Patent ID: 12208014

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This application is directed to orthopedic assemblies that enable a first portion thereof to be selectively coupled with a second portion to selectively position the first portion aligned with or eccentric to the second portion. The first portion can be co-linear with the second portion. In applications discussed in detail below, the first portion can include an articular body and the second portion can include a bone anchor portion to be coupled to a bone. For example in the context of the shoulder, a humeral head assembly can be provided that enables an articular surface or other aspect of an articular body to be coupled with a humeral anchor in a centered position or in an eccentric position. In some variations, a glenoid anchor could be provided and a shoulder assembly could enable an articular body such as a glenosphere of a reverse shoulder implant to be disposed in a centered or eccentric position relative to the anchor. In further variations, an assembly can be adapted for positioning an articular body of a femoral assembly relative to a femur anchor to provide for centered or eccentric positioning thereof for a hip or a knee assembly. In further variations, an assembly can be adapted for positioning an articular body of a tibial assembly relative to a tibial anchor to provide for centered or eccentric positioning thereof for a knee assembly. The ability to couple the articular surface in a centered or at one or more eccentric positions, or over a range of eccentric positions, allows a surgeon to treat a wider variety of patient anatomy with a kit that has fewer components than was possible in the past.

I. Centered Versus Eccentric Humeral Assemblies

FIG.1shows an example of a humeral head assembly10coupled with a humerus H. In a process of implanting the head assembly10in the humerus H, the shoulder joint space is surgically accessed and the humerus is separated from the glenoid cavity of the scapula. The head of the humerus H is separated from the rest of the humerus by cutting, or resecting, along a plane14. This resection creates an exposed surface S of the proximal humerus H. Thereafter, the intramedullary canal of the humerus (an elongated hollow space in the humerus) is accessed and may be enlarged or otherwise prepared. Thereafter, a stem30can be inserted into the canal leaving a coupling face40(SeeFIGS.1A and1B) of the stem30exposed at or accessible from the surface S. In alternative techniques, a stemless anchor is provided that does not require access to or preparation of the intramedullary canal. An articular body22can then be coupled with the stem30to form a humeral head assembly coupled with the humerus H, as shown inFIG.1.

Whether a stemless or a stemmed humeral anchor is used, the coupling face of that anchor, which is disposed at the surface S, may not necessarily be in the center of the surface S. This variable can be addressed by providing a kit having some humeral heads that are centered and some that are eccentric.FIG.1Ashows the stem30placed in the humerus H in a centered position. A coupling feature44at a center of the coupling face40of the stem30is aligned with a center48of the exposed surface S of the humerus H. In this configuration a humeral head50with a centered articular surface54can be used, e.g., is selected from the kit. A center of the articular surface54is intersected by, e.g., is co-linear with, a longitudinal axis56of a stem58of the humeral head50.FIG.1Bshows that in some cases, the process of resecting the humerus H and placing the stem30results in the coupling feature44being off-set from the center48of the exposed surface S of the humerus H. In this configuration a humeral head64with an eccentric articular surface68can be used, e.g., is selected from the kit. A center70of the articular surface68is not intersected by, e.g., is not co-linear with, a longitudinal axis72of a stem74of the humeral head64. Rather, there is a offset OS between the center70and the longitudinal axis72. The offset OS shifts the articular surface68toward the center48of the surface S of the humerus H, which is a preferred placement in many situations.

A kit with a plurality of humeral heads50,64can be provided. But, such a kit will contain at least one extra humeral head which is an inefficient approach.

II. Humeral Head Assemblies with Adjustable Eccentricity

The following embodiments facilitate providing a centered or a range of eccentric positions of a humeral head relative to a resected humeral surface that is more effective than past practice. The embodiment discussed below could be used in other orthopedic applications, including for providing centered or eccentric positioning of a glenosphere on a glenoid or scapular anchor, for providing centered or eccentric positioning of a femoral articular body on a femur anchor, for providing centered or eccentric positioning of tibial articular body on a tibial anchor, or for other orthopedic applications.

A. Continuous Adjustment and Discrete Adjustment of a Humeral Head

FIGS.2-11show embodiments of a humeral head assembly100in which eccentricity of the assembly can be adjusted as needed during implantation.FIG.3shows that an articular body104and a coupler108are separable components of the assembly100. The articular body104and the coupler108can be coupled in a number of different positions to facilitate the adjustment of or elimination of eccentricity. As discussed further below, the different positions can be arrived at along a continuous range of adjustment, by selecting a discrete position of one or more discrete positions, or by selecting among these modes of adjustment.FIGS.2,4and5illustrate a first configuration120of the humeral head assembly100. The first configuration120corresponds to a centered (or not eccentric) position.FIG.6illustrates a second configuration124an embodiment of the humeral head assembly100. The second configuration124corresponds to an eccentric position.

FIG.2shows that the articular body104can have an articular surface126. The articular surface126can be a convex surface. The articular surface126can be configured to engage with a concave surface of or at a glenoid of a patient.FIG.3shows that the articular body104also has a coupling portion128. The coupling portion128is disposed on a side of the articular body104opposite the convex articular surface126. The coupling portion128has a continuous zone140of eccentricity adjustment, shown inFIG.4. For example, shading inFIG.4indicates the zone140which is an area over which the articular body104can be positioned relative to the coupler108. The humeral head assembly100also has at least one site160for discrete positioning of the articular body104on the coupler108. There can be one, two, three, four, five, or more than five sites160. The discrete position site160allows for connecting the coupler108to the articular body104at one or more pre-defined positions and prevents relative rotation when so engaged. In some embodiments, the continuous zone140of eccentricity adjustment and the at least one discrete position site160are disposed in a same plane, e.g., in a plane transverse a normal to the center of the articular surface126. An amount of eccentricity can be selected in the continuous zone140or in the discrete position site(s)160at the same relative axial position of the coupler108and the articular body104. In some examples, the continuous zone140of eccentricity adjustment is located between discrete position sites160.FIG.4shows the coupler108engaged with the articular body104at one of five discrete position sites160.

