LU501223B1 - Novel Motion-preserving Artificial Cervical Disc and Vertebra Complex with Anti-Dislocation Mechanism - Google Patents

Abstract

A novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism, comprising an upper endplate, a lower endplate, a bionic vertebral body and an dislocation-preventing structure, wherein the bionic vertebral body comprises a hollow vertebral body in the middle, an upper joint socket is arranged on the upper part of the vertebral body, and a lower joint socket is arranged on the lower part of the vertebral body; the upper joint socket is connected with the upper endplate through the joint structure of the upper endplate, and the lower part is connected with the lower endplate through the joint structure of the lower endplate. The invention has sufficient supporting structure, which can provide stable support after anterior cervical vertebrotomy. According to the invention, the movement of the ball joint replaces the movement of the normal cervical vertebra, so that original mobility of the cervical vertebra can be retained.

Description

DESCRIPTION Novel Motion-preserving Artificial Cervical Disc and Vertebra Complex with Anti-Dislocation Mechanism

TECHNICAL FIELD The invention relates to a novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism.

BACKGROUND With the progress of the times and the change of working behaviors, the long-term desk workers are increasingly growing year by year, and the aging trend of social population is getting worse, so the incidence of cervical spondylosis (such as cervical spondylosis, vertebral tumors, etc.) is increasing year by year. The surgical treatment of cervical spondylosis focuses on relieving compression and rebuilding the stability of the spine at the same time. Surgery needs to remove the pathological factors that cause the compression of spinal cord and nerve roots, and implant different types of spinal implants to obtain immediate stability and maintain it for a long time. At present, subtotal cervical vertebra resection and decompression combined with vertebral fusion is one of the important methods to treat cervical diseases. In this operation, the vertebral bodies and intervertebral discs are reached through the anterior cervical approach, the adjacent upper and lower vertebral bodies of the target vertebral body are expanded by a vertebral expander, the diseased intervertebral discs are removed, most of the vertebral bodies and the posterior longitudinal ligament in bilateral uncinate vertebral joints are partially removed, suitable spinal implants are implanted in the defect areas, and the anterior cervical plate is used for fixation. As a kind of fused artificial vertebral body, titanium cage has sufficient supporting strength and good biocompatibility, and is one of the commonly used implants in cervical fusion. A large number of literatures have reported that subtotal cervical vertebra resection and decompression combined with titanium cage bone graft fusion can achieve good clinical results (Moreland DB,Asch HL,Clabeaux DE,et al Anterior cervical discectomy and fusion withimplantable titanium cage initial impressions,patient outcomes and comparisonto fusion with allograft. The spine journal:official journal of the NorthAmerican (0901283 Spine Society.2004;4(2):184-191;discussion 191).

In 1969, Hamdi reported for the first time that one patient with plasmacytoma and one patient with metastatic adenocarcinoma were treated by using artificial vertebral body instead of excising vertebral body (Hamdi,F A Prosthesis for an excised [lumbar vertebra:apreliminary report.Can Med Assoc J,1969,100,12:576-80.). Since then, scholars from all over the world have conducted extensive research on artificial vertebral bodies. Artificial vertebral bodies are mainly divided into fused artificial vertebral bodies and movable artificial vertebral bodies. Fusion prosthesis is a commonly used spinal implant in clinic at present, which has the advantages of good mechanical properties and strong immediate stability, such as 3D printing titanium cage of lower cervical vertebra (He Xijing, Lu Teng, Dong Jun, etc.), a 3D printingtitanium cage of lower cervical vertebra [P]. China, CN204931903U,2016-01-06, 2016, Winged adjustable replacement system (Sun Junkai Application of adjustable replacement system with wings in fracture and dislocation of lower cervical spine [J]. Chinese Tissue Engineering Research, 2013,17(22):4025-4033.) etc. However, it was found that after the fusion artificial vertebral body was implanted, the original normal physiological mobility of the spine was lost, the internal stress of adjacent intervertebral discs increased, and the mobility of adjacent intervertebral discs increased (Dmitriev AE,Cunningham BW,Hu NB, etal Adjacent level intradiscal pressure and segmental kinematics following acervical total disc arthroplasty-An In Vitro human cadavericmodel Spine.2005; 30(10):1165-1172), (Hilibrand AS,Carlson GD,Palumbo MA, etal Radiculopathy and myelopathy at segments adjacent to the site of aprevious anterior cervical arthrodesis.J Bone Joint Surg-Am Vol.1999; 81A(4):519-528.), which will lead to degeneration of adjacent intervertebral discs and hyperosteogeny of vertebral body (Phillips FM,Reuben) Wetzel ft.Intervertebral disc degeneration adjacent to a lumbar fusion. Anexperimental rabbit model[J]. J Bone Joint Surg Br,2002,84(2):289-294.), (Hilibrand AS,Robbins M. Adjacent segment degeneration and adjacent segmentdisease:the consequences of spinal fusion ? The spine journal: official journalof the North American Spine Society.2004; 4(6Suppl):190S-194S). Some studies have found that after two years of follow-up studies, some scholars found that maintaining cervical spine movement can effectively prevent the symptomatic changes of adjacent intervertebral discs and reduce the 10901223 changes of imaging indexes of adjacent intervertebral discs (Robertson JT,Papadopoulos SM, Traynelis VC Assessment of adjacent-segment disease in patientstreated withcervical fusion or arthroplasty:a prospective 2-year study Journal ofNeurosurgery-Spine.2005 ; 3(6):417-423).

