Hinged 3D printed artificial ankle prosthesis

Abstract

The present invention belongs to the field of orthopedic medical devices, and provides a hinged 3D printed artificial ankle prosthesis, comprising a distal tibial prosthesis and a talar prosthesis, wherein the lower end of the distal tibial prosthesis is detachably connected to the talar prosthesis, the lower end of the distal tibial prosthesis is provided with a receiving groove recessed into the distal tibial prosthesis, the upper end of the talar prosthesis is provided with a lining hole matching the receiving groove, a detachable lining is provided in the lining hole, and an interference fit is formed between the lining and the lining hole. The beneficial effect of the present invention is that the pin shaft hole structure of the distal tibial prosthesis is used in conjunction with the pin shaft to ensure the rotation center and one degree of freedom (activity) of the ankle joint prosthesis, thereby improving the service life of the prosthesis.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a hinged 3D printed artificial ankle joint prosthesis. Background Art

[0002] The ankle joint is one of the most important load-bearing pulley joints in the human body. Its movement involves many tissue structures and its biomechanics are extremely complex. However, various severe traumas, tumors, and deformities can affect the function of the ankle joint. The various pressures faced by modern people, as well as some unhealthy living habits or blind overload exercise, have led to an increasing incidence of ankle joint dysfunction. Artificial customized tumor prosthesis replacement has become an important method for functional reconstruction of bone tumor resection during limb-saving surgery. For distal tibial tumors, the most commonly used prosthesis replacement treatment method is to remove the patient's distal tibia, and then use screws to directly fix the customized tibial prosthesis to the talus, and finally make the tibia and talus become one. Although this can achieve the expected support effect, it also makes the ankle joint lose a degree of freedom (activity). Such an ankle prosthesis has limited bionic motion function and poor activity performance in the body, resulting in poor recovery of ankle joint function after surgery and affecting the quality of life. Therefore, the design of the artificial ankle prosthesis is the key to affecting the bionic motion function and service life of the prosthesis. Summary of the invention

[0003] The purpose of the present invention is to provide a hinged 3D printed artificial ankle prosthesis with a simple structure, which can solve the technical problems existing in the prior art, and is particularly suitable for treating large-area defects of the distal tibia and repairing ankle joint replacement prostheses.

[0004] The technical solution of the present invention is: a hinged 3D printed artificial ankle prosthesis includes a distal tibial prosthesis and a talar prosthesis, the lower end of the distal tibial prosthesis is detachably connected to the talar prosthesis, the lower end of the distal tibial prosthesis is provided with a receiving groove recessed into the distal tibial prosthesis, the upper end of the talar prosthesis is provided with a lining hole matching the receiving groove, a detachable lining is provided in the lining hole, and the lining and the lining hole are interference fit.

[0005] The distal tibial prosthesis is formed by 3D printing. The distal tibial prosthesis includes a shaft prosthesis and a medullary pin prosthesis. The shaft prosthesis can be customized according to the patient's CT data to meet the patient's physiological structure. The medullary pin can also be customized according to the length of the remaining natural bone. The length is 40 to 120 mm. The medullary pin can be customized into a bone cement type or a biological type according to the patient's needs. The medullary pin plays a role in the initial fixation of the prosthesis.

[0006] The lower end of the distal tibial prosthesis is detachably connected to the talar prosthesis, and the two sides of the accommodating groove are connecting parts. The two connecting parts are provided with corresponding pin shaft holes. The pin shaft and the pin shaft hole, the liner hole, and the liner are coaxially arranged. The liner is provided with a first through hole allowing the pin shaft to pass through. The pin shaft is inserted into the pin shaft hole and the first through hole. There is a clearance fit between the first through hole and the pin shaft to ensure the freedom of the ankle joint in the anterior-posterior direction.

[0007] There is a clearance fit between the first through hole and the pin, that is, the inner diameter of the first through hole on the liner is larger than the outer diameter of the pin, forming a clearance fit. The clearance fit mentioned here is different from the interference fit, and does not mean that the clearance will cause the pin to shake in the first through hole.

