Patent Description:
Currently available implants for total ankle replacement may experience loosening of the tibial component. In addition, some currently available implants for total ankle replacement may cause stress concentrations in the medial malleolus. In other currently available implants for total ankle replacement, the sizing of the talus component lacks proper bone coverage. Finally, some currently available implants for total ankle replacement lack vertical stabilization features on the tibia.

Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and/or disadvantages of the currently used implants. For example, in view of the deficiencies of the current implants, it would be desirable to develop implants, devices, and/or systems which avoid loosening of the tibial component, remove the stress concentration from the medial malleolus, provide proper coverage of the talus bone, and provide features for vertical stabilization of the tibia.

<CIT> relates to systems and methods for replacement of an ankle by a prosthesis.

<CIT> relates to systems and instrumentalities for use in removal of tibial prostheses of total ankle replacements, and, in particular, to systems and instrumentalities for removing a tibial prosthesis having an intramedullary stem.

<CIT> relates to an ankle joint prosthesis.

The present disclosure is directed toward implants and devices for use in maintaining, correcting and/or resurfacing joint surfaces.

An implant according to the invention is defined in claim <NUM>, the implant including a first member, a second member comprising: a talus component comprising; a first end opposite a second end; a first side opposite a second; and a top surface opposite a bottom surface, the top surface comprising: a medial articulating surface extending from the first side toward the second side of the second member, wherein the medial articulating surface has at least one first curvature along a longitudinal axis and at least one second curvature perpendicular to the longitudinal axis; a lateral articulating surface extending from the second side of the second member toward the first side, wherein the lateral articulating surface has at least one third curvature along the longitudinal axis and at least one fourth curvature perpendicular to the longitudinal axis; wherein the medial articulating surface includes an anterior-medial sagittal radius and a posterior-medial sagittal radius; wherein the lateral articulating surface includes an anterior-lateral sagittal radius and a posterior-lateral sagittal radius; and wherein the anterior-lateral sagittal radius is larger than the anterior-medial sagittal radius and the posterior-medial sagittal radius is larger than the posterior-lateral sagittal radius, and an insert with a top surface and a bottom surface, wherein the top surface couples to the first member and the bottom surface engages the second member.

Described is a method for using the implant. The method includes obtaining an implant. The implant includes a first member, a second member, and an insert with a top surface and a bottom surface. The top surface of the insert couples to the first member and the bottom surface of the insert engages the second member. The method also includes making an incision to expose a joint with a first bone and a second bone and preparing the bones for receiving the implant. The method further includes coupling the first member to the first bone and the second member to the second bone. In addition, the method includes inserting a second end of the insert into a first end of the first member. Then, the method includes closing the incision.

Described is a kit. The kit including a plurality of first members of an implant, wherein the first members include a top surface and a bottom surface, a plurality of second members of the implant, wherein the second members include a top surface and a bottom surface, and a plurality of inserts of the implant, wherein the plurality of inserts include a top surface and a bottom surface. The top surface of each of the plurality of first members includes a radius and the radius is the same for each of the first members and the bottom surface of each of the plurality of second members has the same dimensions for each of the second members.

These and other objects, features and advantages of this disclosure will become apparent from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the detailed description herein, serve to explain the principles of the disclosure. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the disclosure.

Generally stated, disclosed herein are devices, systems, and methods for maintaining, correcting and/or resurfacing joint surfaces. Further, methods for using the implants, devices, and methods for maintaining, correcting and/or resurfacing joint surfaces are discussed.

In this detailed description and the following claims, the words proximal, distal, anterior or plantar, posterior or dorsal, medial, lateral, superior and inferior are defined by their standard usage for indicating a particular part or portion of a bone or implant according to the relative disposition of the natural bone or directional terms of reference. For example, "proximal" means the portion of a device or implant nearest the torso, while "distal" indicates the portion of the device or implant farthest from the torso. As for directional terms, "anterior" is a direction towards the front side of the body, "posterior" means a direction towards the back side of the body, "medial" means towards the midline of the body, "lateral" is a direction towards the sides or away from the midline of the body, "superior" means a direction above and "inferior" means a direction below another object or structure. Further, specifically in regards to the foot, the term "dorsal" refers to the top of the foot and the term "plantar" refers the bottom of the foot.

Similarly, positions or directions may be used herein with reference to anatomical structures or surfaces. For example, as the current devices, systems, instrumentation and methods are described herein with reference to use with the bones of the ankle, the bones of the foot, ankle and lower leg may be used to describe the surfaces, positions, directions or orientations of the devices, systems, instrumentation and methods. Further, the devices, systems, instrumentation and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to one side of the body for brevity purposes. However, as the human body is relatively symmetrical or mirrored about a line of symmetry (midline), it is hereby expressly contemplated that the devices, systems, instrumentation and methods, and the aspects, components, features and the like thereof, described and/or illustrated herein may be changed, varied, modified, reconfigured or otherwise altered for use or association with another side of the body for a same or similar purpose without departing from the scope of the disclosure. For example, the devices, systems, instrumentation and methods, and the aspects, components, features and the like thereof, described herein with respect to the right leg may be mirrored so that they likewise function with the left leg. Further, the devices, systems, instrumentation and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to the ankle for brevity purposes, but it should be understood that the devices, systems, instrumentation and methods may be used with other bones of the body having similar structures.

Referring to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference to <FIG>, there is illustrated an implant <NUM>. The implant <NUM> includes a first member or tibia base <NUM>, an insert <NUM>, and a second member, talus component, or articulating member <NUM>. The insert <NUM> includes a top surface <NUM> and a bottom surface <NUM>. The top surface <NUM> of the insert <NUM> couples to the first member <NUM> and the bottom surface <NUM> engages the second member <NUM>.

As shown in <FIG>, the first member <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The first member <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the first member <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The top surface <NUM> may include, for example, an arc shape or curvature extending between the first side <NUM> and the second side <NUM>, as shown in <FIG>, <FIG>. The curvature may have, for example, an arc radius ranging from approximately <NUM> to <NUM>. In an alternative embodiment, the top surface <NUM> of the first member <NUM> may be, for example, flat as the top surface <NUM> extends between the first side <NUM> and the second side <NUM>.

With continued reference to <FIG>, <FIG>, the top surface <NUM> of the first member <NUM> may also include, for example, sloped, tapered, or angled sides on the first side <NUM> and the second side <NUM> of the first member <NUM>. The angle of the sides of the top surface <NUM> at the first and second sides <NUM>, <NUM> may be, for example, approximately <NUM>° to <NUM>° from vertical and more specifically approximately <NUM>° from vertical. The edges of the first and second sides <NUM>, <NUM> of the first member <NUM> may be, for example, rounded or curved. The rounded edges may have, for example, a radii of approximately <NUM> to <NUM> and more specifically approximately <NUM> to <NUM>. The first member <NUM> may have an outer perimeter shape that may be, for example, a quadrilateral shape, such as, a generally trapezoidal shape from a top or bottom view, as shown in <FIG>, <FIG>, and <FIG>. The first and second sides <NUM>, <NUM> may be generally parallel and the first end <NUM> and second end <NUM> may be, for example, angled or curved as they extend from the first side <NUM> to the second side <NUM>. In an embodiment, the length of the first or medial side <NUM> may be, for example, shorter than the length of the second or lateral side <NUM>. The angle of the first end <NUM> may be, for example, smaller than the angle of the second end <NUM>. The top surface <NUM>, first side <NUM> and second side <NUM> may be, for example, textured or coated to provide a friction-stabilization surface and to allow for bone on-growth. The textured surface may be, for example, plasma sprayed biocompatible material, such as, commercially-pure titanium, or another biocompatible material as known by one of ordinary skill in the art.

With continued reference to <FIG>, the top surface <NUM> of the first member <NUM> includes at least one peg or vertical peg <NUM> extending away from the top surface <NUM>. The top surface <NUM> of the first member <NUM> also includes at least one protrusion, spike, pyramid, or cone <NUM> extending away from the top surface <NUM>. The at least one protrusion <NUM> may be, for example, spaced from the at least one peg <NUM>. The at least one protrusion <NUM> may be, for example, four protrusions <NUM>, although alternative numbers of protrusions <NUM> are also contemplated. The protrusions <NUM> may be, for example, positioned equally spaced around the at least one peg <NUM>. The at least one peg <NUM> and at least one protrusion <NUM> may not be, for example, textured, rather the at least one peg <NUM> and at least one protrusion <NUM> may be smooth to decrease bone resorption at the resection level.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the first member <NUM> is shown. The bottom surface <NUM> includes a recessed region or engagement region <NUM> extending into the first member <NUM> from the bottom surface <NUM> toward the top surface <NUM>. The first member <NUM> may come in multiple sizes for use with patient's having different size tibia bones and the recessed region <NUM> of each of the first members <NUM> will be, for example, sized and shaped the same to allow for replacement of the first member <NUM> as needed. The bottom surface <NUM> also includes an engagement channel <NUM> extending from the first end <NUM> into the recessed region <NUM>. In addition, the bottom surface <NUM> of the first member <NUM> includes a first engagement feature or first female dovetail portion <NUM> extending from the first side <NUM> into the recessed region <NUM>, a second engagement feature or second female dovetail portion <NUM> extending from the second side <NUM> into the recessed region <NUM>, and a third engagement feature or third female dovetail portion <NUM> extending from a position near the second end <NUM> into the recessed region <NUM>. The bottom surface <NUM> of the first member <NUM> also includes a slot or removal engagement feature <NUM> and a locking groove <NUM> positioned adjacent to the slot <NUM>. The slot <NUM> may be, for example, angled as the slot <NUM> extends from the first end <NUM> toward the locking groove <NUM>.