In order to keep the original physiological mobility of the spine and reduce the possibility of diseases between adjacent vertebrae, the concept of non-fusion and mobility has gradually become the mainstream. Non-fusion surgery, such as artificial disc replacement, which only removes the diseased disc and replaces it with artificial disc, is a typical representative of non-fusion surgery. However, artificial disc replacement has a narrow scope of adaptation, and it is only suitable for the treatment of diseases with single-segment and cervical physiological curvature, but not for the cases with vertebral diseases and multi-stage diseases (Sekhon LH.Cervical arthroplasty in the management of spondylotic myelopathy[J].J SpinalDisord Tech,2003,16(4):307-313). In order to solve the problems existing in non-fusion surgery, movable artificial vertebral body has become a research hotspot. At present, common movable artificial vertebral bodies include artificial disc and vertebral system (Dong,J,LU M,LU Tet al Artificial disc and vertebra system:anovel motion preservation device for cervical spinal disease after vertebralcorpectomy[J].CLINICS,2015,70(7):493-499.), artificial cervical joint complex(YU J,LIU LT,ZHAO JN.Design and preliminary biomechanical analysis ofartificial cervical joint complex[J].Arch Orthop Trauma Surg,2013,133(6):735-743.). However, these movable artificial vertebral bodies still have the following problems, such as insufficient protection of the movable articular surface and the risk of joint dislocation; the design of artificial vertebral structure has too little contact with bone, which is not conducive to the growth of bone cells; the fixed part of artificial vertebral body 1s beyond the scope of vertebral body, which may cause compression and injury of local tissues and organs.

3D printing is a processing technology based on digital models through computer-aided design, which prints and integrates the models in layers by means of laser sintering and photocuring. The advantages of 3D printing technology are that it can process complex structures, design the appearance and structure individually, and at the same time, it can save costs and improve production efficiency, and it has a broad development space in the field of 10901223 orthopedics Bose S,Vahabzadeh S,Bandyopadhyay A.Bone tissue engineering using 3Dprinting Mater Today.2013; 16(12):496-504 Therefore, applying 3D printing to the design and manufacture of spinal implants can not only customize suitable implants according to patient information, but also greatly promote the performance improvement and innovation of implants.

SUMMARY The purpose of the invention is to solve the problems in the prior art, and provide a novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism, which is bionic designed according to human data, has enough supporting function, can keep normal cervical vertebra mobility, has dislocation-preventing structure, can provide enough bone grafting space and bone contact surface, realize immediate stability after operation, and can also realize immediate reconstruction of cervical vertebra motion function after anterior approach operation, so that its mobility is highly bionic with normal cervical vertebra.

To achieve the above objective, the present invention adopts the following technical scheme: The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism comprises: an upper endplate, the bottom of which is connected with a bionic vertebral body through an upper endplate joint structure; the lower endplate, the top of which is connected with the bionic vertebral body through the joint structure of the lower endplate; the bionic vertebral body, which comprises a hollow vertebral body in the middle, wherein the upper part of the vertebral body is provided with an upper joint socket and the lower part is provided with a lower joint socket; the upper joint socket is connected with the upper endplate through the joint structure of the upper endplate, and the lower part is connected with the lower endplate through the joint structure of the lower endplate; the front and back of the vertebral body are provided with several rhombic through-holes, and the two sides are provided with bone grafting windows;

the dislocation-preventing structure, comprising upper limit teeth and a lower limit teeth 10901223 which are respectively arranged on the upper joint socket and the lower joint socket, and a plurality of first clamping grooves and second clamping grooves which are respectively arranged on the upper endplate joint structure and the lower endplate joint structure and whose numbers and positions correspond to the upper limit teeth and the lower limit teeth; the upper limit teeth are equally spaced at the upper table of the upper joint socket, and the lower limit teeth are equally spaced at the lower table of the lower joint socket; the upper endplate, the lower endplate and the bionic vertebral body are all made by 3D printing.

