Degradable magnesium alloy reinforced polymer bone fracture plate and processing method thereof

Abstract

The invention provides a degradable magnesium alloy reinforced polymer bone fracture plate and a processing method thereof, in the processing method, a degradable magnesium alloy wire is used as a reinforcement material, polyether-ether-ketone powder is used as a base material, and the degradable magnesium alloy high-strength bone fracture plate is obtained through wire weaving, die pressure forming and high-temperature sintering. The technical problems that an existing bone fracture plate is prepared by mixing carbon fiber wires and polyether-ether-ketone powder, the carbon fiber wires are evenly distributed in a polyether-ether-ketone matrix in a prepreg tape mode, the interface bonding force of the carbon fiber wires and the polyether-ether-ketone matrix is low, and when the bone fracture plate is applied to the part with high human body bearing force, the bone fracture plate is prone to being broken and layered are solved. The method can be widely applied to processing of bone fracture plates.

Description

[0001] This application is a divisional application of the patent application filed on June 24, 2024, with application number 2024108132943 and invention title "High-strength progressive bone plate and preparation method". Technical Field

[0003] This invention relates to a bone plate, and more particularly to a biodegradable magnesium alloy reinforced polymer bone plate and its processing method. Background Technology

[0005] Bone plates are commonly used devices in internal fixation surgery for fractures. They provide fixation and support to the fracture site, reduce stress on the fracture ends, and promote normal fracture healing.

[0006] Existing bone plates are typically manufactured using pure metal materials. However, due to the significant difference between the elastic modulus of metal materials and that of human cortical bone, stress shielding and other problems can easily occur during use. To address this issue, increasingly more bone plates are being prepared by mixing continuous or chopped carbon fiber materials with polyetheretherketone (PEEK) and processing them through injection molding and high-temperature pressing. In these types of bone plates, because the carbon fiber filaments are uniformly distributed in the form of pre-impregnated tape within the PEEK matrix, the interfacial bonding strength between the two is relatively low. When applied to areas of the human body subject to high stress, the bone plates are prone to technical problems such as breakage and delamination. Summary of the Invention

[0008] To address the above-mentioned technical problems, this invention provides a biodegradable magnesium alloy reinforced polymer bone plate and its processing method. In this biodegradable magnesium alloy reinforced polymer bone plate and its processing method, the density of the middle position of the bone plate is higher, and the density of the two sides gradually decreases, forming a progressive structure. The high-density structure in the center position provides high-strength support for the bone plate.

[0009] More importantly, this processing method uses a mixture of polymer fiber materials or metal materials and polyetheretherketone powder, which has a high bonding strength and can be easily applied to parts of the human body that bear high stress. The bone plate is less likely to break or delaminate.

[0010] Therefore, the technical solution of the present invention is a processing method for a biodegradable magnesium alloy reinforced polymer bone plate, the materials used including a reinforcing material and a matrix material, wherein the reinforcing material is a biodegradable magnesium alloy wire, and the matrix material is polyetheretherketone powder, and the preparation method includes the following steps: Step (1): The biodegradable magnesium alloy wire is prepared into a multi-filled porous biodegradable magnesium alloy bone plate structure skeleton by wire weaving. The diameter of the biodegradable magnesium alloy wire is 580μm-720μm, and the particle size of the polyetheretherketone powder is 430μm-590μm. The high-density reinforcing section 1 of the multi-filled porous biodegradable magnesium alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section 2 has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section 3 has a pore size of 370-550μm and a porosity of 37%-45%. Step (2): Place the prepared porous biodegradable magnesium alloy bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the porous magnesium alloy bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 26 min - 33 min. After uniform filling, the mixed material is pressurized and formed by the cavity mold. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 120MPa - 190MPa, and the holding time is 3 min - 9 min. After pressing and forming, a progressive bone plate semi-finished product is obtained. Step (3): The progressive bone plate semi-finished product is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 280℃-420℃ and the sintering time is 0.6h-1.2h. After sintering, a high-strength biodegradable progressive bone plate is obtained.

[0011] Preferably, the diameter of the biodegradable magnesium alloy wire in step (1) is 680 μm, and the particle size of the polyether ether ketone powder is 500 μm; In step (1), the high-density reinforcing section 1 has a pore size of 300 μm and a porosity of 20%, the medium-density support section 2 has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section 3 has a pore size of 500 μm and a porosity of 40%. The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes; The pressure molding method in step (2) is vacuum hot isostatic pressing, with a pressure of 150 MPa and a holding time of 5 min; The sintering method in step (3) is solid metal sintering, the sintering temperature is 330℃, and the sintering time is 1h.

