Patent Description:
Knee arthroplasty or knee replacement procedures generally involve the implantation, installation, etc. (used interchangeably herein without the intent to limit) of an orthopedic implant such as a knee prosthesis onto a patient's knee. For example, in connection with a total knee replacement, the orthopedic implant (e.g., knee prosthesis) may include a femoral implant and a tibial implant. In use, the femoral implant is attached to the patient's femur while the tibial implant is attached to the patient's tibia. Generally speaking, the femoral and tibial implants may each include a support member (e.g., an intramedullary stem), which is attachable to an articular component, a tray, a load bearing component, etc. (terms used interchangeably herein without the intent to limit). In use, the support member is arranged and configured to be inserted within an intramedullary canal of the patient's bone while the tray mounts upon a prepared surface on the patient's bone. A bearing member or insert is typically mounted upon the tray of the tibial implant.

There are several factors that are potentially relevant to the design and performance of orthopedic implants. For example, in connection with an orthopedic tibial implant, a non-exhaustive list of such factors includes the implant's flexibility (or the flexibility of certain portions of the implant or its flexibility about certain axes or other constructs), which may indicate the degree to which the tray conforms to the potentially uneven resected surfaces of a proximal tibia; the implant's rigidity (or the rigidity of certain portions of the implant or its rigidity about certain axes or other constructs), which may indicate the degree to which stresses or other forces imposed by the bone and other anatomy associated with the knee joint are transmitted to the peripheral hard cortical shell of the proximal tibia; the implant's resistance to rotation; the amount of bone preserved; and/or other potentially relevant factors. In some instances, accommodation of these or other factors may require tradeoffs to balance competing factors. In some instances, one or more of these factors may not be considered or given a high level of importance to the design of an orthopedic implant.

One known knee prosthesis is Journey II manufactured and distributed by Smith Nephew, Inc. In use, the Journey II knee prosthesis attempts to substantially mimic the kinematics of the patient's natural knee. Specifically, for example, the Journey II knee prosthesis includes a convex lateral side that substantially mimics the convex lateral side of a natural tibia. As a result, the patient's femur is permitted to lock forward in a screw home position, which mimics the screw home position of the natural knee. One consequence of mimicking the natural screw home position is that the tibial implant of the knee prosthesis experiences loading anteriorly on the tibial tray.

It is with this in mind that the present disclosure is provided. Examples of prior art disclosing tibial implants are <CIT> Al and <CIT>.

The disclosed tibial implant comprises a tibial tray and a support member, the tibial tray including a top surface and a bottom surface, the support member extending from the bottom surface of the tibial tray, the support member being arranged and configured to be at least partially positioned within an intramedullary canal of a patient's bone for coupling the tibial implant to the patient's bone during use. The support member including a stem portion and one or more keels extending from the stem portion. The support member may further comprise one or more pegs positioned anteriorly on the bottom surface of the tibial tray, and one or more bridge members coupling the one or more pegs to the one or more keels, respectively, the one or more bridge members arranged and configured to transfer loads from the one or more pegs to the one or more keels.

The tibial implant further comprises a chamfer loading zone between the bottom surface of the tibial tray and the support member, the chamfer loading zone providing a variable thickness transition area between the bottom surface of the tibial tray and the support member to transfer loads between the tibial tray and the support member. The chamfer loading zone is positioned between a radiused surface associated with the support member and the bottom surface of the tibial tray.

In one embodiment, the one or more keels includes first and second keels, the one or more pegs include first and second pegs, and the one or more bridge members include first and second bridge members, the first peg being coupled to the first keel via the first bridge member, the second peg being coupled to the second keel via the second bridge member.

In one embodiment, the first keel extends from the medial side of the stem portion toward the medial side of the tibial tray, the second keel extends from the lateral side of the stem portion toward the lateral side of the tibial tray.

In one embodiment, the first and second keels extend posteriorly from the stem portion.

In one embodiment, the first and second pegs are positioned closer to a periphery edge of the tibial tray as compared to the stem portion.

In one embodiment, the first and second pegs are positioned anteriorly as compared to the stem portion.

In one embodiment, the tibial tray and the support member including the stem portion, the one or more keels, the one or more pegs, and the one or more bridge members are monolithically or integrally formed.

In one embodiment, the bottom surface of the tibial tray further comprises a porous layer mounted thereon.

In one embodiment, the support member includes one or more protrusions coupled to the stem portion, the one or more protrusions extending along a longitudinal length of the stem portion.

In one embodiment, the support member includes one or more protrusions coupled to the one or more keels, the one or more protrusions extending along a longitudinal length of the keels.

In one embodiment, each of the stem portion, the one or more keels, the one or more pegs, and the one or more bridge members includes a chamfer loading zone extending therefrom.

