A child tibial tumor type rotational hinge knee prosthesis

Abstract

The application discloses a child tibia tumor type rotary hinge knee joint prosthesis and belongs to the medical instrument field, which comprises: a femur end prosthesis, a tibia pad and a bionic joint connecting piece. The femur end prosthesis comprises a positioning plate body, the positioning plate body is provided with a connecting part and a butt joint rod, the tibia pad is detachably connected with the positioning plate body and is provided with a concave arc joint surface, the bionic joint connecting piece is provided with a butt joint hole and a rotating pin, the butt joint hole is movably connected with the butt joint rod through a ligament bionic mechanism, the bionic joint connecting piece is allowed to rotate around the butt joint rod and is allowed to reciprocate along the axis of the butt joint rod within a set distance range, and the ligament bionic mechanism generates an elastic restoring force when the bionic joint connecting piece and the butt joint rod relatively displace, the tibia end prosthesis is provided with a connecting hole and is rotatably connected with the rotating pin through the connecting hole, and the tibia end prosthesis is further provided with a convex arc joint surface. Through the above arrangement, the tibia end prosthesis is allowed to rotate around the butt joint rod and the rotating pin respectively, so that the internal and external rotation actions and the flexion action of the lower leg are realized.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a rotating hinge knee joint prosthesis for pediatric tibial tumors. Background Technology

[0002] In recent years, with the continuous advancement of medical technology, the treatment methods for bone tumors have become increasingly diverse. In the field of bone tumor treatment, especially for malignant tumors around the knee joint in children and adolescents, this has always been a focus of medical attention. Because children and adolescents are in a stage of growth and development, the resection of malignant tumors around the knee joint must not only consider the radical removal of the tumor but also the normal growth and functional recovery of the child's limbs.

[0003] In existing technologies, knee prostheses typically consist of two parts: a tibial prosthesis and a femoral prosthesis, connected by a hinge joint. Currently, common knee prostheses are primarily suitable for adults whose epiphyses have closed and will not continue to develop. When part of the femur is removed and replaced with a femoral prosthesis, the replaced bone area includes the patient's closed femoral epiphysis. If such prostheses are directly applied to pediatric patients, their epiphysis also needs to be removed to achieve a proper fit between the femur and the prosthesis. Unlike adults, children's epiphysis continues to develop; therefore, removing the epiphysis will affect the final developmental length of the leg bone on that side, severely impacting the patient's daily life and mental health.

[0004] To address these issues, existing technologies also include joint hinge prostheses suitable for children's knees. The portion connecting to the femur requires only the removal of a small portion of the epiphysis. By incorporating a rod inserted into the femur to improve structural stability, the amount of epiphyseal resection can be significantly reduced. However, this improved product still has technical drawbacks: after knee replacement, children can perform knee flexion and extension movements, but the hinge does not support internal or external rotation of the lower leg, failing to restore circumferential rotation of the leg. This causes stress concentration in the child's leg during movement, easily leading to prosthesis breakage or loosening.

[0005] Therefore, a joint prosthesis was designed, which is a rotating hinge knee joint prosthesis for pediatric tibial tumors. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this application provides a pediatric tibial tumor type rotating hinge knee joint prosthesis to simulate the movement of a child's knee joint, allowing the lower leg to perform internal and external rotation and flexion movements at a certain angle, and generating elastic restoring force to return to the initial position, thereby improving the fit and comfort of knee joint prostheses for pediatric tibial tumor patients.

[0007] This application is achieved through the following technical solution:

[0008] A pediatric tibial tumor-type rotating hinge knee prosthesis includes:

[0009] A femoral end prosthesis has a positioning plate for the epiphysis of the femoral end set between its upper and lower ends. The upper end of the positioning plate has a connecting part for docking and fixing with the femur, and the lower end has a vertically arranged docking rod; the upper end is defined as the end facing the femur, and the lower end is defined as the end facing the tibia.

[0010] The tibial pad is detachably connected to the lower end of the positioning plate, and the lower end of the tibial pad is provided with a concave arc-shaped articular surface;

[0011] The bionic joint connector has a vertically arranged docking hole at the upper end and a horizontally arranged rotating pin at the lower end. The docking hole is movably connected to the docking rod through a ligament bionic mechanism. The ligament bionic mechanism allows the bionic joint connector to rotate around the docking rod and allows the bionic joint connector to reciprocate within a set distance range along the axis of the docking rod. Furthermore, the ligament bionic mechanism can generate an elastic restoring force when there is relative displacement between the bionic joint connector and the docking rod, so as to drive the bionic joint connector and the docking rod to return to their initial position.