Referring now to <FIG>, the second member, talus component or articulating member <NUM> has a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The second member <NUM> also has a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the second member <NUM> has a top surface or articulating surface <NUM> opposite a bottom surface or bone engagement surface <NUM>. The second member <NUM> may have, for example, a trapezium shape, as shown in <FIG> and <FIG>. The first and second sides <NUM>, <NUM> may be, for example, angled as the sides <NUM>, <NUM> extend from the first end <NUM> to the second end <NUM>. The sides <NUM>, <NUM> may be angled, for example, approximately <NUM>° to <NUM>°, and more preferably approximately <NUM>°, as they extend away from the first end <NUM>. The first side <NUM> may be, for example, shorter than the second side <NUM>. The second member <NUM> includes an anterior recess <NUM> extending into the first end <NUM>. The anterior recess <NUM> may be, for example, positioned near a midpoint of a lateral axis of the second member <NUM> or, alternatively may be medially biased. The second member <NUM> also includes a posterior recess <NUM> extending into the second end <NUM>. The posterior recess <NUM> may be, for example, positioned near a midpoint of the lateral axis of the second member <NUM> or, alternatively may be medially biased.

As shown in <FIG> and <FIG>, the top surface <NUM> of the second member <NUM> includes a medial articulating surface <NUM> extending from the first side <NUM> of the second member <NUM> toward the second side <NUM>. The top surface <NUM> may also include a lateral articulating surface <NUM> extending from the second side <NUM> of the second member <NUM> toward the first side <NUM>. In addition, the top surface <NUM> also includes a central articulating portion <NUM> positioned at a point where the medial articulating surface <NUM> contacts the lateral articulating surface <NUM>. The medial articulating surface <NUM> may include at least one first curvature along a longitudinal axis and at least one second curvature perpendicular to the longitudinal axis, as shown in <FIG>. The lateral articulating surface <NUM> has at least one third curvature along the longitudinal axis and at least one fourth curvature perpendicular to the longitudinal axis. In addition, the central articulating portion <NUM> may have a concave curvature on the top surface <NUM> of the second member <NUM> and the medial and lateral articulating surfaces <NUM>, <NUM> may have convex curvatures on the top surface <NUM> of the second member <NUM>. The articulating surface <NUM> of the second member <NUM> may include, for example, a coronal radii and the coronal radii may have, for example, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, and a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>. The articulating surface <NUM> of the second member <NUM> may include, for example, a sagittal radii and the sagittal radii may have, for example, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, and a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>.

Referring now to <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, the bottom surface <NUM> of the second member <NUM> may include a first portion <NUM>, a second portion <NUM>, and a third portion <NUM>. The first portion <NUM>, the second portion <NUM>, and the third portion <NUM> may each have, for example, planar surfaces. The second portion <NUM> may be positioned between the first portion <NUM> and the third portion <NUM>. The first portion <NUM> may extend, for example, from the first end <NUM> to a first transition point <NUM>. The second portion <NUM> may extend, for example, from the first transition point <NUM> to a second transition point <NUM>. The third portion <NUM> may extend, for example, from the second transition point <NUM> to the second end <NUM>. The first portion <NUM> may extend away from the second portion <NUM> at a first angle and the third portion <NUM> may extend away from the second portion <NUM> at a second angle. The first angle may be, for example, approximately <NUM>° to <NUM>°, and the second angle may be, for example, approximately <NUM>° to <NUM>°. The bottom surface <NUM> of the second member <NUM> may be, for example, coated or textured with a biocompatible material. The texture or coating may be, for example, a plasma sprayed material, such as, a commercially-pure titanium or other biocompatible material, as known by one of ordinary skill in the art.

The bottom surface <NUM> of the second member <NUM> may also include at least one stem or peg <NUM> extending away from the first portion <NUM> of the bottom surface <NUM>, as shown in <FIG>, <FIG> and <FIG>. The at least one stem <NUM> may be, for example, two stems <NUM>, although other numbers of stems <NUM> are also contemplated. As depicted, the first stem <NUM> is positioned on the first portion <NUM> between the anterior recess <NUM> and the first side <NUM> and the second stem <NUM> is positioned on the first portion <NUM> between the anterior recess <NUM> and the second side <NUM>, as shown in <FIG> and <FIG>. The stems <NUM> may be, for example, positioned slightly medially biased and may be offset, for example, approximately <NUM> from a midpoint of the second member <NUM>. The at least one stem <NUM> may not be, for example, textured or coated, rather the at least one stem <NUM> may be smooth to decrease bone resorption at the resection level. The at least one stem <NUM> may have, for example, a cylindrical, pyramidal, or another quadrilateral prism shape.

Referring to <FIG>, the insert, polyethylene insert or articulating insert <NUM> is shown. The insert <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The insert <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the insert <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The first end <NUM> of the insert <NUM> includes an opening or cylinder <NUM> extending into the insert <NUM> from the first end <NUM> toward the second end <NUM>. The opening <NUM> may be sized and shaped or configured to receive an instrument, for example, a self-tapping screw to engage the insert <NUM> and remove the insert <NUM> from the first member <NUM>.

With continued reference to <FIG> and <FIG>, the top surface <NUM> of the insert <NUM> includes an engagement member or protrusion <NUM>. The engagement member <NUM> includes a first engagement feature or first male dovetail <NUM> on the first side <NUM>, a second engagement feature or second male dovetail <NUM> on the second side <NUM>, and a third engagement feature or third male dovetail <NUM> on the second end <NUM>. When the insert <NUM> is coupled to the first member <NUM>, the first engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the first engagement feature <NUM> of the first member <NUM>, the second engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the second engagement feature <NUM> of the first member <NUM>, and the third engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the third engagement feature <NUM> of the first member <NUM>. The top surface <NUM> also may include a slot or removal engagement feature <NUM> and a locking tab or protrusion <NUM>. The slot <NUM> may be, for example, positioned near and open to the first end <NUM>. The locking tab <NUM> may be, for example, positioned adjacent to the slot <NUM> and extend away from the top surface <NUM> of the insert <NUM>. The locking tab <NUM> may be configured or sized and shaped to engage the locking groove <NUM> of the bottom surface <NUM> of the first member <NUM>.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the insert <NUM> includes a first contact surface or medial contact surface <NUM>, a second contact surface or lateral contact surface <NUM>, and a central contact surface <NUM>. The first contact surface <NUM> extends from the first side <NUM> of the insert <NUM> toward the second side <NUM>. The second contact surface <NUM> extends from the second side <NUM> of the insert <NUM> toward the first side <NUM>. The central contact surface or central sulcus <NUM> is positioned between the first contact surface <NUM> and the second contact surface <NUM>. The first and second contact surfaces <NUM>, <NUM> form a bi-condylar surface, as shown in <FIG>, and <FIG>. The centers of the radii of the bi-condylar surface may be, for example, spaced between approximately <NUM> and <NUM> for all sizes of the insert <NUM>. More specifically, the centers of radii of the bi-condylar surface may be, for example, approximately <NUM> for a size <NUM> insert <NUM>, approximately <NUM> for a size <NUM> insert <NUM>, and approximately <NUM> for a size <NUM> insert <NUM>. The first contact surface <NUM> includes at least one first curvature along a longitudinal axis and at least one second curvature along a lateral axis. The second contact surface <NUM> includes at least one third curvature along a longitudinal axis and at least one fourth curvature along a lateral axis. The central contact surface <NUM> includes at least one curvature. The curvatures of the first and second contact surfaces <NUM>, <NUM> may be, for example, concave curvatures and the at least one curvature of the central contact surface <NUM> may be, for example, a convex curvature. The central contact surface <NUM> may provide, for example, stability in a medial-lateral direction. The central contact surface <NUM> may have, for example, a height ranging from approximately <NUM> and <NUM>. The insert <NUM> may also have a coronal radii and the coronal radii may be, for example, approximately <NUM>. 10x the coronal radii of the talus. In addition, the insert <NUM> may have at least one sagittal radii. The at least one sagittal radii of the insert <NUM> may be, for example, multiple tangent and/or continuous radii, which may include varying levels of conformity with the sagittal radii of the second member <NUM>. The sagittal radii may have, for example, a range of approximately <NUM> to <NUM> for all sizes of the insert <NUM>. More specifically, the sagittal radii may be, for example, approximately <NUM> to <NUM> for the size <NUM> insert <NUM> and approximately <NUM> to <NUM> for the size <NUM> insert <NUM>. In an embodiment the sagittal radii may be, for example, <NUM> for size <NUM> and <NUM> for size <NUM>.

