Modular cervical interbody fusion cage

Abstract

The present invention discloses a modular cervical intervertebral fusion device, which belongs to the field of spinal fusion instruments. It includes an I-shaped support member and a side wall connector for providing a support function. The I-shaped support member includes a first support rod, a second support rod, and a longitudinal connecting rod. The first support rod is provided with a first connecting member at both ends, and the second support rod is provided with a second connecting member at both ends. The two ends of the longitudinal connecting rod are connected to the first support rod and the second support rod as a whole, and the I-shaped support member formed by the first support rod, the longitudinal connecting rod and the second support rod is in an I-shape. The actual application results show that based on the new structural design, bone grafting of the uncovertebral joint can be achieved, which can effectively improve the fusion rate. The fusion rate of the uncovertebral joint on the bone grafting side is higher than that on the uncovertebral joint without bone grafting, which has significant progressive significance. At the same time, based on the improvement of the structure, corresponding selection can be made for different patients to ensure the best clinical effect and maximum fusion.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, in particular to the field of spinal fusion devices, and specifically to a modular cervical intervertebral fusion device. Background Art

[0002] Spinal fusion technology has been used to treat various spinal diseases for decades. The initial fusion technology included a large amount of muscle release, autologous bone transplantation, and long-term traction bed fixation. Since the development of spinal internal fixation technology, the success rate of spinal fusion has been improved, the patient's recovery time has been shortened, and more options for surgical treatment have been left. In order to reduce the failure rate of simple posterior spinal fusion and internal fixation surgery, the concept of anterior column support fusion has gradually emerged. Initially, bone was transplanted into the intervertebral space through the anterior and posterior approaches to better improve the blood supply to the affected part, bear the load, and maintain the physiological curve of the spine. However, transplanted bone as a single support cannot make the spine sufficiently strong. Simple anterior and posterior fusion of the spine may cause bone fracture and pseudoarthrosis formation, while intervertebral fusion devices such as titanium mesh and rectangular carbon fiber fusion devices can avoid the occurrence of the above complications.

[0003] Badgy and Kuslich pioneered the technology of single intervertebral fusion cage. In 1986, Badgy and Kuslich designed an intervertebral fusion cage suitable for the human body, namely the BAK (Bagby and Kuslich) system, and used it to treat degenerative low back pain. A considerable part of these technologies are based on Badgy's practical experience of initially using a single cylindrical metal mesh to fix it on the cervical spine of a horse. In theory, the intervertebral fusion cage can maintain the stability of each fusion segment through the contraction of the muscles around the vertebral body and the tension of the ligaments around the vertebral body. Since the birth of the intervertebral fusion cage, people have conducted a lot of research and development.

[0004] Chinese patent application CN201922306545.6 discloses an intervertebral fusion device with adjustable height and its supporting tools. The intervertebral fusion device comprises a fusion device body, a bone grafting cavity is provided in the fusion device body, the fusion device body comprises an upper end plate, a lower end plate, a secondary support block, a main support block and an adjusting screw, the upper end plate and / or the lower end plate are provided with a through bone grafting window, the bone grafting window is connected to the bone grafting cavity, the main support block is connected to the upper end plate and the lower end plate through an inclined slider mechanism, one side of the secondary support block abuts against the upper end plate and / or the lower end plate, the middle part of the secondary support block is provided with a through connecting hole, the main support block is provided with a transversely through screw hole, the adjusting screw passes through the connecting hole and is threadedly connected to the screw hole, the end of the adjusting screw away from the screw hole is provided with a transmission groove, the middle part of the adjusting screw is provided with a through bone grafting hole, and the bone grafting hole is connected to the bone grafting cavity through the screw hole.

[0005] Chinese patent application CN201922305638.7 discloses a sliding expandable intervertebral fusion device and its supporting tools, the intervertebral fusion device comprises a fusion device body and an expansion block, the fusion device body comprises a connecting portion and an expansion portion, the connecting portion is provided with a through adjustment hole, the expansion portion comprises an upper clamping body and a lower clamping body both connected to the connecting portion, an adjustment channel is provided between the upper clamping body and the lower clamping body, a through bone grafting window is provided on the upper clamping body and / or the lower clamping body, the adjustment hole is connected to the adjustment channel, a plurality of self-locking grooves are provided on the adjustment channel, the expansion block slides in the adjustment channel and is locked in the self-locking groove by the upper clamping body and the lower clamping body, a screw hole is provided in the expansion block, and the screw hole is connected to the adjustment hole through the adjustment channel.

[0006] Chinese patent application CN201911211904.8 discloses an intervertebral fusion device, which includes a fusion device body, wherein the fusion device body includes a fixing plate and a support block, wherein the fixing plate is connected to one end of the support block and is integrally formed with the support block, wherein the fixing plate is provided with a plurality of fixing through holes for connecting fixing screws for fixing, wherein a connecting groove is provided in the fixing through hole and a C-shaped ring is rotatably connected through the connecting groove; wherein a supporting through hole is provided on the support block and passes through the support block laterally, and a mesh structure is provided on the side surface of the support block and the inner wall of the supporting through hole.

[0007] Chinese patent application CN201911122239.5 discloses an intervertebral fusion device, which includes a shaft body, a first distraction piece and a fusion body. The first distraction piece is installed on the shaft body and can move axially along the shaft body. The first distraction piece has an inner end and an outer end distributed along the radial direction of the shaft body, and the inner end is connected to the shaft body. The fusion body is circumferentially arranged around the shaft body and connected to the outer end of the first distraction piece. A first slideway is opened on the inner wall of the fusion body, and an angle is set between the extension direction of the first slideway and the outer wall of the fusion body. The outer end of the first distraction piece is movably arranged in the first slideway.