FIGS.3and5shows that the coupler108can have a first portion200configured to mate with the articular body104and a second portion204opposite the first portion200. The first portion200can mate with the coupling portion128in one embodiment. The second portion204can mate with another member of a joint prosthesis (e.g. with the coupling feature44of the humeral stem30disposed at a surface S of the humerus H or with a stemless humeral anchor). In other applications, the second portion204can mate with another anchor member, such as at a glenoid or scapula, at an end of a femur or at an end of a tibia. In some embodiments, the coupler108is asymmetrical such that the second portion204has a longitudinal axis that is offset from a longitudinal axis of the first portion200. As will be discussed in more detail below, this offset can form a lateral offset between the center of the articular body104and the longitudinal axis of the second portion204when the humeral head assembly100is in an eccentric configuration, e.g., the second configuration124.

The articular body104can be configured to engage with and/or be retained by the coupler108. In some embodiments, the coupler108can engage with the coupling portion128of the articular body104to arrange or maintain the humeral head assembly100in the first centered (or non-eccentric) configuration120or in the second eccentric configuration124.

FIGS.5and5Aillustrate that the coupling portion128can include a first recess220disposed within the articular body104. The first recess220can have an open end221on a lateral side222of the articular body104. The lateral side222is a side of the articular body104opposite the articular surface126. The lateral side222faces away from the glenoid when the humeral head assembly100is implanted. The first recess220can extend to a recessed surface223. A second recess224can extend from the recessed surface223into the articular body104. The second recess224can have a closed end225and a diameter d1that is less than a diameter d2of the first recess220. In some embodiments, the second recess224can be tapered such that the diameter decreases over the length of the second recess224to a lesser diameter adjacent to the closed end. The second recess224can have a greater diameter toward the recessed surface223or toward the first recess220.

In some examples, the first portion200of the coupler108can be secured within the second recess224of the articular body104. In some embodiments, the coupler108can include a collar230that can be configured to be disposed in the first recess220. The collar230can be located between the first portion200and the second portion204of the coupler108, e.g., at a proximal end of the first portion200or at a distal end of the second portion204. The collar230can be used to position of the articular body104on or over the coupler108. In some embodiments, the collar230can include a protrusion234configured to secure the articular body104at any of the discrete position site(s)160of the articular body104. The protrusion234extends in a radial direction. The protrusion234extends in a plane perpendicular to a longitudinal axis of the coupler108. The protrusion234can fix a rotational position relative to the articular body104by circumferentially overlapping with a radial edge (e.g., a portion of a concavity, such as a notch, cavity, or recess) of the coupling portion128.FIG.4Ashows that the protrusion234can be configured to extend radially outward of a radially inward portion235of a circumferential edge237(e.g., a portion of a concavity, such as a notch, cavity, or recess disposed in the circumferential edge237) of the coupling portion128.

In some embodiments, when the first portion200of the coupler108is engaged with the second recess224of the articular body104, there is a clearance distance226between the closed end225of the second recess224and the top of the first portion200such that the top of the first portion200does not engage the closed end225of the second recess224. Similarly, in some embodiments, when the collar230of the coupler108is engaged with the first recess220of the articular body104, there is a clearance distance228between the recessed surface223and a top (or medial) side230aof the collar230such that the top (or medial side) of the collar230does not engage with the recessed surface223. Further, the coupler108can be engaged with the articular body104in a first engaged configuration that permits relative rotation, e.g., along the zone140. In the first engaged configuration the articular body104can be merely place or rested on the first portion200of the coupler108. The coupler108can be engaged with the articular body104in a second engaged configuration that prevents relative rotation and inadvertent disengagement once an amount of eccentricity (or no eccentricity) is selected. The second configuration can be provided by applying an impaction force to the articular body104while holding the coupler108generally stationary. The clearances distances226,228are each generally greater in the first engaged configuration than in the second engaged configuration due to the impaction force. The lesser (but non-zero) clearance distances226,228in the second engaged configuration can ensure that the coupler108and the articular body104can be coupled by an interference fit, such as a Morse taper.

FIG.4shows that the lateral side222of the articular body104can have indicia240A for aiding in positioning the articular body104over the coupler108along the continuous zone140. For example, the continuous zone140can provide for “+1” “+2” and “+3” to indicate adjustment with progressively more eccentricity. In some embodiments, the indicia240A corresponds to millimeters of offset (e.g., 1 mm, 2 mm, 3 mm of offset respectively) or can just indicate a progressively greater extent. Because the coupler108can be freely moveable along the zone140, eccentricity adjustment between a 0 mm offset and a 4 mm offset positions and also positions between the indicated positions can be provided, including, but not limited to, such as between +1 and +2, e.g., +1.5.

