3D printed artificial vertebral fixation device

Abstract

The present invention relates to a spinal stabilizer, in particular to a 3D printed artificial vertebral body fixation device. The device comprises an extendable part and a 3D printed part located at both ends of the extendable part, wherein the extendable part comprises an outer sleeve and support platforms respectively located at both ends of the outer sleeve, wherein the 3D printed part is located at the outer side of the support platform and is fixedly connected to the support platform; the barrel wall of the outer sleeve comprises an outer sleeve wall and an inner sleeve wall, wherein the outer sleeve wall is polygonal, wherein the inner sleeve wall is provided with threads, wherein a plurality of long strip holes are evenly spaced on the barrel wall of the outer sleeve, and wherein the long strip holes are symmetrically arranged relative to the axis of the outer sleeve. The device adopts a modular assembly of 3D printed parts and non-3D printed parts, and develops a simple and mechanically stable extendable method, wherein both the 3D printed part and the non-3D printed part have different models, and different models can be modularly assembled, which is beneficial to saving printing materials, shortening printing time, increasing intraoperative flexibility, reducing the gap between the artificial vertebral body and the bone interface, promoting fusion, and facilitating long-term stability.

Description

Technical Field

[0001] The invention relates to a spinal stabilizer, in particular to a 3D printed artificial vertebral body fixation device. Background Art

[0002] Spinal vertebral tumors, fractures, infections and other lesions are difficult to treat in spinal surgery. The treatment level of the above diseases is an important reflection of the level of spinal surgery in each medical unit. In recent years, with the significant improvement of the level of spinal surgery in my country, the treatment of spinal vertebral tumors, fractures, infections and other lesions has also achieved rapid development. At the same time, the improvement of clinical level has also promoted the development of scientific research and innovation, especially with the application and development of 3D printing technology in various fields, it has provided new ideas and possibilities for the treatment of traditional diseases.

[0003] The surgical treatment of spinal vertebral tumors, fractures, infections and other lesions mainly involves decompression and fixation. In the decompression stage, the doctor's surgical skills are mainly used to remove tumors, diseased bones, and infected lesions, and relieve pressure on the spinal cord, nerves and other surrounding organs. This part of the surgical technology and skills are relatively mature, while the fixation stage mainly uses implants to maintain the immediate and long-term stability of the spine. Among the implants used for fixation, artificial vertebrae are more widely used. As a vertebral substitute, artificial vertebrae can restore the physiological and anatomical structure of the spine, and their effect on spinal reconstruction is more outstanding than other implants.

[0004] With the development of spinal vertebral reconstruction and fusion technology, more and more biomechanical tests and clinical applications have shown that existing artificial vertebrae still have the following defects in treatment: (1) The metal artificial vertebrae cannot form a reliable fusion with the upper and lower vertebral bones, and the interface gap between the metal and the bone cannot be eliminated, resulting in implant dislocation, sedimentation, loosening, etc., and poor long-term stability; (2) Poor matching. Due to the individual differences in diseases and bones of different patients (such as differences in tumor size and bone length), the part that needs to be reconstructed after bone resection has different sizes, requiring personalized artificial vertebrae, but the existing artificial vertebrae cannot meet individual differences. , it often happens that the artificial vertebra does not meet the patient's needs during surgery, affecting the surgical effect; (3) The length of the existing artificial vertebra is uncontrollable, and it is impossible to take into account both convenient placement and close interface contact. If the artificial vertebra is the same size as the space left after the lesion is removed, then although the interface contact between the bone and the artificial vertebra is close, it is inconvenient to place; if the artificial vertebra is smaller than the space left after the lesion is removed, it is convenient to place but there will be a gap between the interface contact between the bone and the artificial vertebra; if the artificial vertebra is slightly larger than the space left after the lesion is removed, it is conducive to close interface contact after placement but it is difficult to insert; (4) It cannot be properly expanded during surgery, so the bone and the artificial vertebra cannot be in close contact.

