Patent Description:
The embodiments disclosed herein are generally directed towards porous metal structures and, more specifically, to porous metal structures in medical devices. The methods disclosed herein do not form part of the claimed invention.

The embodiments disclosed herein are generally directed towards surface features for three-dimensional porous structures for bone ingrowth and methods for producing said structures.

The field of rapid prototyping and additive manufacturing has seen many advances over the years, particularly for rapid prototyping of articles such as prototype parts and mold dies. These advances have reduced fabrication cost and time, while increasing accuracy of the finished product, versus conventional machining processes, such as those where materials (e.g., metal) start as a block of material, and are consequently machined down to the finished product.

However, the main focus of rapid prototyping three-dimensional structures has been on increasing density of rapid prototyped structures. Examples of modern rapid prototyping/additive manufacturing techniques include sheet lamination, adhesion bonding, laser sintering (or selective laser sintering), laser melting (or selective laser sintering), photopolymerization, droplet deposition, stereolithography, 3D printing, fused deposition modeling, and 3D plotting. Particularly in the areas of selective laser sintering, selective laser melting and 3D printing, the improvement in the production of high density parts has made those techniques useful in designing and accurately producing articles such as highly dense metal parts.

In the field of tissue engineering, a porous three-dimensional biocompatible scaffold is needed to accommodate mammalian cells and promote their three-dimensional growth and regeneration, and thus can be used for example, as implants/prosthetic components or other prostheses. Furthermore, this scaffold, or ingrowth coating, requires sufficient surface texture to promote stable implant-bone interface essential for rapid and effective bone ingrowth. Fixation features (e.g., pegs) with higher fixation strength limit, for example, the implant-to-bone motion and increase opportunity for bony in-growth more than pegs that are not well fixated in the bone.

<CIT> is an example of an orthopaedic prosthetic component provided with a porous three-dimensional structure for permitting bone in growth, with fixation pegs also provided with the porous structure. <CIT> , <CIT> and <CIT> are further examples of joint prostheses and porous structures.

According to one aspect of the disclosure, an orthopaedic prosthetic component is disclosed, the orthopaedic prosthetic component comprises a base and a fixation peg extending away from the base to a distal tip, the fixation peg includes a porous three-dimensional structure configured to permit bone in-growth, the porous three-dimensional structure having an outer surface boundary, wherein the fixation peg includes a plurality of plates attached to the porous three-dimensional structure at the outer surface boundary, each plate including a tapered body having an outer wall that faces away from the porous three-dimensional structure and is devoid of any openings, the tapered body of each plate extends from a proximal end to a distal end, and the tapered body of each plate has a first thickness at the distal end and a second thickness greater than the first thickness between the proximal end and the distal end, each plate may extend circumferentially around the porous three-dimensional structure. Additionally, in some embodiments, adjacent plates of the plurality of plates may be spaced apart from each other on the porous three-dimensional structure in a proximal-distal direction.

In some embodiments, the tapered body of each plate may extend longitudinally along the porous three-dimensional structure. Additionally, in some embodiments, the tapered body of each plate may have a first width at the proximal end and a second width greater than the first width between the proximal end and the distal end.

In some embodiments, the outer wall of each plate may include a concave surface that defines a tapered channel. In some embodiments, each plate is a solid plate that is devoid of any openings or through-holes.

In some embodiments, the plurality of plates may be arranged circumferentially on the porous three-dimensional structure. Additionally, in some embodiments, adjacent plates of the plurality of plates may be spaced apart circumferentially from each other on the porous three-dimensional structure.

In some embodiments, the plurality of plates may be positioned between the distal tip of the fixation peg and the base. Additionally, in some embodiments, the base may include a tibial platform configured to receive a tibial insert. In some embodiments, an elongated stem may extend from the tibial platform to a distal tip. The elongated stem may be configured to be implanted in a surgically-prepared proximal end of a patient's tibia.

In some embodiments, the orthopaedic prosthetic component may further comprise a porous three-dimensional layer attached to a distal surface of the tibial platform. The elongated stem may extend outwardly from the three-dimensional layer, and the fixation peg extends outwardly from the porous three-dimensional layer.

In some embodiments, the distal tip of the fixation peg may include a longitudinal slot.

According to another embodiment, the orthopaedic prosthetic component comprises a tibial platform configured to receive a tibial insert and a porous three-dimensional structure coupled to the tibial platform. The porous three-dimensional structure is configured to permit bone in-growth. The orthopaedic prosthetic component also comprises an elongated stem extending away from the tibial platform to a distal tip. The porous three-dimensional structure includes a layer coupled to the tibial platform and a plurality of fixation pegs extending from the layer. Each fixation peg includes a portion of the porous three-dimensional structure that has an outer surface boundary. A plurality of plates are attached at the outer surface boundary of each fixation peg. Each plate includes a tapered body having an outer wall that is devoid of any openings.

