order to accurately adjust the distance that the push block moves forward and backward, the present invention preferably adopts the following structural form:

[0064] like Figure 6-7 and Fig. 9As shown, a pair of rear drive shaft mounting holes 11, 11' (i.e., threaded holes) are arranged in parallel at the rear of the main frame 1 of the fusion device for respectively threading the rear ends of the first drive shaft 3 and the second drive shaft 3', and a pair of front drive shaft mounting holes 12, 12' (i.e., light holes) are arranged in parallel at the front of the main frame 1 of the fusion device for respectively slidingly connecting the front ends of the first drive shaft 3 and the second drive shaft 3', and push block steps 31, 31' are fixedly arranged on each drive shaft (i.e., the first drive shaft 3 and the second drive shaft 3'), and the push blocks 4, 4' on each drive shaft are located in front of or behind the push block steps 31, 31'. In the embodiment shown in the figure, the push blocks 4, 4' are located in front of the push block steps 31, 31', and the rear ends of the drive shafts 3, 3' are provided with a driving portion, which can be specifically a hexagonal hole 32. At this time, the driving shaft 3, 3' is driven to rotate by inserting a matching wrench into the hexagonal hole 32 at the rear end of the driving shaft 3, 3', and the driving shaft 3, 3' moves forward in the rear mounting holes 11, 11' and the front mounting holes 12, 12' of the driving shaft. The push block steps 31, 31' on the driving shaft 3, 3' push the push blocks 4, 4' to move forward, thereby expanding the expansion bodies 2, 2'. The doctor can accurately adjust the expansion height and inclination angle of the expandable intervertebral fusion device by controlling the movement of the driving shafts 3, 3'.

[0065] In order to stably open the upper opening body 2 and the lower opening body 2', the number of push blocks 4 and the number of push block steps 31 on the first drive shaft 3 are preferably two and are respectively located at the front and rear of the first drive shaft 3; the number of push blocks 4' and the number of push block steps 31' on the second drive shaft 3' are also preferably two and are respectively located at the front and rear of the second drive shaft 3'.

[0066] The hinges at both ends of the connecting rod can be designed according to conventional techniques in the art, for example, Figure 10-12 In the illustrated embodiment, a connecting rod hinge shaft 41 is provided on the side of the push blocks 4, 4', a drive shaft connecting hole 42 for the drive shaft 3, 3' to pass through is provided on the push blocks 4, 4', a push block hinge hole 51 matching with the connecting rod hinge shaft 41 is provided at one end of the connecting rods 5, 5', 6, 6', a pin hinge hole 71 and a rotating hole 72 for the rotating shaft 8, 8' to pass through are provided on the hinge blocks 7, 7', and a hinge block hinge shaft 52 matching with the pin hinge hole 71 is provided on the other end of the connecting rods 5, 5', 6, 6'.

[0067] like Figure 7 As shown, in order to facilitate the implantation of the expandable intervertebral fusion device, the head of the fusion device main frame 1 is preferably in a bullet shape. In order to facilitate the holder to clamp the fusion device, a pair of holder slots 13 can be provided on both sides of the rear part of the fusion device main frame 1.

[0068] like Figure 1-2As shown, the outer surface of the expansion body 2, 2' can be provided with a slope 23 which gradually decreases from the front end to the rear end of the fusion device main frame 1, and the inclination angle of the slope 23 is 1-7 degrees; when the expandable intervertebral fusion device is not expanded, the front end point of the expansion body 2, 2' is preferably located at 1 / 2-1 / 3 of the total length of the expandable intervertebral fusion device, which is more in line with the physiological angle between the vertebrae, and after the expansion body 2, 2' is expanded, the physiological lordosis can be ideally restored, and the physiological curvature of the spine can be restored.

[0069] In the present invention, the porous structure or convex teeth provided on the expansion body 2, 2' can form an uneven structure on the surface of the expansion body. The pores of the porous structure and the gaps between the convex teeth can provide space for bone growth and facilitate bone fusion. In addition, these structures increase the roughness of the surface of the expansion body 2, 2', thereby increasing the friction between the expansion body 2, 2' and the vertebrae, thereby preventing the fusion device from shaking and slipping.

[0070] Wherein, when a porous structure is provided on the support body 2, 2', the porosity of the porous structure is preferably 40-90%. The pore size of the porous structure is preferably 300-600 μm, at which the effect is best, and the bone fusion rate of the implant is improved. In order to ensure the overall strength of the support body 2, 2', the support body 2, 2' preferably includes a solid outer frame area and a porous structure area located within the solid outer frame area. The support body 2, 2' is preferably manufactured by 3D printing, or formed by processes such as pickling, so that a porous structure is formed on the surface of the support body to facilitate fusion with the bone. The material of the support body 2, 2' is preferably a variety of materials such as titanium alloy, tantalum, or niobium zirconium alloy.

[0071] When the opening body is provided with a convex tooth, the convex tooth is as follows Figure 8 As shown, in order to increase the firmness of the expandable intervertebral fusion device, the outer surface of the expander body 2, 2' can be provided with transverse anti-retraction teeth 22, and the transverse anti-retraction teeth 22 can also be inclined toward the rear end direction of the fusion device main frame 1 to facilitate the implantation of the fusion device. In addition, the structure of the protruding teeth can also be spaced, discontinuous, and single protrusions.