[0008] Chinese patent application CN201910937467.1 discloses an expandable intervertebral fusion device, which includes an integrated fusion device body, which includes: a first pressing portion, on which a first through hole is formed, a first guide groove is formed on the side, a first positioning tooth is provided on the plate surface, and a first guide sliding surface is provided on the inner plate surface; a second pressing portion, which is a symmetrical structure with the first pressing portion; a mounting portion, which is fixedly connected to one end of the first pressing portion and the second pressing portion, and the other end of the first pressing portion and the second pressing portion is a free end; a mounting through hole is provided on the mounting portion; an expansion block, which is slidably arranged between the first pressing portion and the second pressing portion, and abuts against the first guide sliding surface and the second guide sliding surface.

[0009] Chinese patent application CN201510541160.1 discloses a cervical uncinate vertebrae joint fusion device, which includes an uncinate vertebrae joint fusion component and an intervertebral elastic support body. The cross-section of the intervertebral elastic support body is trapezoidal, and the front end is a small end. There are two uncinate vertebrae joint fusion components, which are respectively connected to the two lumbar outer surfaces of the intervertebral elastic support body. The uncinate vertebrae joint fusion component is a cylindrical mesh structure, and a baffle is connected to the side of the uncinate vertebrae joint bone graft fusion component away from the intervertebral elastic support body.

[0010] In summary, various intervertebral fusion devices with different structures have been disclosed in the prior art, but how to further improve the intervertebral fusion device to improve the treatment effect of patients and reduce the cost of the device is still an urgent problem to be solved. To this end, the inventor of this application has developed a modular cervical intervertebral fusion device based on many years of medical practice and research and exploration of intervertebral fusion devices. Summary of the invention

[0011] The purpose of the present invention is to provide a modular cervical intervertebral fusion device to address the above-mentioned problems. The actual application results show that based on the new structural design, bone grafting of the uncovertebral joint can be achieved, which can effectively improve the fusion rate. The uncovertebral joint fusion rate on the bone grafting side is higher than that on the uncovertebral joint without bone grafting, which has significant progressive significance. At the same time, based on the improvement of the structure, corresponding selection can be made for different patients to ensure the best clinical effect and maximum fusion.

[0012] In order to achieve the above object, the present invention adopts the following technical solution:

[0013] A modular cervical intervertebral fusion device, comprising an I-shaped support member and a side wall connector for providing a support function, wherein the I-shaped support member comprises a first support rod, a second support rod, and a longitudinal connecting rod, wherein both ends of the first support rod are respectively provided with a first connector, and both ends of the second support rod are respectively provided with a second connector;

[0014] The two ends of the longitudinal connecting rod are respectively connected to the first supporting rod and the second supporting rod as a whole, and the I-shaped supporting member formed by the first supporting rod, the longitudinal connecting rod and the second supporting rod is in an I-shaped shape;

[0015] The side wall connector is a group, and the cross section of the side wall connector along the horizontal direction is C-shaped; one end of the side wall connector is provided with a third connector that matches the first connector, and the other end of the side wall connector is provided with a fourth connector that matches the second connector, and the side wall connector is detachably connected to the I-shaped support member through the third connector and the fourth connector at both ends thereof;

[0016] A bone grafting cavity is formed between the I-shaped support piece and the side wall connecting piece.

[0017] The third connecting member and the fourth connecting member can limit the side wall connecting member and the I-shaped supporting member in the horizontal direction and ensure the connection between the side wall connecting member and the I-shaped supporting member in the horizontal direction.

[0018] The first connecting member is a clamping groove, and the third connecting member is a clamping groove protrusion matched with the clamping groove;

[0019] Or the first connecting member is a clamping protrusion, and the third connecting member is a clamping groove matched with the clamping groove protrusion.

[0020] The second connecting member is a clamping groove, and the fourth connecting member is a clamping groove protrusion matched with the clamping groove;

[0021] Or the second connecting member is a clamping protrusion, and the fourth connecting member is a clamping groove matched with the clamping groove protrusion.

[0022] The first support rod, the longitudinal connecting rod and the second support rod are integrally formed.

[0023] Anti-slip structures are respectively arranged on the upper surface and the lower surface of the I-shaped support member.

[0024] The anti-slip structure is a plurality of inverted teeth.

[0025] The side wall connecting member comprises a side wall rod body, a third connecting member and a fourth connecting member, wherein the third connecting member and the fourth connecting member are respectively arranged at two ends of the side wall rod body and the third connecting member, the side wall rod body and the fourth connecting member are sequentially connected as a whole.

[0026] The side wall rod body is C-shaped.

[0027] The side wall rod body adopts a constant diameter design or a variable diameter design along the horizontal direction.

[0028] When the side wall rod body adopts a constant diameter design, the side wall rod body is arc-shaped;

[0029] When the side wall rod body adopts a variable diameter design, the side wall rod body has a structural design of being thin in the middle and thick on both sides.

[0030] The side wall rod body includes a middle part and a lateral connecting part, the lateral connecting part is a group, the third connecting member, the lateral connecting part, the middle part, the lateral connecting part, and the fourth connecting member are sequentially connected as a whole, and the middle part is linear or arc-shaped.