In one embodiment, the chamfer loading zone is arranged and configured to provide the tibial tray with a variable thickness to transition the bottom surface of the tibial tray to the support member while an overall combined thickness of the tibial tray and a porous coating applied thereon remains constant.

In one embodiment, each of the chamfer loading zones includes a circular shape extending outwardly from the support member.

The tibial implant comprises a tibial tray and a support member, the tibial tray including a top surface and a bottom surface, the support member extending from the bottom surface, the support member being arranged and configured to be at least partially positioned within an intramedullary canal of a patient's bone for coupling the implant to the patient's bone during use. The tibial implant further comprising a chamfer loading zone between the bottom surface of the tibial tray and the support member, the chamfer loading zone providing a variable thickness transition area between the bottom surface of the tibial tray and the support member to guide distribution of a load between the tibial tray and the support member. The chamfer loading zone is positioned between a radiused surface associated with the support member and the bottom surface of the tibial tray.

In one embodiment, the support member includes a stem portion, one or more keels extending from the stem portion, and one or more pegs positioned anteriorly on the bottom surface of the tibial tray, each of the stem portion, the one or more keels, and the one or more pegs, includes a chamfer loading zone extending therefrom.

In one embodiment, each of the chamfer loading zones includes a circular shape extending outwardly from the stem portion, the one or more keels, and the one or more pegs.

In one embodiment, the chamfer loading zone is arranged and configured to provide the tibial tray with a variable thickness to transition the bottom surface of the tibial tray to the support member while an overall combined thickness of the tibial tray and a porous coating applied thereon remain constant.

In one embodiment, the one or more pegs are coupled to the one or more keels, respectively, via one or more bridge members, respectively, so that anterior loading on the pegs is transferred to the keels via the bridge members.

In one embodiment, at least a portion of the porous layer comprises a non-faceted bottom surface arranged and configured to provide a variable thickness transition area between the bottom surface of the tibial tray and the support member to guide distribution of a load between the tibial tray and the support member.

In an alternate embodiment, a tibial implant is disclosed. The tibial implant comprising a tibial tray and a support member, the tibial tray including a top surface and a bottom surface, the support member extending from the bottom surface, the support member being arranged and configured to be at least partially positioned within an intramedullary canal of a patient's bone for coupling the tibial implant to the patient's bone during use. The tibial tray further comprising a porous surface including a non-faceted bottom surface. In one embodiment, the non-faceted bottom surface of the porous surface conceals chamfer loading zones arranged and configured to provide a variable thickness transition area between the bottom surface of the tibial tray and the support member to guide distribution of a load between the tibial tray and the support member.

In one embodiment, the non-faceted porous structure nests into a precision prepared proximal tibia. The proximal tibia is prepared with precision milling via, for example, a bur. Strategic chamfer zones and added material may be embedded within the non-faceted porous structure to provide optimal support for in vivo loading.

Embodiments of the present disclosure provide numerous advantages. For example, by providing bridge members between the pegs and the keels, the tibial implant is better able to handle and distribute loads experience by an anterior portion of the tibial tray. Similarly, by incorporating chamfer loading zones between the tibial tray and the support member, the tibial implant is better able to distribute loads experienced during use while minimizing the overall thickness of the tibial tray.

Further features and advantages of at least some of the embodiments of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.

By way of example, a specific embodiment of the disclosed device will now be described, with reference to the accompanying drawings, in which:.

The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict example embodiments of the disclosure, and therefore are not be considered as limiting in scope. In the drawings, like numbering represents like elements.

Various features or the like of an orthopedic implant such as a knee prosthesis (e.g., a tibial implant or component) will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more features of the knee prosthesis will be shown and described. It should be appreciated that the various features or the like may be used independently of, or in combination, with each other. It will be appreciated that a knee prosthesis as disclosed herein may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain features of the knee prosthesis to those skilled in the art. In the drawings, like numbers refer to like elements throughout unless otherwise noted.

As will be described herein, in accordance with one or more features of the present disclosure, a tibial implant is disclosed. In one embodiment, the tibial implant includes a tibial tray and a support member including an intramedullary stem arranged and configured for implantation into an intramedullary canal of a patient's bone such as, for example, the patient's tibia. In addition, in accordance with one feature of the present disclosure, the tibial tray may further include one or more pegs positioned anteriorly on a bottom surface of the tray and one or more bridges for coupling the pegs to the support member so that loads received by the pegs are transferred to the support member. In addition, the tibial implant includes a chamfer loading zone for elongating the transition area between the support member and the bottom surface of the tibial tray to extend the area over which the load is transferred.

