Artificial joint mold, artificial joint manufacturing method, and artificial joint

Abstract

The application discloses an artificial joint mold, a preparation method of an artificial joint and the artificial joint, and relates to the technical field of artificial joints. The mold comprises a female mold, which is provided with a recess position, and the bottom of the recess position is provided with a mounting hole; a male mold assembly, which comprises a pressing head; and a plug column, which is used for detachably assembling the mounting hole. In the processing process, the plug column can be firstly mounted in the recess position and assembled in the mounting hole, a first raw material layer is placed in the recess position, and after a first blank is formed by corresponding pressing heads, a hole is formed at the position of the plug column on the first blank; then, the plug column is replaced by an insert, the insert body of the insert can pass through the hole and extend into the mounting hole, the flange of the insert is lapped on the first blank, a second raw material layer is placed in the recess position, the flange is directly clamped between the first and second raw material layers by corresponding pressing heads, and the inner lining element formed by processing the raw material is directly and integrally embedded with the insert, so that the preparation is convenient.

Description

Technical Field

[0001] This invention relates to the field of artificial joint technology, and in particular to an artificial joint mold, a method for preparing an artificial joint, and an artificial joint. Background Technology

[0002] Artificial joints consist of a polymer liner and a metal component; this combination is recognized as the gold standard for joint load-bearing surfaces in the medical field. To ensure the long-term stability of the polymer liner within the artificial joint, complex limiting structures are typically designed and manufactured for the connection between the polymer liner and the metal component, resulting in high manufacturing costs. Furthermore, to ensure a stable and durable connection, the limiting structure at the connection point between the polymer liner and the metal component is designed with minimal margin, making installation more difficult.

[0003] In some existing technologies, polymer liner components are manufactured using molding to produce rough blanks, which are then finely processed to obtain products with complex limiting structures. This process involves multiple processing steps and significant raw material loss, resulting in high manufacturing costs. In joint replacement surgery, customized tools are used to fit the polymer liner components with metal components. This requires a high level of skill from the surgeon and carries certain risks during the installation process.

[0004] Therefore, how to facilitate the fabrication of artificial joints is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an artificial joint mold, a method for preparing an artificial joint, and an artificial joint that is easy to prepare.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of the present invention provides an artificial joint mold for manufacturing an artificial joint, the artificial joint including an inner liner element and an insert embedded in the inner liner element, a portion of the insert extending out of the inner liner element; the artificial joint mold includes: a female mold having a recess on its top surface for receiving a first material layer and a second material layer sequentially from bottom to top as raw materials for the inner liner element, and a mounting hole at the bottom of the recess; a male mold assembly including at least one pressure head for molding the first material layer to form a first blank, and at least one pressure head for molding the first blank and a second material layer above the first blank; a plug having a shape adapted to the mounting hole for detachable assembly into the mounting hole, and when the plug is assembled into the mounting hole, the top end structure of the plug extends upward into the recess to form an inner hole on the first blank corresponding to the shape of the insert; the mounting hole is sized to accommodate the protruding portion of the insert, for accommodating the portion of the insert protruding from the first blank after the plug is removed, and the middle portion of the insert extending into the inner hole.

[0008] In one exemplary embodiment, the mounting hole is a stepped hole, with the stepped surface facing the recess, the stepped surface supporting the plug, and the plug being able to disengage from above the mounting hole.

[0009] In one exemplary embodiment, the female mold is further provided with a guide groove, the male mold assembly includes a male mold, the pressure head is disposed on the male mold, and the male mold is further provided with a positioning guide post; during the process of the pressure head extending downward into the recess for molding, the positioning guide post and the guide groove are inserted and engaged for positioning.

[0010] In one exemplary embodiment, at least one of the inner surface of the recess, the surface of the plunger, and / or the surface of the pressure head is polished and / or coated; and / or, the cross-sectional shape of the plunger is adapted to the shape of the portion of the insert that passes through the mounting hole.

[0011] In one exemplary embodiment, at least one of the male molds in the male mold assembly is a first male mold, and the pressure head at its bottom is a first pressure head. A relief groove is formed on the bottom surface of the first pressure head. The first pressure head is used to extend into the recess before the second material layer is placed into the recess, and press down on the top surface of the first material layer in the recess. The relief groove can be sleeved on the outer side of the top of the plug.

[0012] In one exemplary embodiment, the depth of the relief groove is greater than the maximum depth to which the first pressure head extends into the recess during the molding process.

[0013] In one exemplary embodiment, at least one of the male molds in the male mold assembly is a second male mold, and the pressure head at its bottom is a second pressure head for pressing down on the top surface of the second raw material layer in the recess; the second pressure head has an arc-shaped surface for forming the friction surface of the artificial joint.

[0014] In one exemplary embodiment, the roughness of the friction surface is no greater than Ra0.5.

[0015] A second aspect of the present invention provides a method for preparing an artificial joint, using the artificial joint mold described above, comprising: assembling the plunger downwards into the mounting hole; pouring raw material into the recess to form a first raw material layer; molding the first raw material layer to form a first blank, wherein an inner hole is formed on the first blank at the position of the plunger; removing the plunger and sequentially inserting an insert into the inner hole and the mounting hole, wherein the overlap of the insert rests on the first blank; pouring raw material into the recess to form a second raw material layer, and molding the first blank and the second raw material layer into an inner liner element that fits with the insert.

