A fusion device

Abstract

The application belongs to the technical field of medical devices, and particularly relates to a fusion device, which comprises a driving assembly, a deformation part connected with the driving part, the driving part moves between a first position and a second position, and the deformation part deforms under the driving of the driving part; when the driving part is located at the first position, the deformation part is in a contraction state and close to a central shaft; when the driving part is located at the second position, the deformation part is in an opening state and away from the central shaft; an inner shell is sleeved outside the driving assembly, the inner shell comprises a plurality of separable expandable bodies, the adjacent expandable bodies are elastically connected, when the deformation part is in the contraction state, the expandable bodies are close to the central shaft, and when the deformation part is in the opening state, the expandable bodies are pushed away from the central shaft; an outer shell is sleeved outside the inner shell, the outer shell is made of a memory alloy, and when entering a to-be-inserted position, the outer shell is in an opening state, and the inner shell is driven to the opening state by the driving assembly to support the outer shell to be stable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and in particular relates to a fusion cage. BACKGROUND

[0002] Lumbar interbody fusion can effectively treat lumbar degeneration and instability, and it can fuse the upper and lower vertebral bodies, maintain the intervertebral space height, reduce the nerve root pressure, and maintain the stability of the spine.

[0003] In the prior art, the conventional fusion cage can effectively guarantee the intervertebral space height and reduce the compression symptoms caused by the vertebral body, but there are problems such as poor bone grafting effect, low bone fusion rate, and unsatisfactory recovery of the physiological lordosis of the vertebral body after the vertebral body fusion. In addition, the expansion in the height direction means that the size in the height direction can be reduced to a certain extent to reduce the incision, and in order to further reduce the surgical incision, the size in the width direction is also reduced to meet the surgical requirements and reduce the surgical trauma. SUMMARY

[0004] The present application is proposed based on the above-mentioned needs in the prior art, and the technical problem to be solved by the present application is to provide a fusion cage to reduce surgical trauma and facilitate surgical operation.

[0005] In order to solve the above-mentioned problems, the technical scheme provided by the present application comprises:

[0006] A fusion cage is provided, comprising: a driving assembly comprising a driving part and a deformation part connected with the driving part, the driving part moving between a first position and a second position, and the deformation part deforming under the driving of the driving part; when the driving part is located at the first position, the deformation part is in a contracted state and the deformation part is close to the central axis; when the driving part is located at the second position, the deformation part is in an open state and the deformation part is away from the central axis; an inner shell is sleeved outside the driving assembly, the inner shell comprising a plurality of separable expandable bodies, the adjacent expandable bodies being elastically connected, the expandable bodies being close to the central axis when the deformation part is in the contracted state, and the expandable bodies being pushed away from the central axis when the deformation part is in the open state; an outer shell is sleeved outside the inner shell, the outer shell being made of a memory alloy, the outer shell being in an open state when entering a position to be inserted, and the inner shell being driven by the driving assembly to be in the open state to support the outer shell to remain stable.

[0007] The fusion device can be kept in a minimum volume state before being implanted in the body to reduce the size of the surgical opening and reduce trauma, and after being inserted into the intervertebral space, the deformation part can be driven to an open state by adjusting the driving part to support the expandable body to open, and then support the shell to be attached to the endplate of the superior vertebral body to complete fusion. Since the size of the fusion device is adjustable, the opening degree of the fusion device can be adjusted according to the insertion position to adapt to the insertion environment. In addition, it is also convenient for secondary surgery and revision.

[0008] Preferably, the driving part comprises a first rod and a moving piece, the first rod is provided with a first thread outside, the moving piece is sleeved outside the first rod, the moving piece is provided with a second thread inside, and the first thread and the second thread are matched; the deformation part is sleeved on the first rod, and the bottom of the deformation part is connected with the top of the moving piece.

[0009] Through the above arrangement, when the moving piece moves on the first rod, the deformation part can be driven to deform to change its state.

