Manufacturing process of knee joint revision prosthesis

Abstract

The invention discloses a knee joint revision prosthesis manufacturing process, and relates to the technical field of knee joint prosthesis manufacturing, the knee joint revision prosthesis manufacturing process comprises a demolding frame, a first mold is arranged on the inner wall of one side of the demolding frame, a second mold is arranged on the upper left portion of the first mold, and a third mold is arranged on the lower left portion of the first mold; a prosthesis and a filling block are arranged in a gap among the second mold, the third mold and the first mold, the filling block is inserted into the top of the second mold, and a temperature sensor is fixedly mounted at the top of the filling block. According to the non-contact demolding device, the split type molds (the first mold, the second mold and the third mold) and the demolding assembly work cooperatively, the second mold and the third mold are controlled to be separated from the two sides of the prosthesis through the first electric push rod, then the second electric push rod is used for pushing the folding top plate to enable the first mold to deform moderately, and non-contact demolding of the arc-shaped prosthesis is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of knee joint prosthesis manufacturing, in particular to a manufacturing process of knee joint revision prosthesis. BACKGROUND

[0002] The knee joint prosthesis is an artificial device for replacing the damaged knee joint, which is made of metal, high molecular polyethylene, ceramic and other materials, according to the shape, structure and function of human knee joint, and is implanted into the human body by surgical technology to replace the diseased joint.

[0003] In reality, the prosthesis in the knee joint is generally made of metal. The metal prosthesis will produce small wear particles (such as metal debris, ions) during long-term friction and weight bearing. After these particles are phagocytosed by macrophages in the surrounding tissues, they will trigger local immune response and release inflammatory factors (such as TNF-α, IL-1), leading to synovial inflammation and soft tissue edema. When uncontrolled infection occurs around the artificial prosthesis (such as hip joint, knee joint prosthesis), the original infected prosthesis is removed by surgery, and an "spacer" containing antibiotics (instead of prosthesis to maintain joint space and stability) is implanted to temporarily "vacate" (vacate) the original prosthesis position, so as to control the infection and create conditions for subsequent reimplantation of the prosthesis. The core material of the spacer is antibiotic-containing bone cement.

[0004] However, the current bone cement spacer is generally shaped by hand according to the anatomical shape of the joint. Although the hand-shaped bone cement prosthesis can quickly adapt to the needs of the operation, it is difficult for medical personnel to accurately control the shape of the prosthesis with complex structures such as arc shape and irregular shape during the operation. The matching degree of the prosthesis with the patient's knee joint anatomical structure is often insufficient, which can easily cause poor joint stability, limited activity and other complications after the operation. According to clinical data statistics, the postoperative maladaptive rate of hand-shaped prosthesis is as high as 23%, which significantly increases the risk of secondary revision. Some are made using prefabricated molds. Although the prefabricated mold can improve the standardization of the shape of the prosthesis, it still faces difficulties in the demolding process of the arc-shaped prosthesis. Traditional molds are mostly of integral structure, which can easily form rigid friction with the bone cement during demolding, resulting in a probability of more than 15% of the prosthesis edge cracking and surface scratching, which seriously affects the mechanical properties and service life of the prosthesis. Secondly, it is more worth noting that the existing bone cement prosthesis lacks effective monitoring means during the solidification process, and medical personnel can only judge the solidification degree by experience, which often leads to prosthesis deformation due to premature demolding, or prolongs the operation time due to excessive waiting. In addition, the traditional bone cement material is blurred in the CT image, and the position deviation and loosening of the prosthesis after the operation cannot be accurately evaluated, which brings great inconvenience to the rehabilitation evaluation.

