Metal reinforced polymer femoral component for orthopaedic knee prosthesis and associated method of manufacture

Abstract

An orthopaedic knee joint prosthesis (10) includes a femoral component having a metal base (84) and a polymeric joint layer molded to the metal base. A method of making a metal reinforced femoral component for an orthopaedic knee prosthesis is also disclosed.

Description

Technical Field

[0001] This disclosure relates generally to an implantable orthopedic knee prosthesis, and more specifically to an implantable femoral component of an orthopedic knee prosthesis. Background Technology

[0002] During a patient's life, joint replacement procedures may be necessary due to factors such as disease or trauma. Therefore, arthroplasty has become a well-known surgical procedure by which a diseased and / or damaged natural joint is replaced with a prosthetic joint. For example, in the total knee arthroplasty procedure, a patient's natural knee joint is partially or completely replaced with a prosthetic knee joint or knee prosthesis. A typical knee prosthesis includes a tibial support, a femoral component, and a polymer insert or support positioned between the tibial support and the femoral component. In this case, the femoral component is fixed to the surgically prepared distal end of the patient's femur, while the tibial support is fixed to the surgically prepared proximal end of the patient's tibia. The polymer support is coupled to the tibial support and thus provides a support surface on which the femoral component hinges during knee extension and flexion.

[0003] Conventional femoral components are embodied as monolithic metal components constructed from implantable biocompatible metals. Examples of such metals include cobalt (including cobalt alloys such as cobalt-chromium alloys), titanium (including titanium alloys such as Ti6Al4V alloys), and stainless steel. Summary of the Invention

[0004] According to one aspect of this disclosure, an orthopedic knee prosthesis includes a femoral component. The femoral component includes a metal base having a lower base surface curved in a longitudinal bisecting plane. The lower base surface has a plurality of elongated ribs extending downward from the lower base surface. The metal base also has an upper base surface including a posterior fixation surface extending generally in an up / down direction, a distal fixation surface extending generally in an anterior / posterior direction, a posterior inclined fixation surface extending upward and backward from the distal fixation surface in a direction toward the posterior fixation surface, an anterior fixation surface extending generally in an up / down direction, and an anterior inclined fixation surface extending upward and forward from the distal fixation surface in a direction toward the anterior fixation surface. The femoral component also includes a polymer articular layer molded to the lower base surface of the metal base and molded into a plurality of elongated grooves defined by the plurality of ribs. The polymer articular layer has an articular motion surface curved in a longitudinal bisecting plane and configured to hinge with a support surface of a tibial component.

[0005] In the implementation scheme, a porous metal coating is applied to the upper base surface of the metal substrate.

[0006] The porous metal coating can be applied to the entirety of each of the rear fixing surface, distal fixing surface, rear inclined fixing surface, front fixing surface, and front inclined fixing surface of the upper base surface of the metal base.

[0007] In one embodiment, the metal base includes a plurality of lugs extending upward from the distal fixing surface, and a porous metal coating is disposed on the lugs.

[0008] An undercut may be formed at the lower end of each of the plurality of ribs. The lower ends of the plurality of ribs defining the undercut may include a circular surface.

[0009] In one embodiment, multiple ribs extend in the longitudinal bifurcation plane. In another embodiment, multiple ribs extend in the coronal plane.

[0010] In the implementation scheme, multiple ribs are fully embedded in the polymer joint layer.

[0011] In the implementation plan, many of the multiple ribs are hollow.

[0012] The polymeric articular layer of the femoral component can be constructed using polyaryletherketone (PAEK). In other embodiments, the polymeric articular layer of the femoral component is constructed using other biocompatible polymers, copolymers, and / or polymer blends.