In some embodiments, the tapered body of each plate may extend longitudinally along the porous three-dimensional structure. Additionally, in some embodiments, the outer wall of each plate may include a concave surface that defines a tapered channel.

In some embodiments, adjacent plates of the plurality of plates may be spaced apart circumferentially from each other on each peg. In some embodiments, adjacent plates of the plurality of plates may be spaced apart from each other on the porous three-dimensional structure in a proximal-distal direction.

Aa method for producing an orthopaedic prosthetic component, not forming part of the claimed invention, is disclosed, useful as background only. The method comprises depositing and scanning successive layers of metal powders to form a porous three-dimensional structure comprising at least one fixation peg. The at least one fixation peg comprises a porous portion and at least one solid plate positioned on the porous portion.

An orthopaedic implant is disclosed, useful as background only. The implant comprises a porous three-dimensional structure and at least one fixation feature extending past a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the implant further comprises a base that is anchored to a second side of the porous three-dimensional structure.

In some embodiments, the fixation feature is further comprised of a length that is greater than a width.

In some embodiments, the fixation feature is further comprised of a width that is greater than a length.

In some embodiments, the plurality of solid portions extend outwardly from the surface boundary of the porous three-dimensional structure.

In some embodiments, the plurality of solid portions are positioned substantially parallel to the surface boundary of the porous three-dimensional structure.

In some embodiments, the fixation feature is further comprised of a porous tip portion distal to the porous three-dimensional structure.

In some embodiment, the implant is further comprised of a plurality of fixation features.

In some embodiments, the porous portion further includes a plurality of scallops. In some embodiments, each of the plurality of solid portions occupy a respective scallop. In some embodiments, each of the plurality of scallops is comprised of a distal region that is larger than a proximal region.

In some embodiments, at least one of the plurality of solid portions is attached to a porous portion. In some embodiments, the plurality of solid portions tapers in the distal direction. In some embodiments, each of the plurality of solid portions is attached to a porous portion. In some embodiments, each of the plurality of solid portions tapers in a distal direction. In some embodiments, the thickness of each respective solid portion is less than the solid portion immediately proximal.

In another orthopaedic implant is disclosed, useful as background only, the implant comprises a porous three-dimensional structure including at least one fixation feature. The one fixation feature comprises a porous portion having an interior, at least one solid portion and at least one slot that is partially located on the interior of the porous portion.

In some embodiments, the at least one solid portion is positioned on an outside surface of the porous portion.

In some embodiments, the implant is further comprised of a base that is anchored to a second side of the porous three-dimensional structure.

In some embodiments, the fixation feature is comprised of a width that is greater than the length.

In some embodiments, the fixation feature is comprised of a length that is greater than the width.

In some embodiments, the at least one solid portion is positioned substantially perpendicular to the surface boundary of the porous three-dimensional structure.

In some embodiments, the at least one solid portion extends to a tip region of the at least one fixation feature that is distal to the porous three-dimensional structure.

In some embodiments, the implant is further comprised of a plurality of fixation features.

In some embodiments, the at least one solid portion includes at least one barb that tapers in the distal direction. In some embodiments, the at least one solid portion includes a plurality of barbs. In some embodiments, the thickness of each respective barb is less than the barb immediately proximal.

In some embodiments, the at least one solid portion is attached to the porous portion.

In some embodiments, the at least one solid portion tapers in the distal direction.

In some embodiments, the implant is comprised of a plurality of solid portions. In some embodiments, each of the plurality of solid portions attaches to the porous portion. In some embodiments, each of the plurality of solid portions tapers in the distal direction. In some embodiments, each of the plurality of solid portions includes at least one barb that tapers in the distal direction.

In some embodiments, the at least one slot provides an opening at a tip region of the at least one fixation feature.

In some embodiments, the implant is comprised of a plurality of slots.

A a method for producing an orthopaedic implant, not forming part of the claimed invention, is disclosed, useful as background only. The method comprises depositing and scanning successive layers of metal powders to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The at least one fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion having an interior, at least one solid portion and at least one slot at least partially located on the interior of the porous portion.

In some embodiments, the method further comprises providing a base and anchoring a second side of the porous three-dimensional structure to the base.

In yet another method for producing a porous three-dimensional structure is disclosed, useful as background only, that the method comprises depositing and scanning successive layers of metal powders with a beam to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The at least one fixation feature is anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the beam is an electron beam.

In some embodiments, the beam is a laser beam.

In some embodiments, the metal powders are melted to form the porous three-dimensional structure.

In some embodiments, the metal powders are sintered to form the porous three-dimensional structure.

In some embodiments, the successive layers of metal powders are deposited onto a solid base.