The invention is further improved in that: the upper endplate comprises a first platform, the front section of which 1s provided with a pair of first screw paths whose axes are parallel and which are symmetrically distributed, and the axes of the two first screw paths forms an included angle with the plane of the first platform to facilitate the fixing of screws; the upper surface of the first platform is provided with an arc support structure; the two first screw paths are opened in the front structural area of the first platform, the support structure is arranged in the rear structural area of the first platform, and the highest point of the circular arc of the support structure is located behind the first platform, and the height of the arc surface decreases smoothly around.

The lower endplate comprises a second platform, and the front section of the second platform is provided with two pairs of second screw paths with parallel axes and symmetrical distribution, and the axes of the two second screw paths forms included angles with the plane of the second platform, so as to facilitate the fixing of screws; the two second screw paths are arranged in the front structural area of the second platform.

The joint structure of the upper endplate comprises a first joint ball handle, the top of which is fixedly connected with the lower surface of the upper endplate, and the bottom of which is provided with a first joint ball which is installed in the upper joint socket;

the joint structure of the lower endplate comprises a second joint ball handle, the bottom 10901223 of which is fixedly connected with the upper surface of the lower endplate, and the top of which is provided with a second joint ball, which is installed in the lower joint socket.

The upper limit teeth are arranged at the top of the upper joint socket, the lower limit teeth is arranged at the bottom of the lower joint socket, and the free ends of the upper limit teeth and the lower limit teeth both point to the center of the joint socket; the first clamping grooves are arranged on the first joint ball at equal intervals, and the second clamping grooves are arranged on the second joint ball at equal intervals.

A support column is arranged inside the vertebral body, and the support column is an inclined cylinder, the upper surface of which is connected with the bottommost end of the upper joint socket and smoothly extends around, and the lower surface of which is connected with the topmost end of the lower joint socket and smoothly extends around.

The rhombic through-holes on the front of the vertebral body are provided with four layers, and three on each layer are staggered; there are three layers on the back, and three on each layer are staggered.

Compared with the prior art, the invention has the following beneficial effects: the invention has sufficient support structure, which can provide stable support after anterior cervical vertebrotomy; according to the invention, the movement of the ball joints replaces the movement of the normal cervical vertebra, so that the original mobility of the cervical vertebra can be retained, and the occurrence of disease in adjacent segments of the cervical vertebra caused by fusion surgery can be prevented; and moreover, the invention has a matched dislocation-preventing structure, to prevent dislocation during joint activities. In addition, the invention has a bone grafting windows and a bone grafting space, which can accelerate biological fusion and maintain long-term stability through intraoperative bone implantation. The invention has less difficulty in implantation operation, less trauma and ease of popularization. Personalized customization by 3D printing can reduce the burden of production and carrying, and provide suitable implants.

Furthermore, the upper surface support structure of the upper endplate of the invention is designed into an arc shape according to human body information data, which conforms to the concave shape of the surface of the lower cervical endplate of the human body, improves the contact area between the upper endplate and the lower surface of the upper vertebral body, 10901223 reduces the pressure on the lower surface of the cervical vertebral body, and enhances the stability.

Furthermore, the present invention can be self-fixed on the adjacent vertebral bodies without the assistance of anterior steel plates by virtue of the screw paths in the platform structures of the upper and lower endplates, moreover, the screw paths are located in the artificial vertebral body structure, which will not lead to local occupation and affect the functions of adjacent organs (such as esophagus, trachea, etc.) after fixation.

Furthermore, in the invention, the surfaces of the upper and lower joint balls are provided with clamping grooves, which are matched with the dislocation-preventing structures at the top of the upper and lower joint sockets of the vertebral body parts. The upper endplate and lower endplate are installed into the joint sockets along the clamping grooves, and endplates reach the proper position after rotating, the dislocation-preventing structure will prevent the joint balls from coming out.

Furthermore, in the invention, the two sides of the vertebral body part are provided with bone grafting windows, and the center is hollowed out, which provides space for surgical bone grafting and is beneficial to improving fusion.

Furthermore, there is a load-bearing column in the middle of the vertebral body part of the invention, which can improve the overall mechanical properties, provide enough stability, consumes fewer peripheral materials and further improve the internal bone grafting space.

Furthermore, there is the load-bearing column in the middle of the vertebral body part of the invention, the angle of which is inclined by 10° from front to back, conforming to the intervertebral angle of human cervical vertebra, which is beneficial to maintaining normal physiological structure.