As shown in <FIG>, when assembled and/or implanted, the top surface <NUM> of the insert <NUM> couples to a bottom surface <NUM> of the first member <NUM>. In addition, the top surface <NUM> of the second member <NUM> is configured or sized and shaped to articulate with the bottom surface <NUM> of the insert <NUM>. Specifically, the medial articulating surface <NUM> of the second member <NUM> is configured to articulate with the first contact surface <NUM> of the insert <NUM>, the lateral articulating surface <NUM> of the second member <NUM> is configured to articulate with the second contact surface <NUM> of the insert <NUM>, and the central portion <NUM> of the second member <NUM> is configured to articulate with the third contact surface <NUM> of the insert <NUM>.

A method of inserting an implant <NUM> is shown in <FIG>. The method may include, for example, obtaining an implant <NUM> and making an incision to expose a joint with a first bone and a second bone <NUM>. The implant may be, for example, an implant <NUM> as described in greater detail above with reference to <FIG> and which will not be described again here for brevity sake. The method may also include preparing the bones for receiving the implant <NUM>. Next, the method may include coupling the first member to the first bone <NUM> and coupling the second member to the second bone <NUM>. Then, the method may include inserting a second end of the insert into a first end of the first member <NUM>. In addition, the method may include engaging a locking tab of the insert with a locking groove of the first member <NUM>. In an embodiment, if the insert needs to be removed or replaced, for example, for a different size or due to wear or failure, an instrument may be inserted into the slot of the insert to release the locking tab of the insert from the locking groove of the first member <NUM>. If the insert is removed, a second end of another insert may be inserted into a first end of the first member <NUM> and a locking tab of the new insert may be engaged with the locking groove of the first member <NUM>. Finally, once the desired insert is installed, the method may include closing the incision <NUM>.

Referring now to <FIG>, another implant <NUM> is shown. The implant <NUM> includes a first member or tibia base <NUM>, an insert <NUM>, and a second member, talus component, or articulating member <NUM>. The insert <NUM> includes a top surface <NUM> and a bottom surface <NUM>. The top surface <NUM> of the insert <NUM> couples to the first member <NUM> and the bottom surface <NUM> engages the second member <NUM>.

As shown in <FIG>, the first member <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The first member <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the first member <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The top surface <NUM> may include, for example, an arc shape or curvature extending between the first side <NUM> and the second side <NUM>, as shown in <FIG>, <FIG>. The curvature may have, for example, multiple arc radii, such as, a first arc radius R1, a second arc radius R2, and a third arc radius R3, as shown in <FIG>. The first arc radius R1 may be, for example, positioned near a middle portion of the top surface <NUM> of the first member <NUM>. The second arc radii R2 may be, for example, positioned adjacent to the first arc radius R1 on both sides, such that a second arc radius R2 may be positioned adjacent to the first arc radius R1 on the first side <NUM> and a second arc radius R2 may be positioned adjacent to the first arc radius R1 on the second side <NUM>. Finally, the third arc radii R3 may be, for example, positioned adjacent to one of the second arc radii R2 on each side of the first member <NUM>, such that a third arc radius R3 is positioned between one of the second arc radii R2 and the first side <NUM> and a third arc radius R3 is positioned between the other second arc radius R2 and the second side <NUM>. In one embodiment, the first arc radius R1 may be, for example, approximately <NUM> to <NUM> and more specifically, approximately <NUM>. The second arc radius R2 may be, for example, approximately <NUM> to <NUM> and more specifically approximately <NUM>. The third arc radius R3 may be, for example, approximately <NUM> to <NUM> and more specifically <NUM>. Although not shown, it is also contemplated that the top surface <NUM> of the first member <NUM> may be, for example, flat as the top surface <NUM> extends between the first side <NUM> and the second side <NUM>. The top surface <NUM> of the first member <NUM> may also include, for example, sloped, tapered, or angled sides on the first side <NUM> and the second side <NUM> of the first member <NUM>. The angle of the first and second sides <NUM>, <NUM> as they extend away from the top surface <NUM> may be, for example, approximately <NUM>° to <NUM>° from vertical and more specifically approximately <NUM>° from vertical. The edges of the first and second sides <NUM>, <NUM> of the first member <NUM> may be, for example, rounded or curved.

As shown in the top view of <FIG>, the first and second ends <NUM>, <NUM> may include, for example, multiple arc radii as the first and second ends <NUM>, <NUM> extends between the first side <NUM> and the second side <NUM>. The first end <NUM> may include multiple arc radii, for example, a fourth arc radius R4, a fifth arc radius R5, a sixth arc radius R6, a seventh arc radius R7, an eighth arc radius R8, and a ninth arc radius R9. The apex of the first end <NUM> may be, for example, offset medially from a longitudinal axis of the first member <NUM>. The fourth arc radius R4 may be positioned to the right of the flat or planar surface of the first end <NUM> and the fifth arc radius R5 may be positioned to the left of the flat or planar surface of the first end <NUM>. The fourth and fifth arc radii R4, R5 may be, for example, approximately <NUM> to <NUM>, and more preferably approximately <NUM>. The sixth arc radius R6 may be positioned adjacent to the fourth arc radius R4 toward the first side <NUM> of the first member <NUM>. The seventh arc radius R7 may be positioned adjacent to the fifth arc radius R5 toward the second side <NUM> of the first member <NUM>. The fifth and sixth arc radii R5, R6 may be, for example, approximately <NUM> to <NUM>, and more preferably approximately <NUM>. The eighth arc radius R8 may be positioned adjacent to the sixth arc radius R6 and the eighth arc radius R8 extends to the first side <NUM> of the first member <NUM>. The ninth arc radius R9 may be positioned adjacent to the seventh arc radius R7 and the ninth arc radius R9 extends to the second side <NUM> of the first member <NUM>. The eighth and ninth arc radii R8, R9 may be, for example, approximately <NUM> to <NUM>, and more preferably approximately <NUM>.

The second end <NUM> may also include multiple arc radii, for example, a tenth arc radius R10, an eleventh arc radius R11, and a twelfth arc radius R12. The apex of the second end <NUM> may be, for example, offset laterally from a longitudinal axis of the first member <NUM>. The tenth arc radius R10 may be positioned in the central portion of the second end <NUM> of the first member <NUM>. The tenth arc radius R10 may be, for example, approximately <NUM> to <NUM>, and more preferably approximately <NUM>. The eleventh arc radius R11 may be positioned adjacent to the tenth arc radius R10 and the eleventh arc radius R11 extends to the first side <NUM> of the first member <NUM>. The twelfth arc radius R12may be positioned adjacent to the tenth arc radius R10 and the twelfth arc radius R12 extends to the second side <NUM> of the first member <NUM>. The eleventh and twelfth arc radii R11, R12 may be, for example, approximately <NUM> to <NUM>, and more preferably approximately <NUM>.

The first member <NUM> may have an outer perimeter shape that may be, for example, a quadrilateral shape, such as, a generally trapezoidal from a top or bottom view, as shown in <FIG>, <FIG> and <FIG>. The first and second sides <NUM>, <NUM> may be generally parallel and the first end <NUM> and second end <NUM> may be, for example, angled or curved as they extend from the first side <NUM> to the second side <NUM>. In an embodiment, the length of the first or medial side <NUM> may be, for example, shorter than the length of the second or lateral side <NUM>. The angle or curvature of the first end <NUM> may be, for example, smaller than the angle of the second end <NUM>. The top surface <NUM>, first side <NUM> and second side <NUM> may be, for example, textured or coated to provide a friction-stabilization surface and to allow for bone on-growth. The textured surface may be, for example, plasma sprayed biocompatible material, such as, commercially-pure titanium, or another biocompatible material as known by one of ordinary skill in the art.