[0012] The tibial prosthesis has a transversely arranged connecting hole in the middle, and the tibial prosthesis is rotatably connected to the rotating pin through the connecting hole; the upper end of the tibial prosthesis is provided with a convex arcuate articular surface adapted to the concave arcuate articular surface; wherein, the convex arcuate articular surface and the concave arcuate articular surface cooperate to form a rotational curved surface pair, allowing the tibial prosthesis to rotate around the connecting rod, thereby realizing the internal and external rotation of the lower leg.

[0013] This design allows the positioning plate of the pediatric tibial tumor-type rotating hinge knee prosthesis to be docked and fixed to the femur, requiring only a small portion of the epiphysis to be removed, thus minimizing the impact on children's bone development. The biaxial rotational structure and ligament bionic mechanism of the bionic joint connector enable the tibial prosthesis to rotate horizontally while still allowing knee flexion. Through the cooperation of convex and concave arcuate articular surfaces, it achieves internal and external rotation of the lower leg, better mimicking the movement of the human knee joint. This allows children to maintain a high degree of mobility during bone growth and provides stable support and flexible movement as the bones develop. This design reduces stress concentration on the prosthesis during movement, lowers the risk of falls, and reduces wear and tear between the prosthesis and bone.

[0014] Furthermore, the tibial pad has a limiting groove on the side away from the patellar groove to restrict the rotation angle of the bionic joint connector, and the bionic joint connector has abutment portions on both sides that are adapted to the limiting groove; the abutment portions and the limiting groove form a deflection gap; the end of the tibial prosthesis has a movable groove on the side away from the patellar groove that is adapted to the bionic joint connector. This allows the limiting groove and the abutment portions to restrict the rotation angle of the bionic joint connector, ensuring that it rotates within a set angle range, improving safety and stability; the deflection gap allows the bionic joint connector to rotate flexibly within a certain range, increasing its range of motion; the movable groove provides space for the bionic joint connector to move, further enhancing the overall flexibility of the pediatric tibial tumor-type rotating hinge knee joint prosthesis.

[0015] Furthermore, the ligament bionic mechanism includes a sleeve fixed in the docking hole. The sleeve is made of a flexible material, and a blind hole is provided in the middle of the sleeve for connection with the docking rod; the docking rod is fixed in the blind hole. The sleeve is externally connected and fixed to the bionic joint connector, and internally connected and fixed to the docking rod. The sleeve is made of a flexible material, which on the one hand can act as a buffer connection between the docking rod and the bionic joint connector, reducing hard collisions between components during movement, reducing wear, extending the service life of the prosthesis, and reducing discomfort for children during activity; on the other hand, the flexibility allows the sleeve and the bionic joint connector to move relative to each other, including axial and horizontal rotation, so as to achieve horizontal rotation of the bionic joint connector, allowing the joint prosthesis to better simulate the movement of the human knee joint, and allowing children to experience bone-related changes. It maintains a high degree of mobility during the growth stage and continues to provide stable support and flexible movement as the bones develop, effectively avoiding the limb function limitations caused by insufficient mobility of traditional prostheses. This allows children to perform daily activities more naturally during rehabilitation. The flexible sleeve also allows for more flexible movement between the bionic joint connector and the connecting rod, generating elastic restoring force to drive both back to their initial positions. It also ensures that the convex arcuate articular surface on the tibial end prosthesis always abuts against the concave arcuate articular surface on the tibial pad, providing effective support and reducing the occurrence of collisions during knee joint movement due to gaps.

[0016] Furthermore, the ligament bionic mechanism includes a sleeve fixed in the docking hole, the sleeve having a blind hole in the middle for connecting with the docking rod; the docking rod is movably connected in the blind hole, and a pressure chamber is formed between the docking rod and the blind hole; the positioning plate has a ventilation channel arranged along the length of the docking rod, the ventilation channel is connected to the pressure chamber, and the positioning plate has a plug for sealing the ventilation channel.