[0010] Preferably, the deformation part comprises a linkage assembly, the linkage assembly comprises a first connecting piece and a second connecting piece, the first connecting piece has a first end and a second end at two ends respectively, the second connecting piece has a third end and a fourth end at two ends respectively, the first end is pivotally connected to the lower part of the deformation part, the second end and the third end are pivotally connected, and the fourth end is pivotally connected to one end of the first rod away from the driving part; when the driving part moves towards the direction where the deformation part is located, the included angle between the first connecting piece and the second connecting piece gradually decreases, and the connection between the second end and the third end moves away from the central axis.

[0011] Preferably, the deformation part further comprises a support, the support is arranged at the connection between the second end and the third end, and the support is matched with the inner side wall of the inner shell.

[0012] Through the above arrangement, the contact area between the deformation part and the expandable body is increased, so that the expansion is facilitated and labor is saved.

[0013] Preferably, the expandable body comprises a first connecting end and a second connecting end, the first connecting ends of two adjacent expandable bodies are connected by an elastic member, and the second connecting ends of two adjacent expandable bodies are connected by an elastic member, so as to provide the freedom of the expandable body to approach and / or move away from the central axis.

[0014] Through the above arrangement, the freedom of the expandable body is provided, so that the size of the fusion device is scaled.

[0015] Preferably, the inner side wall of the expandable body is provided with a first groove, the first groove is matched with the support, and when the deformation part is in an open state, the support abuts against the inner wall of the first groove.

[0016] Preferably, the driving part comprises a fixing part, which is fixedly arranged at the bottom of the first rod.

[0017] By the above arrangement, the first rod is kept fixed by the fixing part when the size of the interbody fusion cage is adjusted, and the moving part is rotated to adjust the expansion degree of the expandable part.

[0018] Preferably, the outer wall of the shell is provided with a plurality of second grooves along the length direction.

[0019] By the above arrangement, the stress distribution on the endplate surface after the interbody fusion cage is implanted is improved, which is helpful for fusion.

[0020] Preferably, the shell comprises connecting parts and supporting parts, the connecting parts connect two adjacent supporting parts, and the connecting parts change between a stretched state and a contracted state according to the change of the environment; when the shell is located at the position to be inserted, the connecting parts are in the stretched state.

[0021] By the above arrangement, the shell is zoomed.

[0022] Preferably, the upper end of the shell is a cone, and the rear end is a cylinder.

[0023] By the above arrangement, the interbody fusion cage is conveniently inserted into the intervertebral space and has good supporting force.

[0024] Compared with the prior art, the driving part of the present application drives the deformation part to deform.

[0025] By the above arrangement, the interbody fusion cage can be expanded and contracted in four directions, so that the volume can be kept to be minimum before being implanted into the body, so as to reduce the size of the surgical opening and reduce the trauma, and after being inserted into the intervertebral space, the driving part can be adjusted to drive the deformation part to be in the open state, so as to support the expansion of the expandable part, and then support the shell to be attached to the endplate of the upper vertebral body to complete the fusion. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some of the embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings.

[0027] Figure 1 Fig. 1 is a structural schematic diagram of a fusion device in an open state according to an embodiment of the present application;

[0028] Figure 2 Fig. 2 is a structural schematic diagram of a fusion device driving assembly in a certain state according to an embodiment of the present application;

[0029] Figure 3 Fig. 3 is a structural schematic diagram of a fusion device driving assembly in another state according to an embodiment of the present application;

[0030] Figure 4 Fig. 4 is a structural schematic diagram of a fusion device according to an embodiment of the present application;

[0031] Figure 5 Fig. 5 is a structural schematic diagram of an inner shell and internal structure according to an embodiment of the present application;

[0032] Figure 6 Fig. 6 is a structural schematic diagram of an inner shell and internal structure from another angle according to an embodiment of the present application;

[0033] Figure 7 Fig. 7 is a structural schematic diagram of a fusion device in a contracted state according to an embodiment of the present application.

[0034] Reference signs:

[0035] 1, first rod; 2, moving piece; 3, fixed piece; 4, base; 5, connecting rod assembly; 6, support piece; 7, top base; 8, first connecting piece; 9, second connecting piece; 10, expandable body; 11, first groove; 12, first connecting end; 13, second connecting end; 14, outer shell; 15, second groove; 16, inner shell; 17, driving assembly; 18, connecting part; 19, support part. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0037] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be fixedly connected, or detachably connected, or integrally connected, which can be mechanically connected, or electrically connected, which can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above-mentioned term in the present application can be understood according to the specific circumstances.