[0005] Based on the above clinical pain points, we have developed a manufacturing process of knee joint revision prosthesis with the functions of precise shaping, convenient demolding, real-time monitoring and clear imaging. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a manufacturing process for knee revision prostheses, solving the problems of insufficient precision in the plasticity of bone cement prostheses and difficulties in demolding, which lead to the inability to monitor prosthesis wear and curing status and blurred images in CT imaging.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A manufacturing process for a knee joint revision prosthesis includes a demolding frame, a first mold provided on the inner wall of one side of the demolding frame, a second mold provided on the upper left of the first mold, a third mold provided on the lower left of the first mold, and a prosthesis provided in the gap between the second mold, the third mold and the first mold; A filling block is inserted into the top of the second mold, and a temperature sensor is fixedly installed on the top of the filling block; A demolding assembly, which is mounted on a demolding frame and is used to release the prosthesis from the second mold, the third mold, and the first mold; An adjustment assembly, which is mounted on the demolding frame and is used to adjust the position of the temperature sensor; A limiting component is mounted on the demolding frame and is used to limit the first mold.

[0008] Preferably, the demolding assembly includes: Two first electric push rods are rotatably mounted at the upper and lower ends of the left side of the demolding frame, respectively. The other ends of the two first electric push rods are rotatably connected to the outer arc sidewalls of the second mold and the third mold, respectively. A second electric push rod is fixedly mounted on the right side of the demolding frame. The output end of the second electric push rod passes through the demolding frame. A folding top plate is fixedly mounted on the output end of the second electric push rod. The folding top plate is horizontally aligned with the groove in the middle of the right side of the first mold.

[0009] Preferably, the adjustment component includes: An adjusting rod is slidably mounted on the top of the demolding frame. A threaded sleeve is threaded onto the outer wall of the adjusting rod, and a connecting rod is rotatably mounted on the outer wall of the threaded sleeve. The other end of the connecting rod is fixedly connected to a temperature sensor.

[0010] Preferably, the limiting component includes: Four limiting posts are fixedly installed on the four corners of the right side of the first mold. All four limiting posts pass through the demolding frame. Limiting plates are engaged between the horizontally opposite limiting posts. Guide rods are slidably installed through and on the adjacent side of two of the limiting plates. The opposite ends of the two guide rods are fixedly connected to the demolding frame. Springs are sleeved on the outer walls of the two guide rods.

[0011] Preferably, the front and back sides of the second mold and the third mold are inserted with a plurality of pre-embedded rods, and the front and back sides of the prosthesis are provided with a plurality of filler holes, one end of the plurality of filler holes being inserted into the plurality of filler holes, respectively.

[0012] Preferably, the second mold is provided with an observation hole at the top, the filler block is matched with the observation hole, the filler block is provided with an injection hole at the top, and the detection end of the temperature sensor penetrates the injection hole.

[0013] A manufacturing process of a knee joint revision prosthesis, the processing technology of the prosthesis comprises the following steps: S1: manufacturing of demolding frame and mold: cutting stainless steel into a plurality of plates by laser cutting to ensure that the machining tolerance is ≤ ± 1mm, then welding the plurality of plates together by welding, and polishing smooth by a polisher, thereby forming a demolding frame, scanning the prosthesis to be replaced by non-contact 3D scanning, and obtaining a three-dimensional data model, then converting the digital model into a mold entity by 3D printing technology, and the raw material is polyetherimide with medical grade biocompatibility.

[0014] S2: surface treatment of mold entity: removing the support structure by tweezers and spatula to avoid damaging the body, polishing by sandpaper, manually polishing by sandpaper (80-200 mesh), file, or removing residual debris by ultrasonic cleaner (for small gaps), polishing by fine sandpaper (600-2000 mesh) and wool wheel with polishing paste until mirror effect Ra≤0.8μm, and uniformly spraying Teflon on the surface of the mold.

[0015] S3: disinfection and assembly of the mold, first rinsing the mold surface with flowing water or neutral detergent to remove visible stains, organic matter or inorganic matter, for places with gaps and grooves, soft hair brush or ultrasonic cleaning can be used, thoroughly removing residual dirt by cleaning at 30-60℃ for 10-20 minutes, connecting the demolding assembly on the demolding by splicing multiple molds together, and then inserting the pre-embedded rod into the through hole on the mold.