[0008] The talar prosthesis comprises a talar prosthesis platform, the thickness of which is adjusted according to the height of the talar defect, the lining hole is arranged on the upper surface of the talar prosthesis platform, the talar prosthesis platform is provided with a first screw hole and a second screw hole, the skirt is a side boss on the lower surface of the talar prosthesis platform, in order to allow the talar prosthesis to be stuck on the residual talar prosthesis, the inner side of the skirt in contact with the residual talus needs to match the shape of the residual talus, the talar prosthesis skirt is provided with a third screw hole, and the talar prosthesis is connected and fixed to the residual talus through the screws and the three screw holes. The contact point between the screw hole and the trabecular structure, that is, the edge of the screw hole, adopts a solid structure to increase the strength of the screw hole and prevent the screw hole from breaking.

[0009] The edge contour of the talar prosthesis adopts a shape consistent with the residual talus to avoid interference with other bones or tissues, while ensuring the positioning of the talar prosthesis.

[0010] A shock-absorbing pad is provided on the talar prosthesis platform through an interference-fitted frustum structure to prevent the distal tibial prosthesis from colliding with the talar prosthesis platform when rotating around the axis.

[0011] The connecting part includes a first connecting part and a second connecting part, the first connecting part is provided with a first pin shaft hole, the second connecting part is provided with a second pin shaft hole, the pin shaft is provided with a pin groove, the second connecting part is provided with a pin hole, the axial direction of the pin hole and the axial direction of the second pin shaft hole are perpendicular to each other, and the pin hole and the second pin shaft hole are communicated, and the pin cooperates with the pin hole of the distal tibial prosthesis to play a role in preventing retreat and avoiding axial shaking.

[0012] The lower end of the talar prosthesis is provided with a skirt for facilitating positioning and fixing during installation, and the lining is designed with a skirt edge to avoid collision and wear between the distal tibial prosthesis and the talar prosthesis and prevent displacement in the axial direction.

[0013] The outer side of the first pin shaft hole is a pin shaft countersink, and the longitudinal section of the pin shaft countersink is polygonal. The shape of the pin shaft countersink matches the cap end structure of the pin shaft, which is beneficial to the positioning of the pin groove and can prevent rotation.

[0014] The lower ends of the first connection part and the second connection part are respectively provided with a first chamfer, and the specific angle of freedom of the ankle joint in the front-back direction can be adjusted by controlling the radius of the first chamfer.

[0015] The distal tibial prosthesis includes a shaft prosthesis and a medullary pin prosthesis. The shaft prosthesis part of the distal tibial prosthesis contacts the osteotomy surface of the residual natural bone and adopts a trabecular structure, which is conducive to bone ingrowth. The thickness of the trabecular structure is 2 to 5 mm. The cross-sectional size in contact with the natural bone is 1 to 3 mm larger than the cross-sectional size of the residual bone, which plays a supporting role to prevent the shaft from being inserted into the bone. The talar prosthesis adopts a 3D printed trabecular structure at the contact point with the residual talar osteotomy surface. The thickness of the trabeculae is 2 to 5 mm. The design is conducive to bone ingrowth and promotes secondary fixation of the prosthesis to bone tissue.

[0016] The advantages and positive effects of the present invention are as follows: due to the adoption of the above-mentioned technical scheme, the pin hole structure of the distal tibial prosthesis is used in conjunction with the pin to ensure the rotation center and degree of freedom of the ankle prosthesis. The contact between the diaphyseal prosthesis part of the distal tibial prosthesis and the osteotomy surface of the residual natural bone and the contact between the talar prosthesis and the osteotomy surface of the residual talus both adopt a 3D printed trabecular structure. This design is conducive to bone ingrowth and promotes the fixation of the prosthesis to bone tissue. The pin groove structure of the pin can cooperate with the pin hole of the distal tibial prosthesis through the pin to play a role in preventing retreat and avoiding axial shaking. The wear of the prosthesis is reduced by components such as the skirt, lining, and pin countersunk hole, thereby improving the service life of the prosthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of a distal tibial prosthesis in a hinged 3D printed artificial ankle prosthesis according to a specific embodiment 1 of the present invention;

[0018] Figure 2 It is a schematic diagram of the structure of a talar prosthesis of a hinged 3D printed artificial ankle joint prosthesis in specific embodiment 1 of the present invention;

[0019] Figure 3 It is a schematic diagram of the lining structure of a hinged 3D printed artificial ankle joint prosthesis according to a specific embodiment 1 of the present invention;

[0020] Figure 4 This is a schematic diagram of the pin structure of a hinged 3D printed artificial ankle joint prosthesis according to a specific embodiment 1 of the present invention;

