Interbody fusion cage

Abstract

The invention relates to the technical field of medical instruments, in particular to an interbody fusion cage which comprises an interbody fusion cage body, the interbody fusion cage body is of a polyhedral structure and is implanted into the lumbar intervertebral space through an anterior lateral approach, and a screw channel and a connecting screw opening are formed in the front end position and the rear end position in the length direction of the interbody fusion cage body respectively; the screw channel is used for allowing screws to penetrate through the upper surface and the lower surface of the interbody fusion cage body, connected with the vertebral cancellous bone in a matched mode and fixed to the inner side of the lateral portion of the vertebral cancellous bone. The connecting screw is used for being connected with an installation instrument in a matched mode when the interbody fusion cage is implanted. By means of the screw channel, the fixing capacity of the interbody fusion cage can be effectively improved, better stability can be effectively provided for an OLIF operation through a proper implantation position and screw placement internal fixing operation, the occurrence risk of postoperative internal fixing related complications is effectively reduced, and the safety of the interbody fusion cage is improved. The effectiveness and the safety of the fusion cage in the lumbar vertebra front and outer side approach interbody fusion operation are improved.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically to an interbody fusion device. Background Technology

[0002] Spinal deformities are common spinal diseases that severely impact patients' quality of life. OLIF surgery is widely used in treating lumbar spine disorders and correcting spinal deformities. Specifically, OLIF surgery involves an oblique incision made in the patient's lateral abdomen, passing through the retroperitoneal space to reach the lateral aspect of the lumbar spine, avoiding the muscles, ligaments, and nerve tissues that would be damaged in traditional posterior approaches. By implanting an interbody fusion cage and bone graft, stability and fusion of the affected segment are achieved.

[0003] In existing technologies, interbody fusion cages rely solely on the contact surfaces between the cage and the endplates at both ends of the vertebral body for stability. These cages may also require posterior internal fixation surgery to assist in cage fixation. For example, patent application CN115192272B discloses an irregularly porous interbody fusion cage and its manufacturing method. This irregularly porous interbody fusion cage utilizes the high coefficient of friction of tantalum material to enhance the friction between the upper and lower surfaces of the cage and the spine, thereby improving the implantation stability. The remaining parts are made of titanium alloy, which maintains mechanical performance requirements despite a large porosity. Different sizes of cages can be printed based on the CT intervertebral disc data of different patients, achieving personalized customization.

[0004] Therefore, those skilled in the art need a new interbody fusion device to effectively solve the problem that existing interbody fusion devices rely solely on the friction of the endplate contact surface to maintain the stability of the device position, resulting in insufficient connection stability between the device and the vertebral body, low fusion rate, and high risk of complications. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this invention is to address the issues of insufficient connection stability between the fusion device and the vertebral body, low fusion rate, and high risk of complications associated with existing interbody fusion devices. To this end, this invention provides an interbody fusion device, comprising:

[0006] The main body of the intervertebral fusion device is a polyhedral structure. It is inserted obliquely into the intervertebral space of the lumbar spine through the anterolateral approach of the lumbar spine, avoiding major blood vessels and lumbar plexus nerves through the retroperitoneal space. The front and rear positions of the device along its length are respectively provided with screw channels and connecting screw holes.

[0007] The screw track is used for the screw to pass through the upper and lower surfaces of the intervertebral fusion cage body, connect with the vertebral cancellous bone, and be fixed to the lateral medial side of the vertebral cancellous bone; the above-mentioned lateral fixation method can avoid damage to the vertebral endplate, can preserve the integrity of the endplate to maintain the intervertebral space height, and at the same time reduce the risk of fusion cage subsidence.

[0008] The connecting screw is used to connect with the installation device when the interbody fusion device is implanted.

[0009] Optional, the interbody fusion device may also include:

[0010] Screws, including: titanium alloy internal fixation screws and / or bone cement screws; the bone cement screws are used for patients with osteoporosis.

[0011] Optionally, a bone graft cavity is provided in the central position of the interbody fusion device body, and the bone graft cavity is fixedly connected to the cancellous bone of the vertebral body through openings on the upper and lower surfaces.