[0012] A biodegradable magnesium alloy reinforced polymer bone plate prepared by the above processing method is provided with a multi-filled porous bone plate structural skeleton. The multi-filled porous bone plate structural skeleton includes a high-density reinforcing section, a medium-density supporting section and a low-density connecting section. The high-density reinforcing section is located in the middle of the multi-filled porous bone plate structural skeleton, the medium-density supporting section is located on both sides of the high-density reinforcing section, and the low-density connecting section is located on the outside of the medium-density supporting section. The skeleton of the multi-filled pore bone plate structure is formed by interwoven threads. The density of the interwoven threads is unevenly distributed, and the interwoven threads form filling pores. The size of the filling pores is also unevenly distributed. The density of the interwoven threads on the multi-filled porous bone plate structure skeleton changes gradually, and the density of the interwoven threads on the multi-filled porous bone plate structure skeleton decreases gradually along the direction of the high-density reinforcement section, the medium-density support section and the low-density connection section. The size of the filling pores on the multi-filled pore bone plate structure also changes gradually, with the size of the filling pores increasing progressively along the direction of the high-density reinforcing section, the medium-density supporting section, and the low-density connecting section. The pores are filled with polymer material, and the outer surface of the multi-pore bone plate structure is covered with a layer of polymer material. The multi-porosity bone plate structure has multiple fixing holes, which pass through the polymer material covering the outside of the multi-porosity bone plate structure. The polymer material is a mixture of biodegradable magnesium alloy wire and polyetheretherketone powder; The surface of one side of the bone plate has a concave arc surface.

[0013] Preferably, there are six fixing holes. One fixing hole is provided on each side of the high-density reinforced section, and one fixing hole is provided in the middle and near the outer side of the two medium-density support sections.

[0014] Preferably, the filling pores on the high-density reinforced section are small square filling pores; The filling pores in the middle of the medium-density support section are small square filling pores, while the filling pores on the top and bottom sides of the medium-density support section are rectangular filling pores. The filling pores in the middle of the low-density connecting section are small square filling pores, while the filling pores on the top and bottom sides of the low-density connecting section are wide square filling pores. The width of the small square filling pores in the middle position of the low-density connecting section is smaller than the width of the small square filling pores in the middle position of the medium-density support section.

[0015] Preferably, the outer surface of the bone plate is smoothly transitioned by rounded corners.

[0016] The beneficial effects of this invention are: 1. By setting three density segments on the bone plate, the actual position of the three density segments can be adjusted according to the different locations of the patient's bone injury. By adjusting the porosity and pore size of different parts of the bone plate, the biomechanical properties of the bone plate are optimized. On the one hand, the bone plate provides biomechanical internal fixation for the bone tissue at the implantation site, and on the other hand, it can ensure that the bone tissue receives sufficient stress stimulation, stimulate the self-repair function of the bone tissue, achieve mechanical compatibility between the bone plate and human bone tissue, and at the same time, save materials and reduce production costs.

[0017] The high-density reinforced section is where the bone injury is most severe and where the bone plate is under the greatest stress. The specified pore size and porosity parameters ensure that the central part of the bone plate, which is under the greatest stress, has high strength. With sufficient strength, the bone plate can provide mechanical support. If the parameters are below this range, the central part of the bone plate is prone to breakage during actual use.

[0018] The pore size and porosity specifications of the medium-density support segment can provide excellent auxiliary support to the area surrounding the bone injury site. At the same time, it can assist in the fixation of the high-density reinforcement segment, increase the stability of the high-density reinforcement segment fixation, and prevent stress interference around the bone injury site, thus preventing secondary damage.

[0019] The low-density connecting section uses a relatively large pore size and porosity because when the bone plate is under actual stress, the stress on both sides is smaller. This range matches the actual load-bearing capacity, which avoids stress shielding effect and prevents the bone plate from loosening after long-term use.

[0020] 2. The bone plate is made into a multi-filled porous bone plate structure skeleton by using a reinforcing material. Then, the multi-filled porous bone plate structure skeleton and the matrix material are uniformly filled and mixed by ultrasonic vibration. After mixing, it is pressed and formed by vacuum hot isostatic pressing or vacuum cold isostatic pressing. Finally, the formed material is placed in a high-temperature oven for sintering. It is evident that each step contributes to increasing the strength of the bone plate. After the entire process is completed, the strength of the bone plate is significantly increased. As a result, the bone plate can withstand higher load impacts during use, minimizing the risk of damage, breakage, and other quality issues. This greatly improves the overall mechanical properties of the bone plate and ensures its long-term stable use.

[0021] 3. The bone plate made from biodegradable magnesium alloy material has significant osteoinductive ability. Specifically, the bone plate uses biodegradable magnesium alloy material, which reacts with the body fluids in the human body to produce Mg ions. These ions can promote bone regeneration through three main strategies: balancing osteoblasts and osteoclasts, regulating the immune microenvironment, and promoting bone angiogenesis, thereby achieving an osteoinductive effect and effectively accelerating the recovery speed of fracture sites.

[0022] 4. This bone plate is made by using a mixture of biodegradable metal materials and medical plastics as filling material. Compared with the traditional method of using metal materials, it is lighter in overall weight. The weight reduction can significantly reduce bone loss in patients and avoid a series of chain symptoms such as osteoporosis and bone calcification. Attached Figure Description

[0024] Figure 1 This is a three-dimensional view of the finished bone plate of the present invention; Figure 2 This is another perspective view of the finished bone plate of the present invention; Figure 3 This is a three-dimensional view of the skeleton structure of the multi-filled pore bone plate of the present invention; Figure 4 This is the present invention. Figure 3 Enlarged view of point A in the middle.