[0016] S4: pouring of the prosthesis: using polymethyl methacrylate bone cement with a powder-liquid mass ratio of 3:1, stirring and defoaming the bone cement by a vacuum stirrer, controlling the temperature at 20-25℃, and then injecting the bone cement into the mold by injection when the bone cement becomes paste, and removing bubbles by placing the demolding frame on a high-frequency vibration electric table for vibration during the injection process.

[0017] S5: installation of temperature sensor: adjusting the position of the adjustment assembly, and then inserting the detection end of the infrared temperature sensor into the injection hole of the filler block for detecting the temperature change of the prosthesis.

[0018] S6: Filling of imaging material: During the curing process, the degree of curing of bone cement can be observed by removing the filler block. After the bone cement has cured, the pre-embedded rod is pulled out to form a pre-embedded hole. Then, the paste-like bone cement and zirconia ceramic powder are mixed in a 1:1 ratio, and the mixed filler is injected into the filling hole.

[0019] S7: Demolding and Surface Treatment of the Prosthesis: After the filler and bone cement have fully cured, the molds are removed one by one by controlling the demolding components. Then, the prosthesis is placed in deionized water or a special cleaning solution and subjected to high-frequency ultrasonic vibration at 20-40kHz to remove tiny impurities and debris embedded in the surface. This method is especially suitable for cleaning complex structures. The prosthesis is then manually or mechanically polished with 80-400 grit sandpaper to form a uniform scratch texture.

[0020] Compared with the prior art, the present invention has the following beneficial effects: First, non-contact 3D scanning acquires three-dimensional data of the patient's knee joint, which is then combined with 3D printing technology to create a personalized mold. This ensures that the prosthesis shape closely matches the patient's anatomical structure, solving the problem of insufficient precision in manual shaping. The mold is made of medical-grade polyetherimide material, which has excellent biocompatibility and dimensional stability, and can be reused more than 50 times, reducing production costs.

[0021] 2. A split mold (first mold, second mold, and third mold) is used in conjunction with the demolding assembly. The second and third molds are separated from the sides of the prosthesis by the first electric push rod, and the first mold is deformed appropriately by the second electric push rod pushing the folded top plate to achieve non-contact demolding of the arc-shaped prosthesis.

[0022] Third, by precisely positioning the temperature sensor through the adjustment component, the temperature change during the bone cement curing process can be monitored in real time. Combined with the visual observation through the observation hole, the degree of curing can be scientifically judged. This monitoring method can shorten the waiting time for surgery and avoid prosthesis deformation caused by insufficient curing.

[0023] Fourth, a mixture of bone cement and zirconia ceramic powder is filled into the pre-designed filling holes of the prosthesis. Taking advantage of the high X-ray attenuation properties of zirconia, the prosthesis can be clearly visualized in CT images. Postoperatively, the displacement of the prosthesis position can be accurately assessed, providing a reliable basis for adjusting the rehabilitation plan. Attached Figure Description

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] Figure 1This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the regional structure of the demolding frame in this invention; Figure 4 This is a schematic diagram of the regional structure of the first mold in this invention; Figure 5 This is a schematic diagram of the combined structure of the third mold and the prosthesis in this invention; Figure 6 This is a schematic diagram of the second mold in this invention; Figure 7 This is a schematic diagram of the regional structure of the second mold in this invention; Figure 8 This is a schematic diagram of the regional structure of the limiting plate in this invention; Figure 9 This is a schematic diagram of the regional structure of the adjusting rod in this invention; Figure 10 This is a schematic diagram of the filling block in this invention.