BRIEF DESCRIPTION OF THE FIGURES Fig. 1 is an isometric view of the overall structure of the present invention; Fig. 2 is a schematic structural view of the upper endplate of the present invention; Fig. 3 is a front view of Fig. 2; Fig. 4 is a side view of Fig. 2; Fig. 5 is a bottom view of Fig. 2;

. . . . . . LU501223 Fig. 6 is a side view of the lower endplate of the present invention; Fig. 7 is a front view of the vertebral body part of the present invention; Fig. 8 is a side view of the vertebral body part of the present invention; Fig. 9 is a top view of the vertebral body part of the present invention; Fig. 10 1s a side half sectional view of the overall structure of the present invention; Fig. 11 is a side view of the overall structure of the present invention; Fig. 12 is a plan view of the overall structure of the present invention.

Among them: 1- upper endplate; 2- bionic vertebral body; 3- lower endplate; 4- first platform; 5- support structure; 6- first screw path; 7- first joint ball handle; 8- first joint ball; 9- first clamping groove; 10- upper joint socket; 11- upper limit tooth; 12- vertebral body; 13- support column; 14- bone grafting window; 15- lower joint socket; 16- lower limit tooth; 17- second clamping groove; 18- second platform; 19- second screw path; 20- second joint ball handle; 21- second joint ball.

DESCRIPTION OF THE INVENTION In order to make people in the technical field better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments, and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work should belong to the scope of the present invention.

In the drawings, various structural diagrams according to the disclosed embodiments of the present invention are shown. These figures are not drawn to scale, in which some details are enlarged and may be omitted for the purpose of clear expression. The shapes of various regions and layers LU501223 shown in the figure, their relative sizes and positional relationships are only exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can additionally design regions/layers with different shapes, sizes and relative positions according to actual needs.

In the context of the present disclosure, when a layer/element is said to be "on" another layer/element, the layer/element may be directly on the other layer/element, or there may be intervening layers/elements between them. In addition, if one layer/element is "above" another layer/element in one orientation, the layer/element can be "below" the other layer/element when the orientation is reversed.

It should be noted that the terms "first", "second" and so on in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or equipment containing a series of steps or units need not be limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or equipment.

The present invention will be described in further detail below with reference to the accompanying drawings: As shown in Fig. 1, the novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism in this invention comprises the upper endplate 1, the lower endplate 3, the bionic vertebral body 2, and the dislocation-preventing structure. The upper endplate 1, the lower endplate 3 and the bionic vertebral body 2 are all made by 3D printing.

The bottom of an upper endplate 1 is connected with the bionic vertebral body 2 through an upper endplate joint structure; the upper endplate 1 comprises the first platform 4, the front section of the first platform 4 is provided with a pair of first screw paths 6 whose axes are parallel and which are symmetrically distributed, and the axes of the two first screw paths 6 forms an included angle with the plane of the first platform 4 to facilitate the fixing of screws; (0901283 the upper surface of the first platform 4 is provided with the arc support structure 5. The two first screw paths 6 are placed in the front structural area of the first platform 4, the support structure 5 is arranged in the rear structural area of the first platform 4, and the highest point of the arc of the support structure 5 1s located behind the first platform 4, and the height of the arc surface decreases smoothly around. The joint structure of the upper endplate 1 comprises the first joint ball handle 7, the top of the first joint ball handle 7 is fixedly connected with the lower surface of the upper endplate 3, and the bottom of the first joint ball handle 7 is provided with the first joint ball 8 which is installed in the upper joint socket 10; The top of the lower endplate 3 is connected with the bionic vertebral body 2 through the joint structure of the lower endplate 3; the lower endplate comprises the second platform 18, and the front section of the second platform 18 is provided with two pairs of second screw paths 19 with parallel axes and symmetrical distribution, and the axes of the two second screw paths 19 forms included angles with the plane of the second platform 18, so as to facilitate the fixing of screws. The two second screw paths 19 are arranged in the front structural area of the second platform 18. The joint structure of the lower endplate comprises the second joint ball handle 20, the bottom of second joint ball handle 20 is fixedly connected with the upper surface of the lower endplate 3, and the top of second joint ball handle 20 is provided with the second joint ball 21, which is installed in the lower joint socket 10.

The bionic vertebral body 2 comprises vertebral body itself 12, wherein the upper part of the vertebral body 12 is provided with the upper joint socket 10 and the lower part is provided with the lower joint socket 15; the upper joint socket 10 is connected with the upper endplate 1 through the joint structure of the upper endplate 1, and the lower part is connected with the lower endplate 3 through the joint structure of the lower endplate 3; the front and back of the vertebral body 12 are provided with several rhombic through-holes, and the two sides are provided with bone grafting windows 14; the support column 13 is arranged inside the vertebral body 12, and the support column 13 is an inclined cylinder, the upper surface of which is connected with the bottommost end of the upper joint socket 10 and smoothly extends around, and the lower surface of which is connected with the topmost end of the lower joint socket 15 and smoothly extends around.