[0031] The longitudinal connecting rod is provided with a connecting channel, the first supporting rod is provided with a first channel, and the second supporting rod is provided with a second channel. The first channel on the first supporting rod, the connecting channel on the longitudinal connecting rod, and the second channel on the second supporting rod are connected in sequence, and the blood on the first supporting rod close to the inner side of the spinal canal can be drained through the first channel, the connecting channel, and the second channel in sequence.

[0032] The first channel, the connecting channel and the second channel are respectively grooves or holes.

[0033] The connecting channel is arranged in the middle of the longitudinal connecting rod and the longitudinal connecting rod is a hollow structure, the first channel and the second channel are holes respectively, and the first channel, the connecting channel and the second channel are connected in sequence;

[0034] Or the connecting channel is a groove arranged on the upper end surface or the lower end surface of the longitudinal connecting rod, the first channel and the second channel are grooves matching the connecting channel respectively, and the first channel, the connecting channel and the second channel are connected in sequence.

[0035] The thickness of the side wall connecting piece along the vertical direction is designed to be uniform;

[0036] Or the thickness of the side wall connecting member along the vertical direction is designed to be gradually changed, and the thickness of the side wall connecting member close to the second support rod gradually decreases toward the thickness of the side wall connecting member close to the first support rod.

[0037] Along the direction from the second support rod to the first support rod, the lower end surface of the side wall connector gradually rises relative to the horizontal plane and the thickness of the side wall connector gradually decreases, and the upper end surface and the lower end surface of the side wall connector can respectively fit with the bone surface of the vertebral body.

[0038] The upper end surface and the lower end surface of the bone graft cavity are respectively provided with a sealing layer which can prevent the broken bones from sliding out of the bone graft cavity. The sealing layer is a mesh structure and can prevent bone particles from being left in the spinal canal or around the nerves and avoid compressing the spinal nerves.

[0039] The sealing layer is connected to the upper end and the lower end of the I-shaped support member respectively;

[0040] Or the sealing layer is respectively connected to the upper end and the lower end of the opening side of the side wall connecting piece.

[0041] Preferably, the sealing layer is connected to the upper end and the lower end of the I-shaped support member respectively, and the opening side of the side wall connecting member is provided with a connecting groove matching with the sealing layer;

[0042] Or the sealing layer is respectively connected to the upper end and the lower end of the opening side of the side wall connecting member, and the I-shaped supporting member is provided with a connecting groove matching the sealing layer.

[0043] like Figure 8As shown, it gives a schematic diagram of the structure of an existing intervertebral fusion device; a bone graft cavity is provided in the middle of the structure, and the four sides of the bone graft cavity all play a supporting role, especially along the insertion direction of the intervertebral fusion device, and support walls are provided on both sides of the bone graft cavity to play a supporting role. To this end, the present application has made a completely new design for the vertebral structure. The cervical intervertebral fusion device of the present application adopts a detachable structural design, which includes an I-shaped support member and a side wall connector. Among them, the I-shaped support member includes a first support rod, a second support rod, and a longitudinal connecting rod, and the two ends of the longitudinal connecting rod are respectively connected to the first support rod and the second support rod as a whole, and the formed I-shaped support member is as follows Figure 2 The first support rod and the second support rod can be designed in a straight line or a curved line. Figure 2 The first support rod, the longitudinal connecting rod and the second support rod are preferably integrally formed.

[0044] In the present application, the cross-section of the side wall connector along the horizontal direction is C-shaped, and there are two side wall connectors, which can be detachably connected to the left and right ends of the I-shaped support member (along the insertion direction of the cervical intervertebral fusion device), respectively, and a bone graft cavity is formed between the I-shaped support member and the side wall connector. In the present application, the I-shaped support member and the side wall connector are detachably connected; according to the different surgical hook vertebral joints, the corresponding side wall connector can be selected for adaptation. Among them, the first support rod is respectively provided with a first connector at both ends, and the second support rod is respectively provided with a second connector at both ends; one end of the side wall connector is provided with a third connector that matches the first connector, and the other end of the side wall connector is provided with a fourth connector that matches the second connector; the side wall connector is detachably connected to the I-shaped support member through the third connector and the fourth connector at its two ends. In this structure, the first connecting member is a clamping groove, and the third connecting member is a clamping groove protrusion matched with the clamping groove; or the first connecting member is a clamping protrusion, and the third connecting member is a clamping groove matched with the clamping groove protrusion. Preferably, the second connecting member is a clamping groove, and the fourth connecting member is a clamping groove protrusion matched with the clamping groove; or the second connecting member is a clamping protrusion, and the fourth connecting member is a clamping groove matched with the clamping groove protrusion. Furthermore, the third connecting member and the fourth connecting member can limit the side wall connecting member and the I-shaped support member in the horizontal direction, and ensure the connection between the side wall connecting member and the I-shaped support member in the horizontal direction; in the present application, along the insertion direction of the cervical intervertebral fusion device, the I-shaped support member and the side wall connecting member can maintain a relatively fixed position in the horizontal direction, and the upper and lower ends of the cervical intervertebral fusion device can be limited under the action of the cervical spine, thereby effectively simplifying the structure of the cervical intervertebral fusion device and reducing the cost of the device; at the same time, due to the simplification of the upper and lower end limiting mechanisms of the cervical intervertebral fusion device, the bone graft cavity can accommodate more broken bones, which is beneficial to the treatment of patients.

[0045] Different from the existing design, the present application adopts an I-shaped support member design. Along the insertion direction of the intervertebral fusion device, the first support rod and the second support rod respectively play a supporting role, and the side wall connector plays a connecting role between the first support rod and the second support rod. At the same time, the function of the side wall connector is changed from supporting to connecting, and the role of the side wall connector is to form a bone graft cavity between the I-shaped support member.