[0026] Legend: 1. Demolding frame; 2. First electric push rod; 3. Adjusting rod; 4. First mold; 5. Second mold; 6. Embedded rod; 7. Third mold; 8. Folding top plate; 9. Second electric push rod; 10. Limiting post; 11. Limiting plate; 12. Temperature sensor; 13. Injection hole; 14. Connecting rod; 15. Prosthesis; 16. Filler hole; 17. Observation hole; 18. Filler block; 19. Guide rod; 20. Spring; 21. Threaded sleeve. Detailed Implementation

[0027] This application provides a manufacturing process for a knee revision prosthesis, which effectively solves the problems of insufficient plasticity of bone cement prostheses and inconvenient demolding, leading to unmonitored prosthesis wear and curing status, as well as blurred images in CT imaging. Example

[0028] like Figure 1 - Figure 10 As shown, the technical solution in this application embodiment effectively solves the technical problems of insufficient plasticity of bone cement prostheses and inconvenient demolding, which lead to prosthesis wear, inability to monitor the curing state, and blurred images in CT imaging. The overall idea is as follows: To address the problems existing in the prior art, the present invention provides a manufacturing process for a knee joint revision prosthesis, including a demolding frame 1, a first mold 4 disposed on the inner wall of one side of the demolding frame 1, a second mold 5 disposed on the upper left of the first mold 4, a third mold 7 disposed on the lower left of the first mold 4, and a prosthesis 15 disposed in the gap between the second mold 5, the third mold 7 and the first mold 4. A filling block 18 is inserted into the top of the second mold 5, and a temperature sensor 12 is fixedly installed on the top of the filling block 18. A demolding assembly is mounted on a demolding frame 1 and is used to release the prosthesis 15 from the second mold 5, the third mold 7, and the first mold 4. An adjustment assembly is mounted on the demolding frame 1 and is used to adjust the position of the temperature sensor 12; A limiting component is installed on the demolding frame 1 and is used to limit the first mold 4.

[0029] Furthermore, the demolding components include: Two first electric push rods 2 are rotatably installed at the upper and lower ends of the left side of the demolding frame 1, respectively. The other ends of the two first electric push rods 2 are rotatably connected to the outer arc sidewalls of the second mold 5 and the third mold 7, respectively. A second electric push rod 9 is fixedly installed on the right side of the demolding frame 1. The output end of the second electric push rod 9 passes through the demolding frame 1. A folding top plate 8 is fixedly installed on the output end of the second electric push rod 9. The folding top plate 8 is horizontally aligned with the groove in the middle of the right side of the first mold 4.

[0030] Furthermore, the adjustment components include: Adjusting rod 3 is slidably installed on the top of demolding frame 1. Threaded sleeve 21 is threaded on the outer wall of adjusting rod 3. Connecting rod 14 is rotatably installed on the outer wall of threaded sleeve 21. The other end of connecting rod 14 is fixedly connected to temperature sensor 12.

[0031] Furthermore, the limiting components include: Four limiting posts 10 are fixedly installed on the four corners of the right side of the first mold 4. All four limiting posts 10 penetrate the demolding frame 1. Limiting plates 11 are snapped between the horizontally opposite limiting posts 10. Guide rods 19 are slidably installed through and on the adjacent side of the two limiting plates 11. The opposite ends of the two guide rods 19 are fixedly connected to the demolding frame 1. Springs 20 are sleeved on the outer wall of the two guide rods 19.

[0032] Furthermore, multiple pre-embedded rods 6 are inserted into the outer walls of both the front and rear sides of the second mold 5 and the third mold 7.

[0033] Furthermore, the prosthesis 15 has multiple filling holes 16 on both the front and rear sides, and one end of each filling hole 16 is inserted into the filling hole 16.

[0034] Furthermore, the second mold 5 has an observation hole 17 on its top, and the filling block 18 is matched with the observation hole 17.

[0035] Furthermore, an injection hole 13 is provided on the top of the filling block 18, and the detection end of the temperature sensor 12 passes through the injection hole 13.