With continued reference to <FIG>, the top surface <NUM> of the first member <NUM> includes at least one peg or vertical peg <NUM> extending away from the top surface <NUM>. The at least one peg <NUM> may be, for example, four pegs <NUM>, although alternative numbers of pegs <NUM> are also contemplated. The pegs <NUM> may be, for example, positioned equally spaced around the top surface <NUM> forming, for example, the four points or corners of a quadrilateral, such as a square, rectangle, or diamond shape or alternatively, the four pegs <NUM> may be randomly positioned on the top surface <NUM>. The at least one peg <NUM> may not be, for example, textured, rather the at least one peg <NUM> may be smooth to decrease bone resorption at the resection level.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the first member <NUM> is shown. The bottom surface <NUM> includes a recessed region or engagement region <NUM> extending into the first member <NUM> from the bottom surface <NUM> toward the top surface <NUM>. The first member <NUM> may come in multiple sizes for use with patients having different size tibia bones and the recessed region <NUM> of each of the first members <NUM> will be, for example, sized and shaped the same to allow for replacement of the first member <NUM>, as needed. The bottom surface <NUM> also includes an engagement channel <NUM> extending from the first end <NUM> into the recessed region <NUM>. In addition, the bottom surface <NUM> of the first member <NUM> includes a first engagement feature or first female dovetail portion <NUM> extending from the first side <NUM> into the recessed region <NUM>, a second engagement feature or second female dovetail portion <NUM> extending from the second side <NUM> into the recessed region <NUM>, and a third engagement feature or third female dovetail portion <NUM> extending from a position near the second end <NUM> into the recessed region <NUM>. The bottom surface <NUM> of the first member <NUM> also includes a slot or removal engagement feature <NUM> and a locking groove <NUM> positioned adjacent to the slot <NUM>. The slot <NUM> may be, for example, angled as the slot <NUM> extends from the first end <NUM> toward the locking groove <NUM>.

Referring now to <FIG>, the second member, talus component or articulating member <NUM> has a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The second member <NUM> also has a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the second member <NUM> has a top surface or articulating surface <NUM> opposite a bottom surface or bone engagement surface <NUM>. The second member <NUM> may have, for example, a trapezium shape, as shown in <FIG> and <FIG>. The first side <NUM> and second side <NUM> may be angled as they extend from the top surface <NUM> to the bottom surface <NUM> and the angle may be, for example, approximately <NUM>° to <NUM>° and more preferably approximately <NUM>°. The first side <NUM> may be, for example, shorter than the second side <NUM>. As shown in <FIG>, and <FIG>, at least a portion of the first and second sides <NUM>, <NUM> may be, for example, angled or tapered from the top surface <NUM> toward the bottom surface <NUM>. The second member <NUM> includes an anterior recess <NUM> extending into the first end <NUM>. The anterior recess <NUM> may be, for example, positioned near a midpoint of a lateral axis of the second member <NUM> or, alternatively may be medially biased. The second member <NUM> also includes a posterior recess <NUM> extending into the second end <NUM>. The posterior recess <NUM> may be, for example, positioned near a midpoint of the lateral axis of the second member <NUM> or, alternatively may be medially biased.

As shown in <FIG> and <FIG>, the top surface <NUM> of the second member <NUM> includes a medial articulating surface <NUM> extending from the first side <NUM> of the second member <NUM> toward the second side <NUM>. The top surface <NUM> may also include a lateral articulating surface <NUM> extending from the second side <NUM> of the second member <NUM> toward the first side <NUM>. In addition, the top surface <NUM> also includes a central articulating portion <NUM> positioned at a point where the medial articulating surface <NUM> contacts the lateral articulating surface <NUM>.

The medial articulating surface <NUM> may include at least one first curvature along a longitudinal axis and at least one second curvature perpendicular to the longitudinal axis, as shown in <FIG>. The lateral articulating surface <NUM> has at least one third curvature along the longitudinal axis and at least one fourth curvature perpendicular to the longitudinal axis. In addition, the central articulating portion <NUM> may have a concave curvature on the top surface <NUM> of the second member <NUM> and the medial and lateral articulating surfaces <NUM>, <NUM> may have convex curvatures on the top surface <NUM> of the second member <NUM>. The articulating surface <NUM> of the second member <NUM> may include, for example, at least one coronal radii and the at least one coronal radii may have, for example, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, and a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>. The articulating surface <NUM> of the second member <NUM> may include, for example, at least one sagittal radii and the at least one sagittal radii may have, for example, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>, and a range of approximately <NUM> to <NUM> for a size <NUM> second member <NUM>. In an embodiment, the anterior portion of the second member <NUM> may include a first sagittal radius of the lateral articulating surface <NUM> and a second sagittal radius of the medial articulating surface <NUM>. The first sagittal radius may be, for example, larger than the second sagittal radius. In addition, the posterior portion of the second member <NUM> may include a third sagittal radius of the lateral articulating surface <NUM> and a fourth sagittal radius of the medial articulating surface <NUM>. The third sagittal radius may be, for example, smaller than the fourth sagittal radius. A larger anterior lateral sagittal radius than anterior medial sagittal radius and a smaller posterior lateral sagittal radius than posterior medial sagittal radius allow for the joint axis of rotation to point distally and laterally during dorsiflexion and distally and medially during plantarflexion.

The bottom surface <NUM> of the second member <NUM> may also include at least one stem or peg <NUM> extending away from the first portion <NUM> of the bottom surface <NUM>, as shown in <FIG>, <FIG> and <FIG>. The at least one stem <NUM> may be, for example, two stems <NUM>, although other numbers of stems <NUM> are also contemplated. As depicted, the first stem <NUM> is positioned on the first portion <NUM> between the anterior recess <NUM> and the first side <NUM> and the second stem <NUM> is positioned on the first portion <NUM> between the anterior recess <NUM> and the second side <NUM>, as shown in <FIG> and <FIG>. The stems <NUM> may be, for example, positioned slightly medially biased and may be offset, for example, approximately <NUM> from a midpoint of the second member <NUM>. The at least one stem <NUM> may not be, for example, textured or coated, rather the at least one stem <NUM> may be smooth to decrease bone resorption at the resection level. The at least one stem <NUM> may have, for example, a cylindrical, pyramidal, or other quadrilateral prism shape.

Referring to <FIG>, the insert, bearing insert, polyethylene insert or articulating insert <NUM> is shown. The insert <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The insert <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the insert <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The first end <NUM> of the insert <NUM> includes an opening or cylinder <NUM> extending into the insert <NUM> from the first end <NUM> toward the second end <NUM>. The opening <NUM> may be sized and shaped or configured to receive an instrument or member, for example, a self-tapping screw to engage the insert <NUM> and remove the insert <NUM> from the first member <NUM>. The first and second sides <NUM>, <NUM> may be, for example, angled or tapered along at least a portion of the sides <NUM>, <NUM> as the sides <NUM>, <NUM> extend from the top surface <NUM> toward the bottom surface <NUM>, as shown in <FIG>, <FIG>.

With continued reference to <FIG> and <FIG>, the top surface <NUM> of the insert <NUM> includes an engagement member or protrusion <NUM>. The engagement member <NUM> includes a first engagement feature or first male dovetail <NUM> near the first side <NUM>, a second engagement feature or second male dovetail <NUM> near the second side <NUM>, and a third engagement feature or third male dovetail <NUM> near the second end <NUM>. When the insert <NUM> is coupled to the first member <NUM>, the first engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the first engagement feature <NUM> of the first member <NUM>, the second engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the second engagement feature <NUM> of the first member <NUM>, and the third engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the third engagement feature <NUM> of the first member <NUM>. The top surface <NUM> also includes a locking tab or protrusion <NUM>. The locking tab <NUM> may, for example, extend away from the top surface <NUM> of the insert <NUM>. The locking tab <NUM> may form, for example, a ramped portion extending from the top surface <NUM> of the insert <NUM> on the side positioned toward the second end <NUM> to a side positioned toward the first end <NUM>. The side of the locking tab <NUM> positioned toward the first end <NUM> may have a height taller than the height of the side of the locking tab <NUM> positioned toward the second end <NUM>. The locking tab <NUM> may be configured or sized and shaped to engage the locking groove <NUM> of the bottom surface <NUM> of the first member <NUM>.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the insert <NUM> includes a first contact surface or medial contact surface <NUM>, a second contact surface or lateral contact surface <NUM>, and a central contact surface <NUM>. The first contact surface <NUM> extends along at least a portion of the bottom surface <NUM> in a medial-lateral direction from the first side <NUM> toward the second side <NUM>. The first contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The second contact surface <NUM> extends along at least a portion of the bottom surface <NUM> from the second side <NUM> toward the first side <NUM>. The second contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The central contact surface or central sulcus <NUM> is positioned between the first contact surface <NUM> and the second contact surface <NUM>. The central contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The first and second contact surfaces <NUM>, <NUM> form a bi-condylar surface, as shown in <FIG>, and <FIG>. The centers of the radii of the bi-condylar surface may be, for example, spaced between approximately <NUM> and <NUM> for all sizes of the insert <NUM>. More specifically, the centers of radii of the bi-condylar surface may be, for example, approximately <NUM> for a size <NUM> insert <NUM>, approximately <NUM> for a size <NUM> insert <NUM>, and approximately <NUM> for a size <NUM> insert <NUM>.