[0016] In one exemplary embodiment, pouring raw material into the recess to form a first raw material layer includes: pouring raw material into the recess until it is flush with the top surface of the plug.

[0017] In one exemplary embodiment, the step of molding the first raw material layer to form a first blank includes: assembling a first male mold into the recess, and cold pressing the first raw material layer to form a first blank; in the cold pressing, the pressure range is 2-20 MPa, and the holding time ranges from 5-30 min.

[0018] In one exemplary embodiment, molding the first blank and the second raw material layer into an inner liner element that fits into the insert includes: assembling a second male mold into the recess, and hot-pressing the first blank and the second raw material layer to form an inner liner element that fits into the insert; in the hot pressing, the temperature range is 110-250℃, the pressure range is 0.5-20 MPa, and the holding time ranges from 30-300 min.

[0019] In one exemplary embodiment, the raw material is in the form of powder or granules.

[0020] A third aspect of the present invention provides an artificial joint, which is manufactured using the artificial joint preparation method described above; wherein the artificial joint includes an inner liner element and an insert embedded in the inner liner element, a portion of the structure of the insert extending out of the inner liner element, and the inner liner element is made of a polymer material.

[0021] In one exemplary embodiment, the polymer material is ultra-high molecular weight polyethylene with or without a crosslinking agent, or high molecular weight polyethylene, or PEEK, or ordinary polyethylene.

[0022] The present invention provides an artificial joint mold for manufacturing an artificial joint, the artificial joint including an inner liner element and an insert embedded in the inner liner element, wherein a portion of the insert extends out of the inner liner element.

[0023] The artificial joint mold includes: a female mold with a recess on its top surface for receiving a first material layer and a second material layer sequentially from bottom to top as raw materials for an inner liner element, and a mounting hole at the bottom of the recess; a male mold assembly including at least one pressure head for molding the first material layer to form a first blank, and at least one pressure head for molding the first blank and a second material layer above the first blank; a plug with a shape adapted to the mounting hole for detachable assembly into the mounting hole, and when the plug is assembled into the mounting hole, the top end structure of the plug extends upward into the recess to form an inner hole corresponding to the shape of the insert on the first blank; the mounting hole is sized to accommodate the protruding portion of the insert, for accommodating the portion of the insert protruding from the first blank after the plug is removed, and the middle portion of the insert extends into the inner hole.

[0024] The aforementioned artificial joint mold has mounting holes that can be used to avoid the portion of the insert that protrudes from the inner liner element. In conjunction with the recess that can place raw materials in layers and the plug that can form an inner hole, the insert and the inner liner element can be directly fixed and formed during the molding process of the raw material forming the inner liner element.

[0025] During the processing, the plunger can be first installed in the recess and assembled into the mounting hole. A layer of raw material is placed in the recess to form the first raw material layer. After the first blank is formed by pressing with the corresponding pressure head, the plunger position on the first blank forms an inner hole. Then, the plunger is replaced with an insert. The insert body can pass through the inner hole and extend into the mounting hole. The overlap of the insert is on the first blank. Then, another layer of raw material is placed in the recess to form the second raw material layer. It is further pressed by the corresponding pressure head, so that the overlap can be directly sandwiched between the first and second raw material layers. The inner lining element formed by the raw material processing is directly and integrally embedded with the insert, which is reliable. It does not require the inner lining element to be formed and then the insert to be assembled, which can save doctors' installation time and is convenient to prepare. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 A schematic diagram of the structure of an artificial joint according to a specific embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the insert according to a specific embodiment of the present invention; the dashed lines represent the perspective portion.

[0029] Figure 3 This is a first isometric view of the female mold according to a specific embodiment of the present invention;

[0030] Figure 4 This is a second axial side view of the female mold according to a specific embodiment of the present invention;

[0031] Figure 5 Axonometric view of the plunger in a specific embodiment of the present invention;

[0032] Figure 6 This is a first axonometric view of the first male mold provided in a specific embodiment of the present invention;

[0033] Figure 7 This is a second axonometric view of the first male mold provided in a specific embodiment of the present invention;

[0034] Figure 8 This is a first axonometric view of the second male mold according to a specific embodiment of the present invention;

[0035] Figure 9 This is a second axonometric view of the second male mold provided in a specific embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of the assembly process of the first male mold in a specific embodiment of the present invention;

[0037] Figure 11 This is a schematic diagram of the assembly process of the second male mold in a specific embodiment of the present invention;

[0038] Figure 12 A schematic diagram of the structure of a female mold with two recesses and a male mold that matches the two recesses respectively, according to a specific embodiment of the present invention;

[0039] Figure 13 This is a flowchart illustrating a method for preparing an artificial joint according to a specific embodiment of the present invention.