[0012] Optionally, the bone graft cavity is located in the center of the interbody fusion device, and its side wall is ≥3mm away from the inner wall of the screw track to avoid the bone graft material interfering with screw fixation; the upper and lower opening edges of the bone graft cavity are ≥3mm away from the edge of the fusion device body to ensure the structural strength of the load-bearing surface.

[0013] Optionally, the screw track located on the upper surface has its two ends penetrating the front end and the upper surface of the interbody fusion device body, respectively;

[0014] The screw track located on the lower surface has its two ends penetrating the front end and the lower surface of the intervertebral fusion device body, respectively.

[0015] Optionally, the screw track is three, including: two screw tracks disposed on the upper surface of the intervertebral fusion device body, and one screw track disposed on the lower surface of the intervertebral fusion device body.

[0016] Optionally, the screw track is three, including: one screw track disposed on the upper surface of the intervertebral fusion device body, and two screw tracks disposed on the lower surface of the intervertebral fusion device body.

[0017] Optionally, at least two screw tracks on one side of the upper surface have different inclination angles. At least two screw tracks on one side of the lower surface also have different inclination angles. This differentiated angle design creates a cross-anchoring arrangement of the screws, improving resistance to rotation and displacement, and forming a three-dimensional locking effect.

[0018] Optionally, the upper and / or lower surfaces of the interbody fusion device body have a roughened fusion surface; the roughened fusion surface is closely connected to the vertebral body cross-section of the vertebral cancellous bone, so as to increase the contact area between the interbody fusion device body and the vertebral cancellous bone and promote bone graft fusion.

[0019] Optionally, the interbody fusion device is used for lumbar interbody fusion surgery via the anterolateral approach.

[0020] The technical solution of this invention has the following advantages:

[0021] 1. The interbody fusion device provided by the present invention comprises:

[0022] The main body of the intervertebral fusion device is a polyhedral structure. It is inserted obliquely into the intervertebral space of the lumbar spine through the anterolateral approach of the lumbar spine, avoiding major blood vessels and lumbar plexus nerves through the retroperitoneal space. The front and rear positions of the device along its length are respectively provided with screw channels and connecting screw holes.

[0023] The screw track is used for the screw to pass through the upper and lower surfaces of the interbody fusion device body, to connect with the vertebral cancellous bone, and to fix it to the lateral medial side of the vertebral cancellous bone;

[0024] The connecting screw is used to connect with the installation device when the interbody fusion device is implanted.

[0025] In this invention, screw channels are provided on the main body of the interbody fusion cage, through which screws pass to fix the upper and lower surfaces of the main body of the interbody fusion cage to the cancellous bone of the vertebral body. This structure effectively achieves lateral medial fixation of the cancellous bone of the vertebral body. This lateral fixation method avoids damage to the vertebral endplate, preserving the integrity of the endplate to maintain the intervertebral disc height, while reducing the risk of fusion cage subsidence.

[0026] The OLIF fusion device provided in this invention is implanted into the lumbar intervertebral space via an anterolateral approach. Through appropriate implantation location and screw fixation, it provides better stability for OLIF surgery, thereby reducing the risk of device displacement, failure, and fusion failure. Simultaneously, it reduces the necessity of additional posterior internal fixation surgery, thus decreasing the risk of postoperative internal fixation-related complications and improving the effectiveness and safety of the fusion device in anterolateral lumbar intervertebral fusion surgery.

[0027] 2. The interbody fusion device provided by the present invention further includes: screws, wherein the screws include: titanium alloy internal fixation screws and / or cemented screws; the cemented screws are used for patients with osteoporosis. In the present invention, the aforementioned matching screws can be cemented screws, which can provide reinforcement for patients with osteoporosis.

[0028] 3. The intervertebral fusion device provided by the present invention has screw channels on both the upper and lower surfaces of the main body of the intervertebral fusion device, thereby fixing it to the inner side of the cancellous bone of the vertebral body through the upper and lower surfaces of the main body of the intervertebral fusion device, further improving the connection stability between the fusion device and the vertebral body.