The dislocation-preventing structure comprises the upper limit teeth 11 and the lower 10901223 limit teeth 16 which are respectively arranged on the upper joint socket 10 and the lower joint socket 11, and a plurality of first clamping grooves 9 and second clamping grooves 17 which are respectively arranged on the upper endplate joint structure and the lower endplate joint structure and whose numbers and positions correspond to the upper limit teeth 11 and the lower limit teeth 16; the upper limit teeth 11 and the lower limit teeth 16 are equally spaced at the upper table of the joint sockets, the upper limit teeth 11 is located at the top of the upper joint socket 10, the lower limit teeth 16 1s located at the bottom of the lower joint socket 15, and the free ends of the upper limit teeth 11 and the lower limit teeth 16 both point to the center of the joint socket; the first clamping grooves 9 are arranged on the first joint ball 8 at equal intervals, and the second clamping grooves 17 are arranged on the second joint ball 21 at equal intervals.

The structural principle of the invention is as follows: The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism of the invention mainly consists of three parts: the bionic vertebral body 2, and the upper endplate 1 and the lower endplate 3 respectively connected to the bionic vertebral body 2 through the joint ball structure. The bionic vertebral body 2 consists of the upper joint socket10, the vertebral body itself 12, the lower joint socket 15 and the support column 13; the upper joint socket10 and the lower joint socket 15 both contain dislocation-preventing structures; the vertebral body 12 includes the lateral bone grafting window 14; the upper endplate 1 and the lower endplate 3 are composed of the platform, the joint ball handle and the joint ball; the first platform 4 includes the support structure 5 and a pair of first screw paths 6; the joint ball structures of the upper endplate and the lower endplate both contain clamping grooves on their surfaces.

The endplate 1 constitutes the upper surface of the novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism of the present invention. The two screw paths are symmetrically located in the front quarter structural area of the first platform 4, and their axes form a certain angle with the plane of the first platform, allowing screws to be fixed; the upper end support structure 5 is located on the upper surface of the rear 3/4 structural area of the first platform 4, taking the shape of a circular arc, and the highest point of the arc is located at the rear 4/7 of the first platform 4, and decreases forward, backward and on both sides.

The joint structure of the upper endplate consists of the cylinder, which is connected with the LU501223 center of the rear 3/4 structural area of the lower surface of the first platform 4. The joint structure of the upper endplate includes the first joint ball 8 and three first clamping grooves 9. The upper surface of the first Joint ball 8 is connected with the center of the lower surface of the first Joint ball handle 7. The three first clamping grooves 9 are all cuboid groove-like structures and distributed on the surface of the first Joint ball 8 at equal intervals.

The bionic vertebral body 2 includes the vertebral body itself 12, the top of which is provided with the upper joint socket 10, and the upper joint socket 10 is provided with three upper limit teeth 11, which are equally spaced at the upper table of the upper joint socket 10 and form an upper dislocation-preventing structure with three first clamping grooves 9. The upper joint socket 10 consists of a curved surface with a horizontal table top. The bottom of the vertebral body itself 12 is provided with the lower joint socket 15, and the lower joint socket 15 is provided with three lower limit teeth 16, which are equally spaced at the lower table of the lower joint socket 15 and form a lower dislocation-preventing structure with three second clamping grooves 17. The lower joint socket 15 consists of a curved surface with a horizontal table below.

The front of the vertebral body itself 12 consists of four layers of staggered rhombus structures, with three rhombus in each layer; the back is composed of three layers of staggered rhombus structures, with three rhombus in each layer; the lateral side is the bone grafting window 14; the vertebral body itself 12 is connected upward with the upper joint socket.

The support column 13 is arranged inside the vertebral body 12. The support column 13 is composed of the inclined cylinder, the upper surface of which is connected with the bottommost end of the upper joint socket 10 and extends around, and the lower surface of which is connected with the topmost end of the lower joint socket 15 and extends around.

The lower endplate 3 constitutes the lower surface of the novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism of the present invention. The two screw paths are symmetrically located in the front quarter of the structure area of the second platform 18, and their axes are at a certain angle with the plane of the second platform 18, allowing screws to be fixed.

The joint structure of the lower endplate consists of a cylinder, which is connected with the center of the rear 3/4 structural area of the upper surface of the second platform 18. The lower endplate joint structure includes the second joint ball 21 and three second clamping grooves 17, and the lower LU501223 surface of the second joint ball 21 is connected with the center of the lower surface of the second joint ball handle 20. The three second clamping grooves 17 are all cuboid groove-like structures and distributed on the surface of the second joint ball 21 at equal intervals.

