Minimally invasive expandable spinal fusion cage

Abstract

The minimally invasive expandable spinal fusion cage comprises an outer-layer expansion tube, a column inner core is arranged in the outer-layer expansion tube, the outer-layer expansion tube is fixedly connected with one end of the column inner core, and the tube body part of the outer-layer expansion tube comprises a plurality of lantern rings arranged at intervals and expansion deformation parts connected between the adjacent lantern rings. Two folds are arranged in the middle of each expansion deformation part; after the expansion deformation part deforms, a semi-opening-shaped protrusion is formed, and the top end of the semi-opening-shaped protrusion is a supporting plane. In addition, by designing the elastic arms and arranging the limiting protrusions, a traditional snap spring structure is replaced, the installation process is simplified, and the limiting reliability is enhanced. The device has the advantage that the height of the intervertebral space can be kept.

Description

Technical Field

[0001] The invention relates to the technical field of spinal implant accessories, and in particular to a minimally invasive expandable spinal fusion device. Background Art

[0002] Spinal fusion is an important means of treating various spinal diseases, especially in cases of spinal instability, disc herniation, and spinal deformity. At present, the common spinal fusion cages on the market are usually block-shaped structures, and their original design is to promote bone healing by providing stable support. However, this type of traditional fusion cage has some inherent defects during the operation.

[0003] During spinal fusion surgery, surgeons first need to make an incision between the patient's spine in order to insert the fusion device into the intervertebral disc. Since existing fusion devices are relatively fixed in shape and volume, once there is a large anatomical variation during the insertion process, it is often difficult for doctors to successfully place them in the designated position. In addition, this fixed block structure lacks flexibility in terms of expansion and deformation, which limits the doctor's operating space and may cause additional safety hazards during surgery.

[0004] In response to this problem, the applicant has disclosed an expandable spinal fusion device (CN 105943204A), which allows doctors to accurately control the size of the expansion and deformation part according to actual conditions during the operation, thereby improving the convenience and safety of the operation to a certain extent. However, although this invention has been improved in many aspects compared with traditional fusion devices, it still has some problems that need to be solved in actual clinical use.

[0005] First, when the fusion device expands, its deformed part will form a triangular bulge. This design makes the force-bearing area mainly concentrated on the top of the bulge. In actual application, this design may cause the fusion device to sink when bearing load and eventually sink into the vertebral body. This phenomenon may not only lead to a shortening of the intervertebral disc distance (intervertebral space), but may also cause a series of adverse consequences, such as postoperative pain, functional impairment, and even affect the overall stability of the spine.

[0006] Secondly, the inner core end of the column of the fusion device is installed with a retaining spring to prevent the inner core from retracting into the outer expansion tube when subjected to force. However, this structure has certain defects. On the one hand, the installation process of the retaining spring is complicated and requires precise alignment, which increases the difficulty of the surgical operation; on the other hand, the retaining spring is prone to dislocation when subjected to external force, causing the inner core to retract unexpectedly, thereby affecting the shape recovery and function of the fusion device. This not only increases the risk of surgery, but may also lead to unsatisfactory postoperative recovery of patients.

[0007] Therefore, it is necessary to further improve and perfect the prior art to overcome these shortcomings, and the present invention is made based on this situation. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a minimally invasive expandable spinal fusion device capable of maintaining the height of the intervertebral space.

[0009] The present invention is achieved through the following technical solutions:

[0010] In order to solve the above technical problems, the present invention provides a minimally invasive expandable spinal fusion device, including an outer expansion tube, a cylindrical inner core is arranged in the outer expansion tube, one end of the outer expansion tube and the cylindrical inner core is fixedly connected, the tube body portion of the outer expansion tube includes a plurality of spaced rings and an expansion deformation portion connected between adjacent rings, each of the expansion deformation portions is provided with two folds in the middle; when the expansion deformation portion is deformed, a semi-mouth-shaped protrusion is formed, and the top of the semi-mouth-shaped protrusion is a supporting plane.

[0011] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, two or more expansion deformation parts are provided between adjacent rings, and each expansion deformation part is evenly and symmetrically distributed on the upper and lower sides of the outer expansion tube.

[0012] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, the expansion deformation parts between adjacent rings are staggered with each other in the circumferential direction.

