Fabrication of fiber-reinforced implants

Abstract

A method for manufacturing a fiber-reinforced implant structure is disclosed. A fiber-reinforced rigid insert is provided, comprising continuous fibers impregnated with a first thermoplastic polymer. A molding cycle is performed by overmolding. The insert is placed into a cavity; and a second thermoplastic polymer in molten form is injection-molded or compression-molded into the cavity. Thus, the insert is at least partially covered by the second thermoplastic polymer. The second thermoplastic polymer injected or compressed into the cavity is cooled, thereby obtaining a molded fiber-reinforced implant structure comprising the at least partially covered insert. During the injection molding or compression molding and during the cooling, the insert is in a predetermined position within the cavity. The first thermoplastic polymer and the second thermoplastic polymer may be the same or different. An implant structure and an implant comprising the implant structure are also disclosed.

Description

Technical Field

[0001] This invention relates to a fiber-reinforced implant structure and a method for manufacturing the fiber-reinforced implant structure. The invention also relates to an implant comprising the fiber-reinforced implant structure. Background Technology

[0002] Fiber-reinforced polymers are composite materials made from fiber-reinforced polymer matrices, commonly used in the aerospace, automotive, marine, and construction industries. The potential applications of fiber-reinforced composite technology in the manufacture of medical implants may address some of the challenges currently faced by metals, such as corrosion, imaging interference (e.g., magnetic resonance imaging, MRI), and the mechanical property mismatch between bone and implant materials. Compared to polymer implants, fiber-reinforced composite implants exhibit superior mechanical properties, improved biocompatibility, and more. The potential of fiber-reinforced composites in implant technology is based on the fact that these materials exhibit superior mechanical properties compared to ordinary polymers and / or particulate-filled composites. Typically, improved mechanical properties are the most important reason for using fiber-reinforced composites.

[0003] Injection molding is a process used to manufacture parts in which molten material (such as thermoplastic and / or thermosetting polymers) is injected into a mold. The raw material is fed into a heated barrel, mixed using a helical screw, and forced into the cavity by injection. The material then cools and hardens the construction of the cavity. High-pressure injection of the raw material into the mold shapes the polymer into the desired form. The series of events during the injection molding of a plastic part can be called an injection molding cycle, which begins when the mold is closed, followed by the injection of polymer into the cavity. Once the cavity is filled, holding pressure is maintained to prevent material shrinkage. Once the part has cooled to the desired temperature, the mold is opened, and the part is ejected. This process then begins the molding cycle to manufacture the next part, and these cycles are repeated until the desired number of products are produced.

[0004] Overmolding is an injection molding process in which molten matrix material is injected into an injection cavity containing individual inserts. The individual inserts are placed in the cavity before the molten matrix material is injected. The result is an overmolded product formed from the inserts and the matrix material. Overmolding can also be used in conjunction with other types of molding processes. Overmolding can also be used, for example, in compression molding, where individual inserts are placed in the cavity before a compression molding cycle. Similar to injection molding, the result of compression molding is an overmolded product formed from the inserts and the matrix material.

[0005] Inserts can include, for example, wire inserts, reinforcing fabrics, stitching threads, etc. One challenge with fabrics and / or other flexible inserts is that they can move and / or undergo uncontrolled shape changes as the polymer melt flows through the mold during melt injection into the cavity. This can jeopardize the desired functionality of the insert. Summary of the Invention

[0006] The following is a brief summary of the features disclosed herein to provide a basic understanding of some exemplary aspects of the invention. This summary is not a broad overview of the invention. The invention is not intended to identify key / critical elements or to define its scope. Its sole purpose is to present some of the concepts disclosed herein in a simplified form as a prelude to a more detailed description.

[0007] According to one aspect, the subject matter of the independent claim is provided. Embodiments are defined in the dependent claims.

[0008] One or more examples of embodiments are set forth in more detail in the following description. Other features will become clear from the specification and from the claims. Attached Figure Description

[0009] In the following, the invention will be described in more detail with reference to the accompanying drawings and preferred embodiments, wherein...