In some embodiments, the plurality of discrete position sites160can include radial notches244(or other radially extending edges capable of overlap) that provide for discrete eccentricity adjustments. In some embodiments, the radial notches244are configured to receive the protrusion234of the collar230. The profile, outline, edges, or shapes of the radial notches244can match or invert that of the protrusion234such as to provide a fixed position. In one embodiment, the notch244can be a negative of the protrusion234, e.g., the notch224can be concave where the protrusion234is convex. The concave notch244can have a portion that is radially inward of a radially outer portion of the protrusion234. SeeFIG.4Aand the corresponding description thereof. The protrusion234can be inserted axially into one of the notches244in the illustrated embodiment. The matching or inverted configurations, e.g., outline, edges, or shapes, of the protrusion234and the notches244prevented relative rotation between the coupler108and the articular body104when the protrusion234is engaged with the notch244. For example, as shown inFIG.4an opposing side231of the collar230disposed away from the protrusion234is closely adjacent to or in contact with an inner wall of the first recess220(adjacent to the +4 indicia) when the protrusion234is in the notch244at the +0 indicia. This contact or close adjacency and/or the shape of the notch244prevent or prevents the rotation of the coupler108within the body104unless the coupler108, and therefore the protrusion234, is retracted axially away from the body140until the protrusion234is spaced away from the surface222. Thus, the coupler108is at least radially secured to the articular body104when any one of the notches244receives the protrusion234. This condition is referred to above as a first engaged configuration. In other embodiments, a radially oriented detent can be provided between the articular body104and the coupler108. The radial notches244of the discrete position site160provides for discrete (e.g., “+0”, “+1”, “+2”, “+3”, and “+4”) eccentricity adjustments. The discrete positions corresponding to the sites160can be indicated by indicia240B. In some embodiments, the markings of the indicia240B corresponds to millimeters of offset (e.g., 0 mm, 1 mm, 2 mm, 3 mm, and 4 mm of offset respectively). In contrast to the continuous zone140, the discrete position site160provides for adjustments of eccentricity at specific, fixed increments and do not allow for intermediate position, e.g., +1.5.

In one embodiment, one or more radial notches244is provided without enclosing the protrusion234on both. For example, the notch244can provide a radially extending edge that provides a positive stop at one or both ends of the continuous zone140. In such embodiment, a position such as +0 or +4 can be confirmed by rotating the protrusion234into direct circumferential contact with such a notch. For example, inFIG.4Athe circumferential edge237extends between two radially inward portions. One of these two portions could be eliminated such that a stop is provided at an end of one or more of continuous zones of eccentricity adjustment. This configuration is elaborated upon inFIG.12Aand in the description thereof.

FIG.7-8Billustrate the articular body104in greater detail. As discussed above, one side of the articular body104includes the articular surface126. In this embodiment, the articular surface is convex, which presents an anatomical configuration. The articular body104has a height300and a width304that are configured to provide good fit in the shoulder joint space. In some examples, the height300of the articular body104can be between about 10 mm and about 30 mm, between about 13 mm, and about 27 mm. In some embodiments, the height of the articular body104can be about 13.0 mm, about 16.0 mm, about 18.0 mm, about 19.0 mm, about 27.0 mm, etc. The articular body104can be made of a variety of materials, such as CoCr, titanium, pyrocarbon, or other advantageous articular material and can include a solid or layered structure.

FIG.8Aillustrates further details of the coupling portion128. As discussed above, the coupling portion128includes the first recess220in the lateral side222. The first recess220is configured to receive the first portion200and the collar230of the coupler108. In some embodiments, the first recess220of the coupling portion128is offset from the center122of the articular body104. The first recess220coupling portion128can have an offset of between about 1.95 mm and about 2.05 mm, or can be about 1.95 mm, or about 2.00 mm, or about 2.05 mm from the center122of the articular body104.FIG.8Bshows that in one example, a longitudinal axis320of the second recess224intersecting the end225thereof and extending perpendicular to a plane of the lateral side222is offset from the center122of the articular surface126in this manner or by these amounts.

In the embodiment shown inFIG.8A, the continuous zone140forms an opening configured to accommodate the collar230and, for example, the protrusion234of the collar230through a range of eccentricity adjustments. The coupling portion128can include the indicia240A indicating the amount of eccentricity provided when the protrusion234is directed toward any of the various positions along the continuous zone140of the coupling portion128. For example, the coupling portion128inFIG.8Aindicates that the articular body104can be rotated along the continuous zone140to provide between 0 mm-1 mm of eccentricity adjustment (between the “+0” and “+1” indicia240A); between and including 1 mm-2 mm of eccentricity adjustment (between the “+1” and “+2” indicia240A); between and including 2 mm-3 mm of eccentricity adjustment (between the “+2” and “+3” indicia240A); and between 3 mm-4 mm of eccentricity adjustment (between the “+3” and “+4” indicia240A). In some embodiments, the continuous zone140can span an angle α4, providing about 122°4′ of movement. In the illustrated embodiments, eccentricity adjustment results from providing relative rotation between the articular body104and the coupler108. If the coupler108is disposed in a humeral, glenoid, scapular, femoral, or tibial anchor on the surface S of the humerus H, glenoid, scapula, femur, or tibia, and is held stationary, rotation of the articular body104causes the center122of the articular surface126of the articular body to move across the surface S. Thus, if the centered configuration120is initially provided in the situation illustrated inFIG.1B, the surgeon can provide eccentricity adjustment by rotating the articular body104through a selected degree of rotation to move the center122of the articular surface126toward the center48of the surface S. Thus, the offset illustrated inFIG.1Bcan be addressed with the second configuration124following some degree of eccentricity adjustment. In some embodiments, the continuous zone140can provide at least 90 degrees of eccentricity adjustment. In some examples, the continuous zone140can provide from about 90 to about 180 degrees of eccentricity adjustment.

In the embodiment shown inFIG.8A, each of the discrete position sites160is located at a corresponding radial notch244configured to receive the protrusion234of the collar230. In some embodiments, at least one of the radial notches244is disposed circumferentially adjacent to the continuous zone of eccentricity adjustment. Each of the radial notches244can prevent rotation of the articular body104relative to the coupler108, as discussed above, in an engaged configuration. The discrete position sites160correspond to indicia240B indicating the amount of eccentricity provided at each of the discrete position sites160. For example, the coupling portion128inFIG.8Aindicates that the humeral head assembly100can be rotated to each of the discrete position sites160to provide 0 mm of eccentricity adjustment (at the “+0” indicia240B); 1 mm of eccentricity adjustment (at the “+1” indicia240B); 2 mm of eccentricity adjustment (at the “+2” indicia240B); 3 mm of eccentricity adjustment (at the “+3” indicia240B); and 4 mm of eccentricity adjustment (at the “+4” indicia240B). In some embodiments, the position of no eccentricity (e.g. “+0” indicia240B) is 180 degrees rotationally offset from the position of maximum eccentricity (e.g. “+4” indicia240B).