[0021] Figure 5 1 is a schematic diagram of a pin structure of a hinged 3D printed artificial ankle joint prosthesis according to a specific embodiment 1 of the present invention;

[0022] Figure 6 yes Figure 2 A schematic diagram of a top view of a talar prosthesis of a hinged 3D printed artificial ankle prosthesis according to a specific embodiment 1 of the present invention after horizontal rotation of 180 degrees;

[0023] Figure 7 1 is a schematic diagram of the AA cross-sectional structure of a talar prosthesis of a hinged 3D printed artificial ankle joint prosthesis according to a specific embodiment 1 of the present invention;

[0024] Figure 8 1 is a schematic diagram of the overall structure of a hinged 3D printed artificial ankle joint prosthesis according to a specific embodiment 1 of the present invention;

[0025] Fig. 9 It is a schematic diagram of the cross-sectional structure of a hinge connection of a hinged 3D printed artificial ankle prosthesis according to specific embodiment 1 of the present invention.

[0026] Fig.10 It is a schematic diagram of the trabecular structure of the talar prosthesis of a hinged 3D printed artificial ankle prosthesis in specific embodiment 1 of the present invention.

[0027] In the figure:

[0028] 1. distal tibial prosthesis; 2. talar prosthesis; 3. pin; 4. lining; 5. pin; 6. medullary pin prosthesis; 7. diaphyseal prosthesis; 8. pin countersunk hole; 9. pin hole; 10. pin hole; 11. lining hole; 12. first screw hole; 13. pin cap end; 14. pin groove; 15. skirt; 16. edge contour; 17. first shock-absorbing pad; 18. cone; 19. first chamfer; 20. skirt; 21. first connecting part; 22. second connecting part; 23. second screw hole; 24. third screw hole; 25. first through hole; 26. second shock-absorbing pad; 27. trabecular structure. DETAILED DESCRIPTION

[0029] Specific embodiment: Figure 1-10 The present invention discloses a hinged 3D printed artificial ankle joint prosthesis, which is particularly suitable for repairing large-area defects of the distal tibia and replacing ankle joint prostheses.

[0030] The distal tibial prosthesis 1 is formed by 3D printing. The distal tibial prosthesis 1 includes a diaphyseal prosthesis 7 and a medullary pin prosthesis 6. The diaphyseal prosthesis 7 can be customized according to the patient's CT data to meet the patient's physiological structure, with a length of 50 to 100 mm. The medullary pin prosthesis 6 can also be customized according to the length of the remaining natural bone, with a length of 40 to 120 mm. The medullary pin prosthesis 6 can be customized to a bone cement type or a biological type according to the patient's needs, and the medullary pin plays the role of initially fixing the prosthesis.

[0031] The shape of each person's bones is different, and the cross-section is not a regular circle. The purpose of the present invention is to replicate a bone prosthesis that is completely consistent with the original natural bone shape, or a conical structure that is roughly similar to the original natural bone shape, based on the patient's CT data.

[0032] The diaphyseal prosthesis 7 of the distal tibial prosthesis 1 contacts the osteotomy surface of the remaining natural bone and adopts a trabecular structure 27, which is conducive to bone ingrowth and has a thickness of 2 to 5 mm. The cross-sectional dimension in contact with the natural bone is 1 to 3 mm larger than the cross-sectional dimension of the remaining bone, which plays a supporting role and prevents the diaphyseal prosthesis 7 from being inserted into the remaining natural bone.

[0033] The overall structure of the diaphyseal prosthesis 7 of the distal tibial prosthesis 1, except for the contact surface between the proximal end and the natural bone, is designed based on the patient's CT data to maintain consistency with the physiological structure of the natural bone. At the same time, the original size is 5% to 10% smaller than the natural bone. The reduced size is conducive to better coordination with the original muscle tissue and prevents the prosthesis from being too protruding and causing the overall size to be too large.

[0034] The talar prosthesis 2 is formed by 3D printing and connected and fixed to the residual talus by screws. The talar prosthesis 2 uses a 3D printed trabecular structure 27 at the contact point with the residual talar osteotomy surface. The thickness of the trabeculae is 2 to 5 mm. The design is conducive to bone ingrowth and promotes secondary fixation of the prosthesis and bone tissue. The thicker the trabecular structure 27 is, the more conducive it is to bone ingrowth, but too thick will affect the strength. The talar prosthesis 2 uses a 3D printed trabecular structure 27 at the contact point with the residual talar osteotomy surface. The thickness of the trabecular structure is adjusted according to the size of the space. Under the premise of ensuring strength, it can be of any thickness.