[0010] Figure 1a An exemplary mold is illustrated;

[0011] Figure 1b An exemplary rigid insert is shown placed on the core of the cavity;

[0012] Figure 2a The illustration shows an exemplary overmolded product manufactured according to the present invention;

[0013] Figure 2b The illustration shows an overmolded product manufactured using soft / deformable inserts;

[0014] Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6 , Figure 7 and Figure 8 The illustration shows an exemplary overmolded product / implant according to the present invention;

[0015] Figure 9 and Figure 10 The test results of the measurement are shown;

[0016] Figure 11a An exemplary rigid insert placed in a cavity according to the present invention is illustrated;

[0017] Figure 11b The illustration shows an exemplary overmolded product manufactured according to the present invention;

[0018] Figures 12a to 12e The illustration shows the fabrication of the plate-like implant structure. Detailed Implementation

[0019] The following embodiments are exemplary. Although the specification may refer to "a," "an," or "some" embodiments in multiple places, this does not necessarily mean that each such reference is for the same embodiment, or that the described feature is applicable only to a single embodiment. Individual features of different embodiments may also be combined to provide to other embodiments. Furthermore, the words "comprising," "containing," and "including" should be understood not to limit the described embodiments to including only those features already mentioned, but rather that these embodiments may also contain features / structures not specifically mentioned.

[0020] This invention discloses a fiber-reinforced implant structure and a method for producing the fiber-reinforced implant structure. In the method, a formed continuous fiber-reinforced implant or implant structure is produced by overmolding, wherein a continuous fiber-containing insert serves as a reinforcement in the implant or implant structure. The continuous fiber-containing insert is at least partially overmolded from a thermoplastic matrix polymer. The continuous fiber-containing insert is rigid. The rigid fiber-containing insert is inserted into the cavity of an injection molding machine, the mold is then closed, and thermoplastic matrix material is injected into the cavity to perform injection molding via overmolding. After possible shaping and / or curing, the part is allowed to cool to a desired temperature after mold opening and ejection. Such a part can be used (or used for) medical implants and can be manufactured by industrial processes. Alternatively, the rigid fiber-containing insert is inserted into the cavity of a compression molding machine, the mold is then closed, and thermoplastic matrix material is pressed into the cavity to perform compression molding via overmolding. After possible shaping and / or curing, the mold can be cooled to the desired temperature, and the part can be ejected from the mold. This part can be used (or used for) medical implants and can be manufactured through industrial processes.

[0021] Fiber-containing inserts are rigid. This rigidity allows the fiber reinforcement to remain in the desired position during the injection (or compression) molding process (i.e., during the injection (or compression) of the thermoplastic matrix material into the cavity). During injection (or compression) and / or setting / curing, the cavity may be exposed to pressures of several thousand bar. Possible curing stages can be used to heat-treat the molded sample to alter certain properties. These properties include, but are not limited to, increased crystallinity, which enhances certain mechanical properties and can improve thermal stability.

[0022] If soft inserts, such as untreated wound inserts or untreated knitted inserts, are used instead of rigid inserts, holding the inserts in place during the injection molding process will be extremely challenging. If soft / deformable inserts are used as inserts, it will be very difficult to ensure that the fibers are located in the desired place / position within the molded part; see [link to related documentation]. Figure 2b The illustration shows an overmolded component with a soft / deformable insert in the core.

[0023] In one embodiment, the rigid insert can move naturally during the molding process, but the rigidity of the insert allows for adjustment of the fiber reinforcement placement after the molding process. The rigid insert can also be used to adjust the positioning of the reinforcement, such that the insert expands, contracts, and / or otherwise moves with the molded part to the desired location or shape for installation. For example, a thermoplastic polymer material can be injected into the center of the implant structure, where the reinforcement expands to the desired location (on the surface of the implant).

[0024] In one embodiment, the rigid insert comprises continuous fibers bonded together using a thermoplastic polymer to form a rigid structure. Here, continuous fiber means that at least a portion of the fibers in the insert are as long as the shortest dimension, thinnest wall thickness, or any other dimension easily determined by the geometry of the final product being manufactured. Preferably, the continuous fiber is at least as long as the longest principal dimension, diameter, or other dimension of the article being manufactured.