In some embodiments, the coupling portion128is composed entirely of a continuous zone140. In some examples, the coupling portion128is composed entirely of a continuous zone140with a single discrete position site160, such as at a position corresponding to the centered configuration120, e.g. at the “+0” radial notch244if such embodiment includes discrete position indicia240B.

In some embodiments, the angle α1 between the “+0” radial notch244and the “+1” radial notch244is at or about 28°58′. In some embodiments, the angle α2 between the “+0” radial notch244and the “+2” radial notch244is at or about 60°. In some embodiments, the angle α3 between the “+0” radial notch244and the “+3” radial notch244is at or about 97°11′. In some embodiments, the angle α3 between the “+0” radial notch244and the “+4” radial notch244is at or about 180°.

FIG.8Aillustrates an eccentricity adjustment between the ranges of 0 mm-4 mm that can be achieved by engaging the coupler108with the continuous zone140of eccentricity adjustment or with the at least one discrete position site160for eccentricity adjustment. The continuous zone140can provide eccentricity adjustment through all values in the range of 0 mm-4 mm of eccentricity adjustment while the at least one discrete position site160provides precise eccentricity adjustment at pre-determined values (e.g. 0 mm, 1 mm, 2 mm, 3 mm, and 4 mm). In some embodiments, the coupling portion128is configured to allow a surgeon to adjust the articular body104in a clockwise or a counter-clockwise direction to achieve the desired eccentricity adjustment. This aspect can provide case of use for the surgeon as the articular body104can engage the coupler108at any orientation.

FIG.8Billustrates the first recess220and the second recess224extending into the articular body104. The first recess220can have a height220hof between about 2.669 mm and about 2.769 mm, or about 2.669 mm, about 2.719 mm, or about 2.769 mm, etc. As discussed above, the first recess220can be formed in or from the lateral side222and can form part of the coupling portion128in the articular body104.

The second recess224can extend from the first recess220into the articular body104. In some embodiments, the second recess224can have a height224hof about 8.60 mm. In some embodiments, the second recess224can have a tapered profile such that the diameter224dof the second recess224decreases as the second recess224extends into the articular body104. The diameter224dcan have a diameter that ranges from about 9.195 mm to about 9.235 mm. The second recess224can be configured to engage with the first portion200of the coupler108in a Morse taper or other form of interference fit. The tapered walls of the second recess224can allow the first portion200of the coupler108to be secured within the articular body104such that there is no relative movement between the articular body104and the coupler108, e.g., between the collar230and the lateral side222. In some embodiments, a longitudinal axis320of the second recess224can be offset from the center122of the articular surface126. In some embodiments the offset is disposed between a longitudinal axis320of the second recess224and the center122of the articular surface126.

FIGS.9-11illustrate various view of an embodiment of the coupler108. The first portion200of the coupler108can be configured to engage the articular body104. In some examples, the first portion200can have a height200hof between about 7.90 mm and about 8.10 mm, or about 7.90, 8.00 mm, or about 8.10 mm. In some embodiments, the first portion200can have a diameter200dat a free end thereof of between 9.205 mm and about 9.235 mm, or about 9.205 mm, about 9.220 mm, about 9.235 mm, etc. In some examples, the diameter200dof the free end of the first portion200is greater than the diameter224dof the second recess224at the end225but smaller than the diameter of the recess224at the surface223such that the first portion200can be received and secured within the second recess224.

The second portion204can be configured to mate with another member of a joint prosthesis (e.g. a coupling feature44disposed at a surface S of the humerus H, glenoid, scapula, femur, or tibia). In some examples, the second portion204can have a height204hof between about 11.90 mm and about 12.10 mm, or at about 11.90 mm, about 12.00 mm, or about 12.10 mm. In some embodiments, the second portion204can have a diameter204dof between about 9.205 mm and about 9.235 mm, or about 9.205 mm, about 9.220 mm, or about 9.235 mm, etc. In some examples, the diameter204dcan change over its length and range from about 9.205 mm to about 9.235 mm.

The coupler108can include the collar230at the distal end of the first portion200. The collar230can be configured to fit within the first recess220of the articular body104. In some examples, the collar230can have a height of between about 2.45 mm and about 2.55 mm, or at about 2.45 mm, about 2.50 mm, or about 2.55 mm. In some examples, the collar230can include the protrusion234, which as discussed above, is configured to be retained within one of the radial notches244of the at least one discrete position sites160or to be disposed within or along the continuous range140.

In some examples, the coupler108is asymmetrical such that the second portion204had a different longitudinal axis340than a longitudinal axis344of the first portion200. The longitudinal axis340can be aligned with the center122of the articular body104(e.g., when the protrusion234is aligned with the +0 site160). When so aligned, the assembly100will provide a non-eccentric arrangement as inFIG.1A. The longitudinal axis340can be offset from the center122of the articular body104(e.g., when the protrusion234is not aligned with the +0 site160). When so offset, the assembly100will provide an eccentric arrangement as inFIG.1B. As illustrated inFIGS.9-11, the distance between the longitudinal axis340of the second portion204and the longitudinal axis344of the first portion200forms an offset OS. In some embodiments, the offset OS can range between about 1.95 mm and about 2.05 mm, or can be about 1.95 mm, or about 2.00 mm, or about 2.05 mm.

In some embodiments, when the coupler108is engaged with the articular body104, the first portion200of the coupler108aligns with the longitudinal axis320of the second recess224. As discussed above and shown inFIG.8B, the longitudinal axis320of the second recess224is offset from the center122of the articular surface124. In some examples, as the coupler108is asymmetrical, the longitudinal axis340of the second portion204may or may not align with the center122of the articular surface124depending on the arrangement of the humeral head assembly100. As discussed above in connection withFIGS.2and4-5A, when the humeral head assembly100is in the centered configuration120, the center122of the articular surface124can be co-linear with the longitudinal axis340of the second portion204. In contrast, when the humeral head assembly100is in the eccentric configuration124as shown inFIG.6, the longitudinal axis340of the second portion204is offset from the center122of the articular surface124. The foregoing shows that the humeral head assembly100can provide the configuration ofFIG.1Aand a range of eccentric configurations including that ofFIG.1Band thus is a very adaptable assembly and further is able to reduce the complexity of surgical kits and any unused components thereof.