[0029] 4. The interbody fusion device provided by the present invention further includes roughened fusion surfaces on the upper and lower surfaces of the main body of the interbody fusion device. These roughened fusion surfaces effectively increase the contact area between the upper surface of the main body of the interbody fusion device and the vertebral body cross-section of the vertebral cancellous bone, as well as the contact area between the lower surface of the main body of the interbody fusion device and the vertebral body cross-section of the vertebral cancellous bone, thereby improving the roughened fusion surface between the upper surface of the main body of the interbody fusion device and the vertebral body cross-section, and thus promoting bone graft fusion.

[0030] 5. The intervertebral fusion device provided by this invention is used in lumbar intervertebral fusion surgery via the anterolateral approach. The preferred implantation location is slightly anterior to the center of the intervertebral space in the sagittal plane and midway between the intervertebral spaces in the coronal plane. This implantation location effectively restores the intervertebral space height and lumbar lordosis, while simultaneously achieving indirect decompression of the posterior spinal canal. Through the pre-defined screw channels and matching specialized screws, the device can achieve internal fixation. This type of OLIF fusion device is implanted into the lumbar intervertebral space via the anterolateral approach. Through appropriate implantation location and internal fixation techniques, it provides better stability for OLIF surgery, effectively reducing the risk of postoperative internal fixation-related complications and improving the effectiveness and safety of the fusion device in lumbar intervertebral fusion surgery via the anterolateral approach. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 A front view of the three-screw fixation fusion device provided for this invention, showing the positions of the three-screw channels and the connecting screw holes;

[0033] Figure 2 This is a top view of the three-screw internal fixation fusion device provided by the present invention;

[0034] Figure 3 This is a side view of the three-screw internal fixation fusion device provided by the present invention;

[0035] Figure 4 A schematic diagram of the screw structure provided by the present invention;

[0036] Figure 5This is a schematic diagram of the structure of the intervertebral fusion device body provided by the present invention, which is implanted into the intervertebral space of the lumbar spine.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1 – Interbody fusion cage body; 2 – Front end position; 3 – Rear end position; 4 – Screw track; 5 – Connecting screw hole; 6 – Screw; 7 – Upper surface; 8 – Lower surface; 9 – Bone graft cavity. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Example 1

[0042] See Figure 1 and Figure 2 , Figure 1 A front view of the three-screw internal fixation fusion device according to an embodiment of the present invention is shown, which shows the positions of the three screws and the connecting screw holes. Figure 2 A top view of the three-screw internal fixation fusion device in an embodiment of the present invention is shown.

[0043] The interbody fusion cage in this embodiment is used for lumbar interbody fusion surgery via the anterolateral approach. The interbody fusion cage includes:

[0044] The intervertebral fusion device body 1 is a polyhedral structure, implanted into the lumbar intervertebral space via an anterolateral approach, avoiding major blood vessels and lumbar plexus nerves through the retroperitoneal space, and obliquely implanted into the lumbar intervertebral space. Screw channels 4 and connecting screw holes 5 are respectively provided at its anterior end 2 and posterior end 3 along its length; as shown... Figure 5The diagram shows the structure of the interbody fusion cage implanted into the intervertebral space of the lumbar spine. The screw track 4 allows the screw 6 to pass through the upper surface 7 and lower surface 8 of the interbody fusion cage body 1, connecting with the vertebral cancellous bone and fixing it laterally and medially. This lateral fixation method avoids damage to the vertebral endplate, preserving its integrity to maintain the intervertebral space height and reducing the risk of cage subsidence. The connecting screw 5 is used to connect with the installation device during interbody fusion cage implantation. Through the screw track 4, the screw 6 can pass through it, fixing the upper and lower surfaces of the interbody fusion cage body 1 to the vertebral cancellous bone. This structure effectively achieves lateral and medial fixation of the vertebral cancellous bone, giving the interbody fusion cage the ability to perform internal fixation with screws.

