Screw-in type self-opening nested side mass fusion cage and matching tool and use method thereof

Abstract

The invention relates to a screw-in type self-opening nesting lateral mass fusion cage and a matched tool and a using method thereof.The fusion cage comprises a fusion cage body, the rear end of the fusion cage body is of an open structure, a first containing cavity penetrating through the upper portion and the lower portion is formed in the rear end of the fusion cage body, and the fusion cage further comprises a bone groove which is provided with a second containing cavity penetrating through the upper portion and the lower portion; the bone groove is connected with the fusion cage body, and the bone groove is located in the first containing cavity. The matching tool further comprises a screwing-in rod which is provided with a threaded head used for being screwed into the fusion cage body. The using method comprises the following steps that the second containing cavity of the bone groove is filled with the autogenous iliac bone or the allogeneic bone in vitro; implanting the fusion cage body into an atlantoaxial lateral mass joint gap of a patient by using a screw-in tool; the bone groove is embedded into the first containing cavity of the fusion cage body. According to the screw-in type lateral mass fusion cage, the application problems that the proportion of a structural filling bone block of an existing screw-in type lateral mass fusion cage is relatively low, the bone block is prone to falling off in the implanting process, and the fusion effect needs to be further improved can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a screw-in self-expanding nested lateral mass fusion device and its supporting tools and usage methods. Background Art

[0002] The screw-in lateral mass fusion device is a medical device mainly used for treating spinal diseases such as atlantoaxial dislocation, basilar invagination, and upper cervical spine deformities. This fusion device generally includes a fusion device body and a screw-in screw. The fusion device body is provided with a screw-in hole that matches the screw-in screw, enabling the fusion device body to firmly enter the atlantoaxial lateral mass joint space through the screw-in screw. Some advanced screw-in lateral mass fusion device designs also consider increasing the bone surface contact area to optimize the bone graft fusion effect.

[0003] However, the current screw-in lateral mass fusion device faces some problems in use. Among them, the relatively low proportion of the overall structure of the fusion device filled with autologous iliac bone or allogeneic bone is a key issue. Due to the limited space of the bone graft groove, the amount of autologous iliac bone or allogeneic bone implanted is insufficient, which may affect the bone fusion effect and fusion speed. Specifically, if the autologous iliac bone or allogeneic bone filling is insufficient, it may lead to a reduction in the effective contact area between the fusion device and the surrounding bones, thereby affecting bone growth and connection. Moreover, due to the limitation of the filling amount of autologous iliac bone or allogeneic bone, and the easy dropping of bone blocks during the screw-in process of the fusion device, the overall fusion effect also needs to be further improved. Summary of the Invention

[0004] In order to overcome the defects of the prior art, the present invention proposes a screw-in self-expanding nested lateral mass fusion device and its supporting tools and usage methods, which can solve the application problems of the current screw-in lateral mass fusion device, such as the relatively low proportion of the structure filled with autologous iliac bone or allogeneic bone, the easy dropping of bone blocks, and the need for further improvement of the fusion effect.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A screw-in self-expanding nested lateral mass fusion device provided by the present invention includes a fusion device body. The rear end of the fusion device body has an open structure. The rear end of the fusion device body is provided with a first accommodation cavity that penetrates up and down. It also includes a bone groove. The bone groove is provided with a second accommodation cavity that penetrates up and down. The bone groove is connected to the fusion device body, and the bone groove is located in the first accommodation cavity.

[0007] Preferably, the fusion device body and the bone groove are in snap-fit.

[0008] Preferably, each of the left and right inner sides of the fusion device body is provided with a sliding groove, and the corresponding positions of the bone groove are provided with sliding strips that match the sliding grooves.

[0009] Preferably, the structure on the bone groove is a rectangular frame body that penetrates up and down, and the second accommodation cavity is located within the rectangular frame body.

[0010] Preferably, a connecting portion is provided at the rear side of the bone groove for placing the bone groove into the first accommodation cavity with the aid of a tool.

[0011] Preferably, serrated clamping portions are provided on the upper side and / or the lower side of the fusion device body.

[0012] Preferably, the material of the fusion device body is medical titanium alloy, and the material of the bone groove is medical PEEK material.