Referring to <FIG>, an example not forming part of the invention of a tibial implant <NUM> is illustrated. <FIG> and <FIG> illustrate a bottom view of the tibial implant <NUM> with a porous layer <NUM> coupled thereto or mounted thereon. <FIG> and <FIG> illustrate a bottom view of the tibial implant <NUM> with the porous layer <NUM> removed.

As shown, the tibial implant <NUM> includes a tibial tray <NUM> connected to a support member <NUM>. The support member <NUM> can be connected to the tibial tray <NUM> by any technique now known or hereafter developed including, for example, a threaded connection, a press-fit, an adhesive, cement, or other techniques. In one example, the support member <NUM> is monolithic or integrally formed with the tibial tray <NUM>. For example, the tibial tray <NUM> and the support member <NUM> may be monolithically or integrally formed using any now known or hereafter developed technique or method including, for example, additive manufacturing techniques. For example, some non-limiting additive manufacturing techniques include selective laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), three-dimensional printing, or the like.

As illustrated, the tibial tray includes a top or superior surface <NUM> and a bottom or inferior surface <NUM>. As illustrated in <FIG> and <FIG>, the bottom surface <NUM> of the tibial tray <NUM> includes a porous layer or coating <NUM> applied thereto. For example, the porous coating or layer <NUM> is a titanium layer that may be applied to the bottom surface <NUM> of the tibial tray <NUM>. The porous coating or layer <NUM> may be applied to the bottom surface <NUM> of the tibial tray <NUM> by any now known or hereafter developed technique or method. For example, the porous coating or layer <NUM> may be applied to the bottom surface <NUM> of the tibial tray <NUM> via an additive manufacturing technique. For example, some non-limiting additive manufacturing techniques include selective laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), three-dimensional printing, or the like.

In use, the top surface <NUM> of the tibial tray <NUM> may include a lip or lock (not shown) for receiving and/or securing one or more inserts (not shown) to the tibial tray <NUM>, such inserts may be designed to contact and articulate with a femoral orthopedic implant (not shown) in use. Alternatively, the tibial tray <NUM> itself may include articular surfaces that do not require separate articular inserts. In one example, as shown, the tibial tray <NUM> may include a posterior notch <NUM>, which may be designed to allow preservation of the attachment site of a posterior cruciate ligament, although, in other embodiments, the tibial tray <NUM> may or may not include this or other notches or gaps for preserving one or both of the cruciate ligaments. In other words, the tibial tray <NUM>, in some embodiments, may be for use in a cruciate sacrificing procedure, a posterior cruciate preserving procedure, or a bi-cruciate preserving procedure. In some embodiments, the tibial tray <NUM> may be used for a mobile bearing knee joint or a fixed bearing knee joint. It will be appreciated that a variety of top surfaces and peripheral shapes are possible according to various embodiments and that such shapes can be influenced, at least in part, by strength requirements for the tray <NUM>.

As shown, the support member <NUM> extends from the bottom surface <NUM> of the tibial tray <NUM>. In use, the support member <NUM> is positioned, at least partially, within the intramedullary canal of the patient's tibia to couple the tibial implant <NUM> to the patient's tibia. In one embodiment, as shown, the support member <NUM> includes a stem portion <NUM> that extends away from the bottom surface <NUM> of the tibial tray <NUM> along a longitudinal axis L. In the illustrated embodiment, the longitudinal axis L is substantially perpendicular to the bottom surface <NUM> of the tibial tray <NUM> in the medial-lateral direction, but other angles may be used. Additionally, in some embodiments, the tibial tray <NUM> may include a slope in the anterior-posterior direction. For example, the tibial tray <NUM> can have a <NUM> to <NUM> degree posterior slope. Alternatively, the tibial tray <NUM> can have a zero degree slope. The stem portion <NUM> may be positioned offset from a center of the tibial tray <NUM> (e.g., positioned more medial than lateral). For example, in one embodiment, the stem portion <NUM> may be medialized slightly from the center of the tibial tray <NUM>. For example, the stem portion <NUM> can be medialized <NUM> to <NUM> from the center of the tibial tray <NUM>. In other embodiments, the stem portion <NUM> may be centered on the tibial tray <NUM>.

In some embodiments, the stem portion <NUM> may include a first portion <NUM> adjacent to the bottom surface <NUM> of the tibial tray <NUM> and a second portion <NUM> that extends away from the first portion <NUM>. The first portion <NUM> may have a first cross sectional area and the second portion <NUM> may have a second cross sectional area wherein the first cross sectional area is larger than the second cross sectional area. In other embodiments, the second portion <NUM> can have the same cross sectional area and shape as the first portion <NUM>. In use, the stem portion <NUM> has a length that is sized to promote varus-valgus stability and resistance of the tibial tray <NUM> to liftoff from the patient's bone.