In another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises applying a stream of metal particles at a predetermined velocity onto a base to form a porous three-dimensional structure and to form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the method further comprises anchoring a second side of the porous three-dimensional structure to the base.

In some embodiments, the predetermined velocity is a critical velocity required for the metal particles to bond upon impacting the base. In some embodiments, the critical velocity is greater than about <NUM>/s.

In some embodiments, the method further comprises applying a laser beam at a predetermined power setting onto an area of the base where the stream of metal particles is impacting.

In another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises introducing a continuous feed of metal wire onto a base surface and applying a beam at a predetermined power setting to an area where the metal wire contact the base surface to form a porous three-dimensional structure and to form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In yet another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises introducing a continuous feed of polymer material embedded with metal elements onto a base surface, applying heat to an area where the polymer material contacts the base surface to form porous three-dimensional structure and to form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the method further includes scanning the porous three-dimensional structure with a beam to burn off the polymer material.

In some embodiments, the heat is applied using a heating element. In some embodiments, the heating element is part of a furnace system.

In another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises introducing a metal slurry through a nozzle onto a base surface to form a porous three-dimensional structure and at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In yet another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises introducing successive layers of molten metal onto a base surface to form a porous three-dimensional structure and at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In another method for producing a porous three-dimensional structure is disclosed, , useful as background only, the method comprises depositing and binding successive layers of metal powders with a binder material to form a porous three-dimensional structure and at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the method further includes sintering or melting the bound metal powder with a beam. In some embodiments, the beam is an electron beam. In some embodiments, the beam is a laser beam.

In some embodiments, the method further includes sintering or melting the bound metal powder with a heating element.

In yet another method for producing a porous three-dimensional structure is disclosed, useful as background only, the method comprises depositing droplets of a metal material onto a base surface and applying heat to an area where the metal material contacts the base surface to form a porous three-dimensional structure and at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The porous three-dimensional structure is comprised of a plurality of unit cells. The fixation feature is anchored to a first side of the porous three-dimensional structure and is comprised of a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

In some embodiments, the heat is applied with an electron beam.

In some embodiments, the heat is applied with a laser beam.

In some embodiments, the metal material is a metal slurry embedded with metallic elements.

In some embodiments, the metal material is a metal powder.

This specification describes exemplary embodiments and applications of the disclosure. The disclosure, however, is not limited to these exemplary embodiments and applications or to the manner in which the exemplary embodiments and applications operate or are described herein. Moreover, the figures may show simplified or partial views, and the dimensions of elements in the figures may be exaggerated or otherwise not in proportion. In addition, as the terms "on," "attached to," "connected to," "coupled to," or similar words are used herein, one element (e.g., a material, a layer, a base, etc.) can be "on," "attached to," "connected to," or "coupled to" another element regardless of whether the one element is directly on, attached to, connected to, or coupled to the other element, there are one or more intervening elements between the one element and the other element, or the two elements are integrated as a single piece. Also, unless the context dictates otherwise, directions (e.g., above, below, top, bottom, side, up, down, under, over, upper, lower, horizontal, vertical, "x," "y," "z," etc.), if provided, are relative and provided solely by way of example and for ease of illustration and discussion and not by way of limitation. In addition, where reference is made to a list of elements (e.g., elements a, b, c), such reference is intended to include any one of the listed elements by itself, any combination of less than all of the listed elements, and/or a combination of all of the listed elements. Section divisions in the specification are for ease of review only and do not limit any combination of elements discussed.

As used herein, "bonded to" or "bonding" denotes an attachment of metal to metal due to a variety of physicochemical mechanisms, including but not limited to: metallic bonding, electrostatic attraction and/or adhesion forces.

Unless otherwise defined, scientific and technical terms used in connection with the present teachings described herein shall have the meanings that are commonly understood by those of ordinary skill in the art.

The present disclosure relates to porous three-dimensional metallic structures and methods for manufacturing them for medical applications. As described in greater detail below, the porous metallic structures promote hard or soft tissue interlocks between prosthetic components implanted in a patient's body and the patient's surrounding hard or soft tissue. For example, when included on an orthopaedic prosthetic component configured to be implanted in a patient's body, the porous three-dimensional metallic structure can be used to provide a porous outer layer of the orthopaedic prosthetic component to form a bone in-growth structure. Alternatively, the porous three-dimensional metallic structure can be used as an implant with the required structural integrity to both fulfill the intended function of the implant and to provide interconnected porosity for tissue interlock (e.g., bone in-growth) with the surrounding tissue.

In accordance with various embodiments, an orthopaedic prosthetic component is provided, the prosthetic component including a base, a porous three-dimensional structure, and at least one surface feature (hereinafter referred to as an engagement stud) extending past a surface boundary of the porous three-dimensional structure. The porous structure can include a plurality of unit cells.