[0025] Fiber length represents the continuity of the fiber. Fibers may break during this process. Continuous fibers are equal to or longer than the minimum wall thickness of the implant. At least some fibers in the implant are at least as long as the shortest dimension physically measured from the implant geometry. If the implant is cylindrical, this means the diameter of the cylinder. In the case of a tubular implant, this means the wall thickness of the tube. Therefore, the fiber length is continuous in the physical dimensions of the implant. In practice, an implant may contain fibers, where at least some fibers are preferably longer than the longest principal dimension of the implant. In the case of a cylindrical implant, this means at least some fibers are longer than the diameter of the cylinder. In the case of a tubular implant, this means at least some fibers are longer than the wall thickness of the tube. In the example below, a "tubular screw" is used, which contains fibers much longer than the length of the screw. Therefore, this fiber is also much longer than the wall thickness. As mentioned above, continuous fibers refer to fibers whose length corresponds to the shortest wall thickness or shortest principal dimension of the implant (or molded component).

[0026] Inserts containing rigid, continuous fibers can be made from thermoplastic polymer-impregnated fiber prepregs, such as impregnated tapes, strips, or threads. The fiber prepreg can include any fiber capable of being used as a fiber reinforcement, such as polymer fibers, glass fibers, carbon fibers, aramid fibers, etc. The fiber reinforcement can also be a mixed fiber reinforcement comprising multiple different reinforcing fibers. The mixed fiber reinforcement can further comprise reinforcing fibers within individual fibers and bonded thermoplastic polymer fibers. If such a mixed fiber reinforcement is used, the resulting structure is treated by molding to melt the thermoplastic polymer fibers to bond the reinforcing fibers and form a rigid structure before using the formed structure as an insert.

[0027] The thermoplastic matrix material used for injection (or compression) molding via overmolding can be a pure (undoped) thermoplastic homopolymer, copolymer, ternary polymer, depolymerized blend, or a mixture of polymer and additives, such as a mixture of polymer and calcium phosphate (e.g., β-tricalcium phosphate (β-TCP)), a mixture of polymer and glass particles, or a mixture of polymer and chopped glass fiber, chopped carbon fiber and / or any feasible mineral additives.

[0028] Prior to the molding process, an insert containing continuous fiber reinforcement is prepared via a separate process. The process for manufacturing the continuous fiber insert can be a one-step process or may include several intermediate steps. During the manufacturing of the continuous fiber insert, a preform (prepreg) comprising the fiber reinforcement and a thermoplastic polymer impregnated material binding the fibers is further processed into the desired shape, which can then be used as an insert in the final overmolding process. The rigid state of the continuous fiber insert is achieved by melting or dissolving the polymer impregnated material binding the fiber reinforcement, thereby bonding different layers or adjacent structural portions of the polymer impregnated material together to strengthen the fiber insert structure.

[0029] For example, filament winding technology or automated fiber / tape placement technology can be used to manufacture inserts containing continuous fibers, thereby providing the desired fiber orientation of the insert and producing multilayer fiber structures, each layer having a precise desired orientation.

[0030] Methods for manufacturing inserts containing continuous fibers may also include any manufacturing method used in the textile industry (such as braiding, knitting, weaving, etc.). However, if conventional manufacturing processes from textile technology are used, the resulting structure is generally not rigid, and therefore the resulting fiber-reinforced structure must be hardened in a further process step, such as by treating the preform with heat and / or solvents, to achieve a rigid structure for the insert.

[0031] The process for manufacturing inserts containing continuous fibers can also include 3D printing. However, in this case, the entire structure of the insert is not produced by 3D printing.

[0032] The process for manufacturing inserts containing rigid continuous fibers can also be a combination of the different manufacturing methods mentioned above, including filament winding, automated tape placement, 3D printing, solvent casting, vacuum bagging, extrusion, injection molding, compression molding, and textile industrial processes (such as braiding, knitting, weaving).

[0033] The geometry of the component is achieved during the overmolding process. In overmolding, a continuous fiber-reinforced insert is placed in a cavity, the mold is then closed, and the cavity is filled with a thermoplastic material to provide the final geometry of the fiber-reinforced component. The continuous fiber insert can be positioned in the core of the final product (as in Example 1 below), inside the final product, or on the surface of the final product (as in Example 2 below). The fiber reinforcement can also be positioned on one or more surfaces of the final product. Aside from the geometric constraints imposed by the molding process, the final product has no geometric constraints on its shape. Therefore, the component shape or implant shape can be any possible shape that can be molded, such as a plate, screw, nail, etc.