[0017] By adopting the above technical solution, the venting channel can easily expel air between the blind hole and the connecting rod during the assembly of the connecting rod and the blind hole, facilitating a smooth assembly process. After the connecting rod and the blind hole are assembled, the venting channel is sealed with a plug. When the bionic joint connector and the connecting rod are relatively displaced, the air pressure change in the air chamber generates an elastic restoring force, allowing the bionic joint connector and the connecting rod to return to their initial position. This ensures that the convex arcuate articular surface on the tibial prosthesis always abuts against the concave arcuate articular surface on the tibial pad, providing effective support and reducing collisions during knee joint movement due to gaps. This connection method allows for relative movement between the connecting rod and the blind hole, including axial and horizontal rotation, enabling horizontal rotation of the bionic joint connector. This allows the joint prosthesis to more accurately simulate the movement of the human knee joint. This design significantly enhances the realism and naturalness of movement. For pediatric patients, it offers greater mobility during bone growth compared to traditional prostheses, providing continuous stable support and flexible movement as the bones develop. This effectively avoids limb function limitations caused by insufficient mobility in traditional prostheses, allowing pediatric patients to perform daily activities more naturally and comfortably during rehabilitation, reducing discomfort and psychological burden. Furthermore, this structural design facilitates easy adjustment and replacement of components. The sleeve can be made of rigid material, allowing for adjustments to the relative installation position between the femoral and tibial prostheses or replacement of prosthesis components during the child's growth and development. This makes operations more convenient, reduces maintenance costs and risks, and improves the prosthesis's lifespan and applicability.

[0018] Furthermore, a sealing element is provided between the docking rod and the blind hole to ensure the airtightness of the air pressure chamber. By providing a sealing element between the docking rod and the blind hole, the airtightness of the air pressure chamber can be guaranteed, thereby making the movement of the knee joint prosthesis more stable and also helping to maintain the normal function of the knee joint prosthesis.

[0019] Furthermore, the lower end of the bionic joint connector is provided with a pin hole, which communicates with the docking hole; the docking hole penetrates the bionic joint connector and has a fixing hole at the bottom of the bionic joint connector; the rotating pin is detachably connected in the pin hole, and the middle of the rotating pin is provided with a positioning hole that matches the sleeve; the sleeve penetrates the pin hole and the positioning hole and is inserted into the fixing hole; the blind hole extends into the positioning hole, and the docking rod extends into the positioning hole. The knee joint prosthesis is connected to the docking rod through a blind hole in the sleeve. The rotating pin is detachably connected to the pin hole and has a positioning hole that matches the sleeve. This achieves a stable connection between the bionic joint connector, the docking rod, and the rotating pin, ensuring the reliability of the connection between the components. This helps maintain the overall structural stability of the knee joint prosthesis, providing reliable joint support for pediatric patients. It also facilitates the installation and removal of components, making the assembly and maintenance of the prosthesis easier. The sleeve passes through the pin hole and is inserted into the fixing hole. The blind hole extends into the positioning hole, and the docking rod extends to the positioning hole. This makes the connection between the femoral end prosthesis, the bionic joint connector, and the tibial end prosthesis more stable, enhancing the overall reliability and stability of the prosthesis. At the same time, it ensures the smooth rotation of the bionic joint connector around the docking rod, helping pediatric patients achieve a higher range of motion.

[0020] Furthermore, the lower edge of the positioning plate is provided with a locking groove, and the edge of the tibial pad is provided with a locking flange that matches the locking groove. The side of the positioning plate near the patellar groove is provided with a first fastening hole for fixing the tibial pad, and the tibial pad is provided with a second fastening hole that matches the first fastening hole. The locking groove at the lower end of the positioning plate engages with the locking flange at the edge of the tibial pad, and the first fastening hole on the positioning plate and the second fastening hole on the tibial pad engage to achieve a stable connection between the femoral prosthesis and the tibial pad, improving the overall stability and reliability of the prosthesis. The installation method is simple, helps to reduce the wound area, and reduces postoperative infection.

[0021] Furthermore, the tibial prosthesis has a suture hole for fixing the patellar ligament at the end near the patellar groove; the suture hole has an arc-shaped channel path. The rotating hinge knee prosthesis can fix the patellar ligament through the suture hole, preserving the normal ligament to maintain joint function, and the arc-shaped suture hole path can better adapt to the structure and movement of the patellar ligament.

[0022] Furthermore, a bushing is provided between the connecting hole and the rotating pin, and the bushing has a positioning shoulder that limits the relative position between the bionic joint connector and the tibial prosthesis. By providing a bushing between the connecting hole and the rotating pin, and by providing a positioning shoulder on the bushing, the relative position between the bionic joint connector and the tibial prosthesis can be limited. This allows for more precise coordination of the components of the pediatric tibial tumor-type rotating hinge knee joint prosthesis, ensuring the stability and reliability of the prosthesis and facilitating better joint mobility for pediatric patients using the prosthesis.