[0045] Screw 6, such as Figure 4 As shown, the screw 6 includes a titanium alloy internal fixation screw and a bone cement screw; the bone cement screw is used for patients with osteoporosis. Of course, this embodiment does not specifically limit the material and structure of the screw 6; in other embodiments, the screw 6 can be made of other materials as needed.

[0046] In this embodiment, as Figure 2 The top view of the three-screw internal fixation fusion device shown, and Figure 3 The diagram shows a side view of the three-screw internal fixation fusion device. A bone graft cavity 9 is also provided in the central position of the main body 1 of the aforementioned interbody fusion device. The bone graft cavity 9 is fixedly connected to the cancellous bone of the vertebral body through openings on the upper surface 7 and the lower surface 8.

[0047] Furthermore, in a preferred embodiment, the bone graft cavity 9 is located in the center of the interbody fusion device body 1, and its side wall is ≥3mm away from the inner wall of the screw track 4 to avoid the bone graft material interfering with the screw fixation; the upper and lower opening edges of the bone graft cavity 9 are ≥3mm away from the edge of the fusion device body to ensure the structural strength of the load-bearing surface.

[0048] Furthermore, such as Figure 1 As shown, the screw track 4 located on the upper surface 7 has its two ends penetrating the front end position 2 and the upper surface 7 of the interbody fusion cage body 1, respectively; the screw track 4 located on the lower surface 8 also has its two ends penetrating the front end position 2 and the lower surface 8 of the interbody fusion cage body 1, respectively. By providing screw tracks 4 on both the upper surface 7 and the lower surface 8 of the interbody fusion cage body 1, the upper and lower surfaces of the interbody fusion cage body 1 are respectively fixed to the medial side of the vertebral cancellous bone, further improving the connection stability between the fusion cage and the vertebral body.

[0049] In a preferred embodiment, such as Figure 1As shown: There are three screw tracks 4, including two screw tracks 4 located on the upper surface 7 of the intervertebral fusion cage body 1, and one screw track 4 located on the lower surface 8 of the intervertebral fusion cage body 1. Furthermore, at least two screw tracks 4 located on one side of the upper surface 7 have different inclination angles. This differentiated angle design allows the screws to be arranged in a cross-anchoring layout, improving anti-rotation and anti-displacement capabilities and forming a three-dimensional locking effect.

[0050] In another preferred embodiment, there are three screw tracks 4, including one screw track 4 disposed on the upper surface 7 of the interbody fusion cage body 1, and two screw tracks 4 disposed on the lower surface 8 of the interbody fusion cage body 1. Furthermore, at least two screw tracks 4 located on one side of the lower surface 8 have different inclination angles. This differentiated angle design allows the screws to be arranged in a cross-anchoring layout, improving anti-rotation and anti-displacement capabilities and forming a three-dimensional locking effect.

[0051] In another preferred embodiment, there are multiple screw tracks 4, including two screw tracks 4 disposed on the upper surface 7 of the interbody fusion cage body 1, and two screw tracks 4 disposed on the lower surface 8 of the interbody fusion cage body 1. Furthermore, at least two screw tracks 4 located on one side of the upper surface 7 have different inclination angles. At least two screw tracks 4 located on one side of the lower surface 8 have different inclination angles. This differentiated angle design allows the screws to be arranged in a cross-anchoring layout, improving anti-rotation and anti-displacement capabilities and forming a three-dimensional locking effect.

[0052] In a preferred embodiment, the upper surface 7 and lower surface 8 of the interbody fusion device body 1 have roughened fusion surfaces. These roughened fusion surfaces are closely connected to the vertebral body cross-section of the vertebral cancellous bone, thereby increasing the contact area between the interbody fusion device body 1 and the vertebral cancellous bone and promoting bone graft fusion. The aforementioned roughened fusion surfaces effectively increase the contact area between the upper surface 7 of the interbody fusion device body 1 and the vertebral body cross-section of the vertebral cancellous bone, as well as the contact area between the lower surface 8 of the interbody fusion device body 1 and the vertebral body cross-section, thereby increasing the roughened fusion surface between the upper surface of the interbody fusion device body 1 and the vertebral body cross-section, and thus promoting bone graft fusion. Of course, in this embodiment, the specific location of the roughened fusion surfaces is not specifically limited. In other embodiments, the roughened fusion surfaces may be provided only on one of the upper surface 7 and lower surface 8 of the interbody fusion device body 1 as needed. Alternatively, the aforementioned roughened fusion surfaces may not be provided on the interbody fusion device body 1.