[0025] Explanation of symbols in the diagram 1. High-density reinforcing section; 2. Medium-density support section; 3. Low-density connecting section; 4. Fixing hole; 5. Concave arc surface; 6. Multi-filled pore bone plate structural skeleton; 7. Rounded corner; 8. Silk thread; 9. Filling pores. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments.

[0028] pass Figures 1-4 As can be seen, the reinforced polymer bone plate has a multi-filled porous bone plate structural framework 6. The multi-filled porous bone plate structural framework 6 includes a high-density reinforcing section 1, a medium-density supporting section 2, and a low-density connecting section 3. The high-density reinforcing section 1 is located in the middle of the multi-filled porous bone plate structural framework 6, the medium-density supporting section 2 is located on both sides of the high-density reinforcing section 1, and the low-density connecting section 3 is located on the outside of the medium-density supporting section 2.

[0029] The skeleton 6 of the multi-filled pore bone plate structure is formed by interwoven silk threads 8. The density of the interwoven silk threads 8 is unevenly distributed, and the interwoven silk threads 8 form filling pores 9. The size of the filling pores 9 is also unevenly distributed.

[0030] The density of the interwoven threads 8 on the multi-filled porous bone plate structure skeleton 6 changes gradually, and the density of the interwoven threads 8 on the multi-filled porous bone plate structure skeleton 6 decreases gradually along the direction of the high-density reinforcing section 1, the medium-density supporting section 2 and the low-density connecting section 3.

[0031] The size of the filling pores 9 on the multi-filled pore bone plate structure skeleton 6 also changes gradually, with the size of the filling pores 9 increasing progressively along the direction of the high-density reinforcing section 1, the medium-density supporting section 2, and the low-density connecting section 3.

[0032] In actual use, the high-density reinforced section 1 is the location of the most severe bone damage and the location of the greatest stress on the bone plate. The specified parameters of pore size and porosity can ensure high strength in the central part of the bone plate where the stress is greatest, so as to achieve the mechanical support function of the bone plate through sufficient strength. If it is below the parameter range, the central part of the bone plate is prone to breakage during actual use.

[0033] The pore size and porosity specifications of the medium-density support segment 2 can provide excellent auxiliary support for the periphery of the bone injury site. At the same time, it can assist in the fixation of the high-density reinforcement segment 1, increase the stability of the fixation of the high-density reinforcement segment 1, and prevent stress interference around the bone injury site, thus preventing secondary damage.

[0034] The low-density connecting section 3 uses a relatively large pore size and porosity because when the bone plate is under actual stress, the stress on both sides is relatively small. This range matches the actual load-bearing capacity, which avoids stress shielding effect and prevents the bone plate from loosening after long-term use.

[0035] In summary, by setting three density segments, the actual positions of these segments can be adjusted according to the different locations of the patient's bone injury. By adjusting the porosity and pore size of different parts of the bone plate, the biomechanical properties of the bone plate can be optimized. On the one hand, the bone plate provides biomechanical internal fixation for the bone tissue at the implantation site, and on the other hand, it can ensure that the bone tissue receives sufficient stress stimulation, stimulate the self-repair function of the bone tissue, achieve mechanical compatibility between the bone plate and human bone tissue, and at the same time, save materials and reduce production costs.

[0036] The pores 9 are filled with polymer material, and the skeleton of the multi-pore bone plate structure 6 is covered with a layer of polymer material.

[0037] The multi-pore bone plate structure skeleton 6 is provided with multiple fixing holes 4, which pass through the polymer material covering the outside of the multi-pore bone plate structure skeleton 6.

[0038] The surface of one side of the bone plate is provided with a concave arc surface 5. The shape of the concave arc surface 5 can better adapt to the anatomical structure of the human skeleton, so that the bone plate can better fit the human skeleton. The curvature of the concave surface 5 is the same as the curvature of the damaged bone, which can further promote the anatomical repositioning of the bone and achieve a better fixation effect.

[0039] Multiple fixing holes 4 are respectively set at the positions of the high-density reinforcement section and the medium-density support section.

[0040] The filling pores 9 on the high-density reinforcing section 1 are small square filling pores; the filling pores 9 in the middle position on the medium-density support section 2 are small square filling pores; the filling pores 9 on the upper and lower sides of the medium-density support section are rectangular filling pores; the filling pores 9 in the middle position on the low-density connecting section 3 are small square filling pores; and the filling pores 9 on the upper and lower sides of the low-density connecting section 3 are wide square filling pores.

[0041] The width of the small square filling pores in the middle position of the low-density connecting section 3 is smaller than the width of the small square filling pores in the middle position of the medium-density support section 2.

[0042] There are six fixing holes 4. One fixing hole 4 is provided on each of the high-density reinforced section 1 near the left and right sides, and one fixing hole 4 is provided in the middle and near the outer side of the two medium-density support sections 2.

[0043] The distribution of the fixation holes 4 ensures that the bone plate is effectively fixed on both sides and in the middle, increasing the overall stability of the bone plate fixation.

[0044] Specifically, fixing holes 4 are provided on the high-density reinforcing section 1 near the left and right sides, in the middle of the two medium-density support sections 2, and near the outer side. This ensures that the high-density reinforcing section 1 and the medium-density support section 2 can be fully covered and fixed. Furthermore, since the low-density connecting section 3 mainly serves as an auxiliary fixation, the fixing holes 4 near the outer side of the medium-density support section 2 can also provide auxiliary support and fixation for the low-density connecting section 3, thereby ensuring that all positions are effectively fixed when the bone plate is fixed.