[0046] Traditional discectomy and intervertebral bone grafting and fusion emphasize "vertebral fusion" - the bone grows and heals from the center of the upper and lower vertebrae. However, due to anatomical and physiological reasons, the distance between the upper and lower vertebrae is far, and there may be other reasons such as blood supply. The "crawling replacement healing journey" of the bone is long and arduous, and the healing time is long. Therefore, how to shorten the healing time has become an urgent problem to be solved. To this end, the structure of this application has been completely redesigned, and the bone grafting cavity of the existing intervertebral fusion device is supported on four sides, and is replaced by the I-shaped support of this application; the I-shaped support itself makes way for the uncovertebral joints on both sides of the cervical spine, and then the corresponding bone grafting can be performed; and the existence of the side wall connector is to cooperate with the I-shaped support to form a complete bone grafting cavity; only when the bone grafting cavity is formed, the making way for the uncovertebral joint is meaningful. If only a complete bone grafting cavity is formed on the I-shaped support, the simplest way is to fix the side wall connector to the I-shaped support and adopt an integrated design, which is conducive to simplifying the overall structure, shortening a generation process, and the generation cost will be reduced accordingly. However, if a design in which an I-shaped support is fixedly connected to the side wall connector is adopted, the following defects will result: 1) If the height of the side wall connector itself is reduced, the volume of the bone graft cavity will be reduced, and the amount of bone graft will be reduced eventually, and the corresponding effect will also be reduced; 2) If the height of the side wall connector itself is increased, in some cases, it will lead to an increase in the amount of cutting of the uncovertebral joint, which is essentially not conducive to the patient's recovery; 3) For different patients, it is difficult to keep the amount of cutting of the uncovertebral joints on both sides of the cervical spine consistent. Often, the amount of cutting of the uncovertebral joint on one side is large or completely removed, while the amount of cutting of the uncovertebral joint on the other side is relatively small or not removed. In this case, the design in which the I-shaped support is fixedly connected to the side wall connector cannot meet the needs at all. To this end, the present application changes the fixed connection design into a detachable structural design; the first connector and the second connector of the I-shaped support are fixed after being manufactured and formed, and can be detachably connected with the third connector and the fourth connector of the side wall connector; in this case, on the premise that the third connector and the fourth connector adopt a unified design, side wall connectors of different heights can be designed; in actual application, by selecting side wall connectors of different heights, pairing with the uncovertebral joints on both sides of the cervical spine is achieved, the corresponding requirements are met, and the integrity of the bone graft cavity is ensured.

[0047] In actual application, according to the patient's surgical situation (taking vertebral artery type cervical spondylosis caused by hyperplasia and compression of the uncovertebral joint as an example, there is no unified opinion on the current treatment method. The comprehensive treatment method of drug treatment combined with rehabilitation and physical therapy should still be the first choice. When conservative treatment is ineffective, surgical treatment can be used as appropriate. Surgical treatment methods include simple uncovertebral joint resection, uncovertebral joint resection combined with transverse foramen decompression and other surgical methods. For some suitable cases, surgical treatment is an optional and effective treatment method. After Xu Jinsong conducted a comparative study on uncovertebral joint resection and non-resection, he believed that uncovertebral joint resection and decompression can achieve good therapeutic effects and have certain clinical promotion value.), after selecting the appropriate side wall connector, a complete modular cervical interbody fusion device is formed, and then the modular cervical interbody fusion device is implanted. After the modular cervical interbody fusion device is implanted, the distraction force can keep the muscles, annulus fibrosus and anterior and posterior longitudinal ligaments of the fusion segment in a state of continuous tension, so that the fusion segment and the fusion device can achieve three-dimensional hyperstatic fixation. At the same time, the actual application results show that based on the new structural design, bone grafting of the uncovertebral joint can be achieved, which can effectively improve the fusion rate. The fusion rate of the uncovertebral joint on the bone grafting side is higher than that on the ungrafted side, which has significant progressive significance.

[0048] The cervical intervertebral fusion device of the present application is used to restore the height of the intervertebral space to restore the stress and stability of the front and middle columns of the spine, restore, maintain and stabilize the inherent physiological protrusion of the spine, expand the intervertebral foramen, and relieve the compression of the nerve roots. The restoration of the intervertebral space height can indirectly recruit the folded yellow ligament and the compressed fiber ring due to the loss of the intervertebral space height, thereby significantly improving the stenosis of the central spinal canal, increasing the anterior-posterior diameter of the spinal canal, and reducing the original intraspinal space occupation. At the same time, the present application makes full use of the natural advantages of the cervical spine, such as the close proximity of the uncovertebral joints on both sides of the human cervical spine, and the rich blood supply of the soft tissue near the uncovertebral joints. The implanted bone creeping replacement distance is short, the growth is fast, the fusion is fast, and the fusion rate is high. At the same time, based on the modular design of the I-shaped support and the side wall connector, corresponding selections can be made for different patients to ensure the best clinical effect (mainly to achieve immediate stability and high fusion after surgery, and reduce the incidence of complications) and maximum fusion.

[0049] The upper and lower end surfaces of the modular cervical intervertebral fusion device are respectively provided with anti-skid structures; the anti-skid structures can make the modular cervical intervertebral fusion device tightly connected to the vertebral body to prevent it from slipping off the vertebral body. Further, along the insertion direction of the cervical intervertebral fusion device, the upper and lower surfaces of the I-shaped support are respectively provided with anti-skid structures; preferably, the anti-skid structures can be a plurality of inverted teeth.