[0035] like Figure 2 As shown, the lower end of the distal tibial prosthesis 1 is detachably connected to the talar prosthesis 2. The lower end of the distal tibial prosthesis 1 is provided with a receiving groove recessed into the distal tibial prosthesis 1. The upper end of the talar prosthesis 2 is provided with a lining hole 11 matching the receiving groove. The lining hole 11 is provided with a detachable lining 4. The lining 4 and the lining hole 11 are interference fit. The lining 4 is installed in the lining hole 11, and two linings 4 are respectively inserted from both ends of the lining hole 11 of the talar prosthesis 2, as shown in FIG. Figure 8 and Fig. 9 As shown. The liner 4 is made of wear-resistant PEEK material, and there is an interference fit between the liner 4 and the talar prosthesis 2, ensuring that there is no relative displacement between the liner 4 and the talar prosthesis 2 to reduce wear. There is a clearance fit between the liner 4 and the pin 3 to ensure the freedom of the ankle joint in the anterior-posterior direction, and the freedom range is ± (15°~90°), and the specific angle can be adjusted by controlling the radius R of the first chamfer 19.

[0036] According to the prior art, those skilled in the art know that polyetheretherketone (PEEK) is a polymer composed of repeating units containing one ketone bond and two ether bonds in the main chain structure, and is a special polymer material. It has physical and chemical properties such as high temperature resistance and chemical corrosion resistance. It is a type of semi-crystalline polymer material that can be used as a high temperature resistant structural material and electrical insulation material, and can be composited with glass fiber or carbon fiber to prepare reinforcing materials. Generally, a type of polyarylether polymer obtained by condensation with aromatic dihydric phenol is used. This material has a large number of applications in the aerospace field, medical device field (as artificial bone to repair bone defects) and industrial field. It has high mechanical strength, high temperature resistance, impact resistance, flame retardancy, acid and alkali resistance, hydrolysis resistance, wear resistance, fatigue resistance, radiation resistance and good electrical properties.

[0037] The detachable and movable connection between the lower end of the distal tibial prosthesis 1 and the talar prosthesis 2 is that the two sides of the accommodating groove are connecting parts, and the two connecting parts are provided with corresponding pin shaft holes 9, the pin shaft 3 and the pin shaft hole 9, the lining hole 11, and the lining 4 are coaxially arranged, and the lining 4 is provided with a first through hole 25 allowing the pin shaft 3 to pass through, and the pin shaft 3 is inserted into the pin shaft hole 9 and the first through hole 25, and there is a clearance fit between the first through hole 25 and the pin shaft 3 to ensure the freedom of the ankle joint in the front-back direction, and there is a clearance fit between the first through hole 25 and the pin shaft 3, that is, The inner diameter of the first through hole 25 of the lining 4 is larger than the outer diameter of the pin 3, forming a clearance fit. The clearance fit mentioned here is different from the interference fit. The interference fit is that the two parts are tightly connected and cannot rotate, and the clearance fit is that they can rotate with each other. For example, here, the pin 3 can rotate in the first through hole 25 along the axial direction of the first through hole 25 without circumferential shaking. Through experiments, the structure in this specific implementation can achieve a degree of freedom range of ± (15° to 90°) in the front-back direction of the ankle joint by adjustment, and the specific angle can be adjusted by controlling the radius R of the first chamfer 19. The pin hole 9 structure of the distal tibial prosthesis 1 is used in conjunction with the pin 3 to ensure the rotation center and degree of freedom of the ankle joint prosthesis.

[0038] The head of the pin shaft 3 is chamfered to facilitate insertion. The pin shaft 3 is the rotating shaft of the ankle joint prosthesis and is made of cobalt-chromium-molybdenum material to ensure high strength and hardness and better wear resistance.