[0034] Figure 2a , Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6 , Figure 7 and Figure 8 The illustration depicts an exemplary overmolded component / implant according to the present invention. (See illustration from...) Figure 2a , Figure 3a , Figure 3b , Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6 , Figure 7 and Figure 8 Therefore, the final product can be any shape that can be obtained by using this invention. The continuous fiber reinforced insert can be positioned in the core, surface, interior, one end or multiple ends of the product, or the position of the continuous fiber-containing insert can be any combination of the above positions.

[0035] This invention enables the fabrication of medical implants that address certain challenges associated with metals, such as corrosion, imaging interference (e.g., MRI), and the mechanical property mismatch between bone and implant materials. Fiber-reinforced composite implants exhibit superior mechanical properties, improved cytotoxicity, and improved biocompatibility compared to polymer implants or other composite materials. The potential of fiber-reinforced composites in implant technology is based on the fact that these materials exhibit superior mechanical properties compared to undoped polymers and / or particulate-filled composites. Generally, improved mechanical properties are the most important reason for using composite materials. This invention does not set any limitations on fiber orientation, as fiber inserts can be fabricated using manufacturing techniques that combine multiple manufacturing processes.

[0036] Therefore, embodiments disclose a structure and a method for manufacturing a fiber-reinforced implant structure. In this method, a fiber-reinforced rigid insert is provided. The insert comprises continuous fibers impregnated with at least one first thermoplastic polymer. A molding cycle is performed by overmolding using a pre-manufactured fiber insert, the molding cycle comprising: placing the fiber-reinforced rigid insert in a cavity; injection molding or compression molding at least one second thermoplastic polymer in molten form into the cavity such that the fiber-reinforced rigid insert placed in the cavity is at least partially covered by at least one second thermoplastic polymer; and subjecting the at least one second thermoplastic polymer injected or compressed into the cavity to setting and / or curing, thereby obtaining a molded fiber-reinforced implant structure comprising a fiber-reinforced rigid insert at least partially covered by at least one second thermoplastic polymer. The fiber-reinforced rigid insert remains in the cavity during injection molding / compression molding and during setting / curing or cooling. The at least one first thermoplastic polymer and the at least one second thermoplastic polymer may be the same or different.

[0037] In one embodiment, a fiber-reinforced rigid insert is placed into the cavity prior to injection molding or compression molding.

[0038] In one embodiment, after the fiber-reinforced rigid insert is placed into the cavity, the cavity is sealed and filled with at least one second thermoplastic polymer.

[0039] In one embodiment, during injection molding or compression molding, the cavity is exposed to a pressure of 1 bar to 2500 bar.

[0040] In one embodiment, during the back pressure phase, the cavity is exposed to pressures ranging from 1 bar to 2500 bar.

[0041] In one embodiment, during shaping and / or curing, the cavity is exposed to pressures ranging from 1 bar to 2500 bar.

[0042] In one embodiment, at least one second thermoplastic polymer comprises a pure (undoped) thermoplastic polymer or a polymer blend, and / or at least one second thermoplastic polymer further comprises additives.

[0043] In one embodiment, at least one second thermoplastic polymer comprises a homopolymer, a copolymer, and / or a terpolymer.

[0044] In one embodiment, the additive is at least one of the following: calcium phosphate (such as β-tricalcium phosphate (β-TCP)), glass particles, chopped glass fibers, chopped carbon fibers, any feasible mineral additives, plasticizers, and nucleating agents. The additive can be any additive capable of altering the properties of the polymer.

[0045] In one embodiment, the fiber-reinforced insert comprises polymer fibers, glass fibers, carbon fibers, and / or aramid fibers impregnated with the at least one first thermoplastic polymer.

[0046] In one embodiment, the fiber-reinforced insert is prepared by processing a preform comprising fibers impregnated with the at least one first thermoplastic polymer into a desired shape, and melting and / or dissolving the at least one first thermoplastic polymer, wherein continuous layers and / or adjacent structural portions of the at least one first thermoplastic polymer material are bonded to each other, thereby providing a fiber-reinforced rigid insert.

[0047] In one embodiment, the fiber-reinforced insert is prepared by using filament winding and / or automated tape / fiber placement.