[0013] In another aspect, an orthopedic knee prosthesis system includes a tibial component configured for implantation on the proximal end of a patient's tibia and a femoral component configured for implantation on the distal end of a patient's femur. The tibial component includes a concave support surface. The femoral component includes a metal base having a lower base surface curved in a longitudinal plane. A plurality of elongated ribs extend downward from the lower base surface. The metal base also includes an upper base surface having a plurality of bone fixation surfaces. A plurality of lugs extend upward from one of the bone fixation surfaces. The femoral component also includes a porous metal coating disposed on the upper base surface of the metal base and the lugs. A polymer articulation layer is molded onto the lower base surface of the metal base and molded into a plurality of elongated grooves defined by the plurality of ribs. The polymer articulation layer has an articulation surface curved in a longitudinal plane and configured to hinge to the support surface of the tibial component.

[0014] In the implementation, the upper base surface includes a rear fixing surface extending generally in an up / down direction, a distal fixing surface extending generally in a front / back direction, a rear inclined fixing surface extending upward and backward from the distal fixing surface in a direction toward the rear fixing surface, a front fixing surface extending generally in an up / down direction, and a front inclined fixing surface extending upward and forward from the distal fixing surface in a direction toward the front fixing surface.

[0015] The porous metal coating can be applied to the entirety of each of the rear fixing surface, distal fixing surface, rear inclined fixing surface, front fixing surface, and front inclined fixing surface of the upper base surface of the metal base.

[0016] An undercut may be formed at the lower end of each of the plurality of ribs. The lower ends of the plurality of ribs defining the undercut may include a circular surface.

[0017] In one embodiment, multiple ribs extend in the longitudinal bifurcation plane. In another embodiment, multiple ribs extend in the coronal plane.

[0018] In the implementation scheme, multiple ribs are fully embedded in the polymer joint layer.

[0019] In the implementation plan, many of the multiple ribs are hollow.

[0020] The polymeric articular layer of the femoral component can be constructed using polyaryletherketone (PAEK). In other embodiments, the polymeric articular layer of the femoral component is constructed using other biocompatible polymers, copolymers, and / or polymer blends.

[0021] According to another aspect, a method of fabricating a femoral component of an orthopedic knee prosthesis includes applying a porous metal coating to a metal base. The metal base has an upper base surface including a plurality of bone fixation surfaces and a plurality of lugs. A polymer articulation layer is molded onto a lower base surface of the metal base that is curved in a longitudinal bisecting plane, such that a plurality of elongated ribs extending downward from the lower base surface are embedded in the polymer articulation layer, and the outer surface of the polymer articulation layer forms an articulation motion surface that is curved in the longitudinal bisecting plane and configured to hinge with a support surface of the tibial component.

[0022] By 3D printing a porous metal coating and a metal base as a single metal part, the porous metal coating can be applied to the upper base surface and numerous lugs of the metal base.

[0023] In one embodiment, an undercut is formed at the lower end of each of the plurality of ribs, and a polymer articulation layer is molded onto the lower base surface of the metal base such that the polymer articulation layer is molded into the undercut of each of the plurality of ribs. Attached Figure Description

[0024] The specific implementation method refers to the following figures, in which:

[0025] Figure 1 This is an exploded perspective view of an orthopedic knee prosthesis, which includes a metal-reinforced polymer femoral component, a tibial support, and a tibial brace.

[0026] Figure 2 It is along Figure 1Line 2-2 is intercepted as observed in the direction of the arrow. Figure 1 Cross-sectional views of the metal-reinforced polymer femoral component and tibial support;

[0027] Figure 3 yes Figure 1 A perspective view of the metal-reinforced polymer femoral component of an orthopedic knee prosthesis;

[0028] Figure 4 and Figure 5 yes Figure 3 Perspective view of the metal base of the metal-reinforced polymer femoral component;

[0029] Figure 6 yes Figure 4 and Figure 5 The lower front view of the metal base; and

[0030] Figure 7 It is along Figure 3 The enlarged cross-sectional view taken by line 7-7, as observed in the direction of the arrow, shows that, for clarity, [the view is shown in the image]. Figure 7 The porous metal coating is not shown in the cross-section. Detailed Implementation