[0039] The talar prosthesis 2 includes a talar prosthesis platform. The thickness of the talar prosthesis platform is controllable (4 to 10 mm) and can be adjusted according to the height of the talar defect to ensure that it is basically consistent with the rotation center of the original ankle joint. The lining hole 11 is arranged on the upper surface of the talar prosthesis platform. The talar prosthesis platform is provided with a first screw hole 12 and a second screw hole 23. The skirt 15 is a boss on one side of the lower surface of the talar prosthesis platform. The skirt 15 of the talar prosthesis 2 is provided with a third screw hole 24. The thickness of the skirt 15 is greater than the thickness of the nut installed in the third screw hole 24 to ensure that the screws are firmly connected here to prevent screw disengagement. The talar prosthesis 2 is connected and fixed to the residual talus through screws and the three screw holes. The contact between the first screw hole 12, the second screw hole 23 and the trabecular structure 27 adopts a solid structure (such as Fig.10 According to the actual situation, because the solid thickness of the skirt 15 except the trabecular structure 27 is sufficient, the third screw hole 24 is strong enough and will not break the screw hole, and the thickness of the talar prosthesis platform is relatively thin to ensure strength, so the grids around the first screw hole 12 and the second screw hole 23 are made into solid.

[0040] The edge contour 16 of the talar prosthesis 2 adopts a shape consistent with the residual talus to avoid interference with other bones or tissues while ensuring the positioning of the talar prosthesis 2. Figure 6 The outermost circle of the contour line of the mid-talar prosthesis 2 shown in the top view.

[0041] like Figure 7 As shown, the shock-absorbing pad is knocked into the talar prosthesis platform surface through the interference fit cone 18 structure, and the material is PEEK (or polyethylene material, another embodiment of the preferred polyethylene material is selected from high molecular cross-linked polyethylene, high molecular cross-linked polyethylene, with high density and wear resistance. At the same time, the use of this material has a buffering effect. During exercise, it buffers the impact between various parts, imitating the buffering function of the human ankle joint itself), to prevent the distal tibial prosthesis from colliding with the talar prosthesis platform when rotating around the axis. Figure 2 As shown, the shock-absorbing pads are respectively a first shock-absorbing pad 17 and a second shock-absorbing pad 26 on the platform surface of the talar prosthesis and on both sides of the liner.

[0042] The connecting portion includes a first connecting portion 21 and a second connecting portion 22. The first connecting portion 21 is provided with a first pin shaft hole, and the second connecting portion 22 is provided with a second pin shaft hole. The pin shaft 3 is provided with a pin groove 14. The width of the pin groove 14 only needs to be slightly larger than the diameter of the pin 5, so that the pin 5 is convenient to insert into the pin groove 14. For example, the width of the pin groove 14 is slightly larger than the diameter of the pin 5 by 0.1~0.2mm. The slot opening direction of the pin groove 14 is perpendicular to the axial direction of the pin shaft 3. The second connecting portion 22 is provided with a pin hole 10. The axial direction of the pin hole 10 and the axial direction of the second pin shaft hole are perpendicular to each other, and the pin hole 10 and the second pin shaft hole are communicated. The pin 5 cooperates with the pin hole 10 of the distal tibial prosthesis 1 to prevent retreat and avoid axial shaking.

[0043] The lower end of the talar prosthesis 2 is provided with a skirt 15 for facilitating positioning and fixing during installation, which can facilitate positioning and fixing during the installation of the prosthesis. At the same time, the contact surface with the bone is designed as a trabecular structure 27, which is conducive to the secondary fixation of the prosthesis. The rectangular inside of the skirt 15 is in contact with the residual talus, just like the bottom of the talar prosthesis platform. It is a trabecular structure 27 of the same thickness, which is conducive to bone ingrowth. This structure has been marked with honeycomb section lines in all pictures. The front and back ends of the talar prosthesis platform are provided with a first screw hole 12 and a second screw hole 23. The skirt 15 of the talar prosthesis 2 is provided with a third screw hole 24. The talar prosthesis 2 is connected and fixed to the residual talus through screws and screw holes. The number of screw holes can be designed according to the actual situation of the patient. The angle of the screw hole is reasonably arranged on the prosthesis according to the number of screws required. In order to fix firmly, the screw holes are not parallel to each other in space, but form a cross angle in space. In order to fix firmly, this specific embodiment has 3 screw holes on the talar prosthesis, which are respectively connected through screws. The screws are connected (the first screw hole 12, the second screw hole 23 and the third screw hole 24). In order to fix firmly, the three screw holes are not parallel to each other in space, but form a cross angle in space. The first screw hole 12 and the second screw hole 23 are located at the front and rear ends of the talar prosthesis platform, and the opening direction is not perpendicular to the talar prosthesis platform, but is inclined on the talar prosthesis platform. The orthographic projection formed by the angle shows the extension lines of the first screw hole 12 and the second screw hole 23, which intersect.