[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An interbody fusion device, characterized in that, include: The intervertebral fusion device body (1) is a polyhedral structure. It is inserted obliquely into the intervertebral space through the anterolateral approach of the lumbar spine, avoiding major blood vessels and lumbar plexus nerves via the retroperitoneal space. The front end (2) and rear end (3) of the intervertebral fusion device are respectively provided with screw channels (4) and connecting screw holes (5). The screw track (4) is used for the screw (6) to pass through the upper surface (7) and lower surface (8) of the intervertebral fusion device body (1), to cooperate with the vertebral cancellous bone, and to be fixed to the lateral medial side of the vertebral cancellous bone; The connecting screw (5) is used to connect with the installation device when the interbody fusion device is implanted.

2. The interbody fusion device according to claim 1, characterized in that, Also includes: Screws (6), said screws (6) include: titanium alloy internal fixation screws and / or bone cement screws; The bone cement screw is used for patients with osteoporosis.

3. The interbody fusion device according to claim 1, characterized in that, The intervertebral fusion device body (1) is also provided with a bone graft cavity (9) in the center of the interior. The bone graft cavity (9) is fixedly connected to the cancellous bone of the vertebral body through the openings of the upper surface (7) and the lower surface (8).

4. The interbody fusion device according to claim 3, characterized in that, The bone graft cavity (9) is located in the center of the intervertebral fusion device body (1), and its side wall is ≥3mm away from the inner wall of the screw track (4) to avoid the bone graft material interfering with the screw fixation; the upper and lower opening edges of the bone graft cavity (9) are ≥3mm away from the edge of the fusion device body to ensure the structural strength of the load-bearing surface.

5. The interbody fusion device according to claim 1, characterized in that, The screw track (4) located on the upper surface (7) has its two ends penetrating the front end (2) and the upper surface (7) of the intervertebral fusion device body (1), respectively; The screw track (4) located on the lower surface (8) has its two ends penetrating the front end (2) and the lower surface (8) of the intervertebral fusion device body (1), respectively.

6. The interbody fusion device according to claim 1, characterized in that, The screw track (4) consists of three tracks, including two screw tracks (4) located on the upper surface (7) of the intervertebral fusion cage body (1), and one screw track (4) located on the lower surface (8) of the intervertebral fusion cage body (1); or, The screw track (4) consists of three tracks, including one screw track (4) located on the upper surface (7) of the intervertebral fusion body (1) and two screw tracks (4) located on the lower surface (8) of the intervertebral fusion body (1).

7. The interbody fusion device according to claim 6, characterized in that, At least two of the screw tracks (4) located on one side of the upper surface (7) have different inclination angles; or at least two of the screw tracks (4) located on one side of the lower surface (8) have different inclination angles.

8. The interbody fusion device according to claim 1, characterized in that, The upper surface (7) and / or lower surface (8) of the intervertebral fusion device body (1) have a rough fusion surface; the rough fusion surface is closely connected to the vertebral body cross section of the vertebral cancellous bone, so as to increase the contact area between the intervertebral fusion device body (1) and the vertebral cancellous bone and promote bone graft fusion.

9. The interbody fusion device according to claim 8, characterized in that, The rough fusion surface has a microporous structure with a depth of 0.5–1 mm; this can promote osteoblast attachment and growth, increase the osteointegration area, and at the same time avoid stress shielding caused by excessive roughness.

10. The interbody fusion device according to any one of claims 1 to 9, characterized in that, The main body of the intervertebral fusion device (1) is used for intervertebral fusion surgery via the anterolateral approach of the lumbar spine.

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