[0048] In one embodiment, a fiber-reinforced insert is prepared by using braiding, knitting, and / or knitting, followed by heat treatment and / or solvent treatment, thereby providing a fiber-reinforced rigid insert.

[0049] In one embodiment, fiber-reinforced inserts are partially fabricated using 3D printing.

[0050] In one embodiment, fiber-reinforced inserts can be fabricated using a combined manufacturing approach, where a free fiber orientation design created by 3D printing is combined with a consistent fiber reinforcement created using another technique. As a non-limiting example of a combined manufacturing technique, the core of a rigid fiber insert can be formed from a filament-wound continuous fiber reinforcement tube with different fiber orientations (e.g., ...-45° / 45° / -45° / 45°... or any other possible fiber orientation obtained by filament winding) between stacked tube layers and 3D-printed continuous filaments, which are 3D-printed on top of the filament-wound tube, in the core, or in the desired fiber path in the middle / between. The resulting hybrid insert is rigid in both the core (rigid filament-wound tube) and the structure 3D-printed on top of the core. 3D fiber printing allows for completely free alignment of the fiber reinforcements without being limited by conventional manufacturing methods such as filament winding.

[0051] In one embodiment, the fiber is at least as long as the shortest dimension, thinnest wall thickness, or any other dimension determined by the geometry of the formed fiber-reinforced implant or implant structure. Preferably, the fiber is at least as long as the longest principal dimension, diameter, or other dimension of the formed fiber-reinforced implant or implant structure.

[0052] Another embodiment discloses a molded fiber-reinforced implant or implant structure including a fiber-reinforced rigid insert. The fiber-reinforced rigid insert includes continuous fibers impregnated with at least one first thermoplastic polymer and at least one second thermoplastic polymer, such that the fiber-reinforced rigid insert is at least partially covered in the molded fiber-reinforced implant or implant structure by overmolding with at least one second thermoplastic polymer. The at least one first thermoplastic polymer and the at least one second thermoplastic polymer may be the same or different.

[0053] In one embodiment, the implant or implant structure has the shape of a plate, screw, or nail. Figures 12a to 12e The illustration shows the fabrication of the plate-like implant structure.

[0054] In one embodiment, the implant or implant structure may be hollow or solid.

[0055] In one embodiment, the implant or implant structure may be perforated (see...). Figure 8 ).

[0056] In one embodiment, the insert may be hollow or solid.

[0057] In one embodiment, the insert may be perforated (see...). Figure 8 ).

[0058] In one embodiment, the implant or implant structure includes polymer fibers, glass fibers, carbon fibers and / or aramid fibers.

[0059] In one embodiment, the insert comprises multiple layers of continuous fibers, each layer being in a selected fiber orientation within the insert.

[0060] In one embodiment, the insert is positioned in the core of the implant or implant structure, inside the implant or implant structure, or at least partially positioned on the surface of the implant or implant structure.

[0061] In one embodiment, the implant or implant structure is produced by the method described above.

[0062] In one embodiment, a medical implant is provided, which includes the implant structure described above.

[0063] Example 1

[0064] Rigid fiber-reinforced inserts are fabricated using filament winding as a manufacturing technique. These inserts consist of preformed tapes of continuous glass fibers and thermoplastic polymer matrices, which are further processed into four-layer and six-layer tubular structures. During filament winding, the preformed tape is heated above the melting point of the bonding thermoplastic polymer. The fiber orientation in the four-layer structure is 45° / -45° / 45° / -45° / …. The preformed rigid insert is then placed into a cavity on top of the core (see…). Figure 1b The thermoplastic matrix material is then injection molded into the fiber-reinforced insert in a cavity, thereby obtaining the fiber-reinforced implant as the final injection-molded component (see...). Figure 2a In Example 1, fiber reinforcement is positioned within the core of the implant. The torsional strength of the manufactured composite is compared to that of the same product design composed of undoped polymer. The results are... Figure 9 Shown in.