In one embodiment, as shown, the support member <NUM> may include one or more fins <NUM> spaced about the stem portion <NUM>. For example, as illustrated, the stem portion <NUM> may include four fins <NUM> spaced thereabout, although this is but one configuration and more or less fins <NUM> may be used. Moreover, in one embodiment, the fins <NUM> can be spaced equally from each other or in another arrangement as desired. In one embodiment, the fins <NUM> may extend along the support member <NUM> towards the second portion <NUM> in a tapering configuration. In use, the fins <NUM> assist in providing rotational stability and help with implantation and alignment of the tibial tray <NUM> in bone upon implantation. Any or all of the fins <NUM> can also be sized to a maximum that is implantable based on the anatomy of the patient.

In addition, as shown, the support member <NUM> may also include one or more posterior keels or arms <NUM> (terms used interchangeably herein without the intent to limit). As shown, the support member <NUM> may include first and second posterior keels 170a, 170b mounted on the bottom surface <NUM> of the tibial tray <NUM> extending from either side of the stem portion <NUM> posteriorly towards the posterior side P of the tibial tray <NUM>, although this is just one configuration and more or less keels <NUM> and/or different configurations of keels <NUM> may be utilized. In use, the keels <NUM> may increase the strength of the implant <NUM> while also helping to prevent rotation of the tibial implant <NUM> relative to the patient's bone (e.g., keels <NUM> assist with rotational stability of the tibial tray <NUM> in bone upon implantation).

As illustrated, in one embodiment, the first keel 170a may be angled relative to the second keel 170b, but in other embodiments the first and second keels 170a, 170b may be substantially aligned with one another. In one embodiment, the first and second keels 170a, 170b may be separated from each other via an angle ranging from about <NUM> degrees to about <NUM> degrees. As illustrated, in one embodiment, the first and second keels 170a, 170b may have a similar shape and size, however, in other embodiments, the first and second keels 170a, 170b may be provided with different shapes and sizes. In one embodiment, the first and second keels 170a, 170b curve or curl towards the medial M and lateral L sides, respectively, of the tray <NUM>.

The first and second keels 170a, 170b extend longitudinally along the support member <NUM> towards the second portion <NUM>; however, as illustrated, the first and second keels 170a, 170b may be shorter or smaller than the fins <NUM> and, as such, do not extend as far longitudinally as the fins <NUM> along the support member <NUM>. Each of the first and second keels 170a, 170b may have a horizontal length that extends towards a rim or periphery edge <NUM> of the tibial tray <NUM>. The first and second keels 170a, 170b may each have a sharp edge.

As illustrated, the first and second keels 170a, 170b, as well as other components of the support member <NUM>, may include a plurality of rail protrusions or ridges <NUM> (terms used interchangeably herein without the intent to limit) that extend along the height or a portion of the keels <NUM> as measured along the longitudinal axis L. In one embodiment, the plurality of ridges <NUM> may have a square or semi square cross sectional shape however in other forms the shape may be rectangular or semicircular. The plurality of ridges <NUM> can have a variable height and a variable width such that one or more of the plurality of ridges <NUM> has a unique height and width. For example, in some forms, the height and width of the plurality of ridges <NUM> can range between <NUM> and <NUM> millimeters. The plurality of ridges <NUM> can be spaced along the keels <NUM> in a uniform spacing arrangement or non-uniform spacing arrangement. The plurality of ridges <NUM> assist with added bone compression and fixation strength of the tibial implant <NUM> in the patient's bone.

Beneficially, the fins <NUM> and the keels <NUM> provide increased rotational resistance and strength for the tibial implant <NUM> when implanted. The configuration of the support member <NUM> including the stem portion <NUM>, fins, <NUM>, and keels <NUM> provide improved fixation between the tibial tray <NUM> and the patient's bone post-operatively. Moreover, the fins <NUM> positioned on the anterior side A of the tibial tray <NUM> are more sensitive to anatomic dimensions of the patient's bone than the fins <NUM> positioned on the posterior side P therefore the size, location, and position of the anterior fins <NUM> on the tibial tray <NUM> are more sensitive than the posterior fins <NUM>.

In addition, as illustrated, in one example of an embodiment, the tibial tray <NUM> may also include one or more pegs <NUM>. For example, as shown, the tibial implant <NUM> may include first and second pegs 180a, 180b, although this is but one configuration and more or less pegs may be used. As illustrated, the first and second pegs 180a, 180b may be mounted on the bottom surface <NUM> of the tibial tray <NUM>. The pegs <NUM> can be connected to the tibial tray <NUM> by any technique now known or hereafter developed including, for example, threaded connection, press-fit, adhesive, cement, or other techniques. In one embodiment, the pegs <NUM> are monolithic or integrally formed with the tibial tray <NUM>.