[0072] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A expandable intervertebral fusion cage, characterized in that: It comprises a fusion device main frame, and a spreading body is provided above and / or below the fusion device main frame, and the spreading body is provided with a porous structure or convex teeth, wherein: Two sets of expansion structures are arranged side by side in the left and right sides of the main frame of the fusion device, one of the two expansion structures is connected to the left side of the expansion body by driving, and the other is connected to the right side of the expansion body by driving, so that the expansion height of the left side or the right side of the expansion body can be adjusted respectively by the two expansion structures, at least one of the expansion structures includes a driving shaft and a push block sleeved on the driving shaft and connected by the driving shaft to move along the length direction of the main frame of the fusion device, a connecting rod is arranged between the pushing block and the expansion body, and the two ends of the connecting rod are respectively hinged to the pushing block and the expansion body; A multi-degree-of-freedom hinge structure is formed between the expansion body and the connecting rod, and the multi-degree-of-freedom hinge structure enables the connecting rod to swing forward and backward relative to the expansion body in the vertical direction, and enables the expansion body to swing left and right relative to the connecting rod in the vertical direction; A rotating shaft extending along the length direction is fixedly provided on the side of the support body, and a hinge block is rotatably mounted on the rotating shaft, and the upper end of the connecting rod is hinged to the hinge block, so that the multi-degree-of-freedom hinged structure is formed between the support body and the connecting rod; or, a rotating shaft extending along the length direction is rotatably mounted on the side of the support body, and a hinge block is fixedly mounted on the rotating shaft, and the upper end of the connecting rod is hinged to the hinge block, so that the multi-degree-of-freedom hinged structure is formed between the support body and the connecting rod.

2. The expandable intervertebral fusion cage according to claim 1, characterized in that: A groove is provided on the side of the expansion body, and the hinge block is located in the groove; The top surface of the groove and the top surface of the hinge block are both planes, and there is a preset distance between the two. When the expansion body is expanded to a certain extent on one side, the top surface of the groove and the top surface of the hinge block will contact and limit the expansion of the expansion body on one side. By setting different preset distances, the maximum expansion angle of the expansion body on one side can be changed.

3. The expandable intervertebral fusion cage according to claim 1 or 2, characterized in that: The expansion body comprises an upper expansion body located above the main frame of the fusion device, wherein one expansion structure comprises a first driving shaft and a first push block sleeved on the first driving shaft and connected by the first driving shaft to be movable along the length direction of the first driving shaft, and another expansion structure comprises a second driving shaft and a second push block sleeved on the second driving shaft and connected by the second driving shaft to be movable along the length direction of the second driving shaft, and the connecting rod comprises a first upper connecting rod hingedly arranged between the first pushing block and one side of the upper expansion body, and a second upper connecting rod hingedly arranged between the second pushing block and the other side of the upper expansion body; And / or, the expansion body includes a lower expansion body located below the fusion device main body frame, wherein one expansion structure includes a third driving shaft and a third push block sleeved on the third driving shaft and driven by the third driving shaft to move along the length direction of the third driving shaft, and the other expansion structure includes a fourth driving shaft and a fourth push block sleeved on the fourth driving shaft and driven by the fourth driving shaft to move along the length direction of the fourth driving shaft, and the connecting rod includes a first lower connecting rod hingedly arranged between the third push block and one side of the lower expansion body, and a second lower connecting rod hingedly arranged between the fourth push block and the other side of the lower expansion body.

4. The expandable intervertebral fusion cage according to claim 3, characterized in that: The first drive shaft and the third drive shaft are the same drive shaft, the first push block and the third push block are the same push block, the second drive shaft and the fourth drive shaft are the same drive shaft, and the second push block and the fourth push block are the same push block.

5. The expandable intervertebral fusion cage according to claim 4, characterized in that: A pair of rear drive shaft mounting holes for respectively threadedly connecting the rear ends of the first drive shaft and the second drive shaft are arranged in parallel at the rear portion of the fusion device main body frame, and a pair of front drive shaft mounting holes for respectively slidingly connecting the front ends of the first drive shaft and the second drive shaft are arranged in parallel at the front portion of the fusion device main body frame, and a push block step is fixedly provided on each drive shaft, and the push blocks on each drive shaft are located in front of or behind the push block step.

6. The expandable intervertebral fusion cage according to claim 5, characterized in that: The number of push blocks and the number of push block steps on the first drive shaft are both two and are located at the front and rear of the first drive shaft respectively; The number of the push blocks and the number of the push block steps on the second drive shaft are both two and are located at the front and rear of the second drive shaft respectively.

7. The expandable intervertebral fusion cage according to claim 6, characterized in that: When the expandable intervertebral fusion device is not expanded, the front end point of the expansion body is located at 1 / 2-1 / 3 of the total length of the expandable intervertebral fusion device; And / or, the outer surface of the expansion body is provided with a slope that gradually decreases from the front end to the rear end of the fusion device main frame, and the inclination angle of the slope is 1-7 degrees.

8. The expandable intervertebral fusion cage according to claim 7, characterized in that: The expansion body comprises a solid outer frame area and a porous structure area located in the solid outer frame area.

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