[0065] Example 2

[0066] Rigid fiber-reinforced inserts were fabricated using filament winding as a manufacturing technique. A preformed tape comprising continuous glass fibers and a thermoplastic polymer matrix was further processed into a four-layer tubular structure. During filament winding, the preformed tape was heated above the melting point of the bonding thermoplastic polymer. The fiber orientation in the four layers of the structure was 45° / -45° / 45° / -45°. The preformed rigid insert was then placed into a cavity on top of a core pin (see...). Figure 11a The insert is designed such that the injected matrix polymer fills the mold from the core of the implant and from the core of the rigid insert. A thermoplastic matrix material is then injection molded into the cavity, where a fiber-reinforced implant is obtained as the final injection-molded part (see...). Figure 11bThe rigid insert is designed so that the injected material flows into the center of the mold, inside the tube, which forces the tubular insert to expand slightly towards the mold wall. Although the tubular insert used is rigid, the expansion can be controlled because the thermoplastic polymer bonded to the glass fiber layer of the rigid insert melts simultaneously, and the molten matrix polymer is injected into the cavity at a pressure of 1500 bar. Therefore, the rigid insert allows for control of the insert's movement during molding and allows for adjustment of the position of the reinforcing fibers in the final product. In Example 2, the fiber reinforcement is positioned on the surface of the implant. The torsional strength of the manufactured composite is compared with that of the same product design composed of undoped polymer. The results are in Figure 10 Shown in.

[0067] Example 3

[0068] Figures 11a to 11b An exemplary case is shown where a reinforcement is placed in the core, and thermoplastic polymer material is injected into the center of the mold, after which the reinforcement expands towards the surface in a controlled manner, see item 114. This controlled expansion can only be achieved using a rigid reinforcement. If a non-rigid insert is used, the post-molding condition will be similar to... Figure 2b The presentation is similar. In Figure 11b In Figure 114, the molded rigid insert is illustrated, which has a customized position within the implant structure. Figure 11b In Figure 113, the result after molding is illustrated, showing the molded implant with rigid inserts expanding toward the surface of the outer mold. Figure 11b In Figure 115, a molded core or matrix is ​​injected into a mold. Figure 11a In Figure 112, a space is illustrated that allows polymer melt to flow into the interior of the sample, where the pressure generated by the melt flow causes the initially rigid insert to expand toward the mold wall. Figure 11a In the example, item 111 shows a specially shaped core that allows for mold filling from the center of the core.

[0069] Those skilled in the art will clearly see that, with advancements in technology, the concept of this invention can be implemented in various ways. The invention and its embodiments are not limited to the examples described above, but can be varied within the scope of the claims.

Claims

1. A method for manufacturing fiber-reinforced medical implant structures, A fiber-reinforced rigid insert is provided, the fiber-reinforced rigid insert comprising continuous fibers impregnated with at least one first thermoplastic polymer. The molding cycle is performed through overmolding, including The fiber-reinforced rigid insert is placed into the cavity; At least one second thermoplastic polymer in molten form is injection molded or compression molded into the cavity, such that the fiber-reinforced rigid insert placed in the cavity is at least partially covered by the at least one second thermoplastic polymer, and At least one second thermoplastic polymer is injected or compressed into the cavity to obtain a molded fiber-reinforced medical implant structure comprising a fiber-reinforced rigid insert at least partially covered by the at least one second thermoplastic polymer. in, During the injection molding or compression molding process and during the cooling process, the fiber-reinforced rigid insert is positioned at a predetermined location within the cavity. Wherein, the at least one first thermoplastic polymer and the at least one second thermoplastic polymer may be the same or different. The at least one second thermoplastic polymer further comprises an additive, wherein the additive is at least one selected from calcium phosphate, β-tricalcium phosphate (β-TCP), glass particles, and mineral additives.

2. The method as described in claim 1, wherein, The fiber-reinforced rigid insert is placed into the cavity prior to the injection molding or compression molding.

3. The method as described in claim 2, wherein, After the fiber-reinforced rigid insert is placed into the cavity, the cavity is closed and filled with the at least one second thermoplastic polymer.

4. The method of claim 1, wherein, During the injection molding or compression molding process and during the cooling process, the cavity is exposed to pressures ranging from 1 bar to 2500 bar.

5. The method of claim 1, wherein The at least one second thermoplastic polymer includes an undoped thermoplastic polymer or a polymer blend. The at least one second thermoplastic polymer includes homopolymers, copolymers, and / or terpolymers, and / or The at least one second thermoplastic polymer further comprises chopped carbon fibers and / or chopped glass fibers as additives.