[0031] While the concepts of this disclosure are readily available in various modifications and alternatives, specific exemplary embodiments thereof have been shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that this disclosure is not intended to limit the concepts to the specific forms disclosed, but rather, the object of the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

[0032] Throughout this specification, when referring to orthopedic implants or prostheses and the surgical instruments described herein, as well as the natural anatomy of a patient, terms indicating anatomical reference, such as anterior, posterior, medial, lateral, superior, inferior, etc., may be used. These terms have well-known meanings in anatomical studies and orthopedic surgery. Unless otherwise stated, these anatomical reference terms used in the written details and claims are intended to be consistent with their well-known meanings.

[0033] Now for reference Figure 1 and Figure 2 An orthopedic knee prosthesis 10 is shown, comprising a metal-reinforced polymer femoral component 12, a tibial support 14, and a tibial support 16. The femoral component 12 is configured to hinge to the tibial support 14, which is configured to attach to the tibial support 16. Figure 1In an exemplary embodiment, the tibial support 14 is embodied as a rotatable or movable tibial support and is therefore rotatable relative to the tibial support 16. However, in other embodiments, the tibial support 14 may be embodied as a fixed tibial support (not shown) whose rotation relative to the tibial support 16 is restricted.

[0034] The tibial support 16 is configured to be fixed to the proximal end of a surgically prepared tibia (not shown) in a patient. The tibial support 16 includes a platform 18 having an upper surface 20 and an opposing lower surface 22. The tibial support 16 also includes a rod 24 extending downward from the lower surface 22 of the platform 18. An orifice 26 is defined in the upper surface 20 of the platform 18 and extends downward into the rod 24. The orifice 26 is formed to receive a complementary rod 36 of the tibial support 14, as discussed in more detail below.

[0035] The lower surface 22 of platform 18 and rod 24 define the bone-jointing surface 28 of tibial support 16. (As...) Figure 1 As can be seen, the bone-jointing surface 28 has a porous metallic coating 32 disposed thereon. It should be understood that the porous metallic coating 32 can be a separately applied coating, such as those commercially available from DePuy Synthes of Warsaw, Indiana. or Porous coating. Alternatively, a porous metal coating 32 is applied to the metal body 34 of the tibia support 16 by additive manufacturing simultaneously with the metal body 34 of the support, so as to form a common integral component of the two metal structures.

[0036] As described above, the tibial support 14 is configured to engage with the tibial support 16. The tibial support 14 includes a platform 30 having an upper support surface and a lower support surface. In an exemplary embodiment where the tibial support 14 is embodied as a rotatable or movable tibial support, the support 14 includes a rod 36 extending downward from the lower surface of the platform 30. When the tibial support 14 is engaged with the tibial support 16, the rod 36 is received in an aperture 26 of the tibial support 16. In use, the tibial support 14 is configured to rotate relative to the tibial support 16 about an axis defined by the rod 36. In an embodiment where the tibial support 14 is embodied as a fixed tibial support, the support 14 may or may not include the rod 36 and / or may include other means or features to secure the tibial support 14 to the tibial support 16 in a non-rotational configuration. The upper support surface of the tibial support 14 includes an inner support surface 42 and an outer support surface 44. The inner support surface 42 and the outer support surface 44 are configured to receive or otherwise contact the corresponding medial condyle 52 and lateral condyle 54 of the femoral component 12. Therefore, each of the support surfaces 42, 44 has a concave profile.

[0037] refer to Figure 2 The femoral component 12 is configured to attach to a surgically prepared surface (not shown) at the distal end of the patient's femur. Figure 1 and Figure 2 The femoral component 12 shown is a posterior cruciate knee prosthesis, and the tibial support 14 is embodied as a posterior cruciate tibial support 14. However, in other embodiments, the orthopedic knee prosthesis 10 may be embodied as a posterior cruciate sacrificial knee prosthesis (not shown).