[0040] Figure label:

[0041] Inner liner element 11, first raw material layer 111, second raw material layer 112, inner hole 113, first blank 114;

[0042] Insert 12, insert head 121, insert tail 122, overlap 123;

[0043] Female mold 21, recess 211, guide groove 212, mounting hole 213, stepped surface 214, main structure 215, base plate 216;

[0044] Plug 22;

[0045] First male mold 23, first positioning guide post 231, first pressure head 232, first end plate 233, relief groove 234;

[0046] Second male mold 24, second positioning guide post 241, second pressure head 242, second end plate 243, arc surface 244. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0048] The core of this invention is to provide an artificial joint mold, a method for preparing an artificial joint, and an artificial joint that is easy to prepare.

[0049] The artificial joint mold provided by this invention can be used to manufacture artificial joints or parts thereof. Figure 1 and Figure 2 As shown, it is an artificial joint that can be made using the artificial joint mold in this application, specifically a knee joint pad, including an inner liner element 11 and an insert 12 embedded in the inner liner element 11. A portion of the insert 12 extends out of the inner liner element 11, and the structure on the artificial joint that engages with and locks with a metal tray is located on the portion of the insert 12 that extends out of the inner liner element 11.

[0050] For example, the inner lining element 11 is a plastic element, specifically a polymer inner lining element. The raw material of the inner lining element 11 can be ultra-high molecular weight polyethylene, and can be cross-linked powder (e.g., ultra-high molecular weight polyethylene containing a cross-linking agent) or non-cross-linked powder. Alternatively, it can also be high molecular weight polyethylene, PEEK (polyether ether ketone), ordinary polyethylene, etc.

[0051] For example, the insert 12 is preferably made of a metallic material, forming a metal insert or metal element. Figure 2 As shown, the insert head end 121 of insert 12 can be locked with a metal tray to form a robust artificial joint. The insert tail end 122 of insert 12 can be embedded into the inner liner element 11 and integrally formed with the inner liner element 11 to form a robust and stable artificial joint. Specifically, as shown... Figure 11As shown, the insert 12 includes an insert body and an overlap 123 protruding from the outer periphery of the insert body. The overlap 123 and the tail end of the insert body form the insert tail end 122, which is used to be embedded inside the inner liner element 11. The head end of the insert body is the insert head end 121, which extends out of the inner liner element 11.

[0052] For a specific embodiment of the artificial joint mold provided by this invention, please refer to [the following text is a separate, unrelated sentence:] Figures 3 to 11 It includes a female mold 21, a plug 22, and a male mold assembly.

[0053] like Figure 3 and Figure 4 As shown, the top surface of the female mold 21 has a recess 211, and one or more recesses 211 can be provided. The recess 211 is used to place the raw material forming the inner lining element 11. Specifically, the recess 211 receives the first raw material layer 111 and the second raw material layer 112 from bottom to top, serving as the raw material for the inner lining element 11. The inner surface of the recess 211 is polished and coated to make it smooth, which facilitates rust prevention and demolding.

[0054] The raw material placed in the recess 211 to form the liner element 11 is powder, but in other embodiments it can also be granules. For example, the raw material can be ultra-high molecular weight polyethylene (UHMWPE), which has excellent wear resistance, mechanical properties, biocompatibility and other properties. It is used in the field of artificial joint replacement as a load-bearing material for artificial joint liner, and can be made into UHMWPE joint prostheses with good mechanical properties.

[0055] Among them, such as Figure 4 and Figure 5 As shown, a mounting hole 213 is provided at the bottom of the recess 211. Specifically, one or more holes can be provided, preferably two or more. For example... Figure 11 As shown, the mounting hole 213 can receive the insert head end 121 of the insert 12 extending out of the inner liner element 11 after the insert 12 is installed in the recess 211.

[0056] The male mold assembly includes one or more pressure heads. For example... Figure 10 As shown, at least one press head is used to mold the first raw material layer 111 to form a first blank 114. Typically, after the first raw material layer 111 is molded to form the first blank 114, its height becomes thinner. Furthermore, as... Figure 11 As shown, at least one press head is used to mold the first blank 114 and the second raw material layer 112 above the first blank 114.

[0057] The plunger 22 is designed for detachable assembly (e.g., insertion) into the mounting hole 213, and a portion of the plunger 22 extends into the recess 211. The plunger 22 is used to form an inner hole 113 for the insert 12 to pass through the liner element 11, specifically, see reference... Figure 10When the plunger 22 is assembled into the mounting hole 213, the top end structure of the plunger 22 extends upward into the recess 211 to form an inner hole corresponding to the shape of the insert 12 on the first blank 114 molded from the first raw material layer 111. Furthermore, the mounting hole 213 is adapted to the shape and size of the plunger 22 and can directly serve as a positioning structure for the plunger 22, facilitating its positioning within the recess 211. For example, the mounting hole 213 can be a round hole, a polygonal hole, or other irregularly shaped hole.

[0058] Additionally, refer to Figure 11 The mounting hole 213 is sized to accommodate the protruding portion of the insert 12. After the plug 22 is removed from the mounting hole 213, the portion of the insert 12 protruding from the first blank 114 can be accommodated. This portion is also the portion protruding from the inner liner element 11 after the artificial joint is formed. The middle part of the insert 12 extends into the inner hole of the first raw material layer 111, and the overlapping edge 123 of the top of the insert 12 rests on the top surface of the first blank 114. The overlapping edge 123 is sandwiched between the first raw material layer 111 and the second raw material layer 112, so that the insert 12 and the inner liner element 11 can be directly connected after the powder is formed.