[0005] Some scholars have recognized the above problems and have conducted active explorations. For example, artificial vertebrae can be extended to achieve controllable vertebral length. However, most of them have the disadvantages of complex extension mechanism, low mechanical strength and poor stability. Although closer contact with the bone interface can be ensured by extending the artificial vertebrae, the compatibility between metal and bone interface is poor, and reliable fusion cannot be formed, resulting in poor long-term stability.

[0006] Some scholars consider 3D printing trabecular vertebrae to promote trabecular ingrowth and achieve long-term bone fusion, but the current technical solution requires temporary design and printing based on the patient's bone length, which is time-consuming and requires patients to wait a long time before surgery. Moreover, once printing is completed, the size is fixed and cannot be adjusted during surgery. Once the range of tumor resection during surgery exceeds expectations, the artificial vertebra and the patient will not match. At the same time, the current 3D printed trabecular vertebrae cannot be expanded or pressurized on both sides, resulting in difficulty in insertion and loose contact with the bone interface, affecting fusion.

[0007] In summary, the existing artificial vertebrae are unable to achieve differentiated manufacturing of 3D printing and non-printing modularization, unable to achieve the organic integration of 3D printing customization and flexible intraoperative extendable adjustment, and unable to organically integrate individualized and standardized manufacturing. This brings difficulties to the product registration, specification delineation, and individualized use of implants, resulting in material waste, long printing time, and loss of flexibility during surgery. Summary of the invention

[0008] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art, and proposes a 3D printed artificial vertebral body fixation device, which adopts 3D printed parts and non-3D printed parts modular assembly, and develops a simple and mechanically stable extendable method. The 3D printed part and the non-3D printed part have different models, and the different models can be modularly assembled, which is beneficial to saving printing materials, shortening printing time, increasing intraoperative flexibility, reducing the gap between the artificial vertebra and the bone interface, promoting fusion, and facilitating long-term stability.

[0009] The technical solution of the present invention is: a 3D printed artificial vertebral body fixation device, which includes an extendable part and 3D printed parts located at both ends of the extendable part, the extendable part includes an outer sleeve and support platforms located at both ends of the outer sleeve, the 3D printed part is located outside the support platform and is fixedly connected to the support platform;

[0010] The outer sleeve wall includes an outer sleeve wall and an inner sleeve wall. The outer sleeve wall is polygonal and the inner sleeve wall is provided with threads. A plurality of long strip holes are evenly spaced on the outer sleeve wall. The long strip holes are symmetrically arranged relative to the axis of the outer sleeve.

[0011] The support platform includes a platform and an inner core, the platform is fixedly connected to the 3D printed part, the middle part of one side of the platform is fixedly connected to the inner core, the two ends of the platform are symmetrically provided with platform fixing screw holes, the platform fixing screw holes are provided with internal threads, and the internal threads are meshed with the external threads of the longitudinal locking screws;

[0012] The inner core is arranged in the outer sleeve, the outer surface of the inner core is provided with a thread, the outer thread of the inner core is meshed with the inner thread of the outer sleeve, the outer threads of the two inner cores at both ends of the outer sleeve rotate in opposite directions, a plurality of locking holes are arranged on the inner core along its axial direction, the locking holes are symmetrically arranged relative to the axis of the inner core, the locking holes are provided with an internal thread, and the internal thread of the locking hole is meshed with the external thread of the transverse locking screw;

[0013] The 3D printed part includes a skeleton and a 3D printed trabecular scaffold structure filled in the skeleton. The skeleton includes a supporting and reinforcing skeleton, a chassis, a hole wall of a bone fixing screw hole and a hole wall of a platform fixing hole. The hole wall of the platform fixing hole is provided with an internal thread, and the internal thread is engaged with the external thread of a longitudinal locking screw. The longitudinal locking screw realizes a fixed connection between the supporting platform and the 3D printed part. The hole wall of the bone fixing screw hole is provided with an internal thread, and the internal thread is engaged with the external thread of a bone screw. The bone screw realizes a fixed connection between the 3D printed part and the bone.