[0038] The terms "top", "bottom", "above", "under" and "on" used throughout the description are relative positions of components of the device, for example, the relative positions of the top and bottom substrates inside the device. It can be understood that the device is multifunctional, regardless of their orientation in space.

[0039] In order to facilitate the understanding of the embodiments of the present application, the following will be further explained and described with specific embodiments in conjunction with the accompanying drawings, and the embodiments do not constitute limitations on the embodiments of the present application.

[0040] The present embodiment provides a fusion device, as shown in Figures 1-7 .

[0041] The fusion device comprises a driving assembly 17, an inner shell 16 and an outer shell 14.

[0042] The driving assembly 17 comprises a driving part and a deformation part, the driving part can move between a first position and a second position under external force, and the deformation part is deformed under the driving of the driving part, and the deformation part will be in different states or transform between states when the driving part is in different positions or during movement. The driving assembly 17 uses TC4 material.

[0043] The driving part, as shown in Figure 2 and Figure 3 , comprises a first rod 1, a moving part 2 and a fixed part 3.

[0044] The first rod 1 is provided with a first thread on the outer side wall, the moving part 2 is sleeved on the first rod 1, and the inner side wall of the moving part 2 is provided with a second thread, the first thread and the second thread are matched, so that the moving part 2 moves on the first rod 1 by rotating and can stop at any place. The fixed part 3 is arranged at the bottom of the first rod 1 and fixed with the first rod 1, and the fixed part 3 is provided with a third groove matched with the bottom of the first rod 1, so that the bottom of the first rod 1 is fixed in the fixed part 3. Such arrangement limits the movement of the moving part 2 and prevents the moving part 2 from rotating out of the first rod 1, while it can keep the fixed state of the first rod 1 as a clamping fulcrum when the fusion device is implanted in the body. At this time, rotating the moving part 2 can change the position to push the deformation part to change its state.

[0045] The deformation part is sleeved on the first rod 1. The deformation part comprises a base 4, a connecting rod assembly 5, a support 6 and a top base 7.

[0046] The base 4 is sleeved on the first rod 1 and located at the bottom of the deformation part. The base 4 is in contact with the moving part 2. When the moving part 2 moves on the first rod 1 by rotating, the base 4 also moves.

[0047] The top base 7 is fixedly arranged at the top of the first rod 1.

[0048] The connecting rod assembly 5 comprises a first connecting piece 8 and a second connecting piece 9. The first connecting piece 8 comprises a first end and a second end, the second connecting piece 9 comprises a third end and a fourth end, the first end is pivotally connected with the base 4, the fourth end is pivotally connected with the top base 7, and the second end and the third end are pivotally connected. The second end and the third end are provided with torsion springs. In the natural state, the first connecting piece 8 and the second connecting piece 9 extend in the same direction. When the moving part 2 moves towards the top base 7, the base 4 is abutted and pushed to move towards the top base 7 by the moving part 2. Since one end of the second connecting piece 9 is fixed, the included angle between the first connecting piece 8 and the second connecting piece 9 gradually decreases, so that the connection between the second end and the third end moves away from the central axis. When the moving part 2 moves away from the top base 7, the base 4 abuts against the moving part 2 to change the natural state of the torsion springs, the included angle between the first connecting piece 8 and the second connecting piece 9 gradually increases, and the connection between the second end and the third end moves close to the central axis.

[0049] The support 6 is arranged at the connection between the second end and the third end, and the support 6 is matched with the inner side wall of the inner shell 16. For example, the support 6 is changed into a hemispherical shape.

[0050] Further, the length of the first rod 1 is approximately equal to the length of the fixed part 3, the moving part 2, the base 4 and the connecting rod assembly 5 in the natural state. When the connecting rod assembly 5 is in the natural state (i.e. the torsion springs of the second end and the third end are in the natural state), the moving part 2 is located at the first position, at this time, the deformation part is in the contracted state. When the moving part 2 moves upwards to the second position, the support 6 gradually moves outward away from the central axis until the second connecting piece 9 is perpendicular to the first rod 1.