[0059] In the aforementioned artificial joint mold, the mounting hole 213 can be used to avoid the part of the insert 12 that protrudes from the inner liner element 11. In conjunction with the recess 211 that can place raw materials in layers and the plug 22 that can form the inner hole 113, the insert 12 and the inner liner element 11 can be directly fixed and formed during the molding process of the raw material forming the inner liner element 11.

[0060] During the processing, the plug 22 can be installed in the recess 211 and assembled into the mounting hole 213. A layer of raw material is placed in the recess 211 to form a first raw material layer 111. After the first blank 114 is formed by pressing with the corresponding pressure head, the position of the plug 22 on the first blank 114 forms an inner hole 113. Then, the plug 22 is replaced with an insert 12. The insert body of the insert 12 can pass through the inner hole 113 and extend into the mounting hole 213. The overlap 123 of the insert 12 overlaps the first blank 114. Then, another layer of raw material is placed in the recess 211 to form a second raw material layer 112. After further pressing with the corresponding pressure head, the overlap 123 can be directly sandwiched between the first raw material layer 111 and the second raw material layer 112. The inner lining element 11 formed by the raw material processing is directly and integrally embedded with the insert 12, which is reliable. It is not necessary to assemble the insert 12 after the inner lining element 11 is formed, which can save doctors' installation time and is convenient to prepare.

[0061] In some embodiments, such as Figure 2 , Figure 10 and Figure 11 As shown, the mounting hole 213 is a stepped hole, and the stepped surface 214 faces the recess 211. That is to say, in the stepped hole, the larger diameter part is close to the recess 211, and the smaller diameter part is far away from the recess 211.

[0062] The stepped surface 214 supports and positions the plunger 22 and the insert 12, preventing them from dislodging downwards from the mounting hole 213 and ensuring machining accuracy. Additionally, the plunger 22 can dislodge from above the mounting hole 213.

[0063] In some embodiments, such as Figure 10 As shown, the mounting hole 213 is a through hole that penetrates the female mold 21, which facilitates the demolding of the plug 22 and the artificial joint.

[0064] In some embodiments, such as Figure 10 As shown, the mounting hole 213 is located in the middle of the groove bottom opposite to the opening of the recess 211, so that the insert 12 is substantially embedded in the center of the inner liner element 11.

[0065] In some embodiments, the plunger 22 is a metal pillar. The surface of the plunger 22 may be polished or coated to make it smooth, facilitating separation from the first blank 114. The plunger 22 may be a circular, polygonal, or irregularly shaped elongated metal block, specifically adapted to the shape of the insert body, so that after the plunger 22 is removed from the inner hole 113 of the first blank 114, the outer peripheral surface of the insert body fits into the inner hole 113 of the first blank 114.

[0066] In addition, the cross-sectional shape of the corresponding position of the plunger 22 can also be adapted to the shape of the part of the insert 12 that passes through the mounting hole 213, so that the insert 12, the plunger 22 and the mounting hole 213 can have the same assembly relationship.

[0067] Furthermore, the male mold assembly may include one or more male molds, each of which may include one or more pressure heads for extending downward into the recess 211 to perform molding. The surface of the pressure head may be polished or coated to make it smooth, facilitating rust prevention and demolding.

[0068] In some embodiments, the male mold assembly includes multiple male molds, each with a different pressure head height, for sequentially pressing powder at different depths in the recess 211. For example... Figure 10 and Figure 11 There are two male molds, namely the first male mold 23 and the second male mold 24. After the powder is poured in for the first time, it is pressed by the first male mold 23. After the powder is poured in for the second time, it is pressed by the second male mold 24. The shape of the pressing head of each male mold can also be different.

[0069] In some embodiments, such as Figure 4 , Figure 6 and Figure 8As shown, the female mold 21 is also provided with a guide groove 212, and the male mold is also provided with a positioning guide post. One or more guide grooves 212 and positioning guide posts can be provided, and they are arranged in equal numbers and interlocked one-to-one. The positioning guide posts and guide grooves 212 are used for positioning during the molding process of the male and female molds 21. During the process of the pressure head extending into the recess 211, the positioning guide posts and guide grooves 212 interlock to position and guide, ensuring that the pressure head can smoothly enter the selected position in the recess 211.

[0070] Specifically, the first male mold 23 has a first end plate 233, and a first pressure head 232 and a plurality of first positioning guide posts 231 are provided on one side of the first end plate 233; the second male mold 24 has a second end plate 243, and a second pressure head 242 and a plurality of second positioning guide posts 241 are provided on one side of the second end plate 243. The plurality of first positioning guide posts 231 and the plurality of second positioning guide posts 241 can be inserted and positioned correspondingly to the plurality of guide grooves 212 on the female mold 21.