[0014] In the present invention, the supporting reinforcement skeleton includes an annular closed skeleton and reinforcement ribs. The annular closed skeleton is arranged in parallel with the chassis. The annular closed skeleton and the chassis are connected by a number of reinforcement ribs arranged at intervals. The hole walls of the platform fixing hole are located at both ends of the chassis. One end of the hole wall of the platform fixing hole is fixedly connected to the chassis, and the other end is fixedly connected to the annular closed skeleton. The hole walls of a number of bone fixing screw holes are arranged between the two platform fixing hole walls. The hole walls of the bone fixing screw holes are inclined, one end of which is located on the side of the 3D printed part, and the other end is located on the top surface corresponding to the chassis. One end of the hole wall of the bone fixing screw hole is fixedly connected to the reinforcement rib on the side of the 3D printed part, and the other end of the hole wall of the bone fixing screw hole is fixedly connected to the end of the hole wall of the platform fixing hole.

[0015] The side of the platform in contact with the chassis is provided with several reinforcing recesses, and correspondingly, the bottom surface of the chassis is provided with several reinforcing protrusions, which are arranged corresponding to the reinforcing recesses on the platform, and the reinforcing protrusions are arranged in the reinforcing recesses, thereby enhancing the stable connection between the chassis and the platform.

[0016] The 3D printed trabecular scaffold structure is a topological microporous structure, the micropores are interconnected, the pore size of the microporous structure is 100-1200 μm, and the porosity is 40%-88%.

[0017] The middle part of the 3D printed trabecular scaffold structure may have several pores or channels for implanting allogeneic bone or autologous bone, and a corresponding channel for bone grafting is provided on the chassis. At the same time, a channel communicating with the 3D printed bone grafting channels at both ends is provided on the inner core of the support platform, which is beneficial to the integrated healing of the bone grafting material.

[0018] The bone screw comprises a bone screw head, a bone screw rod and a bone screw tail. The head of the bone screw rod is fixedly connected to the bone screw head, the bottom of the bone screw rod is fixedly connected to the bone screw tail, a bone screw mechanical thread is provided at the connection between the bone screw head and the bone screw rod, a bone screw screwdriver hole is provided on the top end face of the bone screw head, the bone screw mechanical thread is meshed with the internal threads of the bone fixation screw holes of the 3D printed parts at both ends, and the bone screw rod is provided with an external thread.

[0019] The transverse locking screw comprises a transverse locking screw rod and a transverse locking screw head. The transverse locking screw rod is provided with a transverse locking screw thread, which is meshed with the internal thread of the locking hole on the inner core, and the top end surface of the transverse locking screw head is provided with a transverse locking screw driver hole. After the transverse locking screw passes through the long strip hole of the outer sleeve and is screwed into the locking hole, the transverse locking screw head is in the long strip hole of the outer sleeve, thereby realizing the fixed connection between the outer sleeve and the support platform.

[0020] The longitudinal locking screw includes a longitudinal locking screw head and a longitudinal locking screw rod, the longitudinal locking screw rod is provided with a longitudinal locking screw thread, the longitudinal locking screw thread is meshed with the internal thread of the platform fixing screw hole on the platform and the internal thread of the platform fixing hole of the 3D printed part, the top end surface of the longitudinal locking screw rod is provided with a longitudinal locking screwdriver hole, the longitudinal locking screw thread is meshed with the internal thread of the nut. The nut and the longitudinal locking screw are used together to fix the 3D printed parts at both ends on the support platform respectively.

[0021] Beneficial effects of the present invention:

[0022] (1) The axial length is adjustable, which can increase the flexibility of use during surgery;

[0023] (2) During placement, adjust the length to be slightly shorter than the required length, and then extend it to the required length after placement to facilitate placement;

[0024] (3) After placement during surgery, the patient can continue to extend the position slightly, apply pressure to both sides, and eliminate the contact gap;

[0025] (4) The 3D printed trabecular bone scaffold structure is used at both ends, which is conducive to fusion and has good long-term stability;

[0026] (5) Only the 3D printed parts at both ends need to be printed, which reduces 3D printing consumables and has low costs;

[0027] (6) Modular assembly: 3D printed parts can also be made in advance according to the bone characteristics of the population, which is conducive to flexible assembly and use during surgery. Extendable parts can also be designed and produced in advance in different models, and different models can be modularly assembled, which is conducive to saving printing materials and shortening printing time.