With continued reference to <FIG> and <FIG>, the first contact surface <NUM> includes at least one first curvature along a longitudinal axis and at least one second curvature along a lateral axis. The second contact surface <NUM> includes at least one third curvature along a longitudinal axis and at least one fourth curvature along a lateral axis. The central contact surface <NUM> includes at least one curvature. The curvatures of the first and second contact surfaces <NUM>, <NUM> may be, for example, concave curvatures and the at least one curvature of the central contact surface <NUM> may be, for example, a convex curvature. The central contact surface <NUM> may provide, for example, stability in a medial-lateral direction. The central contact surface <NUM> may have, for example, a height ranging from approximately <NUM> and <NUM>. The insert <NUM> may also have a coronal radii and the coronal radii may be, for example, approximately <NUM> times the coronal radii of the talus. In addition, the insert <NUM> may have at least one sagittal radii. The at least one sagittal radii of the insert <NUM> may be, for example, multiple tangent and/or continuous radii, which may include varying levels of conformity with the sagittal radii of the second member <NUM>. The sagittal radii may have, for example, a range of approximately <NUM> to <NUM> for all sizes of the insert <NUM>. More specifically, the sagittal radii may be, for example, approximately <NUM> to <NUM> for the size <NUM> insert <NUM> and approximately <NUM> to <NUM> for the size <NUM> insert <NUM>.

Referring now to <FIG>, <FIG>, <FIG> and <FIG>, the bottom surface <NUM> may also include, for example, a first angled or tapered portion <NUM> and a second angled or tapered portion <NUM>. The first angled portion <NUM> may be, for example, positioned to extend from the first end <NUM> to the anterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, positioned to extend from the second end <NUM> to the posterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>.

As shown in <FIG>, the first member <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The first member <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the first member <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The top surface <NUM> may include, for example, an arc shape or curvature extending between the first side <NUM> and the second side <NUM>, as shown in <FIG>, <FIG>. The curvature may have, for example, multiple arc radii, which in an embodiment may be the same or similar to the arc radii described with reference to <FIG> in greater detail above and in other embodiments the multiple arc radii may be different than described above with reference to <FIG>. The top surface <NUM> of the first member <NUM> may also include, for example, sloped, tapered, or angled sides on the first side <NUM> and the second side <NUM> of the first member <NUM>. The angle of the first and second sides <NUM>, <NUM> as they extend away from the top surface <NUM> may be, for example, approximately <NUM>° to <NUM>° from vertical and more specifically approximately <NUM>° from vertical. The edges of the first and second sides <NUM>, <NUM> of the first member <NUM> may be, for example, rounded or curved.

As shown in the top view of <FIG>, the first and second ends <NUM>, <NUM> may include, for example, multiple arc radii as the first and second ends <NUM>, <NUM> extend between the first side <NUM> and the second side <NUM>. In an embodiment, the multiple arc radii of the first member <NUM> may be as described in greater detail above with reference to <FIG>, which will not be described again here for brevity sake. In other embodiments the multiple arc radii may be different as described with respect to <FIG>.

With continued reference to <FIG>, the top surface <NUM> of the first member <NUM> includes at least one peg or vertical peg <NUM> extending away from the top surface <NUM>. The at least one peg <NUM> may be, for example, two pegs <NUM>, although alternative numbers of pegs <NUM> are also contemplated. The pegs <NUM> may be, for example, positioned equally spaced apart on the top surface <NUM> or alternatively, the two pegs <NUM> may be randomly positioned on the top surface <NUM>. The at least one peg <NUM> may not be, for example, textured, rather the at least one peg <NUM> may be smooth to decrease bone resorption at the resection level.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the first member <NUM> is shown. The bottom surface <NUM> includes a recessed region or engagement region <NUM> extending into the first member <NUM> from the bottom surface <NUM> toward the top surface <NUM>. The first member <NUM> may come in multiple sizes for use with patients having different size tibia bones and the recessed region <NUM> of each of the first members <NUM> will be, for example, sized and shaped the same to allow for replacement of the first member <NUM>, as needed. The bottom surface <NUM> also includes an engagement channel <NUM> extending from the first end <NUM> into the recessed region <NUM>. In addition, the bottom surface <NUM> of the first member <NUM> includes a first engagement feature or first female dovetail portion <NUM> extending from the first side <NUM> into the recessed region <NUM>, a second engagement feature or second female dovetail portion <NUM> extending from the second side <NUM> into the recessed region <NUM>, and a third engagement feature or third female dovetail portion <NUM> extending from a position near the second end <NUM> into the recessed region <NUM>. The bottom surface <NUM> of the first member <NUM> also includes a slot or removal engagement feature <NUM> and a locking groove <NUM> positioned adjacent to the slot <NUM>. The slot <NUM> may be, for example, angled as the slot <NUM> extends from the first end <NUM> toward the locking groove <NUM>. As shown in <FIG>, the engagement channel <NUM> may have a first width at the opening at the first end <NUM> and a second width at the closed end near the second end <NUM>. The first width may be, for example, wider than the second width. At least a portion of the first engagement feature <NUM> and at least a portion of the second engagement feature <NUM> may be, for example, tapered or curved between the first width at the opening of the first end <NUM> and the second width. The second width may extend from a position adjacent to the locking groove <NUM> to the closed end of the engagement channel <NUM>.

Referring now to <FIG>, the second member, talus component or articulating member <NUM> has a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The second member <NUM> also has a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the second member <NUM> has a top surface or articulating surface <NUM> opposite a bottom surface or bone engagement surface <NUM>. The second member <NUM> may have, for example, a trapezium shape, as shown in <FIG>. The first side <NUM> and second side <NUM> may be angled as they extend from the top surface <NUM> to the bottom surface <NUM> and the angle may be, for example, approximately <NUM>° to <NUM>° and more preferably approximately <NUM>°. The first side <NUM> may be, for example, shorter than the second side <NUM>. As shown in <FIG>, and <FIG>, at least a portion of the first and second sides <NUM>, <NUM> may be, for example, angled or tapered from the top surface <NUM> toward the bottom surface <NUM>. The second member <NUM> includes an anterior recess <NUM> extending into the first end <NUM>. The anterior recess <NUM> may be, for example, positioned near a midpoint of a lateral axis of the second member <NUM> or, alternatively may be medially biased. The second member <NUM> also includes a posterior recess <NUM> extending into the second end <NUM>. The posterior recess <NUM> may be, for example, positioned near a midpoint of the lateral axis of the second member <NUM> or, alternatively may be medially biased.

The bottom surface <NUM> of the second member <NUM> may also include at least one fin or stem <NUM> extending away from the first portion <NUM> of the bottom surface <NUM>, as shown in <FIG>, <FIG> and <FIG>. The at least one fin <NUM> may be, for example, one fin <NUM>, although other numbers of fins <NUM> are also contemplated. As depicted, the first fin <NUM> is positioned on the first portion <NUM> aligned with the anterior recess <NUM>, as shown in <FIG> and <FIG>. The fin <NUM> may be, for example, tapered at the distal end. The at least one fin <NUM> may not be, for example, textured or coated, rather the at least one fin <NUM> may be smooth to decrease bone resorption at the resection level. The at least one fin <NUM> may have, for example, a cylindrical, round, oval or other like shape.

Referring to <FIG>, the insert, bearing insert, polyethylene insert or articulating insert <NUM> is shown. The insert <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The insert <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the insert <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The first end <NUM> of the insert <NUM> includes at least one opening or cylinder <NUM> extending into the insert <NUM> from the first end <NUM> toward the second end <NUM>. The at least one opening <NUM> may be sized and shaped or configured to receive an instrument or member, for example, a fastener or instrument to engage the insert <NUM> and remove the insert <NUM> from the first member <NUM>. The first and second sides <NUM>, <NUM> may be, for example, angled or tapered along at least a portion of the sides <NUM>, <NUM> as the sides <NUM>, <NUM> extend from the top surface <NUM> toward the bottom surface <NUM>, as shown in <FIG>, <FIG>.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the insert <NUM> includes a first contact surface or medial contact surface <NUM>, a second contact surface or lateral contact surface <NUM>, and a central contact surface <NUM>. The first contact surface <NUM> extends along at least a portion of the bottom surface <NUM> in a medial-lateral direction from the first side <NUM> toward the second side <NUM>. The first contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The second contact surface <NUM> extends along at least a portion of the bottom surface <NUM> from the second side <NUM> toward the first side <NUM>. The second contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The central contact surface or central sulcus <NUM> is positioned between the first contact surface <NUM> and the second contact surface <NUM>. The central contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The first and second contact surfaces <NUM>, <NUM> form a bi-condylar surface, as shown in <FIG>, and <FIG> The centers of the radii of the bi-condylar surface may be, for example, spaced between approximately <NUM> and <NUM> for all sizes of the insert <NUM>. More specifically, the centers of radii of the bi-condylar surface may be, for example, approximately <NUM> for a size <NUM> insert <NUM>, approximately <NUM> for a size <NUM> insert <NUM>, and approximately <NUM> for a size <NUM> insert <NUM>.