[0071] In some embodiments, such as Figure 6 and Figure 7 As shown, the pressure head of the first male mold 23 is the first pressure head 232, which matches the recess 211 of the female mold 21. It is used to press the powder around the plug 22 in the recess 211 into the first blank 114 when the plug 22 is installed in the mounting hole 213.

[0072] For example, a relief groove 234 is provided on the first pressure head 232. After the first pressure head 232 extends into the recess 211, the relief groove 234 can be sleeved on the outer side of the top of the plug 22 to prevent the plug 22 from contacting the first pressure head 232 during the molding process, so that the raw material does not receive the due pressure.

[0073] Specifically, such as Figure 10 As shown, after the plunger 22 is installed in the mounting hole 213 and powder is placed in the recess 211 to form the first raw material layer 111, and before the second raw material layer 112 is placed in the recess 211, the first male mold 23 is assembled. The first pressure head 232 continuously extends into the recess 211. The relief groove 234 of the first male mold 23 is fitted around the outside of the plunger 22. The first blank 114 is formed by the cooperation of the plunger 22 with the female mold 21 and the first male mold 23. The sidewall of the relief groove 234 fits snugly with the sidewall of the plunger 22. During the process of the first pressure head 232 extending into the recess 211, the relief groove 234 moves along the plunger 22, pressing down on the powder that is attached to the plunger 22 to ensure that the powder around the plunger 22 can be compacted and formed.

[0074] For example, the relief groove 234 cooperates with the plug 22, and the depth of the relief groove 234 can be greater than the travel of the first pressure head 232 in the recess 211, that is, greater than the maximum depth of the first pressure head 232 extending into the recess 211 during the molding process, so as to avoid physical collision between the plug 22 and the first pressure head 232 after the first pressure head 232 moves into place, and ensure that the plug 22 will not affect the molding process of the first raw material layer 111.

[0075] For example, since the surface of the first blank 114 facing the opening of the recess 211 still needs to be further processed and the shape requirement is low, the first pressure head 232 enters the recess 211 through the opening of the recess 211. The bottom surface of the first pressure head 232 facing the bottom of the recess 211 is a plane, which facilitates the processing of the first pressure head 232.

[0076] In some embodiments, such as Figure 8 and Figure 11 As shown, the pressure head of the second male mold 24 is the second pressure head 242, which matches the recess 211. It is used to heat press and fix all the powder into one piece after the first blank 114 is placed in the insert 12 and the second raw material layer 112 is also placed in the recess 211, so that the powder covering the head end 121 of the insert is also fixed and formed.

[0077] For example, the second pressure head 242 has an arc-shaped surface 244, which can specifically match the shape of the friction surface of the artificial joint. In this case, through the cooperation of the second pressure head 242 and the female mold 21, an artificial joint with a surface shape that meets the requirements can be directly processed, reducing the number of reprocessing steps.

[0078] The arc-shaped surface 244 is used to form the friction surface of the artificial joint. To ensure that the friction surface is extremely smooth, the roughness of the friction surface can be controlled to be no greater than Ra0.5, preferably no greater than Ra0.1.

[0079] In some embodiments, to improve processing efficiency, the female mold 21 is provided with multiple recesses 211, and multiple pressure heads are provided to match the recesses 211 on the female mold 21. For example, the first male mold 23 is provided with a first pressure head 232 equal in number to the recesses 211, and the second male mold 24 is provided with a second pressure head 242 equal in number to the recesses 211, so that the powder in each recess 211 and the corresponding insert 12 can be integrally formed simultaneously. Figure 12 As shown, a female mold 21 is provided with two recesses 211, a first male mold 23 is provided with two first pressure heads 232, and a second male mold 24 is provided with two second pressure heads 242. Through one pressing operation of the first male mold 23, its two first pressure heads 232 can simultaneously mold the first raw material layer 111 in the two recesses 211 respectively. Through one pressing operation of the second male mold 24, its two second pressure heads 242 can simultaneously mold the first blank 114 and the second raw material layer 112 in the two recesses 211 respectively.

[0080] In some embodiments, such as Figure 12 As shown, the female mold 21 includes a base plate and a main structure. The main structure has through holes running vertically through it. The base plate covers the bottom of each through hole to form a recess 211. At this time, mounting holes 213 are formed in the base plate. The separate structure facilitates processing. In other embodiments, the female mold 21 can also be a one-piece molded structure.

[0081] In addition to the artificial joint molds described above, the present invention also provides a method for preparing an artificial joint. This method can be applied to the artificial joint molds in the above embodiments. For example, this method can be used for molding ultra-high molecular weight polyethylene knee joint pads.

[0082] A specific embodiment of the method for preparing an artificial joint provided by the present invention is as follows: Figure 13 As shown, it includes the following steps:

[0083] S1: Assemble the plunger 22 downwards into the mounting hole 213.

[0084] At this time, as Figure 10 As shown in the diagram, during the manufacturing process, the recess 211 is located on the top surface of the female mold 21, and the mounting hole 213 is located at the bottom of the recess 211. Raw material is injected into the recess 211 from top to bottom. In addition, the top of the plug 22 protrudes from the bottom surface of the recess 211 so that the inner liner element 11 can form an inner hole 113 through which the insert 12 passes.