[0038] As described above, the femoral component 12 includes a pair of medial condyles 52 and lateral condyles 54. The condyles 52, 54 are spaced apart to define a condylar notch 56 between the two condyles. In use, the condyles 52, 54 replace the natural condyles of the patient's femur. Each condyle 52, 54 of the femoral component 12 includes a lateral articular surface 50 that is convexly curved in the bisecting plane and configured to hinge to a corresponding support surface 42, 44 of the tibial support 14.

[0039] Opposite to the articular surface 50, the femoral component 12 includes a bone-jointing surface 62. The bone-jointing surface 62 contacts the surgically prepared distal femur of the patient. The bone-jointing surface 62 includes a plurality of surfaces that mate with a flat surface surgically cut into the distal femur of the patient. For example, as... Figure 2 As shown, a pair of posterior fixing surfaces 64 are opposite to the posterior surfaces of condyles 52 and 54, and one of the posterior fixing surfaces 64 is an inner fixing surface, while the other is an outer fixing surface. Figure 1 and Figure 2 As can be seen, the posterior fixation surface 64 extends generally in the up / down direction. A pair of distal fixation surfaces 66 (one positioned medially and the other laterally) are opposite to the distal surfaces of condyles 52 and 54 and extend upward generally in the anterior / posterior direction. A pair of posterior slope fixation surfaces 68 (one positioned medially and the other laterally) are opposite to the posterior slope surfaces of condyles 52 and 54. The medial and lateral posterior slope fixation surfaces 68 extend upward and backward from their respective medial and lateral distal fixation surfaces 66 in a direction toward their respective posterior fixation surfaces 64. The medial and lateral anterior slope fixation surfaces 70 are opposite to the anterior slope surfaces of condyles 52 and 54, respectively, and extend upward and forward away from their respective distal fixation surfaces 66 in a direction toward the anterior fixation surface 72. The anterior fixation surface 72 is opposite to the anterior condylar surface and, like the posterior fixation surface 64, extends upward generally in the up / down direction.

[0040] The bone engagement surface 62 of the femoral component 12 may also include the outer surface of a pair of lugs 74 extending upward from the distal fixation surface 66. The lugs 74 are configured to be received in holes formed in the surgically prepared distal femur of the patient during installation of the femoral component 12.

[0041] The femoral component 12 described herein is embodied as a metal-reinforced polymer component. Therefore, the femoral component 12 includes a polymer articulation layer 82 molded onto a metal base 84 to produce a single-piece (i.e., non-modular) final product. Articular surfaces 50 of the femoral component 12 are formed in the polymer articulation layer 82, thereby defining polymer articulation surfaces configured to hinge to the support surfaces 42, 44 of the tibial support 14.

[0042] The polymeric joint layer 82 of the femoral component 12 is embodied as a monolithic polymeric body constructed of a material that allows for smooth joint movement between the femoral component 12 and the tibial support 14 (which is typically constructed of a biocompatible polymer, such as polyethylene, including ultra-high molecular weight polyethylene (UHMWPE)). Polymers or blends of polymers are preferably used to construct the polymeric joint layer 82. As used herein, the term "polymer" is intended to refer to any polymeric material that can be implanted into a patient. Specific examples of polymers that can be used to construct the femoral component 12 are polyaryletherketone (PAEK), polysulfone, polyimide, and polyacetal families. The term "polyaryletherketone" as defined herein includes polyetheretherketone (PEEK), polyetherketone, and polyetherketone etherketone ketone, or any other type of polyaryletherketone used to construct prosthetic implants, including PEEK blends such as PEEK-polyetherimide and PEEK-polyphenylsulfone blends.

[0043] It should be understood that, as used herein, the term "layer" is not intended to be limited to a certain "thickness" of material located near another material of similar size, but rather to encompass a variety of structures, configurations, and constructions of material. For example, the term "layer" can include portions, regions, or other structures of material located near another portion, region, or structure of a different material.