[0045] The number of fixation holes 4 should not be too many. If there are too many fixation holes 4, the number of holes drilled into the bone will be more, the area of ​​periosteal stripping will be larger, and the damage to the bone will be greater. In addition, if there are too many fixation holes 4, the distance between adjacent fixation holes 4 will be smaller, the bending amount between adjacent fixation holes 4 will be smaller, and the bone plate will not be able to fit tightly with the bone during surgery, which will cause the bone plate to compress the periosteum and is not conducive to the effective healing of the fracture site.

[0046] The diameter of the fixing hole 4 should not be less than 1 / 4 of the width of the bone plate. If the outer diameter of the fixing hole 4 is less than 1 / 4 of the width of the bone plate, the locking area of ​​the fixing screw to the bone plate will be smaller, which will lead to the bone plate not being fixed firmly, uneven stress distribution, and even secondary damage to the damaged bone.

[0047] The outer surface of the bone plate is provided with rounded corners 7. By providing rounded corners 7, damage to the bone tissue surface can be prevented after the bone plate is fixed.

[0048] A method for preparing the above-mentioned reinforced polymer bone plate includes preparing a reinforcing material and a matrix material. The reinforcing material is a polymer fiber material or a metal material, and the matrix material is a polymer material. The preparation method includes the following steps: Step (1): Prepare the reinforcing material into a multi-filled porous bone plate structure skeleton 6.

[0049] Step (2): Place the prepared multi-filled porous bone plate structure skeleton 6 and polymer material into the cavity mold respectively. Use vibration to uniformly fill the filling pores 9 of the multi-filled porous bone plate structure skeleton 6. Then, press the uniformly mixed material through the cavity mold to form a progressive bone plate semi-finished product.

[0050] Vacuum cold isostatic pressing is often used for powders that are difficult to press, such as hard metals.

[0051] Vacuum hot isostatic pressing is mainly used in the molding of high-performance powder materials, such as powder metallurgy high-temperature alloys, powder metallurgy high-speed steel, carbon materials, and ceramic materials in industrial production.

[0052] Oscillation methods include ultrasonic oscillation and mechanical oscillation. The difference between the two is that ultrasonic oscillation has higher uniformity than mechanical oscillation. When high mixing accuracy is required, ultrasonic oscillation is usually used, while mechanical oscillation is used instead.

[0053] Step (3): Place the semi-finished progressive bone plate into a high-temperature oven for sintering. After sintering, a high-strength progressive bone plate is obtained.

[0054] Example 1 When the reinforcing material is titanium alloy wire and the matrix material is polyetheretherketone powder, the preparation method includes the following steps: Step (1): The titanium alloy wire is prepared into a multi-pore titanium alloy bone plate structure skeleton by wire weaving.

[0055] The diameter of the titanium alloy wire is 460μm-520μm, and the particle size of the polyetheretherketone powder is 350μm-440μm.

[0056] The high-density reinforcing section of the multi-porosity titanium alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section has a pore size of 370-550μm and a porosity of 37%-45%.

[0057] Step (2): Place the prepared multi-filled porous titanium alloy bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the multi-filled porous titanium alloy bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 26min-33min. After uniform filling, the mixed material is pressurized and formed by the cavity mold. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 150MPa-220MPa, and the holding time is 24min-38min. After pressing and forming, the progressive bone plate semi-finished product is obtained.

[0058] Step (3): The semi-finished progressive bone plate is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 305℃-386℃ and the sintering time is 1.1h-1.7h. After sintering, a high-strength progressive bone plate is obtained.

[0059] In Example 1, the diameter of the titanium alloy wire in step (1) is 500 μm, and the particle size of the polyether ether ketone powder is 400 μm.

[0060] In step (1), the high-density reinforcing section has a pore size of 300 μm and a porosity of 20%, the medium-density support section has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section has a pore size of 500 μm and a porosity of 40%.

[0061] The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes.

[0062] The pressure molding method in step (2) is vacuum hot isostatic pressing, with a pressure of 200 MPa and a holding time of 30 min.

[0063] The sintering method in step (3) is vacuum hot isostatic pressing sintering, the sintering temperature is 345℃, and the sintering time is 1.5h.

[0064] Titanium alloy materials have excellent corrosion resistance, biocompatibility, superior mechanical properties and fatigue resistance. They also exhibit good wear resistance in composites, effectively improving the mechanical properties of polyetheretherketone materials and ensuring the strength of bone plates.

[0065] Example 2 When the reinforcing material is carbon fiber filament and the matrix material is polyetheretherketone powder, the preparation method includes the following steps: Step (1): The carbon fiber filaments are prepared into a multi-pore carbon fiber bone plate structure skeleton by filament weaving.

[0066] The diameter of the carbon fiber filament is 8μm-13μm and the number of monofilaments is 6K-12K. The particle size of the polyetheretherketone powder is 20μm-29μm.

[0067] The high-density reinforcing section of the multi-filled porous carbon fiber splint structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section has a pore size of 370-550μm and a porosity of 37%-45%.