The joint ball structure of that present invention include the joint ball structures of the upper and low endplates, and the upper and lower joint sockets adapt to the joint balls at the upper and lower ends of the bionic vertebral body 2, wherein the inner space of the joint sockets consists of hemispheres with two sides intersecting, the upper and lower limit teeth of the dislocation-preventing structure are respectively arranged at the top and bottom of the hemispheres, and the first and second joint balls are wrapped in the corresponding hemispheres, and their removal is restricted by the cooperation of the clamping grooves on the surface of the joint balls and the limit teeth.

Example: Referring to Fig. 1, Fig. 10, Fig. 11 and Fig. 12, in this embodiment, the 3D printing bionic dislocation-preventing cervical vertebra movable artificial vertebral body has a front edge height of 23 mm, a rear edge height of 21 mm, a vertical maximum height of 25 mm along the support structure 5, the highest point of the upper part is located at the rear 3/7, gradually decreasing to both sides, and the lowest point of the lower part is located at the forefront, with a front-back diameter length of 15 mm and a left-right diameter of 13 mm.

As shown in Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 10, in this embodiment, the first platform 4 has a height of 2 mm, a front-back length of 15 mm or so and a left-right width of 13 mm; the support structure 5 is located at the back and upper part of the first platform 4, with a circular arc shape, the highest point at the back 4/7, and the height of 1.3 mm, which decreases forward, backward and on both sides; the two first screw paths 6 are cylindrical with a diameter of 3 mm, symmetrically located in the front quarter structural area of the first platform 4, and their axes make an angle of 40 degrees with the plane, allowing screws to be fixed. The first joint ball handle 7 is a cylinder with a diameter of 7 mm and a height of 3 mm, and is connected with the rear 3/4 structural area of the lower surface of the first platform 4. The first joint ball 8 has a diameter of 9 mm and a height of 2.5 mm, and is connected with the lower surface of the first joint ball handle 7. The three first clamping grooves 9 are cuboid groove-like structures with a length of 1 mm, a width of 0.75 mm and a height of 2.5 mm, and are distributed on the surface of the first joint ball 8 at intervals of 60 degrees. The support structure 5 is configured to fit with the curved surface of the lower endplate of the upper vertebral body, increase LU501223 the contact area and reduce the pressure under the cervical vertebral body, thus effectively preventing bone destruction. The first screw paths 6 are arranged on the first platform 4 of the upper endplate 1, which adopts the self-fixed mode, and no additional steel plate is needed for fixing, thereby reducing the damage to surrounding tissues. The first clamping grooves 9 are adapted to the dislocation-preventing structure, and is a combined installation channel of the upper endplate 1 and the bionic vertebral body 2.

As shown in Fig. 2, Fig. 3, Fig.4, Fig.5, Fig. 6 and Fig. 10, in this embodiment, the second platform 18 has a height of 2 mm, a front-back length of 15 mm or so and a left-right width of 13 mm; the two second screw paths 19 are cylindrical with a diameter of 3 mm, symmetrically located in the front quarter of the second platform 18, and their axes form an angle of 40 degrees with the plane, allowing screws to be fixed. The second joint ball handle 20 is a cylinder with a diameter of 7 mm and a height of 3 mm, and is connected with the rear 3/4 structural area of the upper surface of the second platform 18. The second joint ball 21 has a diameter of 9 mm and a height of 2.5 mm, and is connected with the upper surface of the second joint ball handle 20. The three second grooves 17 are cuboid groove-like structures with a length of 0.75 mm, a width of 0.5 mm and a height of 2.5 mm, and are distributed on the surface of the second joint ball 21 at intervals of 60 degrees. The second screw paths 19 is located in the second platform 18 of the upper endplate 1, which belongs to the self-fixed mode, and no additional steel plate is needed to fix it, thus reducing the damage to surrounding tissues. The second clamping grooves 17 are adapted to the dislocation-preventing structure, and is a combined installation channel of the lower endplate 3 and the bionic vertebral body 2.

As shown in Fig. 2, Fig. 6, Fig. 7, Fig. 8, Fig. 9 and Fig. 10, in this embodiment, both the upper joint socket 10 and the lower joint socket 15 are made of the same curved surface as the joint balls, with a thickness of 1 mm and a horizontal upper part. The dislocation-preventing structure consists of three cubes with a side length of 1 mm, with a distance of 60 distributed at the upper table of the arc surface of the joint socket and a distance of Imm from the joint ball. The vertebral body 12 has a front edge height of 15 mm, a rear edge height of 12 mm, a front-back length of 9 mm, and a left-right width of 10 mm. The front of the vertebral body 12 is composed of four layers of staggered rhombic structures, with three rhombuses in each layer. The back is composed of three layers of staggered rhombus structures, with three rhombuses in each layer; each side has a bone grafting window 14. The dislocation-preventing structure is matched with the first clamping grooves 9 to prevent the upper LU501223 endplate 1 and the lower endplate 3 from falling out of the corresponding joint socket after installation.