[0050] In the present application, the side wall connector includes a side wall rod body, a third connector, and a fourth connector. The third connector and the fourth connector are respectively arranged at the two ends of the side wall rod body, and the third connector, the side wall rod body, and the fourth connector are sequentially connected as a whole, and the side wall rod body is C-shaped. Further, the side wall rod body adopts an equal diameter design or a variable diameter design; preferably, when the side wall rod body adopts an equal diameter design, the side wall rod body is arc-shaped; when the side wall rod body adopts a variable diameter design, the side wall rod body is a structural design with a thin middle and thick sides (in the present application, since the main function of the side wall connector is to form a bone graft cavity, it itself plays a greater role in limiting the falling of broken bones in the bone graft cavity, so it is feasible to adopt a variable diameter design). As a variation, the side wall rod body includes a middle part and a lateral connecting part, and the lateral connecting part is a group. The third connecting part, the lateral connecting part, the middle part, the lateral connecting part, the fourth connecting part are sequentially connected as a whole, and the middle part is straight (such as Figure 7 as shown) or arc-shaped.

[0051] The existing cervical intervertebral fusion device has a relatively narrow structure. When it is in use, blood can seep or flow out from both sides of the cervical intervertebral fusion device. However, the two sides of the present application are wider. Under the premise of increasing the amount of bone graft, it is difficult for blood to flow out from both sides of the fusion device. Therefore, the present application improves the structure, thereby achieving drainage operation under the premise of increasing the amount of bone graft, avoiding the formation of hematoma, and compressing the spinal nerves.

[0052] In the present application, a connecting channel is provided on the longitudinal connecting rod, a first channel is provided on the first supporting rod, and a second channel is provided on the second supporting rod. The first channel on the first supporting rod, the connecting channel on the longitudinal connecting rod, and the second channel on the second supporting rod are connected in sequence, and the blood on the first supporting rod close to the inner side of the spinal canal can be drained through the first channel, the connecting channel, and the second channel in sequence. In the present application, the first channel, the connecting channel, and the second channel are respectively designed with a groove or a hole. Further, the connecting channel is arranged in the middle of the longitudinal connecting rod and the longitudinal connecting rod is a hollow structure, correspondingly, the first channel and the second channel are respectively designed with an open hole structure, and the first channel, the connecting channel, and the second channel are connected in sequence; or the connecting channel adopts a groove design, which is arranged on the upper end face or the lower end face of the longitudinal connecting rod, correspondingly, the first channel and the second channel are respectively designed with a groove matching the connecting channel, and the working surface of the first supporting rod is located on the side of the modular cervical intervertebral fusion device close to the spinal canal, and a plurality of grooves are arranged on it, and blood can be drained through the groove on the first supporting rod, the connecting channel of the longitudinal connecting rod, and the second channel on the second supporting rod. With this structure, the first channel on the first support rod cooperates with the patient's spinal canal, that is, the first channel is connected to the patient's spinal canal and incision. After surgical decompression, a small amount of bleeding may occur in the spinal canal. With this structure, drainage in the spinal canal is facilitated, and the drainage volume can be observed at the same time, to avoid the problem of spinal hematoma compressing the spinal cord and causing paralysis due to poor drainage. At the same time, grooves are made close to the direction of the spinal canal (that is, the first channel on the first support rod is designed with several grooves) and are connected to the hollow channel of the longitudinal connecting rod, all for the convenience of drainage. As an alternative, the connecting channel is arranged on the upper end face or the lower end face of the longitudinal connecting rod.

[0053] At the same time, in the present application, the first support rod is arranged on the side close to the spinal canal, and the second support rod is arranged on the side away from the spinal canal. At the same time, the side wall connector of the present application adopts an equal thickness design or a gradual design; when the thickness of the side wall connector along the vertical direction adopts a gradual design, the thickness of the side wall connector close to the second support rod gradually decreases toward the thickness of the side wall connector close to the first support rod. Preferably, along the direction from the second support rod to the first support rod, the lower end surface of the side wall connector gradually rises relative to the horizontal plane and the thickness of the side wall connector gradually decreases, so that the upper end surface and the lower end surface of the side wall connector can respectively fit tightly with the bone surface of the vertebral body.

[0054] Furthermore, the I-shaped support and side wall connector of the present application are respectively prepared by one or more of polyetheretherketone, polylactic acid (PLA), amino acid copolymer (AACP), etc. Among them, the elastic modulus of polyetheretherketone is similar to that of cortical bone, with good biocompatibility, strength and fatigue resistance comparable to those of metal materials, and can be passed through X-rays, MRI or CT examinations without artifacts; PLA is a white semi-crystalline with a melting point of 175°C to 185°C, a tensile strength of 40 to 60MPa, and an elastic modulus of 3 to 4GPa; AACP is a new type of degradable medical polymer material, composed of 6-aminocaproic acid and glycine, proline, alanine, phenylalanine, etc.; when polylactic acid and AACP are used in the present application, the assembled cervical intervertebral fusion device is an absorbable cervical intervertebral fusion device.