[0068] Step (2): Place the prepared multi-filled porous carbon fiber bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the multi-filled porous carbon fiber bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 26min-33min. After uniform filling, the mixed material is pressurized and formed by the cavity mold. The pressurization method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressurization pressure is 110MPa-190MPa, and the holding time is 22min-28min. After pressurization and forming, the progressive bone plate semi-finished product is obtained.

[0069] Step (3): The semi-finished progressive bone plate is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 305℃-365℃ and the sintering time is 0.6h-1.2h. After sintering, a high-strength progressive bone plate is obtained.

[0070] Hot pressing sintering refers to the sintering process in which materials are accelerated to flow, rearrange, and densify under a certain external force (generally 10-40 MPa depending on the strength of the mold material). The temperature required for hot pressing sintering is 100-150℃ lower than that for atmospheric pressure sintering, but the driving force for hot pressing sintering is 20-100 times greater than that for atmospheric pressure sintering.

[0071] Hot pressing sintering can achieve better mechanical properties of materials, and can reduce sintering time or sintering temperature, reduce the amount of covalent ceramic sintering aids, thereby improving the high-temperature mechanical properties of materials.

[0072] The basic principle of vacuum hot isostatic pressing is to use high-pressure gas as a pressure medium to act on the material (including encapsulated powder, green body or sintered body), so that it is subjected to uniform pressure in all directions during the heating process, and the material is densified by the combined action of high temperature and high pressure.

[0073] Vacuum hot isostatic pressing (HIP) can reduce sintering temperature and shorten sintering time. At the same time, it can greatly reduce or even eliminate the use of sintering aids, improve ceramic performance and reliability, and is particularly suitable for manufacturing products with complex shapes.

[0074] Gas pressure sintering refers to applying a certain gas pressure during the high-temperature sintering process. The pressure range is usually 1-10 MPa, in order to suppress the decomposition and weight loss of the material at high temperatures, thereby increasing the sintering temperature and further promoting the densification of the material to obtain high-density products. Gas pressure sintering and vacuum hot isostatic pressing both use gas as a method to transmit pressure.

[0075] Compared with hot pressing sintering and vacuum hot isostatic pressing sintering, the biggest advantage of gas pressure sintering is that it can reduce input costs, produce products with better performance, is suitable for products with complex shapes, and can achieve mass production.

[0076] Microwave sintering is commonly used for sintering ceramic materials. It utilizes the dielectric loss of the ceramic material in the microwave electromagnetic field to bring the material to the sintering temperature, thereby achieving the sintering and densification of the ceramic.

[0077] Spark plasma sintering, also known as "plasma-activated sintering," is a novel material preparation technology that achieves material sintering through thermal effects or other field effects by directly applying a large pulse current to a mold or sample.

[0078] Spark plasma sintering can ensure uniform heating temperature, rapid heating rate, low sintering temperature, short sintering time, high production efficiency, fine and uniform product structure, maintain the natural state of raw materials, and obtain high-density materials. It is commonly used in sintering gradient materials and complex workpieces.

[0079] Solid-state metal sintering is a sintering process that uses powdered materials. These powdered materials can be molded into the desired shapes, enabling the production of complex and intricately designed parts. Furthermore, solid-state sintering can improve the mechanical properties of materials. Compared to traditional processes, solid-state sintering has a shorter cycle time, meaning the sintering process can be completed in minutes instead of hours or longer. This high productivity and rapid material development capability have led to the wider application of solid-state metal sintering.

[0080] More importantly, solid-state metal sintering can be carried out at lower temperatures compared to traditional sintering processes, which is a significant advantage as it helps to minimize energy consumption and reduce the risk of thermal damage to the sintered materials. Furthermore, solid-state metal sintering is an extremely versatile process that can be used for densification sintering of low-melting-point metals and ultra-high-temperature ceramics, and even for bonding dissimilar materials that require non-uniform temperatures. In addition, solid-state sintering can also be used to sinter porous and fully dense components, making its applications very broad.

[0081] In summary, solid-state metal sintering offers numerous advantages, including the ability to produce complex shapes, better mechanical properties, shorter sintering time, lower sintering temperature, versatility, high-precision process control, and cost-effectiveness. These advantages make solid-state sintering an ideal manufacturing method for widespread applications.

[0082] In Example 2, the carbon fiber filament in step (1) has a diameter of 10 μm and a number of 10K filaments, and the polyetheretherketone powder has a particle size of 25 μm.

[0083] In step (1), the high-density reinforcing section has a pore size of 300 μm and a porosity of 20%, the medium-density support section has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section has a pore size of 500 μm and a porosity of 40%.

[0084] The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes.

[0085] The pressure molding method in step (2) is vacuum cold isostatic pressing, with a pressure of 160 MPa and a holding time of 25 min.

[0086] The sintering method in step (3) is spark plasma sintering, the sintering temperature is 343℃, and the sintering time is 1h.

[0087] Carbon fiber materials are characterized by high strength and low modulus, which can ensure the strength of bone plates and avoid the stress shielding effect caused by the high elastic modulus of traditional metal materials.

[0088] The fixing hole 4 is manufactured by hot extrusion or thermoforming.