The orthopaedic implant/prosthetic component, by design, can be a surgical implant configured for implantation into a patient's bone. For example, as shown in <FIG>, an orthopaedic prosthetic component <NUM> is a tibial tray of a total knee arthroplasty prosthesis. The component <NUM> includes a platform <NUM> having a stem <NUM> extending away from its lower surface <NUM>. The tibial stem <NUM> extends to a distal tip <NUM> and is configured to be implanted into a surgically-prepared proximal end of a patient's tibia (not shown). The platform <NUM> also has an upper surface <NUM> positioned opposite the lower surface <NUM> and a curved outer wall <NUM> that extends between the surfaces <NUM>, <NUM>. In the illustrative embodiment, the curved outer wall <NUM> is shaped to correspond to the outer edge of a surgically-prepared surface on the proximal end of the patient's tibia. The platform <NUM> also has various engagement features (not shown) attached to the upper surface <NUM>, which are configured to engage an insert or bearing of the total knee arthroplasty prosthesis. Exemplary engagement features, as well as exemplary other components of the knee arthroplasty prosthesis, are shown and described in <CIT>.

The platform <NUM> of the component <NUM> is constructed with a biocompatible metal, such as a cobalt chrome or titanium alloy, although other materials may also be used. As shown in <FIG>, the component <NUM> includes a three-dimensional ingrowth body <NUM>, which is attached to the lower surface <NUM> of the platform <NUM> such that the platform <NUM> provides a base for the ingrowth body <NUM>. The ingrowth body <NUM> includes a porous three-dimensional structure <NUM> that is configured to promote bone ingrowth for permanent fixation, as described in greater detail below.

In the illustrative embodiment, the ingrowth body <NUM> includes a layer or plate <NUM> attached to the lower surface <NUM> of the platform <NUM> and a number of pegs <NUM> that extend outwardly from the plate <NUM>. The ingrowth body <NUM> is also attached to the stem <NUM>, which extends outwardly through the layer <NUM> to its distal tip <NUM>. It should be appreciated that although a tibial prosthetic component is shown, the various porous structures described herein (including engagement stud structures described herein) can be incorporated into various orthopaedic implant designs such that the design of the implant will not impact the ability to use any of the various embodiments of engagement studs discussed herein. For example, the porous structures described herein may be included in a femoral prosthetic component similar to the femoral component shown in <CIT> or on a patella component shaped to engage the femoral prosthetic component. The porous structures may also be included in other orthopaedic implant designs, including prosthetic components for use in a hip or shoulder arthroplasty surgery.

It should be noted, for the preceding and going forward, that a base can be any type of structure capable of, for example, contacting, supporting, connecting to or with, or anchoring to or with components of various embodiments herein. Bases can include, for example, a metal or non-metal platform, a metal or non-metal tray, a metal or non-metal baseplate, a metal or non-metal structure that sits on a tray, and so on.

Referring now to <FIG>, one fixation peg <NUM> is shown in greater detail. In the illustrative embodiment, each of the pegs <NUM> has an identical configuration. The ingrowth body <NUM> (and hence each peg <NUM>) includes a porous three-dimensional structure <NUM> that includes a plurality of unit cells <NUM>, each made up multiple struts <NUM>. The plurality of unit cells <NUM> are provided in repeating patterns to form the structure <NUM>, which has an outer surface boundary <NUM>. The unit cells <NUM> define pores or voids that permit bone ingrowth after the orthopaedic prosthetic component <NUM> is implanted in the patient's bone, thereby promoting fixation between the component <NUM> and the surrounding bone tissue.

Each fixation peg <NUM> extends from a proximal end <NUM> attached to the layer <NUM> of the ingrowth body <NUM> to a distal end <NUM>. In the illustrative embodiment, the fixation pegs <NUM> and the layer <NUM> are formed as a single monolithic porous component. It should be appreciated that in other embodiments the layer <NUM> may be formed separately from one or more of the fixation pegs <NUM> and later assembled with the peg(s). It should also be appreciated that one or more of the fixation pegs may be attached directed to the platform <NUM> and extend through the layer <NUM>.

Each fixation peg <NUM> extends along a longitudinal axis <NUM> between the ends <NUM>, <NUM>. As shown in the cross-section of <FIG>, the outer surface boundary <NUM> of each peg <NUM> extends circumferentially around the longitudinal axis <NUM>. In the illustrative embodiment, the outer surface boundary <NUM> includes a convex section <NUM> and a number of concave sections <NUM> that define grooves or channels <NUM> within the convex section <NUM>. The fixation peg <NUM> includes a plurality of plates <NUM>, which are attached at the surface boundary <NUM> within the grooves and are configured to reduce bone abrasion, as described in greater detail below. In other embodiments, the profile of the surface boundary may be more or less uneven than the illustrative embodiment to receive plates of other designs.