[0085] S2: Pour raw material into the recess 211 to form the first raw material layer 111.

[0086] S3: The first raw material layer 111 is molded to form a first blank 114, and an inner hole 113 is formed on the first blank 114 at the position of the plug 22.

[0087] It should be noted that the height of the first blank 114 is related to the amount of raw material added to form the first raw material layer 111. The purpose of the plug 22 is to form an inner hole 113 in the first blank 114 for placing the insert 12. In addition, since the amount of raw material is fixed, the height of the first blank 114 is also fixed and is independent of the height of the insert 12. Furthermore, the amount of material poured in the first pour to form the first raw material layer 111 is determined according to the product model and process.

[0088] In some embodiments, in S2, raw material is poured into the recess 211 to form a first raw material layer 111. The top surface of the first raw material layer 111 is flush with the top surface of the plug 22. The top surface of the plug 22 can be used as the positioning surface in this step. This height limitation can prevent the raw material from blocking the top surface of the plug 22 and facilitate the demolding of the plug 22.

[0089] In some embodiments, the amount of raw material poured into the recess 211 to form a raw material layer in each step can be pre-weighed and a set weight of raw material can be selected for pouring.

[0090] In some embodiments, each time a raw material layer is poured into the recess 211 to form a raw material layer, the upper surface of the raw material layer can be adjusted to a flat state to ensure that the pressure is evenly distributed in all places, or to facilitate the control of the required pressure in each place.

[0091] In some embodiments, to form the first blank 114, the first male mold 23 can be assembled into the recess 211, and then the first raw material layer 111 can be cold-pressed to form the first blank 114, after which the first male mold 23 can be removed. During cold pressing, the mold is placed in a hydraulic press / molding press. By using cold pressing technology, the raw materials in the first raw material layer 111 can be mechanically interlocked to form a dense body, which is then shaped into the first blank 114, facilitating the demolding of the plunger 22 and the installation of the insert 12. Exemplarily, the parameters of the cold pressing process can be: a pressure range of 2-20 MPa and a holding time range of 5-30 min, so that after the dense first blank 114 is formed, the raw material is not easily collapsed after the plunger 22 is removed. For example, in the molding process of an ultra-high molecular weight polyethylene knee joint pad, in step S3, a first male mold 23 is used in conjunction with a female mold 21 for cold pressing at a pressure of 5 MPa for 10 minutes, forming a first blank 114 from the first raw material layer 111 in the recess 211. Furthermore, due to the downward pressure, the top surface of the first blank 114 is lower than the top surface of the plunger 22. Specifically, after pressing the start button of the hydraulic press / molding machine for cold pressing, the selected program is entered, reaching the set pressure and running for the set holding time.

[0092] S4: Remove the plunger 22 and insert the insert 12 into the inner hole 113 and the mounting hole 213 in sequence. The overlap 123 of the insert 12 overlaps above the first blank 114.

[0093] In some embodiments, the separation process between the plunger 22 and the first blank 114 is as follows: the first blank 114 is formed under pressure, and its height is thinner than the first raw material layer 111. When the first male mold 23 is removed, the plunger 22 can be taken away from the top. When the mounting hole 213 is a through hole that penetrates the female mold 21 from top to bottom, the plunger 22 can also be pushed out from bottom to top and then taken away.

[0094] In some embodiments, such as Figure 11As shown, after the first blank 114 is formed, and the first male mold 23 and the plug 22 are removed from the female mold 21 in sequence, the inner hole 113 formed by the plug 22 on the first blank 114 is exposed. The overlap 123 of the insert 12 is larger than the inner hole 113 and cannot pass through. The insert 12 is placed into the inner hole 113 of the first blank 114 from top to bottom until the overlap 123 of the insert 12 is on the top surface of the first blank 114, and the head end 121 of the insert extends out of the bottom surface of the first blank and is inserted into the mounting hole 213.

[0095] In some embodiments, the outer peripheral surface of the insert body fits into the wall of the inner hole 113 of the first blank 114.

[0096] In some embodiments, the stepped surface 214 of the mounting hole 213 may also support the insert 12 to prevent the insert 12 from being subjected to excessive pressure during subsequent processing, which could damage the overlap 123 or cause it to come out of the inner hole 113.

[0097] S5: Pour raw material into the recess 211 to form a second raw material layer 112, and mold the first blank 114 and the second raw material layer 112 into an inner liner element 11 that fits into the insert 12.

[0098] At this time, as Figure 11 As shown, in S4, raw materials are poured into the recess 211 to form a second raw material layer 112. The raw materials of the first blank 114 and the second raw material layer 112 are combined in this step to form an integral inner lining element 11, which is directly fixed to the overlap 123 of the insert 12 sandwiched between the first blank 114 and the second raw material layer 112. Due to the obstruction of the first blank 114, the overlap 123 cannot pass through the inner hole 113, thus realizing the integral fixing of the inner lining element 11 and the insert 12.