[0089] Existing bone plate fixation holes are usually machined. However, machining holes can disrupt the continuity of the reinforcement structure and affect the mechanical properties around the holes. Hot extrusion or thermoforming can effectively ensure the continuity of the reinforcement around the holes, thereby ensuring the mechanical properties around the holes.

[0090] The reinforcing material can also be a biodegradable metal material, including biodegradable zinc alloy wire, biodegradable zinc alloy powder, biodegradable magnesium alloy wire, or biodegradable magnesium alloy powder.

[0091] Biodegradable metal materials react with bodily fluids in the human body and are gradually corroded and degraded by the fluids. For example, when biodegradable zinc alloy wire or biodegradable magnesium alloy wire is used, magnesium ions or zinc ions are generated when the biodegradable zinc alloy wire reacts with bodily fluids. These two types of ions are released from the fixation holes of the bone plate. As the most important trace elements in bone tissue and as an indispensable active component in human biological activities, these two types of ions play an important role in bone tissue repair and can effectively accelerate the recovery speed of fracture sites.

[0092] Example 3 When the reinforcing material is titanium alloy powder and the matrix material is polyetheretherketone powder, the preparation method includes the following steps: Step (1): Titanium alloy powder is prepared into a multi-pore titanium alloy bone plate structure skeleton by 3D printing.

[0093] The particle size of titanium alloy powder is 80μm-120μm, and the particle size of polyetheretherketone powder is 120μm-290μm.

[0094] The high-density reinforcing section 1 of the multi-porosity titanium alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section 2 has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section 3 has a pore size of 370-550μm and a porosity of 37%-45%.

[0095] Step (2): Place the prepared multi-filled porous titanium alloy bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the multi-filled porous titanium alloy bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 22min-39min.

[0096] The difference between ultrasonic vibration and mechanical vibration is that ultrasonic vibration has higher uniformity than mechanical vibration. When high mixing accuracy is required, ultrasonic vibration is usually used, while mechanical vibration is used instead.

[0097] After uniform filling, the mixed material is pressurized and molded through a cavity mold. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 150MPa-260MPa and the holding time is 16min-26min. After pressing, a progressive bone plate semi-finished product is obtained.

[0098] Step (3): The progressive bone plate molding material is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 280℃-420℃ and the sintering time is 1.6 h-2.4 h. After sintering, a high-strength progressive bone plate is obtained.

[0099] In Example 3, the titanium alloy powder in step (1) has a particle size of 100 μm and the polyether ether ketone powder has a particle size of 200 μm.

[0100] In step (1), the high-density reinforcing section 1 has a pore size of 300 μm and a porosity of 20%, the medium-density support section 2 has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section 3 has a pore size of 500 μm and a porosity of 40%.

[0101] The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes.

[0102] The pressure molding method in step (2) is vacuum hot isostatic pressing, with a pressure of 200 MPa and a holding time of 20 min.

[0103] The sintering method in step (3) is vacuum hot isostatic pressing sintering, the sintering temperature is 350℃, and the sintering time is 2h.

[0104] Example 4 When the reinforcing material is biodegradable zinc alloy wire and the matrix material is polyetheretherketone powder, the preparation method includes the following steps: Step (1): The biodegradable zinc alloy wire is prepared into a multi-pore biodegradable zinc alloy bone plate structure skeleton by wire weaving.

[0105] The biodegradable zinc alloy wire has a diameter of 520μm-620μm, and the polyetheretherketone powder has a particle size of 400μm-520μm.

[0106] The high-density reinforcing section 1 of the multi-filled porous biodegradable zinc alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section 2 has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section 3 has a pore size of 370-550μm and a porosity of 37%-45%.

[0107] Step (2): Place the prepared porous biodegradable zinc alloy bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the porous zinc alloy bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 22min-32min. After uniform filling, the mixed material is pressurized and formed by the cavity mold. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 80MPa-110MPa, and the holding time is 12min-18min. After pressing and forming, the progressive bone plate semi-finished product is obtained.

[0108] Step (3): The progressive bone plate semi-finished product is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 330℃-385℃ and the sintering time is 0.8h-1.2h. After sintering, a high-strength biodegradable progressive bone plate is obtained.

[0109] In Example 4, the diameter of the biodegradable zinc alloy wire in step (1) is 560 μm, and the particle size of the polyether ether ketone powder is 450 μm.

[0110] In step (1), the high-density reinforcing section 1 has a pore size of 300 μm and a porosity of 20%, the medium-density support section 2 has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section 3 has a pore size of 500 μm and a porosity of 40%.

[0111] The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes.

[0112] The pressure molding method in step (2) is vacuum cold isostatic pressing, with a pressure of 100 MPa and a holding time of 15 min.

[0113] The sintering method in step (3) is hot pressing sintering, the sintering temperature is 350℃, and the sintering time is 1h.

[0114] Example 5 When the reinforcing material is biodegradable magnesium alloy wire and the matrix material is polyetheretherketone powder, the preparation method includes the following steps: Step (1): The biodegradable magnesium alloy wire is prepared into a multi-filled porous biodegradable magnesium alloy bone plate structure skeleton by wire weaving.