In the illustrative embodiment, each groove <NUM> has a scallop-shape that is tapered. Each of the plurality of plates <NUM> occupies a respective scallop. Each of the grooves <NUM> comprises a distal region and proximal region, wherein a portion of the distal region is larger than the proximal region. Alternatively, one or more of the plurality of grooves can comprise a distal region and proximal region, wherein the distal region is smaller than the proximal region.

The plates <NUM> are arranged circumferentially on the surface boundary <NUM> of the porous three-dimensional structure <NUM> of each fixation peg <NUM>. In the illustrative embodiment, the plates <NUM> are spaced apart from one another by the porous three-dimensional structure <NUM>. Returning to <FIG>, each plate <NUM> has a tapered body <NUM> that extends along the longitudinal axis <NUM> from a proximal end <NUM> to a distal end <NUM>. The tapered body <NUM> of each plate <NUM> has an outer wall <NUM> that faces away from the porous three-dimensional structure <NUM>. In the illustrative embodiment, the outer wall <NUM> is devoid of any openings, and the tapered body <NUM> is a solid material without any through-holes. It should be appreciated that in other embodiments portions of the outer wall <NUM> may include openings or through-holes depending on the configuration of the plate and the orthopaedic application.

Each tapered body <NUM> comprises a distal region <NUM> including the distal end <NUM> and a proximal region <NUM> including the proximal end <NUM>, wherein the distal region includes a portion that is larger than the proximal region. Alternatively, the occupying solid portions can comprise a distal region and proximal region, and the distal region includes a portion that is smaller than the proximal region. As shown in <FIG>, each tapered body <NUM> has a width <NUM> in the proximal region <NUM> (illustratively at the proximal end <NUM>) and tapers to another, larger width <NUM> in the distal region <NUM> (but illustratively between the ends <NUM>, <NUM>).

The outer wall <NUM> of each tapered body <NUM> includes a concave surface <NUM> that defines a channel <NUM> that is tapered to correspond to the tapering of the body <NUM>. Each channel <NUM> has an open distal end to facilitate insertion of the peg <NUM> into a patient's bone. It should be appreciated that in other embodiments channels <NUM> may have different configurations. As shown in <FIG>, the distal end <NUM> of each plate <NUM> is positioned proximal of the distal tip <NUM> of each fixation peg <NUM> such that the plates are positioned between the distal tip <NUM> and the platform <NUM> of the orthopaedic prosthetic component. It should be appreciated that in other embodiments the distal end of the plate may be positioned at the distal tip such that they are aligned in a distal plane.

In various embodiments, and as stated above, the solid material can be a metal or non-metal, and the types of metal can include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium. Non-metal examples include, for examples, ceramic materials (e.g., titanium nitride) and carbon materials (e.g., silicon carbide).

By providing a combination of solid components and porous components, the fixation pegs are configured to reduce bone abrasion and increase fixation strength, while still having the porous structure necessary for promoting bone in-growth and also allowing, as needed, for ease of revision (e.g., cutting through the pegs).

As described above, each fixation peg <NUM> has a porous structure with solid portions positioned at the surface boundary of the porous structure. It should be appreciated that in other embodiments the fixation peg or feature may have a solid core. For example, as shown in <FIG>, a fixation peg <NUM> has a solid core embedded therein. In <FIG>, the fixation feature <NUM> comprises a porous portion <NUM> and a plurality of solid plates <NUM> (or a plurality of solid portions <NUM>). The porous portion <NUM> furthers include a core <NUM> of solid material. In <FIG>, the porous portion <NUM> is substantially replaced by a solid core <NUM>. Providing such a solid core, in either case, may potentially provide additional strength to the fixation feature overall to withstand the stress of being embedded in tissue such as bone or for cleaning purposes as needed.

Referring now to <FIG>, other examples of fixation features are illustrated, in accordance with various embodiments. In <FIG> and <FIG>, a fixation feature <NUM> (illustratively another fixation peg) is provided, with the feature <NUM> comprising a porous three-dimensional structure or portion <NUM> and at least one solid plate or portion <NUM>. In various embodiments, and as illustrated in <FIG>, the fixation feature <NUM> can comprise a plurality of solid portions <NUM>. At least one of the plurality of solid portions can be attached to a surface of the porous portion <NUM>. In <FIG>, each of the plurality of solid portions <NUM> is attached to a porous portion <NUM>.