[0023] Furthermore, the connecting part includes a medullary canal extension body disposed at the upper end of the positioning plate, and the upper end of the positioning plate is provided with an anti-rotation protrusion capable of engaging with the femur; the lower end of the tibial prosthesis is provided with a vertebral groove for docking and fixation with the tibia. The medullary canal extension body at the upper end of the positioning plate can achieve docking and fixation with the femur, the anti-rotation protrusion at the upper end of the positioning plate engages with the femur to ensure fixation strength, and the vertebral groove at the lower end of the tibial prosthesis can achieve docking and fixation with the tibia, so that the pediatric tibial tumor type rotating hinge knee joint prosthesis can be better connected and fixed with the femur and tibia.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention comprises an interconnected femoral prosthesis, a bionic joint connector, and a tibial prosthesis, constructing a dual-axis system of "femoral prosthesis-bionic joint connector-tibial prosthesis." Specifically, the dual axes are the flexion-extension axis around the rotating pin and the rotation axis around the connecting rod. The rotational surface pair formed by the convex arcuate articular surface of the tibial prosthesis and the concave arcuate articular surface of the tibial pad successfully simulates the flexion-extension movements of the human knee joint, as well as internal and external rotation functions within a certain rotational angle.

[0026] 2. This invention features a flexible sleeve and pneumatic chamber structure, effectively mimicking ligament structures. It generates elastic restoring force when the prosthesis components undergo relative movement and rotation, consistently driving the joint surfaces to return to their original alignment. Simultaneously, it avoids the risks of direct stress transmission and lack of cushioning associated with traditional rigid hinges during activity, further preventing stress concentration at the hinge during children's movements and the inability of the hinge joint to automatically return to its original position after activity. It absorbs impact energy during walking, running, and jumping, protecting the connection interface between the bone and the prosthesis, reducing the risk of loosening, and providing children with ligament-like mechanical feedback, helping them perceive joint position and improving motor control. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0028] Figure 1 This is a three-dimensional view of the overall structure of one embodiment of the present invention;

[0029] Figure 2 This is a front view of the overall structure of one embodiment of the present invention;

[0030] Figure 3 yes Figure 2A schematic diagram of the cross-sectional structure along direction A.

[0031] Figure 4 This is a right view of the overall structure of one embodiment of the present invention;

[0032] Figure 5 yes Figure 4 A schematic diagram of the cross-sectional structure along the B direction;

[0033] Figure 6 yes Figure 5 A magnified view of the structure at point C in the middle;

[0034] Figure 7 This is a three-dimensional structural diagram of a femoral end prosthesis according to an embodiment of the present invention;

[0035] Figure 8 This is a three-dimensional structural diagram of a tibial pad in one embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the assembly structure of a biomimetic joint connector and sleeve in one embodiment of the present invention;

[0037] Figure 10 This is a three-dimensional structural schematic diagram of a biomimetic joint connector according to an embodiment of the present invention;

[0038] Figure 11 This is a three-dimensional structural diagram of a sleeve in one embodiment of the present invention;

[0039] Figure 12 This is a three-dimensional structural diagram of one embodiment of the tibial prosthesis of the present invention;

[0040] Figure 13 This is a schematic diagram of another three-dimensional structure of the tibial prosthesis in one embodiment of the present invention;

[0041] Figure 14 This is a schematic diagram of a partial assembly structure in Embodiment 2 of the present invention;

[0042] Figure 15 This is a schematic diagram of the assembly structure of the bionic joint connector in Embodiment 2 of the present invention.

[0043] In the diagram, 1. Femoral end prosthesis; 11. Positioning plate; 111. Snap-fit ​​groove; 12. Connecting part; 13. Docking rod; 131. Ventilation channel; 132. Plug; 14. Anti-rotation boss; 15. First fastening hole; 2. Tibial pad; 21. Concave arc-shaped articular surface; 22. Second fastening hole; 23. Limiting groove; 24. Snap-fit ​​flange; 3. Bionic joint connector; 31. Docking hole; 32. Pin hole; 33. Fixing hole; 34. Sleeve; 341. Blind hole; 342. Air pressure chamber; 35. Abutment part; 36. Rotating pin; 361. Positioning hole; 37. Bushing; 371. Positioning shoulder lift; 4. Tibial end prosthesis; 41. Protruding arc-shaped articular surface; 42. Movable groove; 43. Connecting hole; 44. Suture hole; 45. Vertebral fitting groove. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention are clearly and completely described below through specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1:

[0046] Reference Figures 1 to 6 This application discloses a pediatric tibial tumor-type rotating hinge knee joint prosthesis, comprising:

[0047] The femoral prosthesis 1 has a positioning plate 11 simulating the epiphysis of the femoral end between its upper and lower ends. The thickness of the positioning plate 11 is less than that of the epiphysis of the actual femoral end. The upper end of the positioning plate 11 has a connecting part 12 for docking and fixing with the femur, and the lower end has a vertically arranged docking rod 13. The upper end is defined as the end facing the femur, and the lower end is defined as the end facing the tibia. The tibial pad 2 is detachably connected to the lower end of the positioning plate 11, and the lower end of the tibial pad 2 has a concave arc-shaped articular surface 21. The bionic joint connector 3 has a vertically arranged docking hole 31 at its upper end and a horizontally arranged rotating pin 36 at its lower end. The docking hole 31 is movably connected to the docking rod through a ligament bionic mechanism. On the 13th, the ligament bionic mechanism allows the bionic joint connector 3 to rotate around the docking rod 13 and allows the bionic joint connector 3 to reciprocate within a set distance range along the axis of the docking rod 13. Furthermore, the ligament bionic mechanism can generate an elastic restoring force when relative displacement occurs between the bionic joint connector 3 and the docking rod 13, driving the bionic joint connector 3 and the docking rod 13 back to their initial positions. The tibial prosthesis 4 has a transversely arranged connecting hole 43 in the middle, and the tibial prosthesis 4 is rotatably connected to the rotating pin 36 through the connecting hole 43. The upper end of the tibial prosthesis 4 is provided with a convex arcuate joint surface 41 adapted to the concave arcuate joint surface 21. The convex arcuate joint surface and the concave arcuate joint surface cooperate to form a rotational curved surface pair, allowing the tibial prosthesis to rotate around the docking rod, thereby realizing the internal and external rotation of the lower leg.

[0048] For details, please refer to Figures 1 to 6 The femoral prosthesis 1 has a positioning plate 11 in the middle that mimics the femoral epiphysis. The upper end of the positioning plate 11 has a connecting part 12 for docking and fixing with the femur. The connecting part 12 includes a medullary canal elongator located at the upper end of the positioning plate 11. The medullary canal elongator can penetrate deep into the femoral medullary canal, providing a stable connection. Its shape is typically cylindrical, and the material can be high-strength metals such as titanium alloy, or cobalt-chromium-molybdenum alloy, which have good biocompatibility and strength. The upper end of the positioning plate 11 also has an anti-rotation boss 1 that can fit into the femur. 4. The anti-rotation boss 14 is generally irregular in shape, such as rectangular or trapezoidal. It can be embedded in the corresponding groove of the femur to prevent the prosthesis from rotating on the femur, thus ensuring the strength and stability of the fixation. The lower end of the positioning plate 11 is provided with a vertically arranged docking rod 13. The docking rod 13 is usually cylindrical with a smooth surface to facilitate connection with other components. The docking rod 13 can be solid or hollow. A hollow docking rod 13 can reduce the weight of the prosthesis and also reduce the use of materials. It also facilitates the exhaust of air from the assembly space, which is beneficial for installation.

[0049] refer to Figures 4 to 8The lower edge of the positioning plate 11 is provided with a snap-fit ​​groove 111, which can be an annular groove or multiple evenly distributed rectangular grooves. The edge of the tibial pad 2 is provided with a snap-fit ​​flange 24 that matches the snap-fit ​​groove 111. The snap-fit ​​flange 24 can be an annular protrusion or a rectangular protrusion corresponding to the snap-fit ​​groove 111. During installation, the snap-fit ​​flange 24 is snapped into the snap-fit ​​groove 111 to achieve the initial connection between the tibial pad 2 and the positioning plate 11. The side of the positioning plate 11 near the patellar groove is provided with a first fastening hole 15 for fixing the tibial pad 2. The first fastening hole 15 is generally a threaded hole. The tibial pad 2 is provided with a second fastening hole 22 that matches the first fastening hole 15. By screwing screws into the first fastening hole 15 and the second fastening hole 22, the connection between the tibial pad 2 and the positioning plate 11 can be further strengthened, making the connection more secure.

[0050] refer to Figures 2 to 8 The tibial pad 2 is detachably connected to the lower end of the positioning plate 11, and the lower end of the tibial pad 2 is provided with a concave arc-shaped articular surface 21. The shape of the concave arc-shaped articular surface 21 matches the physiological structure of the human knee joint and can better adapt to the movement of the joint. The side of the tibial pad 2 away from the patellar groove is provided with a limiting groove 23 to limit the rotation angle of the bionic joint connector 3. The limiting groove 23 can be an arc-shaped groove or a rectangular groove, etc. Its function is to prevent the bionic joint connector 3 from rotating excessively and to protect the safety of the joint.