[0115] The diameter of the biodegradable magnesium alloy wire is 580μm-720μm, and the particle size of the polyetheretherketone powder is 430μm-590μm.

[0116] The high-density reinforcing section 1 of the multi-filled porous biodegradable magnesium alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section 2 has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section 3 has a pore size of 370-550μm and a porosity of 37%-45%.

[0117] Step (2): Place the prepared porous biodegradable magnesium alloy bone plate structure into a mold cavity, and then fill the mold cavity with polyetheretherketone (PEEK) powder. The filling method is to fill in equal amounts multiple times. After each filling, the PEEK powder is uniformly filled into the filling pores 9 of the porous magnesium alloy bone plate structure by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 26 min - 33 min. After uniform filling, the mixed material is pressurized and formed by the mold cavity. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 120 MPa - 190 MPa, and the holding time is 3 min - 9 min. After pressing and forming, a progressive bone plate semi-finished product is obtained. Step (3): The progressive bone plate semi-finished product is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 280℃-420℃ and the sintering time is 0.6h-1.2h. After sintering, a high-strength biodegradable progressive bone plate is obtained.

[0118] In Example 5, the diameter of the biodegradable magnesium alloy wire in step (1) is 680 μm, and the particle size of the polyether ether ketone powder is 500 μm.

[0119] In step (1), the high-density reinforcing section 1 has a pore size of 300 μm and a porosity of 20%, the medium-density support section 2 has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section 3 has a pore size of 500 μm and a porosity of 40%.

[0120] The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes.

[0121] The pressure molding method in step (2) is vacuum hot isostatic pressing, with a pressure of 150 MPa and a holding time of 5 min.

[0122] The sintering method in step (3) is solid metal sintering, the sintering temperature is 330℃, and the sintering time is 1h.

[0123] By using 3D printing or filament weaving to prepare a progressively structured multi-filled porous bone plate framework, the reinforcing material is integrated into a three-dimensional structure. This structure is stable and has high compressive strength. It effectively solves the technical problems in existing bone plates where the reinforcing material is uniformly distributed in the form of prepreg tape within the polyetheretherketone matrix. The interfacial bonding between the two is low, and when applied to parts of the human body with high stress, the bone plate is prone to breakage, delamination, and other technical issues.

[0124] The bone plate is prepared by using ordinary medical metal materials, polymer fiber materials or biodegradable metal materials to make a multi-filled porous bone plate structure skeleton. Then, the multi-filled porous bone plate structure skeleton and the matrix material are uniformly filled and mixed by ultrasonic vibration. After mixing, it is formed by isostatic pressing. Finally, the formed material is placed in a high-temperature oven for sintering.

[0125] It is evident that each step contributes to increasing the strength of the bone plate. After the entire process is completed, the strength of the bone plate is significantly enhanced. As a result, the bone plate can withstand higher load impacts during use, minimizing the risk of damage, breakage, and other quality issues. This greatly improves the overall mechanical properties of the bone plate and ensures its long-term stable use.

[0126] Furthermore, by using biodegradable metallic materials as reinforcing materials, the bone plate produced by this method exhibits significant osteoinductive ability. Specifically, the biodegradable metallic materials used in the bone plate, such as biodegradable zinc alloys and biodegradable magnesium alloys, react with bodily fluids in the human body to produce Mg ions and Zn ions. These two ions can promote bone regeneration through three main strategies: balancing osteoblasts and osteoclasts, regulating the immune microenvironment, and promoting bone angiogenesis, ultimately achieving an osteoinductive effect.

[0127] More importantly, the bone plates prepared using this method are made by mixing different types of reinforcing materials and matrix materials. For example, the reinforcing material can be biodegradable metal wire or biodegradable metal powder. Each reinforcing material and its corresponding matrix material has its own fixed preparation parameter values, such as the diameter and particle size of the reinforcing material and the particle size of the matrix material. Another example is the pore size and porosity of different density segments in the prepared multi-filled porous bone plate structure skeleton.

[0128] The selected reinforcing material and matrix material are uniformly mixed, pressurized, and sintered to obtain a high-strength progressive bone plate. The above-mentioned preparation process has strict and specific preparation parameters and processes, such as the pressurization method, the sintering method, the sintering temperature, and the sintering time. The above-mentioned preparation parameters and processes are the key to preparing the high-strength progressive bone plate material.

[0129] Secondly, this high-strength progressive bone plate is made by using a mixture of biodegradable metal materials and medical plastics as filling material. Compared with traditional bone plates made of metal materials, it is lighter in overall weight. The weight reduction can significantly reduce bone loss in patients and avoid a series of chain symptoms such as osteoporosis and bone calcification.