[0044] like Figure 2 As shown, a third screw hole 24 is provided at a position slightly below the center of the skirt 15, and the angle of the third screw hole 24 can be adjusted according to actual conditions. The lining 4 is designed with a skirt 20, such as Figure 3As shown, after installation, one end of the skirt 20 abuts against one end of the lining hole 11, and the other side of the skirt 20 abuts against the inner side of the first pin shaft hole, that is, the skirt 20 is located between the lining hole 11 and the pin shaft hole 9, which can avoid collision and wear between the distal tibial prosthesis 1 and the talar prosthesis 2 and prevent displacement in the axial direction.

[0045] The outer side of the first pin hole is a pin countersink 8, the longitudinal section of the pin countersink 8 is polygonal, and the shape of the pin countersink 8 matches the structure of the pin cap end 13, which is beneficial to the positioning of the pin groove 14 and can prevent rotation.

[0046] The pin 3 described in this specific embodiment adopts a hexagonal cap structure, the pin countersunk hole 8 of the distal tibial prosthesis 1 is a hexagonal pin countersunk hole, and the pin cap end 13 adopts a hexagonal shape to cooperate with the hexagonal pin countersunk hole 8 of the distal tibial prosthesis 1. When the pin 3 is installed on the distal tibial prosthesis 1, the pin cap end 13 is completely in the pin countersunk hole 8, and the pin hole 10 of the distal tibial prosthesis 1 and the notch of the pin groove 14 are aligned, which is beneficial to the positioning of the pin groove 14 and can prevent rotation, thereby avoiding metal-to-metal friction, collision, wear, etc.

[0047] All parts of the movable connection are isolated from each other by lining 4 or shock-absorbing pads to avoid direct collision between metals, which may cause ion precipitation and trigger inflammation and infection.

[0048] The lower ends of the first connecting portion 21 and the second connecting portion 22 are respectively provided with a first chamfer 19 , and the specific angle of freedom of the ankle joint in the front-back direction can be adjusted by controlling the radius of the first chamfer 19 .

[0049] The prosthesis of the present application is suitable for treating large-area defects of the distal tibia and ankle joint replacement prosthesis. During the operation, the distal tibia of the patient is cut off, and then one end of the customized prosthesis is inserted into the proximal tibia of the healthy side, and the other end is fixed to the talus to replace the original ankle joint.

[0050] Installation process of a hinged 3D printed artificial ankle prosthesis:

[0051] Step 1: Insert two liners 4 into the talar prosthesis 2 from both sides of the liner hole 11 (this process is reversible, but it will be a little tight when taking it out);

[0052] Step 2: Insert the talar prosthesis 2 into the distal tibial prosthesis 1, and try to ensure that the two are coaxial (pay attention to the direction);

[0053] Step 3: Insert the pin 3 to the bottom, paying attention to the direction of the pin 3. At this time, the pin hole 10 of the distal tibial prosthesis 1 and the notch of the pin groove 14 are aligned;

[0054] Step 4: Insert the pin 5 into the pin hole 10, ensure that it is vertical, and then hammer it in with force until the upper surface of the pin 5 is coplanar with the front plane of the distal tibial prosthesis 1 (this step is an interference fit and is irreversible. Make sure that all the previous steps have been installed in place, and support the pin cap end 13 when knocking to prevent the pin 3 from withdrawing).

[0055] Specific embodiment 2: There are marking lines at the corresponding positions of the pin cap end 13 and the first connecting part 21. In the third step of the installation process of a hinged 3D printed artificial ankle prosthesis in specific embodiment 1, the pin 5 is inserted to the bottom, paying attention to the direction of the pin 3, so that the two marking lines are aligned. At this time, the pin hole 10 of the distal tibial prosthesis 1 and the notch of the pin slot 14 are aligned. The marking lines on the pin cap end 13 and the first connecting part 21 can be used to quickly and accurately select the installation angle and direction.

[0056] Specific embodiment 3: Based on specific embodiment 2, an indicator line is provided on the side of the pin 5, and the indicator line has an arrow to indicate the installation direction.