[0013] A matching tool for a screw-in type self-expanding nested lateral mass fusion device provided by the present invention further includes a screw-in rod, and a threaded head for screwing into the fusion device body is provided on the screw-in rod.

[0014] Preferably, a threaded structure is provided in the first half of the opening at the front end of the fusion device body, and a convex column structure matching the second half of the opening is provided at the front end of the screw-in rod.

[0015] A method for using a screw-in type self-expanding nested lateral mass fusion device provided by the present invention includes the following steps:

[0016] S0, filling autologous iliac bone or allogeneic bone into the second accommodation cavity of the bone groove in vitro;

[0017] S1, implanting the fusion device body into the atlantoaxial lateral mass joint space of a patient using a screw-in type tool; if the implanting position is too deep, the fusion device body can be retracted to a proper position using a connecting type tool;

[0018] S2, embedding the bone groove into the first accommodation cavity of the fusion device body using a connecting type tool.

[0019] Advantages of the present invention:

[0020] The present invention provides a screw-in type self-expanding nested lateral mass fusion device, its matching tool and usage method. The fusion device body adopts an open structure design at the rear end. This design not only facilitates the implanting operation during the surgical procedure, but more importantly, it forms a first accommodation cavity that penetrates up and down. The presence of the first accommodation cavity enables the introduction of the bone groove part of the externally implanted bone. By splitting the traditional lateral mass fusion device into two components and implanting them successively, it is possible to significantly increase the filling ratio of autologous iliac bone or allogeneic bone while ensuring implanting safety in terms of structure, thereby effectively accelerating the bone fusion speed and improving the bone fusion rate. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 The three-dimensional view of the screw-in self-expanding nested lateral mass fusion device according to the first embodiment of the present invention Figure 1 ;

[0023] Figure 2 The three-dimensional view of the screw-in self-expanding nested lateral mass fusion device according to the first embodiment of the present invention Figure 2 ;

[0024] Figure 3 The exploded view of the screw-in self-expanding nested lateral mass fusion device according to the first embodiment of the present invention;

[0025] Figure 4 The three-dimensional view of the fusion device body according to the first embodiment of the present invention Figure 1 ;

[0026] Figure 5 The three-dimensional view of the fusion device body according to the first embodiment of the present invention Figure 2 ;

[0027] Figure 6 The three-dimensional view of the bone groove according to the first embodiment of the present invention;

[0028] Figure 7 The three-dimensional view of the screw-in rod according to the first embodiment of the present invention;

[0029] Figure 8 The usage schematic diagram of the screw-in self-expanding nested lateral mass fusion device according to the first embodiment of the present invention Figure 1 ;

[0030] Figure 9 The three-dimensional view of the adjusting screw rod according to the first embodiment of the present invention;

[0031] Figure 10 The three-dimensional view of the placement screw rod according to the first embodiment of the present invention;

[0032] Figure 11 The usage schematic diagram of the screw-in self-expanding nested lateral mass fusion device according to the first embodiment of the present invention Figure 2 .

[0033] In the figure:

[0034] 1 - Fusion device body; 11 - Card slot part; 13 - Slide groove; 14 - Card slot; 2 - Bone groove; 21 - Connection part; 23 - Slide bar; 24 - Snap part; 31 - First accommodation cavity; 32 - Second accommodation cavity; 4 - Screw-in rod; 41 - Threaded head; 42 - Convex column structure; 5 - Mounting threaded rod. Detailed implementation mode

[0035] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation modes.

[0036] Embodiment 1:

[0037] As Figure 1-11 shown, a screw-in self-expanding nested lateral mass fusion device provided in this embodiment includes a fusion device body 1. The rear end of the fusion device body 1 is of an open structure. A first accommodation cavity 31 penetrating up and down is provided at the rear end of the fusion device body 1. It also includes a bone groove 2. A second accommodation cavity 32 penetrating up and down is provided in the bone groove 2. The bone groove 2 is connected to the fusion device body 1, and the bone groove 2 is located in the first accommodation cavity 31. In the solution, the fusion device body adopts an open structure design at the rear end. This design not only facilitates the implantation operation during the surgery, but more importantly, it forms a first accommodation cavity penetrating up and down. The existence of this cavity provides an accommodation space for carrying materials such as autologous iliac bone or allogeneic bone, thereby directly increasing the filling ratio of autologous iliac bone or allogeneic bone in the fusion device. The filling ratio can reach more than 80%, providing a more sufficient material basis for bone regeneration. More ingeniously, the solution also introduces a key component, the bone groove. A second accommodation cavity penetrating up and down is also provided inside the bone groove. When in use, after the fusion device body is screwed into the atlantoaxial lateral mass joint space of the patient, the bone groove is stably nested and implanted. Before implantation, the inside of the bone groove is filled with autologous iliac bone or allogeneic bone, so that the bone groove can better "wrap" the bone block, and it can reduce the loss of the bone block due to unstable reasons such as sliding during the screwing process in the traditional method. This design not only further expands the filling area of autologous iliac bone or allogeneic bone, but also through the ingenious connection between the bone groove and the fusion device body, enables the bone groove to be accurately positioned in the first accommodation cavity, forming a multi-level and multi-dimensional bone fusion environment. Such a structural design not only optimizes the distribution of autologous iliac bone or allogeneic bone inside the fusion device, but also promotes the close contact and effective fusion of autologous iliac bone or allogeneic bone with the surrounding bone tissue, greatly improving the bone fusion efficiency and bone fusion quality. Therefore, through the open rear-end design of the fusion device body, the expansion of the first accommodation cavity, and the introduction of the bone groove and the second accommodation cavity, the solution significantly improves the filling ratio of autologous iliac bone or allogeneic bone in terms of structure, and effectively accelerates the bone fusion speed and increases the bone fusion rate.

[0038] Preferably, the fusion device body 1 and the bone groove 2 are snap-fitted. Specifically, a slide groove 13 is provided on the left and right inner sides of the fusion device body 1, and a slide bar 23 matching the slide groove 13 is provided at the corresponding part of the bone groove 2. The fusion device body 1 and the bone groove 2 are snap-fitted and fixed through the above structure. Further, a buckle portion 24 is provided on one side of the slide bar 23, and a slot 14 matching the buckle portion 24 is provided on the corresponding side of the slide groove 13. The snap-fitting not only ensures a stable connection between the bone groove and the fusion device body, avoids the problems of bone groove displacement caused by looseness and the falling of autologous ilium or allogeneic bone leading to poor bone fusion effect, but also greatly simplifies the operation steps during the operation and improves the operation efficiency. In addition, the design flexibility of the snap-fit ​​structure allows the surgeon to make fine adjustments when necessary to ensure the optimal alignment between the bone groove and the fusion device body, thereby effectively preventing the loss of the bone groove position, optimizing the distribution of autologous ilium or allogeneic bone, and promoting the smooth progress of the bone fusion process.

[0039] Preferably, the structure on the bone groove 2 is a rectangular frame that runs through from top to bottom, and the second accommodating cavity 32 is located in the rectangular frame. The openness and regularity of the rectangular frame make it easier and more evenly possible to fill the autologous iliac bone or allogeneic bone into the second accommodating cavity, avoiding the problem of filling dead corners or uneven accumulation of autologous iliac bone or allogeneic bone that may occur in traditional designs. In addition, the rectangular frame has a high structural strength and can resist pressure changes after implantation to maintain the long-term stability of the bone groove. This design not only improves the efficiency and quality of bone fusion, but also provides more favorable conditions for postoperative bone fusion, and is a key link in improving the performance of the fusion device.

[0040] Preferably, a connecting portion 21 is provided on the rear side of the bone groove 2 for a tool to place the bone groove 2 into the first accommodating cavity 31. The design of providing the connecting portion on the rear side of the bone groove greatly facilitates the surgical operation, especially the positioning and installation process of the bone groove. The connecting portion not only provides a clear fulcrum for surgical tools, so that the bone groove can be accurately and quickly placed in the first accommodating cavity of the fusion device body, but also ensures the stability and accuracy of the bone groove during the implantation process. This design reduces the complexity and time cost of the surgical operation, reduces the surgical risk, and improves the success rate of the fusion device implantation. In addition, the presence of the connecting portion also facilitates postoperative inspection and adjustment, and is an important innovation to improve surgical efficiency and safety.