[0130] However, the above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A processing method for a biodegradable magnesium alloy reinforced polymer bone plate, characterized in that: The materials used include a reinforcing material and a matrix material. The reinforcing material is a biodegradable magnesium alloy wire, and the matrix material is polyetheretherketone powder. The preparation method includes the following steps: Step (1): The biodegradable magnesium alloy wire is prepared into a multi-filled porous biodegradable magnesium alloy bone plate structure skeleton by wire weaving. The diameter of the biodegradable magnesium alloy wire is 580μm-720μm, and the particle size of the polyetheretherketone powder is 430μm-590μm. The high-density reinforcing section 1 of the multi-filled porous biodegradable magnesium alloy bone plate structure has a pore size of 250μm-350μm and a porosity of 15%-25%, the medium-density support section 2 has a pore size of 370μm-450μm and a porosity of 27%-35%, and the low-density connecting section 3 has a pore size of 370-550μm and a porosity of 37%-45%. Step (2): Place the prepared porous biodegradable magnesium alloy bone plate structure skeleton into the cavity mold, and then fill the cavity mold with polyether ether ketone powder. The filling method is to fill in equal amounts multiple times. After each filling, the polyether ether ketone powder is evenly filled into the filling pores 9 of the porous magnesium alloy bone plate structure skeleton by vibration. The vibration method is mechanical vibration or ultrasonic vibration, and the vibration time is 26 min - 33 min. After uniform filling, the mixed material is pressurized and formed by the cavity mold. The pressing method is vacuum hot isostatic pressing or vacuum cold isostatic pressing. The pressure is 120 MPa - 190 MPa, and the holding time is 3 min - 9 min. After pressing and forming, a progressive bone plate semi-finished product is obtained. Step (3): The progressive bone plate semi-finished product is placed in a high-temperature oven for sintering. The sintering method is hot pressing sintering, vacuum hot isostatic pressing sintering, gas pressure sintering, microwave sintering, spark plasma sintering or solid metal sintering. The sintering temperature is 280℃-420℃ and the sintering time is 0.6h-1.2h. After sintering, a high-strength biodegradable progressive bone plate is obtained.

2. The processing method of the biodegradable magnesium alloy reinforced polymer bone plate according to claim 1, characterized in that: The biodegradable magnesium alloy wire in step (1) has a diameter of 680 μm and the polyether ether ketone powder has a particle size of 500 μm. In step (1), the high-density reinforcing section 1 has a pore size of 300 μm and a porosity of 20%, the medium-density support section 2 has a pore size of 400 μm and a porosity of 30%, and the low-density connecting section 3 has a pore size of 500 μm and a porosity of 40%. The oscillation method in step (2) is ultrasonic oscillation, and the oscillation time is 30 minutes; The pressure molding method in step (2) is vacuum hot isostatic pressing, with a pressure of 150 MPa and a holding time of 5 min; The sintering method in step (3) is solid metal sintering, the sintering temperature is 330℃, and the sintering time is 1h.

3. A biodegradable magnesium alloy reinforced polymer bone plate, characterized in that: The biodegradable magnesium alloy reinforced polymer bone plate is prepared using the processing method described in any one of claims 1 or 2. The biodegradable magnesium alloy reinforced polymer bone plate has a multi-filled porous bone plate structural skeleton, which includes a high-density reinforcing section, a medium-density supporting section, and a low-density connecting section. The high-density reinforcing section is located in the middle of the multi-filled porous bone plate structural skeleton, the medium-density supporting section is located on both sides of the high-density reinforcing section, and the low-density connecting section is located on the outside of the medium-density supporting section. The skeleton of the multi-filled pore bone plate structure is formed by interwoven threads. The density of the interwoven threads is unevenly distributed, and the interwoven threads form filling pores. The size of the filling pores is also unevenly distributed. The density of the interwoven threads on the multi-filled porous bone plate structure skeleton changes gradually, and the density of the interwoven threads on the multi-filled porous bone plate structure skeleton decreases gradually along the direction of the high-density reinforcing section, the medium-density support section and the low-density connecting section. The size of the filling pores on the multi-filled pore bone plate structure skeleton also changes gradually, and the size of the filling pores increases gradually along the direction of the high-density reinforcing section, the medium-density supporting section and the low-density connecting section. The filling pores are filled with polymer material, and the outer surface of the multi-filled pore bone plate structure skeleton is covered with a layer of polymer material. The multi-filled porous bone plate structure skeleton is provided with multiple fixing holes, and the multiple fixing holes pass through the polymer material covering the outside of the multi-filled porous bone plate structure skeleton. The polymer material is a mixture of biodegradable magnesium alloy wire and polyetheretherketone powder; The surface of one side of the bone plate is provided with a concave arc surface.

4. The biodegradable magnesium alloy reinforced polymer bone plate according to claim 3, characterized in that: The number of fixing holes is six. One fixing hole is provided on each of the high-density reinforcing sections near the left and right sides, and one fixing hole is provided in the middle and near the outer side of each of the two medium-density support sections.

5. The biodegradable magnesium alloy reinforced polymer bone plate according to claim 3, characterized in that: The filling pores on the high-density reinforced section are small square filling pores; The filling pores located in the middle of the medium-density support section are small square filling pores, and the filling pores located on the upper and lower sides of the medium-density support section are rectangular filling pores. The filling pores in the middle of the low-density connecting section are small square filling pores, and the filling pores on the upper and lower sides of the low-density connecting section are wide square filling pores. The width of the small square filling pores in the middle position of the low-density connecting section is smaller than the width of the small square filling pores in the middle position of the medium-density support section.

6. The biodegradable magnesium alloy reinforced polymer bone plate according to claim 3, characterized in that: The outer surface of the bone plates is smoothly transitioned by rounded corners.

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