In one embodiment, as illustrated, the first and second pegs 180a, 180b are positioned near the rim or periphery edge <NUM> of the tibial tray <NUM>. The first and second pegs 180a, 180b approach the tibial plateau for added stability of the tibial tray <NUM>, and enter into denser bone than in the central canal upon implantation. Additional pegs <NUM> can be mounted as desired. The pegs <NUM> can have any suitable size and shape arranged and configured to engage the patient's bone to provide increased stability. For example, as shown, the pegs <NUM> may be substantially cylindrical with a pointed tip, although other shapes are envisioned such as, for example, an arrowhead shape.

In accordance with one or more features of the present disclosure, in use, the pegs <NUM> such as, for example, the first and second pegs 180a, 180b may be coupled to the support member <NUM> such as, for example, to the first and second keels 170a, 170b, respectively, via a support rib, bridge or bridge member, radius, material, or the like <NUM> (terms used interchangeably herein without the intent to limit). As illustrated, in one embodiment, during use, the bridge <NUM> is arranged and configured to couple the first and second pegs 180a, 180b to the first and second keels 170a, 170b, respectively, so that any loads received by the first and second pegs 180a, 180b can be transferred to the support member <NUM> via the first and second keels 170a, 170b. Thus arranged, any anterior load can be carried back from the pegs <NUM>, which are positioned anteriorly on the tray <NUM> to capture the anterior loads, to the keels <NUM> and subsequently to the support member <NUM> thereby providing the tibial tray <NUM> with increased strength to avoid breakage due to an associated anterior loading condition. That is, in contrast with known implants, by coupling the pegs <NUM> to the support member <NUM> via, for example, the keels <NUM>, the anterior load is transferred from the pegs <NUM> to the keels <NUM> and to the stem portion <NUM> of the support member <NUM> instead of to the tray <NUM> thereby providing increased strength to avoid damage such as breakage of the tray.

In use, the bridge <NUM> may have any configuration now known or hereafter developed arranged and configured to transfer the load from the pegs <NUM> to the keels <NUM> to the stem portion <NUM> of the support member <NUM>. That is, the bridge <NUM> may have any configuration arranged to protect the anterior loading area and to carry the stress back to the support member <NUM>. For example, as shown, the bridge <NUM> may be manufactured from wrought material and be monolithically or integrally formed with the tray <NUM> and/or support member <NUM>. Alternatively, it is envisioned that the bridges may include, for example, an open space (e.g., window), which could be filled with a lattice and/or porous structure. Alternatively, the bridges may incorporate a reduced cross sectional area, or be connected with struts.

While the pegs <NUM> and the bridges190 have been shown and illustrated with a particular tibial tray and support member, it should be understood that the present disclosure is not so limited and that the pegs <NUM> and bridges <NUM> may be used with any tibial implant now known or hereafter developed unless specifically claimed.

Referring to <FIG> and <FIG>, in accordance with one or more features of the present disclosure that may be used in combination with the pegs <NUM> and bridges <NUM> disclosed above or separately therefrom, the tibial tray <NUM> includes a chamfer loading zone <NUM> formed in the bottom or inferior surface <NUM> thereof. In addition, as illustrated in <FIG> and <FIG>, the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> includes a radiused surface <NUM> at the connection or formation to the bottom surface <NUM> of the tibial tray <NUM>. In use, the radiused surface <NUM> facilitates transferring load between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the tray <NUM> by preventing, or at least minimizing stress concentrations (e.g., the radiused surfaces <NUM> help to facilitate better load transfer back towards the support member). As illustrated, and in connection with one or more features of the present disclosure, the bottom surface <NUM> of the tray <NUM> also includes one or more chamfers <NUM> formed between the radiused surface <NUM> and the bottom surface <NUM> of the tibial tray <NUM>. Referring to <FIG>, which illustrates an example of an embodiment of a cross-sectional area of a tray <NUM> utilizing one or more chamfers <NUM>, the chamfers <NUM> elongate the loading zone to increase the area over which the load is transferred between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the tray <NUM>. In use, the chamfer loading zones <NUM> act to provide a variable thickness to guide transfer of the load between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the tray <NUM>. That is, the chamfer loading zones <NUM> act to increase the thickness of the tibial tray <NUM> adjacent to the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM>. At the same time, the chamfer loading zones <NUM> facilitate maintaining a constant overall combined thickness of the tibial component (e.g., combined thickness of the tibial tray <NUM> and the porous layer <NUM>). That is, the chamfer loading zones <NUM> enable the thickness of the tray <NUM> to be increased while the overall combined thickness of the tibial component remains constant across the surface area of the tibial component (e.g., during application of the porous layer <NUM>, the thickness of the porous layer <NUM> can be minimized over the chamfer loading zones <NUM> so that the overall combined thickness of the tibial component (e.g., combined thickness of the tray and the porous layer) remains constant).