As shown in <FIG>, each of the plurality of solid portions <NUM> tapers in the distal direction such that the thickness of each respective solid portion is less than the solid portion immediately proximal. In other words, as shown in <FIG>, each solid portion <NUM> has a thickness <NUM> at its distal end <NUM> and another, greater thickness <NUM> proximal of the distal end <NUM> (illustratively between the distal end <NUM> and the proximal end <NUM> of the portion <NUM>). This representative thickness difference between succeeding solid portions presents an overall tapering effect across the solid portions take together, as illustrated, for example, by the successive narrowing of solid portions <NUM> as fixation feature <NUM> proceeds distally.

As shown in <FIG>, each of the solid plates or portions <NUM> extend circumferentially around the porous portion <NUM>. Adjacent portions <NUM> of the plurality of portions <NUM> are spaced apart from each other on the porous portion <NUM> in a proximal-distal direction.

By providing a design similar to that illustrated, for example, in <FIG> and <FIG>, the solid portions can reduce bone abrasion and increase hoop stresses in the bone. However, with the porous portion, the fixation feature provides regions for bone in-growth and ease of revision. Moreover, by providing designs with a tapering solid portion or plurality of solid portions, the most distal portion of the solid portion may provide a cutting path into the bone that would not disturb bone needed to secure subsequent regions of the solid portion (or subsequent solid portions of the plurality of solid portions).

Referring now to <FIG>, another fixation feature (hereinafter feature <NUM>) is provided. The fixation feature <NUM> extends from a layer of a porous three-dimensional structure <NUM> attached to the platform of the tibial prosthetic component. The fixation feature <NUM>, like the pegs and features of <FIG>, is configured to engage a patient's bone. Similar to the pegs <NUM> described above, the fixation feature <NUM> may be part of a porous three-dimensional structure attached to a solid platform. In such embodiments, a second side <NUM> of porous three-dimensional structure <NUM> may be anchored to the platform. Additionally, the fixation feature <NUM> may be one of a number of fixation features <NUM>. It should also be appreciated that the porous structure <NUM> can be a solid, or substantially solid, structure. As shown in <FIG>, each fixation feature <NUM> includes a porous portion <NUM> that is anchored to a first side of the layer of structure <NUM>. The porous portion <NUM> has a plurality of voids or openings that extend through the porous portion <NUM> and open into an interior <NUM>.

The fixation feature <NUM> extends to a distal tip <NUM>, and a solid portion <NUM> is positioned at the distal tip <NUM> on an outside surface <NUM> of the porous portion <NUM>. In accordance with various embodiments, and as illustrated for example in <FIG>, the solid portion includes a number of plates or barbs <NUM> that are positioned substantially perpendicular to the surface boundary of the porous portion <NUM>. Each barb <NUM> illustratively tapers in the distal direction (e.g., towards distal tip <NUM> of fixation feature <NUM>). As shown in <FIG>, the thickness of each respective barb is less than the barb immediately proximal, and this representative thickness difference between succeeding barbs presents an overall tapering effect across the solid portion <NUM> by the narrowing of solid portion <NUM> as fixation feature <NUM> proceeds distally towards tip region <NUM>. Thus, the at least one solid portion can taper in the distal direction. In other embodiments, the solid portion <NUM> may not taper. It should also be appreciated that in other embodiments the solid portion <NUM> may include additional or fewer barbs <NUM>. As illustrated in <FIG> for example, the solid portion <NUM> surrounds the porous portion <NUM>.

The fixation feature <NUM> also includes an elongated slot <NUM> that extends from an opening <NUM> at the distal tip <NUM>. As shown in <FIG>, the elongated slot <NUM> extends through the interior <NUM> of the porous portion <NUM>. The solid portion <NUM> illustratively includes an inside surface <NUM> that defines the slot <NUM>. In other embodiments, the elongated slot <NUM> may be defined by a solid portion separate from the barbs <NUM>. It should also be appreciated that in other embodiments the inside surface <NUM> may be porous or partially porous.

In accordance with various embodiments, the fixation feature can further comprise a length and a width, wherein the length is greater than the width (as illustrated in <FIG>). The fixation feature can further comprise a length and a width, wherein the width is greater than the length.

As stated above, in various embodiments, the fixation feature can comprise a plurality of solid portions. Each of the plurality of solid portions can surround the porous portion. Each of the plurality of solid portions can taper in the distal direction. Each of the plurality of solid portions can include at least one barb, wherein the at least one barb tapers in the distal direction.

By providing a fixation feature with a slot as illustrated, for example, in <FIG>, the fixation feature can deflect during fixation feature insertion to help prevent bone abrasion. The porous portion assists in providing the low modulus necessary for deflection of the fixation features, or more specifically the barbs on the solid portion, while also allowing for sufficient bone in-growth and ease of revision. It should also be noted that, while <FIG> illustrates a single slot, a plurality of slots could be used (e.g., <NUM> to <NUM> slots) to minimize any directionality of the slotted design.