[0099] In some embodiments, a hot pressing process can be used to form the inner liner element 11 that fits into the insert 12. Specifically, this can be achieved by assembling the second male mold 24 and the female mold 21 using a molding press or a hot press. During hot pressing, heating and vacuuming functions are activated. After hot pressing, the raw materials in the first blank 114 and the second raw material layer 112 can undergo plastic deformation and diffusion sintering to form an integral structure. In addition, the same molding press can be used to switch from cold pressing to hot pressing without changing equipment.

[0100] Specifically, during hot pressing in S5, the hot pressing parameters include: a temperature range of 110-250℃, a pressure range of 0.5-20 MPa, and a holding time range of 30-300 min. One type of powder material has a heat distortion temperature of 85℃ and a melting point of 130-136℃. Temperatures within this range accelerate material melting, easily forming a dense plastic body under external pressure, which can enclose the insert 12, forming a good solid cavity. Furthermore, during hot pressing, too low a pressure will prolong the process time, while too high a pressure will waste resources. Additionally, during hot pressing, too low a holding time may affect product performance, resulting in incomplete crystallization of the formed solid; too high a holding time will prolong the process time, reduce yield, and increase costs. More specifically, during hot pressing, the temperature is 150-250℃, the pressure is 2-20 MPa, and the holding time is 30-300 min.

[0101] Specifically, during hot pressing in S5, a molding press equipped with both heating and cooling systems can be used. To achieve the required cooling rate control, oil heating is preferred, as it is easy to integrate with the cooling system, allowing for simpler and more precise temperature control of the mold. Electric heating can also be used, but this requires an additional independent coolant system for the mold to control cooling, making implementation more complex. The mold does not require separate preheating before hot pressing; it can be heated from room temperature.

[0102] For example, in the molding process of an ultra-high molecular weight polyethylene knee joint pad, in step S5, after assembling the second male mold 24, the artificial joint mold is placed in a hot press and held at a pressure of 1.2 MPa for 70 minutes. Simultaneously, the temperature of the hot press rises from room temperature to 120°C within 40 minutes and is held for 30 minutes. Afterward, the hot press pressure is reduced to 0.6 MPa and held for 240 minutes. Simultaneously, the temperature of the hot press rises from 120°C to 210°C within 90 minutes and is held for 60 minutes. Then, the temperature of the hot press drops from 210°C to 120°C within 90 minutes. Afterward, the hot press pressure is reduced to 1.2 MPa and held for 150 minutes. Simultaneously, the temperature of the hot press is held at 120°C for 60 minutes and then drops from 120°C to room temperature within 90 minutes.

[0103] In addition, after hot pressing is completed, the artificial joint mold is removed from the hot press, the second male mold 24 is separated from the female mold 21, and the artificial joint is separated from the female mold 21 using a tool and removed. For example, the mounting hole 213 is a through hole that penetrates the female mold 21, and the finished artificial joint is ejected from the bottom of the female mold 21 through the mounting hole 213 using a tool.

[0104] The artificial joint preparation method provided in this invention adopts a layered placement of raw materials, which can fix the inner liner element 11 and the overlap 123. With the help of the inner hole 113 formed by the plug 22, the insert 12 can pass through the inner liner element 11. This can solve the problem of doctors having difficulty installing polymer inner liner elements in artificial joint replacement surgery. The entire artificial joint preparation process is simple and fast, with a significant reduction in manufacturing steps, a significant reduction in the amount of manufacturing materials, and a reduction in manufacturing costs. During the preparation process, the friction surface of the artificial joint has excellent flatness due to the contraction of surface tension when the material undergoes physical changes. After molding, the surface roughness is extremely low and the surface is smooth. No further processing of the appearance is required after molding. It is convenient for doctors to operate and has good bonding force with the metal tray. It can be applied to the field of orthopedic implant manufacturing technology to realize the molding of ultra-high molecular weight polyethylene / highly cross-linked ultra-high molecular weight polyethylene knee joint liner.

[0105] Furthermore, this invention also provides an artificial joint manufactured using the above-described method for preparing an artificial joint. This artificial joint exhibits good locking performance with the metal tray, stable mechanical properties, and simplifies operation for surgeons, reducing surgical time.

[0106] Specifically, the inner lining element 11 is made of a polymer material, which can be ultra-high molecular weight polyethylene, or ultra-high molecular weight polyethylene containing a crosslinking agent, or high molecular weight polyethylene, or PEEK, or ordinary polyethylene.

[0107] It should be noted that when an element is referred to as "fixing" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as "connecting" another element, it can be directly connected to the other element or there may be an intervening element. Furthermore, in the description of this invention, unless otherwise stated, "multiple," "multiple roots," and "multiple groups" mean two or more.

[0108] The terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0110] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0111] The artificial joint mold, artificial joint, and its preparation method provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An artificial joint mold, characterized in that, It is used to prepare an artificial joint, the artificial joint including an inner liner element (11) and an insert (12) fitted into the inner liner element (11), a portion of the structure of the insert (12) extending out of the inner liner element (11). The artificial joint mold includes: The female mold (21) has a recess (211) on its top surface, which is used to receive the first material layer (111) and the second material layer (112) from bottom to top, so as to serve as the material of the inner lining element (11), and the bottom of the recess (211) has a mounting hole (213). A male mold assembly, comprising at least one pressure head for molding the first raw material layer (111) to form a first blank (114), and comprising at least one pressure head for molding the first blank (114) and a second raw material layer (112) above the first blank (114). A plunger (22) is adapted to the mounting hole (213) for detachable assembly in the mounting hole (213). When the plunger (22) is assembled in the mounting hole (213), the top end structure of the plunger (22) extends upward into the recess (211) to form an inner hole (113) on the first blank (114) corresponding to the shape of the insert (12). The mounting hole (213) is sized to accommodate the protruding portion of the insert (12) for accommodating the portion of the insert (12) protruding from the first blank (114) after the plunger (22) is removed, and the middle part of the insert (12) extends into the inner hole (113).