Referring now to <FIG>, <FIG>, <FIG> and <FIG>, the bottom surface <NUM> may also include, for example, a first angled or tapered portion <NUM> and a second angled or tapered portion <NUM>. The first angled portion <NUM> may be, for example, positioned to extend from the first end <NUM> to the anterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, positioned to extend from the second end <NUM> to the posterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The first angled portion <NUM> and the second angled portion <NUM> may alternatively be, for example, non-planar surfaces including at least one concave or convex curvature. The non-planar surfaces may, for example, still be angled or tapered between the ends <NUM>, <NUM> and the contact surfaces <NUM>, <NUM>, <NUM> of the insert <NUM>.

Referring now to <FIG>, an implant <NUM> is shown. The implant <NUM> includes a first member or tibia base <NUM>, an insert <NUM>, and a second member, talus component, or articulating member <NUM>. The first member <NUM> and the second member <NUM> may be of the type described above with reference to implant <NUM> and <FIG>. The insert <NUM> includes a top surface <NUM> and a bottom surface <NUM>. The top surface <NUM> of the insert <NUM> couples to the first member <NUM> and the bottom surface <NUM> engages the second member <NUM>.

With continued reference to <FIG>, the insert, bearing insert, polyethylene insert or articulating insert <NUM> is shown. The insert <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The insert <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the insert <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The first end <NUM> of the insert <NUM> includes at least one opening or cylinder <NUM> extending into the insert <NUM> from the first end <NUM> toward the second end <NUM>. The at least one opening <NUM> may be sized and shaped or configured to receive an instrument or member, for example, a fastener or instrument to engage the insert <NUM> and remove the insert <NUM> from the first member <NUM>. The first and second sides <NUM>, <NUM> may be, for example, angled or tapered along at least a portion of the sides <NUM>, <NUM> as the sides <NUM>, <NUM> extend from the top surface <NUM> toward the bottom surface <NUM>, as shown in <FIG>, <FIG>.

With continued reference to <FIG> and <FIG>, the top surface <NUM> of the insert <NUM> is the same or similar to the top surface <NUM> of the insert <NUM>. The top surface <NUM> includes an engagement member or protrusion <NUM>, which is the same or similar to the engagement member or protrusion <NUM>. The engagement member <NUM> includes a first engagement feature or first male dovetail <NUM> near the first side <NUM>, which is the same or similar to the first engagement feature or first male dovetail <NUM> and which will not be described again here in detail for brevity sake. The engagement member <NUM> also includes a second engagement feature or second male dovetail <NUM> near the second side <NUM>, which is the same or similar to the second engagement feature or second male dovetail <NUM> and which will not be described again here in detail for brevity sake. The engagement member <NUM> may further include a third engagement feature or third male dovetail <NUM> near the second end <NUM>, which is the same or similar to the third engagement feature or third male dovetail <NUM> and which will not be described again here in detail for brevity sake. When the insert <NUM> is coupled to the first member <NUM>, the first engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the first engagement feature <NUM> of the first member <NUM>, the second engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the second engagement feature <NUM> of the first member <NUM>, and the third engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the third engagement feature <NUM> of the first member <NUM>. The top surface <NUM> also includes a locking tab or protrusion <NUM>. The locking tab <NUM> may be the same or similar to the locking tab <NUM> of insert <NUM> as described in greater detail above and which will not be described again here for brevity sake. The locking tab <NUM> may be configured or sized and shaped to engage the locking groove <NUM> of the bottom surface <NUM> of the first member <NUM>.

Referring now to <FIG>, <FIG>, <FIG> and <FIG>, the bottom surface <NUM> of the insert <NUM> includes a first contact surface or medial contact surface <NUM>, a second contact surface or lateral contact surface <NUM>, and a central contact surface <NUM>. The first contact surface <NUM> extends along at least a portion of the bottom surface <NUM> in a medial-lateral direction from the first side <NUM> toward the second side <NUM>. The first contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The second contact surface <NUM> extends along at least a portion of the bottom surface <NUM> from the second side <NUM> toward the first side <NUM>. The second contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The central contact surface or central sulcus <NUM> is positioned between the first contact surface <NUM> and the second contact surface <NUM>. The central contact surface <NUM> also extends along at least a portion of the bottom surface <NUM> in an anterior-posterior direction from a position near the first end <NUM> toward a position near the second end <NUM>. The first and second contact surfaces <NUM>, <NUM> form a bi-condylar surface, as shown in <FIG>, and <FIG>. The centers of the radii of the bi-condylar surface may be, for example, spaced between approximately <NUM> and <NUM> for all sizes of the insert <NUM>. More specifically, the centers of radii of the bi-condylar surface may be, for example, approximately <NUM> for a size <NUM> insert <NUM>, approximately <NUM> for a size <NUM> insert <NUM>, and approximately <NUM> for a size <NUM> insert <NUM>.

Referring now to <FIG>, <FIG>, <FIG> and <FIG>, the bottom surface <NUM> may also include, for example, a first angled or tapered portion <NUM> and a second angled or tapered portion <NUM>. The first angled portion <NUM> may be, for example, positioned to extend from the first end <NUM> to the anterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The first angled portion <NUM> may be, for example, longer than the first angled portion <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, positioned to extend from the second end <NUM> to the posterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, shorter than the second angled portion <NUM> of the insert <NUM>. The first angled portion <NUM> and the second angled portion <NUM> may alternatively be, for example, non-planar surfaces including at least one concave or convex curvature. The non-planar surfaces may, for example, still be angled or tapered between the ends <NUM>, <NUM> and the contact surfaces <NUM>, <NUM>, <NUM> of the insert <NUM>.

As shown in <FIG>, when assembled and/or implanted, the top surface <NUM> of the insert <NUM> couples to a bottom surface <NUM> of the first member <NUM>. In addition, the top surface <NUM> of the second member <NUM> is configured or sized and shaped to articulate with the bottom surface <NUM> of the insert <NUM>. Specifically, the medial articulating surface <NUM> of the second member <NUM> is configured to articulate with the first contact surface <NUM> of the insert <NUM>, the lateral articulating surface <NUM> of the second member <NUM> is configured to articulate with the second contact surface <NUM> of the insert <NUM>, and the central portion <NUM> of the second member <NUM> is configured to articulate with the third contact surface <NUM> of the insert <NUM>. As shown in <FIG>, the first member <NUM> and coupled insert <NUM> are positioned on the second member <NUM> such that the first member <NUM> and insert <NUM> are shifted in an anterior direction on the second member <NUM>. The implant <NUM> includes an insert <NUM> to anteriorly shift the first member <NUM> relative to the second member <NUM> and the neutral positioning of implant <NUM>.

With continued reference to <FIG> and <FIG> the top surface <NUM> of the insert <NUM> is the same or similar to the top surface <NUM> of the insert <NUM> and the top surface <NUM> of the insert <NUM>. The top surface <NUM> includes an engagement member or protrusion <NUM>, which is the same or similar to the engagement member or protrusion <NUM>, <NUM>. The engagement member <NUM> includes a first engagement feature or first male dovetail <NUM> near the first side <NUM>, which is the same or similar to the first engagement feature or first male dovetail <NUM>, <NUM> and which will not be described again here in detail for brevity sake. The engagement member <NUM> also includes a second engagement feature or second male dovetail <NUM> near the second side <NUM>, which is the same or similar to the second engagement feature or second male dovetail <NUM>, <NUM> and which will not be described again here in detail for brevity sake. The engagement member <NUM> may further include a third engagement feature or third male dovetail <NUM> near the second end <NUM>, which is the same or similar to the third engagement feature or third male dovetail <NUM>, <NUM> and which will not be described again here in detail for brevity sake. When the insert <NUM> is coupled to the first member <NUM>, the first engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the first engagement feature <NUM> of the first member <NUM>, the second engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the second engagement feature <NUM> of the first member <NUM>, and the third engagement feature <NUM> of the insert <NUM> may be configured or sized and shaped to engage the third engagement feature <NUM> of the first member <NUM>. The top surface <NUM> also includes a locking tab or protrusion <NUM>. The locking tab <NUM> may be the same or similar to the locking tab <NUM>, <NUM> of insert <NUM>, <NUM>, respectively, as described in greater detail above and which will not be described again here for brevity sake. The locking tab <NUM> may be configured or sized and shaped to engage the locking groove <NUM> of the bottom surface <NUM> of the first member <NUM>.