6. The method according to any one of claims 1 to 5, wherein, The fiber-reinforced rigid insert comprises polymer fibers, glass fibers, carbon fibers, and / or aramid fibers impregnated with at least one first thermoplastic polymer.

7. The method according to any one of claims 1 to 5, wherein, The fiber-reinforced rigid insert is prepared by the following: The preform is processed into a desired shape, the preform comprising fibers impregnated with the at least one first thermoplastic polymer, and Melting or dissolving the at least one first thermoplastic polymer, wherein continuous layers and / or adjacent structural portions of the at least one first thermoplastic polymer material are bonded to each other, thereby providing the fiber-reinforced rigid insert.

8. The method according to any one of claims 1 to 5, wherein, The fiber-reinforced rigid insert is prepared by using filament winding, automated tape placement, and / or automated fiber placement.

9. The method according to any one of claims 1 to 5, wherein, The fiber-reinforced rigid insert is prepared by using braiding, knitting and / or knitting, followed by heat treatment and / or solvent treatment, thereby providing the fiber-reinforced rigid insert.

10. The method according to any one of claims 1 to 5, wherein, The fiber-reinforced rigid insert is prepared by 3D printing of continuous fibers and / or by other processes for preparing rigid inserts from pre-impregnated materials containing continuous fibers.

11. The method according to any one of claims 1 to 5, wherein, The continuous fiber is at least as long as the shortest dimension, thinnest wall thickness, or any other dimension determined by the geometry of the formed fiber-reinforced medical implant structure.

12. A molded fiber-reinforced medical implant structure, comprising: Fiber-reinforced rigid inserts, wherein, The fiber-reinforced rigid insert comprises continuous fibers impregnated with at least one first thermoplastic polymer, and At least one second thermoplastic polymer, such that the fiber-reinforced rigid insert is at least partially covered by the at least one second thermoplastic polymer in the molded fiber-reinforced medical implant structure by overmolding. Wherein, the at least one first thermoplastic polymer and the at least one second thermoplastic polymer may be the same or different. The at least one second thermoplastic polymer further comprises an additive, wherein the additive is at least one selected from calcium phosphate, β-tricalcium phosphate (β-TCP), glass particles, and mineral additives.

13. The medical implant structure as described in claim 12, wherein, It has the shape of a plate, screw, or nail.

14. The medical implant structure as described in claim 12, wherein... The at least one second thermoplastic polymer includes an undoped thermoplastic polymer or a polymer blend. The at least one second thermoplastic polymer includes homopolymers, copolymers, and / or terpolymers, and / or The at least one second thermoplastic polymer further comprises chopped carbon fibers and / or chopped glass fibers as additives.

15. The medical implant structure according to any one of claims 12 to 14, wherein, It includes polymer fibers, glass fibers, carbon fibers and / or aramid fibers impregnated with at least one first thermoplastic polymer.

16. The medical implant structure according to any one of claims 12 to 14, wherein, The fiber-reinforced rigid insert comprises multiple layers of continuous fibers, each layer being in a selected fiber orientation within the fiber-reinforced rigid insert.

17. The medical implant structure according to any one of claims 12 to 14, wherein, The fiber-reinforced rigid insert comprises multiple layers of continuous fibers, each layer being in a selected fiber orientation within the fiber-reinforced rigid insert, and a 3D-printed structure is 3D-printed on top of the layered fiber-reinforced rigid insert.

18. The medical implant structure according to any one of claims 12 to 14, wherein, The fiber-reinforced rigid insert comprises multiple layers of continuous fibers, each layer being in a selected fiber orientation within the fiber-reinforced rigid insert, and a 3D-printed structure is 3D-printed on the core of the layered fiber-reinforced rigid insert.

19. The medical implant structure according to any one of claims 12 to 14, wherein, The continuous fiber is at least as long as the shortest dimension, thinnest wall thickness, or any other dimension determined by the geometry of the formed fiber-reinforced medical implant structure.

20. The medical implant structure according to any one of claims 12 to 14, wherein, The fiber-reinforced rigid insert is positioned in the core of the medical implant structure, inside the medical implant structure, or at least partially on the surface of the medical implant structure.

21. The medical implant structure according to any one of claims 12 to 14, wherein, It is produced by the method according to any one of claims 1 to 11.

22. A medical implant comprising the medical implant structure as described in any one of claims 12 to 21.

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