[0044] Now for reference Figures 4 to 7 The metal base 84 is shown in more detail. (See example...) Figure 4 In China (and in Figure 2 In the cross-section (best visible), the metal base 84 of the femoral component 12 includes an upper base surface 86 and an opposing lower base surface 88, the upper base surface including the bone-jointing surface 62 of the component, the polymer articular layer 82 being molded onto the lower base surface. Figures 2 to 4 As can be seen, the rear fixing surface 64, the distal fixing surface 66, the rear inclined fixing surface 68, the front inclined fixing surface 70, and the front fixing surface 72 are formed in the upper base surface 86.

[0045] like Figure 2 and 4As can be seen, the lower base surface 88 curves in the longitudinal bisecting plane and extends substantially parallel to the articular surface 50 of the femoral component. A plurality of elongated ribs 90 extend downward from the lower base surface 88. Like the lower base surface 88, the elongated ribs 90 extend in the longitudinal bisecting plane. An undercut 94 is formed in the lower end 92 of each of the plurality of ribs 90. Specifically, the lower end 92 of each of the ribs 90 is wider than the opposite end of the rib 90 (i.e., the end of the rib 90 that is attached to the lower base surface 88). Figure 7 As can be seen, rib 90 extends from its lower end 92 along a convex surface 96, which transitions to a concave surface 98 before transitioning to the lower base surface 88, thereby creating an undercut 94. It should be understood that although the undercut 94 is shown as a blended radius undercut 40 (i.e., the surface defining the undercut is circular), other configurations are also conceivable, including, for example, a more square undercut in the design (e.g., rib 90 defining an orthogonal transition rather than a circular transition).

[0046] like Figure 7 As can be seen, the surface of the rib 90 defining the undercut 94 forms a combined surface that is away from the lower base surface 88 of the metal base 84 to which the polymer articulation layer 82 is molded. In this way, the undercut 94 resists pull-out of the polymer articulation layer 82 from the metal base 84.

[0047] It should be understood that although rib 90 is described herein as extending in the longitudinal bifurcation plane, other configurations of rib 90 may be used to suit the needs of a given design of femoral component 12. For example, rib 90 may be arranged to extend in the coronal plane. As another example, rib 90 may be arranged to extend in both the longitudinal bifurcation plane and the coronal plane.

[0048] It should also be understood that the number and geometry of the ribs 90 (e.g., length, width, cross-sectional shape, etc.) can be varied to suit the needs of a given design of the femoral component 12 and / or to impart the desired characteristics to the given design of the femoral component 12. For example, the stiffness of the metal base 84 can be controlled based on the number and cross-sectional shape of the ribs 90. Furthermore, the ribs 90 can be configured as hollow structures (e.g., by using 3D printing). Doing so creates an outer rib geometry that can be used to mold the polymer joint layer 82 to the metal base 84, while also allowing control of the overall stiffness of the femoral component 12 by varying the wall thickness of the hollow ribs. In such an embodiment, the wall thickness can be uniform across the entire cross-section of the rib 90, or thicker in some areas (e.g., the lower end 92 of the rib 90) and thinner in others, based on the structural stiffness required in a given design of the femoral component 12.

[0049] The femoral component 12 is embodied as a non-adhesive component, i.e., the femoral component 12 is designed to be installed on the surgically prepared distal end of the patient's femur without the use of bone adhesive. Therefore, the bone-jointing surface 62 of the femoral component has a porous metallic coating 32 disposed thereon. Similar to the tibial support 16, the porous metallic coating 32 disposed on the femoral component 12 can be a separately applied coating (e.g., or (Porous coating). However, in the exemplary embodiment described herein, the porous metal coating 32 is applied to the metal base 84 via additive manufacturing performed simultaneously with the metal base 84, thereby forming a common integral component of the two metal structures. For example, Porous coatings can be additively manufactured simultaneously with a metal substrate to create a common integral component.