Referring now to <FIG>, <FIG> and <FIG>, the bottom surface <NUM> may also include, for example, a first angled or tapered portion <NUM> and a second angled or tapered portion <NUM>. The first angled portion <NUM> may be, for example, positioned to extend from the first end <NUM> to the anterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The first angled portion <NUM> may be, for example, shorter than the first angled portion <NUM> of the insert <NUM> and the first angled portion <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, positioned to extend from the second end <NUM> to the posterior portion of the contact surfaces <NUM>, <NUM>, <NUM> of the bottom surface <NUM> of the insert <NUM>. The second angled portion <NUM> may be, for example, longer than the second angled portion <NUM> of the insert <NUM> and the second angled portion <NUM> of the insert <NUM>. The first angled portion <NUM> and the second angled portion <NUM> may alternatively be, for example, non-planar surfaces including at least one concave or convex curvature. The non-planar surfaces may, for example, still be angled or tapered between the ends <NUM>, <NUM> and the contact surfaces <NUM>, <NUM>, <NUM> of the insert <NUM>.

As shown in <FIG>, when assembled and/or implanted, the top surface <NUM> of the insert <NUM> couples to a bottom surface <NUM> of the first member <NUM>. In addition, the top surface <NUM> of the second member <NUM> is configured or sized and shaped to articulate with the bottom surface <NUM> of the insert <NUM>. Specifically, the medial articulating surface <NUM> of the second member <NUM> is configured to articulate with the first contact surface <NUM> of the insert <NUM>, the lateral articulating surface <NUM> of the second member <NUM> is configured to articulate with the second contact surface <NUM> of the insert <NUM>, and the central portion <NUM> of the second member <NUM> is configured to articulate with the third contact surface <NUM> of the insert <NUM>. As shown in <FIG>, the first member <NUM> and coupled insert <NUM> are positioned on the second member <NUM> such that the first member <NUM> and insert <NUM> are shifted in a posterior direction on the second member <NUM>. The implant <NUM> includes an insert <NUM> to posteriorly shift the first member <NUM> relative to the second member <NUM> and the neutral positioning of implant <NUM>.

Referring now to <FIG>, another implant <NUM> is shown. The implant <NUM> includes a first member or tibia base <NUM>, an insert <NUM>, and a second member, talus component, or articulating member <NUM>. The insert <NUM> and second member <NUM> are as described in greater detail above and will not be described again here for brevity sake. The top surface <NUM> of the insert couples to the first member <NUM> and the bottom surface <NUM> engages the second member <NUM>.

As shown in <FIG>, the first member <NUM> includes a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The first member <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the first member <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The top surface <NUM> may be, for example, flat as the top surface <NUM> extends between the first side <NUM> and the second side <NUM>, as shown in <FIG>, <FIG>. The top surface <NUM> of the first member <NUM> may also include, for example, sloped, tapered, or angled sides on the first side <NUM> and the second side <NUM> of the first member <NUM>. The angle of the first and second sides <NUM>, <NUM> as they extend away from the top surface <NUM> may be, for example, approximately <NUM>° to <NUM>° from vertical and more specifically approximately <NUM>° from vertical. The edges of the first and second sides <NUM>, <NUM> of the first member <NUM> may be, for example, rounded or curved.

As shown in the top view of <FIG>, the first and second ends <NUM>, <NUM> may include, for example, multiple arc radii as the first and second ends <NUM>, <NUM> extend between the first side <NUM> and the second side <NUM>. In an embodiment, the multiple arc radii of the first member <NUM> may be the same or similar to the multiple arc radii as described in greater detail above with reference to <FIG>, which will not be described again here for brevity sake. In other embodiments the multiple arc radii may be different as described with respect to <FIG>.

The first member <NUM> may have an outer perimeter shape that may be, for example, a quadrilateral shape, such as, a generally trapezoidal from a top or bottom view, as shown in <FIG>, <FIG>. The first and second sides <NUM>, <NUM> may be generally parallel and the first end <NUM> and second end <NUM> may be, for example, angled or curved as they extend from the first side <NUM> to the second side <NUM>. In an embodiment, the length of the first or medial side <NUM> may be, for example, shorter than the length of the second or lateral side <NUM>. The angle or curvature of the first end <NUM> may be, for example, smaller than the angle of the second end <NUM>. The top surface <NUM>, first side <NUM> and second side <NUM> may be, for example, textured or coated to provide a friction-stabilization surface and to allow for bone on-growth. The textured surface may be, for example, plasma sprayed biocompatible material, such as, commercially-pure titanium, or another biocompatible material as known by one of ordinary skill in the art.

With continued reference to <FIG>, the top surface <NUM> of the first member <NUM> includes at least one peg or vertical peg <NUM> extending away from the top surface <NUM>. The at least one peg <NUM> may be as described in greater detail above with reference to implant <NUM> and will not be described again here for brevity sake.

Referring now to <FIG> and <FIG>, the bottom surface <NUM> of the first member <NUM> is shown. The bottom surface <NUM> of the first member <NUM> may be the same or similar to the bottom surface <NUM> of first member <NUM>. Specifically, the bottom surface <NUM> may include a recessed region or engagement region <NUM>, an engagement channel <NUM>, a first engagement feature or first female dovetail portion <NUM>, a second engagement feature or second female dovetail portion <NUM>, a third engagement feature or third female dovetail portion <NUM>, a slot or removal engagement feature <NUM>, a locking groove <NUM>, each of which is described in greater detail above with reference to implant <NUM> and which will not be described again here for brevity sake.

As shown in <FIG>, when assembled and/or implanted, the top surface <NUM> of the insert <NUM> couples to a bottom surface <NUM> of the first member <NUM>. In addition, the top surface <NUM> of the second member <NUM> is configured or sized and shaped to articulate with the bottom surface <NUM> of the insert <NUM>. Specifically, the medial articulating surface <NUM> of the second member <NUM> is configured to articulate with the first contact surface <NUM> of the insert <NUM>, the lateral articulating surface <NUM> of the second member <NUM> is configured to articulate with the second contact surface <NUM> of the insert <NUM>, and the central portion <NUM> of the second member <NUM> is configured to articulate with the third contact surface <NUM> of the insert <NUM>. As shown in <FIG>, the first member <NUM> and coupled insert <NUM> are positioned on the second member <NUM> such that the first member <NUM> and insert <NUM> are in a neutral position.

Referring now to <FIG>, shows an implant kit <NUM>. The implant kit <NUM> may include at least one first member <NUM>, at least one first member <NUM>, at least one insert <NUM>, at least one second member <NUM>, and at least one second member <NUM>. Additional inserts <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may also be included in the implant kit <NUM>. Further, additional first members and second members described herein may be included in the kit <NUM> in place of or in addition to first members <NUM>, <NUM> and second members <NUM>, <NUM>.

With continued reference to <FIG>, the insert, bearing insert, polyethylene insert or articulating insert <NUM> may include a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The insert <NUM> also includes a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the insert <NUM> includes a top surface <NUM> opposite a bottom surface <NUM>. The first and second sides <NUM>, <NUM> may be, for example, angled or tapered along at least a portion of the sides <NUM>, <NUM> as the sides <NUM>, <NUM> extend from the top surface <NUM> toward the bottom surface <NUM>, as shown in <FIG>. The insert <NUM> may be, for example, a <NUM> insert.

The insert <NUM> may also include at least one opening <NUM> as described in greater detail above with respect to insert <NUM> which will not be described again here for brevity sake. The insert <NUM> may also include an engagement member or protrusion <NUM> with a first engagement feature or first male dovetail <NUM> near the first side <NUM>, a second engagement feature or second male dovetail <NUM> near the second side <NUM>, and a third engagement feature or third male dovetail <NUM> near the second end <NUM>. The protrusion <NUM>, first engagement feature <NUM>, second engagement feature <NUM>, and third engagement feature <NUM> are described in greater detail above with reference to insert <NUM> and will not be described again here for brevity sake. The top surface <NUM> may also include a locking tab or protrusion <NUM>, which is also described in greater detail above with reference to insert <NUM> and which will not be described again here for brevity sake.

The bottom surface <NUM> of insert <NUM>, as shown in <FIG>, may include the first contact surface or medial contact surface <NUM>, the second contact surface or lateral contact surface <NUM>, and the central contact surface <NUM>, as described in greater detail above with reference to insert <NUM> and which will not be described again here for brevity sake. The bottom surface <NUM> may further include the first angled or tapered portion <NUM> and the second angled or tapered portion <NUM>, as described in greater detail above with reference to insert <NUM> and which will not be described again here for brevity sake.