[0057] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0058] The above three embodiments of the present invention are described in detail, but the above contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A hinged 3D printed artificial ankle prosthesis, characterized in that: The support member comprises a distal tibial prosthesis and a talar prosthesis, the lower end of the distal tibial prosthesis being detachably connected to the talar prosthesis, the lower end of the distal tibial prosthesis being provided with a receiving groove recessed into the distal tibial prosthesis, the upper end of the talar prosthesis being provided with a lining hole matching the receiving groove, the lining hole being provided with a detachable lining, the lining and the lining hole being interference fit, the lower end of the distal tibial prosthesis being detachably connected to the talar prosthesis, the two sides of the receiving groove being connecting parts, the two connecting parts being provided with corresponding pin shaft holes, the pin shaft and the pin shaft hole, the lining hole and the lining being coaxially arranged, the lining being provided with a first through hole allowing the pin shaft to pass through, the pin shaft being inserted into the pin shaft hole and the first through hole, the first through hole and the pin shaft being clearance fit, thereby ensuring the freedom of the ankle joint in the anterior-posterior direction.

2. The hinged 3D printed artificial ankle prosthesis according to claim 1, characterized in that: The talar prosthesis includes a talar prosthesis platform, the thickness of which is adjusted according to the height of the talar defect, the lining hole is arranged on the upper surface of the talar prosthesis platform, the talar prosthesis platform is provided with a first screw hole and a second screw hole, the skirt is a boss on one side of the lower surface of the talar prosthesis platform, the skirt of the talar prosthesis is provided with a third screw hole, the talar prosthesis is connected and fixed to the residual talus by screws and screw holes, and a solid structure is adopted at the contact between the screw hole and the trabecular structure to increase the strength of the screw hole and prevent the screw hole from breaking.

3. The hinged 3D printed artificial ankle prosthesis according to claim 2, characterized in that: The edge contour of the talar prosthesis adopts a shape consistent with the residual talus to avoid interference with other bones or tissues, while ensuring the positioning of the talar prosthesis.

4. The hinged 3D printed artificial ankle prosthesis according to claim 3, characterized in that: A shock-absorbing pad is arranged on the talar prosthesis platform to prevent the distal tibial prosthesis from colliding with the talar prosthesis platform when the distal tibial prosthesis rotates around the axis.

5. The hinged 3D printed artificial ankle prosthesis according to claim 4, characterized in that: The connecting part includes a first connecting part and a second connecting part, the first connecting part is provided with a first pin shaft hole, the second connecting part is provided with a second pin shaft hole, the pin shaft is provided with a pin groove, the second connecting part is provided with a pin hole, the axial direction of the pin hole and the axial direction of the second pin shaft hole are perpendicular to each other, and the pin hole and the second pin shaft hole are communicated, and the pin cooperates with the pin hole of the distal tibial prosthesis to play a role in preventing retreat and avoiding axial shaking.

6. The hinged 3D printed artificial ankle prosthesis according to claim 5, characterized in that: The lower end of the talar prosthesis is provided with the skirt for facilitating positioning and fixing during installation, and the lining is designed with a skirt edge to avoid collision and wear between the distal tibial prosthesis and the talar prosthesis and prevent displacement in the axial direction.

7. The hinged 3D printed artificial ankle prosthesis according to claim 6, characterized in that: The outer side of the first pin shaft hole is a pin shaft countersink, and the shape of the pin shaft countersink matches the cap end structure of the pin shaft, which is beneficial to the positioning of the pin groove and can prevent the pin shaft and the distal tibial prosthesis from rotating.

8. The hinged 3D printed artificial ankle prosthesis according to claim 7, characterized in that: The lower ends of the first connection part and the second connection part are respectively provided with a first chamfer, and the specific angle of the degree of freedom of the ankle joint in the front-back direction is adjusted by controlling the radius of the first chamfer.

9. The hinged 3D printed artificial ankle prosthesis according to claim 8, characterized in that: The distal tibial prosthesis includes a shaft prosthesis and a medullary pin prosthesis. The shaft prosthesis part of the distal tibial prosthesis contacts the osteotomy surface of the residual natural bone and adopts a trabecular structure, which is conducive to bone ingrowth. The thickness of the trabecular structure is 2 to 5 mm. The cross-sectional size in contact with the natural bone is 1 to 3 mm larger than the cross-sectional size of the residual bone, which plays a supporting role to prevent the shaft from being inserted into the bone. The talar prosthesis adopts a 3D printed trabecular structure at the contact point with the residual talar osteotomy surface. The thickness of the trabeculae is 2 to 5 mm. The design is conducive to bone ingrowth and promotes secondary fixation of the prosthesis to bone tissue.

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