The vertebral body 12 has a hollow design, which increases the contact area between the internal bone graft particles and the surrounding bone, which is beneficial to the early fusion of bone in the operation area and improves the long-term stability. The bone grafting window 14 has a large aperture, which is beneficial to the operation of bone implantation during operation. The support columns 13 are inclined cylinders with a diameter of 4 mm, which are respectively connected with the top arc surface of the upper joint socket10 and the bottom arc surface of the lower joint socket 15. The vertebral body 12 and the support column 13 can be adjusted according to different personal imaging data.

As shown in Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 9 and Fig. 10, the inner space of the first joint socket 10 and the second joint socket 15 is large enough to allow the first joint socket 8 and the second joint socket 21 to move. The upper endplate 1 is taken as an example to show the way of installation. Specifically, the first clamping grooves 9 are aligned with the upper limit teeth 11 on the first joint socket 10, and installed along the first clamping grooves 9, and then the upper endplate 1 is rotated by 60 degrees to reach the required standard position, as shown in Fig. 1. The first joint ball 8 is wrapped in the second joint socket 10, which is restricted by the dislocation-preventing structure, preventing the artificial vertebral endplate from falling out, and reserving enough space for moving. The installation process of lower endplate 3 is the same as that of upper endplate 1.

Because the height of cervical vertebra is different among people, five different models are designed according to imaging data to meet the needs of different implant heights, namely the largest, large, standard, small and smallest models. The standard model is the same as that of above-mentioned embodiment, and the maximum model is to lengthen the vertebral body itself 12 and the support column 13 by 2 mm on the basis of the standard model. The large model is to lengthen the vertebral body itself 12 and the support column 13 by 1 mm on the basis of the standard model. The small model is based on the standard model, with the vertebral body 12 and the support column 13 being reduced by 1 mm. The smallest model is to shorten the vertebral body 12 and the support column 13 by 2 mm on the basis of the standard model.

To sum up, the novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism of the present invention is suitable for diseases requiring subtotal cervical vertebra decompression combined with implant fusion, especially for cervical vertebra diseases with single vertebral body and two spaces, such as cervical spondylosis caused by protrusion LU501223 of two cervical intervertebral discs, tumor of single cervical vertebra body, revision after artificial cervical intervertebral disc replacement, etc.

The concrete implementation of discectomy, subtotal corpectomy, this the novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism implantation will be described as follows.

For patients with indications, the preoperative examination should be adequate, and patients without contraindications should undergo preoperative exercises such as defecation and urination in bed before the operation. Patients are placed in supine position, with soft pillows under their shoulders, soft head rings on their back pillows and small sandbags on both sides of their heads. Routine preoperative preparation is carried out, endotracheal intubation is adopted for general anesthesia, neck disinfection and surgical towel spreading are done. Anterior transverse incision is used to separate soft tissue layer by layer, and the trachea and esophagus are protected by retractor. The target vertebral body are exposed, the positioning needle is installed, and the C-arm X-ray fluoroscope is used to locate and confirm the target vertebral body. Cervical vertebra distractor screws are installed in the upper and lower vertebral bodies of the target vertebral body, and the distractor distracts. The fibrous ring of the intervertebral disc above and below the target vertebral body is cut off, and the intervertebral disc tissue is taken out with nucleus pulposus forceps. The osteotome is used to remove the anterior bone of vertebral body, and the curette, rongeur and round-headed file are used to repair the intervertebral joint surface, but do not destroy the bone endplate. The gap between the posterior edge of the vertebral body and the posterior longitudinal ligament is separated with a nerve stripper, and the cortical bone of the posterior edge of the vertebral body and ossified posterior longitudinal ligament are removed with the rongeur. forming a rectangular decompression slot with a width of approximately 13 mm is done for decompression. The joint complex in this invention with proper height is selected, vertebral body bone is cut to pieces with a size of about 2 mm, and the internal hollow structure is put in from the bone grafting windows on both sides of the artificial vertebral body. The upper and lower endplates are installed, the angle is adjusted to prevent them from falling out, and put into this complex, so that the upper endplate is attached to the lower endplate of the upper vertebral body, and the lower endplate is attached to the upper endplate of the lower vertebral body. Two fixation screws for vertebral body are screwed on, upper and lower, to fix the complex. The vertebral distractor is loosened to make this complex embedded tightly. C-arm X-ray machine 0501223 fluoroscopy confirms the position of the implant, the wound 1s subject to normal saline, drainage 1s placed and sutures layer by layer are carried out. Routine nursing after operation is done, one day later, the drainage is removed, and the Orthosis Cervical is worn for three months.