2. The artificial joint mold according to claim 1, characterized in that, The mounting hole (213) is a stepped hole, and the stepped surface (214) faces the recess (211). The stepped surface (214) can support the plug (22), and the plug (22) can be dislodged from above the mounting hole (213).

3. The artificial joint mold according to claim 1, characterized in that, The female mold (21) is also provided with a guide groove (212), the male mold assembly includes a male mold, the pressure head is provided on the male mold, and the male mold is also provided with a positioning guide post; During the molding process, the positioning guide post and the guide groove (212) are inserted and engaged for positioning when the pressure head extends downward into the recess (211).

4. The artificial joint mold according to claim 1, characterized in that, At least one of the inner surface of the recess (211), the surface of the plunger (22), and / or the surface of the pressure head is polished and / or coated; and / or, The cross-sectional shape of the plunger (22) is adapted to the shape of the portion of the insert (12) that passes through the mounting hole (213).

5. The artificial joint mold according to any one of claims 1 to 4, characterized in that, At least one male mold in the male mold assembly is a first male mold (23), and the pressure head at its bottom is a first pressure head (232). The bottom surface of the first pressure head (232) has a relief groove (234). The first pressure head (232) is used to extend into the recess (211) before the second raw material layer (112) is placed into the recess (211) and press down on the top surface of the first raw material layer (111) in the recess (211). The relief groove (234) can be sleeved on the outer side of the top of the plug (22).

6. The artificial joint mold according to claim 5, characterized in that, The depth of the relief groove (234) is greater than the maximum depth to which the first pressure head (232) extends into the recess (211) during the molding process.

7. The artificial joint mold according to any one of claims 1 to 4, characterized in that, At least one of the male molds in the male mold assembly is a second male mold (24), and the pressure head at its bottom is a second pressure head (242) for pressing down on the top surface of the second raw material layer (112) in the recess (211); the second pressure head (242) has an arc-shaped surface (244) for forming the friction surface of the artificial joint.

8. The artificial joint mold according to claim 7, characterized in that, The roughness of the friction surface is no greater than Ra0.

5.

9. A method for preparing an artificial joint, characterized in that, The artificial joint mold according to any one of claims 1 to 8 comprises: The plunger (22) is fitted downward into the mounting hole (213); Raw material is poured into the recess (211) to form a first raw material layer (111); The first raw material layer (111) is molded to form a first blank (114), and an inner hole (113) is formed on the first blank (114) at the position of the plug (22). Remove the plunger (22) and insert the insert (12) into the inner hole (113) and the mounting hole (213) in sequence, with the overlapping edge (123) of the insert (12) resting on the first blank (114); Then, raw materials are poured into the recess (211) to form a second raw material layer (112), and the first blank (114) and the second raw material layer (112) are molded into an inner liner element (11) that fits into the insert (12).

10. The method for preparing an artificial joint according to claim 9, characterized in that, The step of pouring raw material into the recess (211) to form a first raw material layer (111) includes: Pour the raw material into the recess (211) until it is flush with the top surface of the plug (22).

11. The method for preparing an artificial joint according to claim 9, characterized in that, The molding of the first raw material layer (111) to form the first blank (114) includes: The first male mold (23) is assembled into the recess (211) and the first raw material layer (111) is cold-pressed to form the first blank (114). In the cold pressing process, the pressure range is 2-20 MPa, and the holding time ranges from 5-30 min.

12. The method for preparing an artificial joint according to claim 9, characterized in that, The process of molding the first blank (114) and the second raw material layer (112) into an inner liner element (11) that fits into the insert (12) includes: The second male mold (24) is assembled into the recess (211), and the first blank (114) and the second raw material layer (112) are hot-pressed to form an inner lining element (11) that fits into the insert (12). In the hot pressing process, the temperature range is 110-250℃, the pressure range is 0.5-20 MPa, and the holding time ranges from 30-300 min.

13. The method for preparing an artificial joint according to claim 9, characterized in that, The raw materials are in the form of powder or granules.

14. An artificial joint, characterized in that, The artificial joint is made by the method of any one of claims 9-13; wherein the artificial joint includes an inner liner element (11) and an insert (12) embedded in the inner liner element (11), a portion of the structure of the insert (12) protruding from the inner liner element (11), and the inner liner element (11) is made of a polymer material.

15. The artificial joint according to claim 14, characterized in that, The polymer material is ultra-high molecular weight polyethylene with or without crosslinking agent, or high molecular weight polyethylene, or PEEK, or ordinary polyethylene.

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