[0028] (7) It is conducive to standardized production. The needs of most patients can be met by combining different models, saving the waiting time required for temporary printing before surgery with traditional technology, shortening the hospital stay, and reducing preoperative bed rest complications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 It is a three-dimensional view of the outer sleeve;

[0031] Figure 3 It is the front view of the outer sleeve;

[0032] Figure 4 It is a three-dimensional diagram of the support platform;

[0033] Figure 5 It is the main view of the support platform;

[0034] Figure 6 It is a schematic diagram of the structure of the extendable member;

[0035] Figure 7 yes Figure 6 AA direction schematic diagram;

[0036] Figure 8 It is the first stereogram of the 3D print;

[0037] Fig. 9 is the second stereogram of the 3D print;

[0038] Fig.10 It is a stereogram of the 3D printed part;

[0039] Fig.11 This is the main view of the 3D print;

[0040] Fig.12 is a schematic diagram of the structure of a bone screw;

[0041] Fig.13 is a schematic diagram of the structure of a lateral locking screw;

[0042] Fig.14 is a schematic diagram of the structure of a longitudinal locking screw;

[0043] Fig.15 It is a schematic diagram of the structure of the nut;

[0044] Fig.16 It is an exploded structural diagram of the present invention.

[0045] In the figure: 1-3D printed part, 2-extendable part, 3-outer sleeve, 4-outer wall of sleeve, 5-inner wall of sleeve, 6-long strip hole, 7-platform, 8-inner core, 9-platform fixing screw hole, 10-locking hole, 11-reinforced recess, 12-support platform, 13-transverse locking screw, 14-3D printed trabecular bone support structure, 15-chassis, 16-support and reinforced skeleton, 17-bone fixing screw hole, 18-platform fixing hole, 19-reinforced convex part, 20-bone screw head, 21-bone screw rod, 22-bone screw tail, 23-bone screw mechanical thread, 24-bone screw screwdriver hole, 25-transverse locking screw rod, 26-transverse locking screw head, 27-transverse locking screw thread, 28-transverse locking screw screwdriver hole, 29-longitudinal locking screw head, 30-longitudinal locking screw rod, 31-longitudinal locking screw thread, 32-longitudinal locking screw screwdriver hole, 33-nut. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0047] like Figure 1 and Fig.16 As shown, the 3D printed artificial vertebral body fixation device of the present invention includes an extendable member 2 and 3D printed members 1 located at both ends of the extendable member 2. Figure 6 and Figure 7 As shown, the extendable part 2 includes an outer sleeve 3 and support platforms 12 respectively located at two ends of the outer sleeve 3 , and the 3D printed part 1 is located on the outside of the support platform 12 and is fixedly connected to the support platform 12 .

[0048] like Figure 2 and Figure 3 As shown, the outer sleeve 3 is columnar, and a cavity is provided in the center of the outer sleeve 3. In this embodiment, the cavity is cylindrical, so the wall of the outer sleeve 3 includes a sleeve outer wall 4 and a sleeve inner wall 5. The sleeve outer wall 4 is polygonal, and in this embodiment, the sleeve outer wall 4 is a dodecagon, and threads are provided on the sleeve inner wall 5. A plurality of elongated holes 6 are evenly spaced on the wall of the outer sleeve 3, and the elongated holes 6 are symmetrically arranged relative to the axis of the outer sleeve 3.