The above content is only to illustrate the technical idea of the present invention, and can't be used to limit the scope of protection of the present invention. Any changes made on the basis of the technical scheme according to the technical idea put forward by the present invention fall within the scope of protection of the claims of the present invention.

Claims (9)

CLAIMS LU501223

1. A novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism, characterized by comprising: an upper endplate (1), the bottom of the upper endplate (1) is connected with a bionic vertebral body (2) through an upper endplate joint structure; a lower endplate (3), the top of the lower endplate (3) is connected with the bionic vertebral body (2) through the joint structure of the lower endplate (3); the bionic vertebral body (2), comprising a hollow vertebral body itself (12) in the middle, wherein the upper part of the vertebral body (12) is provided with an upper joint socket (10) and the lower part is provided with a lower joint socket (15); the upper joint socket (10) is connected with the upper endplate (1) through the joint structure of the upper endplate, and the lower part is connected with the lower endplate (3) through the joint structure of the lower endplate; the front and back of the vertebral body itself (12) are provided with several rhombic through-holes, and the two sides of the vertebral body itself (12) are provided with bone grafting windows (14); a dislocation-preventing structure, comprising upper limit teeth (11) and a lower limit teeth (16) which are respectively arranged on the upper joint socket (10) and the lower joint socket (15), and a plurality of first clamping grooves (9) and second clamping grooves (17) which are respectively arranged on the upper endplate joint structure and the lower endplate joint structure and whose numbers and positions correspond to the upper limit teeth (11) and the lower limit teeth (16); the upper limit teeth (11) are equally spaced at the upper table of the upper joint socket (10), and the lower limit teeth (16) are equally spaced at the lower table of the lower joint socket (15); the upper endplate (1), the lower endplate (3) and the bionic vertebral body are all made by 3D printing.

2. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 1, characterized in that the upper endplate (1) comprises a first platform (4), wherein the front section of first platform (4) is provided with a pair of first screw paths (6) whose axes are parallel and which are symmetrically distributed, and the axes of the two first screw paths (6) forms an included angle with the plane of the first platform (4) to facilitate the fixing of screws and the upper surface of the first platform (4) is 10901223 provided with an arc support structure (5).

3. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 2, characterized in that the two first screw paths (6) are positioned in the front structural area of the first platform (4), the support structure (5) is arranged in the rear structural area of the first platform (4), and the highest point of the circular arc of the support structure (5) is located behind the first platform (4), and the height of the arc surface decreases smoothly around.

4. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 1, characterized in that the lower endplate (3) comprises a second platform (18), and the front section of the second platform (18) is provided with two pairs of second screw paths (19) with parallel axes and symmetrical distribution, and the axes of the two second screw paths (19) form included angles with the plane of the second platform (18), so as to facilitate the fixing of screws.

5. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 4, characterized in that the two second screw paths (19) are arranged in the front structural area of the second platform (18).

6. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 1, characterized in that the joint structure of the upper endplate comprises a first joint ball handle (7), the top of the first joint ball handle (7) 1s fixedly connected with the lower surface of the upper endplate (1), and the bottom of first joint ball handle (7) 1s provided with a first joint ball (8) which 1s installed in the upper joint socket (10); the joint structure of the lower endplate comprises a second joint ball handle (20), the bottom of second joint ball handle (20) is fixedly connected with the upper surface of the lower endplate (3), and the top of second joint ball handle (20) is provided with a second joint ball (21), which is installed in the lower joint socket (15).

7. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 6, characterized in that the upper limit teeth (11) are arranged at the top of the upper joint socket (10), the lower limit teeth (16) is arranged at the bottom of the lower joint socket (15), and the free ends of the upper limit teeth 10901223 (11) and the lower limit teeth (16) both point to the center of the joint socket, the first clamping grooves (9) are arranged on the first joint ball (8) at equal intervals, and the second clamping grooves (17) are arranged on the second joint ball (21) at equal intervals.

8. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 1, characterized in that a support column (13) is arranged inside the vertebral body, and the support column (13) is an inclined cylinder, the upper surface of the support column (13) is connected with the bottommost end of the upper joint socket (10) and smoothly extends around, and the lower surface of the support column (13) is connected with the topmost end of the lower joint socket (15) and smoothly extends around.

9. The novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism according to claim 1, characterized in that the rhombic through-holes on the front of the vertebral body itself (12) are provided with four layers, and three on each layer are staggered; there are three layers on the back, and three on each layer are staggered.