[0055] Furthermore, the upper and lower end surfaces of the bone graft cavity of the present application are respectively provided with a closed layer of a mesh structure. The applicant has found that making a closed layer on both sides of the bone graft cavity can prevent the broken bones from sliding out of the bone graft cavity, which is beneficial to improving the fusion rate of cervical joint bone grafting. At the same time, the closed layer of the present application adopts a mesh structure, which can prevent the bone particles from falling off without affecting the healing of the bone. In the test, it was found that the use of the present application containing a closed layer can effectively prevent the bone particles from falling off and remaining in the spinal canal or around the nerves, avoiding compression of the spinal nerves; at the same time, it can avoid the problem of insufficient bone volume in the bone graft cavity caused by the falling of bone particles, which affects the healing. The present application uses a closed layer in the bone graft cavity of the intervertebral fusion device, which is not only of great significance in ordinary lumbar fusion devices, but also has more advantages and clinical significance in the large intervertebral fusion device of the anterior thoracolumbar OLIF surgery, and can be extended to the cervical intervertebral fusion device, which has significant progressive significance. Furthermore, the closed layer is respectively connected to the upper and lower ends of the I-shaped support member. Furthermore, based on the characteristics of the I-shaped support, there are four closing layers, which are respectively arranged at the upper and lower ends of the openings on both sides of the I-shaped support. The mesh structure can be woven in different ways, as long as it can prevent bone particles from falling off, and the material selection principle does not affect bone healing. Further, the closing layer can be made of hard material or flexible material; when the closing layer is made of hard material, it is connected to the upper and lower ends of the openings on both sides of the I-shaped support, and the opening side of the side wall connector is provided with a connecting groove that matches the closing layer, and the connecting groove itself can play a guiding role; or when the closing layer is made of flexible material, the closing layer can directly match the side wall connector to form a complete bone grafting cavity to prevent the broken bones from falling off from the bone grafting cavity. As an alternative, the closing layer is respectively connected to the upper and lower ends of the opening side of the side wall connector; in the structure, by setting the side wall connector of the closing layer and the I-shaped support, a bone grafting cavity containing upper and lower closing layers is formed. Preferably, the closing layer is respectively connected to the upper and lower ends of the opening side of the side wall connecting piece, and a connecting groove matching the closing layer is provided on the I-shaped support piece; in this structure, the closing layer is made of hard material and has a certain hardness, and the side edge of the closing layer can be inserted into the connecting groove, so that the closing layer can better match with the I-shaped support piece, and the connecting groove itself plays a guiding role. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0057] Figure 1 It is a schematic diagram of the structure of the modular cervical intervertebral fusion cage in Example 1.

[0058] Figure 2 for Figure 1 Schematic diagram of the structure of the middle I-shaped support.

[0059] Figure 3 for Figure 1Schematic diagram of the three-dimensional structure state.

[0060] Figure 4 for Figure 3 Rear view of.

[0061] Figure 5 for Figure 1 Schematic diagram of the structure of the mid-diameter reducer side wall connector.

[0062] Figure 6 Based on Figure 4 Schematic diagram of an equal-diameter sidewall connector.

[0063] Figure 7 Based on Figure 5 Schematic diagram of the changes of the variable diameter side wall connecting piece.

[0064] Figure 8 It is a schematic diagram of the structure of an existing intervertebral fusion cage.

[0065] Markings in the figure: 1. I-shaped support member, 2. Side wall connecting member, 3. First support rod, 4. Second support rod, 5. Longitudinal connecting rod, 6. First connecting member, 7. Second connecting member, 8. Third connecting member, 9. Fourth connecting member, 10. Side wall rod body, 11. Middle part, 12. Side connecting part, 20. First channel, 21. Connecting channel, 22. Second channel. DETAILED DESCRIPTION

[0066] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0067] Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0068] Example 1

[0069] The cervical intervertebral fusion device of this embodiment includes an I-shaped support member and a side wall connector; wherein the I-shaped support member mainly plays a supporting function, and the side wall connector is mainly used to form a bone graft cavity. In this embodiment, the I-shaped support member includes a first support rod, a second support rod, and a longitudinal connecting rod, and the two ends of the longitudinal connecting rod are respectively connected to the first support rod and the second support rod as a whole, and the first support rod, the longitudinal connecting rod and the second support rod are connected to form an I-shaped. In order to simplify the drawings, the applicant Figure 2 In the figure, a straight line is used to represent it; in actual application, the shape and length of the first support rod and the second support rod can be changed accordingly according to actual needs. Preferably, the first support rod, the longitudinal connecting rod and the second support rod are integrally formed.

[0070] like Figure 1 As shown, the side wall connector is a group, and the cross-section of the side wall connector along the horizontal direction is C-shaped, and a bone graft cavity is formed between the I-shaped support member and the side wall connector. At the same time, the first support rod is provided with a first connector at both ends, and the second support rod is provided with a second connector at both ends; one end of the side wall connector is provided with a third connector that matches the first connector, and the other end of the side wall connector is provided with a fourth connector that matches the second connector. The side wall connector is detachably connected to the I-shaped support member through the third connector and the fourth connector at both ends. Among them, the first connector and the second connector are respectively snap-in grooves (the snap-in grooves are provided along the vertical direction, so that the snap-in groove protrusions can be snap-into the snap-in grooves along the vertical direction), and the third connector and the fourth connector are respectively snap-in groove protrusions that match the snap-in grooves. In this embodiment, the side wall connector includes a side wall rod body, a third connector, and a fourth connector. The third connector and the fourth connector are respectively arranged at the two ends of the side wall rod body, and the third connector, the side wall rod body, and the fourth connector are sequentially connected as a whole, and the side wall rod body is C-shaped. In this embodiment, the side wall rod body adopts a variable diameter design, specifically, it is thin in the middle and thick on both sides, and its wall thickness increases uniformly from the minimum value in the middle to both sides; the width of the thinnest part in the middle of the side wall rod body is 1 / 20~5 / 6 of the width of the first support rod. In this embodiment, the wall thickness and height of the side wall connector can be set as needed, thereby forming multiple groups of side wall connectors; during actual surgery, corresponding selections can be made according to the actual situation of the patient.