[0049] like Figure 4 and Figure 5As shown, the support platform 12 includes a platform 7 and an inner core 8. The platform 7 is fixedly connected to the 3D printed part 1, and the shape of the platform 7 is the same as that of the 3D printed part 1. The middle of one side of the platform 7 is fixedly connected to the inner core 8, and the middle of the other side of the platform 7 is provided with a plurality of reinforcing recesses 11. The two ends of the platform 7 are symmetrically provided with platform fixing screw holes 9, and the platform fixing screw holes 9 are provided with internal threads, and the internal threads are engaged with the external threads of the longitudinal locking screws. After the longitudinal locking screws pass through the 3D printed part 1 and the platform 7, the support platform 12 is fixedly connected to the 3D printed part 1.

[0050] The inner core 8 is arranged in the outer sleeve 3, and the shape of the inner core 8 is the same as the shape of the inner wall of the outer sleeve. The outer surface of the inner core 8 is provided with threads, and the outer threads of the inner core 8 mesh with the inner threads of the outer sleeve 3, and the outer threads of the two inner cores 8 located at the two ends of the outer sleeve 3 rotate in opposite directions. When the outer sleeve 3 rotates, the support platforms at the two ends of the outer sleeve can move away or closer at the same time, so as to adjust the length of the artificial vertebra. The inner core 8 is provided with a plurality of locking holes 10 along its axial direction, and the locking holes 10 are provided with internal threads, and the internal threads of the locking holes 10 mesh with the external threads of the transverse locking screws 13. Figure 7 As shown, when the transverse locking screw 13 passes through the elongated hole 6 on the outer sleeve 3 and the locking hole 10 on the inner core 8, the outer sleeve 3 and the inner core 8 are fixedly connected, preventing the sleeve from rotating and locking, while fixing the length of the artificial vertebra.

[0051] like Figure 8 , Fig. 9 , Fig.10 and Fig.11 As shown, the 3D printed part 1 includes a skeleton and a 3D printed trabecular support structure 14 filled in the skeleton, the skeleton includes a supporting and reinforcing skeleton 16, a chassis 15, the hole walls of the bone fixing screw holes 17 and the hole walls of the platform fixing holes 18, wherein the supporting and reinforcing skeleton 16 includes an annular closed skeleton and reinforcing ribs arranged parallel to the chassis 15, the shape and size of the annular closed skeleton are the same as the external contour and size of the chassis 15, and a plurality of reinforcing ribs are arranged between the annular closed skeleton and the chassis 15 at intervals, and the mechanical strength of the 3D printed part 1 is improved by arranging the chassis and the reinforcing ribs.

[0052] The hole wall of the platform fixing hole 18 is located at both ends of the chassis, one end of the hole wall of the platform fixing hole is fixedly connected to the chassis 15, and the other end is fixedly connected to the annular closed skeleton. Between the two hole walls of the platform fixing hole are provided the hole walls of several bone fixing screw holes 17. In this embodiment, two hole walls of the bone fixing screw holes 17 are provided, and the hole walls of the bone fixing screw holes are arranged in an inclined manner: one end thereof is located on the side of the 3D printed part 1, and the other end is located on the top surface corresponding to the chassis, so that one end of the hole wall of the bone fixing screw hole is fixedly connected to the reinforcing rib on the side of the 3D printed part 1, and the other end of the hole wall of the bone fixing screw hole is fixedly connected to the end of the hole wall of the platform fixing hole. The hole wall of the platform fixing hole is provided with an internal thread, and the internal thread is meshed with the external thread of the longitudinal locking screw. The longitudinal locking screw passes through the platform fixing screw hole 9 on the platform 7 and the platform fixing hole 18 on the chassis 15, thereby realizing the fixed connection between the support platform 12 and the 3D printed part 1. The wall of the bone fixation screw hole is provided with an internal thread, which meshes with the external thread of the bone screw. After one end of the bone screw is driven into the bone through the bone fixation screw hole 17, a fixed connection between the 3D printed part 1 and the bone is achieved.

[0053] The bottom surface of the chassis 15 is provided with a plurality of reinforcing protrusions 19 , which are arranged corresponding to the reinforcing recesses 11 on the platform 7 . After the reinforcing protrusions 19 are arranged in the reinforcing recesses 11 , the stable connection between the chassis 15 and the platform 7 is enhanced.