[0050] In one example, the porous metal coating 32 may be made of porous material 80, as described in U.S. Patent Application Serial No. 16 / 365,557, filed March 26, 2019 and assigned to the same assignee as this disclosure, the disclosure of which is incorporated herein by reference as if shown in its entirety herein. By way of example, additive manufacturing processes may include powder bed fusion printing (such as melting and sintering), cold spray 3D printing, filament-feed 3D printing, fused deposition modeling (FDM) 3D printing, extrusion 3D printing, liquid metal 3D printing, stereolithography 3D printing, binder jetting 3D printing, material jetting 3D printing, etc.

[0051] In one example, refer to Figure 7 The porous material 80 of the porous metal coating 32 can be defined by a porous three-dimensional structure, which may include a plurality of connected cells. Each cell may define a cell structure including a plurality of lattice pillars defining an outer geometry and a plurality of internal pillars defining a plurality of internal geometries disposed within the outer geometry. In one example, the outer geometry may be a rhombic dodecahedron and the internal geometry may be a rhombic triangular hexahedron. It should be understood that such geometries can be varied to suit the needs of a given design. Furthermore, it should be understood that the cells constituting the porous metal coating 32 may also have any suitable alternative geometry to suit the needs of a given design.

[0052] The porous material 80 is formed from metal powder. In illustrative terms, the metal powder may include, but is not limited to, titanium, titanium alloys, stainless steel, cobalt-chromium alloys, tantalum, or niobium powder. The porous metal coating 32 has a porosity suitable for promoting bone inward growth into the femoral component 12 when the upper base surface 86 of the metal base 84 and the lug 74 are implanted into the surgically prepared posterior surface of the patient's kneecap.

[0053] In the exemplary embodiments described herein, a porous metal coating 32 is directly additively manufactured onto the upper base surface 86 and lug 74 of the metal base 84. In such embodiments, both structures, namely the metal base 84 and the porous metal coating 32, can be manufactured simultaneously in a common additive manufacturing process. For example, the two structures can be manufactured simultaneously in a single 3D printing operation that produces a common integral metal part comprising both structures. Alternatively, the porous metal coating 32 can be manufactured as a separate component fixed to the metal base 84.

[0054] The polymer joint layer 82 can be assembled to the metal base 84 using a number of different techniques. One exemplary method for doing so is by using compression molding. For example, the metal base 84 and the material from which the polymer joint layer 82 is to be manufactured (e.g., PEEK) can be placed in a mold. The parts are then compression molded together under process parameters that allow the material from which the polymer joint layer 82 is manufactured (e.g., PEEK) to be melted and mechanically fixed to the metal base 84 by the compression molding process. As described above, when molding to the ribs 90 of the metal base 84, the molten polymer joint layer 82 is interlaced with the ribs (i.e., the molten polymer joint layer 82 is injected into the grooves 102 defined by the ribs 90). It should also be understood that the mold can be configured not only to mold the parts together but also to form the articular surface 50 of the femoral part 12 into the polymer joint layer 82. Another exemplary and equally effective method for assembling the polymer joint layer 82 to the metal base 84 is by using injection molding.

[0055] Starting materials (e.g., polymers, such as PEEK) used in molding processes can be provided in many different forms. For example, each of the starting materials can be provided as a preform. The term "preform" herein refers to an article that has been solidified into a rod, sheet, block, slat, etc., such as by stamping or compression molding of polymer resin particles. The term "preform" also includes preformed "discs" which can be prepared by intermediate machining of commercially available preforms. Polymer preforms can be provided in many different pretreatment or preconditioning variations. For example, crosslinked or non-crosslinked (e.g., irradiated or unirradiated) preforms can be used. Such preforms can be treated to eliminate (e.g., remelt or quench) or stabilize (e.g., by adding vitamin E as an antioxidant) any free radicals present therein. Alternatively, preforms may not be treated in this way.