[0051] refer to Figures 6 to 9 The bionic joint connector 3 has abutment portions 35 on both sides that are adapted to the limiting groove 23. The abutment portions 35 can be block-shaped or column-shaped. When the bionic joint connector 3 rotates to a certain angle, the abutment portions 35 will abut against the limiting groove 23, thereby limiting its rotation angle. The abutment portions 35 and the limiting groove 23 have a deflection gap. The existence of the deflection gap allows the bionic joint connector 3 to rotate freely within a certain range, ensuring the flexibility of the joint.

[0052] refer to Figure 6 as well as Figures 9 to 11The bionic joint connector 3 has a vertically arranged docking hole 31 at its upper end, which penetrates the bionic joint connector 3. A fixing hole 33 is also present at the bottom of the bionic joint connector 3. The docking hole 31 is used to accommodate the ligament bionic mechanism and the docking rod 13. The lower end of the bionic joint connector 3 has a pin hole 32, which communicates with the docking hole 31. The pin hole 32 is used to install a rotating pin 36. The rotating pin 36 is detachably connected to the pin hole 32, and a positioning hole 361 adapted to the sleeve 34 is provided in the middle of the rotating pin 36. The rotating pin 36 is generally cylindrical with a smooth surface to facilitate rotation. The ligament bionic mechanism includes a sleeve 34 fixed in the docking hole 31, which can be fixed by bonding. The sleeve 34 is made of a flexible material, such as polyethylene, which has good elasticity and wear resistance. The middle part of the sleeve 34 is provided with a blind hole 341 for connecting with the docking rod 13. The docking rod 13 can be fixed in the blind hole 341 by bonding. The sleeve 34 passes through the pin hole 32 and the positioning hole 361 and is inserted into the fixing hole 33. The docking rod 13 extends into the positioning hole 361 to limit the rotation pin 36 and prevent it from moving left and right.

[0053] refer to Figures 12 to 13 The tibial prosthesis 4 has a convex arcuate articular surface 41 at its upper end that matches the concave arcuate articular surface 21. The convex arcuate articular surface 41 and the concave arcuate articular surface 21 cooperate with each other to realize the rotation and sliding of the joint. The tibial prosthesis 4 has a transversely arranged connecting hole 43 in the middle, and the tibial prosthesis 4 is rotatably connected to the rotating pin 36 through the connecting hole 43. A bushing 37 is provided between the connecting hole 43 and the rotating pin 36. The bushing 37 is provided with a positioning shoulder 371 that limits the relative position between the bionic joint connector 3 and the tibial prosthesis 4. The bushing 37 can be made of a low-friction material such as polytetrafluoroethylene to reduce friction during rotation and improve the joint's mobility. The positioning shoulder 371 can be an annular protrusion or a block protrusion, which can ensure the correct position of the tibial prosthesis 4 on the rotating pin 36 and prevent it from moving axially.

[0054] refer to Figures 12 to 13 The tibial prosthesis 4 has a movable groove 42 on the side away from the patellar groove at its end, which is adapted to the bionic joint connector 3. The movable groove 42 can provide space for the rotation of the bionic joint connector 3, making the joint movement smoother. The end of the tibial prosthesis 4 near the patellar groove has a suture hole 44 for fixing the patellar ligament. The path of the suture hole 44 is arc-shaped. This arc-shaped structure can better adapt to the direction of the patellar ligament and make it easier to fix the patellar ligament firmly to the prosthesis. The lower end of the tibial prosthesis 4 has a vertebral fitting groove 45 for docking and fixing with the tibia. The vertebral fitting groove 45 can be a conical groove or a trapezoidal groove, etc. It can fit tightly with the corresponding part of the tibia to achieve a stable connection between the tibial prosthesis 4 and the tibia.

[0055] The implementation principle of this embodiment is as follows: the connecting part 12 of the positioning plate 11 can be fixed to the femur; the biaxial rotation structure and ligament bionic mechanism of the bionic joint connector 3 enable the tibial prosthesis 4 to rotate horizontally while achieving knee flexion, which can better simulate the movement mode of the human knee joint, allowing children to still have a high degree of mobility during the bone growth stage, and can continuously provide stable support and flexible movement function as the bones develop. In particular, the ligament bionic mechanism can simulate the connecting ligaments at the human knee joint, which not only allows the prosthesis to have a high degree of mobility, but also provides stable support and flexible movement function for the prosthesis. The active area is restrained and positioned; the tibial pad 2 is detachably connected to the lower end of the positioning plate 11, and the tibial prosthesis 4 is rotatably connected to the rotating pin 36 through the connecting hole 43. This structural design can adapt to the rapid bone growth of children; during the bone growth process of children, the detachable tibial pad 2 can be easily replaced or adjusted according to the bone growth to ensure the fit between the prosthesis and the bone; at the same time, the prosthesis has a small trauma area, low cost, and high durability, which can reduce the harm to children's bodies, reduce the economic burden on families, and has high reliability for long-term use, which is conducive to the recovery and healthy growth of children during the rapid bone growth stage.