[0036] A manufacturing process for a knee revision prosthesis, the process of which includes the following steps: S1: Manufacturing of the demolding frame and mold: Stainless steel is cut into multiple plates using laser cutting (ensuring a processing tolerance of ≤±1mm). The plates are then welded together and polished smooth to form the demolding frame. The prosthesis to be replaced is scanned using non-contact 3D scanning to obtain a three-dimensional data model. The digital model is then converted into a mold entity using 3D printing technology. The raw material is polyetherimide, which has medical-grade biocompatibility.

[0037] S2: Surface treatment of the mold body: Remove the supporting structure with tweezers and scraper to avoid damaging the body. Sand it with sandpaper (80-200 grit) and file by hand, or use an ultrasonic cleaner (for tiny crevices) to remove residual debris. Use fine sandpaper (600-2000 grit) and a wool wheel with polishing compound until a mirror effect Ra≤0.8μm is achieved. Spray Teflon evenly on the mold surface.

[0038] S3: Disinfection and assembly of molds. First, rinse the mold surface with running water or neutral detergent to remove visible stains, organic or inorganic matter. For areas with gaps and grooves, use a soft brush or ultrasonic cleaning. Thoroughly remove residual dirt by cleaning at 30-60℃ for 10-20 minutes. Then, splice multiple molds together and connect them to the demolding components on the demolding device. Finally, insert the pre-embedded rod into the through hole on the mold.

[0039] S4: Casting of the prosthesis: Polymethyl methacrylate bone cement is used with a powder-to-liquid mass ratio of 3:1. The bone cement is stirred and degassed using a vacuum mixer, and the temperature is controlled at 20-25℃. When the bone cement becomes a paste, it is injected into the mold through the injection hole. During the injection process, the demolding frame is placed on a high-frequency vibrating electric table for vibration to remove air bubbles.

[0040] S5: Temperature sensor installation: By setting the position of the adjustment component, the detection end of the infrared temperature sensor is inserted into the injection hole of the filler block to detect temperature changes in the prosthesis.

[0041] S6: Filling of imaging material: During the curing process, the degree of curing of bone cement can be observed by removing the filler block. After the bone cement has cured, the pre-embedded rod is pulled out to form a pre-embedded hole. Then, the paste-like bone cement and zirconia ceramic powder are mixed in a 1:1 ratio, and the mixed filler is injected into the filling hole.