B. Humeral Head with a Plurality of Continuous Adjustment Zones

FIGS.12and12Aillustrate other embodiments of articular bodies404,404A that can form part of a humeral head assembly similar to the humeral head assembly100. The discussions of the articular body104and the humeral head assembly100set forth above that are relevant to the discussion of the articular body404and to the articular body404A will not be repeated, but one skilled in the art will understand that such discussions shall supplement the following discussion of the articular body404.

The articular body404has a coupling portion408, as illustrated inFIG.12. The coupling portion408forms a first recess420in the articular body404. The coupling portion408can include a plurality of continuous zones424(denoted by shaded regions). The continuous zones424can be separated by one or more discrete position sites428. As with the coupling portion128, each of the discrete position sites428can include a radial notch432. In some embodiments, the continuous zone424of eccentricity adjustment and the one or more discrete position sites428are disposed in a same plane, e.g., in a plane parallel to the lateral side222, located between the side222and the articular surface (not shown but located opposite the side222). In some examples, the continuous zone424of eccentricity adjustment is located between discrete eccentricity positions (e.g., discrete position sites428).

The coupling portion408can be configured to engage with the collar230of the coupler108. The plurality of continuous zones424form an opening configured to accommodate the collar230and, for example, the protrusion234of the collar230through a range of eccentricity adjustments. The coupling portion408can include a plurality of indicia436indicating the amount of eccentricity provided at various positions along the continuous zones424. In the coupling portion408, the articular body404can be rotated in either direction to engage with one of the continuous zones424to provide between 0 mm-1 mm of eccentricity adjustment (between the “+0” and “+1” indicia436); between and including 1 mm-2 mm of eccentricity adjustment (between the “+1” and “+2” indicia436); between and including 2 mm-3 mm of eccentricity adjustment (between the “+2” and “+3” indicia436); and between 3 mm-4 mm of eccentricity adjustment (between the “+3” and “+4” indicia436). In some embodiments, either one of the continuous zones424can provide at least 90 degrees of eccentricity. In some examples, either one of the continuous zones424can provide from about 90 to about 180 degrees of eccentricity.

In some embodiments, the continuous zones424of the plurality of continuous zones are symmetrical. In some embodiments, the continuous zones424of the plurality of continuous zone are asymmetrical.

The embodiment of the coupling portion408can include two discrete position sites428on opposite sides of the coupling portion408. Each of the discrete position sites428form radial notches432that are configured to receive the protrusion234of the collar230. In some embodiments, at least one of the radial notches432is disposed circumferentially adjacent to the continuous zone of eccentricity adjustment. As discussed above, each of the radial notches432can prevent rotation of the articular body404relative to the coupler108. To move from one of the notches432to another of the notches or from one of the notches432to one of the continuous zones424, the coupler108must be axially disengaged from the articular body404such that at least the collar230is removed from the first recess420. In other embodiments, a detent structure can provide mechanical feedback to the user to indicate engagement in a discrete location, e.g., within any of the radial notches432. Like the continuous zone424, each of the discrete position sites428can include indicia436indicating the amount of eccentricity provided at each of the discrete position sites428. In the embodiment illustrated inFIG.12, the coupling portion408includes two discrete position sites428—at 0 mm of eccentricity adjustment (at the “+0” indicia436) and at the 4 mm of eccentricity adjustment (at the “+4” indicia436). In some embodiments, the position of no eccentricity (e.g. “+0” indicia436) is 180 degrees rotationally offset from the position of maximum eccentricity (e.g. “+4” indicia436).

The coupling portion408ofFIG.12differs from the coupling portion128in that it includes two continuous zones424. In this embodiment, a surgeon would be able to confirm through contact with and subsequent engagement in the notches432of the discrete position site360when the articular body404is centered on the coupler108and when the articular body104is positioned at maximum eccentricity (e.g. 4 mm). Between those ranges, the surgeon is able to freely adjust the position of the articular body404about the coupler108.

FIG.12Ashows further details of the articular body404A. As discussed the articular body404A is similar to the articular body404except as described differently below. The discussion of the articular body404and the other articular bodies are intended to supplement the following discussion and will not be repeated. The articular body404A includes a coupling portion408A. The coupling portion408A includes a first recess420and a second recess224can extend from the first recess420. The first recess420can be bounded by a plurality of zones or wall segments. The first recess420can be bounded by one or a plurality of continuous zones424. One or both of the continuous zones424can extend to an end formed by a stop429.FIG.12Ashows that a stop429can be provided at each end of a first continuous zone424. The stops429can include curved protrusions that extend to peaks disposed into the first recess420. The peaks of the stops429can extend about one-quarter of the width of the first recess420from the continuous zones424toward the second recess224. In the illustrated embodiment two continuous zones424are provided on opposite sides of the second recess224.

The continuous zones424can be symmetrical about a line intersecting the stops429, e.g., connecting the peaks of the stops429. In some embodiments the coupling portion408A of the articular body404A is not symmetrical such that the indicia436are not spaced apart by the same amount.FIG.12Ashows that the indicia436disposed in the portion of the lateral side222located in a clockwise direction from +0 correspond to providing 0, 1, 2, or 3 mm of offset. More specifically, when the protrusion234of the coupler108is advanced into the first recess420and is aligned with the +0 of the indicia436no additional offset is provided. When the protrusion234is advanced into the first recess420and is aligned with the +1 of the indicia436an additional offset of +1 mm is provided. The indicia436that are disposed on the portion of the lateral side222located in a clockwise direction from +4 correspond to providing a different range of additional offset. The indicia436on this portion of the lateral side222indicate a range of adjustment from +1 to +4 mm of additional offset.