[0041] Preferably, a serrated retaining portion 11 is provided on the upper side and / or the lower side of the fusion device body 1. This design is intended to improve the stability and anti-rotation ability of the fusion device after implantation. The serrated retaining portion can form a tight fit with the surrounding bone tissue, effectively preventing the fusion device from being displaced or rotated due to external forces after surgery.

[0042] Preferably, the material of the fusion device body 1 is medical titanium alloy, and the material of the bone groove 2 is medical PEEK material. As a high-performance metal material, titanium alloy has excellent biocompatibility and corrosion resistance. In the human body environment, titanium alloy can maintain good stability and is not likely to cause inflammatory reactions or rejection reactions. This is of great significance for promoting the bone fusion process and reducing postoperative complications. In addition, titanium alloy also has the characteristics of high strength and low density. High strength ensures that the fusion device can withstand sufficient mechanical loads after implantation and is not prone to deformation or fracture; while low density reduces the weight of the fusion device and the burden on the patient. Titanium alloy also has good processing performance and plasticity. This enables the fusion device to be customized designed and manufactured according to the specific anatomical structure and surgical needs of the patient. This customized service not only improves the accuracy and effect of the surgery, but also meets the personalized needs of different patients. The advantages of using medical PEEK as the selected material for the bone groove are as follows: 1. Good biocompatibility; 2. Since the PEEK material is not visible on CT, the fusion degree of the lateral mass joint can be more easily evaluated after the operation.

[0043] The usage process of the screw-in self-expanding nested lateral mass fusion device is as follows:

[0044] Step 1, determine the lateral mass anatomical structure through CT / MRI, plan the implantation path of the screw-in self-expanding nested lateral mass fusion device, and initially select the model of the screw-in self-expanding nested lateral mass fusion device according to the patient's lateral mass size;

[0045] Step 2, make a posterior midline incision, strip the paravertebral muscles to the outer edge of the lateral mass joint, and expose the target segment;

[0046] Step 3, fill autologous iliac bone (iliac bone harvesting is required) or allogeneic bone into the second accommodation cavity 32 of the bone groove 2 in vitro;

[0047] Step 4, pre-drill the screw channels in the conventional pedicle screw placement method for the atlas and axis. After exploring the integrity of the screw channels, implant appropriate-sized pedicle screws. After completely releasing the lateral mass joint using the lateral mass joint release tool, use an appropriate-sized tap to gradually expand the screw channel at the midpoint of the lateral mass joint at an angle perpendicular to the coronal plane (to avoid damaging the vertebral artery or nerve root). After tapping, screw the fusion device body 1 along the threaded head 41 through the screwing rod 4. During the screwing process, the step-by-step lateral mass joint expansion step is completed, providing conditions for atlantoaxial reduction. After completely screwing in the fusion device, confirm the position, depth, and angle of the fusion device through intraoperative X-ray / CT, and gently lift the fusion device to check if it is firm and without looseness. This process needs to ensure that the fusion device body is completely embedded in the bone mass to avoid "hanging in the air" and causing looseness;

[0048] Step 5, embed the bone groove 2 filled with autologous iliac bone or allogeneic bone along the sliding groove 13 into the first accommodation cavity 31 of the fusion device body 1;

[0049] Step 6: Insert a titanium rod of appropriate length to connect the pedicle screws of the atlas and axis vertebrae, tighten the nuts, and perform fluoroscopy again to confirm the position, depth, and angle of the screws and the fusion device.

[0050] Step 7: Close the incision and suture the fascia, subcutaneous tissue, and skin layer by layer.

[0051] Among them, the opening at the front end of the fusion device body 1 is provided with a threaded structure only in the first half, and no threaded structure is provided in the second half, so as to ensure that when the fusion device body 1 is screwed in, the convex column structure 42 at the frontmost end of the screwing rod is inserted for positioning and limitation, and the fusion device body 1 can be successfully implanted into the fusion site of the patient. At this time, an adjusting threaded rod is also equipped. The front end of the adjusting threaded rod is provided with a threaded structure matching the front end of the fusion device body 1. When it is found that the screwing position of the fusion device body is inappropriate during Step 4, the operator can thread-fix the adjusting threaded rod and the fusion device body 1, and then pull the adjusting threaded rod backward to re-adjust the position of the fusion device body 1.