[0071] like Figure 1 , Figure 2 (exist Figure 1 , Figure 2 In the figure, for the convenience of viewing, the first channel, the connecting channel, and the second channel are indicated by dotted lines), the longitudinal connecting rod is provided with a connecting channel, the first support rod is provided with a first channel, and the second support rod is provided with a second channel. The first channel on the first support rod, the connecting channel on the longitudinal connecting rod, and the second channel on the second support rod are connected in sequence. In this embodiment, the I-shaped structure composed of the first support rod, the second support rod, and the longitudinal connecting rod is consistent with the position of the existing fusion device; at the same time, the first channel, the connecting channel, and the second channel respectively adopt a through-hole structure, the connecting channel is arranged in the middle of the longitudinal connecting rod, and the longitudinal connecting rod is a hollow structure. With the first support rod as the side close to the patient's spinal canal, the first channel on the first support rod, the connecting channel on the longitudinal connecting rod, and the second channel on the second support rod are connected in sequence, and the patient's spinal canal and the incision can be connected. With this structure, the first channel can be connected with the patient's spinal canal and the incision, thereby ensuring that the patient's spinal canal and the incision are unobstructed. After surgical decompression, a small amount of bleeding may occur. This structure is used to facilitate drainage and at the same time the amount of blood in the spinal canal can be observed, thus avoiding the problem of spinal cord compression and paralysis caused by intraspinal hematoma caused by poor drainage.

[0072] As an alternative, the first channel, the connecting channel, and the second channel of the present application are respectively designed with groove structures; that is, the connecting channel is a groove arranged on the upper end face or the lower end face of the longitudinal connecting rod, and the first channel and the second channel are grooves matched with the connecting channel, respectively, and the first channel, the connecting channel, and the second channel are connected in sequence. In the specific structure, a plurality of grooves are respectively arranged on the first channel, and the groove on the first channel is connected to the connecting channel, and the connecting channel is connected to the groove of the second channel, so that the oozing blood in the spinal canal can flow out through the groove on the first channel through the connecting channel and the groove on the second channel, which is convenient for the drainage in the spinal canal, and the drainage volume can be observed at the same time, so as to avoid the problem of spinal hematoma compressing the spinal cord caused by poor drainage and causing paralysis.

[0073] Actual test results show that, by using the present application, the implant bone creeping replacement distance is short, the growth is fast, the fusion is fast, and the fusion rate is high; at the same time, the modular design of the I-shaped support and the side wall connector in the present application can ensure the best clinical effect and maximum fusion.

[0074] Meanwhile, in this embodiment, the first support rod is arranged on a side close to the spinal canal, and the second support rod is arranged on a side away from the spinal canal.

[0075] Figure 6 Given Figure 5 A variation of the above, wherein the side wall connecting rods are designed with equal diameters; Figure 7 Given Figure 5 Another deformation mode, wherein the side wall rod body includes a middle part and a lateral connection part, the lateral connection part is a group, the third connection part, the lateral connection part, the middle part, the lateral connection part, and the fourth connection part are sequentially connected as a whole, and the middle part is linear. At the same time, in this embodiment, the thickness of the side wall connection part along the vertical direction adopts a gradual design, and the thickness of the side wall connection part close to the second support rod gradually decreases toward the thickness of the side wall connection part close to the first support rod; with this structure, along the direction from the second support rod to the first support rod, the lower end surface of the side wall connection part gradually rises relative to the horizontal plane and the thickness of the side wall connection part gradually decreases, so that when the fusion device is implanted, the upper end surface and the lower end surface of the side wall connection part can respectively fit with the bone surface of the patient's vertebral body. In the present application, the side wall connection part adopts a variable wall thickness design in the vertical direction, which is conducive to increasing the volume of the bone graft cavity, and the variable wall thickness design in the vertical direction is conducive to fitting with the upper and lower bone surfaces of the patient's vertebral body. At the same time, the thickness of the side wall connector in the vertical direction of this embodiment can also be designed to be uniform.

[0076] Preferably, the I-shaped support member and the side wall connector of the present application are made of polyetheretherketone. Furthermore, the upper end face and the lower end face of the modular cervical intervertebral fusion device of the present embodiment are respectively provided with anti-slip members (in the present embodiment, the anti-slip structure is a plurality of inverted teeth); adopting this structure, when the cervical intervertebral fusion device is implanted, it can prevent the cervical intervertebral fusion device from falling off.

[0077] Furthermore, the upper and lower end surfaces of the bone graft cavity of the present embodiment are respectively provided with a closed layer, and the closed layer adopts a mesh structure. In the present embodiment, the closed layer is respectively connected to the upper and lower ends of the left and right openings of the I-shaped support. In the present embodiment, fixed nets (the fixed nets are the closed layers of the present application) are respectively made on both sides of the bone graft cavity of the intervertebral fusion device to prevent the bone particles from falling off, which can effectively prevent the broken bones from sliding out of the bone graft cavity. At the same time, the closed layer of the present application adopts a mesh structure, and as long as the bone particles can be prevented from falling off, the material selection principle does not affect bone healing. The aforementioned structure can effectively prevent the broken bones from sliding out of the bone graft cavity, ensure the amount of bone grafting, and avoid the problem of insufficient bone in the bone graft cavity after the bone particles fall off, which affects the healing; the closed layer with a mesh structure is conducive to the flow of blood in the vertical direction and promotes bone healing; at the same time, the structural design of the closed layer can prevent the bone particles from falling off, remaining in the spinal canal or around the nerves, and compressing the spinal nerves. The application of this scheme in intervertebral fusion cages is not only of great significance for ordinary lumbar fusion cages, but also has more advantages and clinical significance for large intervertebral fusion cages in thoracolumbar anterior OLIF surgery. At the same time, it can be extended to cervical intervertebral fusion cages, which has significant progressive significance.