[0056] Example 2:

[0057] refer to Figures 14 to 15 The difference between this embodiment and Embodiment 1 is that the ligament bionic mechanism includes a sleeve 34 fixed in the docking hole 31, which can be installed by threaded fastening; the sleeve 34 has a blind hole 341 in the middle for connecting with the docking rod 13; the sleeve 34 can be made of a hard material, such as a high-strength metal like titanium alloy, or a cobalt-chromium-molybdenum alloy, which have good biocompatibility and strength. A buffer layer can also be covered on the outer wall of the sleeve 34, which can be made of a flexible material, such as polyethylene; the docking rod 13 is movably connected in the blind hole 341, and a pressure chamber 342 is formed between the bottom of the docking rod 13 and the blind hole 341; the positioning plate 11 The upper part is provided with a ventilation channel 131 arranged along the length of the docking rod 13. The ventilation channel 131 is connected to the air pressure chamber 342, and the positioning plate 11 is provided with a plug 132 for sealing the ventilation channel 131. The plug 132 can be a rubber plug or a threaded plug, etc. The air pressure of the air pressure chamber 342 can be adjusted by the plug 132 to adapt to different usage requirements. A sealing element is provided between the docking rod 13 and the blind hole 341 to ensure the airtightness of the air pressure chamber 342. The sealing element can be a rubber sealing ring or a silicone sealing gasket, etc., to prevent air leakage in the air pressure chamber 342 and ensure the normal operation of the ligament bionic mechanism. A sealing groove for installing the sealing element can be provided on the side wall of the docking rod 13 or the blind hole 341.

[0058] The implementation principle of this embodiment is as follows: the ventilation channel 131 facilitates the discharge of air between the blind hole 341 and the connecting rod 13 during the assembly of the connecting rod 13 and the blind hole 341, ensuring a smooth assembly process. After the connecting rod 13 and the blind hole 341 are assembled, the ventilation channel 131 is sealed by the plug 132. When the bionic joint connector 3 and the connecting rod 13 are relatively displaced, the air pressure change in the air chamber 342 generates an elastic restoring force, allowing the bionic joint connector 3 and the connecting rod 13 to return to their initial positions. This ensures that the convex arc-shaped articular surface 41 on the tibial prosthesis 4 and the concave arc-shaped articular surface 21 on the tibial pad 2 are always in contact, providing effective support and reducing the occurrence of collisions during knee joint movement due to gaps. This connection method allows for a wider range of relative movement between the connecting rod 13 and the blind hole 341, including axial and horizontal rotation, to achieve a bionic joint. The horizontal rotation of connector 3 allows the joint prosthesis to more accurately simulate the movement of the human knee joint, greatly improving the realism and naturalness of the movement. For pediatric patients, it provides greater range of motion than traditional prostheses during bone growth and continues to provide stable support and flexible movement as the bones develop. This effectively avoids the limb function limitations caused by insufficient range of motion in traditional prostheses, allowing pediatric patients to perform daily activities more naturally and comfortably during rehabilitation, reducing discomfort and psychological burden. In addition, this structural form also has the advantage of facilitating the adjustment and replacement of components later. During the growth and development of pediatric patients, the relative installation position between the femoral end prosthesis 1 and the tibial end prosthesis 4 can be adjusted, or components of the prosthesis can be replaced. The operation is more convenient, reducing maintenance costs and risks, and also improving the service life and applicability of the prosthesis.