[0052] During the process of placing the bone groove 2 in Step 5, the connecting portion 21 provided at the rear side of the bone groove 2 is a threaded structure, and a corresponding placing threaded rod is also equipped. The front end of the placing threaded rod is provided with a threaded structure matching the connecting portion 21. During use, after the placing threaded rod and the connecting portion 21 are thread-fixedly connected, the bone groove 2 is placed into the first accommodating cavity 31 along the provided clamping structure. For the convenience of application, the threaded structures of the placing threaded rod and the adjusting threaded rod can be set to the same threaded structure without the need to additionally increase supporting instruments.

[0053] For the patients treated by the above method, their bone fusion conditions are significantly improved compared with the traditional screwed-in lateral mass fusion device. Clinical retrospective studies have shown that compared with the traditional screwed-in lateral mass fusion device, the bone fusion rate 3 months after the implantation of the screwed-in self-expanding nested lateral mass fusion device has increased by 18.6%, and the fusion time has been significantly reduced (p < 0.05), and all patients have achieved bony fusion.

[0054] The present invention is described by way of preferred embodiments. Those skilled in the art will know that without departing from the spirit and scope of the present invention, various changes or equivalent substitutions can be made to these features and embodiments. The present invention is not limited by the specific embodiments disclosed herein, and other embodiments falling within the scope of the claims of this application belong to the scope of protection of the present invention.

Claims

1. A screw-in self-expanding nested lateral mass fusion device, characterized in that: It comprises a fusion device body (1), the rear end of the fusion device body (1) is an open structure, and the rear end of the fusion device body (1) is provided with a first accommodating cavity (31) that passes through the upper and lower parts; It also includes a bone groove (2), the bone groove (2) is provided with a second accommodating cavity (32) that passes through from top to bottom, the bone groove (2) is connected to the fusion device body (1), and the bone groove (2) is located in the first accommodating cavity (31).

2. The screw-in self-expanding nested lateral mass fusion device according to claim 1, characterized in that: The fusion device body (1) and the bone groove (2) are snap-fitted.

3. The screw-in self-expanding nested lateral mass fusion device according to claim 2, characterized in that: The left and right inner sides of the fusion device body (1) are each provided with a slide groove (13), and the corresponding position of the bone groove (2) is provided with a slide bar (23) matching the slide groove (13).

4. The screw-in self-expanding nested lateral mass fusion device according to claim 1, characterized in that: The structure on the bone groove (2) is a rectangular frame that penetrates from top to bottom, and the second accommodating cavity (32) is located in the rectangular frame.

5. The screw-in self-expanding nested lateral mass fusion device according to claim 1, characterized in that: A connecting portion (21) is provided on the rear side of the bone groove (2) for allowing a tool to place the bone groove (2) into the first accommodating cavity (31).

6. The screw-in self-expanding nested lateral mass fusion device according to claim 1, characterized in that: The upper side and / or the lower side of the fusion device body (1) is provided with a sawtooth-shaped locking portion (11).

7. The screw-in self-expanding nested lateral mass fusion device according to claim 1, characterized in that: The material of the fusion device body (1) is a medical titanium alloy, and the material of the bone groove (2) is a medical PEEK material.

8. A matching tool for a screw-in self-expanding nested lateral mass fusion device according to any one of claims 1 to 7, characterized in that: It also comprises a screw-in rod (4), on which a threaded head (41) for being screwed into the fusion device body (1) is provided.

9. The supporting tool of the screw-in self-expanding nested lateral mass fusion device according to claim 8, characterized in that: The opening at the front end of the fusion device body (1) is provided with a thread structure in the front half; The front end of the screw-in rod (4) is provided with a convex column structure (42) matching the rear half of the opening.

10. A method for using the screw-in self-expanding nested lateral mass fusion device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S0, filling the second accommodating cavity (32) of the bone groove (2) with autologous iliac bone or allogeneic bone in vitro; S1, using a screw-in tool to implant the fusion device body (1) into the atlantoaxial lateral mass joint space of the patient; if the implantation position is too deep, a connecting tool can be used to withdraw the fusion device body (1) to a suitable position; S2, using a connecting tool to embed the bone groove (2) into the first accommodating cavity (31) of the fusion device body (1).

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