[0056] Starting materials (e.g., polymers, copolymers, and / or blends) may also be provided as powders or spheres. The terms "powder" and "spheres" refer herein to resin particles. Similar to what has been described above regarding preforms, powders and / or spheres can be provided in many different pre-treatment or pre-conditioning variants. For example, cross-linked or non-cross-linked (e.g., irradiated or unirradiated) powders and / or spheres can be utilized. Furthermore, in the case of blends, powders and / or spheres can be provided as pre-blended resin particles or blended in situ in a hopper associated with a molding machine to produce the desired blend composition for the molding process.

[0057] As described herein, the metal-reinforced femoral component 12 has certain reinforcing properties. For example, the use of a ribbed metal base 84 increases the overall stiffness of the component and produces a uniform wall thickness for precise injection molding of the polymer articular layer 82.

[0058] In some designs of the femoral component 12, alternatives to using the metal base 84 include spray coating. For example, a titanium plasma spray (TPS) coating can be applied to a previously molded polymer femoral component to provide a metallic layer on the dorsal side of the component. Another alternative method is to use a two-shot molding process. In this case, the polymer articular layer 82 is formed in a first spray, and then a porous coating is applied to the dorsal side of the articular layer 82 by a second spray filled with a pore-forming agent.

[0059] Although the present disclosure has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be regarded as exemplary rather than limiting in nature. It should be understood that only exemplary embodiments have been shown and described, and all changes and modifications made within the substance of the present disclosure should be protected.

[0060] The methods, apparatus, and systems described herein possess numerous advantages due to their various features. It should be noted that alternative embodiments of the methods, apparatus, and systems of this disclosure may exclude all described features, but may still benefit from at least some of the advantages of such features. Those skilled in the art will readily conceive of their own implementations of the methods, apparatus, and systems described above, which may incorporate one or more features of the invention and fall within the spirit and scope of this disclosure as defined by the appended claims.

Claims

1. A plastic surgery knee joint prosthesis, the plastic surgery knee joint prosthesis comprising: Femoral component, the femoral component comprising: A metal base comprising (i) a lower base surface curved in a longitudinal bisecting plane, the lower base surface having a plurality of elongated ribs extending downward therefrom; and (ii) an upper base surface having (a) a rear fixing surface extending generally in an up / down direction, (b) a distal fixing surface extending generally in a front / back direction, (c) a rear inclined fixing surface extending upward and backward from the distal fixing surface in a direction toward the rear fixing surface, (d) a front fixing surface extending generally in the up / down direction, and (e) a front inclined fixing surface extending upward and forward from the distal fixing surface in a direction toward the front fixing surface, and A polymer joint layer, molded onto the lower base surface of the metal base and molded into a plurality of elongated grooves defined by the plurality of ribs, the polymer joint layer having an articulation surface that is curved in the longitudinal dividing plane and configured to hinge with a support surface of the tibial component.

2. The orthopedic knee prosthesis according to claim 1, wherein a porous metal coating is disposed on the upper base surface of the metal base.

3. The orthopedic knee prosthesis of claim 1, wherein a porous metal coating is disposed on the entirety of each of the posterior fixation surface, the distal fixation surface, the posterior inclined fixation surface, the anterior fixation surface, and the anterior inclined fixation surface of the upper base surface of the metal base.

4. The orthopedic knee prosthesis according to claim 1, wherein: The metal base includes a plurality of lugs extending upward from the distal fixing surface, and A porous metal coating is applied to the upper base surface of the metal base and the lug.

5. The orthopedic knee prosthesis of claim 1, wherein the lower end of each of the plurality of ribs is formed therein with an undercut.

6. The orthopedic knee prosthesis of claim 5, wherein the lower end of the plurality of ribs defining the undercut includes a circular surface.

7. The orthopedic knee prosthesis of claim 1, wherein the plurality of ribs extend in the longitudinal bisecting plane.

8. The orthopedic knee prosthesis of claim 1, wherein the plurality of ribs extend in the coronal plane.

9. The orthopedic knee prosthesis of claim 1, wherein the plurality of ribs are fully embedded in the polymer joint layer.