[0054] The 3D printed trabecular scaffold structure 14 is a topological microporous structure, and the micropores are interconnected. The pore size of the microporous structure pores is 100 μm to 1200 μm, and the porosity is 40% to 88%. The 3D printed trabecular scaffold structure 14 is made of titanium alloy, stainless steel, nickel, cobalt alloy, ceramic, polymer material, tantalum (Ta), zirconium (Zr), niobium (Nb), polymer material, or a mixture of the above materials 3D printed, and anions, hydroxyapatite, antibacterial drugs, antitumor drugs, bone formation promoting drugs and other drugs can be carried out in the 3D printed trabecular scaffold structure 14 for local bone tissue targeted treatment. The printing method is not limited to selective laser sintering, selective laser melting, and electron beam melting technology, and can be continuously improved with the development of 3D printing technology.

[0055] Several large pores or channels may be left in the middle of the 3D printed trabecular scaffold structure 14 for implanting allogeneic bone or autologous bone, which is conducive to bone ingrowth and ultimately forms a long-term fusion of the bone and the artificial vertebral body. In the present invention, a bone grafting channel may be left in the middle of the 3D printed trabecular scaffold structure 14, and the channel may extend to the chassis and penetrate the chassis 15, that is, a channel for bone grafting is provided on the chassis 15. At the same time, a channel is also left on the inner core 8 of the support platform 12 that communicates with the 3D printed bone grafting channels at both ends, which is conducive to the integrated healing of the bone grafting material.

[0056] like Fig.12As shown, the bone screw comprises a bone screw head 20, a bone screw rod 21 and a bone screw tail 22. The head of the bone screw rod 21 is fixedly connected to the bone screw head 20, the bottom of the bone screw rod 21 is fixedly connected to the bone screw tail 22, a bone screw mechanical thread 23 is provided at the connection between the bone screw head 20 and the bone screw rod 21, a bone screw driver hole 24 is provided at the top end surface of the bone screw head 20, and the bone screw mechanical thread 23 is engaged with the internal thread of the bone fixing screw hole 17 of the 3D printed part 1 at both ends, thereby realizing the fixed connection between the bone screw and the 3D printed part 1. The bone screw rod 21 is provided with an external thread, realizing the fixed connection between the bone screw rod 21 and the bone. Therefore, the bone screw realizes the fixed connection between the 3D printed part 1 and the bone.

[0057] like Fig.13 As shown, the transverse locking screw 13 includes a transverse locking screw rod 25 and a transverse locking screw head 26. The transverse locking screw rod 25 is provided with a thread 27, and the transverse locking screw thread 27 is engaged with the internal thread of the locking hole 10 on the inner core 8. The top end surface of the transverse locking screw head 26 is provided with a transverse locking screw driver hole 28. After the transverse locking screw 13 passes through the elongated hole 6 of the outer sleeve and is screwed into the locking hole 10, the transverse locking screw head 26 is in the elongated hole 6 of the outer sleeve, thereby achieving the position fixation of the outer sleeve 3 and the support platform 12, and limiting the rotation of the outer sleeve 3.

[0058] like Fig.14 As shown, the longitudinal locking screw includes a longitudinal locking screw head 29 and a longitudinal locking screw rod 30. The longitudinal locking screw rod 30 is provided with a longitudinal locking screw thread 31. The longitudinal locking screw thread 31 is engaged with the internal thread of the platform fixing screw hole on the platform 7 and the internal thread of the platform fixing hole of the 3D printed part 1. The top end surface of the longitudinal locking screw 30 is provided with a longitudinal locking screwdriver hole 32. Fig.15 The nut 33 in the support is used, the internal thread of the nut 33 is engaged with the longitudinal locking screw thread 31, and the nut 33 and the longitudinal locking screw are used together to fix the 3D printed parts 1 at both ends on the support platform 12 respectively.