[0013] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, a center hole is provided at the end of the movable end of the inner core of the column, a plurality of slots are provided on the side wall of the center hole, the slots separate the end of the inner core of the column into a plurality of elastic arms, and a hook-shaped limiting protrusion is provided on the outer side wall of the free end of the elastic arm;

[0014] Before the outer expansion tube is deformed, the inner core of the column is shorter than the outer expansion tube and is completely located inside the outer expansion tube; when the outer expansion tube is deformed, the limiting protrusion extends from the outer expansion tube and deforms outward, thereby blocking the movable end of the outer expansion tube.

[0015] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, a connecting hole with an internal thread is provided at the bottom of the central hole.

[0016] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, the length L of each expansion deformation part decreases successively along the axial direction, so that the height H of the protrusion of each expansion deformation part after deformation decreases gradually.

[0017] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, the outer wall of the inner core of the column is in close contact with the inner wall of the outer expansion tube.

[0018] In order to further solve the technical problem to be solved by the present invention, in a minimally invasive expandable spinal fusion device provided by the present invention, a slot is provided at the end of the movable end of the outer expansion tube.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The main innovation of the present invention is that an expansion deformation portion with two folds is used to form a semi-mouth-shaped protrusion to increase the force-bearing area and evenly distribute the pressure, thereby effectively maintaining the distance between the intervertebral discs and preventing the fusion device from sinking.

[0021] In addition, by designing elastic arms and setting limit protrusions, the traditional spring structure is replaced, simplifying the installation process and enhancing the reliability of the limit. These innovations significantly improve the stability and safety of the spinal fusion cage, optimize the convenience of surgical operations, and ultimately improve the patient's postoperative recovery and quality of life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 It is an exploded schematic diagram of the present invention;

[0024] Figure 2 yes Figure 1 A partial enlarged schematic diagram in the middle;

[0025] Figure 3 It is a schematic diagram of the three-dimensional structure after deformation of the present invention;

[0026] Figure 4 It is a left side view after deformation of the present invention;

[0027] Figure 5 yes Figure 4 Cross-sectional view at BB in the middle. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] like Figures 1 to 5 As shown, this embodiment provides a minimally invasive expandable spinal fusion device, which is designed to be implanted into the patient's intervertebral disc through the force applying device disclosed in CN105943205A. After the fusion device is implanted, it is supported between the upper and lower vertebrae to provide the necessary stability to promote the healing and functional recovery of the intervertebral disc.

[0030] The structure of the fusion device mainly includes an outer expansion tube 1 and a column inner core 2. The column inner core 2 is located in the inner cavity of the outer expansion tube 1, and one end (the end is a fixed end, and the other end is a movable end) of the two is fixedly connected.

[0031] The body of the outer expansion tube 1 uses a number of spaced rings 11, and the expansion deformation parts 12 are connected between these rings 11. Two folds 121 are provided in the middle of each expansion deformation part 12. This innovative design enables a half-mouth-shaped protrusion 122 to be formed when the expansion deformation part 12 is deformed. The top of this half-mouth-shaped protrusion 122 is a support plane 123. The support plane 123 is a flat shape rather than a pointed shape, thereby increasing the force-bearing area and facilitating the uniform distribution of the pressure. This design can effectively maintain the intervertebral disc distance (intervertebral space), help prevent the fusion device from sinking, and ensure the therapeutic effect of the operation.

[0032] In order to further enhance the stability of the structure, two or more expansion deformation parts 12 are provided between adjacent collars 11, and these expansion deformation parts 12 are evenly and symmetrically distributed on the upper and lower sides of the outer expansion tube 1. This symmetrical design enables the fusion device to be evenly distributed when subjected to force, avoiding structural damage or deformation caused by uneven force.

[0033] In addition, the expansion deformation portions 12 between adjacent collars 11 are staggered in the circumferential direction, which further enhances the balance of support, makes each support point evenly stressed, and reduces the risk of deformation under dynamic load.

[0034] Another major innovation of the present invention is that the limiting protrusion 221 at the free end of the elastic arm 22 is used to replace the retaining spring. Specifically, a central hole 21 is provided at the movable end of the column inner core 2, and a plurality of slots 211 are provided on the hole wall of the central hole 21. These slots 211 separate the end of the column inner core 2 into a plurality of elastic arms 22, thereby significantly improving the elastic deformation capacity of the elastic arm 22. A hook-shaped limiting protrusion 221 is provided on the outer side wall of the free end of the elastic arm 22. This design replaces the retaining spring structure in the traditional invention patent CN105943204A.