10. The orthopedic knee prosthesis of claim 1, wherein a plurality of the plurality of ribs are hollow.

11. The orthopedic knee prosthesis of claim 1, wherein the polymeric joint layer of the femoral component comprises polyaryletherketone (PAEK).

12. A plastic surgery knee joint prosthesis system, the plastic surgery knee joint prosthesis system comprising: A tibial component, configured for implantation on the proximal end of a patient's tibia, the tibial component including a concave support surface, and A femoral component, configured for implantation on the distal end of a patient's femur, the femoral component comprising: A metal base comprising (i) a lower base surface curved in a longitudinal bisecting plane and having a plurality of elongated ribs extending downward from the lower base surface, and (ii) an upper base surface having (a) a plurality of bone fixation surfaces and (b) a plurality of lugs extending upward from one of the plurality of bone fixation surfaces. A porous metal coating is disposed on the upper base surface of the metal base and the lug, and A polymer joint layer, molded onto the lower base surface of the metal base and molded into a plurality of elongated grooves defined by the plurality of ribs, the polymer joint layer having an articulation surface that is curved in the longitudinal dividing plane and configured to hinge with the support surface of the tibial component.

13. The orthopedic knee prosthesis system of claim 12, wherein the plurality of bone fixation surfaces of the upper base surface comprises: A rear fixing surface that extends generally in the up / down direction. A distal fixing surface that extends generally in the anterior / rear direction. A rear inclined fixing surface, the rear inclined fixing surface extending upward and rearward from the distal fixing surface in a direction toward the rear fixing surface. A front fixing surface that extends generally in the up / down direction, and a front inclined fixing surface that extends upward and forward from the distal fixing surface in a direction toward the front fixing surface.

14. The orthopedic knee prosthesis system of claim 13, wherein the porous metal coating is disposed on the entirety of each of the posterior fixation surface, the distal fixation surface, the posterior bevel fixation surface, the anterior fixation surface, and the anterior bevel fixation surface of the upper base surface of the metal base.

15. The orthopedic knee prosthesis system of claim 12, wherein the lower end of each of the plurality of ribs is formed therein with an undercut.

16. The orthopedic knee prosthesis system of claim 15, wherein the lower end of the plurality of ribs defining the undercut includes a circular surface.

17. The orthopedic knee prosthesis system of claim 12, wherein the plurality of ribs extend in the longitudinal bisecting plane.

18. The orthopedic knee prosthesis system of claim 12, wherein the plurality of ribs extend in the coronal plane.

19. The orthopedic knee prosthesis system of claim 12, wherein the plurality of ribs are fully embedded in the polymer joint layer.

20. The orthopedic knee prosthesis of claim 12, wherein a plurality of the plurality of ribs are hollow.

21. The orthopedic knee prosthesis system of claim 12, wherein the polymeric joint layer of the femoral component comprises polyaryletherketone (PAEK).

22. A method for fabricating a femoral component of an orthopedic knee joint prosthesis, the method comprising: A porous metal coating is applied to a metal base having (i) an upper base surface including a plurality of bone fixation surfaces, and (ii) a plurality of lugs, and a polymer articulation layer is molded onto a lower base surface of the metal base that is curved in the longitudinal bisecting plane such that (i) a plurality of elongated ribs extending downward from the lower base surface are embedded in the polymer articulation layer, and (ii) the outer surface of the polymer articulation layer forms an articulation surface that is curved in the longitudinal bisecting plane and configured to hinge with a support surface of the tibial component.

23. The method of claim 22, wherein applying the porous metal coating to the upper base surface and the plurality of lugs of the metal base comprises 3D printing the porous metal coating and the metal base as an integral metal part.

24. The method of claim 22, wherein: The lower end of each of the plurality of ribs has an undercut therein, and Molding the polymer joint layer onto the lower base surface of the metal base includes molding the polymer joint layer onto the lower base surface of the metal base such that the polymer joint layer is molded onto the undercut of each of the plurality of ribs.

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