The stops429differ from the radial notches432of the discrete position sites428in not being able to enclose the protrusion234on both sides when the protrusion234is aligned with one of the indicia436centered on the radial notches432. Rather, the engagement of the protrusion234is made by contacting one side thereof with one side of the stops429. An advantage of this is that when the coupler108is advanced into the first recess420and the protrusion234is contacting either one of the stops429motion away from the offset position provided at this relative position can be accomplished without having to withdraw the collar230out of the first recess420. Immediate relative rotation of the articular body404A on the coupler108can be provided to move from any of the discrete positions to any other position. The engagement of the protrusion234with the stops429can be easily confirmed in a tactile manner without requiring any rotational alignment of the protrusion234with a notch.

One further variation of an assembly can be provided by modifying the coupler108such that the collar230has a concave periphery that is configured to either receive the stops429or if not aligned therewith to be positional along the continuous zones424in the first recess420. This modification would provide that both sides of the stops429would be received within the concave recess of the modified coupler108such that in this variation movement from the discrete positions defined by the stops429to the continuous zones424would require retracting the modified collar of the coupler108from the first recess420.

C. Eccentric Adjustment at an Interface Partially Formed on a Humeral Anchor

FIGS.13A-13Cillustrate another embodiment of a coupling portion528. The discussions of the coupling portion128set forth above that are relevant to the discussion of the coupling portion528will not be repeated, but one skilled in the art will understand that such discussions shall supplement the following discussion of the coupling portion528.

The coupling portion528can be located between the articular surface of an articular body (e.g. articular body104, articular body404) and an end of a bone anchor500. As discussed above, in some embodiments, the coupling portion can be located on a surface of the articular body (e.g. opposite the convex articular surface). In some embodiments, the coupling portion528can be located in an end of the bone anchor500.FIGS.13A-13Cillustrate a bone anchor500having a stem530, but in some embodiments, the bone anchor can be stemless. Examples of stemless bone anchors are found in US2016/0324648 and in U.S. 62/368,036, both of which are hereby incorporated by reference herein in their entireties.

The coupling portion528illustrated inFIGS.13A-13Cis similar to the coupling portion128of the humeral head assembly100disclosed above. However, the coupling portion408illustrated inFIG.12,12A, or any of the other coupling portions disclosed herein can similarly be located in a surface of the bone anchor500(e.g. stem or stemless).

The coupling portion528forms a first recess520in a medial surface of the stem530. The coupling portion528can include a continuous zone540and at least one discrete position site560(denoted by a shaded region). The coupling portion528can include at least one discrete position site(s)560. As with the coupling portion128, each of the discrete position sites560can include a radial notch544or other radially extending edge configured to radially overlap with a portion of a coupler, as discussed below. In some embodiments, the continuous zone540of eccentricity adjustment and the at least one discrete position site560are disposed in a same plane, e.g., in a plane lateral to but parallel with the medial surface of the stem530. In some examples, the continuous zone540of eccentricity adjustment is located between discrete eccentricity positions (e.g., discrete position sites560).

The coupling portion528can be configured to engage with a collar630of a coupler608that can be engaged with the coupling portion528. The continuous zone540forms an opening configured to accommodate the collar630and, for example, a protrusion634of the collar630through a range of eccentricity adjustments. The coupling portion528can include a plurality of indicia540A indicating the amount of eccentricity provided at various positions along the continuous zone540. The coupler608can be rotated in the coupling portion528to provide between 0 mm-1 mm of eccentricity adjustment (between the “+0” and “+1” indicia540A); between and including 1 mm-2 mm of eccentricity adjustment (between the “+1” and “+2” indicia540A); between and including 2 mm-3 mm of eccentricity adjustment (between the “+2” and “+3” indicia540A); and between 3 mm-4 mm of eccentricity adjustment (between the “+3” and “+4” indicia540A). In some embodiments, the continuous zone540can provide at least 90 degrees of eccentricity. In some examples, the continuous zone540can provide from about 90 to about 180 degrees of eccentricity.

One or more of the plurality of discrete position sites560can include radial notches544that are configured to receive the protrusion634of the collar630. In some embodiments, at least one of the radial notches544is disposed circumferentially adjacent to the continuous zone of eccentricity adjustment. As discussed above, each of the radial notches544can prevent rotation of the coupler608relative to the coupling portion528in the surface of the stem530. The notches allow for a first engaged configuration in which rotation is prevented but the coupler608and the anchor500are not secured in an interference fit and can be easily disengaged. To move from one of the radial notches544to another of the notches or from one of the radial notches544to the continuous zone540, the coupler608can be axially disengaged from (e.g., moved medially relative to) the medial surface of the stem530such that at least the collar630is removed from the first recess520. In other embodiments, a portion of a detent structure can be provided to indicate to the user a rotationally engaged configuration. Like the continuous zone540, each of the discrete position sites560can include indicia540B indicating the amount of eccentricity provided at each of the plurality of discrete position site560. In the embodiment illustrated inFIGS.13A-13C, the coupling portion528includes four (4) discrete position sites560—at 0 mm of eccentricity adjustment (at the “+0” indicia540B), at 1 mm of eccentricity adjustment (at the “+1” indicia540B), at 2 mm of eccentricity adjustment (at the “+2” indicia540B), at 3 mm of eccentricity adjustment (at the “+3” indicia540B), and at the 4 mm of eccentricity adjustment (at the “+4” indicia540B). In some embodiments, the position of no eccentricity (e.g. “+0” indicia540A) is 180 degrees rotationally offset from the position of maximum eccentricity (e.g. “+4” indicia540A).