[0059] The method of using the present invention is as follows: first, the 3D printed parts 1 on both sides are fixedly connected to the two support platforms 12 respectively through longitudinal locking screws and nuts, and then the device is placed between the upper and lower vertebrae. According to the distance between the two vertebrae, the outer sleeve is rotated, and the support platforms on both sides of the outer sleeve can be moved away or closer at the same time to adjust the length of the artificial vertebrae. When the support platforms 12 on both sides are in close contact with the upper and lower vertebrae respectively and the vertebrae on both sides are supported at the same time, bone screws are screwed in to fix them. The transverse locking screws 13 are screwed into the locking holes 10 of the inner cores 8 of the support platforms on both sides through the long strip holes 6 of the outer sleeve 3. The screw heads of the transverse locking screws 13 are in the grooves of the outer sleeve 3, which can prevent the outer sleeve from rotating and locking.

[0060] The two ends of the artificial vertebral fixation device in contact with the bone are 3D printed parts 1, which are provided with a trabecular microporous structure that facilitates bone growth. Based on the patient's CT data, the modeling is completed through medical reverse engineering software such as mimics, and the contact surface and printed component shape that meet the characteristics of the bone are designed using computer digital orthopedic technology to match the human body. At the same time, different models of printed parts can also be made in advance according to the bone characteristics of the population, which is conducive to flexible assembly and use during surgery.

[0061] The extendable part in the middle of the artificial vertebral body fixation device is a non-3D printed part. It can drive the platform of the positive and negative thread structure to move to achieve the extension of the vertebral body through the rotation of the outer sleeve, and has a locking structure after extension. Both the 3D printed part and the non-3D printed part have different models, and different models can be modularly assembled, which is conducive to saving printing materials, shortening printing time, increasing intraoperative flexibility, reducing the gap between the artificial vertebral body and the bone interface, promoting fusion, and facilitating long-term stability.

Claims

1. A 3D printed artificial vertebral body fixation device, characterized in that: The invention comprises an extendable member (2) and 3D printed members (1) located at two ends of the extendable member (2), wherein the extendable member (2) comprises an outer sleeve (3) and support platforms (12) located at two ends of the outer sleeve (3), respectively, and the 3D printed member (1) is located outside the support platform (12) and is fixedly connected to the support platform (12); The wall of the outer sleeve (3) comprises a sleeve outer wall (4) and a sleeve inner wall (5), the sleeve outer wall (4) is polygonal, the sleeve inner wall (5) is provided with threads, and a plurality of elongated holes (6) are evenly spaced on the wall of the outer sleeve (3), and the elongated holes (6) are symmetrically arranged relative to the axis of the outer sleeve (3); The support platform (12) comprises a platform (7) and an inner core (8), the platform (7) is fixedly connected to the 3D printed part (1), the middle part of one side of the platform (7) is fixedly connected to the inner core (8), the two ends of the platform (7) are symmetrically provided with platform fixing screw holes (9), the platform fixing screw holes (9) are provided with internal threads, and the internal threads are meshed with the external threads of the longitudinal locking screws; The inner core (8) is arranged in the outer sleeve (3), and the outer surface of the inner core (8) is provided with a thread, and the outer thread of the inner core (8) is meshed with the inner thread of the outer sleeve (3), and the outer threads of the two inner cores (8) located at the two ends of the outer sleeve (3) rotate in opposite directions. A plurality of locking holes (10) are arranged on the inner core (8) along the axial direction thereof, and the locking holes (10) are symmetrically arranged relative to the axis of the inner core (8). The locking holes (10) are provided with an internal thread, and the internal thread of the locking hole (10) is meshed with the external thread of the transverse locking screw (13); The 3D printed part (1) comprises a skeleton and a 3D printed trabecular support structure (14) filled in the skeleton, the skeleton comprising a supporting reinforcement skeleton (16), a chassis (15), a hole wall of a bone fixing screw hole (17) and a hole wall of a platform fixing hole (18), the hole wall of the platform fixing hole is provided with an internal thread, the internal thread of which is meshed with an external thread of a longitudinal locking screw, the longitudinal locking screw realizes a fixed connection between the supporting platform (12) and the 3D printed part (1), the hole wall of the bone fixing screw hole is provided with an internal thread, the internal thread of which is meshed with an external thread of a bone screw, the bone screw realizes a fixed connection between the 3D printed part (1) and the skeleton; The support reinforcement frame (16) comprises an annular closed frame and reinforcement ribs, the annular closed frame is arranged in parallel with the chassis (15), the annular closed frame and the chassis (15) are connected by a plurality of reinforcement ribs arranged at intervals, the hole walls of the platform fixing hole (18) are located at both ends of the chassis (15), one end of the hole wall of the platform fixing hole is fixedly connected to the chassis (15), and the other end is fixedly connected to the annular closed frame, and the hole walls of a plurality of bone fixing screw holes (17) are arranged between the two hole walls of the platform fixing holes, the hole walls of the bone fixing screw holes are arranged in an inclined manner, one end of which is located on the side of the 3D printed part (1), and the other end is located on the top surface corresponding to the chassis, one end of the hole wall of the bone fixing screw hole is fixedly connected to the reinforcement rib on the side of the 3D printed part (1), and the other end of the hole wall of the bone fixing screw hole is fixedly connected to the end of the hole wall of the platform fixing hole; The side surface of the platform (7) in contact with the chassis (15) is provided with a plurality of reinforcing recesses (11), and correspondingly, a plurality of reinforcing protrusions (19) are provided on the bottom surface of the chassis (15); the reinforcing protrusions (19) are arranged corresponding to the reinforcing recesses (11) on the platform (7), and the reinforcing protrusions (19) are arranged in the reinforcing recesses (11).