In use, the chamfer loading zones <NUM> may have any size and shape arranged and configured to facilitate transfer of the load between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the tray <NUM>. As illustrated, in one embodiment, the chamfer loading zone <NUM> may have a substantially circular shape extending from and about the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM>. As shown, in one embodiment, adjacent chamfer loading zones <NUM> may blend, overlap with, etc. each other. In use, the chamfer loading zones <NUM> transition from a first height adjacent to the radiused surface <NUM> to a second height extending away from the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM>, the first height being larger than the second height. In one embodiment, the height of the chamfer loading zones <NUM> may extend or taper from approximately <NUM> to approximately <NUM>, preferably in one embodiment, the height of the chamfer loading zones <NUM> may extend from approximately <NUM> to approximately <NUM>,<NUM>. Additionally, in one embodiment, the chamfer loading zones <NUM> may extend or taper outwardly over a length of approximately <NUM> to approximately <NUM> plus, preferably in one embodiment the chamfer loading zones <NUM> may extend or taper outwardly over a length of approximately <NUM> to approximately <NUM>,<NUM> (e.g., the outward extent of the chamfer loading zones <NUM> only being limited by the overall size of the implant).

Alternatively, referring to <FIG>, in an alternate example of an embodiment, the chamfer loading zone <NUM> can be blended into (e.g., combined) with the radiused surface <NUM> transitioning between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the bottom surface <NUM> of the tray <NUM>. Thus arranged, the chamfer loading zone <NUM> includes an increased thickness that is blended in with the radii.

Alternatively, referring to <FIG>, in an alternate example of an embodiment, the bridge <NUM> and the chamfer loading zone <NUM> may be blended together to create a reduced profile transition between the pegs <NUM> and the support member <NUM> (e.g., keels <NUM>). In this manner, the bridge <NUM> is substantially hidden from view when the porous layer is applied.

Alternatively, referring to <FIG>, in an alternate example of an embodiment, the bridge <NUM> may be provided in the form of a rail <NUM> between and coupling adjacent keels <NUM>. That is, as illustrated, the pegs <NUM> may be positioned on the rail <NUM>, which extends between adjacent keels <NUM>.

Referring to <FIG>, an example not forming part of the invention of a tibial implant <NUM> is illustrated. In use, the tibial implant <NUM> is substantially similar to the previous embodiments described herein. As such, for the sake of brevity, discussion of some components is omitted herefrom.

<FIG> illustrate various views of the tibial implant <NUM>. <FIG> illustrates a perspective view of a patient's tibial, the patient's tibial being prepared to receive the tibial implant <NUM> shown in <FIG>. Referring to <FIG>, the tibial implant <NUM> is illustrated with the porous layer <NUM> coupled thereto or mounted thereon.

Similar to the embodiments previously described herein, the tibial implant <NUM> includes a tibial tray <NUM> connected to a support member <NUM>. In addition, the tibial tray includes a top or superior surface <NUM> and a bottom or inferior surface <NUM>. As previously mentioned, and as illustrated, the bottom surface <NUM> of the tibial tray <NUM> includes a porous layer or coating <NUM> applied thereto.

Similar to the embodiments previously described herein, the support member <NUM> extends from the bottom surface <NUM> of the tibial tray <NUM>. In use, the support member <NUM> is positioned, at least partially, within the intramedullary canal of the patient's tibia T (<FIG>) to couple the tibial implant <NUM> to the patient's tibia T. The support member <NUM> includes a stem portion <NUM> that extends away from the bottom surface <NUM> of the tibial tray <NUM> along a longitudinal axis L. The longitudinal axis L may be substantially perpendicular to the bottom surface <NUM> of the tibial tray <NUM> in the medial-lateral direction. The stem portion <NUM> may be positioned offset from a center of the tibial tray <NUM> (e.g., positioned more medial than lateral). For example, in one example, the stem portion <NUM> may be medialized slightly from the center of the tibial tray <NUM>. The tibial tray <NUM> may include a slope in the anterior-posterior direction. In some examples, the stem portion <NUM> may include a first portion <NUM> adjacent to the bottom surface <NUM> of the tibial tray <NUM> and a second portion <NUM> that extends away from the first portion <NUM>. The first portion <NUM> may have a first cross sectional area and the second portion <NUM> may have a second cross sectional area wherein the first cross sectional area is larger than the second cross sectional area. In other examples the second portion <NUM> can have the same cross sectional area and shape as the first portion <NUM>. In use, the stem portion <NUM> has a length that is sized to promote varus-valgus stability and resistance of the tibial tray <NUM> to liftoff from the patient's bone.