In some embodiments, the first recess520of the coupling portion528opens up to a second recess524. The second recess524can have a smaller diameter than the first recess520. The second recess524can be configured to receive a tapered end portion of the coupler608. The tapered end portion can be similar to the first portion200of the coupler108. In the illustrated embodiment, the tapered end portion is aligned with a center of the second recess524. A medial end632of the coupler608projects medially from the collar630. The medial end632of the coupler608is configured to engage a recess in an articular body that can be similar to the articular body104. The longitudinal axis of the medial end632of the coupler608is offset from the tapered end (and from the center of the second recess524) such that rotation of the coupler608along the continuous zone540or to any of the discrete position sites560results in adjustment of the extent of eccentricity (if any) to provide for centering of the articular body over the resected surface of the humerus even if the anchor500is not centered on the resected surface.

FIGS.14A-14Cshow that the foregoing embodiments can also be applied to a reverse shoulder assembly. A reverse shoulder assembly is one in which the natural articular surfaces of the humerus are modified such that a convex articular surface is provided on the scapula and a concave articular surface is provided on the humerus.FIG.14Ashow an exploded view of the anchor500and a tray700of a reverse shoulder assembly. The anchor500can have any of the features discussed above. The anchor500also can have any combination of continuous and position sites.FIG.14Ashows the notches544formed within the first recess520. The anchor500also includes the second recess524which extends from the first recess520further into the anchor500.

The tray700can have a taper704projecting from a humeral facing wall724and a recess on the opposite side of the tray700from the humeral facing wall724. The recess can be partly defined by an inner circumference712which is surrounded by an inner sidewall716. The tray700can be configured to securely retain an articular body (not shown) which is inserted into the recess in the space surrounded by the inner sidewall716. The inner sidewall716can have one or a plurality of fins720disposed about the inner sidewall716. The fins720can be configured to engage an outer sidewall of the articular body to hold the articular body in place in one embodiment. The articular body has a concave articular surface as discussed above.

FIG.14Bshows further details of the tray700. The tray700can be symmetrical, e.g., having a circular outer periphery about the humeral facing wall724. The tray700can have a center728from which a radius of the circular periphery can be measured. In various advantageous embodiments the center728is disposed offset from a center732of the taper704. The off-set distance between center728and the center732enables a rotation of the tray700relative to the anchor500to change the location of the tray700(and thereby the articular body coupled therewith) relative to the resected face of the humerus. Thus, even if the anchor500is off-set from the center of the humerus the tray700can be rotated relative to the anchor500to a position in which the center728is centered, substantially centered or closer to the of the humerus than the second recess524or the taper704. The tray700can include a protrusion708that can be aligned to discrete or continuous zones as discussed further below.FIG.14Cshows the opposite side of the tray700shown inFIG.14B. The side shown inFIG.14Cfaces the scapula when the tray700is implanted and may be referred to as a medial side. The tray700includes a wall730that is located opposite the humeral facing wall724. The wall730and the inner sidewall716at least partially define a concave space729in which an articular insert can be disposed. In one embodiment indicia731are provided on the medial side, e.g., on the wall730to facilitate alignment of the tray700relative to the anchor. The indicia731on the wall730can be aligned with the indicia on the anchor500to provide the off-set position indicated. For example, the protrusion708can be placed in the +0 position on the anchor500and when so placed the +0 mark of the indicia731will be aligned with the +0 on the anchor500. When the tray700is rotated such that the +1 mark of the indicia731is moved to the horizontal position (where +0 is inFIG.14C) the surgeon can know that the protrusion708is aligned with +1 in the upper (as depicted inFIG.14A) continuous zone of the anchor500. When the tray700is rotated such that the +2 mark of the indicia731is moved to the horizontal position the surgeon can know that the protrusion708is aligned with +2 in the upper continuous zone of the anchor500. When the tray700is rotated such that the inverted +1 mark of the indicia731is moved to the horizontal position the surgeon can know that the protrusion708is aligned with the inverted +1 in the lower portion of the anchor500. Visual confirmation on the tray700may not be required for discrete zones (as in the lower portion of the anchor500) but still provides a convenient visual confirmation. Also, the anchor500can be provided with upper and lower continuous zones, similar to the arrangements ofFIGS.12and12A. The indicia731thus can give a visual confirmation of the position of the tray700relative to the anchor500. The visual confirmation enables the surgeon to accurately position the tray700and also to make a record during the surgery of the position to enhance the patient's medical record.

A method of implanting a humeral assembly including the anchor500and the tray700can include surgically exposing the humerus at the shoulder. The humerus is then resected to create the exposed surface S (seeFIG.1). The anchor500can thereafter be placed in the humerus by creating a space in the cancellous bone of the humerus for a stemmed anchor. If a stemless anchor is used, less or no additional bone preparation may be required. The tray700can be used to provide an adjustment of the position of the tray700(and an articular body coupled therewith) if following placement the position of anchor500it is determined that some adjustment is needed. For example, the tray700can be advanced as indicated by arrow A to be coupled with the anchor500by advancing the taper704into the second recess524until the tray700comes to rest on the anchor500. The tray700can be rotationally oriented in either direction of the arrow B as the tray700is advanced into first recess520and the second recess524. In one technique the protrusion708is initially aligned with the +0 position such that no additional offset is provided, e.g., the center728is aligned with the center of the second recess524. If offset is needed the protrusion708can be moved along the continuous zone540to +1, +2, +3, or any other position therebetween. The protrusion708can be moved to any one of the notch544, e.g., to the +1, +2, +3, or +4 positions. The position can be visually confirmed by reference to the indicia731as discussed above. Once alignment is confirmed the tray700can be secured to the anchor500by engaging the taper704with the walls of the second recess524, e.g., in a Morse taper connection. The method can include selecting between two continuous zones of adjustment in some embodiments of the anchor500. After the tray700is secured to the anchor500a reverse articular body can be coupled with the tray700within the inner sidewall716, e.g., by engaging the fins720.