When assembled and/or implanted, the top surface <NUM> of the insert <NUM> couples to a bottom surface <NUM>, <NUM> of a first member <NUM>, <NUM>. In addition, the top surface <NUM> of the second member <NUM>, <NUM> is configured or sized and shaped to articulate with the bottom surface <NUM> of the insert <NUM>. Specifically, the medial articulating surface <NUM>, # of the second member <NUM>, <NUM> is configured to articulate with the first contact surface <NUM> of the insert <NUM>, the lateral articulating surface <NUM>, # of the second member <NUM>, <NUM> is configured to articulate with the second contact surface <NUM> of the insert <NUM>, and the central portion <NUM>, # of the second member <NUM>, <NUM> is configured to articulate with the third contact surface <NUM> of the insert <NUM>.

Referring now to <FIG>, another implant <NUM> is shown. The implant <NUM> includes a first member or tibia base <NUM>, an insert <NUM>, and a second member, talus component, or articulating member <NUM>. The first member <NUM> and insert <NUM> are as described in greater detail above and will not be described again here for brevity sake. The top surface <NUM> of the insert couples to the first member <NUM> and the bottom surface <NUM> engages the second member <NUM>.

As shown in <FIG>, the second member, talus component or articulating member <NUM> has a first end or anterior end <NUM> opposite a second end or posterior end <NUM>. The second member <NUM> also has a first side or medial side <NUM> opposite a second side or lateral side <NUM>. In addition, the second member <NUM> has a top surface or articulating surface <NUM> opposite a bottom surface or bone engagement surface <NUM>. The second member <NUM> may have, for example, a trapezium shape, as shown in <FIG>, <FIG>. The first side <NUM> and second side <NUM> may be angled as they extend from the top surface <NUM> to the bottom surface <NUM> and the angle may be, for example, approximately <NUM>° to <NUM>° and more preferably approximately <NUM>°. The first side <NUM> may be, for example, shorter than the second side <NUM>. As shown in <FIG>, and <FIG>, at least a portion of the first and second sides <NUM>, <NUM> may be, for example, angled or tapered from the top surface <NUM> toward the bottom surface <NUM>. The second member <NUM> includes an anterior recess <NUM> extending into the first end <NUM>. The anterior recess <NUM> may be, for example, positioned near a midpoint of a lateral axis of the second member <NUM> or, alternatively may be medially biased. The second member <NUM> also includes a posterior recess <NUM> extending into the second end <NUM>. The posterior recess <NUM> may be, for example, positioned near a midpoint of the lateral axis of the second member <NUM> or, alternatively may be medially biased.

Referring now to <FIG>, <FIG>, the bottom surface <NUM> of the second member <NUM> may be a flat or planar surface. The bottom surface <NUM> of the second member <NUM> may be, for example, coated or textured with a biocompatible material. The texture or coating may be, for example, a plasma sprayed material, such as, a commercially-pure titanium or other biocompatible material, as known by one of ordinary skill in the art. The bottom surface <NUM> of the second member <NUM> may also include at least one stem or peg <NUM> extending away from the bottom surface <NUM>, as shown in <FIG>, <FIG> and <FIG>. The at least one stem <NUM> may be, for example, two stems <NUM>, although other numbers of stems <NUM> are also contemplated. As depicted, the first stem <NUM> is positioned between the anterior recess <NUM> and the first side <NUM> and the second stem <NUM> is positioned between the anterior recess <NUM> and the second side <NUM>, as shown in <FIG> and <FIG>. The stems <NUM> may be, for example, positioned slightly medially biased and may be offset, for example, approximately <NUM> from a midpoint of the second member <NUM>. The at least one stem <NUM> may not be, for example, textured or coated, rather the at least one stem <NUM> may be smooth to decrease bone resorption at the resection level. The at least one stem <NUM> may have, for example, a cylindrical, pyramidal, or other quadrilateral prism shape.

Referring now to <FIG>, the articulation paths of the second member, talus component, or articulating member <NUM> are shown. Although not show, the same or similar articulation paths may also be found on the second member <NUM>. Referring now to <FIG>, a midpoint <NUM> extending between the first side <NUM> and the second side <NUM> separates the anterior articulation <NUM> and the posterior articulation <NUM>. As shown in <FIG>, the anterior articulation <NUM> curves in a medial direction and the posterior articulation <NUM> curves in a lateral direction. Referring now to <FIG>, the anterior articulation <NUM> may have a first diameter and the posterior articulation <NUM> may have a second diameter. The first diameter may be smaller than the second diameter.

Referring now to <FIG>, the anterior articulation <NUM> extends around a first axis <NUM> forming a first radius <NUM> and the posterior articulation <NUM> extends around a second axis <NUM> forming a second radius <NUM>. The first axis <NUM> may intersect the second axis <NUM>. In addition, the first radius <NUM> may be, for example, smaller than the second radius <NUM>.

The method shown in <FIG> may also be used to insert the implants <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Specifically, the method may include, for example, obtaining an implant <NUM> and making an incision to expose a joint with a first bone and a second bone <NUM>. The implant may be, for example, an implant <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as described in greater detail above with reference to <FIG> and which will not be described again here for brevity sake. The method may also include preparing the bones for receiving the implant <NUM>. Next, the method may include coupling the first member to the first bone <NUM> and coupling the second member to the second bone <NUM>. Then, the method may include inserting a second end of the insert into a first end of the first member <NUM>. In addition, the method may include engaging a locking tab of the insert with a locking groove of the first member <NUM>. In an embodiment, if the insert needs to be removed or replaced, for example, for a different size or due to wear, an instrument may be inserted into the slot of the insert to release the locking tab of the insert from the locking groove of the first member <NUM>. Finally, the method may include closing the incision <NUM>.

As may be recognized by those of ordinary skill in the art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present disclosure without departing from the scope of the disclosure. The components of the implants as disclosed in the specification, including the accompanying abstract and drawings, may be replaced by alternative component(s) or feature(s), such as those disclosed in another embodiment, which serve the same, equivalent or similar purpose as known by those skilled in the art to achieve the same, equivalent or similar results by such alternative component(s) or feature(s) to provide a similar function for the intended purpose. In addition, the implants may include more or fewer components or features than the embodiments as described and illustrated herein. For example, the components and features of <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> may be used interchangeably and in alternative combinations as would be modified or altered by one of skill in the art. Specifically, the first members <NUM>, <NUM>, <NUM>, <NUM>, the second members <NUM>, <NUM>, <NUM>, <NUM> and the inserts <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be used in alternative combinations as would be modified or altered by one of skill in the art. Accordingly, this detailed description of the currently-preferred embodiments is to be taken in an illustrative, as opposed to limiting of the disclosure.

It will be further understood that the terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has", and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a method or device that "comprises," "has," "includes," or "contains" one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that "comprises," "has," "includes," or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

Claim 1:
An implant (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), comprising:
a first member (<NUM>, <NUM>, <NUM>, <NUM>);
a second member (<NUM>, <NUM>, <NUM>, <NUM>), comprising:
a talus component comprising;
a first end (<NUM>, <NUM>, <NUM>, <NUM>) opposite a second end (<NUM>, <NUM>, <NUM>, <NUM>);
a first side (<NUM>, <NUM>, <NUM>, <NUM>) opposite a second side (<NUM>, <NUM>, <NUM>, <NUM>); and
a top surface (<NUM>, <NUM>, <NUM>, <NUM>) opposite a bottom surface (<NUM>, <NUM>, <NUM>, <NUM>), the top surface (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
a medial articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) extending from the first side (<NUM>, <NUM>, <NUM>, <NUM>) toward the second side (<NUM>, <NUM>, <NUM>, <NUM>) of the second member (<NUM>, <NUM>, <NUM>, <NUM>), wherein the medial articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) has at least one first curvature along a longitudinal axis and at least one second curvature perpendicular to the longitudinal axis;
a lateral articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) extending from the second side (<NUM>, <NUM>, <NUM>, <NUM>) of the second member (<NUM>, <NUM>, <NUM>, <NUM>) toward the first side (<NUM>, <NUM>, <NUM>, <NUM>), wherein the lateral articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) has at least one third curvature along the longitudinal axis and at least one fourth curvature perpendicular to the longitudinal axis;
wherein the medial articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) includes an anterior-medial sagittal radius and a posterior-medial sagittal radius; and
wherein the lateral articulating surface (<NUM>, <NUM>, <NUM>, <NUM>) includes an anterior-lateral sagittal radius and a posterior-lateral sagittal radius; and
an insert (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) with a top surface (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and a bottom surface (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the top surface (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) couples to the first member (<NUM>, <NUM>, <NUM>, <NUM>) and the bottom surface (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) engages the second member (<NUM>, <NUM>, <NUM>, <NUM>), characterised in that the anterior-lateral sagittal radius is larger than the anterior-medial sagittal radius and the posterior-medial sagittal radius is larger than the posterior-lateral sagittal radius.