In addition, in one example, as previously mentioned and as shown, the support member <NUM> may include one or more fins <NUM> spaced about the stem portion <NUM>. In use, the fins <NUM> assist in providing rotational stability and help with implantation and alignment of the tibial tray <NUM> in bone upon implantation. Any or all of the fins <NUM> can also be sized to a maximum that is implantable based on the anatomy of the patient.

In addition, as previously mentioned and as shown, the support member <NUM> may also include one or more posterior keels <NUM>. As shown, the support member <NUM> may include first and second posterior keels 170a, 170b mounted on the bottom surface <NUM> of the tibial tray <NUM> extending from either side of the stem portion <NUM> posteriorly towards the posterior side P of the tibial tray <NUM>, although this is just one configuration and more or less keels <NUM> and/or different configurations of keels <NUM> may be utilized. In use, the keels <NUM> may increase the strength of the implant <NUM> while also helping to prevent rotation of the tibial implant <NUM> relative to the patient's bone (e.g., keels <NUM> assist with rotational stability of the tibial tray <NUM> in bone upon implantation).

In use, and as previously described, the first and second keels 170a, 170b, as well as other components of the support member <NUM>, may include a plurality of ridges <NUM> that extend along the height or a portion of the keels <NUM> as measured along the longitudinal axis L. In one example, the plurality of ridges <NUM> may have a square or semi square cross sectional shape however in other forms the shape may be rectangular or semicircular. In use, the plurality of ridges <NUM> assist with added bone compression and fixation strength of the tibial implant <NUM> in the patient's bone.

In addition, as illustrated, in one example, the tibial tray <NUM> may also include one or more pegs <NUM>. For example, as shown, the tibial implant <NUM> may include first and second pegs 180a, 180b, although this is but one configuration and more or less pegs may be used. As illustrated, the first and second pegs 180a, 180b may be mounted on the bottom surface <NUM> of the tibial tray <NUM>. In one example, as illustrated, the first and second pegs 180a, 180b may be positioned closer to the rim or periphery edge <NUM> of the tibial tray <NUM>. The first and second pegs 180a, 180b approach the tibial plateau for added stability of the tibial tray <NUM>, and enter into denser bone than in the central canal upon implantation. Additional pegs <NUM> can be mounted as desired. The pegs <NUM> can have any suitable size and shape arranged and configured to engage the patient's bone to provide increased stability. For example, as shown, the pegs <NUM> may be substantially cylindrical with a pointed tip, although other shapes are envisioned such as, for example, an arrowhead shape.

As previously mentioned, and illustrated, in accordance with one or more features of the present disclosure, in use, the pegs <NUM> such as, for example, the first and second pegs 180a, 180b may be coupled to the support member <NUM> such as, for example, to the first and second keels 170a, 170b, respectively, via a bridge <NUM> (<FIG>). In use, the bridge <NUM> is arranged and configured to couple the first and second pegs 180a, 180b to the first and second keels 170a, 170b, respectively, so that any loads received by the first and second pegs 180a, 180b can be transferred to the support member <NUM> via the first and second keels 170a, 170b. Thus arranged, any anterior load can be carried back from the pegs <NUM>, which are positioned anteriorly on the tray <NUM> to capture the anterior loads, to the keels <NUM> and subsequently to the support member <NUM> thereby providing the tibial tray <NUM> with increased strength to avoid breakage due to an associated anterior loading condition. That is, in contrast with known implants, by coupling the pegs <NUM> to the support member <NUM> via, for example, the keels <NUM>, the anterior load is transferred from the pegs <NUM> to the keels <NUM> and to the stem portion <NUM> of the support member <NUM> instead of to the tray <NUM> thereby providing increased strength to avoid damage such as breakage of the tray.

In addition, and as previously mentioned, in accordance with one or more features of the present disclosure that may be used in combination with the pegs <NUM> and bridges <NUM> disclosed above or separately therefrom, the tibial tray <NUM> includes a chamfer loading zone <NUM> (<FIG> and <FIG>) formed in the bottom or inferior surface <NUM> thereof. In addition, the support member <NUM> including the stem portion <NUM>, keels <NUM>, and optionally pegs <NUM> and bridges <NUM>, includes a radiused surface <NUM> at the connection or formation to the bottom surface <NUM> of the tibial tray <NUM>. In use, the radiused surface <NUM> facilitates transferring load between the support member <NUM> including the stem portion <NUM>, keels <NUM>, and optionally pegs <NUM> and bridges <NUM> and the tray <NUM> by preventing, or at least minimizing stress concentrations (e.g., the radiused surfaces <NUM> help to facilitate better load transfer back towards the support member). The chamfer loading zone <NUM> may be formed between the radiused surface <NUM> and the bottom surface <NUM> of the tibial tray <NUM>.