[0051] The inner shell 16 is like Figures 4-6As shown, the inner shell 16, fitted outside the drive assembly 17, includes a plurality of separable expandable bodies, with adjacent expandable bodies elastically connected. The inner shell 16 has a groove-shaped structure adapted to the support member 6. Correspondingly, each expandable body has a first groove 11. During the opening process of the deformable section, the support member 6 abuts against the first groove 11, pushing the expandable body to move away from the central axis. During the contraction process of the deformable section, the support member 6 contracts inward, and the expandable body moves towards the central axis until the elastic connection between two adjacent expandable members 10 is in its natural state.

[0052] The expandable body includes a first connecting end 12 and a second connecting end 13. The first connecting ends 12 of two adjacent expandable bodies are connected by an elastic element, and the second connecting ends 13 are also connected by an elastic element. The elastic element provides the expandable body with the freedom to move closer to and / or away from the central axis, and the connection at both ends by an elastic element maintains the overall stability and balance of the expandable body.

[0053] Furthermore, the upper part of the inner shell 16 is cone-shaped to facilitate insertion between the upper and lower cones at the insertion position, and the lower part of the inner shell 16 is column-shaped to provide support for the upper and lower cones.

[0054] Furthermore, the expandable body is made of PEEK material.

[0055] By combining the drive assembly 17 and the inner shell 16, the opening degree of the fusion device can be adjusted according to the actual intervertebral environment. Since the moving part 2 can stop at any position of the first rod 1, the support part 6 can push the expandable body to open to any height within the limit range, thereby adjusting the height and width of the fusion device to fit the upper and lower vertebrae.

[0056] Casing 14, such as Figure 1 and Figure 7 As shown, the outer shell 14, made of shape memory alloy, is fitted over the inner shell 16 and is in an open state when inserted into the insertion position. This open state is unstable, meaning the shell itself is relatively soft and easily deformed. Therefore, internal support is needed to maintain the fusion device's support force. The inner shell 16 is driven into the open state by the drive assembly 17 to support the outer shell 14 and maintain stability. Multiple second grooves 15 are provided along the length of the outer wall of the outer shell 14, which facilitates fusion with the upper and lower vertebral endplates when the outer shell 14 is in the open state, optimizing the stress distribution on the endplate surface. The second grooves effectively prevent the fusion device from sliding after insertion into the body. Furthermore, the outer shell is made of nickel-titanium shape memory alloy.

[0057] The outer shell 14 includes a connecting part 18 and a supporting part 19. The connecting part 18 connects two adjacent supporting parts 19. The connecting part 18 changes between a stretched state and a contracted state according to the changes in the environment. When the outer shell 14 is in the insertion position, the connecting part 18 is in a stretched state, so that the outer shell 14 is in an open state.

[0058] Furthermore, the length of the outer shell 14 is approximately the same as the length of the first rod 1, so that the first rod 1 is slightly exposed or completely retracted inside the outer shell 14, further reducing the space occupied by the fusion device and avoiding interference with the body.

[0059] In one feasible implementation of this embodiment, the deformable part has four sets of first connecting members 8 and second connecting members 9, corresponding to four supporting members 6. When the base 4 moves towards the position close to the top seat 7, the four supporting members 6 can be opened in four directions: up, down, left, and right. The corresponding inner shell 16 is provided with four expandable members 10, which correspond to the four supporting members 6, so that the expandable members 10 can also be opened in four directions: up, down, left, and right, thereby supporting the outer shell 14.

[0060] In its natural state, the fusion device has the moving part 2 in the first position, the deformable part in a retracted state, the first connecting part 8 and the second connecting part 9 in the linkage assembly 5 extending in the same direction, the support part 6 close to the central axis, the multiple elastic connecting parts of the inner shell 16 in their natural state, the distance between the multiple expandable parts at its minimum, the connecting parts of the outer shell 14 in a retracted state, and the overall volume of the fusion device at its minimum. In this state, the fusion device is inserted into the body and extended to the insertion position, inserted between the upper and lower vertebrae through the upper end of the vertebral body of the outer shell 14, and supported between the two vertebrae by the lower part of the column of the outer shell 14.