[0042] S7: Demolding and Surface Treatment of the Prosthesis: After the filler and bone cement have fully cured, the molds are removed one by one using the demolding components. The prosthesis is then placed in deionized water or a special cleaning solution, and high-frequency ultrasonic vibration at 20-40kHz is used to remove tiny impurities and embedded debris, especially suitable for cleaning complex structures. The prosthesis is then manually or mechanically polished with 80-400 grit sandpaper to create a uniform scratch texture. (Note:) Demolding frame 1: It is a U-shaped steel structure made of stainless steel, formed by welding multiple stainless steel components. It serves to fix the mold and assist in demolding. A sliding groove is provided on the top right side, and four sliding grooves are provided on the outer wall of the right side for installing the limiting post 10. First electric push rod 2: A DC electric push rod is adopted. One end is connected to the demolding frame 1 through a bearing seat and a metal shaft respectively. The other ends of the two first electric push rods 2 are connected to the U-shaped bearing seats on the second mold 5 and the third mold 7 respectively through a bearing seat and a metal shaft. Controlling the retraction of the first electric push rod 2 can detach the second mold 5 and the third mold 7 from the first mold 4. Adjusting rod 3: It consists of a metal threaded rod and a convex metal slider, which are fixed by welding. The convex metal slider is installed in the groove on the demolding frame 1. First mold 4: This is the mold inside the prosthesis 15. The coverage area needs to include the chamfered part on the right side of the prosthesis 15 so that the second mold 5, the third mold 7, and the first mold 4 can be separated from both sides of the prosthesis 15. This avoids the second mold 5 and the third mold 7 being unable to be demolded from the left side of the prosthesis 15. Polyetherimide is used. Triangular grooves are provided in the middle of the arc-shaped inner wall, the middle of the right outer wall, and the corner so that bending can be performed at the groove positions. The second mold 5 is made of polyetherimide and is the mold for the outer arc surface of the prosthesis 15. A U-shaped bearing is provided in the middle of one side of the outer arc surface. Embedded rod 6: It is a titanium alloy rod, which is embedded in the inner cavity of the second mold 5, the third mold 7 and the first mold 4 to facilitate the formation of filling hole 16 in the prosthesis 15; The third mold 7 is made of polyetherimide and is the mold for the outer arc surface of the prosthesis 15. A U-shaped bearing is provided in the middle of one side of the outer arc surface. The folding top plate 8 is a metal triangular prism, which is fixed to the output end of the second electric push rod 9 by bolts; Second electric push rod 9: A DC electric push rod is fixed to the demolding frame 1 by a metal bracket and bolts; Limiting post 10: It is cylindrical, made of polyetherimide, and is integrated with the first mold 4. The inner sides of the two horizontally opposite limiting posts 10 are provided with slots, which cooperate with the limiting plate 11 to restrict the first mold 4 from disengaging from the demolding frame 1. Limiting plate 11: It is an E-shaped metal plate with a through hole in the middle. It is installed on the guide rod 19 and is used to limit the limiting post 10. Temperature sensor 12: It is an infrared temperature sensor, which is fixed to one end of the connecting rod 14 by a metal bracket and bolts. It is installed vertically, and the size of the detection end is smaller than the size of the injection hole 13. Injection hole 13: is a cylindrical through hole that communicates with the internal cavities of the first mold 4, the second mold 5, and the third mold 7; Connecting rod 14: It is a stainless steel bracket with a ring welded to one end for rotating on the threaded sleeve 21; Prosthesis 15: Made of bone cement, it is a prosthesis for knee replacement. Filler hole 16: It is a cylindrical hole used to fill the imaging filler material, which facilitates CT scanning to see the overall outline of the prosthesis 15, thereby determining the state of the prosthesis 15. Observation hole 17: It is square-shaped and is used to remove the filling block 18 in the observation hole 17 to observe the curing state of the bone cement; Filler block 18: It is part of the second mold 5 but can be removed to facilitate observation of the prosthesis 15; Guide rod 19: It is a stainless steel metal rod, with a limit block fixed to one end by bolts to prevent the limit plate 11 from separating from the guide rod 19; Spring 20: It is a stainless steel spring, and its two ends are fixed to the limiting plate 11 and the demolding frame 1 by welding; Threaded sleeve 21: It is a stainless steel internal threaded sleeve with an annular groove on the outer wall for installing the connecting rod 14 and limiting the connecting rod 14 by a snap ring.

[0043] Working principle: The first step is to scan the prosthesis to be replaced using 3D scanning, and then 3D print the first mold 4, the second mold 5, the third mold 7, the limiting post 10, and the filling block 18. The limiting post 10 is then inserted through the groove on the right outer wall of the demolding frame 1, and the limiting plate 11 is used to lock the groove on the limiting post 10, thereby positioning the first mold 4. Then, the output ends of the two first electric push rods 2 are connected to the U-shaped shaft seats on the second mold 5 and the third mold 7 respectively through the metal shaft. Next, the filling block 18 is inserted into the observation hole 17. Finally, the pre-embedded rod 6 is inserted into the second mold 5 and the third mold 7, thereby completing the mold assembly.