2. The 3D printed artificial vertebral body fixation device according to claim 1, characterized in that: The 3D printed trabecular scaffold structure (14) is a topological microporous structure, the micropores are interconnected, the pore diameter of the microporous structure is 100-1200 μm, and the porosity is 40%-88%.

3. The 3D printed artificial vertebral body fixation device according to claim 1, characterized in that: The middle part of the 3D printed trabecular scaffold structure (14) is reserved with a hole or channel for implanting allogeneic bone or autologous bone, which passes through the corresponding bottom plate (15), the inner core (8), and the outer sleeve (3) to form a bone implantation channel that penetrates from top to bottom.

4. The 3D printed artificial vertebral body fixation device according to claim 1, characterized in that: The bone screw comprises a bone screw head (20), a bone screw rod (21) and a bone screw tail (22); the head of the bone screw rod (21) is fixedly connected to the bone screw head (20); the bottom of the bone screw rod (21) is fixedly connected to the bone screw tail (22); a bone screw mechanical thread (23) is provided at the connection between the bone screw head (20) and the bone screw rod (21); a bone screw driver hole (24) is provided at the top end surface of the bone screw head (20); the bone screw mechanical thread (23) is meshed with the internal threads of the bone fixing screw holes (17) of the 3D printed parts (1) at both ends; and the bone screw rod (21) is provided with an external thread.

5. The 3D printed artificial vertebral body fixation device according to claim 1, characterized in that: The transverse locking screw (13) comprises a transverse locking screw rod (25) and a transverse locking screw head (26); the transverse locking screw rod (25) is provided with a transverse locking screw thread (27); the transverse locking screw thread (27) is meshed with the internal thread of the locking hole (10) on the inner core (8); and the top end surface of the transverse locking screw head (26) is provided with a transverse locking screwdriver hole (28).

6. The 3D printed artificial vertebral body fixation device according to claim 1, characterized in that: The longitudinal locking screw comprises a longitudinal locking screw head (29) and a longitudinal locking screw rod (30); the longitudinal locking screw rod (30) is provided with a longitudinal locking screw thread (31); the longitudinal locking screw thread (31) is meshed with the internal thread of the platform fixing screw hole on the platform (7) and the internal thread of the platform fixing hole of the 3D printed part (1); the top end surface of the longitudinal locking screw rod (30) is provided with a longitudinal locking screwdriver hole (32); the longitudinal locking screw thread (31) is meshed with the internal thread of the nut (33).

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