Claims

1. A pediatric tibial tumor-type rotating hinge knee joint prosthesis, characterized in that, include: The femoral end prosthesis (1) includes a positioning plate (11) for a bionic femoral end epiphysis. The upper end of the positioning plate (11) is provided with a connecting part (12) for docking and fixing with the femur, and the lower end is provided with a vertically arranged docking rod (13). The tibial pad (2) is detachably connected to the lower end of the positioning plate (11), and the lower end of the tibial pad (2) is provided with a concave arc-shaped articular surface (21). The bionic joint connector (3) has a vertically arranged docking hole (31) at the upper end and a horizontally arranged rotating pin (36) at the lower end. The docking hole (31) is movably connected to the docking rod (13) through a ligament bionic mechanism. The ligament bionic mechanism allows the bionic joint connector (3) to rotate around the docking rod (13) and allows the bionic joint connector (3) to reciprocate along the axis of the docking rod (13) within a set distance range. The ligament bionic mechanism can generate an elastic restoring force when there is relative displacement between the bionic joint connector (3) and the docking rod (13) to drive the bionic joint connector (3) and the docking rod (13) back to their initial positions. The tibial prosthesis (4) is provided with a connecting hole (43), and the tibial prosthesis (4) is rotatably connected to the rotating pin (36) through the connecting hole (43); the upper end of the tibial prosthesis (4) is provided with a protruding arcuate joint surface (41) that is adapted to the concave arcuate joint surface (21); wherein, the protruding arcuate joint surface (41) and the concave arcuate joint surface (21) cooperate to form a rotational curved surface pair, allowing the tibial prosthesis (4) to rotate around the connecting rod (13) to realize the internal and external rotation of the lower leg; The upper end faces the femur, and the lower end faces the tibia; the tibial pad (2) is provided with a limiting groove (23) on the side away from the patellar groove to limit the rotation angle of the bionic joint connector (3); the bionic joint connector (3) is provided with abutment portions (35) on both sides that are adapted to the limiting groove (23); the abutment portions (35) and the limiting groove (23) form a deflection gap; the tibial end prosthesis (4) is provided with a movable groove (42) adapted to the bionic joint connector (3) on the side away from the patellar groove. The lower edge of the positioning plate (11) is provided with a snap-fit ​​groove (111), the edge of the tibial pad (2) is provided with a snap-fit ​​flange (24) that matches the snap-fit ​​groove (111), and the side of the positioning plate (11) near the patellar groove is provided with a first fastening hole (15) for fixing the tibial pad (2), and the tibial pad (2) is provided with a second fastening hole (22) that matches the first fastening hole (15). The connecting part (12) includes a medullary canal extension body disposed at the upper end of the positioning plate (11), and the upper end of the positioning plate (11) is provided with an anti-rotation boss (14) that can fit into the femur; the lower end of the tibial prosthesis (4) is provided with a vertebral groove (45) for docking and fixing with the tibia.

2. The pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 1, characterized in that, The ligament bionic mechanism includes a sleeve (34) fixed in the docking hole (31), the sleeve (34) being made of a flexible material, and a blind hole (341) for connecting with the docking rod (13) being provided in the middle of the sleeve (34); the docking rod (13) being fixed in the blind hole (341).

3. A pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 1, characterized in that, The ligament bionic mechanism includes a sleeve (34) fixed in the docking hole (31), and a blind hole (341) for connecting with the docking rod (13) is provided in the middle of the sleeve (34); the docking rod (13) is movably connected in the blind hole (341), and a pressure chamber (342) is formed between the docking rod (13) and the blind hole (341); the positioning plate (11) is provided with a ventilation channel (131) arranged along the length direction of the docking rod (13), the ventilation channel (131) is connected to the pressure chamber (342), and the positioning plate (11) is provided with a plug (132) for sealing the ventilation channel (131).

4. A pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 3, characterized in that, A sealing element (133) is provided between the docking rod (13) and the blind hole (341) to ensure the airtightness of the air pressure chamber (342).

5. A pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 2 or 3, characterized in that, The lower end of the bionic joint connector (3) is provided with a pin hole (32), which is connected to the docking hole (31); the docking hole (31) passes through the bionic joint connector (3) and forms a fixing hole (33) at the bottom of the bionic joint connector (3); the rotating pin (36) is detachably connected in the pin hole (32), and the rotating pin (36) is provided with a positioning hole (361) that is compatible with the sleeve (34) in the middle; the sleeve (34) passes through the pin hole (32) and the positioning hole (361) and is inserted into the fixing hole (33); the blind hole (341) extends into the positioning hole (361), and the docking rod (13) extends into the positioning hole (361).

6. A pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 1, characterized in that, The tibial prosthesis (4) has a suture hole (44) for fixing the patellar ligament at one end near the patellar groove; the suture hole (44) has an arc-shaped channel path.

7. A pediatric tibial tumor-type rotating hinge knee joint prosthesis according to claim 1, characterized in that, A bushing (37) is provided between the connecting hole (43) and the rotating pin (36), and a positioning shoulder lift (371) is provided on the bushing (37) to limit the relative position between the bionic joint connector (3) and the tibial end prosthesis (4).

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