[0044] The second step involves injecting bone cement into the inner cavities of the first mold 4, the second mold 5, and the third mold 7. During the process of bone cement curing to form the prosthesis 15, a pre-embedded rod 6 is set to create filling holes 16 on the cured bone cement. During the curing process, the temperature of the bone cement will rise in the later stages of curing. The temperature of the prosthesis 15 is detected by the temperature sensor 12 to determine whether the bone cement has cured. After the prosthesis 15 is fixed, the pre-embedded rod 6 is pulled out. Then, the imaging material is mixed with the bone cement and filled into the filling holes 16, and then cured again. This allows the overall outline of the prosthesis 15 to be observed under CT scan, thus understanding the state of the prosthesis 15.

[0045] Thirdly, by removing the filling block 18, the curing state of the bone cement can be observed through the observation hole 17. After complete curing, the first electric push rod 2 on the upper left can be controlled to retract, causing the second mold 5 to separate from the prosthesis 15. Then, the first electric push rod 2 on the lower left can be controlled to retract, causing the third mold 7 to separate from the prosthesis 15. At this point, the prosthesis 15 can be manually removed from the first mold 4, thus completing the demolding. If the first mold 4 and the prosthesis 15 are stuck together, the second electric push rod 9 can be controlled to extend, causing the folding top plate 8 to abut against the groove on the right side of the first mold 4. Due to the presence of the groove, this part of the first mold 4 is easy to complete. Then, under the pushing force of the folding top plate 8, the upper and lower sides of the first mold 4 are brought together towards the middle. During the closing process, the limiting post 10 will move closer to the direction of the second electric push rod 9. At the same time, the limiting post 10 and the limiting plate 11 move relative to each other. During the folding and closing of the first mold 4, the stuck prosthesis 15 can be detached, thus facilitating the demolding of the prosthesis 15.

[0046] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A knee revision prosthesis, characterized in that, Include: The demolding frame (1), one side inner wall is provided with first mold (4), the upper left of first mold (4) is provided with second mold (5), the lower left of first mold (4) is provided with third mold (7), the gap between second mold (5) and third mold (7) and first mold (4) is provided with prosthesis (15); Fill the block (18), the top of the filling block (18) is inserted into the top of the second mold (5), and the temperature sensor (12) is fixedly installed on the top of the filling block (18); Demolding assembly, the demolding assembly is installed on the demolding frame (1), and is used for separating the prosthesis (15) from the second mold (5) and the third mold (7) and the first mold (4); Adjusting assembly, the adjusting assembly is installed on the demolding frame (1), and is used for adjusting the position of the temperature sensor (12); Limiting assembly, the limiting assembly is installed on the demolding frame (1), and is used for limiting the first mold (4).

2. The knee revision prosthesis of claim 1, wherein, The demolding assembly comprises: Two first electric push rods (2), two first electric push rods (2) are rotatably installed at the upper and lower ends of the left side of the demolding frame (1), respectively, and the other end of the two first electric push rods (2) is rotatably connected with the outer arc side wall of the second mold (5) and the third mold (7), respectively, the second electric push rod (9) is fixedly installed on the right side of the demolding frame (1), the output end of the second electric push rod (9) penetrates the demolding frame (1), the output end of the second electric push rod (9) is fixedly installed with the folding top plate (8), and the folding top plate (8) is horizontally aligned with the groove in the middle of the right side of the first mold (4).

3. The knee revision prosthesis of claim 1, wherein, The adjusting assembly comprises: Adjusting rod (3), the adjusting rod (3) is slidably installed on the top of the demolding frame (1), the adjusting rod (3) is threadedly connected with the threaded sleeve (21) on the outer wall, the threaded sleeve (21) is rotatably connected with the connecting rod (14) on the outer wall, and the other end of the connecting rod (14) is fixedly connected with the temperature sensor (12).

4. The knee revision prosthesis of claim 1, wherein, The limiting assembly comprises: Four limiting columns (10), four limiting columns (10) are fixedly installed on the four corners of the right side of the first mold (4), respectively, four limiting columns (10) penetrate the demolding frame (1), the limiting columns (10) are horizontally arranged, and the limiting plates (11) are clamped between the limiting columns (10), the adjacent sides of the two limiting plates (11) penetrate and are slidably installed with guide rods (19), the opposite ends of the two guide rods (19) are fixedly connected with the demolding frame (1), and the outer walls of the two guide rods (19) are sleeved with springs (20).