Although the anchor500has been illustrated as configured for implantation in a humerus, the anchor500could be adapted for implantation within a glenoid, scapula, femur, or tibia and still provide advantageous positioning of an articular body thereon in a centered or over a range of eccentric positions as discussed herein.

III. Methods of Assembling the Centered and Eccentric Humeral Head Assembly

The humeral head assembly100described allows a surgeon to treat a wider variety of patient anatomy with a kit including fewer components. The articular body104and the coupler108are adjustable relative to each other such that the humeral head assembly100can be used in the centered configuration120or the eccentric configuration124. Although the method below is discussed in connection with the humerus, as discussed herein the assembly100and the bone anchor500and the coupler608can be deployed in other orthopedic applications such as in implanting a glenosphere in a glenoid, a femoral articular body on an end of a femur (e.g., for hip or knee procedures) or for implanting a tibial articular body at an end of a tibia for a joint procedure.

The method of assembling the humeral head assembly100can include engaging a first end (e.g. the first portion200) with the coupler108of the articular body104. The method can then include providing relative rotation between the articular body104about the first end (e.g., the first portion200) of the coupler108. The relative motion can be along a continuous zone140of rotational positions while the first end (e.g., the first portion200) is partially inserted into the coupling portion128. As well, the method can include providing relative rotation to align the coupler108with a discrete position site160.

The method of assembling the humeral head assembly100can include selecting an amount of eccentricity corresponding to a position within the continuous zone140of rotational position or to the at least one discrete position site160. As described with regard toFIGS.3,8A,12, and13C, the continuous zone140,540and the at least one discrete position site160,560allow the surgeon to select the amount of eccentricity adjustment required by adjusting the position of the collar230within the articular body104or by adjusting the position of the collar530within the anchor500.

The method of assembling the humeral head assembly100can include securing the articular body104about the first end (e.g. first portion200) of the coupler108at the selected amount of eccentricity within the continuous zone140or the at least one discrete position site160. The method of assembling the humeral head assembly including the anchor500can include securing the coupler608within the anchor500about the tapered end of the coupler608at the selected amount of eccentricity within the continuous zone540or the at least one discrete position site560. As described above inFIG.8A-8B, the second recess224can be configured to receive the first portion200. As the walls of the second recess224are tapered and gradually reduce in diameter, the second recess224can be press-fit or interference fit, e.g., with a Morse taper, about the first portion200to secure the articular body104to the coupler108to prevent relative movement between the articular body104and the coupler108. Similarly the second recess524can be tapered to receive the tapered end portion of the coupler608resulting in a Morse taper connection.

In some embodiments, the method of assembling the humeral head assembly100includes aligning the alignment feature (e.g. the protrusions234,634of the collars230,638) with an eccentricity amount indicia240A,240B,540A,540B disposed on or adjacent to the coupling portion128,538of the articular body104or of the anchor500.

In some embodiments, the method of assembling the humeral head assembly100can also include positioning the protrusion234of the collar230(or protrusion634) within a radial notch244(or notch544) of one of the discrete position sites160(560). This can also be configured to prevent relative rotation of the coupler108with the articular body104(or of the coupler608with the anchor500).

The apparatuses and methods herein can enable either of the situations illustrated inFIGS.1A and1Bto be treated using only one articular body104and only one coupler108coupled with a bone anchor or with one anchor500, one coupler608and an articular body. In the past, commercial systems provided kits with multiple articular body/coupler combinations that were pre-assembled. Thus, the present application enables a wide range of patients to be treated with fewer components, simpler systems, and less cost.

Terminology

Although certain embodiments have been described herein, the implants and methods described herein can interchangeably use any articular component, as the context may dictate.

As used herein, the relative terms “proximal” and “distal” shall be defined from the perspective of the implant. Thus, proximal refers to the direction of the articular component and distal refers to the direction of an anchor component, such as a stem of a humeral anchor or a thread or porous surface or other anchoring structure of a stemless anchor when the implant is assembled.

Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.

The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. In addition, the articles “a,” “an,” and “the” as used in this application and the appended claims are to be construed to mean “one or more” or “at least one” unless specified otherwise.

The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example ±5%, ±10%, ±15%, etc.). For example, “about 1” includes “1.” Phrases preceded by a term such as “substantially,” “generally,” and the like include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example, “substantially spherical” includes “spherical.” Unless stated otherwise, all measurements are at standard conditions including temperature and pressure.

As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: A, B, or C” is intended to cover: A, B, C, A and B, A and C, B and C, and A, B, and C. Conjunctive language such as the phrase “at least one of X, Y and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be at least one of X, Y or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y and at least one of Z to each be present.

Although certain embodiments and examples have been described herein, it should be emphasized that many variations and modifications may be made to the humeral head assembly shown and described in the present disclosure, the elements of which are to be understood as being differently combined and/or modified to form still further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or indispensable.

Some embodiments have been described in connection with the accompanying drawings. However, it should be understood that the figures are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear an exact relationship to actual dimensions and layout of the devices illustrated. Components can be added, removed, and/or rearranged. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, it will be recognized that any methods described herein may be practiced using any device suitable for performing the recited steps.

For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Moreover, while illustrative embodiments have been described herein, it will be understood by those skilled in the art that the scope of the inventions extends beyond the specifically disclosed embodiments to any and all embodiments having equivalent elements, modifications, omissions, combinations or sub-combinations of the specific features and aspects of the embodiments (e.g., of aspects across various embodiments), adaptations and/or alterations, and uses of the inventions as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the actions of the disclosed processes and methods may be modified in any manner, including by reordering actions and/or inserting additional actions and/or deleting actions. It is intended, therefore, that the specification and examples be considered as illustrative only, with a true scope and spirit being indicated by the claims and their full scope of equivalents.

Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “inserting a humeral stem into a humerus” include “instructing insertion of a humeral head into a humerus.”