Referring now to <FIG>, a chart <NUM> is provided to show extraction/insertion force ratio results from fixation feature pull-out testing for various designs. Each fixation feature was inserted and extracted from bone, with ratios calculated for each tested fixation feature indicative of the force of insertion versus the force of extraction. As such, high ratios would indicate any of a number of advantageous features for a given fixation feature including, for example, ease of fixation feature insertion into tissue and resistance to extraction, which would be indicative of fixation feature stability in the tissue (e.g., bone).

The three highlighted results are examples described by the concepts illustrated in <FIG> and described in detail above. The result <NUM> illustrates the performance of a peg <NUM> (see <FIG>), and the result <NUM> illustrates the performance of the fixation feature <NUM> (see <FIG>), while the result <NUM> illustrates the performance of the fixation feature <NUM> (see <FIG>). The three highlighted concepts performed as well as other pegs tested, which included devices similar to those with clinical usage. The results reinforce the advantageous nature of the various embodiments herein, which provide additional stability (e.g., as illustrated by the extraction/insertion force ratios of the embodiments disclosed herein).

The porous three-dimensional metallic structures disclosed above can be made using a variety of different metal component manufacturing techniques, including but not limited to: Casting Processes (casting processes involve pouring molten metal into a mold cavity where, once solid, the metal takes on the shape of the cavity. Examples include, expendable mold casting, permanent mold casting, and powder compaction metallurgy), Deformation Processes (deformation processes include metal forming and sheet metalworking processes which involve the use of a tool that applies mechanical stresses to metal which exceed the yield stress of the metal), Material Removal Processes (these processes remove extra material from the workpiece in order to achieve the desired shape. Examples of material removal processes include, tool machining and abrasive machining), and Additive Manufacturing Processes (these processes involve the use of digital 3D design data to build up a metal component up in layers by depositing successive layers of material). Additive Manufacturing Processes can include, only by way of example, powder bed fusion printing (e.g., melting and sintering), cold spray 3D printing, wire feed 3D printing, fused deposition 3D printing, extrusion 3D printing, liquid metal 3D printing, stereolithography 3D printing, binder jetting 3D printing, material jetting 3D printing, and so on. It should be appreciated, however, that additive manufacturing processes offer some unique advantages over the other metal component manufacturing techniques with respect to the manufacture of porous three-dimensional metallic structures (disclosed above) due to the complexities of the geometries and structural elements of the unit cells which comprise those types of structures.

In accordance with various embodiments, a method for producing an orthopaedic implant is provided, for example, by method <NUM> illustrated in <FIG>. The method can comprise depositing and scanning successive layers of metal powders with a beam to form a porous three-dimensional structure. The porous three-dimensional structure can comprise a plurality of unit cells and the depositing and scanning can form at least one fixation feature that extends beyond a surface boundary of the porous three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion having an interior, at least one solid portion, and at least one slot at least partially located on the interior of the porous portion. The beam (or scanning beam) can be an electron beam. The beam (or scanning beam) can be a laser beam.

As provided in <FIG>, step <NUM> includes depositing a layer of metal powder. Step <NUM> includes scanning a layer of metal powder. As provided in step <NUM>, the steps <NUM> and <NUM> are repeated until a porous three-dimensional structure is formed comprising a plurality of unit cells, and at least one fixation feature is formed that extends beyond a surface boundary of the porous-three-dimensional structure, wherein the at least one fixation feature is anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion.

Regarding the various methods described herein, the metal powders can be sintered to form the porous three-dimensional structure. Alternatively, the metal powders can be melted to form the porous three-dimensional structure. The successive layers of metal powders can be deposited onto a solid base (see above for discussion regarding base). In various embodiments, the types of metal powders that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium powders. In various embodiments, a second side of the porous three-dimensional structure can be anchored to the base.

In accordance with various embodiments, a method for producing an orthopaedic implant is provided. The method can comprise depositing and scanning successive layers of metal powders to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, providing a base, and anchoring a second side of the porous three-dimensional structure to the base.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise depositing and scanning successive layers of metal powders with a beam to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, providing a base, and anchoring a second side of the porous three-dimensional structure to the base. The beam can be an electron beam. The beam can be a laser beam. In various embodiments, the metal powders are sintered to form the porous three-dimensional structure. In various embodiments, the metal powders are melted to form the porous three-dimensional structure. In various embodiments, the successive layers of metal powders are deposited onto a solid base.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise applying a stream of metal particles at a predetermined velocity onto a base to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. The predetermined velocity can be a critical velocity required for the metal particles to bond upon impacting the base. The critical velocity can be greater than <NUM>/s. The method can further include applying a laser at a predetermined power setting onto an area of the base where the stream of metal particles is impacting. In various embodiments, the types of metal particles that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium particles.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise introducing a continuous feed of metal wire onto a base surface and applying a beam at a predetermined power setting to an area where the metal wire contacts the base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. The beam can be an electron beam. The beam can be a laser beam. In various embodiments, the types of metal wire that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium wire.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise introducing a continuous feed of a polymer material embedded with a metal element onto a base surface and applying heat to an area where the polymer material contacts the base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. In various embodiments, the continuous feed of polymer material can be supplied through a heated nozzle thus eliminating the need for applying heat to the area where the polymer material contacts the base surface to form the porous three-dimensional structures. In various embodiments, the types of metal elements that can be used to embed the polymer material can include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum and niobium.