[0078] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A modular cervical intervertebral fusion cage, characterized in that: It includes an I-shaped support member and a side wall connecting member for providing a supporting function, wherein the I-shaped support member includes a first support rod, a second support rod, and a longitudinal connecting rod, wherein the first support rod is provided with a first connecting member at both ends, and the second support rod is provided with a second connecting member at both ends; The two ends of the longitudinal connecting rod are respectively connected to the first supporting rod and the second supporting rod as a whole, and the I-shaped supporting member formed by the first supporting rod, the longitudinal connecting rod and the second supporting rod is in an I-shaped shape; The side wall connector is a group, and the cross section of the side wall connector along the horizontal direction is C-shaped; one end of the side wall connector is provided with a third connector that matches the first connector, and the other end of the side wall connector is provided with a fourth connector that matches the second connector, and the side wall connector is detachably connected to the I-shaped support member through the third connector and the fourth connector at both ends thereof; A bone graft cavity is formed between the I-shaped support member and the side wall connecting member; The first connecting member is a clamping groove, and the third connecting member is a clamping protrusion matched with the clamping groove; Or the first connecting member is a clamping protrusion, and the third connecting member is a clamping groove matched with the clamping protrusion; The second connecting member is a clamping groove, and the fourth connecting member is a clamping protrusion matched with the clamping groove; Or the second connecting member is a clamping protrusion, and the fourth connecting member is a clamping groove matched with the clamping protrusion; Anti-slip structures are respectively arranged on the upper surface and the lower surface of the I-shaped support member.

2. The cervical intervertebral fusion cage according to claim 1, characterized in that: The first support rod, the longitudinal connecting rod and the second support rod are integrally formed.

3. The cervical intervertebral fusion cage according to claim 1, characterized in that: The side wall connecting member comprises a side wall rod body, a third connecting member and a fourth connecting member, wherein the third connecting member and the fourth connecting member are respectively arranged at two ends of the side wall rod body and the third connecting member, the side wall rod body and the fourth connecting member are sequentially connected as a whole.

4. The cervical intervertebral fusion cage according to claim 3, characterized in that: The side wall rod body is C-shaped.

5. The cervical intervertebral fusion cage according to claim 3, characterized in that: The side wall rod body adopts a constant diameter design or a variable diameter design along the horizontal direction.

6. The cervical intervertebral fusion cage according to any one of claims 1 to 5, characterized in that: The longitudinal connecting rod is provided with a connecting channel, the first supporting rod is provided with a first channel, and the second supporting rod is provided with a second channel. The first channel on the first supporting rod, the connecting channel on the longitudinal connecting rod, and the second channel on the second supporting rod are connected in sequence, and the blood on the first supporting rod close to the inner side of the spinal canal can be drained through the first channel, the connecting channel, and the second channel in sequence. The first channel, the connecting channel and the second channel are respectively grooves or holes.

7. The cervical intervertebral fusion cage according to claim 6, characterized in that: The connecting channel is arranged in the middle of the longitudinal connecting rod and the longitudinal connecting rod is a hollow structure, the first channel and the second channel are holes respectively, and the first channel, the connecting channel and the second channel are connected in sequence; Or the connecting channel is a groove arranged on the upper end surface or the lower end surface of the longitudinal connecting rod, the first channel and the second channel are grooves matching the connecting channel respectively, and the first channel, the connecting channel and the second channel are connected in sequence.

8. The cervical intervertebral fusion cage according to any one of claims 1 to 5, characterized in that: The thickness of the side wall connecting piece along the vertical direction is designed to be uniform; Or the thickness of the side wall connecting member along the vertical direction is designed to be gradually changed, and the thickness of the side wall connecting member close to the second support rod gradually decreases toward the thickness of the side wall connecting member close to the first support rod.

9. The cervical intervertebral fusion cage according to claim 8, characterized in that: Along the direction from the second support rod to the first support rod, the lower end surface of the side wall connector gradually rises relative to the horizontal plane and the thickness of the side wall connector gradually decreases, and the upper end surface and the lower end surface of the side wall connector can respectively fit with the bone surface of the vertebral body.

10. The cervical intervertebral fusion cage according to claim 6, characterized in that: The thickness of the side wall connecting piece along the vertical direction is designed to be uniform; Or the thickness of the side wall connecting member along the vertical direction is designed to be gradually changed, and the thickness of the side wall connecting member close to the second support rod gradually decreases toward the thickness of the side wall connecting member close to the first support rod.

11. The cervical intervertebral fusion cage according to claim 1, characterized in that: The upper end surface and the lower end surface of the bone graft cavity are respectively provided with a sealing layer which can prevent the broken bones from sliding out of the bone graft cavity. The sealing layer is a mesh structure and can prevent bone particles from being left in the spinal canal or around the nerves and avoid compressing the spinal nerves.

12. The cervical intervertebral fusion cage according to claim 11, characterized in that: The sealing layer is connected to the upper end and the lower end of the I-shaped support member respectively; Or the sealing layer is respectively connected to the upper end and the lower end of the opening side of the side wall connecting piece.

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