In use, the chamfer loading zones <NUM> act to provide a variable thickness to guide transfer of the load between the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM> and the tray <NUM>. That is, the chamfer loading zones <NUM> act to increase the thickness of the tibial tray <NUM> adjacent to the support member <NUM> including the stem portion <NUM>, keels <NUM>, pegs <NUM>, and bridges <NUM>.

Referring to <FIG>, in accordance with one or more features of the present disclosure, the porous coating <NUM> may be include a non-faceted bottom surface <NUM> (e.g., a non-planar surface). In one embodiment, as illustrated, the porous coating <NUM> may include a planar surface along an interior region or area of the tibial tray <NUM> adjacent to the support member <NUM>, the non-faceted bottom surface <NUM> may be provided adjacent to the periphery surface <NUM> of the tibial tray <NUM>.

In use, the non-faceted bottom surface <NUM> of the porous coating <NUM> may be arranged and configured to conceal, for example, one or more bridges <NUM>, chamfers loading zones <NUM>, and/or radiused surfaces <NUM>. In addition, the non-faceted bottom surface <NUM> of the porous coating <NUM> may be arranged and configured to provide the tibial tray <NUM> with an increased thickness adjacent to the support member <NUM>. In one embodiment, the non-faceted bottom surface may commence a distance from the periphery surface <NUM> of the tibial tray <NUM> and may provide a radiused or transitioned area or surface <NUM> arranged and configured along a periphery of the non-faceted bottom surface <NUM>, the radiused or transitioned area or surface <NUM> arranged and configured to transition from the non-faceted bottom surface <NUM> to the tibial tray <NUM>. Thus arranged, the tibial tray <NUM> includes an area of increased thickness (e.g., non-faceted bottom surface <NUM> ) that is blended in with the trial tray <NUM> via a radiused or transitioned area or surface <NUM> (e.g., a radiused transition is provided between the non-faceted bottom surface <NUM> and the tibial tray <NUM>) to guide distribution of a load between the support member <NUM> and the tibial tray <NUM>.

In use, as illustrated in <FIG>, the non-faceted bottom surface <NUM> of the tibial tray <NUM> is arranged and configured to be positioned within or nest into a precision prepared proximal tibia T of the patient. In use, the patient's proximal tibia T may be prepared using precision milling via, for example, a bur associated with a robotic surgical system, although any other mechanisms for preparing the patient's proximal tibial T may be used.

As previously mentioned herein, the tibial implant can be manufactured from any suitable bio-compatible material now known or hereafter developed used to manufacture orthopedic implants including, for example, titanium, cobalt chrome, stainless steel, ceramic or other biocompatible material. In addition, and/or alternatively, the tibial implant may be formed using any desired or appropriate methodologies or technologies now known or hereafter developed. For example, in one embodiment, the tibial implant may be manufactured using any now known or hereafter developed additive manufacturing technique. By way of some, non-limiting known techniques, the tibial implant could be manufactured from selective laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), three-dimensional printing, or the like. For instance, in some embodiments, the entire tibial implant may be formed as a monolithic or integral implant (including any porous or other in-growth promoting surfaces or materials). In some embodiments, portions of the tibial implant may be formed and then additional in-growth materials, surfaces, and/or treatments could be added or applied to the implant. In other embodiments, an additive manufacturing technique such as, for example, electron beam melting methods or methods that use lasers to subtract or remove select portions of material from an initially solid material may be used. In other embodiments, portions or all of the tibial implant can be formed using casting or other technologies or methods. In some embodiments, a non-porous implant such as a tibial implant may be formed using an additive manufacturing technique such as, for example, SLS technologies and subsequently that implant may be subjected to acid etching, grit blasting, plasma spraying (e.g. of titanium oxide or another metal to promote in-growth) or other treatments.

In use, the tibial implant may be part of a set of tibial implants of various standard sizes, or may be a patient-matched tibial implant with certain geometries and/or other features of the implant customized for a particular patient's anatomy.

Claim 1:
A tibial implant (<NUM>) comprising:
a tibial tray (<NUM>) including a top surface (<NUM>) and a bottom surface (<NUM>); and
a support member (<NUM>) extending from the bottom surface of the tibial tray, the support member being arranged and configured to be at least partially positioned within an intramedullary canal of a patient's bone for coupling the tibial implant to the patient's bone during use, the support member including:
a stem portion (<NUM>): and
one or more keels (<NUM>) extending from the stem portion;
wherein the tibial implant further comprises a chamfer loading zone (<NUM>) between the bottom surface of the tibial tray and the support member, the chamfer loading zone providing a variable thickness transition area between the bottom surface of the tibial tray and the support member to transfer loads between the tibial tray and the support member,
characterized in that the chamfer loading zone is positioned between a radiused surface (<NUM>) associated with the support member and the bottom surface of the tibial tray.