[0035] Specifically, when the outer expansion tube 1 is not deformed, the length of the column core 2 is shorter than the outer expansion tube 1 and is completely located inside the outer expansion tube 1. As the outer expansion tube 1 is deformed, the limiting protrusion 221 will extend from the outer expansion tube 1 and deform outward, playing the role of blocking the movable end of the outer expansion tube 1. The limiting protrusion 221 has a simple structure, which not only simplifies the installation steps and avoids the cumbersome installation of the retaining spring, but also significantly enhances the reliability of the limit and reduces the risk caused by the retaining spring coming out.

[0036] Furthermore, a connecting hole 23 with an internal thread is provided at the bottom of the central hole 21. The connecting hole 23 can be connected to the force applying device disclosed in CN105943205A.

[0037] Furthermore, the length L of each expansion deformation part 12 decreases in the axial direction, so that the height H of each expansion deformation part 12 after deformation decreases. The beneficial effect of this shape is to adapt to the rectangular space between human vertebrae, facilitate the implementation of surgery, and facilitate the rehabilitation treatment of patients.

[0038] Furthermore, the outer wall of the inner core 2 of the column is in close contact with the inner wall of the outer expansion tube 1. This can prevent the expansion deformation portion 12 from deforming inwardly of the tube and improve the accuracy of the deformation.

[0039] Furthermore, a slot 13 is provided at the end of the movable end of the outer expansion tube 1, and the slot 13 facilitates quick connection and positioning with the force applying device disclosed in CN105943205A.

[0040] In summary, the minimally invasive expandable spinal fusion device of this embodiment provides a safer, more effective and easier-to-operate spinal fusion solution through a number of innovative designs, which can significantly improve the patient's recovery effect and quality of life after surgery.

Claims

1. A minimally invasive expandable spinal fusion device, characterized in that: The invention comprises an outer expansion tube (1), wherein a column inner core (2) is arranged inside the outer expansion tube (1), and one end of the outer expansion tube (1) and the column inner core (2) are fixedly connected, and the tube body of the outer expansion tube (1) comprises a plurality of spaced-apart rings (11) and an expansion deformation portion (12) connected between adjacent rings (11), and each expansion deformation portion (12) is provided with two folds (121) in the middle; when the expansion deformation portion (12) is deformed, a semi-mouth-shaped protrusion (122) is formed, and the top end of the semi-mouth-shaped protrusion (122) is a supporting plane (123).

2. The minimally invasive expandable spinal fusion device according to claim 1, characterized in that: Two or more expansion deformation parts (12) are provided between adjacent collars (11), and each expansion deformation part (12) is evenly and symmetrically distributed on the upper and lower sides of the outer expansion tube (1).

3. The minimally invasive expandable spinal fusion device according to claim 2, characterized in that: The expansion deformation portions (12) between adjacent collars (11) are staggered with respect to each other in the circumferential direction.

4. The minimally invasive expandable spinal fusion device according to claim 1, characterized in that: The end of the movable end of the column inner core (2) is provided with a center hole (21), and the side wall of the center hole (21) is provided with a plurality of slots (211). The slots (211) divide the end of the column inner core (2) into a plurality of elastic arms (22), and the outer side wall of the free end of the elastic arm (22) is provided with a hook-shaped limiting protrusion (221); Before the outer expansion tube (1) is deformed, the inner core (2) of the column is shorter than the outer expansion tube (1) and is completely located inside the outer expansion tube (1); after the outer expansion tube (1) is deformed, the limiting protrusion (221) extends from the outer expansion tube (1) and deforms outwards, thereby blocking the movable end of the outer expansion tube (1).

5. The minimally invasive expandable spinal fusion device according to claim 4, characterized in that: A connecting hole (23) with internal threads is provided at the bottom of the central hole (21).

6. The minimally invasive expandable spinal fusion device according to claim 1, characterized in that: The length L of each expansion deformation portion (12) decreases in sequence along the axial direction, so that the protruding height H of each expansion deformation portion (12) decreases after deformation.

7. The minimally invasive expandable spinal fusion device according to claim 1, characterized in that: The outer wall of the inner core (2) of the column is in close contact with the inner wall of the outer expansion tube (1).

8. The minimally invasive expandable spinal fusion device according to claim 1, characterized in that: The end of the movable end of the outer expansion tube (1) is provided with a clamping notch (13).

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