5. The knee revision prosthesis of claim 1, wherein: The front and back outer walls of the second mold (5) and the third mold (7) are inserted with a plurality of embedded rods (6).

6. The knee revision prosthesis of claim 1, wherein: The front and back sides of the prosthesis (15) are provided with a plurality of filler holes (16), and one end of the plurality of filler holes (16) is inserted into the plurality of filler holes (16).

7. The knee revision prosthesis of claim 1, wherein: The top of the second mold (5) is provided with an observation hole (17), and the filling block (18) is matched with the observation hole (17).

8. The knee revision prosthesis of claim 1, wherein: The filling block (18) is provided with an injection hole (13) at the top, and the detection end of the temperature sensor (12) penetrates the injection hole (13).

9. A process for manufacturing a revision knee prosthesis, characterized in that, The processing procedure of the prosthesis comprises the following steps: S1: manufacturing of the demolding frame and the mold: cutting stainless steel into multiple plates by laser cutting to ensure that the machining tolerance is ≤±1mm, then welding the multiple plates together by welding, and polishing them smooth by a sander, thereby forming the demolding frame, scanning the prosthesis to be replaced by non-contact 3D scanning, and obtaining a three-dimensional data model, then converting the digital model into a mold entity by 3D printing technology, and the raw material is polyetherimide, which has medical-grade biocompatibility; S2: surface treatment of the mold entity: removing the support structure by tweezers and spatula to avoid damaging the body, polishing by sandpaper, manually polishing with sandpaper (80-200 mesh), a file, or removing residual debris with an ultrasonic cleaning machine (for small gaps), polishing with fine sandpaper (600-2000 mesh) and a wool wheel with polishing paste until a mirror finish is achieved with Ra≤0.8μm, and evenly spraying Teflon on the surface of the mold; S3: disinfection and assembly of the mold, first rinsing the surface of the mold with flowing water or neutral detergent to remove visible stains, organic matter or inorganic matter, for places with gaps and grooves, a soft brush or ultrasonic cleaning can be used, thoroughly removing residual dirt by cleaning at 30-60℃ for 10-20 minutes, connecting the demolding assembly on the demolding frame by splicing multiple molds together, and then inserting the pre-embedded rod into the through hole on the mold; S4: pouring of the prosthesis: using polymethyl methacrylate bone cement with a powder-liquid mass ratio of 3:1, stirring and degassing the bone cement with a vacuum stirrer, controlling the temperature at 20-25℃, and then pouring the bone cement into the mold through injection when the bone cement becomes paste-like, and removing bubbles by placing the demolding frame on a high-frequency vibration electric table and vibrating during the injection process; S5: installation of the temperature sensor: adjusting the position of the adjustment assembly, then inserting the detection end of the infrared temperature sensor into the injection hole of the filling block to detect the temperature change of the prosthesis; S6: filling of the radiographic material: during the curing process, the curing degree of the bone cement can be observed by removing the filling block, after the bone cement is cured, the pre-embedded rod is pulled out to form a pre-embedded hole, then the paste-like bone cement and zirconia ceramic powder are mixed in a 1:1 ratio, and the mixed filling material is injected into the filling hole; S7: demolding and surface treatment of the prosthesis: after the filling material and the bone cement are completely cured, the mold is separated one by one by controlling the demolding assembly, then the prosthesis is placed in deionized water or special cleaning solution, and the high-frequency ultrasonic vibration at 20-40kHz is used to strip off small impurities and embedded debris, especially suitable for cleaning complex structures, and 80-400 grit sandpaper is used for manual or mechanical grinding to form uniform scratch texture.

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