The method can further include scanning the porous three-dimensional structure with a beam to burn off the polymer material. The beam (or scanning beam) can be an electron beam. The beam (or scanning beam) can be a laser beam.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise introducing a metal slurry through a nozzle onto a base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. In various embodiments, the nozzle is heated at a temperature required to bond the metallic elements of the metal slurry to the base surface. In various embodiments, the metal slurry is an aqueous suspension containing metal particles along with one or more additive (liquid or solid) to improve the performance of the manufacturing process or the porous three-dimensional structure. In various embodiments, the metal slurry is an organic solvent suspension containing metal particles along with one or more additive (liquid or solid) to improve the performance of the manufacturing process or the porous three-dimensional structure. In various embodiments, the types of metal particles that can be utilized in the metal slurry include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium particles.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise introducing successive layers of molten metal onto a base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. The molten metal can be introduced as a continuous stream onto the base surface. The molten metal can be introduced as a stream of discrete molten metal droplets onto the base surface. In various embodiments, the types of molten metals that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise applying and photoactivating successive layers of photosensitive polymer embedded with metal elements onto a base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. In various embodiments, the types of metal elements that can be used to embed the polymer material can include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise depositing and binding successive layers of metal powders with a binder material to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, a base and anchoring a second side of the porous three-dimensional structure to the base. In various embodiments, the types of metal powders that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium powders.

The method can further include sintering or melting the bound metal powder with a beam. The beam can be an electron beam. The beam can be a laser beam. The method can further include sintering or melting the bound metal powder with a heating element, where the beam is an electron beam, or the beam is a laser beam.

In accordance with various embodiments, a method for producing a porous three-dimensional structure is provided. The method can comprise depositing droplets of a metal material onto a base surface, and applying heat to an area where the metal material contacts the base surface to form a porous three-dimensional structure comprising a plurality of unit cells and to form at least one fixation feature that extends beyond a surface boundary of the porous-three-dimensional structure. The at least one fixation feature can be anchored to a first side of the porous three-dimensional structure and comprises a porous portion and a plurality of solid portions positioned on an outside surface of the porous portion. The method can further comprise, in various embodiments, anchoring a second side of the porous three-dimensional structure to the base. The heat can be applied with a beam, wherein the beam is an electron beam. The heat can be applied with a beam, wherein the beam is a laser beam. The metal material can be a metal slurry embedded with metallic elements. The metal material can be a metal powder. In various embodiments, the types of metal materials that can be used include, but are not limited to, titanium, titanium alloys, stainless steel, cobalt chrome alloys, tantalum or niobium.

Although specific embodiments and applications of the same have been described in this specification, these embodiments and applications are exemplary only, and many variations are possible.

While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.

Further, in describing various embodiments, the specification may have presented a method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the scope of the various embodiments.

Claim 1:
An orthopaedic prosthetic component [<NUM>], comprising:
a base [<NUM>],
a fixation peg [<NUM>] extending away from the base [<NUM>] to a distal tip [<NUM>], the fixation peg [<NUM>] including a porous three-dimensional structure [<NUM>] configured to permit bone in-growth, the porous three-dimensional structure [<NUM>] having an outer surface boundary [<NUM>],
characterized in that:
the fixation peg [<NUM>] includes a plurality of plates [<NUM>] attached to the porous three-dimensional structure [<NUM>] at the outer surface boundary [<NUM>], each plate [<NUM>] including a tapered body having an outer wall [<NUM>] that faces away from the porous three-dimensional structure [<NUM>] and is devoid of any openings;
the tapered body of each plate [<NUM>] extends from a proximal end [<NUM>] to a distal end [<NUM>], and
the tapered body of each plate [<NUM>] has a first thickness [<NUM>] at the distal end [<NUM>] and a second thickness [<NUM>] greater than the first thickness [<NUM>] between the proximal end [<NUM>] and the distal end [<NUM>];
each plate [<NUM>] extends circumferentially around the porous three-dimensional structure [<NUM>];
wherein adjacent plates [<NUM>] of the plurality of plates [<NUM>] are spaced apart from each other on the porous three-dimensional structure [<NUM>] in a proximal-distal direction.