[0061] After the fixing member 3 is clamped and fixed, the rotating moving member 2 moves to the second position, pushing the base 4 to move closer to the top seat 7. The supporting member 6 moves away from the central axis and abuts against the inner wall of the expandable body, pushing the expandable body to move away from the central axis. The expandable bodies move away from each other, and the outer shell 14 made of metal alloy is in an open state and is stably expanded between the upper and lower cones under the support of the inner shell 16.

[0062] During subsequent secondary surgeries, the removal and repair of the fusion device is extremely convenient. The fixing member 3 is clamped and fixed, while the moving member 2 is rotated in the opposite direction, causing the moving member 2 to move towards the first position. The base 4 moves away from the top seat 7. As the thrust on the connecting rod assembly 5 decreases and gradually becomes less than the elastic force of the torsion spring, it returns to its natural state. The corresponding support member 6 moves towards the central axis, and the expandable member 10 also moves towards the central axis, causing the inner shell 16 to contract inward. Since the supporting force of the outer shell 14 is limited, when the supporting force inside it decreases, the outer shell 14 deforms under the pressure of the upper and lower vertebrae, making it easy to remove.

[0063] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A fusion device, characterized in that, include: A drive assembly includes a drive unit and a deformation unit connected to the drive unit. The drive unit moves between a first position and a second position, and the deformation unit deforms under the drive unit's influence. When the driving part is in the first position, the deformable part is in a contracted state, close to the central axis; when the driving part is in the second position, the deformable part is in an open state, away from the central axis; the driving part includes a first rod and a moving member, the first rod has a first thread on its outer side, the moving member is sleeved on the first rod, and the moving member has a second thread inside, the first thread and the second thread being compatible; the deformable part is sleeved on the first rod, and the bottom of the deformable part is connected to the top of the moving member; the deformable part includes a connecting rod assembly, the connecting rod assembly includes a first connecting member and a second connecting member, the first... The two ends of the connector are the first end and the second end, and the two ends of the second connector are the third end and the fourth end. The first end is pivotally connected to the lower part of the deformable part, the second end and the third end are pivotally connected, and the fourth end is pivotally connected to the end of the first rod away from the drive part. When the drive part moves in the direction of the deformable part, the included angle between the first connector and the second connector gradually decreases, and the connection between the second end and the third end moves in a direction away from the central axis. The deformable part also includes a support member, which is disposed at the connection between the second end and the third end, and the support member is adapted to the inner sidewall of the inner shell. An inner shell, fitted outside the drive assembly, includes four separable expandable bodies. Adjacent expandable bodies are elastically connected. When the deformation part is in a contracted state, the expandable bodies are close to the central axis. When the deformation part is in an open state, the expandable bodies are pushed away from the central axis. Each expandable body includes a first connecting end and a second connecting end. The first connecting ends of two adjacent expandable bodies are connected by an elastic element, and the second connecting ends of two adjacent expandable bodies are connected by an elastic element to provide the expandable bodies with the freedom to move closer to and / or away from the central axis. The outer shell, which is fitted over the inner shell, is made of shape memory alloy. When it is inserted into the insertion position, the outer shell will be in an open state. The inner shell is driven to open by the drive component to support the outer shell and keep it stable.

2. The fusion device according to claim 1, characterized in that, The inner wall of the expandable part is provided with a first groove, which is adapted to the support member. When the deformable part is in the open state, the support member abuts against the inner wall of the first groove.

3. The fusion device according to claim 1, characterized in that, The drive unit includes a fixing member, which is fixedly disposed at the bottom of the first rod.

4. The fusion device according to claim 1, characterized in that, The outer wall of the outer shell is provided with a plurality of second grooves along the length direction.

5. The fusion device according to claim 1, characterized in that, The outer shell includes a connecting part and a supporting part. The connecting part connects two adjacent supporting parts. The connecting part changes between a stretched state and a contracted state according to changes in the environment. When the outer shell is in the insertion position, the connecting part is in a stretched state.

6. The fusion device according to claim 1, characterized in that, The upper end of the outer shell is conical, and the rear end is cylindrical.

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